parallel application of blends of natural gas and hydrogen in ...6.5.3 technical features of...

CENTRO LOMBARDO PER LO SVILUPPO TECNOLOGICO E PRODUTTIVO DELL’ARTIGIANATO E DELLE PICCOLE IMPRESE

“parallel application of Blends Of Natural Gas and HYdrogen in internal combustion

engines and fuel cells”

BONG-HY

Document: FINAL REPORT

Date: MARCH 2007

Contributions: Municipality of Brescia ASM SpA (Brescia) Catholic University of the Sacred Heart – BRESCIA ENEA University of Tor Vergata

SINTESI AB University of Applied Sciences of Linz

University of Applied Sciences of Esslingen Kompetenz und Innovationzentrum Brennstoffzelle der Region Stuttgart (KIBZ)

Code:

REGINS Verified:

Approved:

INTESTAZIONE DI PAGINA

INDEX 1. SUB-PROJECT DEFINITION 4 2. ABSTRACT 5 3. PARTICIPANTS 6

3.1. PRESENTATION OF THE MUNICIPALITY OF BRESCIA 6 3.2. PRESENTATION OF THE UNIVERSITY OF APPLIED SCIENCES UPPER AUSTRIA RESEARCH & DEVELOPMENT 6

3.3. PRESENTATION OF THE UNIVERSITY OF APPLIED SCIENCES OF ESSLINGEN 6 3.4. PRESENTATION OF THE KOMPETENZ UND INNOVATIONZENTRUM BRENNSTOFFZELLE DER REGION STUTTGART (KIBZ) 7 3.5 PRESENTATION OF ASM SPA 7

4. OBJECTIVES 8 5. PROJECT CHARACTERISTICS 9

5.1. PROJECT DURATION 9

5.2. PROJECT METHODOLOGY 9 5.3. PARTNERSHIP 11 5.4. GANTT DIAGRAM OF THE PROJECT 11 5.5. FINANCIAL PLAN 12

6. PROJECT RESULTS 13 6.1 WP1 - SIMULATION OF THE COMBUSTION OF H2/NG BLENDS AND VALIDATION OF THE CODE 13 6.1.1 Introduction 13 6.1.2 Modelling Issues 14 6.1.3 Turbolent combustion modelling 15 6.1.4 Laminar flame speed calculation details 16 6.1.5 Analysis of results 17 6.1.6 Conclusions 24 6.2 WP2 - STATE OF THE ART OF THE USE OF H2/NG BLENDS AND ANALYSIS OF THE PRO AND CONS OF THE INTRODUCTION OF AN ADVANCED FUEL IN ASM SPA FLEET 25 6.2.1 Introduction 25 6.2.2 Infrastructures needed for the refuelling of blends of hydrogen and natural gas vehicles 27 6.2.3 The duty cycle of the urban waste collecting vehicle 28 6.2.4 Characterisation of the atmospheric emissions and greenhouse gases thanks to the use of blends in function of the percentage of hydrogen (by volume) in the fuel 29 6.3 WP3 - MODIFICATION, TEST AND OPTIMISATION OF AN ICE 35 6.3.1 Introduction 35 6.3.2 Methane - Hydrogen mixtures 37 6.3.3 Experimental setup 38 6.3.4 Measurement system 38 6.3.5 Tests on ENEA roller bench 40 6.3.6 Results 42 6.3.7 Conclusions 43 6.4 WP4 - STUDY OF THE USE OF H2/NG IN A SOFC AND RELATED TESTS 44

BONG-HY – FINAL REPORT – MARCH 2007

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6.5 WP5 - ANALYSIS OF THE REGULATIONS FOR THE USE OF H2/NG BLENDS AND HOMOLOGATION PROCEDURES FOR SINGLE VEHICLE PROTOTYPES 48 6.5.1 Introduction 48 6.5.2 Technical considerations on the combustion of CH4/H2 blends in internal combustion engines 50 6.5.3 Technical features of hydrogen and H2/NG blends for their use in an internal combustion engine (ICE) 53 6.5.4 Performances and polluants emissions of an ICE fuelled by blends of hydrogen and methane - Literature data 54 6.5.5 ISO STANDARDS - Normative activity on hydrogen and CNG/H2 blends 56 6.5.6 ISO/TC 197 "Hydrogen technologies" 56 6.5.7 ISO/TC22/SC25 "Vehicles using gaseous fuels (CNG, LPG, H2)" 58 6.5.8 ISO/TC22/SC21 "Electrically propelled road vehicles" 60 6.5.9 TC58 "Gas cylinders" 61 6.5.10 ECE-ONU/UN-GTR Regulations 62 6.5.11 European Commission projects for the homologation of H2 vehicles 65 6.5.12 Development of national regulations in Italy for the inspection of hydrogen of CH4/H2 vehicle 68 6..5.13 Mirror Committee H2 ITALIA 68 6.5.14 Inspection Procedure as single prototypes (in Italy) 71 6.5.15 Risk Analysis ( RAMS) 73 6.5.16 Hypothesis of a test plan for inspection in Italy 74 6.5.17 Conclusions 75 6.6 WP6 - INTERVIEWS TO DIFFERENT KEY PLAYERS ABOUT BARRIERS AND CONSTRAINTS 76 6.6.1 Results of interviews 76 6.7 WP7 - LAB TESTS ON THE COMPONENTS OF THE AUSTRIAN SOFC TO STUDY THE AGEING PROCESSES DUE TO THE USE OF H2/NG BLENDS 78 6.7.1 Samples 78 6.7.2 Preparation 78 6.7.3 Results 78 6.7.4 Conclusions 79 6.8 WP8 - DIFFUSION OF RESULTS AND PREPARATION OF NEW PROPOSALS 85

7. POSSIBLE FUTURE DEVELOPMENT 87 8. ATTACHMENTS 89 BIBLIOGRAPHY 90


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1. SUB-PROJECT DEFINITION

Title: parallel applications of Blends Of Natural Gas and HYdrogen in internal combustion engines and fuel cells Acronym: BONG-HY Thematic area : Automotive Call: Third call

Start Date 01.01.06 End Date 30.11.06 Duration in months 11

Total Budget € 251.192,53Total Budget Upper Austria (Sum of all Participants of UA) € 82.646,00Total Budget Baden-Württemberg (Sum of all Participants of B-W) € 20.000,00Total Budget Lombardy Region (Sum of all Participants of LR) € 148.546,53Total Budget West Pannonia (Sum of all Participants of WP) € 0.00

Cofinancing for the Lombardy Region: 100% Cofinancing for the Upper Austria Region: 50% Cofinancing for the Stuttgart Region: 50%


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2. ABSTRACT

The project had aimed at testing blends of H2 and CH4 both in an ICE and in a SOFC with respect to the use of pure CH4, in order to evaluate the potential environmental and energetic benefits. Concerning the tests of the blends in an ICE of an IVECO DAILY, a consistent reduction of CO, HC and NOX emissions had been measured: in particular, very lean blends with high fuel/air ratios (λ = 1.4) had showed the almost complete abatement of CO but an increase of HC emissions by the 40%. Nevertheless, the use of stoichiometric blends (λ = 1) along with a variation of the spark advance had led to a reduction of CO, HC and NOX emissions ( an NOX reduction of about the 60-70% had been measured with respect to the use of pure CH4). The pollutants emissions abatement had been accompanied by a reduction of CO2 emissions by the 15% and 20% with blends with a hydrogen content of 10% and 15% by volume respectively. Concerning the application of the blends in a SOFC, both its electrical performance and the degradation of its components had been tested. It had been verified that a 10% methane content in hydrogen by volume can represent the upper limit for the use of blends in a SOFC (over this limit there are decreases of up to the 50% of the power developed by the FC after just 1000 min of operation, along with a consistent carbon deposit on the anode that can cause diffusion problems). BONG-HY had foreseen 8 workpackages (WPs): WP1 – Simulation of the combustion of H2/NG blends and validation of the code (LRPP1) WP2 – State-of-the-art of the use of H2/NG blends and analysis of pro and cons of introduction of an advanced fuel in ASM SPA fleet (LRPP1) WP3 – Modification, test and optimization of an Internal Combustion Engine (LRPP1) WP4 – Study of the use of H2/NG blends in a SOFC and related tests (UAPP1) WP5 – Analysis of regulations for the use of H2/NG blends and homologation procedures for the vehicles (LRPP1) WP6 - Interviews to different key players about barriers and constraints linked to the use of blends as a fuel for mobility (BWPP2) WP7 - Lab tests concerning the analysis of the electrodes and ageing processes of the Austrian SOFC fuelled with blends (BWPP1) WP8 - Diffusion of results and preparation of new proposals (LRPP1 - BWPP2) Since most of the activities in the workpackages had been carried out by ASM SpA, a municipalized multiutility, owned by the Municipality of Brescia for the 70%. ASM SpA had conducted lab tests on one of their light duty vehicles (DAILY IVECO) fuelled with different CH4/H2 blends, measuring its emissions in terms of atmospheric pollutants and CO2, manteining the scientifical coordination of the project.


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3. PARTICIPANTS

Before giving the details of the partnership that had been constituted in order to fulfil the project objectives, it must be underlined that all the work had been constantly followed and supported by CESTEC SPA, a company belonging to the Lombardy Region. In particular, CESTEC SPA had coordinated the project administrative procedures, supporting the lead partner for its expenses declarations and strengthening the diffusion of REGINS and BONG-HY on a European Platform. Contacts of CESTEC SPA: Dr. Francesco Morabito, Dr. Vera Martinelli Lead Partner: Municipality of Brescia Responsable: Dr. Ettore Brunelli Other team members: Dr. Nunzio Pisano, Dr. Eng. Angelo Capretti, Dr. Nora Intenti

3.1. PRESENTATION OF THE MUNICIPALITY OF BRESCIA The Municipality of Brescia, located in the North-East of Italy, at about 90 km far from Milan, had always been active in the field of the environment safeguard. In this sense, the Municipality had always promoted initiatives concerning the monitoring and the protection of the air quality, the remediation of polluted sites as well as the sustainable urban mobility. With reference to this last topic, the Municipality of Brescia had started a project that concern the methanisation of both the urban buses and the private cars, the realisation of NG refuelling stations and the management of a program of development and diffusion of sustainable public vehicles. Partner: University of Linz-University of Applied Sciences Upper Austria Research & Development Responsible: Prof. Dieter Meissner Other team members:Dr. Gerhard Buchinger; Dr. Thomas Raab; Dr. Stefan Griesser

3.2. PRESENTATION OF THE UNIVERSITY OF APPLIED SCIENCES UPPER AUSTRIA RESEARCH & DEVELOPMENT

The University of Applied Sciences consists of four campuses located in the province of Upper Austria. Each campus has its own International Office, which lists relevant information for both international students and partner institutions. The campus in Wels is one of the four schools of the University of Applied Sciences, Upper Austria and provides vocational higher education in the fields of Engineering and Business Management. It had grown continuously since it opened in 1993. The reasons for this are the direct career-relevance of the degree programs and the high demand for this kind of graduates on the part of industry. The university is well- established as an education, training and research partner of the busy and varied manufacturing sector in Upper Austria and of organisations further afield. Partner: University of Esslingen, University of Applied Sciences Responsible: Prof. Renate Hiesgen Other team members:Dr. Jϋrgen Kraut, Dr. Jϋrgen Haiber, Dr. Bernd Jung 3.3 PRESENTATION OF THE UNIVERSITY OF APPLIED SCIENCES OF ESSLINGEN Universities of applied sciences represent a relatively recent but highly successful development in Germany's higher education. The University focuses on a more practically oriented method of education with individualized teaching in small groups and a highly structured curriculum. Research is also conducted at these institutions, although it is more


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directed towards practical requirements.The rising popularity of these institutions is reflected in the fact that today about 60 % of all engineers and business administration graduates come from universities of applied sciences. Another vital feature of the University of Applied Sciences is their emphasis on offering various services to the respective region. Their intensive connections to regional industry and public administrations help students to become familiar with the requirements of the working world. The University has different labs for SEM/XRD analysis and AFM analysis. These labs had been used for the experimentations foreseen by this project. Partner: Kompetenz und Innovationszentrum Brennstoffzelle der Region Stuttgart (KIBZ) Responsible: Dr. Bernhard Schaible

3.3. PRESENTATION OF THE KOMPETENZ UND INNOVATIONSZENTRUM BRENNSTOFFZELLE DER REGION STUTTGART (KIBZ)

The Kompetenz und Innovationszentrum Brennstoffzelle der Region Stuttgart (KIBZ) is a non-profit association financed by 46 members. It’s a network of professional competence in politics, economics, R&D institutes and associations. It’s a center and pivotal point for fuel cell technology and a platform for communication. Main objective of the Kompetenz und Innovationszentrum Brennstoffzelle der Region Stuttgart (KIBZ) is to utilise the innovative potential in the Region by networking :

- Cooperation; - Innovation (products, services, new enterprises); - Transferring know-how through informal knowledge and communication structures.

The Kompetenz und Innovationszentrum Brennstoffzelle der Region Stuttgart (KIBZ) even provides a worldwide representation of the Competence and Innovative Power of Enterprises in the Stuttgart Region. External expertise: ASM SPA Responsible: Dr. Eng. Agostino Braga Other team members: Dr. Eng. Renzo Capra, Dr. Eng. Paolo Rossetti

3.4. PRESENTATION OF ASM SPA

ASM SPA is the enterprise that operates in the energetic field in Brescia and that owns the cogenerative power plants of energy and heat production, the waste-to-energy plant of both urban and provincial wastes (which covers the 40% of the district heating of the city just by itself) and the water purification plants. It’s important to note that ASM SPA had always been in the van in the energetic field focusing much of its attention on the environment so that it had started the project of district heating and cogeneration since 1971 and the waste-to-energy plant since 1991. Since year 2003 the waste-to-energy plant had been implemented because of the construction of a third combustion line , entirely due to the biomasses’ combustion, generating electricity and heat with an almost null balance of atmospheric carbon dioxide emissions. In this context, stating that hydrogen is actually seen as the “sustainable” fuel of the future, ASM SPA might be interested in considering the introduction of this innovative energetic vector in the Brescia territory for both mobility applications and stationary applications for the cogeneration of electricity and heat.


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4. OBJECTIVES

The activities that had been undertaken since the beginning of Genuary 2006 concern the use of hydrogen/natural gas blends in Internal Combustion Engines and in Solide Oxide Fuel Cells for the application in industrial vehicles.The main goal had been the obtainment of the largest environmental benefits. The development, homologation and safety studies will help the creation of a new infrastructure where the synergism between natural gas and hydrogen could accelerate the penetration of new low impact vehicles. The results of both the studies and the experimentations had been widely diffused. The proposed project is an integrated one since all the partners had conducted parallel studies and experimentations on different but complementary topics in order to reach the final common objective; therefore, common studies and results had been shared with continuity between the partners of the different Regions. The results of both the studies and experimentations had been applied to the automotive sector. This study constitutes a first step for a wider program of utilisation of hydrogen/natural gas blends in industrial vehicles.

In the frame of the project an international workshop concerning the results of the theoretical studies had been organised on the 19th of June in Stuttgart (Germany) by one of the partners involved (the Centre of Research KIBZ). Another international workshop concerning the results of the Italian, Austrian and German experimentations had been organised in Brescia at the end of the project (November 2006). The project had fostered future partnerships between public and private bodies. A synergism is actually present both in Brescia (Italy) and in the German and Austrian Regions, especially thanks to the Universities involved in the different Countries who work on the research for technological development.


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5. PROJECT CHARACTERISTICS

5.1. PROJECT DURATION: Begin: 1st of January 2006, end 30th of November 2006

5.2. PROJECT METHODOLOGY The BONG-HY project had foreseen both theoretical and experimental ativities that can be summarised in 8 different workpackages. WP1. Simulation of the combustion of H2/NG blends and validation of the code. The simulation activities had constituted a support of the lab tests concerning the application of H2/NG blends in an internal combustion engine. Main objective of these studies had been the evaluation of the modifications that have to be introduced in the combustion process due to the use of H2/NG blends. After the first lab tests the model had been validated and finalised in order to reduce both the fuel consumption and the pollutant emissions. WP2. State of the art of the use of H2/NG blends and analysis of pro and cons of the introduction of an advanced fuel in ASM SPA fleet. A state of the art of the activities that had been already carried out worldwide had been necessary in order to have some initial information concerning the application of H2/NG blends in internal combustion engines (arisen problems, adopted solutions, …) WP3. Modification, test and optimisation of an ICE. Main objective had been the reduction of both the fuel consumption and the emissions of pollutants and CO2. The tests had been conducted on an industrial vehicle belonging to the Municipalised Multiutility of Brescia. The blends used had a hydrogen content of 10% and 15% by volume. ENEA (Italian National Research Centre for Environment, Energy and New Technologies) roller test bench had been used (maximum vehicle weight: 1200 kg, maximum simulated velocity: 160 km/h, maximum power: 150 kW). WP4. Study of the use of H2/NG blends in SOFCs and related tests. The use of SOFCs in industrial vehicles with CH4 is a very promising option for the future, at least for APU applications. This study had concerned the technical benefits due to the use of H2/CH4 blends instead of pure CH4. WP5. Analysis of the regulations for the use of H2/NG blends and homologation procedures for single vehicle prototypes fuelled by H2/CH4 blends. This part of the work had aimed at studying the regulations concerning the use of H2/NG blends in the automotive sector starting from the state of the art worldwide till the understanding of how specific regulations could be created in Italy. The study had foreseen the homologation procedures that have to be taken over in order to imagine an extension of the project having as objective the creation of a fleet of vehicles run by H2/NG blends.


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WP6. Interviews to different key players about barriers and constraints. This theoretical part of the project had aimed at understanding the biggest technical, ecological and economical barriers that can be encountered with the introduction of a potential new technology (the H2/NG blends) on the market. WP7. Lab tests on the components of the Austrian SOFC to study the ageing processes due to the use of the H2/NG blends. Different kinds of lab tests (SEM/XRD and AFM analysis) had been conducted on some particular components of the SOFC (the electrodes and their catalysts in particular) after the use of the H2/NG blends as a fuel. The interest in the microscopy analysis is due to the fact that it’s possible to evaluate for different components of the fuel cell their degradation factors in function of time. WP8. Diffusion of the results and preparation of new proposals. The diffusion of the results had mainly taken over through two different Conferences, one of them at the end of the first six months (in Stuttgart) and the other one in Brescia at the end of the project (November 2006). Some divulgative papers and articles on the newspapers had been written too in order to promote REGINS and BONG-HY in particular among both the general public and the technicians interested in this field. Since the experimental activity foreseen by the project had last just a few months , the Italian partners of the project will try to search for an extension of the activities beyond the term of the project itself, looking for parallel and/or successive call for proposals coming from the Lombardy Region or the EU.


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5.3. PARTNERSHIP The idea of the application of H2/NG blends in internal combustion engines had been developed among the Italian partner ( the Municipality of Brescia) and its external expertise (ASM SPA) with the support of the Catholic University of the Sacred Heart of Brescia (Dept. of Mathematics and Physics) and ENEA (Italian National Centre of Research for the Environment, Energy and New Technologies) who had started to make some theoretical considerations on this topic at least one year before the approval of the project itself. Looking for possible partners in the Regions involved in REGINS, the Austrian Region suggested to contact the University of Linz and so the Italian partner had come in contact with Prof. Dieter Meissner, who thought about the possibility to make a parallel study of the use of H2/NG blends in a SOFC produced in his labs for APU (auxiliary power unit) applications. At the time of the editing of the project, thinking about a potential partnership, Prof. Dieter Meissner (University of Linz) was working on his SOFCs with the collaboration of Prof. Renate Hiesgen (University of Esslingen) , and so the University of Esslingen entered the project too. Finally, the German Region had found a fourth partner in Stuttgart (the Centre of Research KIBZ) who wanted to join the project with a theoretical but still interesting activity having as objective the results of some interviews that would have underlined the barriers encountered by the H2/NG blends for their possible penetration on the market.

