effects of fuel composition and engine load on emissions ... · derived cetane number (dcn) ... dcn...

Fuel and Load effects on HD emissions– Final Report Issue 1, 29th June 2010) Orbital Australia Pty Ltd of 104

Effects of Fuel Composition and Engine Load on Emissions from

Heavy Duty Engines

Final Report

Department of the Environment, Water, Heritage and the Arts

June, 2010

ORBITAL AUSTRALIA PTY LTD


© Commonwealth of Australia 2010

This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney General’s Department, Robert Garran Offices, National Circuit, Barton ACT 2600 or posted at http://www.ag.gov.au/cca

Disclaimer:

The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment, Heritage and the Arts or the Minister for Climate Change and Water. While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication.


CONTENTS

1 EXECUTIVE SUMMARY .......................................................................................10

2 INTRODUCTION....................................................................................................14

3 BACKGROUND.....................................................................................................14

3.1 Australian Fuel Quality Standards ..................................................................14

3.2 Effect of Fuels on Emissions...........................................................................16

3.3 Effect of Regulations and Engine Technology on Emissions ......................19

3.4 Effect of Engine Load on Emissions...............................................................25

4 EXPERIMENTAL METHOD...................................................................................26

4.1 Overview............................................................................................................26

4.2 Engine Selection...............................................................................................27 4.2.1 On-Road Heavy Duty Truck Fleet ................................................................... 30 4.2.2 Selected Vehicle Specifications ...................................................................... 32

4.3 Test Fuels and Management............................................................................32

4.4 Heavy Duty Engine Testing..............................................................................34 4.4.1 Test Cycles Used............................................................................................ 34 4.4.2 Engine Dynamometer(s) ................................................................................. 36 4.4.3 Emissions Sampling........................................................................................ 38

4.5 Development of Alternate Loading Engine Test Cycles................................39 4.5.1 Origin of the European Transient Cycle (ETC)................................................ 39 4.5.2 Vehicle Road Load Estimation ........................................................................ 40 4.5.3 Drive Cycle Simulation Results ....................................................................... 41

4.5.3.1 Transient Test Engine Cycles...............................................................44 4.5.3.2 Steady State (Modal) Cycles ................................................................45

5 FUEL COMPOSITION TEST RESULTS................................................................48

5.1 Presentation and Interpretation of Results ....................................................48

5.2 ADR80/00 Engine Results ................................................................................48

5.3 ADR80/02 Engine Results ................................................................................50

5.4 ADR80/03 Engine..............................................................................................52

5.5 Summary of Fuel Composition Results..........................................................55 5.5.1 Comparison of Low and High Cetane Diesel .................................................. 55 5.5.2 Comparison of Biodiesel Results .................................................................... 58 5.5.3 Low Density Fuel Results................................................................................ 62


5.6 Discussion: Fuel Composition Effects on Heavy Duty Engine Emissions..66

6 LOAD EFFECTS: TEST RESULTS.......................................................................68

6.1 Presentation and Interpretation of Results ....................................................68

6.2 ADR80/00 Engine..............................................................................................68

6.3 ADR80/02 Engine..............................................................................................71

6.4 ADR80/03 Engine..............................................................................................73

6.5 Summary of Load Effect Results.....................................................................76

6.6 Discussion: Load Effects on Heavy Duty Engine Emissions .......................79

7 CONCLUSIONS.....................................................................................................81

8 REFERENCES.......................................................................................................84

APPENDIX 1. FUEL ANALYSIS DATASHEETS.......................................................86 Low Cetane Diesel ........................................................................................................ 87 High Cetane Diesel ....................................................................................................... 89 B5 Diesel ....................................................................................................................... 93 B20 Diesel ..................................................................................................................... 95 R50 Diesel..................................................................................................................... 97 B100 Diesel – used only to prepare B5 and B20........................................................... 99

APPENDIX 2. PRIME MOVER SPECIFICATIONS (EXTRACT ONLY) ................... 101 Prime-mover to suit 70tonne Service .......................................................................... 101 Prime-mover to suit 100tonne Service ........................................................................ 103


ACRONYMS ADR Australian Design Rule ADR80/xx Either ADR80/00, ADR80/02 or ADR80/03 B0 Diesel with 0% Biodiesel content B5 Diesel with 5% Biodiesel content B20 Diesel with 20% Biodiesel content CH4 Methane CO Carbon Monoxide CO2 Carbon Dioxide CI Cetane Index as per ASTM D4737 Procedure A [1] CUEDC Composite Urban Emissions Drive Cycle DCN Derived Cetane Number as per ASTM D6890 [2] DEWHA Department of the Environment, Heritage, Water

and the Arts Diesel CUEDC One of CUEDC types developed under the Diesel NEPM Preparatory

Projects Diesel NEPM Diesel National Environment Protection Measure DPF Diesel Particulate Filter E-OBD European – On Board Diagnostics EGR Exhaust Gas Recirculation EMS Engine Management System ESC European Steady Cycle (13-mode test cycle) ELR European Load Response (test cycle) ETC European Transient Cycle (test cycle) FIGE Forschungsinstitut für Geräusche und Erschütterungen (now TUV) GCM Gross Combination Mass GVM Gross Vehicle Mass HC Hydrocarbons NO Nitric Oxide NO2 Nitrogen Dioxide NOx Oxides of Nitrogen (consisting of NO2 and NO) NMHC Non-Methane Hydrocarbons (THC minus CH4) PM Particulate Mass PM2.5 Particulate Mass with diameter less than 2.5micrometer (μm) PM10 Particulate Mass with diameter less than 10micrometer (μm) ppm parts per million R50 Diesel with 50% Renewable content SAE Society of Automotive Engineering THC Total Hydrocarbons (including methane) VGT Variable Geometry Turbocharger


List of Tables Table 1.1 – Summary of Fuel Effects on Heavy Diesel Engine Emissions ______ 12 Table 3.1 – Australian National Fuel Standards for Automotive Diesel [3] ______ 15 Table 3.2 – Summary of Emission ADR History for Diesel Vehicles___________ 22 Table 3.3 – ADR Test Requirements for On-Road Heavy Duty Diesel Engines__ 25 Table 4.1 – Test Engine Specifications_________________________________ 28 Table 4.2 – Estimated Australian HDV Engine Usage (Orbital’s estimate based on

marketing information, 2006) _______________________________ 30 Table 4.3 – Kenworth Articulated Truck Specifications_____________________ 32 Table 4.4 – Project Fuels Properties___________________________________ 33 Table 4.5 – Selected Parameters for the FIGE Cycle ______________________ 40 Table 4.6 – 70t and 97t Steady State Tests _____________________________ 46 Table 7.1 – Summary of Fuel Effects on Heavy Diesel Engine Emissions ______ 82

List of Figures Figure 3.1 – Effect of Biodiesel on Heavy Duty Engine Emissions ____________ 17 Figure 3.2 – Confounding Effect of Fuel Density and Cetane Number on Emissions

______________________________________________________ 18 Figure 3.3 – Confounding Effect of Fuel Density and Aromatic Content on Emissions

______________________________________________________ 19 Figure 3.4 – Influence of Fuel properties on Heavy-Duty Diesel Emissions [9] ___ 19 Figure 3.5 – Overview of Emission ADRs for Diesel Vehicles ________________ 23 Figure 3.6 – Overview of Heavy Duty Vehicle European (Euro) Regulation Limits 23 Figure 3.7 – Overview of International Heavy Duty Vehicle (HDV) Emission Testing

Trends ________________________________________________ 24 Figure 4.1 – Engine Test Sequence____________________________________ 27 Figure 4.2 – ADR80/xx Heavy Duty Diesel showing Typical Engine Features for this

Class of Engine _________________________________________ 29 Figure 4.3 – ADR80/03 level Exhaust Aftertreatment System, as fitted to a Heavy

Duty Diesel Engine_______________________________________ 29 Figure 4.4 – Heavy Duty Vehicle Manufacturers Distribution within AT Category _ 31 Figure 4.5 – Estimated Distribution of Engine Manufacturers within AT Category_ 31 Figure 4.6 – ESC Engine Test Cycle (Euro 3, 4, 5) ________________________ 35 Figure 4.7 – ETC Engine Test Cycle ___________________________________ 36 Figure 4.8 – Heavy Duty Engine Facility ________________________________ 37 Figure 4.9 – Heavy Duty Engine Dynamometer Layout _____________________ 37 Figure 4.10 – Partial Flow (Micro) compared to a Full Dilution Tunnel [16] _______ 39 Figure 4.11 – FIGE Vehicle Test Cycle (resultant ETC is shown in Figure 4.7)____ 40 Figure 4.12 – Road Load Estimations ___________________________________ 41 Figure 4.13 – 70t Vehicle Drive Cycles as Simulated________________________ 42 Figure 4.14 – 97t Vehicle Drive Cycles as Simulated________________________ 43 Figure 4.15 – 70t Transient Engine Test Combined Cycle____________________ 44 Figure 4.16 – 97t Transient Engine Test Combined Cycle____________________ 45 Figure 4.17 – Low and High Load Steady State Tests_______________________ 47 Figure 5.1 – ADR80/00 ESC Results ___________________________________ 49 Figure 5.2 – ADR80/00 ETC Results ___________________________________ 49 Figure 5.3 – ADR80/00 Full-Load Torque Curves _________________________ 50 Figure 5.4 – ADR80/02 ESC Results ___________________________________ 51 Figure 5.5 – ADR80/02 ETC Results ___________________________________ 51 Figure 5.6 – ADR80/02 Full-Load Torque Curves _________________________ 52


Figure 5.7 – ADR80/03 ESC Results ___________________________________ 53 Figure 5.8 – ADR80/03 ETC Results ___________________________________ 54 Figure 5.9 – ADR80/03 Full-Load Torque Curves _________________________ 55 Figure 5.10 – NOx Results: Low vs High Cetane___________________________ 56 Figure 5.11 – PM Results: Low vs High Cetane____________________________ 57 Figure 5.12 – CO2 Results: Low vs High Cetane___________________________ 58 Figure 5.13 – NOx Results: Biodiesel vs Diesel____________________________ 59 Figure 5.14 – PM Results: Biodiesel vs Diesel_____________________________ 60 Figure 5.15 – CO2 Results: Biodiesel vs Diesel____________________________ 61 Figure 5.16 – NOx Results: Low Density vs Regular Diesel __________________ 63 Figure 5.17 – PM Results: Low Density vs Regular Diesel ___________________ 64 Figure 5.18 – CO2 Results: Low Density vs Regular Diesel __________________ 65 Figure 6.1 – Load Effects: ADR80/00 Steady State Cycle Results ____________ 69 Figure 6.2 – Load Effects: ADR80/00 Change in Steady State Cycle Emissions _ 69 Figure 6.3 – Load Effects: ADR80/00 Transient Cycle Results _______________ 70 Figure 6.4 – Load Effects: ADR80/00 Change in Transient Cycle Emissions ____ 70 Figure 6.5 – Load Effects: ADR80/02 Steady State Cycle Results ____________ 71 Figure 6.6 – Load Effects: ADR80/02 Change in Steady State Cycle Emissions _ 72 Figure 6.7 – Load Effects: ADR80/02 Transient Cycle Results _______________ 72 Figure 6.8 – Load Effects: ADR80/02 Change in Transient Cycle Emissions ____ 73 Figure 6.9 – Load Effects: ADR80/03 Steady State Cycle Results ____________ 74 Figure 6.10 – Load Effects: ADR80/03 Change in Steady State Cycle Emissions _ 74 Figure 6.11 – Load Effects: ADR80/03 Transient Cycle Results _______________ 75 Figure 6.12 – Load Effects: ADR80/03 Change in Transient Cycle Emissions ____ 75 Figure 6.13 – Load Effects: Relative Change in Steady State Cycle Results _____ 76 Figure 6.14 – Load Effects: Relative Change in Transient Cycle Emissions ______ 77 Figure 6.15 – Load Effects: Relative Change in Emissions during Urban Phase___ 78 Figure 6.16 – Load Effects: Relative Change in Emissions during Rural Phase ___ 78 Figure 6.17 – Load Effects: Relative Change in Emissions during Motorway Phase 79


DEFINITIONS

Biodiesel Renewable fuel derived from vegetable oils or animal fats through the process of transesterification, which can be used in conventional diesel engines.

Cetane The alkane used as a reference in determining the Cetane Number (auto-ignition quality) of diesel following ASTM D613 [4]. Originally, n-cetane (C16H34) with a cetane number of 100 and 1-methylnaphthalene (C11H10) with a cetane number of 0. Difficulties in handling 1-methylnapthalene and its expense led the ASTM to replace it with iso-cetane (2,2,4,4,6,8,8-heptamethylnonane) as a secondary reference fuel.

Cetane Index (CI)

A calculated estimate of the auto ignition quality of diesel fuels. CI is calculated from fuel density and distillation measurements [1]. Cetane index is not appropriate for diesel containing biodiesel or cetane enhancers since it is calculated using properties of the base diesel fuel.

Derived Cetane Number (DCN)

A measurement of the auto ignition quality of diesel fuels. DCN value is measured in a constant volume chamber, or specifically an Ignition Quality Tester (IQTTM). Higher DCN indicates shorter combustion delays [2].

Diesel Particulate Filter

An exhaust aftertreatment device where particulate matter in the exhaust gas is collected on a filter matrix. Collected PM is then oxidised through regeneration. PM may also be removed during servicing by emptying or replacing the filter.

Dilute is where the emissions sample from the exhaust of an engine is mixed with ambient air to result in a sample of known/controlled mass flow rate. Since the total mass flow rate is known, mass based emissions (such as grams/test or grams/km) can be directly computed from the concentration of pollutants. The pollutant concentration in a dilute sample is lower than that in a raw (undiluted) sample.

EGR Exhaust Gas Recirculation. A controlled proportion of the exhaust gasses are fed back into the inlet manifold. In a diesel engine this generally has the effect of reducing NOx emissions, but at the cost of higher HC, CO and PM emissions.

Integration is the cumulative summation of the modal readings during the test or phase to arrive at a result for the whole test cycle. Integration is used by emissions test procedures such as the ETC.

Modal is the sampling of pollutants on, typically, a second-by-second basis. Modal data allows for the examination of effects due to individual drive events and transients to be examined.

Oxidation (2-Way) Catalyst

A catalyst that when hot uses excess oxygen in the exhaust stream to oxidise pollutants. Hydrocarbons are converted to carbon dioxide and water, carbon monoxide is converted to carbon dioxide. There may also be some reduction in particulate mass due to oxidation to carbon dioxide.


Phase a defined segment of a test, for example the FIGE Drive cycle is split into 3 phases, urban, rural and motorway.

Regeneration

The process of oxidising particulate matter collected in a diesel particulate filter. This can be a passive process, or if this is not sufficient, some diesel engine control systems will activate an active regeneration process.

Passive regeneration: When exhaust temperatures are sufficiently high due to engine operating conditions (high loads and/or speeds for a period of time) particulate matter oxidises to carbon dioxide. DPFs may have a catalytic coating to reduce the temperatures required for this combustion.

Active regeneration: The engine control system takes actions in order to oxidise particulate matter collected in the DPF. This is generally done by artificially increasing the exhaust temperature by late in-cylinder fuel injection, use of a dedicated fuel injector in the exhaust system, or other means of direct heating.

Renewable Diesel

Synthetic diesel fuel that has been refined using renewable feedstocks in addition to (or to substitute) petroleum feedstocks. Renewable diesel is sometimes also known as hydrocracked vegetable oil or hydrocracked tallow.

Variable Geometry Turbo

Exhaust Turbocharger that can adapt to engine operating point. Variable geometry allows potential for a combination of increased boost at low engine speeds and reduced backpressure at high engine speeds when compared to a conventional (fixed geometry) turbocharger.


1 EXECUTIVE SUMMARY

This report outlines the findings of a study commissioned by the Australian Government Department of Environment, Water, Heritage and the Arts.

The aim of the study was to determine whether the different fuels available or soon to be available on the Australian market have an impact on the emissions from the heavy duty engines used in Australia. Of particular interest is the effect of the Australian standard for diesel allowing a cetane index of 46 where the European specification requires a cetane number of 51.

A secondary aim was to understand better the relationship between engine load and air quality emissions, especially particles. As a means of addressing the growth in freight movements, regulatory authorities are moving to increase mass limits for heavy duty vehicles. Whilst additional fees are proposed for the increase in road wear, nothing is known of the impact of the additional mass limits on air quality emissions.

This study was carried out utilising the heavy-duty engine test facility at Orbital Australia. This engine test facility was supported by a grant from the Australian Federal Government with the objective of improving testing accuracy for medium and heavy duty applications to the level required for compliance or certification, complementing light duty facilities with the same capability.

Comparative testing was undertaken using three heavy duty engines of varying emission compliance levels; ADR 80/00 (Euro 3), ADR 80/02 (Euro 4) and ADR 80/03 (US EPA 2007, Euro 5). All three engines were of capacity greater than 12L, thereby representing the engines typically fitted to articulate trucks typically operating with GVM greater than 25 tonne. Both the ADR 80/02 and 80/03 engines use EGR, primarily for controlling NOx emissions. Of the three engines tested, only the ADR 80/03 engine was equipped with a diesel particulate filter (DPF) as part of its exhaust aftertreatment system.

Testing of the nominated fuels was undertaken using the prescriptive methods of ADR80/03; equivalent to Euro 5 with regard to the specification of equipment and protocol. The European Steady Cycle (ESC) and European Transient Cycle (ETC) formed the basis of the comparison.

The five different diesel engine fuels tested were differentiated by their cetane number. However, cetane number is just one of the properties of diesel fuel. With perhaps the exception of additives, changes in cetane do not occur in isolation of the change to other fuel properties such as aromatics and density. This makes it difficult to segregate what effects are due to cetane alone, and which may be the result of a combination of properties.

Table 1.1 summarises the average emission trends in response to the use of the different fuels tested in this study. Rather than give specific results, the table summarises whether a change was observed and whether it was considered real. A marginal response is assigned one + or -. A comparably significant change assigned more than one +/-. If the response is completely within the experimental scatter a ~ is indicated. Given that testing in most cases consisted of only two results per fuel, a robust statistical analysis was not possible.

From an air quality perspective, two questions can be asked:

How does a particular fuel effect engine emissions?

Is a particular engine (and its associated technology) sensitive to a particular fuel?


What Table 1.1 suggests is that the two questions must be considered together since engine technology would appear to have a significant impact on the fuel test outcome. Engine technology refers to the approach the manufacturer has taken in controlling emissions, in particular NOx and PM; the primary pollutants of interest from a heavy duty diesel engine. The engine technology itself may respond differently under steady state and transient conditions, thereby making the emission trends sensitive to the test cycle used to quantify the emissions impact.

Whilst specific differences for the fuel types are detailed in this report, the general trend observed was that for NOx and PM emissions, any changes tended to be larger for the ADR80/00 and ADR80/02 engines than for the ADR80/03 engine. Changes in CO2 emissions observed were slight, but did not appear to be correlated to engine technology.

The ADR80/00 engine represents the oldest technology in this study. This engine had no exhaust aftertreatment (DPF) for management of PM, and nor did it utilise EGR for NOx control.

The ADR80/03 engine represents the newest technology in this study. This engine had an exhaust aftertreatment (DPF) for the post-engine management of PM, EGR for NOx control and a variable geometry turbocharger (VGT) for airflow management.

The ADR80/02 engine represents a mid-way technology, which utilises EGR for NOx control and a variable geometry turbocharger (VGT) for airflow management, but has no aftertreatment (DPF) for the management of PM.

It appears that the use of increasingly sophisticated emissions management systems on modern engines may be improving their robustness to variations in fuel properties. For example, the DPF equipped ADR80/03 engine so significantly reduces the absolute level of PM emissions that the difference in fuel properties is not discernable or perhaps subject to secondary factors such as the condition of the DPF itself. Meanwhile, the older non-DPF engines show a greater PM sensitivity to fuel properties. Similarly, there is evidence to suggest that the EGR and VGT equipped engines potentially mask some of the fuel property effects on NOx emissions. It was noted that NOx emissions were often observed to trend differently when tested over steady state and transient cycles. This characteristic is suspected to be a function of the transient control of the emission systems and thermal soak conditions. Where differences are seen between transient and steady state testing results, the real world effects of the fuel properties could be expected to depend largely on a vehicle’s specific duty cycle.


Fuel comparison

Test Cycle

ADR80/00 ADR80/02 ADR80/03 Overall

ESC NOx +

PM -

CO2 - -

NOx +

PM - -

CO2 -

NOx +

PM -

CO2 -

NOx ▲

PM ▼

CO2 ▼

Diesel Low High Cetane

ETC NOx -

PM - -

CO2 - -

NOx -

PM -

CO2 - -

NOx -

PM +

CO2 +

NOx ▼

PM ▼

CO2 ▼

ESC NOx -

PM - -

CO2 +

NOx -

PM - -

CO2 +

NOx -

PM +

CO2 +

NOx ▼

PM ▼▼

CO2 ▲

Biodiesel

B0 B20

(ignoring B5 which is seen to not always lie between B0 and B20)

ETC NOx +

PM - -

CO2 +

NOx +

PM - -

CO2 +

NOx +

PM -

CO2 -

NOx ▲

PM ▼▼

CO2 ▲

ESC NOx -

PM - -

CO2 - -

NOx ~

PM -

CO2 - -

NOx ~

PM +

CO2 - -

NOx ???

PM ▼▼

CO2 ▼▼

Diesel R50

(R50 is low density synthetic diesel)

ETC NOx - -

PM - -

CO2 - -

NOx ~

PM ~

CO2 - -

NOx ~

PM ~

CO2 - -

NOx ???

PM ???

CO2 ▼▼

ESC NOx yes

PM yes

CO2 yes

NOx yes

PM maybe

CO2 yes

NOx maybe

PM no

CO2 yes

Overall, is engine sensitive to differences in fuel properties?

ETC NOx yes

PM yes

CO2 yes

NOx yes

PM yes

CO2 yes

NOx maybe

PM no

CO2 maybe

Table 1.1 – Summary of Fuel Effects on Heavy Diesel Engine Emissions

Examination of load effects required the generation of steady state and transient engine test cycles representative of the vehicle operation at the nominated 70 and 100 tonne configurations. These cycles were also conducted using the procedural requirements of ADR80/03.

Vehicle GCM was increased from 70t to 97t and operation simulated at the 50% laden condition resulting in an increase in payload by an estimated 27%. This simulated change resulted in an increase to the total engine power output required to follow the specific FIGE vehicle drive cycle by 40-50%*.

The effects of engine load on emissions can be summarised as:

* A change to 100% laden does not proportionally increase the power requirement since the vehicle configuration consists of vehicle mass plus payload.


NOx emissions were found to increase by between 25 and 50%, depending on whether the assessment was undertaken by steady state or transient test cycles.

The effect of increased GCM on PM2.5 emissions was engine and cycle dependant. PM emissions from the ADR80/02 engine more than doubled for most tests with the increased GCM. PM emissions from the ADR80/03 engine also showed a significant increase, though having been fitted with a DPF exhaust aftertreatment the absolute level of the emissions was much smaller. There were only minor effects on PM emissions for the oldest ADR80/00 model engine.

CO2 emissions were found to increase in-line with the power required by the drive cycle


2 INTRODUCTION

The primary aim of the study is to determine whether the different fuels available, or soon to be available, in the Australian market have an impact on the emissions from the heavy duty engines used here. Of particular interest is the effect of the Australian standard for diesel allowing a Cetane Index of 46 where the European specification requires a cetane number of 51.

Engine testing was undertaken to determine if there is a measureable difference in the exhaust emissions as a result of the fuel used. Five fuels were nominated:

Diesel with a Cetane Index and/or Derived Cetane Number (DCN) of 51 (±1)

Diesel with a Cetane Index and/or DCN of 46 (±1)

B5 Biodiesel with a DCN of at least 51

B20 Biodiesel with a DCN of at least 51

Renewable diesel

Since the project scope was to use commercially available Australian fuels, some concession was allowed for low and high cetane fuels outside the nominated values to be procured, providing the cetane difference between low and high diesel fuels was achieved.

For each engine, testing was undertaken by Orbital using the heavy-duty engine test facility at Orbital Australia. Testing was conducted using both steady state and transient cycles.

A secondary aim is to better understand the relationship between engine load and air quality emissions, especially particulates. This need has arisen as a result of proposals to increase road limits on the maximum weight permissible.

The engine load testing first requires the test cycle or points to be determined. This was done by engineering calculation and drive simulation to ultimately provide:

Low and high tare steady state cycles; and

Low and high tare transient cycles

The European Transient Cycle (ETC) is itself derived from a real world vehicle drive trace and similar techniques were used by Orbital to derive suitable cycles for this study.

3 BACKGROUND

3.1 Australian Fuel Quality Standards

The quality of fuel in Australia is regulated by the Fuel Quality Standards Act 2000. The Fuel Standard (Automotive Diesel) Determination 2001 sets out the environmental and operability standards that apply to automotive diesel. This includes cetane index and for diesel containing biodiesel, derived cetane number.