5.4. GANTT DIAGRAM OF THE PROJECT The following figure reports the GANTT DIAGRAM with the temporal scheme of the activities of the project. WPs ACTIVITY 01/01_06/30 07/01_11/30

WP1 Simulation of the combustion of H2/NG blends (I)

WP2 State of the art of the use of H2/NG blends (I)

WP3 Lab tests and optimisation of the ICE (I)

WP4 Study of the use of H2/NG blends in a SOFC and labtests (A)

WP5 Analysis of the regulations and the homologation process for the use of H2/NG blends (I)

WP6 Interviews to different keyplayers in order tounderstand how to overcome the technological and social barriers associated to the use of H2/NG blends (D)

WP7 Lab tests on the SOFC’s components in order toverify their degradation due to the use of H2/NG blends (D)

WP8 Diffusion of the results and preparation of newprojects


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5.5. FINANCIAL PLAN The financial plan of BONG-HY had foreseen the following division of the budget among the European partners: Total Budget € 251.192,53Total Budget Upper Austria (University of Linz) € 82.646,00Total Budget Baden-Württemberg (University of Esslingen) € 10.000,00Total Budget Baden-Württemberg (Centre of Research KIBZ) € 10.000,00Total Budget Lombardy Region (Municipality of Brescia) € 148.546,53

Since all the partners, with the exception of the Municipality of Brescia, had received just a cofinancing of 50% from the EU, the effective budgets received from the EU (and from the Lombardy Region and Ministry of Transports for the Italian partner) had been the following: Total Budget € 199.869,53Total Budget Upper Austria (University of Linz) € 41.323,00Total Budget Baden-Württemberg (University of Esslingen) € 5.000,00Total Budget Baden-Württemberg (Centre of Research KIBZ) € 5.000,00Total Budget Lombardy Region (Municipality of Brescia) € 148.546,53

The total budgets had been so distributed among the 3 phases of the project (Oct05_Dec05 - Jan06_Jun06 - Jul06_Nov06): Phases of the project Oct05_Dec05 Jan06_Jun06 Jul06_Nov06Total Budget € 3.800,00 € 97.941,00 (*) € 149.451,53(*) Total Budget Upper Austria

(University of Linz) € 0,00 € 50.611,00 (*) € 32.035,00 (*)Total Budget Baden-Württemberg

(University of Esslingen) € 0,00 € 4.530,00 (*) € 5.470,00 (*)Total Budget Baden-Württemberg

(Centre of Research KIBZ) € 0,00 € 10.000,00 (*) € 0,00Total Budget Lombardy Region

(Municipality of Brescia) € 3.800,00 € 32.800,00 € 111.946,53 (*) = the budgets indicated are cofinanced for the 50%


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6. PROJECT RESULTS

6.1 WP1 - SIMULATION OF THE COMBUSTION OF H2/NG BLENDS AND VALIDATION OF THE CODE 6.1.1 Introduction

The reduction of pollution represents a primary target of present and next years, especially as far as urban areas are concerned which are characterized by high pollutant species concentrations. However, a remarkable progress had been achieved during the last decades: since first steps had been made in the field of emission standard issuing (1966, in California), present time vehicles are characterized by 99% reduction of emissions due to the consistent evolution of internal combustion engine design, and particularly during last years. Nevertheless, generally speaking, the environmental problem is still far from being definitely solved: CO2 represents a fairly recent concern since Kyoto targets are hard to be achieved for almost each participating country. The introduction of H2 into the automotive field appears in this scenario as the only long-term solution to consistently reduce CO2 emissions on a global basis. Certainly, fuel cells are the ideal technology to entirely exploit H2 potential, but they are still undergoing research and development design stage to fix important issues such as material costs, durability and reliability. However, H2 may still be thought as a short-term solution if utilized into assessed technologies, such as natural-gas (NG) internal combustion engines. Recently, the H2/NG blends had also claimed more and more attention due to:

• Cheaper cost than traditional liquid fuels;

• Low carbon-based (CO,CO2) emissions due to low carbon content of the fuel;

• The possibility of getting particularly high efficiencies for the intrinsic high potential of the fuel in terms of resistance to detonation and flammability range.

Moreover, the use of NG blended with H2 may be a good solution since those blends are characterized by higher laminar flame speeds than pure NG [1,2], which in turn allows to get a more efficient combustion process (and then higher global efficiencies) and a reduction of CO2 emissions for the lower fuel carbon content. Advantages are even more relevant under partial load conditions if lean-burn control strategies are adopted since H2 addition extends the lean-limit of natural-gas [3,4] and reduces the penalties in terms of HC emissions [5,6]. The use of blends characterized by low H2 content (up to 20-30% vol.) does not require essential modifications of a given native NG engine: higher NOx emissions [7] are the drawback for the higher temperatures occurring during combustion. Two strategies may be adopted to overcome that problem:

• Delaying spark advance if engine is fuelled by stoichiometric mixtures;

• Lean burn operation.

The second solution is more favourable since it does not reduce engine output and gives lower CO2 emissions and fuel consumptions. However, tailpipe NOx emissions related to lean-burn operation are practically equal to raw NOx emissions for the unavailability of commercial DeNOx catalysts. Here we describe the role of numerical simulation to drive the implementation of interventions on engine control when NG is substituted by a 15% vol. H2 blend. The influence of control parameters (spark advance and λ) on engine performance in terms of instantaneous and average pressure, had been primarily investigated. In order to


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reach that aim a 3D numerical code had been setup and validated to describe the H2/NG blend behaviour, and special attention had been devoted to represent the combustion process which evidently constitutes the most interesting and challenging aspect in this context. The assessed CFM turbulent combustion model had been implemented into KIVA-3V code: it had been validated for H2/NG blends, and subsequently applied to the prediction of engine behaviour under varying operating conditions. Experimentally obtained results in terms of fuel consumption and emissions testify the validity of the proposed approach.

6.1.2 Modelling issues

Engine performance (e.g. instantaneous and average pressure) had been evaluated by means of a 3D model: actually, 3D models represent the most reliable solution in terms of predictivity, and allow to take into proper account the actual geometry of the combustion chamber. The 3D models are based on the resolution of thermal-fluid-dynamic equations (mass, species, momentum and energy, reported below), which in general represent the evolution of thermal-fluid-dynamic parameters over time and space:

0~

=∂

∂+

∂∂

α

αρρxu

t (1)

( )iiiii Yu

xmJ

xxY

utY ′′′′

∂∂

−+∂∂

−=∂∂

+∂

∂α

αα

ααα ρρρ &,

~~

~ (2)