Diesel Standards Parameter National standard Date of effect Test Method

Biodiesel 1 5.0% volume by volume (max)

1-Mar-09 EN 14078

500 ppm (max) 31-Dec-02

50 ppm (max) 1-Jan-06 Sulfur

10ppm (max) 1-Jan-09

ASTM D5453

Cetane Index 46 (min) index 1-Jan-02 ASTM D4737

Derived Cetane Number (of diesel containing biodiesel)

51.0 (min) 21-Feb-09 ASTM D6890

820 (min) to 860 (max) kg/m3

1-Jan-02 Density

820 (min) to 850 (max) kg/m3

1-Jan-06 ASTM D1298

370°C (max) 1-Jan-02 Distillation T95

360°C (max) 1-Jan-06 ASTM D86

Polyaromatic hydrocarbons (PAHs)

11% m/m (max) 1-Jan-06 IP391

Ash 100 ppm (max) 1-Jan-02 ASTM D482

Viscosity 2.0 to 4.5 cSt @ 40°C 1-Jan-02 ASTM D445

Carbon Residue (10% distillation residue)

0.2 mass % max 16-Oct-02 ASTM D4530

Water and sediment 0.05 vol % max 16-Oct-02 ASTM D2709

Water (all diesel containing biodiesel)

200 mg/kg (max) 21-Feb-09 ASTM 6304

Conductivity @ ambient temp

50 pS/m (Min) @ambient temp (all diesel held by a terminal or refinery for sale or distribution)

16-Oct-02 ASTM D2624

Oxidation Stability 25 mg/L max 16-Oct-02 ASTM D2274

Colour 2 max 16-Oct-02 ASTM D1500

Copper Corrosion (3 hrs @ 50°C)

Class 1 max 16-Oct-02 ASTM D130

Flash point 61.5°C min 16-Oct-02 ASTM D93

Filter blocking tendency 2.0 max 16-Oct-02 IP 387

Lubricity 0.460 mm (max) (all diesel containing less than 500ppm sulfur)

16-Oct-02 IP 450

1 The biodiesel component of diesel must meet the requirements of fuel quality standard for biodiesel set out in the Fuel Standard (Biodiesel) Determination 2003.

Table 3.1 – Australian National Fuel Standards for Automotive Diesel [3]

Cetane Number, Derived Cetane Number and Cetane Index are related, but they are not the same. Diesel fuel must have a chemical structure that facilitates auto ignition. The CFR engine is used to define the diesel fuel auto-ignition quality, following ASTM D613 [4]. The approach used references the performance of the fuel being tested to two reference fuels: n-cetane (C16H34) with a cetane number of 100 and 1-methylnaphthalene (C11H10) with a cetane number of 0. Typical cetane numbers are between 40 and 60.


Derived Cetane Number (DCN) is another method of determining the auto-ignition quality of a fuel by measurement of combustion in a constant volume chamber [2], specifically an Ignition Quality Tester (IQTTM). The IQT instrument applies a simpler, more robust approach to cetane number measurement than the CFR engine method. The ignition delay of the fuel is calculated as the time difference between the start of fuel injection and the start of combustion. The derived cetane number for the fuel can then be calculated using an empirical inverse relationship to ignition delay. Cetane Index (CI) is a calculated estimate of a diesel fuel’s cetane number. It is calculated from simple measurements of the fuel [1] which can be taken without the specialised equipment needed for actual or derived cetane number measurements. This allows estimation of the cetane number if testing cannot be otherwise undertaken. It should be noted that cetane index cannot be used for diesel containing biodiesel or cetane enhancers The minimum Cetane Index for Australian fuel, as shown in Table 3.1, is 46, whilst in Europe EN 590 specifies both a minimum cetane index of 46 and a minimum cetane number of 51. The cetane number is the environmental parameter that must be met; whilst the cetane index is for operability to prevent the addition of too much cetane improver to boost the cetane number (cetane improver has no effect on cetane index since it is calculated from properties of the base fuel). Under the Australian standard, diesel containing biodiesel is required to have a DCN of 51 (Table 3.1). The lower the cetane number of the diesel, the more difficult auto-ignition is to achieve. Consequently, cetane number would be expected to have an effect on emissions from an engine. The degree of effect cetane number will have on emissions depends on a number of factors, including:

Fuel system type and its control – mechanical or electrical Combustion system type – direct or indirect injection Low emission control strategies, such as

o Exhaust Gas Recirculation (EGR), o Selective Catalytic Reduction (SCR) or o Diesel Particulate Filter (DPF) o High Pressure and multiple injections per compression stroke

It should also be noted that as cetane number varies so will other fuel properties. Typically, density and poly-aromatic properties will also vary. As such, independently changing the cetane number in a blend is not possible (other than perhaps by cetane enhancers) without affecting other parameters which can also have an impact on performance, emissions and operability.

3.2 Effect of Fuels on Emissions

The effects of cetane number on performance and emissions of older technology diesel engines are reasonably well understood. Older technology engines, in this case those which employ indirect injection or lower injection pressures, rely to a larger extent on the fuel/air mixing in cylinder prior to combustion (premixed combustion). In this situation, the cetane number of the fuel, which affects the ignition delay, has a large effect on the initial combustion. A higher cetane number fuel will have a higher initial pressure rate rise in the cylinder than a lower cetane number fuel. Higher cetane number fuels will generally give rise to lower NOx and noise than lower cetane number fuels. Fuel


consumption is likely to be higher as a result of the lower heating values of higher cetane number fuels. Lower HC and CO emissions have been reported with higher cetane number fuels, whilst the effects on PM appear to be engine specific [6]. More modern diesel engines employ high pressure direct injection technology. One of the aims of this technology is to control the initial combustion of the fuel/air mix through the rate of fuel injection, rather than relying solely on premixed combustion. This has the potential to reduce the effects of the cetane number on engine performance and emissions [6]. The extent of the effect is not well quantified in the literature reviewed. The effects of Biodiesel on heavy duty engine emissions have generally been well documented, even though it is most often compared to high sulphur petroleum diesels in older technology engines as opposed to the low sulphur fuels used in Europe and Australia. The available studies generally show that increasing Biodiesel content is likely to slightly increase NOx, and decrease HC, CO and PM emissions as shown in Figure 3.1 [7]. The change in PM is considered to be strongly associated with the sulphur content of the baseline fuels used, and how these results may apply to a high pressure direct injection engine with low sulphur diesel fuels is being investigated in this study.

Figure 3.1 – Effect of Biodiesel on Heavy Duty Engine Emissions

Fuel density will potentially have an effect on engine emissions. Where all other factors are equal, higher density fuels will lead to a higher fuel mass being injected. This may lead to higher power than a lower density fuel at a similar operating point. The consequence of this is that a higher density fuel would potentially create higher PM and NOx emissions, THC and CO emissions could reduce. These effects however are expected to be more marked on engines with higher emissions levels.


It is expected that higher cetane number fuels will have a lower density than lower cetane number fuels [8]. This combination of cetane number and density effects has the potential to confound the measured emissions. Figure 3.2 shows this graphically. It is to be expected that the effects of cetane number and density potentially complement each other in terms of NOx emissions, and act to negate each other in terms of HC and CO emissions.

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Expected Cetane-Density Correlation

Increasing PM

Increasing NOxIncreasing HC, CO

Increasing Fuel Density

Incr

easi

ng C

etan

e N

umbe

r

Figure 3.2 – Confounding Effect of Fuel Density and Cetane Number on Emissions

The aromatic content of diesel fuel, in particular polyaromatics, can also have an effect on emissions both dependently and independently of the effects that they can have on density and cetane number. Increased total aromatic content may lead to increased NOx emissions, whilst increases in the polyaromatic content may lead to increased HC, NOx and PM emissions. Polyaromatic content, along with total aromatic content, is generally expected to be higher in diesel fuels with a lower cetane rating. This combination of cetane number and aromatic content effects also has the potential to confound the measured emissions. Figure 3.3 shows this graphically. It is to be expected that the effects of cetane number and polyaromatic content potentially complement each other in terms of HC and NOx emissions, but to have independent effects on PM and CO emissions.


0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Expected Cetane-Aromatic Correlation

Increasing PM

Increasing HC, NOx

Increasing CO

Increasing Polycyclic Aromatic Content

Incr

easi

ng C

etan

e N

umbe

r

Figure 3.3 – Confounding Effect of Fuel Density and Aromatic Content on Emissions

Sulphur levels alone are unlikely to affect the gaseous emissions recorded from an engine. It is however expected that higher sulphur levels in a fuel could potentially increase PM by a small amount. Figure 3.4 summarises the effects that potentially could be expected from various fuel properties.

Figure 3.4 – Influence of Fuel properties on Heavy-Duty Diesel Emissions [9]

3.3 Effect of Regulations and Engine Technology on Emissions

Emission standards apply to road transport vehicles sold in Australia. New vehicles (manufactured in volume) are required to be certified to the requirements of the


Australian Design Rules (ADR). The role of the ADRs is to set standards for the minimum level of compliance, essentially defining the requirements to which new vehicles are built to and supplied to the market. The ADRs are typically harmonised to those of a recognised international standard. Used vehicles may be imported under a range of schemes and these too generally require demonstration of emission performances – though the specific requirements may vary.

The ADRs have evolved over the past 30-40 years. Emissions from petrol fuelled vehicles have been regulated since the mid 1970’s, whilst the regulation of diesel vehicles has lagged. Table 3.2 provides a summary of the ADRs applicable to diesel vehicles. This table indicates the date which the specific ADRs came into effect for “all” vehicles manufactured and details some of the specific testing methods. The information is distilled in Figure 3.5. Originally, only smoke was a regulated emission and required control. From 1996 more comprehensive emissions testing became a requirement for diesel vehicles. Emissions controlled included THC, CO, NOx and PM. Under ADR70/00 [3] some light duty vehicles were certified as a vehicle test, whilst others (including medium and heavy duty) were certified on the basis of an engine test. From 2003, all light duty vehicles (under 3.5t GVM, such as passenger and light commercials) have been required to undergo testing as a vehicle over a simulated drive cycle rather than being certified by an engine test. Essentially, diesels in the light duty category are treated comparably to petrol vehicles under ADR79/xx. In the medium to heavy duty categories engine certification remains the required method, although the testing regime has been expanded. The rationale for this division in methodology potentially aligns with the manufacturing practices of the engines. For light duty applications, the engine and vehicle are highly integrated with the same manufacturer supplying both. The onus of compliance rests with the one manufacturer. With heavy duty, and to a lesser extent medium duty, vehicles are sold with option of an engine from one of a number of manufacturers. The onus of compliance for emissions rests with the engine, not the vehicle, manufacturer. A brief summary of the diesel emission ADR requirements is given below:

Vehicle testing ADR79/xx applies to all light duty vehicles from 2003. This includes passenger and light commercials (also medium duty which choose this option). The ADR specifies a transient drive cycle as required for petrol vehicles. The ADR testing is undertaken with a cold start. Vehicle testing also applies to those vehicles certified under the ECE R83 rules in ADR70/00.

Engine testing

ADR70 applied to all vehicle categories (light through heavy duty) although a variety of alternate standards were also accepted. With the introduction of ADR79/xx for light duty, ADR80/xx came into effect for all heavy duty, and all medium duty which do not take up the option for a vehicle test. Both ADR70/00 and ADR80/xx are undertaken with the engine in the hot running state.

Although generally aligned to the European regulations, alternative standards have been, and in some cases continue to be, accepted as recognised alternatives. Figure 3.7 summarises the trends internationally. The European regulations have been trending towards the use of transient test cycles. In the future the indications are for


harmonisation of test cycles and procedures, with the transient cycle conducted both hot and cold, with emission limits set according to jurisdictional requirements [15]. In addition to compliance level, another factor which should be considered is engine technology. For example, with the ADR80/00 compliant category it is possible to have engines which are mechanically or electronically controlled. These engines are likely to perform differently with different fuels. One of the main advancements in diesel engine technology has been the move to more sophisticated injection strategies and higher injection pressures. It is therefore important for the study to capture the technology differences, for example simple vs. complex electronic control. It should be noted that pre-ADR80 the dominant heavy duty engine injection technology was mechanical. The combustion system also is a significant factor. Older engines (predominantly pre-ADR70/00 [5]) were indirect injection, relying on combustion initiating in a pre-chamber and spreading to the main combustion chamber. Newer engines (ADR70/00 onwards) are predominantly direct injection – fuel is injected into the combustion chamber with no pre-chamber featured.