( βαα

αβ

αβ

α

β

αβ

α

ρρτ

ρρ

uux

gxx

p

xuu

tu

′′′′∂∂

−+∂

∂+

∂∂

−

=∂∂

+∂

∂

)

~~~

(3)

( )Tux

cqmhtpJ

x

xTu

tTc

pr

n

0iiiT

p

′′′′∂∂

−−−∂

∂+

∂∂

−

=⎟⎟⎠

⎞⎜⎜⎝

⎛

∂∂

+∂∂

∑=

αα

αα

αα

ρ

ρρ

&,

~~

~

(4)

In this work the cited PDE equation set had been discretized and solved with the finite-volume KIVA-3V numerical code [8]. A turbulence model is also needed to close turbulent transport terms: k-ε RNG model had been used to that aim (k and ε equations omitted for the sake of brevity).


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Source terms in equations (2) and (4) (respectively im& and ∑=

n

0iiimh & ) govern chemical

reactions and heat release due to the occurrence of combustion process; as far as Spark Ignited (SI) engines are concerned, a strong coupling between turbulent phenomena and combustion chemistry occurs, and therefore modelling of those source terms requires a specific treatment. KIVA-3V original version had been therefore modified to improve its predictive capabilities, and to that aim CFM (Coherent Flame Model) combustion model had been implemented into that computational environment. Details are provided below.

6.1.3 Turbolent combustion modelling

CFM model had been first introduced by Marble and Broadwell [9], and later improved [10-12]. Its formulation is based on the hypothesis of flamelet combustion [13-15]. The generalized flamelet assumption requires that chemical reactions take place into thin sheets which propagate at the laminar flame speed: the mean reaction rate can then be expressed as :

Σ= LuFu SY ,ρω (5)

where uρ is the unburned density, the deficient reactant mass fraction, SuFY , L the laminar flame speed based on local thermo-chemical variables, and Σ the flame surface area per unit volume. In the mean reaction rate model two unknown parameters appear: SL and Σ . The former strictly depends on local thermochemical variables, while the latter can be described by a transport equation: its final form, which comes from several modelling closure hypothesis is the following:

⎟⎟⎠

⎞⎜⎜⎝

⎛Σ⋅∇⋅∇+

Σ−Σ=Σ⋅∇+

∂Σ∂

Σσν

ρβρ

α t

F

2Lu

YS

evt

(6)

The equation (6) contains production ( Σeα ) and destruction (F

2Lu

YS

ρβρ Σ

− ) terms, α

and β being constants respectively of the order 1 and 5, and e the mean strain rate. Since the flamelet assumption leads to a separation between flame and turbulent scales, all the chemical reactions can be summarized into the SL quantity, and this model can behave satisfactorily by keeping track of two species: the unburned and burned mixtures. As far as the energy source term in equation (4) is concerned, the turbulent reaction rate can be associated to a thermal one by taking into account enthalpies of formation which are related to the fuel Low Heating Value (LHV). The CFM model had been successfully applied to model combustion in SI engines [16-21]; the model gave so far significant results in terms of predictive reliability and accuracy.


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6.1.4 Laminar flame speed calculation details

Laminar flame speed of H2/NG blends had been evaluated as a function of H2 percentage, equivalence ratio, unburned temperature and pressure. In order to reach that aim, the 1D model of the premixed flame had been setup as a pre-processor of the full 3D model, to build-up laminar flame speed libraries. Equations of the laminar flame speed model are reported below:

cost=uρ (7)

0WhdxdT

dxd

dxdTuc

N

1kkkkp =+⎟

⎠⎞

⎜⎝⎛− ∑

=

ωλρ & (8)

( ) 0WVYdxd

dxdYu kkkk

k =−+ ωρρ & (9)

Where k varies from 1 to NS, NS being the total number of species,

represent species k chemical reaction rate summed over the total number of reactions N

∑=

=RN

1iikik qνω&

R and depends on the kinetic velocity of each chemical reaction qi:

[ ] [ ]∏∏==

−=S

ikS

ik

N

1jjri

N

1jjfii XkXkq ''' νν

(10)

where Xj represent the molar fractions of species j, and kfi and kri represent forward and backward reaction constants modelled via Arrhenius approach:

⎟⎠⎞

⎜⎝⎛−=

RTETAk iB

ifii exp (11)

ci

firi K

kk =

(12)

Ai,Bi, Ei are kinetic parameters and Kci the equilibrium constant of reaction i. The accuracy of laminar flame speed computation strictly depends on the utilised chemical mechanism: GRI 3.0 had been used in this context which consists of 325 reactions over which 53 species are involved [22]. A specific open-source chemistry solver (CANTERA) had been used to discretize and solve equations (7-9): it is characterized by high accuracy and computational efficiency [23].


16


6.1.5 Analysis of results

The whole experimental and numerical activities had been carried out in the context of a project involving ASM SpA (the energy multiutility of Brescia), the Catholic University of the Sacred Heart of Brescia, ENEA, the Universities of Roma “Tor Vergata”. A light-duty commercial vehicle originally designed for pure NG fuelling, and belonging to ASM fleet, had been studied by means of both numerical and experimental analysis: the main characteristics of the IVECO powertrain are reported below (Table 6.1).

Homogeneous

Displacement, cm3 2800

Bore X stroke, mm x mm

94.4 x 100

Compression ratio 12.2

Rated power 78 kW @ 3800 rpm

Max torque 220 Nm @ 2200 rpm

Emission standard EURO III

Tab. 6.1 : Daily engine parameters

The engine had been tested on a roller bench; experimental data had been acquired in terms of single cylinder pressure trace as a function of Crank Angle (CA) and main gaseous emissions (CO, HC, NOx, CO2). On one hand, pressure trace is in fact a fundamental information both on engine performance (via Mean Indicated Pressure), and on combustion process evolution: it is therefore the ideal interface between experimental and numerical data.Other information are needed to comply with regulations on pollutant emissions. Details on experimental test bench and acquisition systems are given in [24]. As previously reported, the main target of the whole joint project had consisted in using numerical simulation to address the main effects of a moderate addition of H2 (15% vol.) to NG, to pre-estimate the interventions on engine control parameters (such as electrical spark advance), to finally get a reduction in fuel consumption and CO2 emissions with no major drawbacks on NOx emissions. The engine combustion chamber (Fig 6.1) had then been discretized into about 80000 cells: that size guarantees results fairly independent on average cell size.


17


Fig. 6.1. : Engine computational grid

Numerical model had been first applied to the analysis of pure NG operation with respect to different operating conditions, to evaluate the capabilities of the tool. Therefore, pressure traces had been compared to experimentally acquired ones, as it is displayed in Fig. 6.2. Data refer to three regimes characterized by quite different operating conditions (rpm=1500, 2500, 3500 ; load=25 ,50%; spark advance=27; 28; 33 CA).

300 330 360 390 420 450 4800

5

10

15

20

25

30

35

40

45

50

numerical experimental

α = 0.94β = 5.0

Pres

sure

[bar

]

Crank [°CA]

(rpm=1500 - load=25% - sp.adv=27°) (rpm=2500 - load=50% - sp.adv=28°) (rpm=3500 - load=25% - sp.adv=33°)

Fig. 6.2 : Natural gas operation Pressure Traces

A satisfactory agreement may be observed between numerical and experimental pressure traces, so allowing to consider the model able to represent combustion process. It is further worth noting that the numerical model main constants α and β (eq.6) had been put equal to respectively 0.94 and 5.0, and they had been kept unchanged by varying engine operating conditions. This circumstance, that usually represents a hard issue for a turbulent combustion model, here testifies the good performance of the whole numerical tool in terms of predictive reliability. The numerical tool had then been applied to the analysis of 15% vol. H2/NG blends: this change in operating conditions first gives rise to a variation of laminar flame speed. Laminar flame speed is plotted in Figure 3 vs CA for both pure NG and H2/NG mixture (2500 rpm and 50% load operating conditions, stoichiometric mixtures). The evident increase of laminar flame speed in turn determines potentially higher heat release rate and then higher performance potential in terms of thermal efficiency.


18


340 360 380 400 4200,6

0,7

0,8

0,9

1,0

1,1

1,2

1,3

1,4

rpm 2500load 50% lambda = 1.0

Lam

inar

flam

e sp

eed

[m/s

]

Crank Angle [°]

(blend 15% vol H2) (pure NG)

Fig. 6.3 : Laminar flame speed vs CA for pure NG and 15% vol H2

(both operating conditions are stoichiometric)

300 330 360 390 420 450 4801

2

3

4

5

6

7

8

9

10

11

12

13

numerico sperimentale

BLEND85%ch4-15%h2

Pre

ssur

e [b

ar]

Crank Angle [°]

(rpm=3000 - load=20% - sp.adv=32°) (rpm=2000 - load=10% - sp.adv=32°)

Fig. 6.4 : Pressure trace vs CA (15% H2 mixtures)

The effect of H2 on engine performance had then been investigated: at first, light load conditions had been experimentally implemented to validate the code under the operation with blends: the comparison between experimental and numerically predicted data is reported in Fig. 6.4. It can be stated again that the numerical model performance are roughly unchanged, underlying that α and β constants had not been changed with respect to pure NG cases.


19


340 360 380 400 420

10

15

20

25

30

35

40

45

50

55

rpm=2500load=50%sp.adv=28°

Pre

ssur

e [b

ar]

Crank Angle [° CA]

(Blend 85NG-15H2) (Pure NG)

Fig. 6.5 : Pressure trace vs CA (15% H2 mixtures) : fixed operating conditions

Once the model capabilities had been accessed, the numerical tool had then been applied to predict engine performance in order to optimise the electrical spark advance. Actually, first observations had indicated, as expected, higher combustion speeds: this is confirmed in Fig. 6.5 where pressure traces are reported for pure NG and HCNG15 blend (all other operating parameters kept constant, including stoichiometric proportions). That behaviour of H2/NG blends may be at a first glance desirable for its high performance in terms of engine efficiency. However, that increase in efficiency is accompanied by an increase of NOx emissions, as it is evident by examining average temperature trend in Fig. 6.6 for both cases. That is a major drawback which must be instead controlled.

340 360 380 400 420600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2100


Aver

age

Tem

pera

ture

[K]

Crank Angle [°]

(pure NG) (85-15 NG/H2 blend)

Fig. 6.6 : Combustion chamber average temperature vs CA

(pure NG and 85-15 NG/H2 blends, stoichiometric proportions)


20


A set of operating conditions (Tab. 6.2) had been identified to be somewhat representative of the whole engine operating domain. Engine simulations had been performed to identify a related set of corrections to be applied to the engine control to approximately keep engine performance constant (in terms of average pressure) so that reducing NOx emissions to a value comparable to the original NG solution.

Operating Conditions Spark Advance Correction

rpm=1500; load=25% +2 rpm=1500; load 50% +4 rpm=2500; load=25% +2 rpm=2500; load=50% +4 rpm=3500; load=25% +3 rpm=3500; load=50% +4

Tab. 6.2 : Engine operating conditions and related spark advance corrections

It can be observed that a slight correction is required, in the range 2-4°, depending on load and rpm. Moreover, the observed superior performance of blends under lean-burn conditions in terms of flammability limit suggests the use of that strategy to control engine output. Pressure traces are reported in Fig. 6.7: the effect of Air Fuel Ratio (AFR) on engine performance is highlighted, and also reported in Fig. 6.8 in terms of average pressure during combustion process (CA interval: 310-480).

340 350 360 370 380 390 40015

20

25

30

35

40

45

50

55 rpm=2500load=50%sp.adv=28°

Pre

ssur

e [b

ar]

Crank Angle [°]

(NG) (blend stechio) (blend lambda1.1) (blend lambda1.2) (blend lambda1.3) (blend lambda1.4)

Fig. 6.7 : Numerical pressure trace vs CA (Hythane 15%vol.):

AFR effect on engine performance


21


6

6,5

7

7,5

8

8,5

9

9,5

10

pmi [310:480]

CH4

Blend lambda1.0Blend lambda1.1Blend lambda1.2Blend lambda1.3Blend lambda1.4

Fig. 6.8 : AFR effect on AMEP (Blend HCNG15)

Higher efficiency, that is typical of lean-burn combustion processes, had been also accompanied by a higher potential in terms of NOx reduction, due to the occurrence of lower temperatures into the combustion chamber. That effect on average temperature is plotted in Figure 9, while a sketch of 3D temperature fields at 380 CA is given in Fig. 6.10 and 6.11 for respectively stoichiometric and λ=1.4 operating conditions.

340 360 380 400 420600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2100


Aver

age

Tem

pera

ture

[K]

Crank Angle [°]

(pure NG) (blend stechio) (blend lambda 1.1) (blend lambda 1.2) (blend lambda 1.3) (blend lambda 1.4)

Fig. 6.9 : Average AFR effect on combustion chamber

.

Fig. 6.10 : Temperature in the chamber at 380 CA: stoichiometric AFR (λ=1.0).


22


Fig. 6.11 : Temperature in the chamber at 380 CA: (λ=1.4).

Once the corrections to the engine control system had been apported, vehicle performance had been experimentally verified as far as the urban part of ECE cycle is concerned. Results, reported in Fig. 6.12 for HCNG15 blends for both stoichiometric and lean operating conditions [24], evidently underline the success in getting consistent improvements as far as fuel consumption and CO2 emissions are concerned.

02468

10121416

lambda=1 lambda=1.4

%

Fuel cons.reductionCO2 em.reduction

Fig. 6.12 : NG/H2 blend (85-15%): experimental fuel consumption and CO2 reduction on the urban part of ECE cycle

0

0,2

0,4

0,6

0,8

1

1,2

Pure NG Blend 85NG-15H2lambda=1

Blend 85NG-15H2lambda=1.4

g/km

CO

HC

NOx

Fig. 6.13 : NG/H2 blend (85-15%): experimental fuel consumption and CO2 reduction on the urban part of ECE cycle


23


Tailpipe emissions (Fig. 6.13) represent the actual drawback of lean-burn operation: actually, in those conditions HCs had remarkably increased; NOx, which in lean-burn cases do not take advantage of the equipped Three Way Catalyst, had been limited to about the same value of the original solution not affecting the engine performance excessively.

6.1.6 Conclusions

The addition of a moderate content of H2 (up to 20-30% vol.) to NG may constitute an effective short-term solution to face with Green-House Gases problem and at the same time to introduce H2 in the fuel market without consistent changes on present time engine technology.

The activities that had been carried on in WP1 had mainly concerned the aspects of engine control to get optimal results in terms of CO2 emissions and fuel consumptions of a DAILY vehicle without compromising the original pure NG performance in terms of NOx emissions. The introduction of numerical simulation had been demonstrated to be effective in order to address engine parameter corrections to get the target.

Results mainly indicate that:

• The presented numerical code (KIVA-3V), characterized by the presence of a reliable turbulent combustion model (CFM), is capable of reproducing the engine performance in terms of pressure traces also by varying operating conditions with no further adjustment of combustion model tuning constants.

• The numerical code predictivity is substantially unchanged by fuelling pure NG or H2/NG 15% vol. blends.

• Numerical model results over a wide range of operating conditions suggested the interventions on spark advance to limit temperature in the combustion chamber and therefore NOx emissions.

• Lean burn engine control strategy may be a valuable solution to improve engine thermal efficiency and contemporarily limit temperature in the combustion chamber.

• Experimental tests obtained so far on the engine on a cycle basis (urban section of ECE cycle) had indicated a consistent reduction of both CO2 emissions and fuel consumption with no major penalties in terms of NOx emissions.


24


6.2 WP2 – State of the art of the use of H2/NG blends and analysis of the pro and cons of the introduction of an advanced fuel in ASM SPA fleet

6.2.1 Introduction As known, in a “volumetric” internal combustion engine a blend of air and fuel (gasoline, natural gas, hydrogen,…) is burnt in a cylinder. The energy that results from the combustion, thanks to the pression exerted on a mobile piston, is transferred to a power train becoming mechanical energy. For this project the potentialities and the critical aspects related to the use of a “mixed” fuel, the blends of hydrogen and natural gas with increasing percentages of hydrogen had been studied. These tests are ongoing in Malmo ( SWEDEN) on VOLVO urban buses, originally destinated to be diesel vehicles and successively modified in order to be fuelled by both pure natural gas and blends of natural gas and hydrogen. From the chemico-physical comparison of the two fuels, it emerges that the hydrogen flame speed is much higher than methane’s , as well as the adiabatic flame temperature. In the following table the values can be compared for the two fuels:

FUEL FLAME SPEED

(m/s) FLAME TEMPERATURE

(°C) Methane 0,4 1875 Hydrogen 2,65 2045

Tab. 6.3

With reference to the use of a blend of hydrogen and natural gas in a traditional internal combustion engine, a higher flame speed with respect to methane allows to increase the air/fuel ratio ( usually indicated with the letter λ) beyond the cut off limit of pure methane, maintaining the conditions for a stable combustion. For λ values higher than those ones usually used for pure methane and thanks to a higher hydrogen flame speed with respect to methane, the internal combustion engine efficiency increases and it is possible to reduce the most important urban pollutants emissions significantly, among which the nitric oxides (NOx), the non methanic hydrocarbons (NMHC) and the carbon monoxide (CO) [25]. Concerning the nitric oxides, the hydrogen flame temperature, 200 °C higher than methane’s, could bring to higher emissions, since the combustion of pure hydrogen would happen at a higher temperature with respect to methane. Nevertheless, if hydrogen is present in a blend mixed with methane, letting more air entering the combustion chamber with respect to the one foreseen stoichiometrically, the flame temperature decreases and so the problem can be overcome. Under any operative condition, just those blends of air and methane that belong to the flammability range will permit the flame propagation from an adequate ignition source. The flammability range of methane in air is much more restricted with respect to other traditional fuels. On the contrary, the wide flammability range of the blends hydrogen-air permits a relevant increase of the flammability range in a stationary tubular flux for every flux velocity. The simultaneous use of methane and hydrogen in internal combustion engines not only allows to work with leaner blends and with faster fluxes, but permits to reduce the cyclic variations too. Actually, the adding of hydrogen in methane permits to accelerate the


25


initial speed of the propagation of the flames through the whole range of blends used as fuels, even for those ones that flow very rapidly. This increase of the initial speed and of successive flame propagation reduces the ignition time and the combustion period of the internal combustion engines; consequently, there are significant increases both in the combustion process and in the engine functionality. A typical european example of tests of blends of methane and hydrogen is ongoing in Sweden, taken over by the SIDKRAFT, for hydrogen percentages of 8% and 25% [26]. The tests are conducted on TG103/G10A urban buses engines that originally were turbodiesel engines, replanned by VOLVO in order to be fuelled by methane. The evaluation of the functionality of these engines in terms of efficiencies and emissions reduction had been very interesting. In particular, different test campaigns had been taken over for blends with variable air/fuel ratios between λ = 1.0 and λ = 1.8 and different cranck angles. The cranck angles range that had been chosen varies from the optimal angle condition equivalent to the condition of maximum best torque (MBT) and the angle relative to the stability condition limit. From the following figures it is possible to note that, once stated the value λ = 1.7, with respect to different cranck angles the combustion of a blend with a hydrogen content of 24,8% in volume is faster than the one for pure methane. With regard to the efficiencies, for the less lean blends the difference with pure methane is negligible while it becomes relevant for λ values higher than 1.4. The maximum efficiency is associated with the maximum best torque condition (MBT) and decreases with a delayed ignition. As can be seen from Fig. 6.15, the maximum efficiency corresponds to λ = 1.7.

Fig. 6.14 : HC and NOX emissions Fig 6.15 : Engine efficiency with pure Methane and blends Concerning the emissions, for lean blends there is a decrease of nitric oxides with a correspondent increase of hydrocarbons. The decrease of nitric oxides is due to the presence of an air quantity higher than the stoichiometric one, while the increase of hydrocarbons is due to combustion conditions less stable with respect to the increase of the λ value.


26


In Fig. 6.14 the results of the Swedish tests that illustrate the nitric oxides emissions in function of the hydrocarbons emissions with a variable λ had been reported. Considering the maximum efficiency condition of the internal combustion engine, the hydrocarbons emissions, for fixed nitric oxides emissions, decrease by 1-2 g/kWh7(see Fig. 2.3). 6.2.2 Infrastructures needed for the refuelling of blends of hydrogen and natural gas vehicles The infrastructures for the refuelling of blends of hydrogen and natural gas vehicles consist of a refuelling station reachable by the natural gas grid with the local presence of hydrogen too. Hydrogen can be produced on site or it can arrive through a dedicated pipeline. The site of the waste to energy plant of Brescia is ideal for the localisation of such a refuelling station since in its vicinities a refuelling station for industrial vehicles fuelled with pure natural gas exists and hydrogen could then be produced on site by electrolysis done with off-peak electric energy coming from the third line of the waste to energy plant or by a small capacity gasifier ( about 100 kg/h for maize refuses and about 200 kg/h on average for other fuels).

Fig. 6.1.6 – Refuelling station for vehicles fuelled by blends of hydrogen and natural gas [27].

From Fig. 6.16 it can be seen that the white column can be set in order to take out the natural gas from the tank on the left and mix it with hydrogen (in different percentages by volume) before refuelling a vehicle.


27


6.2.3 The duty cycle of the urban waste collecting vehicles The vehicle that collects and compacts the urban wastes represents a very pollutant vehicle category, whose emissions exceeds even those ones of urban buses because, even if they almost travel along the same streets, they are characterised by an inferior number of stops and by speeds on average higher. Concerning the city of Brescia, an ongoing methanisation process involving both vehicle categories is taken over by the Municipality of Brescia and ASM SPA. Another decrease in atmospheric emissions of these vehicles can be due to the use of blends of hydrogen and natural gas with an increasing content in hydrogen by volume. We can consider different indicators whose values are representatives of the attention that must be paid to this vehicles in order to reduce their atmospheric emissions, even if they are not used for the public transport. Here under we consider some Figures that illustrate both the velocity trend of these vehicles in function of their characteristic duty cycle and the specific power developed by the engine for the wastes compactness and for the movement of the lift arm for their collection. .