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^1-

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03*

1-Ja

n-07

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08*

1-Ja

n-11

*

Table 3.2 – Summary of Emission ADR History for Diesel Vehicles


ADR70/00EURO-II

ADR30/00 ADR30/01

ADR80/01+EURO-IV

ADR80/00EURO-III

Smoke

Emissions (engine test)

Emissions (vehicle test, light-duty)

1976* 1996* 2003* 2007* 2011*

ADR79/01EURO-IV

ADR79/00EURO-II

* earlier dates for new models

Figure 3.5 – Overview of Emission ADRs for Diesel Vehicles

From: Ullman, Asian Vehicle Emission Control Conference 2004

Figure 3.6 – Overview of Heavy Duty Vehicle European (Euro) Regulation Limits


* EEV = enhanced environment-friendly vehicle

Figure 3.7 – Overview of International Heavy Duty Vehicle (HDV) Emission Testing Trends

The engines used in this study would have been certified to a variety of different tests and exhaust emissions limits based on the engine age, as shown in Table 3.3. In addition ADR80/xx allows alternative procedures for approval, based on European, US EPA CFR and Japanese MLIT Regulations. Each of these regulations stipulate different test cycles and emissions limits. As all engines for this study were manufactured in the USA, it is likely that all would have been certified through the US EPA CFR certification route and approved as ADR80/xx compliant.


Emissions Test Cycle

Effective Dates

New Vehicles All Vehicles

Test Description Alternative Standards

Accepted

1 ADR30

ADR30/00 1/7/1976 1/7/1988

4 mode steady state smoke (opacity) test

ECE R24 US EPS (1974) British Standard (1971)

2 ADR30/01 1/1/2002 1/1/2003

4 mode steady state smoke (opacity) test Free acceleration smoke (opacity) test

UN ECE R24 US CFR 86 (1998, smoke only)

3 ADR70/00 1/7/1995 1/7/1996

R49 steady state 13 mode emissions test

US CFR 86 (1994/1998) European or Japanese Passenger, light, medium and heavy duty regulations (1991/1994)

4 ADR80/00 1/1/2002 1/1/2003

ESC, Euro 3, PM10 ELR ETC*

UN ECE R24 (1999) US CFR 86 (1994/1998)

5 ADR80/02 1/1/2007 1/1/2008

ESC, Euro 4, PM10 ELR ETC

US EPA 2004 Japanese JE05

6 ADR80/03 1/1/2008 1/1/2011

ESC, Euro 5, PM2.5 ELR ETC

US EPA 2007 Japanese JE05

ESC = European Steady Cycle, steady state 13 mode test ETC = European Transient Cycle ELR = European Load Response cycle, “smoke” test * ETC transient emissions test only if fitted with “advanced after-treatment systems”

Table 3.3 – ADR Test Requirements for On-Road Heavy Duty Diesel Engines

3.4 Effect of Engine Load on Emissions

Heavy duty engines are tested according various steady state and transient methods. For certification to the Australian Design Rules, engines designed to ADR80/00 [9] through to 80/03 [13] are tested to the European Steady Cycle (ESC) or equivalent US EPA steady state test [14]. These steady state tests are a series of test points (typically 13) describing various modes of engine operation. The transient test European Transient Cycle (ETC) is also part of the emissions testing regime, with an equivalent US EPA transient cycle also being used to certify engines for use in Australia. Both cycles (steady state and transient) represent a particular engine duty cycle, which in turn represents a particular vehicle, transmission and payload combination. Emissions from a vehicle will vary as a function of various factors, in particular payload (should all other factors remain constant). As payload changes, simplistically the load on the engine will change in order to accelerate the mass or maintain constant speed. In reality, an engine can only ever deliver 100% load, so when this limit is reached either vehicle speed will change (slow down) or a lower gear will be used to multiply the engine torque by a greater factor (and consequently cause the engine speed to increase).


4 EXPERIMENTAL METHOD

4.1 Overview

For each engine, testing was undertaken by Orbital using the heavy-duty engine test facility at Orbital Australia. Testing was conducted using both steady state and transient cycles. For each fuel, testing was repeated at least once (2x tests per fuel). In the case that there was a significant difference in the two results, a third test was conducted. The sequence is shown in Figure 1. In some cases, the baseline fuel (low cetane diesel) was retested to verify that no substantial drift had occurred during the testing sequence. When swapping between fuels, the fuel system was purged and the engine and fuel system conditioned to the new fuel prior to testing. The engine load testing was conducted on each engine using the baseline fuel before swapping to the next engine to be tested. The sequence is also shown in Figure 4.1. The engine load testing first requires the test cycle or points to be determined. This is done by simulation to ultimately provide low and high tare transient and steady state cycles.


Setup engine for testing

2x ESC and ETC tests on fuel #1





Test next Engine?

Yes

Testing completed

No

2x ESC and ETC tests at 97t loading

(fuel #1)

2x ESC and ETC tests at 70t loading

(fuel #1)

Figure 4.1 – Engine Test Sequence

4.2 Engine Selection

According to the project scope, Testing was to be carried out on three heavy-duty engines of 12 litres or greater size.

one ADR80/00 compliant;

one ADR80/02 compliant; and

one ADR80/03 compliant.


Three manufacturers dominate the 12L+ range; Cummins, Caterpillar and Detroit Diesel, with the latter having the smallest market share. From the Cummins and Caterpillar ranges, common on-road engines in the 12L+ ranges are the Cummins ISX and Caterpillar C15 engines. Both of these are of a nominal 15L capacity. Cummins engines were selected for the ADR80/03 (2010MY and later) and ADR80/02 (~2007-2010MY) engines, whereas a Caterpillar C15 was selected for the ADR80/00 (~2002-2007MY) engine. Table 4.1 shows the main specifications of these engines. ADR Level: ADR80/00 ADR80/02 ADR80/03 Emissions Certification

EPA/CARB 2000 EPA/CARB 2004 EPA 2007

Manufacturer Caterpillar Cummins Cummins Model/SPEC C15 98 ISX550 ISX550 Software Ref DM7199 FR10701 FR10782

Injection System Electronic Unit Injection

High Pressure Direct Injection

High Pressure Direct Injection

Emission Controls: Injection Timing/Pressure

Injection Timing/Pressure EGR VGT

Injection Timing/Pressure EGR VGT

Exhaust Aftertreatment

None None Oxidation catalyst Diesel Particulate

Filter (DPF) Serial Number 9NZ15887 79369853 79369853 Capacity 14.6L 14.9L 14.9L Bore/Stroke 137/165mm 137/169mm 137/169mm Rated Power kW@rpm

410@1900 410@2000 410@2000

Rated Torque Nm@rpm

2508@1200 2508@1400 2508@1200

Table 4.1 – Test Engine Specifications

Figure 4.2 shows a typical ADR80/xx engine. Heavy Duty Diesel engines in the 12L+ range utilise a turbo-charger to boost intake air, thereby boosting engine power output. Both the ADR80/00 and ADR80/02 engine tested had a similar overall configuration and utilised no exhaust aftertreatment system. Figure 4.3 shows an example of an ADR80/03 (Euro V or US EPA ’07) exhaust aftertreatment system. The example shown utilises an oxidation catalyst and DPF combination to reduce CO, HC and particulate emissions whilst NOx emissions are controlled inside the combustion chamber of the engine by the use of exhaust gas recirculation (EGR) .


Figure 4.2 – ADR80/xx Heavy Duty Diesel showing Typical Engine Features for this Class of Engine

Figure 4.3 – ADR80/03 level Exhaust Aftertreatment System, as fitted to a Heavy Duty Diesel Engine

Diesel Particulate

Filter Oxidation Catalyst

Engine Exhaust Tailpipe

Exhaust

Intake Air

Engine Exhaust

Turbo-charger Boosted Air to

Intercooler

Boosted Air from Intercooler


4.2.1 On-Road Heavy Duty Truck Fleet

The assessment of load effects on emissions requires selection of a vehicle platform in which drive cycle simulation can be undertaken to arrive at modified test cycles.

Heavy duty diesel engines of greater than 12L capacity are typically fitted to articulated trucks. The articulated truck (AT) vehicle category is unique when compared to the smaller weight categories in that the engines fitted to these vehicles are often sourced from specialist engine suppliers (or independent divisions within OEMs) and are not necessarily designed or developed by the vehicle OEM. For example a Kenworth truck may have been available, at the choice of the purchaser, with either a Caterpillar or Cummins engine. This is true also of other truck manufacturers. It is for this reason that HDV engines (including aftertreatment system), and not the vehicles, require emissions certification. Table 4.2 shows this disconnect between engines and vehicles in the heavy duty category, and provides a point-in-time estimate for which engines are most popular. Nearly 70% of the fleet is fitted with one of the engines from one of the “top 4” ranked manufacturers. In 2008, Caterpillar exited the on-road engine market and it is estimated that Cummins has largely taken up the shortfall with a smaller proportion coming from Detroit Diesel. Even after this re-distribution; the dominance of the new “top 4” is expected to remain. Additionally, technology on these engines is typically aligned with introduction of changes in certification limits or requirements. This means that within a given age category, HDV engines were either equipped with mechanical or electrical injection systems, etc. Data for the 2006 Heavy Duty Vehicle fleet is shown in Figure 4.4 whilst an estimate of engine usage is shown in Figure 4.5. It can be seen that the dominant combination in the Australian fleet will be a Kenworth truck fitted with a Cummins engine.

Scania Hino Isuzu 2009

Ken

wor

th

DA

F

Mer

cede

s B

enz

Fre

ight

liner

Mits

ubis

hi

Wes

tern

Sta

r

Inte

rnat

iona

l

MA

N

Vol

vo

Mac

k

Nis

san/

Nis

san

UD

Sca

nia

Hin

o

Isu

zu

Tot

al

% % (

estim

ated

with

out

Cat

erpi

llar)

Cummins 808 274 237 1319 25.3% 42.4%Caterpillar 808 274 116 1198 23.0% 0.0%Volvo 640 640 12.3% 12.3%Mercedes 120 363 483 9.3% 9.3%Mack 471 471 9.0% 9.0%Detroit Diesel 363 363 7.0% 12.8%Scania 263 263 5.0% 5.0%DAF 118 118 2.3% 2.3%MAN 116 116 2.2% 2.2%Nissan 96 96 1.8% 1.8%Isuzu 88 88 1.7% 1.7%Hino 38 38 0.7% 0.7%Mitsubishi 24 24 0.5% 0.5%

En

gin

e M

an

ufa

ctu

rer

Prime-mover Supplier / Manufacturer Totals2006Paccar MAN VolvoDaimler

Table 4.2 – Estimated Australian HDV Engine Usage (Orbital’s estimate based on marketing information, 2006)


2006 Heavy Duty Vehicle Fleet

Kenworth31%

Freightliner14%

Volvo12%

Western Star10%

Mack9%

International7%

Scania5%

Others12%

Figure 4.4 – Heavy Duty Vehicle Manufacturer Distribution within AT Category

2006 Heavy Duty Engine Fleet

Cummins25%

Caterpillar23%

Volvo12%

Mercedes9%

Mack9%

Detroit Diesel7%

Scania5%

Others10%

Figure 4.5 – Estimated Engine Manufacturer Distribution within AT Category


4.2.2 Selected Vehicle Specifications

The assessment of load effects on emissions requires determination of suitable vehicles. The two vehicle loads to be assessed are 70tonne and 97tonne. Kenworth-DAF WA was approached to provide specifications for trucks which would be configured for these loads. A summary of the specifications they provided are in Table 4.3. More detailed specifications can be found in Appendix 2.

70t GCM 97t GCM

Configuration B-Double Prime Mover, 3 Semi Trailers

and 2 Dollys Prime Mover Model Kenworth T402 Kenworth K108 GCM 70,000Kg 97,000Kg Unladen Mass* 23,708 Kg 37,978 Kg Payload 46,292 Kg 59,022 Kg 50% Laden Mass 46,854 Kg 67,489 Kg Engine Cummins ISX 450 Cummins ISX 525 Max Power 465 hp 550 hp Gears 18 18 Road Conditions Class A (Interstate

Highway/Roads) Class A (Interstate Highway/Roads)

*estimated

Table 4.3 – Kenworth Articulated Truck Specifications

4.3 Test Fuels and Management

The objective of the study was to use commercially available fuels rather than having to resort to the use of cetane enhancers or specialist fuel which may not be representative of fuels found in the Australian market. Table 4.4 outlines the fuels used for this study. As such, the Low Cetane and High Cetane fuels were commercially available fuels acquired with the cetane number at upper and lower values seen during the supply cycle in the period prior to the project’s commencement (September-to-December 2009). Consequently, diesel fuels with marginally higher than the nominated cetane number of 46 and 51 were procured, however the difference between fuels was comparable to the nominated targets. Fuels with high or lower cetane number may be commercially available at other times of the year and/or supply cycle. Both fuels were supplied by BP Kwinana. The B5 and B20 fuels were blended by Orbital from B100 (100% Biodiesel) and the high cetane diesel fuel stock used for testing. The B100 stock was supplied by Biodiesel Producers Limited. Although bio-diesel does increase the cetane number, high cetane diesel fuel (rather than low cetane) was used as the base stock as this ensured that all blended fuels would meet the fuel standard. Samples of the B5 and B20 fuels were analysed by BP after blending by Orbital. The analysis confirmed that the B5 complied with the latest version of the 2001 Diesel Determination [3] for the characteristics tested,


and the B20 also complied, with the exception of Biodiesel content being higher than permitted. The R50 was the only non-commercially available research fuel supplied for evaluation in this study. R50 is a synthetic diesel with a 50% renewable component. R50 was included in the test matrix as it represents a low density diesel which, though presently non-compliant with the fuel density limits of the national standard, has the potential to offer CO2 reductions. Analysis of all fuels is available in Appendix 1.