Fig. 6.17: Duty cycle of a waste collecting vehicle [28]. Looking at Fig. 6.17, on an 8-hour duty cycle the waste collecting vehicle rarely exceeds the speed of 50 km/h (only out of the city centre) and on average it has a speed between 20 and 40 km/h. Concerning the average speed of a waste collecting vehicle of ASM SPA fleet, it is around 9 km/h on an average daily route of 40 km. This means that about 60 waste bins are emptied on average every day and so the vehicle has to stop frequently, not reaching high speeds apart from the streets from the city centre to the waste to energy plant where the wastes are burnt. It’s even interesting to analyse the powers developed in the phases of waste collecting/unloading. The development of a power between 10% and 40% of the nominal maximum power of the vehicle (equal to 100 kW) during the routine operations (even when it stays still) leads to pollutants emissions in the atmosphere that exceeds the emissions of a vehicle or a bus on the same urban route. Actually, the power developed by the engine is proportional to the pollutant emissions in the atmosphere.


28


6.2.4 Characterisation of the atmospheric emissions and greenhouse gases thanks to the use of blends in function of the percentage of hydrogen (by volume) in the fuel The evaluations are estimated starting from the data contained in the “GREENING” study of The Centre of Research of the Environment and the Sustainable Development of Lombardy (CRASL) [29]. In 2003 the total number of km done by the whole fleet of waste collecting vehicles (constituted by 81 vehicles) has been equal to 2.377.212 km/y, with an average methane consumption of 71 kg every 100 km ( equal to about 100 Nm3/CH4/100 km). Concerning the estimation of the emission factors of the waste collecting vehicles, the elaborations had been based on the results of a study conducted for the Region Emilia Romagna (Alberici and Florio, 2003) starting from measurements in a test lab, the emission factors for the different pollutants of two waste collecting vehicles on two different duty cycles.. The results, along with the use of the emission factors elaborated for a study of ASM SPA, are summarised in Tab. 6.4.

Tab. 6.4 : Emissions of the waste collecting vehicles fuelled by diesel and NG Using these factors the emissions that would have been generated by the whole waste collecting vehicles fleet if fuelled by natural gas are estimated, so as it is possible to have a reference point for the successive evaluations of the variation of the pollutants quantity that follows the use of blends of hydrogen and natural gas.

Total emissions of 2003

NOx 11.410 SO2 0 CO 8.915 COV 1.973 PTS 475 PM10 332 PM2,5 237 CO2 4.668.844

Tab. 6.5 : Pollutant emissions for the year 2003 ( tonn)


29


Since there aren’t any measures of applications of blends of hydrogen and natural gas on waste collecting vehicles we can evaluate some theoretical emission values on the basis of experimental results obtained from Sydkraft for the Malmo buses. Before doing this extrapolation we need to fix some conservative hyphotesis. The experimental results are available for blends with a hydrogen content of 8% by volume for their use on real cycles, while the data relative to a blend of 25% by volume are available just for the engine tests, in specific functioning points. The available data show an increase of the engine performance with the increase of the hydrogen quantity in the blend. The benefits due to the introduction of the blends had been evaluated taking as a reference the emission data of the Malmo buses (with a hydrogen content of the 8% by volume) and the same emissions reduction and efficiency’s increase for a hyphotetic waste collecting vehicle fuelled by a blend of hydrogen and natural gas with a hydrogen content of 30% by volume (conservative hyphotesis). Concerning the reduction of the CO2 due to the use of a blend with respect to the use of pure methane it had been stated that the reduction is due both to an inferior carbon content in the fuel and the efficiency increase (that foresees less fuel consumptions).

31.2%

35 %

31.2%

35 %

4.2

5.9

2.93.5

Funzionamento non stabile

4.2

5.9

2.93.5

Funzionamento non stabile

Fig. 6.18 : Efficiency increase of the engine fuelled by the blend with respect to the

one using pure methane [30].


30


From Fig. 6.18 an efficiency increase (due to the use of a blend with an 8% hydrogen content by volume) from 31,2% till 35% for a λ value of 1.61 is illustrated. For inferior values of λ the efficiency is higher; nevertheless, since the first objective of the use of blends is the reduction of atmospheric emissions of the urban pollutants the experimentation have to optimise the combustion trying to obtain the maximum possible reduction of total hydrocarbons (HC), nitric oxides (NOx) and carbon monoxide (CO). From Fig. 6.18 it emerges that for λ = 1.61 there is a reduction of all the pollutants passing from the use of pure methane to the use of a blend with a hydrogen content of 8% by volume, with the exception of the nitric oxides whose emissions remain equal: nevertheless, for the blends of hydrogen and natural gas the combustion remains stable even for air/fuel ratios values that exceed those ones relative to natural gas, equal to 1.6, overwhich the combustion becomes instable. As a consequence, Fig. 6.18 reports the comparison between the atmospheric emissions values due to the use of pure methane with respect to those ones due to the use of a blend with a hydrogen content of 8% by volume till values of λ that foresee a still stable combustion for both fuels. Considering mainly the atmospheric emissions of the annual pollutants of the whole waste collecting vehicles fleet owned by ASM SPA of Brescia, on the basis of the number of km yearly done by these vehicles, their values are reported in the following table:

Actual fleet

Future natural gas fleet

HCNG30

∆CNG

∆actual

HC

4,74

1,97

1,40

-28,9 %

-70,5 %

NOX

46,38

11,34

6,80

-40 % (*)

-85,3 %

CO

10,05

8,91

7,38

-17,1%

-26,6 %

(*) thanks to the possibility of using high λ values in stable conditions (air excess) with diminishing Tcomb, ( possible thanks to hydrogen properties) the NOx emissions decrease of the 40% (Cromwell et al., 2002;Collier, 2004; Karner e Francfort, 2003)

Tab.6.6: Emissions (tonn/y) It’s interesting to observe that a similar experimentation can lead to a significative reduction of the pollutants emissions not only with respect to the traditional fleet of diesel vehicles but even with respect to the fleet converted to methane. Actually, the reductions foreseen are about the 30% for the hydrocarbons (HC), about the 20% for the carbon monoxide (CO) and about the 40% for the nitric oxides (NOx) , once the λ value had been optimised to a very lean blend that can guarantee a good combustion efficiency. Concerning the emissions reduction of carbon dioxide by the waste collecting vehicles fuelled by blends of hydrogen and natural gas with a hydrogen content of hydrogen equal to the 30% by volume, it’s due to two fundamental contributes:

1) the efficiency increase of the internal combustion engine in the shift from the use of pure methane to the use of blends (that takes to less fuel consumptions);

2) the inferior carbon content in the fuel (since hydrogen is absolutely carbon free).


31


Here following the table with the carbon dioxide emissions of the future fleet of waste collecting vehicles fuelled by methane and of a possible fleet fuelled by blends of hydrogen and methane with a hydrogen content of the 30% by volume is reported:

Future natural gas fleet HCNG30 ∆CNG

CO2 (t/y)

4668,8

3745

-19,8%

Tab. 6.7 : Carbon Dioxide Emissions ( tonn//y)

It’s then possibile to separate the two different contributions for the carbon dioxide reduction emission cited above at points 1) and 2) and report them in the following table:

Contributions to CO2 reduction HCNG30

Better ICE efficiency

507.7 t/y

H2 in the fuel

416.1 t/y

TOTAL

923.8 t/y

Tab. 6.8 : Contributions for the CO2 reduction due to the use of blends

It’s interesting to underline at this point that the CO2 emissions due to CH4 combustion (about 205 kgCO2/MWhCH4) for hydrogen production from natural gas, considering a reformer efficiency of the 80%, amount at about 610 t/y. Consequently, considering the CO2 tonnes avoided every year due to the use of blends in the waste collecting vehicles fleet of Brescia (see Tab. 6.5) it emerges that , even if hydrogen is produced by methane reforming, there is a net gain of CO2 emissions, of about 314 t/y even if releasing all the CO2 produced in the hydrogen production process in the atmosphere. With respect to the CO2 emission value reported in Tab. 6.4 a net gain of the 6,7% can be reached with the hypothesis of producing hydrogen from natural gas to fuel with the blends the whole fleet of waste collecting vehicles. Summarising:

H2 production by SMR CO2 emissions

CO2 emissions produced by the SMR process

610 t/y

Avoided CO2 emissions due to the use of HCNG30 314 t/y % reduction of CO2 emissions with respect to the CH4 fleet 6,7%

Tab. 6.9


32


From a technological point of view, we have many examples of experimentations of H2/NG blends in all the world and the informations coming out from these tests are very promising (with little investments we could have great benefits from the point of view of both efficiency and enviromental emissions). Examples of the applications of H2/NG blends had been studied both for the urban buses in Malmo, United States and Peijing and for road vehicles (principally in the United States) with a fuel combustion with higher air-fuel ratios than the ones associated to the combustion of pure natural gas. Ultra-lean combustion is an effective way to reduce harmful exhaust emissions and fuel consumption. But, as homogeneous charge engines operate leaner, it becomes increasingly difficult to ignite the mixture in the cylinder and the stability of the initial flame kernel deteriorates as well. The purpose of adding hydrogen to conventional fuels is to extend the lean limit of combustion because hydrogen can significantly improve flame stability and can allow a combustion at a lower temperature. Hydrogen-enriched combustion had been studied by several institutions and companies over the last three decades. To date, vehicles fuelled by natural gas blended with hydrogen had undergone road testing in California, Colorado, Pennsylvania, Sweden, claiming emissions reductions over the baseline of natural gas. First experiences with vehicles were carried on in the framework of a programme financed by DOE and NREL, in Colorado, the "Denver Hythane Project”, from 1991 to 1993, whose results are shown in the table below: NMHC (gr/mi) CO (gr/mi) NOx (gr/mi) Natural gas 0.01 2.96 0.9 Gasoline 0.59 14.1 2.2 Hythane 0.01 0.7 0.2 ULEV 0.04 1.7 0.2

Tab. 6.10 In the same years, limited activities were carried on by the University of Pisa and ENEA, with the following interesting results:

0.93

0.85

0.78

0.70

0.63

rapporto equivalente

36%20%

0%

H2 in volume

0.000.501.001.502.002.503.00

3.50

4.00

NOx,gr/HPh

Fig. 6.19

4.50


33


In a next phase, according to an exhaustive review by R. Sierens and E. Rosseel, by University of Gent, Belgium that relates to laboratory testings in the second half of 90’, many

2 blends (with 28 percent H2 : NOx = 28 ppm or 0.21 g/bhph and with 36

single cylinder Onan engine; 0.49 l,

imLesim al. (19 e e ignRw

f natural gas, e BMEP advantage

haust emissions of CO, NO,

t result in a significant increase in BHP. At the

lso a number of fleet tests had been carried on.

other experiences are recorded: « Hoekstra et al. (1994, 1995) examined a V8 Chevrolet 350 engine at one particular speed (12.7 kW, 1700 rpm, r = 9:1) with different hydrogen enriched compressed natural gas mixtures (0, 11, 20, 28, 36 percent H2) to simulate a light-duty truck travelling along a level paved road at 55 mph. They found extremely low NOx values at λ =1.6 (φ = 0.625) for the 28 and 36 percent Hpercent H2 : NOx = 12 ppm or 0.10 g/bhph). Hoekstra et al. (1996) described test results concerning the NOx emissions and the efficiencies of two engines. They concluded that with a 30 percent hydrogen–70 percent natural gas mixture the NOx levels can be less than 10 ppm, with negligible efficiency penalty relative to MBT spark timing: the first engine (the same as described above running at the same speed) operated at λ =1.54 (φ = 0.65); for the second engine (tests at Sandia National Laboratory on ar = 14:1) the air-fuel ratio λ was increased to 1.9 (or the equivalence ratio φ diminished to 0.52) to obtain this low NOx level. Swain et al. (1993) and Yusuf et al. (1997) made tests with a 20 percent hydrogen–80 percent natural gas blend on two engines (2 l Nissan and 1.6 l Toyota) under light load conditions. The increase in flame front propagation speed by H2 enrichment was measured (up to 29 percent), with a lean limit of combustion for the blend at λ =1.85 (λ = 1.56 for pure methane). For blended fuel, a 10 to 14 percent

provement in the brake thermal efficiencies over methane was found. arsen and Wallace (1997) and Cattelan and Wallace (1994) tested a turbocharged 3.1 l V6 ngine under mid and high load conditions with a 15 percent H2 hythane blend and found

ilar trends (for the exhaust concentrations in ppm) as the light load tests by Swain et 93) and Yusuf et al. (1997). It was clearly demonstrated that hythane reduces th

xhaust concentrations of regulated pollutants and increases the efficiency of a sparkition engine.

aman et al. (1994) described lean burn and stoichiometric combustion tests with a three-ay catalyst. The latter under steady state and transient conditions. For the lean burn (5.7 l

GM V8) engine it was again shown that hydrogen extends the lean limit othereby enabling lower NOx emissions without excessive THC. When thof hythane is sacrified by retarding the spark advance until methane and hythane produce equal BMEP the NOx concentrations drop significantly. Bell and Gupta (1997) described tests with lean mixtures of natural gas blended with 5, 10, and 15 percent hydrogen on a 4 cylinder 2.5 l GM engine at 2200 rpm and 50 percent WOT. Engine performance parameters, heat release analyses and exand HC were presented. Again the subject of the research was to extend the lean operating limit of the engine and to investigate the performance and emissions characteristics of the SI engine at these conditions. In the air-fuel ratio range 1.11 to 1.33 (equivalence ratio range of

0.75 to 0.90) the hydrogen addition did nonatural gas lean operating limit λ =1.56 (φ = 0.64) hydrogen addition allowed an increase in power (up to 47 percent again with 15 percent H2) due to an increase in the average flame

speed maintaining a sufficient heat release rate for good combustion quality. The lean operating limit (15 percent H2) was reached around λ = 2.38 (φ = 0.42). Brake thermal

efficiencies (15 percent H2) were higher than for the other fuelling cases at corresponding equivalence ratios. A maximum BTE of 37 percent was found at λ = 1.54 (φ = 0.65) and

at λ= 1.89 (φ = 0.53), an equal value compared to the use of pure natural gas at φ =1. With the addition of H2 and the extension of the lean limit, a minimum value of 0.11 g/bhph was

obtained for NOx over a relatively broad range of equivalence ratio.» [31-38]. During the last years, aA blend with the 20% of hydrogen and 80% of methane, called Hythane® thanks to its inventor Frank Lynch, Hydrogen Components, Inc.(HCI), had been found to lower compressed natural gas’ (CNG’s) NOx emissions by up to 43% in two buses. The recent


34


Hythane® bus demonstration project at Sunline transit in California used a 7% hydrogen by energy and the NOx emissions had been reduced by the 50%. Based on success with Hythane® buses, and the cost-effectiveness of Hythane® compared to available fuel cell technology, a number of projects are currently carried on all around the world, like the Beijing Hythane Bus Projet, whose demonstration phase will be to adapt 30 natural gas engines for Hythane operation. Collier Technologies Inc.(CTI) had licensed HCNG technology used for what had been designated the “City Engine,” a Daewoo natural gas engine modified specifically for transit buses and other heavy-duty transportation applications. The 11 L, six-cylinder, inline engine

ns on a mixture of 30% (by volume) hydrogen and 70% natural gas. CTI said that the h y

ery low 0.08 to 0.14 /hp-hr emissions of nitrogen oxides across a wide operating range (800 to 2200 rpm), well

r standard for heavy-duty engines that had gone into effect in had also been quite low — less than 1.57 g/hp-hr CO and 1.70 g/hp-

r total hydrocarbons.

e, probably due to faster combustion which increases the effective

or heavy-duty hydrogen internal combustion engines are

stability and allows a

of vehicles and for the sensible contribution to the degradation of air quality in urban

O2 emissions. The European Union committed to the goal

as required by the Kyoto Protocol.

ruengine ad already demonstrated that it can meet 2007 emission requirements today busing HCNG technology. The most significant result had been the vgbelow the 0.2 g/hp-h

007.Other emissions 2hAdditionally, CO2 emissions had been reduced not only as a result of the substitution of CNG by hydrogen. The special properties of hydrogen as a combustion stimulant can produce leverage factors much greater than 1 by improving fossil fuels--not just displacing them. For example, in Sweden, operation with hythane (24.8% vol. hydrogen) and natural gas had been compared for a heavy-duty natural gas engine and the study reveals a small increase in efficiency with hythanexpansion ratio which allows more work to be extracted. Therefore, if neither fuel cell buses nyet commercially available, the bridge technology appears to be a blended fuel of hydrogen and CNG that lowers natural gas’ emissions and creates a ready-market for renewable hydrogen. WP3 - Modification, test and optimisation of an ICE 6.3.1 Introduction Hydrogen-enriched combustion had been studied by several institutions and companies over the last three decades. The purpose of adding hydrogen to conventional fuels is to extend the lean limit of combustion because hydrogen improves flame lower temperature combustion. Even with stoichiometric mixture, HCNG advantages had been demonstrated, since blends determine a reduction of noxious emissions. In the framework of BONG-HY, bench tests with HCNG on a natural gas vehicle had been carried on in the ENEA labs. The results had showed a fair improvement of the engine efficiency and a reduction of both CO2 and local pollutants emissions. The growing sector of transports rises a big alarm either for the day-by-day increasing number areas, as well as for the global pollution. In Italy, with beyond 35 million of circulating vehicles, the consumption of primary energy, all coming from fossil sources, accounts for more than 30%, which roughly leads to a corresponding 30% increase in Cof reducing its dependence on imported fossil fuels (oil, natural gas, coal), by using at least 20% of alternative fuels within the year 2020; the corresponding commitment in the reduction of Greenhouse Gases (GHG) is the well-known 8% with respect to 1990 by 2012,


35


In Europe the sector of transports is responsible for the 25% of CO2 emissions, 40% of which is related to the vehicles circulating in urban areas. External costs due to th

e egradation of air quality related to transports had been estimated in about 11.7% of EU DP, cohose alarming data have to be added to the contribution to the total emissions from the

energetic sector (carbon dioxide, natural gas, nitrogen oxides, sulphur, aromatic compounds,….), which amounts to about 50% of the total contribution. Deaths caused by the smog, due to particulates and other emissions, are about 8000 per year just for Italy; on the other side, the global change becomes a “real” problem, with an increasing concern about GHG emissions. Nowadays a last-generation Euro4 car emits slightly less than 150 grCO2/km, with scarce perspectives to be able to reduce, with fossil fuels, that value very mu . It had been worldwide stated that the introduction of hydrogen as a “new” fuel could

inable energy system in the long term (2050 and eyond); according to this vision, emissions of both global and local pollutants will be

maintained under “safe” values. Even if the transition towards a hydrogen-based economy will be surely very long, its sustainability is achievable since now, also considering the limitations in the substitution of conventional fuels with less pollutant ones, less polluting. Furthermore, the contribution of

e introduction of biomass-derived fuels, for a limited quota of total consumption, is

Fig. 6.20

decades, it has been agreed

hydrogen as an energy carrier seems to be a real contribution to that goal, making possible, in the long term, the realization of a cleaner World.

dG rresponding to an outstanding value of 360 €/year per citizen. T

ch

contribute to the realization of a sustab

thcounterbalanced by the still growing demand of vehicles in the world ( see Fig. 6.20) [39].

Even if it’s difficult to forecast the future concerning the next worldwide that climate change is closely connected with GHG emissions, so we may ask for some important decisions for the beyond-Kyoto years. The stabilization of CO2 concentration at values not higher than 550 ppm (today’s value is 380 ppm) requires a strong emissions reduction: some of the IPCC scenarios aiming at that values shows a required decrease of GHG of 40-60% with respect to 1990, which means a “real” reduction of 70-90% of the emissions with respect to the “business-as-usual” forecast. Such a reduction won’t ever be achieved by using any actual available sustainable technology. Nevertheless, a “cultural shift” will be necessary, in order to reach that goal: the introduction of


36


6.3.2 Methane – hydrogen mixtures

A good opportunity in the short term can be represented by the utilization of blends of hydrogen with other fuels, first of all with natural gas (HCNG). When used ount of

y o fuels.

Methane ha

of the addition of h a wide rang

• •

V per Nm3, depending on the hydrogen content. Therefore, a natural gas engine, when fuelled with HCNG, shows a lower power output, while maintaining its best efficiency.

in an Internal Combustion Engine (ICE), even the addition of a small amhydrogen to natural gas (5-30% by volume, that means ~1.5-10% by energy) leads to manadvantages, because of some particular physical and chemical properties of the tw

s a slow flame speed while hydrogen has a flame speed about eight timeshigher; when the air/fuel ratio (lambda) is much higher than for the stoichiometric condition the combustion of methane is not as stable as with HCNG. As a consequence

ydrogen to natural gas an overall better combustion had been verified, even ine of operating conditions (lambda, compression ratio, etc.), finding the following

main benefits:

a higher efficiency lower emissions

Because of the characteristics of hydrogen, HCNG, despite its higher LHV per kg, has a lower LH

LHV (MJ/kg) LHV (MJ/m3)60

30

40

LHV

10

20

0

50

0 10 20 30 40% volume H2

Fig. 6.21

In case of turbocharged engines, power output can be increased again by a simple increase of the charging pressure, even possible because of the higher reluctance to detonation of hydrogen. Additionally, CO2 emissions had been reduced not only as a result of the substitution of CNG by hydrogen. The special properties of hydrogen as a combustion stimulant can produce leverage factors much greater than 1 by improving fossil fuels--not just displacing

em. Hydrogen leverage is defined as the following ratio : (% Emissions Reduction)/(% Energy Supplied as Hydroge

he increased efficiency makes this value higher than 1. An obvious benefit of the leverage effect is that a CO2 redu v ced by natural gas without any “sequestration” of CO

thn).

Tction is possible e en if the necessary hydrogen is produ

2.


37


6.3.3 Experimental se

As had been anticipated the fr terreg IIIC project called BONG-HY (parallel app lends Hydrogen in internal combustion engines and fuel cells) bench tes natural gas vehicle had been carried on in one lab of the Casacci h Center . The main Italian partners involved in the project had been the Municipality of Bre partner), ASM SPA (the energy

ultiutility of Brescia), the Catholic University of Brescia , the Universities of Rome “Tor

Displaced volume 2800 cm3

t up

previously, in amework of an EU Inlication of B Of Natural Gas and

ts on aa Reasearc of ENEA

scia (lead mVergata” and ENEA. The light duty commercial vehicle under test had been a Daily belonging to the ASM fleet, that had been mainly modified in the control system (ECU) for the test. Its engine was a 2.8 L NG fuelled, manufactured by IVECO (see Tab. 6.10 for specifications).

Tab. 6.10 Engine specifications

Compression ratio

12.2

Bore 94.4 mm Stroke 100 mm Rated power 78 kW @ 3800 Rpm Max Torque 220 Nm @ 2200

Rpm Emission Euro III Standard

The roller bench comes from APICOM; its control system had been recently upgraded by

dopted for the characterisation had been the urban part of NEDC Assing. The cycle a(repeated at least 20 times) and the value for the vehicle mass had been set to 3500 kg; therefore, the tests had been more severe than the homologation one. Therefore, the results are not directly comparable with OEM data, but surely more significative for the guide cycle of the ASM vehicles that could use these blends in the future (waste collecting vehicles).

Engine ECU Tuning tool

The tool used to modify the engine maps is called RACE2000, elaborated by Dimensione port. This software is able to transform data contained in the original eprom in easily odificable electronic mapping. Along with the software cited above, the MET16 simulator,

neously, tained thanks to the

EMP21 EPROM progra 6.3.4 Measurement system Cylinder pressure

Smable to modify the spark advance, the injection time and other parameters instantahad been used too. The programming of the final EPROM had been ob

mmer produced by Needham’s Electronics.

ad been equipped with a piezo-electric pressureand signals had been processed by been measured with an inductive crank-angle calculator

for on-line indicating measurements. The equipment had been manufcted by a Yokogawa DL 716 digital scope. In th

A single cylinder head h transducer hosted on a special spark plug a twochannel amplyfier while the angular position had module

actured by AVL, all data had been colle e picture below, an example (1500 r.p.m., 50 % at medium loads) of preliminary testing with pure methane is given, for the engine model validation.


38


Fig. 6.22

Emissions

Emissions ated system. This is composed by a MEXA-1170HNDIR (Dispersive Infra-red Detectors) that measures in real me CO, CO2 and HC and by a MESA chnology), for the evaluation of itric oxides concentrations and air-fuel-ratio (AFR); furthermore, a heated flowmeter (pitot

sampling probe permits to calculate the mass ( see Fig. 6.23).

Fig. 6.23

Fuel Consumption

had been measured using a HORIBA OBS-1300 integr

tin

-720NOx (ZrO2 te

type) mounted on the

Two blends had been tested, characterised by 10% and 15% in hydrogen by volume (HCNG10 and HCNG15) and used as a f urban part” of the ECE-15 driving cycle. Pure methane of certified composition and certified mixtures had been used for the tests.

linders had been used. To assure the requested ption measures, the cylinders had been weighed

efore and after drive tests (ECE 15) on the roller bench after a significative time (at least 20 cycles)

uel for the “

For the characterization tests, single cyrecision with regard to energy consump

b


39



40

Fig. 6.24

6.3.5 Tests on ENEA roller bench The main parameters that had been investigated are lambda (with vari

0

100

200

300

-8 -6 -4 -2 0 2 4 6Advance variation degree

500

520

540

560

400

500

600

700

800

900

NO

x pp

m

580

600

620

640

660

680

700

Torq

ue N

m

NOxTorque

able values from 1 to .4), different spark advance angles and different values for the enrichment of the blends uring transients. The main exhaust parameter which had been considered as a constraint at had not to be overcome in case of stoichiometric set up is constituted by NOx

missions. Actually, hydrogen addition implies a higher laminar combustion speed and this auses an increase of combustion temperature and therefore higher NOx emissions . On e contrary, CO and HC emissions are always lower , thanks both to the lower quantity of

arbon and to the improved combustion process. For lean-burn mixtures, not only NOx , but lso HC monitoring had been a decisive parameter that had been taken into consideration. ctually, also HC emissions can raise due to the fact that laminar combustion speed ecreases remarkably. This produces a not complete oxidation of HC. Moreover, higher gas ooling during expansion delays the fuel oxidation, in particularly near cylinder’s walls and in e most hidden parts of the combustion chamber. The first tests using mixtures to feed the

ngine, carried without any modification of the injection control map, had confirmed the reseen NOx emissions increase related to the increasing combustion speed. This fact had quired a modification of the spark ignition time. In Fig. 6.25 it is possible to see that a

spark advance reduction of only 3 degrees (which means a little retard compared to the e methane) brings to a large decrease of NOx emissions, without torque

duction.

Fig. 6.25

1dthecthcaAdcthefore

case of purre


BONG

41-HY – FINAL REPORT – MARCH 2007

0

200

400

600

800

1000

NO

x pp

m

20

30

40

50

Vehi

cle

Spee

d K

m/h

1200 60

0 10 20 30 40 50 60 70 80 90Time s.

-10

0

10

NOx AfterNOx beforeSpeed AfterSpeed Before

0

500

1000

1500

0.95 1.05 1.15 1.25 1.35 1.45Lambda

NO

x pp

m

0

100

200

300

400

500

700

Torq

ue N

m

2000600

NoxTorque

otwithstanding the above reported spark ignition time correction, engine performances with ethane-hydrogen blends had remained not acceptable during ECE driving cycle in terms f emissions, due to the too high NOx emission values, compared to methane. A more etailed examination of the engine behaviour during transients shows that fuel enrichment s mapped in ECU) had been too low, therefore actual λ reaches values comprised

etween 1.1-1.2. As a result, NOx emissions had increased too much. For this reason, a ap correction had been adopted for acceleration phases. This had been allowed by a

dedicated function of electronic injection unit. In this way it had been possible to decrease NOX emissions to desired values, lower than figures obtained with methane (see Fig. 6.26).

Fig. 6.26

For a lean burn blend, research of better AFR (we wanted to reach a value of 100 ppm, the same of pure methane) was limited from λ= 1 to λ= 1,45. Furthermore, the increase of AFR values causes very important power losses, as shown in Fig. 10. Therefore, λ=1,45 had been the maximum value initially fixed (this value substantially reduces NOx) and a series of tests had been produced changing the spark ignition advance to optimize the control strategy in order to increase the performances. Unfortunately, NOx had grown in an exponential way, while power gain hadn’t been significative. It had also been decided that it is more convenient to adopt a lower AFR value without changing the spark advance instead of setting a high λ ith optimal advance timing.

Fig.6.27

Nmod(abm

together w


Emission reduction (% TTW) vs. pure methane

-14,3%

-99,0%

47,6%

-66,7%

-89,5%

170,0%

-42,9%

157,1%

-76,4%

-24,5%

-64,2%

-6,6%

-4,3%

-10,2%

-10,6%

-14,9%

0,7%

-5,2%

-5,6%

-9,9%

-150,0% -100,0% -50,0% 0,0% 50,0% 100,0% 150,0% 200,0%

% CO % HC % N0x % CO2 % net CO2

6.3.6 Results In the following pictures the obtained results of the lab tests for both the fuel consumption and the pollutants and CO2 emissions (for d g conditions) are represented .

Fig. 6.28 : Emission reduction of pollutants and CO2 for a TTW analysis

ifferent operatin

Increase of engine efficiency (%)

0,9%

12,8%

5,2%

11,5%

3,0%

6,0%

9,0%

12,0%

15,0%

0,0%ich. HCNG10 lean HCNG15 stoich. HCNG15 leanHCNG10 sto

Fig. 6.29 : Increase of engine efficiency due to the use of blends vs. CH4

Specific distance (km/kWh)

0,602

0,562

0,595

0,560

0,580

0,600

0,620

0,534 0,539

0,480

0,500

0,520

0,540

METANO HCNG10stoich.

HCNG10 lean HCNG15stoich.

HCNG15 lean

Fig. 6.30 : Distance covered with respect to the energy consumption


42


6.3.7 CONCLUSIONS The analysis of the results of the lab tests can be considered encouraging for the

ndition can be

( for the fuel consumption reduction) and with the use of stoichiometric blends

had been made, as for example the compression ratio

herefore, for both the combustion strategies adopted, the vehicle had succeeded in doing the urban cycle, the engine had worked regularly and the obtained results had been

ncouraging in terms of both consumptions reduction and pollutants and CO2 emission duction as had been demonstrated by the foreign labs and road tests too.

he pollutants emission reduction had been very promising mainly working in stoichiometric onditions. inally, even considering the Swedish works ( that don’t present problems of power losses ith the use of blends) we can say that, starting from the existent motorisations, the trategies that have to be adopted for the modifications must be coherent with the base onstructor philosophy; in our case, we had taken into consideration the IVECO philosophy. onsequently, we consider the obtained results with stoichiometric conditions as the base sults of a possible development of the project that foresees the field experimentation of

ehicles with an IVECO motorisation (for example, industrial vehicles for the transports of oods or waste collecting vehicles). this framework, the reduction of the energetic consumptions increases with blends with a

5% hydrogen content by volume, in a way more than proportional with the increase of een the

continuation of the activities, even if the tests had just covered a short period of time (a few months). It’s well known that the reduction of fuel consumption brings to the enhancement of the pollutants and greenhouses gases emissions; therefore, the optimum cofound dealing with the problem with different approaches, i.e. with the use of lean blends in the first casein the second case ( emissions reduction). Actually, these two approaches correspond to the different conceptual ideas adopted by VOLVO (whose engines are mounted on the urban buses of the “Malmo Hythane project”) and by IVECO (the manufacturer of the DAILY vehicle used for our experimentations) for the realisation of their natural gas motorisation. In our case, dealing with an IVECO engine, that had been designed in order to work in stoichiometric conditions, the adoption of a “lean combustion” strategy had brought us to unsatisfactory results: actually, since no changements in the engine hardwareenhancement and/or the engine overfuelling, with respect to the vehicle’s behaviour, a reduction of the engine specific power had been verified, beyond to the reduction of the power due to the inferior energy content by volume ( - 11% for the blend with a 15% hydrogen content by volume). T

ereTcFwscCrevgIn1hydrogen content, while for the pollutants emissions a significative difference betw

a 10% or 15% hydrogen content by volume hadn’t been verified. use of blends with


43


WP4 – Study G blends in SOFC and related tests This workpackage had fo SOFCs (Solid Oxide Fuel Cells) fuelled by blends of hydrogen and na re hydrogen. The tested SOFCs had been electr an Yttria-doped Zirconia (YSZ) electrolyte, a Lanthanum-Stro and a kel – YSZ – Cermet with a 5% CeO2 anode. For anode contacting a nickel mesh had been used while for

of the use of H2/N

reseen the tests of micro-tubolar tural gas compared to the use of pu

olyte stabilised cells withntium Manganite cathode (LSM) Nic

cathode contacting silver wires and inks had been used. The gas composition had been studied using an online gas cromatograph. The influence of the fuel on the anode performance had been investigated too using impedance spectroscopy. During the first semester, from both literature data and first lab tests it came out that the following reactions seem to be of great interest when a SOFC with a Nickel -YSZ -Cermet is fuelled by a blend of hydrogen and methane.

2

24

22COCCOHCCH

+↔+↔

Equation 1 describes the principle oxidation of hydrogen that

222 21 OHHH ↔+

cons

owe

the water which is produced with hydrogen could oxidise away the

equation for the production of electricity. Because of the gas analythe electrical performance that had been carried on in this projectof significance because even in the case of methane the hydrogeninternal reforming. On the other hand, Equation 2 and 3 describe the potential probThis may lead to a blocked anode where no more gas can find a pphase-boundary (TPB) and/or which was found out in this project the anode. Both cases can lead to a loss in power or can even caSolid Oxide Fuel Cell. To allow for these results, further investigatiin order to verify if a smaller concentration of the carbon hydrogenwater/carbon in the gas would improve the stability and the cell perTo get reference values for the maximum power a certain cell cmicrotubolar SOFCs were driven with pure hydrogen before theused. The change from one gas to another had been done wprevent reoxidation of the anode. For example, in the case of a dmethane at 850 °C working temperature it had been found out that the 10% by volume in methane can be possible for a SOFC. Nevertheless, higher concentration had caused a fast degradationspectroscopy analysis under OCV conditions (open circuit voltagtwo semi-arcs in the Nyquist plot. Each of the arcs could belectrodes.Furthermore, when the cell had been fuelled by a blenvolume, a third process can be determined. Because of the lprocess it is thought that this fact had happened because of a blocarbon which caused diffusion problems. In addition to the recordinwith different dry methane-hydrogen blends an investigation had beif after the degradation a regeneration with hydrogen would be pos


(2) (3)

(1)

titutes the most important

r frequency range of this

as thought that carbon. But in any case

sis and the measuring of , Equation 1 seems to be can be produced through

lem of carbon formation. ath to and from the triple-nickel was unhinged from use the deadening of the ons had been carried out and/or a certain ratio of

formance over time. an deliver all the tested

different test fuels were ithout any interruption to ry blend of hydrogen and till concentrations of H2 of

of the power. Impedance e) normally had showed

e related to one of the d of 20% of methane by

cking effect of deposited g of the cell performance en undertaken to find out sible. It w

44


no regeneration could be observed. Experiments with 66,6% moisture in the gas at a working temperature of 850 °C had never resulted in carbon formation on the anode. But unfortunately with a medium methane concentration a stable performance hadn’t been

big power loss with 2/3 water in hydrogen at the beginning could be

ere was no high reforming activity of the tested anode. With low water concentrations CO had been found in higher concentrations than CO2 and the methane consumption/reforming had decreased with cell degradation and the amount of CO2 had overpassed the one of CO. In addition to the first experiments short stack tests had been carried out too. But unfortunately no analysable results could be found because it hadn’t been possible to build up a working serial cell setup in the available time. Every time when such a short stack had been heated up and started different problems occurred because of mechanical stress. In particular, the sealing broke and a high concentration of nitrogen from the incoming air could be found with gas chromatography and sometimes even flames could be observed too. The gas supply of the cells could no longer be guaranteed and the incoming oxygen had a negative effect on the anode which led to the fast cell degradation. As a conclusion of all the experiments which had been done it can be said that it is not possible to use pure methane in cells with a Nickel-YSZ-Cermet anode. The addition of water allows higher methane concentrations and the increase of Temperature from 850 °C to 900 °C had taken to positive effects for the stability when using hythane.

Fig. 6.31 : Experimental setup

possible. The reason had been due to a delamination of the anode from the electrolyte which also reduced the possible reaction zones. A comparable series of experiments had been done at a working temperature of 900 °C. In order to get reference values the cell had been put into operation with hydrogen for about 14 hours. Up to 75% methane in the fuel didn’t cause higher degradation than that found with hydrogen and no carbon deposition had been observed. But a observed in contrast to the experiment at 850 °C. It had been found that with this high concentration of water at a working temperature of 900 °C the anode structure seemed to break up and also some determination of the anode occurred. Gas chromatography analysis during the experiments had showed that th


45


Fig. 6.32 : Typical cell performance after changing from pure H2 to pure CH4

Fig. 6.33 : Performance comparison over time with dry blends


46


Fig. 6.34 : IS analysis with hydrogen after stabilisation

Fig. 6.35 : IS analysis after 20% methane test


47


Tab. 6.11 : Possible reactions in a SOFC

blends nd homologation procedures for single vehicle prototypes

6.5.1 Introduction

of

dedicated Authorities

6.5 WP5 – Analysis of the regulations for the use of H2/NG a

Aim of this WP had been the collection and presentation of the Regulations and Standards that can be applied to obtain the permission of circulation of vehicles fuelled by blends hydrogen and natural gas , with an internal combustion engine or a fuel cell. In particular, this study will be used as a guideline for the inspection of a single prototype of an industrial vehicle with an internal combustion engine fuelled by blends of hydrogen and natural gas, till a 30% hydrogen content by volume. The state of the art on the activities that concern the development of Regulations and Standards is represented by the documents that had been produced by the Working Groups ISO and ECE-ONU. In these working groups Standards and Regulations are under study and in the near future they will become fundamental legal requisites for the homologations all over the world (GTR – Global Technical Regulation). The state of the art on the reduction of the National Regulations under development in Italy will be discussed too. In order to let the circulation on streets of both the first prototypes and little pre-industrialised fleets of vehicles fuelled by blends of hydrogen and natural gas, different Countries are preparing their internal National Regulations. In Europe different Nations have National homologation procedures available (i.e., Germany). A possible “inspection procedure” is under development in Italy. In general, the modification of vehicles’ components is permitted just in cases of inspection of a few vehicles to be tested on the street as pilot fleet an analysis and the “inspection procedure” with which the “Homologative Body” evaluates the possible consequences on the safety of the users, limiting the operational modalities eventually. In case of vehicle’s modifications, they must be subjected to analysis, inspection visit and test on the road by the (in Italy, the Minister of Transports). A description of the base principles of a RISK ANALYSIS (RAMS – Reliability, Availability, Maintenance and Safety) will be reported. In the case of vehicles fuelled by hydrogen,


48


mainly because of the absence of Regulations and Standards valid for the authorities, a safety analysis of the hydrogen storage systems , the conduction of hydrogen to the engine

s of hydrogen and natural gas ith an internal combustion engine (ICE) will be reported too.

and the security systems adopted had been requested. Furthermore, an hypothesis of test plan that could be used, in Italy, for the inspection procedures of a single vehicle fuelled by hydrogen or by blendw


49


6.5.2 Technical considerations on the combustion of CH4/H2 blends in internal combustion engines

The use of blends of hydrogen and methane in the automotive field had started decades ago, with the initial aim of increasing the natural gas flame speed and extend the flammability ranges. A wide literature exists, reporting the results of these experimentations that, even if they agree with the positive effects in terms of emissions reduction and better engine efficiency, they even present some contraddictions, mainly concerning the NOX emissions. In Fig. 2.1 the principal technical features of the most common fuels and hydrogen used in the OTTO CYCLE engines ( with a controlled ignition) , in order to compare them and underline hydrogen wider flammability range and its higher flame speed.

Gasoline GPL

(propane – butane)

Methane Hydrogen

Lower heating value [MJ/Kg] 44,4 46 ÷ 45,4 50 120

Octan number RON 90 ÷ 98 100 120 130

C/H Ratio 0,54 0,38 ¸ 0,4 0,25 0 Thermal tonality[MJ/ m3] 3,65 3,48 3,18 2,97

Combustion speed [cm/sec] 43 ÷ 47 43 ÷ 47 35 ÷ 40 200 ÷ 400

Lower flammability value at environmental P 1,0 % vol. 2,1 ¸1,5 % vol. 5,0 % vol. 4,1 % vol.

Higher flammability value at environmental P 7,6 % vol. 9,5 ÷ 8,5 % vol. 15 % vol. 72,5 % vol.

Vapour density at Env. P [Kg/m3] 4,75 1,83 ÷ 2,42 0,67 0,08989

Vapour density/Air ratio 3,9 1,5 ÷ 2,0 0,56 0,070

Liquid density [Kg/ m3] 740 [15°C]

585 ÷ 573 [15°C]

423 [-161°C]

70 [-252°C]

Autoignition temperature 320 °C 465 °C 540 °C 560 °C

Boiling T (°C) at 1 bar 125 °C - 42 °C ÷ - 1 °C - 161 °C - 252 °C

Vapour tension REID (100 °F)

0,25 ÷ 0,45 bar (abs)

10,0 ÷ 2,5 bar (abs)

Propane - Buthane

-

Tab. 6.12 – Principal technical features of fuels: Gasoline, GPL, Methane and

Hydrogen


50


It’s interesting to observe that methane, as component of natural gas, is characterised by a good flammability range (5 ÷ 15 %vol) in air, with respect to gasoline (1 ÷ 7 %vol) and for hydrogen it is even wider (4 ÷ 72 %vol) with a consequent possibility of using lean blends with a correspondent NOX emissions reduction. Methane is characterised by a lower flame speed with respect to gasoline. In order to burn, methane needs, at the beginning of the combustion, an energy quantity that must be supplied to the reaction from the outside ( endothermic reaction) , making difficult both the ignition of the combustion and the flame propagation. Therefore, a hydrogen percentage in natural gas can lead to a big increase of the flame speed, with a benefit for the combustion and even widens the flammability range allowing even leaner blends with a correspondent pollutants reduction. Considering that the presence of hydrogen reduces the C/H ratio of the fuel, even the CO2 emissions are reduced. In the present study, the use of blends of hydrogen and natural gas in internal combustion engines for mobility applications had been studied. The storage and fuelling system of the hydrogen and natural gas blends will be reported in Fig. 6.36. The system architecture is similar to the methane’s one; the differences with respect to methane, keeping H2 percentages lower than 30%, would be just a few (for example, the optimisation of the engine mapping, the components materials, packings and working pressures).

Cylinder

ECU

Cylinder

Cylinder

Cylinder

Safety multivalveon the cylinders Electrovalve

Pressure regulator

GAS INJECTORS

ASPIRATION COLLECTOR

EXAUST COLLECTOR

CATALYSERENGINE SENSORS

Control system

ENGINE

CANDLES

H2 SENSOR

Watertight room

Fig. 6.36 – Storage and fuelling system for H2/CNG blends in an ICE


51


Particular attention have to be adopetd for the safety systems, in order that, in case of any bad functioning in the system, it would keep the fuel in the cylinder and that, in case of fuel losses, would signal its presence with specific hydrogen sensors. Even the different system weather strips must be studied because of the presence of the hydrogen molecole, smaller than methane’s, and so more movable to the outside. Even if most of the studies on the use of hydrogen for mobility applications are developing towards the FUEL CELLS solution, that foresee higher nominal efficiencies ( till the 70% and beyond), considering the complete traction system ( auxiliar services for the FC and electrical transmission system) , the overall system efficiency reaches levels similar to the ones for an ICE, even if quite higher. For this purpose, Fig. 6.37 compares the efficiency of an overall system with an ICE and with a FC.

ICE

RICARDO

Fig. 6.37 – Overall efficiency for a system with an ICE or a FC

These data allow the use of hydrogen as fuel for an internal combustion engine for a period even longer than a transition period, before fuel cells will be on the market at accessible costs. This transition period would allow, along with a sensible increase in emissions reduction and engine efficiency, even a progressive development of the necessary infrastructures for hydrogen distribution, as well as the development of technologies of hydrogen production.