Fuel Base Stock

Cetane Index

(calculated)

Derived Cetane Number

(measured)

Densityg/L @ 15°C

Renewable Content

Total Aromati

c Content

Poly aromati

c content

Gross Specifi

c Energy MJ/kg

Low Cetan

e - 48 47.6 848.5 None 30.8 6.4 43.8

High Cetan

e - 53 52.3 837.5 None 23.1 4.0 46.5

B5 High

Cetane

53 54.5 839.4 5%

Biodiesel 23.9 8.8 46.3

B20 High

Cetane

53 56.1 844.6 20%

Biodiesel 24.1 5.9 45.6

R50 - 74 >61 806.3 50%

Renewable Diesel

15.4 6.2 47.6

Table 4.4 – Project Fuels Properties

These fuels were separately stored to avoid any mixing with other test fuels, and to protect the batches from contamination. The low cetane fuel was stored in a flushed bulk tank, and decanted into clean 200L drums for use. The other fuels were stored in sealed 200L drums. Each fuel drum was checked for contamination before use by visually inspection of a sample taken from the bottom of the undisturbed drum.


4.4 Heavy Duty Engine Testing

4.4.1 Test Cycles Used

In order to accurately measure how fuel composition and engine load may effect the emissions across the various engines tested, all engines must be subjected to the same test regime, regardless of their original certification requirements.

ADR80/03 was the test method selected for assessing the effects of fuel composition on engine emissions, whilst the specific test cycles prepared for assessing engine load effects were similarly based on ADR80/03 testing, sampling and calculation methods.

ADR80/03 specifies three test cycles for examining heavy duty truck engine exhaust emissions. They are the European Stationary Cycle (ESC), the European Load Response (ELR) and the European Transient Cycle (ETC) tests. Only the ESC and ETC were used.

The ESC (Figure 4.6) is a steady state 13 mode test where the load, speed and weighting of each point have been specified to represent on-road emissions levels. This ESC for Euro 3 onwards is different to the earlier 13 mode cycle specified for Euro 1-2. Results for the ESC have units of g/kWh. Prior to the ESC a power curve test is undertaken to establish rated power and speeds. This information is used to determine the specific points to be operated at during the ESC. For the comparative testing undertake in this study, the three random sampling points are omitted.

The ETC (Figure 4.7) is a transient test representing a real heavy duty truck drive cycle. Results for the ETC have units of g/kWh. Note: the ESC test predates the ETC test; results from these two tests are not expected to be equivalent.


Idle

A

% % %

% % %

% % %

% % %

%

En

gin

e L

oa

d [

%]

0

25

50

75

100

Speed [%]

0 25 50 75 100

15

5 10 5

5 10 5

5 10 5

8 9 8

B C

1

7 9 11

5 3 13

6 4 12

2 8 10

Mode Engine SpeedEngine Load

Weighting Factor Duration

1 Idle 0 15% 4 minutes 2 A 100% 8% 2 minutes 3 B 50% 10% 2 minutes 4 B 75% 10% 2 minutes 5 A 50% 5% 2 minutes 6 A 75% 5% 2 minutes 7 A 25% 5% 2 minutes 8 B 100% 9% 2 minutes 9 B 25% 10% 2 minutes

10 C 100% 8% 2 minutes 11 C 25% 5% 2 minutes 12 C 75% 5% 2 minutes 13 C 50% 5% 2 minutes

Figure 4.6 – ESC Engine Test Cycle (Euro 3, 4, 5)


Figure 4.7 – ETC Engine Test Cycle

4.4.2 Engine Dynamometer(s) Steady state engine testing can be accomplished using a conventional brake dynamometer. For steady state testing the engine speed is controlled by the dynamometer absorbing the torque (load) the engine outputs. Transient testing requires the dynamometer configuration to modulate the load absorbed thereby allowing the engine to accelerate or decelerate, thereby simulating its operation as fitted to a vehicle. The test facility used for this study employs an AC dynamometer and water brake dynamometer in series to accomplish the transient simulation requirement. The combination is capable of continuous operation at 484kW (650hp). This combination, as shown in Figure 4.8 and Figure 4.9, is capable of 480Nm of motoring torque and 4480Nm of brake torque. Fast transient response allows real time emissions measurement of simulated vehicle drive cycles such as the ETC and Diesel CUEDC. The facility is suitable for heavy duty engine certification to US, European and Harmonised Standards. This engine test facility was supported by a grant from the Australian Federal Government with the objective of improving testing accuracy for medium and heavy duty applications to the level required for compliance or certification, complementing light duty facilities with the same capability.


Figure 4.8 – Heavy Duty Engine Facility

Figure 4.9 – Heavy Duty Engine Dynamometer Layout

Engine Coupling

Test Engine Water Brake

Dyno

AC Dyno

Intake

Fuel Flow Meter

Exhaust Flow Meter

Intake Air Intercooler

Exhaust

PM Micro-tunnel


4.4.3 Emissions Sampling Emissions measured were CO, CH4, HC, NOx, CO2 and PM (PM as PM2.5). Fuel consumption was determined by carbon balance.

Gaseous emissions concentrations are sampled directly from the undiluted (“raw”) exhaust stream. Gaseous emissions are measured by a Horiba gas analysis bench as concentrations and using exhaust flow measured by the Pitot Tube Flow Meter (PTFM) a mass emission rate can be calculated.

For a steady state cycles such as the ESC, gaseous emissions are measured at each test point and the individual results combined after being appropriately scaled by the required weighting factor. The sample is taken once engine operation has stabilised at the test point. For transient cycles such as the ETC, gaseous emissions are measured on a second-by-second basis and integrated to obtain the total test result.

Particulate emissions are sampled using a Horiba MDLT-1300T series partial flow dilution tunnel. The general layout of this is shown in Figure 4.10, where it is compared to a full-flow dilution system. PM is sampled by diluting part of the overall engine exhaust flow. Total exhaust flow rate is measured, and the volume of the exhaust flow transferred to the micro dilution tunnel system is kept proportional to total exhaust flow. The particulate sampling system is within a temperature regulated enclosure to reduce the effects of any volatile compounds being collected on the sample filters.

The particulate matter is deposited on 47mm or 70mm filters, which are weighed before and after the test to determine the mass of particulate matter deposited. A cyclone pre-classifier is used upstream of the filter. Only a single (primary) filter is used (as per ADR80/03). The use of a cyclone filter means only PM2.5 is gravimetrically measured. Filter conditioning and mass measurement is conducted in a temperature and humidity controlled facility. The microbalance used is a Thermo Cahn Microbalance model C34 which has an accuracy of 5.0µg and a readability of 1.0µg. The filter particulate mass is then scaled for the dilution and sampling ratio used to calculate the total cycle particulate mass.

For a steady state cycle such as the ESC, PM emissions for all test points are sampled on to a single filter by flowing the diluted exhaust sample through the filter at each test point for its required sample time. This sample time is proportionate to the required weighting factor for each test point, thereby the one filter has a PM sample representative of the whole weighted cycle. For transient cycles such as the ETC, PM emissions are sampled on to the one filter by flowing the diluted exhaust sample for the complete cycle duration.


Figure 4.10 – Partial Flow (Micro) compared to a Full Dilution Tunnel [16]

4.5 Development of Alternate Loading Engine Test Cycles

4.5.1 Origin of the European Transient Cycle (ETC) The ETC engine test cycle has been developed from a previous vehicle based transient cycle, known as the FIGE transient cycle, or the FIGE cycle, developed by the Forschungsinstitut für Geräusche und Erschütterungen (FIGE).

The FIGE cycle is a real world test cycle developed as a practical alternative to the 13 mode cycle. The data for the test cycle was drawn from a study carried out on 17 different goods vehicles from small delivery vans to 40 tonne articulated vehicles and 3 local public transport buses. The tests were carried out in Germany and as part of the testing 5 representative vehicles from the former East Germany were also tested [17].

From the study a transient driven test cycle was developed in order to allow emission levels to be determined under dynamic operating conditions. The cycle consists of three distinct operating phases:

(1) An urban cycle lasting 600 seconds with speeds up to 50km/h.

(2) A rural cycle lasting 600 seconds with speeds up to 80km/h.

(3) A motorway cycle lasting 600 seconds with speeds up to 90km/h

This vehicle based test cycle is referred to as the FIGE drive cycle and is shown in Figure 4.11. Table 4.5 shows an analysis of the FIGE drive cycle. Data for the FIGE cycle was taken from a 2003 report [17].


Figure 4.11 – FIGE Vehicle Test Cycle (resultant ETC is shown in Figure 4.7)

Road Flow Category

Total Dist (km) Total Time (secs) Average Speed

(km/h) Urban 3.874 600 23.25 Rural 11.557 600 69.34 Motorway 14.063 600 84.38

Totals 29.494 1800 58.99

Table 4.5 – Selected Parameters for the FIGE Cycle

4.5.2 Vehicle Road Load Estimation It was agreed with stakeholders that both trucks would be simulated at 50% laden mass, as assumed for most heavy duty emissions inventory work. The road load factors for these configurations were estimated from the road load curves obtained from the VVT Technical Research Centre of Finland [18]. As is typically done for drive cycle modelling, the assumption made is that the road gradient is zero. Figure 4.12 shows the original curves and the estimates made.


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97t 50% laden estimate 60t truck with full trailer70t 50% laden estimate 42t semi-trailer26t Truck 18t truck

Figure 4.12 – Road Load Estimations

4.5.3 Drive Cycle Simulation Results By combining inputs such as the drive cycle, shifting schedule, vehicle road loads, inertias and suitable estimates for transmission and other losses, the amount of power required by the engine to complete the vehicle drive cycle was calculated using Orbital’s in-house vehicle simulation software. Figure 4.13 and Figure 4.14 show the results of this simulation for 70 and 97 tonne vehicle combinations, respectively. The simulations have assumed the end of the urban phase to be at 585 seconds (idle period), and the start of the motorway phase at 1184 seconds. It can be seen that although the motorway phase has the highest vehicle speeds, whilst the highest power requirements are during the Rural phase which has higher acceleration rates.


70t Phase 1 Engine Cycle

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Figure 4.13 – 70t Vehicle Drive Cycles as Simulated



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Figure 4.14 – 97t Vehicle Drive Cycles as Simulated


4.5.3.1 Transient Test Engine Cycles Due to the similarity in engine power ratings, drive cycles were simulated only for one engine specification. As per the ADR80/03 methodology, the engine cycle for each phase was then normalised into % speed and % load. These normalised cycles, as shown in Figure 4.15 and Figure 4.16, were used for all three engines. Testing was undertaken separately for each of the three phases and the results combined to obtain a total cycle result. Gathering of the data as individual phases enhances its usability for inventory modelling.

Drive Cycle Velocity (km/h)

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Figure 4.15 – 70t Transient Engine Test Combined Cycle


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Figure 4.16 – 97t Transient Engine Test Combined Cycle

4.5.3.2 Steady State (Modal) Cycles Steady state cycles were generated to represent the high and low load cases for the combined FIGE drive cycle (containing all three phases). These were based on the ESC test cycle, but with each of the test points weighted differentially to better represent the vehicle loading case. Table 4.6 displays the resulting test cycles. The standard ESC is included only for reference, as it was not based on the ETC or FIGE cycles. It was found that for the 70t cycle two modes had weightings (i.e. sample times) so low as to make accurate particulate sampling impractical. These modes were removed from the sampling schedule, as their impact on the total test result was demonstrated to be insignificant. The weighting of each mode point represents not only the time spent at


that point, but the contribution from time spent on the simulated transient cycle at nearby points. To explain, both 70 and 97t cycles have similar times at idle, however the 70t vehicle spends more time at low loads near idle and as such has the idle point is weighted higher to account for this.

Weighting Mode

Engine Speed

Engine Load ESC 70t 97t

1 Idle 0 15% 34.9% 26.9% 2 A 100% 8% 2.5% 2.5% 3 B 50% 10% 10.0% 15.9% 4 B 75% 10% 1.4% 6.5% 5 A 50% 5% 8.1% 7.5% 6 A 75% 5% 4.6% 4.8% 7 A 25% 5% 13.4% 9.0% 8 B 100% 9% 0.3% 4.6% 9 B 25% 10% 23.4% 14.8%

10 C 100% 8% 0.1% 2.8% 11 C 25% 5% 1.4% 1.4% 12 C 75% 5% Omitted 1.9% 13 C 50% 5% Omitted 1.3%

Table 4.6 – 70t and 97t Steady State Tests


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Figure 4.17 – Low and High Load Steady State Tests


5 FUEL COMPOSITION TEST RESULTS

5.1 Presentation and Interpretation of Results

Engine exhaust emission results are presented as g/kWh or g/hr, as appropriate, after being converted from their original sample collection units which may have been either concentration or mass. Results expressed as g/hr are emission rate results (grams of pollutant per hour of operation). Results expressed as g/kWh are referred to as “brake specific” results since the emission rate is normalised against the average power output at the point the result was taken. Normalisation of the result to g/kWh units allows different power output engines and technologies to be compared.

The results discussed in the following sections represent the average of replicate tests, and in most cases only the total (overall) cycle result is presented. Phase-by-phase and modal data is available as part of the dataset but has not been detailed in this report. As per ADR80/03 regulations, results have not been corrected for background or ambient levels.

Error bars on the graphs represent the variation between lowest and highest result recorded. Showing the spread in the recorded results is helpful in understanding the experimental variation observed and provides an indication of whether the effects of individual loads or fuels are discernable from this variation. Where results from different pollutants are shown on the same graph the labels on the horizontal axis will indicate the scaling factor used to plot the results. Whilst methane emissions were recorded for all tests, the total methane emissions were negligible for all engines on both ESC and ETC tests. As such, methane emissions will not be discussed in any detail. It is generally considered that diesel engines produce insignificant quantities of methane. It would however be expected that methane emissions would be far more significant on a heavy duty engine fuelled with CNG or LNG, whether single or dual fuelled.

5.2 ADR80/00 Engine Results

Figure 5.1 and Figure 5.2 show the brake specific exhaust emissions results from the ADR80/00 engine for each of the five fuels tested over the ESC and ETC tests, respectively. Steady State (ESC) and transient (ETC) tests show some similar trends. Compared to the baseline low cetane diesel:

• NOx emissions are 6-8% lower with R50 fuel. • PM emissions are 17-27% lower with B20 fuel and potentially lower for R50.

Whilst ESC testing this engine occasionally very high PM emissions were produced, with no change to other pollutants. The Low and High Cetane data below show this in the variation (error bars), but there is no reason to believe that this behaviour is linked to only these fuel types.

• CO emissions are approximately 6% lower with B20 fuel. On the transient test only, CO emissions are also lower for the high cetane and R50 fuels.

• HC or NMHC emissions are 13-21% lower for the R50 fuel, and 4-15% lower for the B20 fuel.


• CO2 and FC are approximately 1% lower with high cetane fuel and approximately 2% lower with R50 fuel.

ADR80/00 Engine - Fuel Effects On ESCEuropean Steady State Cycle

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Figure 5.1 – ADR80/00 ESC Results

ADR80/00 Engine - Fuel Effects On ETCEuropean Transient Cycle

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Figure 5.2 – ADR80/00 ETC Results


Figure 5.3 shows the average full-load torque delivered by the ADR80/00 engine for each of the five fuels tested. It can be seen that with this engine, the R50 and B20 fuels gave lower torque than the other fuels. The largest difference is R50, with a peak torque approximately 1.5% lower than the high and low cetane fuels.

ADR80/00 Engine Measured Torque

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Figure 5.3 – ADR80/00 Full-Load Torque Curves

5.3 ADR80/02 Engine Results

Figure 5.4 and Figure 5.5 show the brake specific exhaust emissions results from the ADR80/02 engine for each of the five fuels tested over the ESC and ETC tests, respectively. Steady State (ESC) and transient (ETC) tests show some similar trends. Compared to the baseline low cetane diesel:

• NOx emissions are lower for the B5 and B20 biofuels over the ESC, but higher over the ETC.

• PM emissions are 20-30% lower for B20, and possibly also lower for the high cetane diesel and R50 fuels

• CO emissions are 10-15% lower for B20, but approximately 15% higher for R50 and possibly also higher for B5

• HC or NMHC emissions are lower for the R50 fuel, with variable results for the other fuels – potentially because of the comparatively low absolute value of the results being measured.

• CO2 and FC are approximately 3% lower for the R50 fuel, with negligible differences between the other fuels. This appears to correspond to R50 having a density 4-5% lower than the other fuels.


Comparing only low and high cetane diesels, it is possible that a marginal NOx / PM trade-off is seen over the ESC with NOx increasing slightly for a small reduction in PM. The significance of this trend is marginal because of the testing variation observed. No such NOx / PM trend is seen over the ETC.


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Figure 5.6 shows the average full-load torque delivered by the ADR80/02 engine for each of the five fuels tested. It can be seen that with this engine, the B20 fuel gave lower torque, and the R50 fuel gave higher torque than the base low cetane fuel. There is also some indication that the engine torque is also reduced with B5 fuel.

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5.4 ADR80/03 Engine

Figure 5.7 and Figure 5.8 show the brake specific exhaust emissions results from the ADR80/03 engine for each of the five fuels tested over the ESC and ETC tests, respectively. The ADR80/03 ISX engine exhaust aftertreatment includes an oxidising catalyst and a DPF. These aftertreatment devices can be very efficient at reducing THC, CO and PM emissions. A diesel engine can be calibrated to reduce NOx emissions at the expense of increased THC, CO and PM emissions through optimising fuel injection and use of EGR. In order to meet the low legislated NOx target, it would appear that the engine has been optimised for very low NOx emissions, with THC, CO and PM emissions reduced by the exhaust aftertreatment. Steady State (ESC) and transient (ETC) tests show some similar trends. Compared to the baseline low cetane diesel:

• NOx emissions similar for all fuels, with the possible exception of high cetane over the ESC cycle.

• PM emissions are potentially lower for high cetane, B5 and B20 when measured at steady state. However, this trend is not seen during transient testing. R50 values are similar to low cetane. The variability with B5 is potentially a consequence of one of the replicates having been performed after the DPF had regenerated and was thus operating more efficiently.

• CO emissions are potentially lower for all fuels, which is particularly clear when measured at steady state. However, the significance of this is marginal for high


cetane diesel. It should be noted that all CO results for this engine are of comparatively low absolute value as a consequence of the exhaust aftertreatment fitted.

• HC or NMHC emissions are potentially lower for the biofuels and R50 fuel, which is particularly clear when measured at steady state. It should be noted that all HC results for this engine are of comparatively low absolute value as a consequence of the exhaust aftertreatment fitted.

• CO2 and FC are approximately 3% lower for the R50 fuel, with negligible differences between the other fuels. This appears to correspond to R50 having a density 4-5% lower than the other fuels.

Because of the effectiveness of the exhaust aftertreatment system in treating HC/CO/PM emissions, it is difficult to be conclusive about any observed NOx / PM trade-off. Comparing only low and high cetane diesels, it is possible that a marginal NOx / PM trade-off is seen over the ESC with NOx increasing slightly for a small reduction in PM. The trade-off is also seen over the ETC. The significance of this trend is marginal because of the testing variation observed.


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Figure 5.9 shows the average full-load torque delivered by the ADR80/03 engine for each of the five fuels tested. As can be seen, there are only small differences. For most fuels the average torque measured is within the expected range of test-to-test variability. Only B20 shows a 1-3% lower torque than the other fuels.


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5.5 Summary of Fuel Composition Results

The emission results for each of the three engines have been individually presented previously. To assess if the observed trends are consistent across all three engines included in this study, key emissions data for NOx, PM and CO2 is repeated below focusing on specific fuel composition questions.

5.5.1 Comparison of Low and High Cetane Diesel The results for the low and high cetane fuels are examined for all three engines. Figure 5.10 compares NOx emissions. None of the engines demonstrated a consistent change in NOx emissions with the use of high cetane diesel. Although there was some overlap of results, all engines showed higher average NOx emissions with high cetane fuel during steady state testing, and lower average NOx emissions during transient testing. This indicates that any effect of these fuels on NOx emissions will be highly dependant on the vehicle drive cycle. The high cetane fuel’s lower density and higher cetane rating could be expected to produce lower NOx emissions in older technology engines with higher emissions. If an effect of the polyaromatic content of the fuels was measurable, it would be expected to have a similar effect. Figure 5.11 compares PM emissions. The ADR80/02 engine did show a potentially significant reduction in PM emissions with the use of high cetane fuel. This may be an effect of the lower density and expected lower polyaromatic content of the high cetane fuel, as both of these parameters in isolation would be expected to reduce PM emissions. However, this reduction was not consistently demonstrated by the other engines; potentially because of variability in PM emissions produced by the ADR 80/00


engine and the use of a DPF on the ADR80/03 engine results in very low absolute levels of PM emissions. Figure 5.12 compares CO2 emissions. Most results indicate a change towards lower CO2 with the increase in cetane. The average differences for all engines were within 1.5%, so potentially not significant.

ESC: NOx Trends with Fuels

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Figure 5.12 – CO2 Results: Low vs High Cetane

5.5.2 Comparison of Biodiesel Results The results for both biofuels are compared to the high cetane fuel (identified as B0) used as the base fuel for the biofuel blends. Figure 5.13 compares NOx emissions. The trends are contradictory for ESC and ETC tests, but appear consistent across all three engines. All engines show increases in NOx emissions for the ETC (transient) test. Both ADR80/02 and ADR80/03 engines showed reductions in NOx emissions with the biodiesel blends for ESC (steady state)


tests. Any potential reduction in the ADR80/00 engine NOx emissions for the ESC test was masked by the larger variability in the B0 NOx emissions. Figure 5.14 compares PM emissions. The ADR80/00 and ADR80/02 engines show a consistent reduction in PM for the B20 blend. Results for the B5 blend are not consistent. The use of a DPF on the ADR80/03 engine results in very low absolute levels of PM emissions with no measureable differences between the fuels. Figure 5.15 compares CO2 emissions. The engines as tested did not demonstrate a consistent change in CO2 emissions with biodiesel content.


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Figure 5.13 – NOx Results: Biodiesel vs Diesel



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PM

2.5

(g/k

Wh

)

B0 B5

B20

Figure 5.14 – PM Results: Biodiesel vs Diesel




400

450

500

550

600

650

700

ADR80/00 ADR80/02 ADR80/03


CO

2 (g

/kW

h)

B0 B5

B20


400

450

500

550

600

650

700

750

ADR80/00 ADR80/02 ADR80/03


CO

2 (g

/kW

h)

B0 B5

B20

Figure 5.15 – CO2 Results: Biodiesel vs Diesel


5.5.3 Low Density Fuel Results The results for low density synthetic diesel (R50) are compared directly to both the low and high cetane diesel that were commercially available and comply with the Australian fuel standard [3]. The synthetic diesel (R50) fuel has a density lower than that accepted by the Australian national fuel standard for automotive diesel fuels. Figure 5.16 compares NOx emissions. The ADR 80/00 engine showed a 6-8% reduction in NOx emissions with the low density fuel. No consistent trend with the other engines was identified, with NOx emissions within the spread of low and high cetane diesel. Figure 5.17 compares PM emissions. The low density synthetic diesel would appear to indicate lower PM emissions. This is clearly seen with the ADR80/00 engine but the effects are reduced for the newer specification engines, where the results are increasingly within the spread of the low and high cetane fuels. The effect on PM is likely to be more related to the change in density, than the fact that the R50 has a higher cetane number (see section 3.2). The use of a DPF on the ADR80/03 engine results in very low absolute levels of PM emissions with no measureable differences between the fuels. Figure 5.18 compares CO2 emissions. The low density renewable fuel consistently shows 2-3% lower CO2 emissions than the low and high cetane fuels. The low density renewable fuel also consistently shows 2-3% lower gravimetric fuel consumption. Given the R50 fuels lower density, however, the same gains will not be seen in volumetric fuel consumption. The R50 fuel is 4-5% lower density than the baseline fuels, so would be expected to show a slight increase in volumetric fuel consumption when compared to the low cetane and high cetane fuels.