52


6.5.3 Technical features of hydrogen and H2/NG blends for their use in an internal combustion engine (ICE)

We underline the principal technical pro and cons linked to the use of blends of hydrogen and natural gas in an internal combustion engine:

The wider ignition range (in air) would allow a stable combustion for lean blends (λ

lean burn) but would determine autoignition problems and backfires;

It’s possible that ,in presence of high hydrogen percentages, a modification of the ignition system would be necessary, in order to take into consideration the candles necessities ( thermal degree) and avoid ignitions for hot spots;

The high octane number (> 130) of the blends gives the possibility of using a high compression ratio with an increase of the efficiency of the thermodinamical cycle;

The low density of methane and even lower density of hydrogen denotes a low specific chemical energy of the blend with consequent reduction of the engine power with respect to the analogous methane or gasoline engine;

The hydrogen molecule dimensions determine fuel losses in the outside air or in the carter engine with possible little breaches;

The high flame speed implies high temperatures in the combustion process with high NOx emissions and even high losses of thermal energy for undesirable dispersions through the combustion chamber walls.

Another critical aspect linked to the use of blends of hydrogen and natural gas in internal combustion engines is characterised by an inferior vehicle’s fuel autonomy because of the reduction of the energy that can be stored in the compressed gas cylinders. Actually, even considering a vehicle with the same efficiency of a methane vehicle, the low energetic density of compressed hydrogen determines This effect assumes importantance in dependence of the hydrogen percentage contained in the blend. In Fig. 6.38 the energetic content of CNG/H2 blend in cylinders versus the hydrogen percentage had been reported.


53


40

50

60

70

80

90

100

0 5 10 15 20 25 30Hydrogen content [%]

Stor

ed e

nerg

y [%

]

Fig. 6.38 – Energetic content of a CH4/H2 blend stored at a P of 20 MPa and T = 288 °K (15 °C), versus the hydrogen content (by volume) in the blend

6.5.4 Performances and pollutants emissions of an ICE fuelled by blends of hydrogen and methane – Literature data

Before starting a development programme for a pilot fleet of vehicles fuelled by blends of hydrogen and natural gas it is necessary to collect a consistent number of information about similar experiments. Actually, the blends of hydrogen and methane, even known with the registered mark “HYTHANE” – www. hythane.com, are under study in different parts of the world. From a first analysis of the wide literature available concerning the use of blends of methane and hydrogen in internal combustion engines, it’s possible to make the following considerations, on the basis of tests that had been carried on in different parts of the world.

The optimal hydrogen percentage for the emissions reduction and engine’s

performance is about 20-30% hydrogen content in CNG

The storage pressure is equal to the one of CNG ( 200 bar)

From roller bench tests the following results had come out:

o Energetic consumption equal to the CNG’s; o NOx reduction of about 50%; o NMHC reduction of about 50-60% ( non methanic hydrocarbons); o CO reduction of about 10%; o CO2 reduction of about 25%.

From the tests on vehicles on the road, the following average results had come out:

o Energetic consumption: + 12%; o NOx reduction of 55%; o Other pollutants reduction similar to the one of the roller test bench.


54


It’s possible to note a correspondence between the results taken over in the lab and on the road concerning the pollutants emissions; it’s not possible to say the same for the energetic consumption. A first reason could be represented by the lack of an adequate optimisation of the carburation and transients programming that during the functionality on the road assumes relevant significance.This assumption can let us conclude that in a future development of the experimental programme, great care will be dedicated to this aspect. In general, all the literature that had been analysed agree with a substantial reduction of NOx emissions, obtainable thanks to a dedicated engine characterisation. The use of blends of hydrogen and natural gas in internal combustion engines for pure methane, without any modification, implies an increase of NOx emissions, substantially derived by a higher flame temperature. In order to avoid this phenomenon and to aim at a better engine efficiency, all the studies in this field are oriented to a lean combustion with an optimal λ coefficient equal to:

( )( ) 6.1≅=

stFA

FA

λ

where: A = air mass F = fuel mass (natural gas/hydrogen blend) The reduction of NOx emissions can be obtained reducing the combustion temperature, realising the exaust gases recirculation ( EGR) that shifts the equilibrium of the oxidation reaction of nitrogen towards a decrease of NOx formation. Fur further details, we demand to other spedific studies on this topic, among which we underline the following : SAE 2000-01-2824 "Hydrocarbon Emissions from a SI Engine Using Different

Hydrogen Containing Gaseous Fuels”

SAE 2002-01-0243 “Ford Hydrogen Powered P2000 Vehicle”

SAE 2002-01-2686 "Hydrogen Addition for Improvemed Lean-Burn Capability of Slow-and Fast-Burning Natural gas Combustion Chambers"

SAE 2004-01-2956 "Hydrogen-Blended Natural Gas Operation of a Heavy-Duty Turbocharged Lean-Burn Spark Ignition Engine"

SAE 2004-01-1929 "Knock Characteristics and Performance in an SI Engine With Hydrogen and Natural Gas Blended Fuels"

SAE 2005-01-0235 "Emission Results from the New Development of a dedicated Hydrogen-Enriched Natural gas Heavy-Duty Engine"

SAE 2005-01-3770 "A Fuel Quality Sensors for Fuel Cell Vehicles, Natural Gas Vehicles, and Variable Gaseous Fuel Vehicles"

SAE 2005-24-009 "Ignition and Combustion Characterization of Hydrogen/Methane Mixture by Visualization in a Rapid Compression Machine (RCM)"


55


SAE 2006-01-0653 "Direct Injected Hydrogen Methane Mixture in a HD Compression Ignition Engine"

SAE 2006-01-0651 "Aspect Regarding the Combustion of Hydrogen in Spark Ignition Engine"

SAE 2006-01-0433 "Hydrogen ICE Vehicles Testing Activities"

6.5.5 ISO STANDARDS – Normative activity on hydrogen and CNG/H2 blends ISO (International Organization for Standardisation) is the Normative International Organisation that see the participation of bodies that deal with Normative of different Countries that, on a voluntary basis, activate themselves for the redaction of Standards in the different industrial fields. The “voluntary” nature of the organisation is particularly important and for this reason ISO STANDARDS that hasn’t got law value can acquire it indirectly, if they are cited in the approved normatives or in the international tenders for suppliers. In the automotive sector ISO had constituted the Technical Committee ISO/TC197 that deals with the hydrogen applications in general ( production, distribution, use, …) ISO had even constituted the Technical Committee ISO/TC58 that deals with the normative aspects of pressurised storage systems both for methane and hydrogen. In the ISO/TC22 framework two Subcommittees had been constituted and they deal with the Normatives for gaseous fuels:

ISO/TC22/SC25 " Vehicles that use the gaseous fuels methane, hydrogen and GPL” ISO/TC22/SC21 " Electrical and fuel cell vehicles”

In the following the activities of the main ISO Technical Committees that deal with methane and hydrogen are summarised.

6.5.6 ISO/TC197 “Hydrogen technologies”

Chairman: Mr. Randy Dey (Canada) Secretary: Ms. Sylvie Gingras – SCC (Canada) Objectives: Standardisation activity in the field of systems and components for the

production, storage, transport, measure and use of hydrogen.

At the moment, in the TC197 framework, the following Working Groups are active:

- WG 1 Liquid hydrogen - Land vehicles fuel tanks - WG 5 Gaseous hydrogen - Land vehicle filling connectors - WG 6 Gaseous hydrogen and hydrogen blends - Land vehicle fuel tanks - WG 8 Hydrogen generators using water electrolysis process - WG 9 Hydrogen generators using fuel processing technologies - WG 10 Transportable gas storage devices - Hydrogen absorbed in reversible metal

hydride - WG 11 Gaseous hydrogen - Service stations - WG 12 Hydrogen fuel - Product specification


56


Published Standards:

Standard number Title Status update

ISO 13984 Liquid hydrogen – Land vehicle fuelling system interface.

(Currently under systematic review)

ISO 14687 Hydrogen fuel – Product specification.

(To be subjected to a systematic review upon

completion of ISO/TC 197 WG 12 work)

ISO/PAS 15594 Airport hydrogen fuelling facility. (Published in 2004) ISO/TR 15916 Basic considerations for the safety of

hydrogen systems. (Published in 2004)

ISO 17268 Compressed hydrogen surface vehicle refuelling connection devices

Under revision (some technical errors have been

identified).

Tab. 6.13 Standards that are going to be edited:

Standard number Title Status update ISO/FDIS 13985 Liquid hydrogen – Land vehicle fuel

tanks. Final publication expected for

June 2006. Actually still no published.

ISO/DIS 15869.2 Gaseous hydrogen and hydrogen blends - Land vehicle fuel tanks

Final publication expected for April 2007.

ISO/DIS 22734-1 Hydrogen generators using water electrolysis process–Part 1: Industrial and commercial

applications.

Final publication expected for January 2007.

ISO/CD 22734-2 Hydrogen generators using water electrolysis process– Part 2:

Residential applications


ISO/DIS 16110-1 Hydrogen generators using fuel processing technologies-Part 1:

Safety

Final publication expected for March 2007.

ISO/CD 16110-2 Hydrogen generators using fuel processing technologies-Part 2: Test

methods for performance

Final publication expected for March 2008.

ISO/CD 16111 Transportable gas storage devices - Hydrogen absorbed in reversible

metal hydrides

Technical Specification expected for June 2006. International Standard

expected for September 2007ISO/AWI TS

20012 Gaseous hydrogen – Fuelling

stations Technical Specification

expected for February 2007. ISO/AWI 14687-2 Hydrogen fuel – Product

specification – Part 2: PEM fuel cell applications for road vehicles

Technical Specification expected for June 2006. International Standard

expected for January 2010 ISO/AWI 26142 Gaseous hydrogen – Hydrogen

detectors International Standard

expected for September 2009

Tab. 6.14


57


Since the activities for the editing of Normatives and Standards in the hydrogen field is generally fragmentary as well as its use as a fuel for mobility, in the framework of the TC197 works, a new Working Group had been recently created, having as objective the systemic collection of Normatives and Standards concerning the hydrogen components for different applications. From the collection and catalogation of these documents in different topics, a map can be produced with the redundancies and eventual normative lacks. In order to end the works, the Working Group will take over the necessary actions in order to cover the noticed lacks beginning to work for the editing of new Standards or for the revision activity of existent “Standards”. The Working Group that had been created is called AD HOC GROUP ON HYDROGEN COMPONENTS” and the first meeting had been held in January 2007, with the participation of the following members:

ISO/TC22/SC25 “Vehicles using gaseous fuels (CNG, LPG, H2)” ISO/TC22/SC21 “Electrically propelled road vehicles and fuel cell" ISO/TC58 “Gas cylinders”

6.5.7 ISO/TC22/SC25 “Vehicles using gaseous fuels (CNG, LPG, H2)”

Chairman: Mr. Aldo Bassi (Italy) Secretary: Mr. Gilberto Maurizio – CUNA (Italy)

Objectives: Standardisation activity in the field of systems and components for the

use of gaseous fuels in the vehicles propulsion systems. The Subcommittee has the competency on the use of GPL ( Liquified Petroleum Gas) , Natural Gas and Hydrogen

At the moment, in the TC22/SC25 framework, the following Working Groups are active:

- WG 1 Compressed natural gas refuelling connector - WG 2 Design principles and installation of vehicle fuel systems - WG 3 NGV fuel system components

The activities taken over by the TC22/SC25 till now had concerned the editing of Standards for natural gas vehicles. For this reason the SC25 had produced a full set of Standards for these applications. The analogies that exist between the storage and refuelling systems on vehicles for natural gas and hydrogen allow to consider the solid experience of the ISO/TC22/SC25 experts in the field of the components for high pressure fuels.


58


Published Standards:

Standard number Title Status update ISO 14469-1:2004 Road vehicles -- Compressed

natural gas (CNG) refuelling connector -- Part 1: 20 MPa

(200 bar) connector

Published in 2004

ISO 15500 series (1÷19)

Road vehicles -- Compressed natural gas (CNG) fuel system

components

Published in 2000÷2001 (Actually under systematic

review) ISO 15501-1:2001 Road vehicles -- Compressed

natural gas (CNG) fuel systems -- Part 1: Safety requirements

Published in 2001 (Actually under systematic review)

ISO 15501-2:2001 Road vehicles -- Compressed natural gas (CNG) fuel systems

-- Part 2: Test methods

Published in 2001 (Actually under systematic review)

Tab. 6.15

Standards under development:

Standard number Title Status update ISO/DIS 14469-2 Road vehicles -- Compressed

natural gas (CNG) refuelling connector -- Part 2: 20 MPa (200 bar) connector Size 2


ISO/PRF 14469-3 Road vehicles -- Compressed natural gas (CNG) refuelling connector -- Part 3: 25 MPa

(250 bar) connector

Proof of an International Standard. Technical work is done. Final publication is in

progress. ISO/WD xxxx.1 Road vehicles – Compressed

Gaseous Hydrogen (CGH2) and Hydrogen Blends fuel system components – Part 1: General requirements and definitions

Decision is going to be taken to develop a new standard or

not.

ISO/WD xxxx.2 Road vehicles – Compressed Gaseous Hydrogen (CGH2) and

Hydrogen Blends fuel system components – Part 2:

Performance and general test methods


not.

ISO/WD xxxx.3 Road vehicles – Compressed Gaseous Hydrogen (CGH2) and

Hydrogen Blends fuel system components – Part 3: Pressure

regulator


not.

ISO/PWI xxxxx Road Vehicles – Compressed Gaseous Hydrogen (CGH2) and Hydrogen Blends fuel systems

components

Proposal in agenda for SC25 meeting scheduled for next

04/05 October 2006 in Suresnes (F).

Tab. 6.16


59


6.5.8 ISO/TC22/SC21 “Electrically propelled road vehicles”

Chairman: Mr. Dietrich Sahm (Germany) Secretary: Mr. Egbert Fritzsche – DIN (Germany)

Objectives: Standardisation activity in the filed of systems and components for

electrical vehicles. The Subcommittee is competent even for both fuel cells and electrical components of fuel cell vehicles.

At the moment, in the TC22/SC21 framework, the following Working Groups are active:

- WG 1 Vehicle operation conditions, vehicle safety and energy storage installation - WG 2 Definitions and methods of measurement of vehicle performance and of

energy consumption

Published Standards (that deal with fuel cell vehicles fuelled by hydrogen):

Standard number Title Status update ISO 6469-1:2001 Electric road vehicles -- Safety

specifications -- Part 1: On-board electrical energy storage

Published in 2001

ISO 6469-2:2001 Electric road vehicles -- Safety specifications -- Part 2: Functional

safety means and protection against failures

Published in 2001

ISO 6469-3:2001 Electric road vehicles -- Safety specifications -- Part 3: Protection of

persons against electric hazards

Published in 2001

ISO 8713:2005 Electric road vehicles – Vocabulary Published in 2005 ISO 8714:2002 Electric road vehicles -- Reference

energy consumption and range -- Test procedures for passenger cars and

light commercial vehicles

Published in 2002

ISO 8715:2001 Electric road vehicles -- Road operating characteristics

Published in 2001

ISO 23273-1:2006 Fuel cell road vehicles -- Safety specifications -- Part 1: Vehicle

functional safety

Published in 2006

ISO 23273-2:2006 Fuel cell road vehicles -- Safety specifications -- Part 2: Protection

against hydrogen hazards for vehicles fuelled with compressed hydrogen

Published in 2006

ISO 23273-1:2006 Fuel cell road vehicles – Safety specifications – Part 1: Vehicle

functional safety

Published in 2006

ISO 23273-2:2006 Fuel cell road vehicles – Safety specifications – Part 2: Protection

against hydrogen hazards for vehicles fuelled with compressed hydrogen

Published in 2006

Tab. 6.17


60


Standards under development (that deal with fuel cell vehicles fuelled by hydrogen):

Standard number Title Status update ISO/DIS 23273-3 Fuel cell road vehicles -- Safety

specifications -- Part 3: Protection of persons against

electric shock

ISO/CD 23828-1 Fuel Cell Hybrid Electric Road Vehicles -- Energy consumption measurement -- Part 1: Using

compressed hydrogen

ISO/WD 23829-1 Pure Fuel Road Vehicles -- Energy consumption

measurement -- Part 1: Using compressed hydrogen

Tab. 6.18

6.5.9 TC58 “Gas cylinders”

Chair: Dr. Chris Jubb (United Kingdom) until the end of 2007 Secretary: Mr. Stephen Elliott – BSI (United Kingdom)

Objectives: Standardisation activities in the field of gas cylinders, the components

for their junctions, their use, construction and manteinance.

At the moment, in the TC58 framework, concerning the hydrogen vehicles, the following Working Group is active:

- WG 7 Compatibility between gases and materials

Published Standards (concerning hydrogen vehicles):

Standard number Title Status update ISO 11114-4:2005 Transportable gas cylinders --

Compatibility of cylinder and valve materials with gas

contents -- Part 4: Test methods for selecting metallic materials

resistant to hydrogen embrittlement

Published in 2005

ISO 11439:2000 Gas cylinders -- High pressure cylinders for the on-board

storage of natural gas as a fuel for automotive vehicles

Published in 2000

Tab. 6.19


61


Standards under development (concerning hydrogen vehicles):

Standard number Title Status update ISO/FDIS 19078 Gas cylinders -- Inspection of the

cylinder installation, and requalification of high pressure

cylinders for the on-board storage of natural gas as a fuel

for automotive vehicles

Tab. 6.20

6.5.10 ECE-ONU / UN-GTR Regulations

UN-ECE (United Nations – Economic Commission for Europe) is an international organisation, that had been constituted in the United Nations Framework, with the aim of promoting the economical development among the 56 Member States. For this purpose, UN-ECE organises some Working Groups or “WORLD FORUM” among the Member States, as a mediator towards the international legislation concerning commerce, transports and environment. It even develops statistical analysis on economical and environmental topics. In the framework of UN-ECE, the Working Group that deals with Terrestrial Transports is the WP29 “World Forum for Harmonisation of Vehicle Regulation”. In the WP29 framework the Working Group “Informal Group on Hydrogen Fuel Cell Vehicles”had been created for the editing of a Regulation under the form of "Global Technical Regulation" (GTR-HFCV) presided by Germany (Mr. Albus).The GTR-HFCV Working Group is organised in two working subgroups (SWG):

o Environment emissions H2 consumption o Safety H2 storage, vehicle crash electric safety

This organisation, whose structure is illustrated in Fig. 6.39, aims at editing the GTR Regulation, that will be a Regulation valid for all Members, including United States, Japan, European Union, permitting one homologation for the commercialisation of the vehicles all over the world. The fulfilment of the editing and approval by the GTR concerning the hydrogen vehicles is attended before the end of the decade (2008 ÷ 2010). Most probably, the dispositions concerning the use of blends of methane and hydrogen will be included too.


62


1.1. WP29/AC3

PROJECT MANAGER

GTR-HFCV Mr. Albus

SWG Safety H2 storage, vehicle

crash electric safety

SWG Environment emissions

H2 consumption

1.2. GRPE

SGE (Perujo del JRC-ISPRA) SGS (to be defined)

LPG, CNG, H2 Road Vehicles

ISO TC22 SC25

Decision for cooperation between TC197 and TC22 was

already taken on 19.02.02

ISO H2 Voice

1.2.1. GRSP

Hydrogen Technologies ISO TC197

EIHP is a partnership between the European Hydrogen Industry and the European Commission. This consortium had been created to provide inputs for regulatory activities on a European and global level to facilitate harmonized Procedures for the approval of hydrogen fuelled road vehicles Electric, Hybrid, FC Vehicles

ISO TC22 SC21

EIHP2 Partnership

H2 Industry mobile voice and stationary

Fig. 6.39 – International Organisation for the editing of Homologation Regulations of vehicles fuelled by hydrogen ( and CH4/H2 blends)

The UN-ECE organisation, along with ISO, are the principal organisms of Regulation and international standardisation in the field of vehicles fuelled by gaseous fuels. The substantial difference between the two organisations, that is underlined by the different objectives, is associated to the fact that UN-ECE produces Regulations that become laws, through the reception agreements that the Member Countries had signed adhering to the organisation. On the contrary, ISO is a voluntary organisation and the technical indications contained in the documents that it produces are just “good engineering” indications. Nevertheless, with the lack of applicable legislative Regulations, many Countries use the ISO Standards as reference. For this reason, when the development of a national or international Regulation starts, ISO Standards are always considered. Furthermore, thanks to a recent agreement ISO-UN-ECE, the ISO Standards can be included in the ECE Regulations, when approved, simply reporting the publication number and the date. In order to compare the two organisations, in Fig. 4.2 the Working Groups Schemes that are now active in the hydrogen and methane fields applied to transports are reported.


63


ECE-Rxx : Liquid H2 System & Components

ECE-Ryy : Compressed H2 System & Components

ECE-Rzz: Fuel Cells

ISO International Organization

Standardization

TC58 Gas cylinders

WG1 Liquid fuel

tanks

WG5 Gas Filling connector

s

WG11 Service Stations

WG12 Product

Specifications

TC197 Hydrogen

technologies

WG6 Gaseous fuel tanks

WG8 Electrolysi

s processes

WG9 Fuel

processing tech.

TC22 Road

Vehicles

TC22/SC21 Electric road

vehicles, Fuel Cells.

WG1 Refuelling connector

WG2 Design

principles and

installation of vehicle fuel

WG3 Fuel system components.

WG11 LPG Road Vehicles

Containers

UN / ECE United Nations

Economic Commission for

Europe

WP.29

Inland Transport Committee

Working Party on Pollution and

Energy

Ad Hoc Group H2 and Fuel Cell GRPE

GRPE

TC22/SC25 Road vehicles using

LPG, CNG, H2

WG10 Metal

Hydrides

Global Technical

Regulations (GTR)

Fig. 6.40 - International organizations for the development of regulations for hydrogen

vehicles

Since the definitive emission of GTR for the hydrogen vehicles is foreseen not before 2008, some Countries, like Germany, use two documents written by GRPE between the end of 2003 and the beginning of 2004 (but not approved yet) for the homologation of single vehicles for fleet applications. Furthermore, a series of bozze di emendamenti for the modification of ECE-ONU Regulations concerning the homologation of vehicles (for example the measurement of the engine power, consumptions, pollutants emissions,…) that could permit their application even to hydrogen vehicles. In April 2005 Japan, waiting for the GTR Regulations, had emitted a Regulation for the approval of hydrogen vehicles on the national territory.


64


6.5.11 European Commission projects for the homologation of H2 vehicles The actual state of the art of the technological development of hydrogen vehicles, with internal combustion engine or fuel cells, is generally considered mature for proceeding with the first tests on the road for fleet applications. Nevertheless, since there aren’t approved homologation Regulations yet, the different European and Extraeuropean Countries had developed/are developing temporary Regulations, with the aim of developing a successive single GTR Regulation, as had been explained previously. For example, the United States and Japan had already edited some experimental Regulations in order to permit the circulation on street of fleets of hydrogen vehicles. On the contrary, in the European Community an applicable Regulation, even temporary, doesn’t exist yet. Some Member Countries had singularly provided to give the permission of the circulation of some test vehicles (for example Germany). The Working Group “Hydrogen and Fuel Cell Vehicles” in the UN-ECE framework, that had been introduced previously, had developed a complete draft of a Regulation for the homologation of hydrogen vehicles. Waiting for its emission in the form of a GTR Regulation, the European Commission had activated itself for the emission of a draft of a UN-ECE Regulation in the form of European Regulation (or European Directive). The working Group that deals with this initiative is directed by Mr. Laguna Gomez (UE Dependent) and the draft of this UN-ECE Regulation is now under study thanks to a public enquiry in order to arrive to its definitive emission in the first months of 2007. The homologation ( Type – Approval) is a procedure with which a Member State certificates that a certain type of vehicle satisfies the technical and administrative prescriptions concerning the following topics:

Active and Passive Security Environmental Protection Performances

The aim of a homologation procedure is the permission for a vehicle to be put on the market. The concept is applicable both to the components and to the system. The European Union, dealing with the problem of homologation of hydrogen vehicles, had started the EIHP Project (European Integrated Hydrogen Project), financed by the European Commission and had developed two drafts (liquid and gaseous hydrogen) on the security aspects of the hydrogen components to be installed on the vehicles. The two drafts have a structure similar to the one of the Regulations for CNG vehicles (ECE-ONU R.110). The two proposals, originally developed to become new ECE-ONU Regulations, are actually under discussion to become EU Directives or Regulations. The proposals, under definition at EU level, will report the technical measurements to be applied for the homologation of all the components of the storage and fuelling systems for liquid or gaseous hydrogen ( cylinders/tanks and components). They will also include the measurements for the installation of these components or systems on the vehicles. For example, the measurements concerning the following principal components will be reported:

Pressure relief device Pressure regulator Valves Heat exchangers Refuelling connectors Sensors Flexible fuel lines


65


The principal topics included in the two Regulation drafts are the following:

- The hydrogen components, tanks and cylinders included, must work correctly

and safely. They have to be constructed in order to work under safety conditions when subjected to the operative electric, chemical, thermal and mechanical conditions foreseen without presenting losses;

- The materials used for the realisation of the hydrogen system must be

compatible with liquid and gaseous hydrogen. They must resist to the foreseen temperature and pressure conditions. The hydrogen system must be installed taking care of its protection from external damns ( for example crashes, street stones, and must be prevented by eventual vehicle heat sources);

- The hydrogen tank must be installed on the vehicle permanently and can be

removed exclusively for maintainance reasons. It must be adequately protected by every type of corrosion. The tank must be installed and fixed so that the accelerations that could undergo during its operative period, considering the tank full, could be absorbed without damns to the components that are important with regard to the security aspects. In case of hydrogen losses or intentional loss, a possible hydrogen accumulation in vehicles concavities must be strictly avoided;

- The test procedures foreseen by the Type 1, 2, 3 and 4 cylinders for compressed

hydrogen, are reported in Tab. 6.21:

CYLINDER TYPE TEST 1 2 3 4

Burst Test ٧ ٧ ٧ ٧ Ambient Temperature Cycling Test ٧ ٧ ٧ ٧ LBB Performance Test ٧ ٧ ٧ ٧ Bonfire ٧ ٧ ٧ ٧ Penetration Test ٧ ٧ ٧ ٧ Chemical Exposure Test ٧ ٧ ٧ Composite Flow Tolerance Test ٧ ٧ ٧ Accelerated Stress Rupture Test ٧ ٧ ٧ Extreme Temperature Cycling Test ٧ ٧ ٧ Impact Damage Test ٧ ٧ Leak Test ٧ Permeation Test ٧ Boss Torque Test ٧ Hydrogen Gas Cycling Test ٧

Tab. 6.21 – Test procedures foreseen for compressed hydrogen (CGH2) in

the draft of EU Regulation


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The definitions of the different cylinders typologies are the following:

TYPE-1 100% Metal Cylinder ( Steel – Aluminium) TYPE -2 Metallic liner reinforced with a continuos resin filament (as a coil on the cylindric part) TYPE-3 Metallic liner reinforced with a continuos resin filament (entirely in composite material)

For the homologation of components for the hydrogen system, the drafts under analysis need the tests indicated in Tab. 6.22. Tests

Components Tests on materials

Resistance to

corrosion Life Time

Hydraulic pressure

cycles

Internal resistance

External resistance

Electrovalves ٧ ٧ ٧ ٧ ٧ ٧ Junctions ٧ ٧ ٧ ٧ ٧ Flexible tubes ٧ ٧ ٧ ٧ ٧ Heat exchangers ٧ ٧ ٧ ٧ Hydrogen filters ٧ ٧ ٧ ٧ Manual valves ٧ ٧ ٧ ٧ ٧ ٧ Back pressure valves ٧ ٧ ٧ ٧ ٧ ٧

Pressure Regulators ٧ ٧ ٧ ٧ ٧ ٧

Safety valves fuses ٧ ٧ ٧ ٧ ٧ ٧

Overpressure valves ٧ ٧ ٧ ٧ ٧ ٧

Fuelling connectors ٧ ٧ ٧ ٧ ٧ ٧

Hydrogen sensors ٧ ٧ ٧ ٧ ٧

Tab. 6.22 – Test procedures requested for the homologation of the components of the

gaseous hydrogen system (CGH2) in the draft of EU Regulation

The principal activities developed or that will be developed for the emission of the EU Directive/Regulation, are the following:

First meeting of the Working Group that had been held on the 2nd of March 2006, with representatives of the European Commission, Industry and Member States

Necessity of a study on the impact that the Regulations will have on the markets Consultation via Internet foreseen before Summer 2006 ( under development) The adoption by the European Commission foreseen before the end of 2006 or

the beginning of 2007


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Ulterior proposals for the emandment of the existent European Directives, necessary for the definition of the tests for both pollutant emissions and consumption measurements, to be applied even to hydrogen.

6.5.12 Development of national regulations in Italy for the inspection of Hydrogen or CH4/H2 vehicle

Since there aren’t EU Directives or Regulations, many European Countries had developed, or are developing, National Regulations, for temporary or experimental purposes. The aim of such National Regulations is the permission of circulation on street of fleets of experimental pre-industrialised fleets.In Italy some Working Groups are active in order to write down some homologation Regulations or to follow the International Regolamentary and Standardising activities. In the following paragraphs the most important activities of the Working Groups active in Italy are described. 6.5.13 Mirror Committee H2 Italia

In the framework of the Italian Association for Hydrogen H2IT, at the beginning of 2004 an informal group called “ Mirror Committee H2 Italia” had born, with the aim of fostering the information exchange among the different Italian Technical Committees that participate in the international organisations for the compilation of Regulations and Standards ( ISO, CEN, GRPE, PLATFORM H2…). The Italian Technical Committees that participate in the Mirror Committee H2 are the following: CUNA - Commissione tecnica di Unificazione Nazionale dell’Autoveicolo (Technical Commission of National Unification of the Autovehicle) CUNA is a non profit association, associated to UNI, officially registered in Italy with the aim of contributing to the solution of technical unification topics in the field of autovehicles, their components or connected products. Inside CUNA the Working Group GL5 “ Engines fuelled by gaseous fuel and relative systems and services” that deals with the development of Normatives connected with the functioning of the motopropulsor group of the street vehicles and autovehicles and their relative components, with reference to the problems related to the use of gaseous fuels and GPL” is active. Through GL5, CUNA follows the activities of the ISO/TC22/SC25 Subcommittee. CTI – Comitato Termotecnico Italiano ( Italian Thermotechnical Committee)

CTI is associated to UNI and deals with Normative and Unification activity in the thermotechnical sector; it had activated a Consultant Group inside SC02, the GC06, dedicated to Hydrogen Technologies. The GC06 embodies representatives of Ministers, Enterprises and Universities. The activity aims at the elaboration of National Regulations in the fields of production, storage, transport


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and use of hydrogen. The Consultant Group GC06 is active in the international field as ISO/TC197 Member “ Hydrogen Technologies”, representing the Mirror Committee in Italy. As TC/197 Mirror , the Members of the GC06 carry on, among others, the following activities:

o Participation, through its accredited national experts, to the following technical

organisms:

• ISO/TC 197/ ad-hoc WG “Hydrogen components” • ISO/TC 197/WG6 “Gaseous hydrogen and hydrogen blends – Land vehicle

fuel tanks” • ISO/TC 197/WG 9 “Hydrogen generators using fuel processing technologies” • IEC/TC 105 (liaison) “Stationary fuel cell power systems – Safety”

o Translation of the ISO/TR 15916 15916 “Basic considerations for the safety of

hydrogen systems”, comments among participants and beginning of the adoption procedure in Italy by UNI.

o Comments to CD, DIS and FDIS produced by ISO/TC 197, and even to analogous

documents of TC in Liaison with TC 197

o Distribution of an informative questionnaire among Italian enterprises operating in the field, in order to present a Report on Hydrogen Survey at the ISO/TC 197 Secretariat for Italy

o Information collection and discussion about the Italian contribution to the ISO/TC 197

Business Plan

CEI – Comitato Elettrotecnico Italiano (Italian Electrotechnical Committee)

CEI is recognised by the Italian Government and by the European Union the technical regulations in the electrotechnical, electronic and telecommunications fields. CEI deals with the ISO/TC22/SC21 Subcommittee activities concerning the electrical vehicles systems and components. The Subcommittee deals with the fuel cells and their electrical components too.

CENTRAL TECHNICAL – SCIENTIFICAL COMMIITTEE (CCTS)

The CCTS (Central Technical – Scientifical Committee) sees the participation of more Ministers ( Infrastructures, Internal, Transports, Environment,…), along with representatives coming from industry and Trade Unions. In 2003, in order to develop technical indications for the approval of a hydrogen refuelling station, in the CCTS Framework a Working Group “Hydrogen” had been constituted, with the aim of developing a guideline as a sort of Regulation.

This Working Group “Hydrogen” is directed by the General Director of the Fire Brigade Dr. Ing. Fabrizio Ceccherini. After completing the work on the refuelling station, CCTS had kept active the Working Group “Hydrogen” in order to answer to other different requests of technical indications coming from other people interested in the homologation of systems or components concerning the


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hydrogen system. Among the first works that had been assigned to the Group, there is the redaction of a technical guideline for the homologation of hydrogen systems for vehicles. The document that had come out from this work could acquire a legal value in the near future. In this sense, this document could be used by the Fire Brigade as a technical base for helping them to give their approval or not for the homologation of a hydrogen vehicle.

Industry

Ministers (Internal,

Infrastructure, Transports,...)

Trade Unions

Universities and

Research

Centres

CCTS Central Technical Scientifical

Committee

Guidelines of

Refuelling

stations

Guidelines ”Hydrogen vehicles”

Guidelines

”. . .”

” Guidelines “Distribution and transportation

Working Group HYDROGEN

Fig. 6.41 – Role and activities of the WP HYDROGEN in the Committee The draft of Regulation had been elaborated considering the principal existent Regulations, Standards and Technical Normatives developed by the International Organisms that deal with Standardisation and Normatives ( ISO, CEN, ECE – ONU). In particular, the following documents had been considered:

• Draft of ECE-ONU Regulation concerning the homologation of vehicles fuelled by compressed gaseous hydrogen;

• ECE-ONU R. 110 Regulation concerning the homologation of vehicles fuelled by natural gas and the related components of the fuelling system

(document valid for the Minister of Infrastructures and Transports since 2002);


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• ISO Standard 11439 “ Gas cylinders – High pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles”;

• Draft of ISO STANDARD ISO/DIS 15869 “Gaseous hydrogen and hydrogen blends – Land Vehicle fuel tanks”.

The editing of such documents can’t be considered an alternative to the work of the big international Groups ISO and ECE-ONU. Actually, the Working Group activity aims at elaborating a document that could constitute a reference guide for the homologation of prototypes and fleet of hydrogen vehicles in Italy in the short term.

With regard to the technical contents of the documet, with reference to the Regulations under study by the GRPE and the European Commission , the main ones are the following:

• Technical features of components as prescribed by the draft of ECE-ONU Regulation R-xx

• Technical features of cylinders as prescribed by the draft of ECE-ONU Regulation R-xx except for:

• Modifications to the requisites of the permeable test of TYPE 4 cylinders ( standard specifications HGV2-USA)

• Modifications to the requisites of life time test (standard specifications HGV2-USA) • Little modifications to the requisites of the explosion test • Annual inspection of periodical riqualification of conformity to the ISO STANDARD

19078 “Gas cylinders — Inspection of the cylinder installation, and requalification of high-pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles”

6.5.14 Inspection procedures as single prototypes (in Italy) Waiting for the publication of the International Regulations for the homologation of vehicles fuelled by pure hydrogen or blends of hydrogen and natural gas, in order to realise some pilot fleets to be tested on the street, it is possible to execute the vehicle’s inspection as a single prototype. The procedure for the obtainment of the Certificate of Approval by the Minister of Transports and the successive release of the vehicle’s registration plate begins with a technical report (see the following scheme).

Inspection test demand (CPA – Minister of Transports)

Technical Report

Vehicle description

Nulla Osta Vehicle Manufacturer

Tests requested by the Manufacturer

Risk Analysis (RAMS)

Inspection tests

Approval and Registration plate

Fig. 6.42 – Scheme of the homologation procedure


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In order to obtain the certificate of approval of a conversion of a vehicle and so its registration plate, the inspection of a single prototype must be undertaken at the competent centre of tests on Vehicles that asks for the following documentation:

o Inspection test demand with the vehicle telaio number indicated, with the attached documentation of payment of the taxes

o Technical Report with the indicated automotive frame of the vehicle that must be inspectioned on the frontispiece , with the stamp on it and signed by an Engineer belonging to the Engineers’ list .

The Technical Report must contain the description of the vehicle and its specific components; furthermore, it must contain the risk assessment taken over for the most critical components underlining the types of brakes, the possibility of their verification and their impact on both the passengers and the other vehicles on the street.

o Visura signed on every sheet with a Declaration of the Representative of the Enterprise that had taken over the conversion

o Permission for the transformation released by the Manufacturer of the original vehicle

The functionality and the security tests that will be done have to be stated with the CPA. Without official Regulations for the homologation of the vehicles fuelled by CH4/H2 blends, the TRANS/WP29/GRPE/2004/03 document is the reference for compressed hydrogen.

After the inspection, if the result is positive, the vehicle registration can be taken over giving to the Motorisation Provincial Office the following documentation, in order to get the circulation booklet and the registration plate.

o Conformity CEE Certificate of the Manufacturer (Declaration for the registration number (COC))

o Declaration Conformity or Origin Declaration, by the society that had done the modifications to the original vehicle with the new series number on it

o Approval Certificate released by CPA containing the technical information of the vehicle and the results of the inspection tests.


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6.5.15 Risk analysis (RAMS) The technical report that illustrates the functional characteristics of the vehicle to be inspectioned must contain a RAMS analysis (Reliability Availability Maintenance and Safety) that could demonstrate the security degree of the vehicle itself on the street, underlining the solutions that had been undertaken both as security disposals and operational procedures that the user must follow strictly. Since the vehicle is not homologated, it can’t be put in the hands of a user without giving him the proper instructions for its use and teaching him the security aspects. Here after the various analysis steps relative to the RAMS procedure are illustrated: Functional diagram of the vehicle and systems/subsystems/components that constitute the added part, not belonging to the series vehicle, object of the experimentation Detailed Functional specifications of every component that specify the functioning mode and the operational and environmental conditions. FMECA (Failure Mode and Effect Critically Analysis) detailed analysis linked to the brakes modes and their effects on both the system and the vehicle and the possible proceedings to avoid the consequent damns. FTA (Fault Tree Analysis) analysis through the “breakdown tree of the overall system under specific tests with the evidence of the TOP EVENTS (vehicle brakes) and MCS (minimum number of brakes at components level( in order to assure the vehicle’s safety seriously. Risk analysis on the possible causes of accidents, linked to eventual human mistakes in the use of the vehicle, evaluating the consequences on the driver , on the passengers and on other vehicles or pedestrians on the street. In this case a graduated scale of the gravity of an eventual accident is given too. Minimum Preventive manteinance in order to keep the best efficiency of the vehicle, substituting the components that present a brake risk before they effectively brake . This action is particularly taken over for the components that had resulted critical in the FMECA and FTA frameworks. Operability analysis : it is defined on the basis of both the functional characteristics of the vehicle and on the results of the risk analysis. This RAMS analysis gives to the Homologation body the most detailed framework on the safety degree of the vehicle during its operation and constitutes a valid help for the Homologation Regulations.


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6.5.16 Hypothesis of a test plan for inspection in Italy Considering the experiences that are ongoing in Italy for the homologation of hydrogen vehicles, and considering the similarities to the vehicles fuelled by blends of methane and hydrogen (derived from the version of the same homologated vehicle) here after a possible list of tests that could be done as inspection activities as a single prototype of such a kind of vehicle is reported:

1. Brakes system: referring to the actual Normative, in case of mass modification of the original vehicle, brakes tests will be taken over ( to be agreed with CPA) in order to verify the performance of the brakes system;

2. Electromagnetic compatibility: EMC characterisations will be taken over for the

evaluation of the system’s response in terms of Immunity and Emission;

3. Consumptions and Emissions: Some characterisations on the roller bench for an urban and extraurban cycle (ECE and EUDC) will be conducted in order to evaluate its performance in terms of consumptions and emissions;

4. Driven distance: the Minister of Transports (CPA) could request the definition and

realisation of 2000 km on the street; the vehicle, with the instruments on board for the characterisation of the principal measures (pressures, temperatures, etc…) will be subjected to a driving plan that will include both urban and extraurban steps.

5. Identification of hydrogen losses in some areas of the vehicle: verification test of

the functionality of the hydrogen losses sensors ( hydrogen sensors, actioning and control systems).

6. Verification of conformity of the vehicle and its components to the tests foreseen by

the drafts of National and International Regulations for hydrogen vehicles.


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6.5.17 Conclusions The results and information contained in this study bring to the following considerations: o The vehicle fuelled by blends of hydrogen and methane till hydrogen percentages

up to the 30% by volume denotes some advantages in terms of a reduction of the urban pollutants ( THC, NOX, CO) and CO2;

o The conversion of an original vehicle fuelled by methane doesn’t present big difficulties even considering the necessity of a proper characterisation of both the carburation system and the spark advance angle, mainly during the transients on the street. Some problems could be encountered thinking about the compatibility of some materials with hydrogen and about the possible hydrogen losses because of the use of engine components suitable for pure methane;

o The refuelling of the vehicle wouldn’t present big difficulties because some refuelling stations for the blends of hydrogen and methane do exist;

o The cylinders for the blends of hydrogen and methane don’t constitute a problem even if they had been constructed for pure methane. Nevertheless, specific cylinders could be used, yet available;

o The inspection of pure methane vehicles (homologated for pure methane) converted to blends up to the 30% of hydrogen by volume would’t present any difficulty but the Homologative body must receive a specific RAMS analysis for the determination of the accident risk;

o For the moment , the use of vehicles converted to the blends of hydrogen and methane as fuel must be limited to fleet tests and these fleets must be managed by specific bodies while waiting for official homologation Regulations.


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6.6 WP6 - Interviews to different key players about barriers and constraints 6.6.1 Results of the interviews The WP6 had been developed by one of the two German partners, the Kompetenz und Innovationszentrum Brennstoffzelle during the first six months of the project. The interviews that had been taken by Dr. Bernard Schaible in order to discover the major barriers for the penetration of hythane on the market, were addressed to the following key players:

Bus and truck manufacturers Natural gas suppliers Fleet operators State Authorities

In particular, here is the list of the Industries and Institutions that had been conducted for the enquiry:

- DAIMLER CHRYSLER; - GVS ( Regional Gas Supplier and fleet operator); - Stuttgarter Strassenbahnen ( Stuttgart Public Transport Company); - State Authorities ( Ministeries for Environment, Traffic and Economic Affairs); - Engler – Bunte – Institute, Gaswärme – Institut Information about Regulations, gas

quality) From the bus and truck manufacturer’s point of view the major barriers are the following:

• Additional expenses ( engine modifications, anti-knock properties, materials,…) are not rewarded by the market;