0

1

2

3

4

5

6

7

8

ADR80/00 ADR80/02 ADR80/03


NO

x (g

/kW

h)

Low Cetane

HighCetane

R50


0

1

2

3

4

5

6

ADR80/00 ADR80/02 ADR80/03


NO

x (g

/kW

h)

LowCetane

HighCetane

R50

Figure 5.16 – NOx Results: Low Density vs Regular Diesel



0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

ADR80/00 ADR80/02 ADR80/03


PM

2.5

(g/k

Wh

)LowCetane

HighCetane

R50


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

ADR80/00 ADR80/02 ADR80/03


PM

2.5

(g/k

Wh

)

LowCetane

HighCetane

R50

Figure 5.17 – PM Results: Low Density vs Regular Diesel




400

450

500

550

600

650

700

ADR80/00 ADR80/02 ADR80/03


CO

2 (g

/kW

h)

LowCetane

HighCetane

R50


400

450

500

550

600

650

700

750

ADR80/00 ADR80/02 ADR80/03


CO

2 (g

/kW

h)

LowCetane

HighCetane

R50

Figure 5.18 – CO2 Results: Low Density vs Regular Diesel


5.6 Discussion: Fuel Composition Effects on Heavy Duty Engine Emissions

It has been noted that although many fuel effects are seen to be common to both the ESC and ETC cycles, NOx emissions, have repeatedly displayed opposing trends on the two cycles. This may be due to the different combustion conditions under steady state and transient conditions.

During the ESC test the engine stays at a constant speed and load for typically one minute before and one minute during emissions sampling. This allows time for turbo speed, EGR flows, combustion chamber temperatures and any other engine variables to stabilise. During the ETC test the engine spends a lot more time transitioning between different loads and speeds, whilst emissions sampling is continuous. This means transient effects are also being measured.

For example, with an increasing torque or speed demand a diesel engine’s increase in turbo speed and combustion chamber temperatures will typically lag behind the increase in fuel injection quantity. This can often lead to a period of lower temperatures and air to fuel ratio than would be experienced during steady state testing at similar speeds and loads. This could lead to higher PM emissions during accelerations. Engine EMS systems often take actions such as reducing or stopping EGR flow during accelerations, which would have the effect of reducing PM, but potentially increasing NOx emissions.

During decreasing torque or speed demands or changes in engine speed similar transient effects on combustion would be seen which would not be represented in a steady state test cycle.

The ADR80/00 engine is the only engine tested here not equipped with an EGR system and a variable geometry turbo (VGT). Although this engine uses electronic control of fuelling, its ability to optimise NOx and PM is limited compared to the more modern engines and this may effect how this engine has been calibrated for steady state versus transient conditions.

Comparison of Low and High Cetane Diesel

The effects of the high and low cetane fuels on NOx emissions were minimal for all engines. Although the differences were small, all engines showed a slight increase in average NOx emissions during steady state testing and a slight decrease during transient testing. This indicates that any effect is potentially highly dependant on the vehicle drive cycles over which they were measured.

Only the ADR80/02 engine consistently showed across both the steady state and transient cycles the expected trend of higher cetane reducing PM emissions. This may be an effect of the lower density and expected lower polyaromatic content of the high cetane fuel, as both of these parameters in isolation would be expected to reduce PM emissions (see section 3.2). The ADR80/00 engine demonstrated this during transient testing, but higher variation in results may have masked the effect during steady state testing. The exhaust aftertreatment on the ADR80/03 engine prevented any difference being measureable due to the very low absolute level of emissions.

The average CO2 differences for all engines with the high and low cetane fuels were small, with the CO2 reduction for high cetane potentially up to 1.5%. The fuel consumption (BSFC) trend follows the CO2 trend. This is contrary to what may have been expected (section 3.2) as high cetane diesel typically has a lower heating value.


Despite the lower density for high cetane, analysis of the fuel used in this study showed it to have higher heating value both on a gravimetric and volumetric basis,

Comparison of Biodiesel Results

All three engines reflected the expected trend for a slight increase in NOx emissions during the transient tests, but the ADR80/02 and ADR80/03 engines displayed an opposite trend for the steady state tests, where biodiesel seemed to reduce the NOx emissions. The trends were more consistent for B20, with B5 results not always seen to lie between B0 and B20.

PM emissions for the ADR80/00 and ADR80/02 engines were seen to fall with the use of B20 fuel. The trends were more consistent for B20, with B5 results not always seen to lie between B0 and B20. The exhaust aftertreatment on the ADR80/03 engine prevented any difference being measureable due to the very low absolute level of emissions.

The engines as tested did not demonstrate a consistent change in CO2 emissions with biodiesel content

Low Density Fuel Results

The results for low density synthetic diesel (R50) are compared directly to both the low and high cetane diesel that were commercially available and comply with the Australian fuel standard [3]. The synthetic diesel (R50) fuel has a density lower than that accepted by the Australian national fuel standard for automotive diesel fuels. The R50 fuel had polyaromatic content similar to the low cetane fuels, and a cetane rating significantly above the high cetane fuel.

The ADR 80/00 engine showed a 6-8% reduction in NOx emissions as could be expected with the lower density and higher cetane of the R50 fuel, but no consistent trend was identified with the other engines.

The expected trend of lower PM2.5 emissions with the low density fuel was clearly seen with the ADR80/00 engine but the effects were reduced for the more modern engines, where the results are increasingly within the spread of the low and high cetane fuels. The exhaust aftertreatment on the ADR80/03 engine prevented any difference being measureable due to the very low absolute level of emissions.

The low density fuel consistently shows 2-3% lower CO2 emissions and gravimetric fuel consumption. Given the R50 fuels lower density, however, the same gains will not be seen in volumetric fuel consumption. The R50 fuel is 4-5% lower density than the baseline fuels, so would be expected to show a slight increase in volumetric fuel consumption when compared to the low cetane and high cetane fuels.


6 LOAD EFFECTS: TEST RESULTS

6.1 Presentation and Interpretation of Results

The format of results follows that outlined in section 5.1 for the fuels testing. As the data from this part of the study is more likely to be directly used in inventory modelling, the results are presented as emissions rates (grams/hour), as opposed to brake specific values (g/kWh).

Only total cycle results are presented and discussed. Results for the steady testing include mode-by-mode gaseous results and for the transient cycle phase-by-phase gaseous and PM results.

6.2 ADR80/00 Engine

Figure 6.1 shows the steady state cycle results for 70t and 97t configurations. Figure 6.2 shows the relative change in emissions between the two configurations. Figure 6.3 and Figure 6.4, respectively, show the same comparisons but for the transient cycle.

Steady State and transient tests generally show similar trends. Compared to the low load case, increasing payload will have the following effects on emissions:

• NOx emissions are increased 42% for the steady state cycle and 26% for the transient cycle.

• PM emissions (perhaps surprisingly) on average showed no change in response to the increase in payload. There is however significant variability in the repeatability of results.

• CO emissions are increased 9% for the steady state cycle but decreased 14% for the transient cycle. Whilst the changes are repeatable, the absolute emission levels are comparatively small with respect to the other pollutants.

• HC or NMHC emissions are increased 33% for the steady state cycle and 17% for the transient cycle.

• CO2 and FC are increased 53% for the steady state cycle and 39% for the transient cycle, as would be expected and is comparable to the change in cycle average power or work.


ADR80/00 Engine - Load Effects OnSteady State Cycles

0

1

2

3

4

5

6

7

8

9

10

Power kW * 0.01 CO kg/h * 100 HC g/h * 0.1 NOx kg/h * 1 PM g/h * 1 CO2 kg/h * 0.1 FC kg/h * 0.1

70t97t

Figure 6.1 – Load Effects: ADR80/00 Steady State Cycle Results

ADR80/00 Engine % Change due to increasing load from 70t to 97temissions rates in terms of g/h

-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

EstimatedPayload

Power CO HC NOx PM CO2 FC

Figure 6.2 – Load Effects: ADR80/00 Change in Steady State Cycle Emissions


ADR80/00 Engine - Load Effects OnTransient Cycles

0

1

2

3

4

5

6

7

8

9

10

Work kWh * 0.1 CO kg/h * 10 NMHC g/h * 0.1 NOx kg/h * 1 PM g/h * 0.1 CO2 kg/h * 0.01 FC kg/h * 0.1

70t 90t

Figure 6.3 – Load Effects: ADR80/00 Transient Cycle Results


-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

EstimatedPayload

Work CO NMHC NOx PM CO2 FC

Figure 6.4 – Load Effects: ADR80/00 Change in Transient Cycle Emissions


6.3 ADR80/02 Engine


Steady State and transient tests show similar trends. Compared to the low load case, increasing GCM will have the following effects on emissions:

• NOx emissions are increased 47% for the steady state cycle and 19% for the transient cycle

• PM emissions are increased 114% for the steady state cycle and 105% for the transient cycle

• CO emissions are increased 73% for the steady state cycle and 80% for the transient cycle

• HC or NMHC emissions on average increase by 9% for the steady state cycle and 22% for the transient cycle. However, test-to-test variability is significant.

• CO2 and FC are increased 48% for the steady state cycle and 44% for the transient cycle, as would be expected and is comparable to the change in cycle average power or work.


0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Power kW * 0.01 CO kg/h * 10 HC g/h * 0.1 NOx kg/h * 10 PM g/h * 0.1 CO2 kg/h * 0.01 FC kg/h * 0.1

70t97t



ADR80/02 Engine - % Change due to increasing load from 70t to 97temissions rates in terms of g/h

-100%

-50%

0%

50%

100%

150%

EstimatedPayload




0

1

2

3

4

5

6

7

8

9

10

Work kWh * 0.1 CO kg/h * 10 NMHC g/h * 0.1 NOx kg/h * 10 PM g/h * 0.1 CO2 kg/h * 0.01 FC kg/h * 0.1

70t 97t




-100%

-50%

0%

50%

100%

150%

EstimatedPayload



6.4 ADR80/03 Engine


Steady State and transient tests show some similar trends. Compared to the low load case, increasing GCM will have the following effects on emissions:

• NOx emissions are increased 56% for the steady state cycle and 11% for the transient cycle.

• PM emissions are increased 45% for the steady state cycle and 28% for the transient cycle.

• CO emissions are reduced 6% for the steady state cycle and increased 43% for the transient cycle.

• HC or NMHC emissions are reduced 62% for the steady state cycle and increased 70% for the transient cycle. However, closer examination of the data would suggest that the test-to-test variability is significant for both cycles.

It is suggested that the increased exhaust and aftertreatment temperatures seen when the engine is operating at steady state at higher loads potentially increases the oxidation rate of CO and HC (including NMHC) pollutants. When operating transiently, the exhaust and aftertreatment does not reach the same heat soaked conditions. Alternatively, or in addition to this, it may be that any improvement in oxidation of HC and CO would be offset by increased production of them during the more frequent maximum load accelerations and gear changes.


CO2 and FC are increased 48% for the steady state cycle and 44% for the transient cycle, as would be expected and is comparable to the change in cycle average power or work.


0

1

2

3

4

5

6

7

8

9

10

Power kW * 0.01 CO kg/h * 100 HC g/h * 1 NOx kg/h * 10 PM g/h * 10 CO2 kg/h * 0.01 FC kg/h * 0.1

70t97t



-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

EstimatedPayload





0

1

2

3

4

5

6

7

8

9

10

Work kWh * 0.01 CO kg/h * 100 NMHC g/h * 1 NOx kg/h * 10 PM g/h * 10 CO2 kg/h * 0.01 FC kg/h * 0.1

70t 97t



-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

EstimatedPayload




6.5 Summary of Load Effect Results

The effects of load on emissions for each of the three engines have been individually presented previously. To assess if the observed trends are consistent across all three engines included in this study, key emissions data for NOx, PM and CO2 is repeated below.

Figure 6.13 compares the emissions over the steady state cycle and Figure 6.14 those on the combined (urban, rural and motorway) transient cycle. These figures compare the relative change in emissions in going from 70t to 97t vehicle configurations.

• NOx emissions are increased for all three engines as a result of the change in vehicle load. NOx emissions increase 42-56% for the steady state cycle and 11-26% for the transient cycle. The relative increase in NOx over the steady state cycle is greater as absolute NOx levels reduce. The opposite is observed over the transient cycle where relative change reduces as absolute NOx levels reduce. This is suspected to be a transient airflow or EGR control effect. In addition to the effects on combustion of the transient and steady state cycles as seen with the fuel composition testing, the heavier 97t vehicle needs change down to lower gears more frequently in order to match the vehicle accelerations required by the FIGE drive cycle.

• PM emissions results are very dependant on the engine. Over the steady state test cycle, the ADR80/02 and ADR80/03 engines show an increase in PM emissions of 115% and 45%, respectively. Transient test cycle results trend similarly. The ADR80/00 engine differs from the other engines in that only a small change in PM emissions is seen with the change to 97t.

• CO2 emissions for both engines shown are increased 39-53% for the steady state and transient cycles, as would be expected, and is comparable to the change in cycle average power or work due to the increased load.