• The tax reduction related to the construction of gas buses in Germany will end in 2015;

• Additional hydrogen lowers the vehicles range; • Hydrogen is too valuable to be burned ( its use in fuel cell is more convenient(; • Hydrogen, if produced from natural gas, is not cheaper than natural gas.

From the Natural Gas supplier’s point of view the major barriers are the following:

• Gas is paid according to its calorific value ( no extra bonus for the blends); • Hydrogen is too expensive for everyday use (mostly heating); • Investment and running costs for onsite blends at the filling station are high (plus swatch lock fittings); • Demand from gas stations is low , for blends it would be even lower; • Natural Gas has to meet Regulations (German worksheet G260)

From the Public transport company’s point of view the major barrier is the following:

• No interest in gas buses ( low range, cumbersome filling process)


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From the Fleet operator’s point of view the major barrier are the following:

• Blends will only be used at lower price per calorific value • Blends should have the same price of natural gas taking into consideration other

benefits ( i.e. lower emissions, Regulations,…) Finally, the State Authorities that work for the Environmental and Traffic Departments showed an interest in the subject even if the use of H2/NG blends is not in the Agenda in Germany yet. Summing up the results that had come out from all the interviews the major barriers can be grouped under different classes, as follows:

• Technical barriers; • Economical barriers; • Ecological barriers; • Normative barriers.

The most difficult barriers that had to be overcome are the normative barriers and the economical barriers, while the technological barriers and the ecological barriers can be overcome more easily. If neither fuel cell buses nor heavy-duty hydrogen internal combustion engines are yet commercially available, the bridge technology appears to be a blended fuel of hydrogen and CNG that lowers natural gas’ emissions and creates a ready-market for renewable hydrogen. The ecological barriers can be overcome or limited if we think to use hydrogen coming out from chemical industries as a waste subproducts like in the North of Italy (Brescia and Porto Marghera are two examples) where there is a lot of Hydrogen that is actually burned for local heating at the moment, with very low efficiencies. The economical barriers come out when we must think to produce hydrogen and use it in a blend with natural gas. The production of hydrogen from fossil fuels or water electrolysis is still expensive. New methods of hydrogen production or a consistent increase in hydrogen demand could help to limit these kinds of barriers. The most critical barriers are those ones linked to the actual absence of regulations for the use of H2/NG blends. There are regulations for natural gas and in some countries (like Germany) there are approved regulations for the use of pure hydrogen, at least for automotive applications. In Italy the regulations for H2/NG blends are now starting to be developed in parallel with those ones for the use of pure hydrogen. This study is the topic of WP5 that had started in the first six months but not finished yet. At the moment in Italy there are some standards (ISO standards) concerning hydrogen vehicles and UN-ECE/UN-GTR procedures on which different technical Committees (Italian CTI, CUNA, CEI,...) are working in order to let them be approved. It will take a lot of time since at the moment there is just one technical regulation concerning the hydrogen filling stations that had been approved yet.


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6.7 WP7 - Lab tests on the components of the Austrian SOFC to study the ageing processes due to the use of the H2/NG blends Solid Oxide Fuel Cells (SOFCs) used with different blends of gas had been investigated with a scanning electron microscope (SEM) and a non-contact scanning force microscope (AFM).

6.7.1 Samples The cells had been tested by the group of Prof. D. Meissner at the Upper Austrian University of Applied Sciences, Wels, and had been sent to the University of Esslingen after being tested. Blends of methane and hydrogen with different amounts of water added had been used. The determination of their performance measured in Wels had been compared with the results of SEM and AFM investigations of the catalyst layers. The investigation had focused on the anode. The cells had contained an Yttria-doped Zirconia cermet with 5% CeO as anode and a Lanthanum-Strontium-Manganite cathode on an Yttria-doped Zirconia electrolyte (YSZ). The anode contact had been realized by using a Nickel mesh, while cathode had been contacted via a silver wire and had been fixed with silver ink.

6.7.2 Preparation Sample preparation had been done by embedding the cells in polymer matrix or fixing them directly on a sample holder. Some parts of the cells had been removed to enable measurements of the anode and cross sections through electrolyte and electrodes. Before taking over the measurements with the SEM, the samples had been coated by a sputter coater with a thin Gold/Palladium layer to avoid charging. Secondary electron images showing topography and back-scatter-electron images showing the distribution of light and heavy elements had been performed as well as energy-dispersive X-ray fluorescence measurements to determine the elementary composition.

6.7.3 Results SOFC fuelled with dry methane The formation of hydrogen from methane or the direct oxidation of methane may cause a formation of carbon, as had been pointed out in the Report of WP4. The expected contamination of the anode had been proved by SEM investigations. The images clearly show that the whole catalyst surface is covered with a layer of amorphous carbon with fine carbon fibers in between. Large Nickel agglomerations in the carbon layer had been documented as well as fine Nickel crystals at the end of the carbon fibers. Fig. 6.43 shows the surface topography of the anode. Adhesion and stiffness of the contamination layer had been measured by atomic force microscopy (Fig.6.49). These measurements had led to the same conclusion as the SEM analysis. Similarly to the anode , the Nickel mesh had been completely covered by carbon. Cross section images had proved that carbon formed a dense layer with a thickness of more than two micrometers, as shown in Fig.6.45. Cross section images of the Lanthanum-Strontium-Manganite cathode had showed that the cathode consists of two layers of different density (Fig. 6.44). Partial diffusion of Lanthanum through the silver contact layer had been documented.


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It can be concluded that the contamination with carbon layers causes a decrease of the catalyst efficiency due to inhibited gas-catalyst-contact. Due to the formation of carbon fibrils a part of the nickel can be found on top of the fibrils and it is thereby no longer situated on the catalyst surface. In addition, the bad contact between catalyst, gas, and Nickel mesh can hinder the electron exchange and therefore decrease the performance of the SOFCs. Nickel agglomeration indicates a partial degradation of the catalyst.

SOFC fuelled with dry methane/ hydrogen blend A SOFC fuelled with dry hydrogen and an increasing amount of methane had been compared with a SOFC that had been prepared like the other cells (reduced with hydrogen before testing) but it had not been used in a performance test. In a cell used with a methane content up to 20 % in the dry hydrogen no visible carbon contamination of the anode had been detected. Fig. 6.46.a and 6.46.b show a cross section through the anode and the electrolyte. Only minor changes in size and distribution of the crystals had occurred. Although, this cell had been regenerated and in addition during cooling down the sealing leaked significantly. This may be the reason for the lack of carbon contamination. As a comparison a similar cross section as in Fig. 6.46.a and 6.46.b are given in Fig. 6.47.a and 6.47.b. Some parts of the cathode consist of areas with a size of several micrometers where Lanthanum-Strontium-Manganite forms a dense solid phase within the porous layer consisting of small crystals (Fig. 6.48). In case of an increasing solidification after longtime use of the cell this might cause a decreased permeability. SOFC fuelled with methane/ hydrogen blend and 66.6 vol.-% water Feeding but the SOFC with additional water caused no formation of a carbon layer. Nevertheless the performance had been unsatisfying, as had been mentioned in the report of WP4. Probably the reoxidation of nickel to NiO which is accompanied by an increase in volume had caused a delamination of the anode and the formation of gaps. An increased porosity may lead to a decrease in the three-phase-zone and thereby decrease the reactivity.

6.7.4 Conclusions

Both the work of the Research Group of the Upper Austrian University and the SEM and AFM analysis had shown that running SOFCs with pure methane causes a severe carbon contamination of the cells, which leads to drastic losses of performance. Using methane/hydrogen blends with the addition of water, carbon contamination could be avoided or reduced to invisible amounts of carbon although accompanied by a decrease of performance. The addition of water allows to run the cells with higher concentrations of methane and at a higher temperature. Nevertheless, even if a contamination with carbon hadn’t been noticed, physical changes of the anode had occurred (delamination, cracks) influencing the constancy of performance. Investigations by SEM had provided useful information to see the changes of the anode and help to explain the results of performance measurements. All the results emerging from the SEM investigations had been sent to the group of Prof. Meissner at the Upper Austrian University of Applied Sciences, Wels.


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80

Fig. 6.43: SOFC’s anode fuelled with dry methane. Amorphous carbon layer and carbon fibres are mixed with Nickel agglomeration (bright). Fine bright spots at the end of carbon fibres indicate Nickel crystals.

Fig. 6.44: Cross section of SOFC fuelled with dry methane. The two cathode layers of different density are marked by arrows. (Bright spots in electrolyte are detached particles of cathode that stick at cross section after removing parts of the cell.)

Silver contact >

< cathode layer of lower density

< dense cathode layer < electrolyte


BONG-HY – FINAL REPORT – MARCH 2007 81

Tab. 6.45 : SOFC fuelled with dry methane. Material contrast image of cross section through Nickel mesh and carbon contamination

Fig. 6.46a: SOFC fuelled with dry methane/hydrogen blend, cross section through anode and electrolyte. No carbon contamination is visible.


Fig. 6.46b : Details of Fig. 6.46a, showing size and distribution of the catalyst crystals


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Fig. 6.47a: Prepared but not tested SOFC. Cross section through anode and electrolyte.



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Fig. 6.47b: Detail of Fig. 6.47a, showing size and distribution of catalyst crystals

Fig. 6.48 : SOFC fuelled with dry methane/hydrogen blend, cross section through cathode and electrolyte. A solid phase of several micrometers size had formed in catalyst layer.

Lanthanum-Strontium-Manganite cristals

solid phase

electrolyte


(b) Stiffness of the surface dark = soft material

(c) Adhesion forces with the surface bright = high adhesion forces

(a) Topography

Fig. 6.49 : AFM Measurement with (a) topography, (b) stiffness, (c) adhesion of the surface


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6.8 WP8. Diffusion of results and preparation of new proposals

The promotion of REGINS had started at the beginning of the project with the distribution of hundreds of brochures of BONG-HY both in Brescia and in Bologna during international meetings and events concerning new technologies in the energetic sector. A first Conference had been held in Stuttgart on the 19th of June 2006, where the first results coming out from the Italian and the German work had been exposed. In November 2006 some tv interviews had been taken along with the publishment of different articles on local newspapers of Brescia with the first results of the project. In particular, on the 6th of November a first interview of Dr. Maria Chiesa ( Researcher of the Catholic University of the Sacred Heart – Dept. of Brescia) and Dr. Ettore Brunelli (Environmental Councillor of the Municipality of Brescia and BONG-HY project leader) had been taken on the local tv “TELETUTTO” ( program “Cattolica e Dintorni” at 22.30 p.m.). On the 11th of November the newspaper “Il Giornale di Brescia” had published a long article that stressed the environmental and energetic benefits due to the application of the blends of hydrogen and natural gas in light duty vehicles, as it had emerged from the tests made in the BONG-HY framework. Two days later (on the 13th of November) a Press Conference had been held in the Municipality of Brescia with journalists of different local newspapapers to stress the importance of the blends as a “bridge technology” towards the use of pure hydrogen for mobility applications. On the 14th of November a second article had come out on the local newspaper “BresciaOggi” with the summary of the speeches of the local administrators of the Municipality of Brescia,a representative of the industry ASM SPA and a researcher and a professor of the Catholic University of the Sacred Heart. On the 16th of November a final workshop had been taken in Brescia, organised by the Municipality of Brescia with the support of ASM SpA and the Catholic University of the Sacred Heart of Brescia. This international workshop had seen the participation of all the official partners of BONG-HY that had reported their final results and proposed new ideas in order to continue their collaboration. On the 16th of November at 12.00 a.m. another interview of Dr. Maria Chiesa and Dr. Ettore Brunelli had been taken on the TV news program on the Lombardy Region channel RAITRE. On the same day (at 8.00 p.m.) on the local channel “TELETUTTO” in Brescia the TV news program had reported some parts of the presentations of the public administrators and researchers taken at the final workshop of BONG-HY had been held in the same morning. After the end of the project (30th November 2006) different articles and/or abstracts had been written by the project partners, especially by the Lombardy Region and Austrian partners. These articles will be published on scientific journals in the near future or will be reported as “Conference Acts” after the Conferences all over the world where the results contained in them will be divulgated in public. Concerning the Lombardy Region, here are the articles/abstracts that had been produced:

1) A. Iacobazzi, M. Chiesa, A. Genovese, E. Rossi - “Use of blends of hydrogen and natural gas in urban vehicles in the transition towards an hydrogen economy”, 2WIH2/19-21 March 2007 – Ghardaϊa – Algeria;

2) G. Pede, E. Rossi, M. Chiesa, F. Ortenzi – “Test of blends of hydrogen and natural gas in a light duty vehicle”, JSAE ( Journal of Society of Automotive Engineering);

3) S. Cordiner, V. Mulone, R. Scancelli – “Numerical Simulation of engines fuelled by hydrogen and natural gas mixtures” – JSAE 20077317 (Journal of Society of Automotive Engineering);

4) A. Iacobazzi, G. Pede, E. Rossi, M. Chiesa, F. Ortenzi – “Bench testing of blends of hydrogen and natural gas in vehicles for urban duties” , WEC 2007;

5) A. Iacobazzi, M. Chiesa, S. Cordiner, F. Ortenzi – “Blends of hydrogen and natural gas in urban vehicles” , HYPOTHESIS VII – 27-30 March 2007, MERI'DA (MEXICO)


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Concerning the Upper Austria Region, the University of Linz,with the collaboration of the University of Leoben, had written the following paper that will be presented at the International Conference of Clean Electrical Power ( ICCEP 2007) that will be held in Capri on the 21st-23rd of May: “Operating micro-tubolar SOFC’s containing nickel based anodes with blends of methane and hydrogen” – G. Buchinger, T. Raab, S. Griesser, W. Sitte, D. Meissner – 21st - 23rd of May, IPPEC 2007. At the end of the project a dedicated website had been created at the following address: www.dmf.unicatt.it/bong-hy This website aims at describing the principal objectives of the project and contains all the scientifical results of BONG-HY. Actually, from the website it is possible to download all the documents (mainly articles, intermediate and final reports, presentations,…) produced by the different project partners and their external experts. On the website it’s even possible to find the personal contacts of all the project partners and their external expertise for people that want further details of the project or establish future scientifical collaborations. For example, on the following website: www.fh-ooe.at/campus.wels/forschung-entwicklung/projecte.html a synthetic description of the project will be uploaded very soon. The website has different links to the project partners websites and the project partners will introduce a link to the BONG-HY website themselves. Concerning the elaboration of new proposals, a future collaboration can start between the Italian partners and the Swedish Gas Centre of Malmo that is taking over experimentations of blends of hydrogen and natural gas on urban buses in Malmo


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7. POSSIBLE FUTURE DEVELOPMENT In the Brescia territory different operators representative of both the components and public services sectors are present; these operators are very sensible to the evolution of the energetic technologies. In particular, AIB (Association of Industrial operators of Brescia) has just created a local Consortium whose acronym is CRAMER with a lot of its associates, the Scientific Universities of Brescia, ASM SPA and the Municipality of Brescia (partner leader of Bong-hy) having as main objective the study and experimentation of sustainable technologies, focusing even on the ones that concern the introduction of hydrogen in the energetic system. It’s important to note that ASM SPA (see www.asm.brescia.it), one of the leader energetic companies in Italy that services all the city of Brescia and most of the Province (e.e., DH, waste collection, n.g. distribution, water captation and distribution), had always been in the van in the energetic field focusing much of its attention on the environment so that it started the project of district heating and cogeneration since 1971 and the waste-to-energy plant since 1998. Since year 2003 the waste-to-energy plant had been implemented because of the construction of a third combustion line, entirely due to the biomasses’ combustion, generating electricity and heat with an almost null balance of atmospheric carbon dioxide emissions. In this context, stating that hydrogen is actually seen as the “sustainable” fuel of the future, ASM SPA and other industries that belong to AIB are considering the introduction of this innovative energetic vector in the Brescia territory for both mobility applications and stationary applications for the cogeneration of electricity and heat. An ulterior (further) aspect that must be taken into consideration is the presence on the territory of a chemical industry (CAFFARO) that throws away as a coproduct a quantity of pure hydrogen variable from 2.000.000 to 6.000.000 cu. meters every year, thanks to electrolytic processes. The Consortium is based on a legal Agreement among the different partners (the local Universities, the Municipality of Brescia and other local industries) and it has been already signed by all the legal representatives so that the collaboration stated by the Agreement has already started. At first, the Consortium will focus its attention on the projects that are taking place on the territory at the moment giving strenght to them with the involvement of all the local industries that could be interested in the single projects and then it will start to develop new projects that could lead to a technological innovation in the local industries. The ideas contained in the BONG-HY project had come out from a collaboration between the Department of Mathematics and Physics of the Catholic University of Brescia and the National Centre of Research for the Environment, the Energy and the New Technologies (ENEA) and the workpackages of the project had been already discussed since at least two years ago with different local industries (ASM SPA in primis) showing a great interest in following the possible experimentations that could have taken place on the basis of the theoretical expectations.


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The results of BONG-HY could open the path to a long term scenario of a new energetic system for the city of Brescia that considers the ASM SPA fleet of waste collecting vehicles (side-loaders) entirely fuelled with hydrogen. Considering the average pace of this particular type of vehicle (stop and go drive due to the lift and unloading of the waste bins), considering that a fuel cell is more efficient than an internal combustion engine for short to mid powers and, viceversa, it is less efficient when the engine works at full power, for these vehicles the use of PEM (proton exchange membrane) fuel cells fuelled with pure hydrogen is foreseen in a long term vision. Nevertheless, this long term vision requires some infrastructures linked to hydrogen production, storage and distribution whose realization necessitates both a longer time interval and an hydrogen demand not limited to the support of pure experimentations of its use on prototypes of vehicles but that could represent one of the fundamental and necessary “stones” for the construction of the entire final system of energetic sustainable development of Brescia. In a short to mid term scenario the evolution to an hydrogen economy could be represented by the use of “ intermediate fuels” among which the most promising seem to be the blends of natural gas and hydrogen for their use in the automotive sector. The use of such blends will both bring to a great improvement of the air quality in urban areas and to the development of the hydrogen technologies locally (components, vehicles, refuelling stations, assistance and maintenance services..) in a gradual manner and with limited investments. The present project named BONG-HY represents the first part of theoretical-experimental test of the real potentialities linked to the use of blends of natural gas and hydrogen; the project is the first step of a wider program that foresees the introduction of these technologies in the energetic system of Brescia. The local presence of industrial operators that could enter in the overall technological chain, from the production to the services sector (for example maintenance and assistance services to hydrogen systems) let the activities foreseen in BONG-HY become very interesting to be realized in a short term future for the real opportunities that BONG-HY could give in the field of the sustainable energetic systems.


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8 ATTACHMENTS

Here attached there are one CD and one DVD. The CD contains all the documents and articles related to the diffusion of BONG-HY in different Countries of the world ( most of all Italy, Austria, Germany, Algeria, Japan, Mexico). The DVD contains the registration of the final Conference with the presentations taken by all the project partners and some guests working in the same technical field too. The DVD begins with an interview of Dr. Ettore Brunelli (Environmental Councillor of the Municipality of Brescia and BONG-HY Project Leader) and Dr. Maria Chiesa (Researcher of the Department of Environmental Physics of the Catholic University of Brescia) taken by Dr. Antonella Olivari on the 6th of November 2006 on the local TV “TELETUTTO” (program “Cattolica e Dintorni” at 22.30 p.m.). Unfortunately, it had been difficult for the project partners to be able to get the registration of other TV and RADIO interviews linked to the diffusion of BONG-HY, but the references to these interviews are reported in Chapter 7 .


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