Load Effects at Steady Stateemissions rates in terms of g/h

-20%

0%

20%

40%

60%

80%

100%

120%

140%

PM NOx CO2

Incr

ease

fro

m 7

0t t

o 9

7t G

CM

ADR80/00

ADR80/02

ADR80/03

Figure 6.13 – Load Effects: Relative Change in Steady State Cycle Results


Load Effects during Transient Testingemissions rates in terms of g/h

-20%

0%

20%

40%

60%

80%

100%

120%

140%

PM NOx CO2

Incr

ease

fro

m 7

0t t

o 9

7t G

CM

ADR80/00

ADR80/02

ADR80/03

Figure 6.14 – Load Effects: Relative Change in Transient Cycle Emissions

To assess if the observed load effect trends are consistent across all three phases of the FIGE cycle, the emissions data has been examined for each phase; Urban, Rural and Motorway, Figure 6.15, Figure 6.16 and Figure 6.17 respectively.

• The actual work required of the engine for each phase of the cycle is seen to vary subtly, particularly for the transient phases and for the ADR80/00 engine. Although all three engines have very similar rated power output, thereby justifying the use of the same test cycle, they each have subtly different actual torque / speed characteristics and thus the torque whilst following the normalized drive cycle. The ADR80/00 engine torque / speed characteristic was most different (greater low speed torque), and hence for the transient urban and rural phases the work required of it is also subtly different. In the motorway phase where operation is less transient, the effects are less and the work required from each of the three engines tested was very similar.

• NOx emissions for all three engines increased the most as a response to load during the higher speed Motorway phase. This is expected to be a result of the combination of the higher increase in power demand for the motorway phase, and the less transient nature of the cycle, leading to higher combustion temperatures.

• PM emissions vary greatly with the engine being examined, as discussed above. The PM emissions are also observed to vary greatly as a consequence of the drive cycle phase. Of all the phases, the urban phase with its highly transient characteristic is the only one where all three engines show a consistent trend and a clear increase in PM emissions. The average increase in PM emissions for the urban phase is between 37 and 63%.

• CO2 emissions increase approximately in line with the work increases for each phase.


Load Effects on Urban Phase of Cycleemissions rates in terms of g/h

-50%

0%

50%

100%

150%

Work PM NOx CO2Incr

ease

fro

m 7

0t t

o 9

7t G

CM

ADR80/00

ADR80/02

ADR80/03

Figure 6.15 – Load Effects: Relative Change in Emissions during Urban Phase

Load Effects on Rural Phase of Cycleemissions rates in terms of g/h

-50%

0%

50%

100%

150%

Work PM NOx CO2Incr

ease

fro

m 7

0t t

o 9

7t G

CM

ADR80/00

ADR80/02

ADR80/03

Figure 6.16 – Load Effects: Relative Change in Emissions during Rural Phase


Load Effects on Motorway Phase of Cycleemissions rates in terms of g/h

-50%

0%

50%

100%

150%

Work PM NOx CO2Incr

ease

fro

m 7

0t t

o 9

7t G

CM

ADR80/00

ADR80/02

ADR80/03

Figure 6.17 – Load Effects: Relative Change in Emissions during Motorway Phase

6.6 Discussion: Load Effects on Heavy Duty Engine Emissions

At simulated 50% laden condition, the change between 70t and 97t vehicle configurations corresponds to a 27% increase in payload. This increase in payload corresponds to approximately a 50% increase in the average power requirement over the steady state and transient drive cycles. CO2 emissions increase approximately in line with the change in power requirements.

NOx emissions are generally increased by between 25 and 50%, (1x to 2x the payload increase) depending primarily on test type.

PM emission increases are observed to be between zero and 100% (that is up to 4x the payload increase). PM emissions are seen to vary significantly between engines, test type (steady state or transient) and phases of the transient drive cycle. PM emissions by their very nature are the result of more complicated formation mechanisms and are controlled at the engine by the injection system specification and engine management system calibration, and in the case of the ADR80/03 engine, the exhaust aftertreatment system.

In the Urban phase of the transient cycle, where the average engine loads is the lowest, all three engines behave as could be expected, with both NOx and PM emissions rising as a response to increased load. However, in the Rural and Motorway phases with higher average engine loads, the ADR80/00 engine’s PM emissions appear not to increase in response to engine load. This may be an indication that at the higher engine loads, the engine has been optimised to keep visible smoke to a target value. This would limit PM emissions and could have fuel consumption benefits, but would have an adverse impact on absolute NOx emission levels. Although it was not measured, the visible smoke from the ADR80/00 engine was observed to be lower than the ADR80/02 engine during transient testing.


Given the lower absolute NOx emissions limits that the ADR80/02 engine would have had to meet, it may have only a small margin on PM, and hence PM emissions increase with increasing load.

The ADR80/03 engine is likely to have been equally constrained by its even lower NOx emissions limit, but the exhaust aftertreatment system effectively reduces the PM emissions.


7 CONCLUSIONS

The study tested five different diesel engine fuels which were differentiated by their cetane number. However, cetane number is just one of the properties of diesel fuel. With perhaps the exception of additives, changes in cetane do not occur in isolation of the change to other fuel properties such as aromatics and density. This makes it difficult to segregate what effects are due to cetane alone, and which may be the result of a combination of properties.

Table 7.1 summarises the average emission trends in response to the use of the different fuels tested in this study. Rather than give specific results, the table summarises whether a change was observed and whether it was considered real. A marginal response is assigned one + or -. A comparably significant change assigned more than one +/-. If the response is completely within the experimental scatter a ~ is indicated. Given that testing in most cases consisted of only two results per fuel, a robust statistical analysis was not possible.

From an air quality perspective, two questions can be asked:

How does a particular fuel effect engine emissions?

Is a particular engine (and its associated technology) sensitive to a particular fuel?

What Table 7.1 suggests is that the two questions must be considered together since engine technology would appear to have a significant impact on the fuel test outcome. Engine technology refers to the approach the manufacturer has taken in controlling emissions, in particular NOx and PM; the primary pollutants of interest from a heavy duty diesel engine. The engine technology itself may respond differently under steady state and transient conditions, thereby making the emission trends sensitive to the test cycle used to quantify the emissions impact.

Whilst specific differences for the fuel types are detailed in this report, the general trend observed was that for NOx and PM emissions, any changes tended to be larger for the ADR80/00 and ADR80/02 engines than for the ADR80/03 engine. Changes in CO2 emissions observed were slight, but did not appear to be correlated to engine technology.

The ADR80/00 engine represents the oldest technology in this study. This engine had no exhaust aftertreatment (DPF) for management of PM, and nor did it utilise EGR for NOx control.

The ADR80/03 engine represents the newest technology in this study. This engine had an exhaust aftertreatment (DPF) for the post-engine management of PM, EGR for NOx control and a variable geometry turbocharger (VGT) for airflow management.

The ADR80/02 engine represents a mid-way technology, which utilises EGR for NOx control and a variable geometry turbocharger (VGT) for airflow management but has no aftertreatment (DPF) for the management of PM.

It appears that the use of increasingly sophisticated emissions management systems on modern engines may be improving their robustness to variations in fuel properties. For example, the DPF equipped ADR80/03 engine so significantly reduces the absolute level of PM emissions that the difference in fuel properties is not discernable or perhaps subject to secondary factors such as the condition of the DPF itself. Meanwhile, the older non-DPF engines show a greater PM sensitivity to fuel properties. Similarly, there is evidence to suggest that the EGR and VGT equipped engines potentially mask some of the fuel property effects on NOx emissions. It was noted that NOx emissions were


often observed to trend differently when tested over steady state and transient cycles. This characteristic is suspected to be function of the transient control of the emission systems and thermal soak conditions. Where differences are seen between transient and steady state testing results, the real world effects of the fuel properties could be expected to depend largely on a vehicle’s specific duty cycle.

Fuel comparison

Test Cycle

ADR80/00 ADR80/02 ADR80/03 Overall

ESC NOx +

PM -

CO2 - -

NOx +

PM - -

CO2 -

NOx +

PM -

CO2 -

NOx ▲

PM ▼

CO2 ▼

Diesel Low High Cetane

ETC NOx -

PM - -

CO2 - -

NOx -

PM -

CO2 - -

NOx -

PM +

CO2 +

NOx ▼

PM ▼

CO2 ▼

ESC NOx -

PM - -

CO2 +

NOx -

PM - -

CO2 +

NOx -

PM +

CO2 +

NOx ▼

PM ▼▼

CO2 ▲

Biodiesel

B0 B20

(ignoring B5 which is seen to not always lie between B0 and B20)

ETC NOx +

PM - -

CO2 +

NOx +

PM - -

CO2 +

NOx +

PM -

CO2 -

NOx ▲

PM ▼▼

CO2 ▲

ESC NOx -

PM - -

CO2 - -

NOx ~

PM -

CO2 - -

NOx ~

PM +

CO2 - -

NOx ???

PM ▼▼

CO2 ▼▼

Diesel R50

(R50 is low density synthetic diesel)

ETC NOx - -

PM - -

CO2 - -

NOx ~

PM ~

CO2 - -

NOx ~

PM ~

CO2 - -

NOx ???

PM ???

CO2 ▼▼

ESC NOx yes

PM yes

CO2 yes

NOx yes

PM maybe

CO2 yes

NOx maybe

PM no

CO2 yes

Overall, is engine sensitive to differences in fuel properties?

ETC NOx yes

PM yes

CO2 yes

NOx yes

PM yes

CO2 yes

NOx maybe

PM no

CO2 maybe

Table 7.1 – Summary of Fuel Effects on Heavy Diesel Engine Emissions

The testing of the effect of engine load on emissions showed a more conclusive result for NOx emissions, but not so for PM. Vehicle GCM was increased from 70t to 97t and operation simulated at the 50% laden condition resulting in an increase in payload by an


estimated 27%. This simulated change resulted in an increase to the total engine power output required to follow the specific FIGE vehicle drive cycle by 40-50%†.

The effects of engine load on emissions can be summarised as:

NOx emissions were found to increase by between 25 and 50%, depending on whether the assessment was undertaken by steady state or transient test cycles.

The effect of increased GCM on PM2.5 emissions was engine and cycle dependant. PM emissions from the ADR80/02 engine more than doubled for most tests with the increased GCM. PM emissions from the ADR80/03 engine also showed a significant increase, though having been fitted with a DPF exhaust aftertreatment the absolute level of the emissions was much smaller. There were only minor effects on PM emissions for the oldest ADR80/00 model engine.

CO2 emissions were found to increase in-line with the power required by the drive cycle

† A change to 100% laden does not proportionally increase the power requirement since the vehicle configuration consists of vehicle mass plus payload.


8 REFERENCES

[1] ASTM D4737 - 09a Standard Test Method for Calculated Cetane Index by

Four Variable Equation, http://www.astm.org/Standards/D4737.htm

[2] ASTM D6890 - 09 Standard Test Method for Determination of Ignition Delay

and Derived Cetane Number (DCN) of Diesel Fuel Oils by Combustion in a

Constant Volume Chamber, http://www.astm.org/Standards/D6890.htm

[3] Fuel Standard (Automotive Diesel) Determination 2001 http://www.frli.gov.au/ComLaw/Legislation/LegislativeInstrumentCompilation1.nsf/current/bytitle/1EBAA88F854F4581CA25756600154F2A?OpenDocument&mostrecent=1

[4] ASTM D613 - 10 Standard Test Method for Cetane Number of Diesel Fuel Oil, http://www.astm.org/Standards/D613.htm

[5] ADR70/00, Motor Vehicles Standards Act, 1989 Australian Design Rule 70/00

– Exhaust Emission Control for Diesel Engined Vehicles

[6] “Diesel Emissions and Their Control” SAE International 2006 ISBN978-

076800674-2

[7] Setting national Fuel Quality Standards- Paper 6. National Standard for

Biodiesel – Discussion Paper. Prepared by Environment Australia, March

2003.

[8] “Automotive Fuels Handbook” SAE international 1990 ISBN 1-56091-064-X

[9] http://www.dieselnet.com/tech/fuel_emi.html#heavy

[10] ADR80/00, Motor Vehicles Standards Act, 1989 Australian Design Rule 80/00 - Emissions Control for Heavy Vehicles

[11] ADR80/01, Motor Vehicles Standards Act, 1989 Australian Design Rule 80/01

- Emission Control for Heavy Vehicles) 2005



[14] United States Code of Federal regulations (CFR) Part 86 – Control of air pollution from new and in-use motor vehicles and new and in-use motor vehicles engines certifications and test procedures – Subpart A 40. http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&tpl=/ecfrbrowse/Title40/40cfr86_main_02.tpl

[15] Delphi Worldwide Emissions Standards, 2008 Heavy Duty and Off-Road Vehicles, http://delphi.com/manufacturers/auto/powertrain/emissions_standards/

[16] MDLT-1300T Series Partial Flow Particulate Sampling System, Horiba Group.

http://www.horiba.com/automotive-test-systems/products/emission-

measurement-systems/dilution-sampling-systems/details/mdlt-1300t-876/


[17] Development of On Track Chassis Dynamometer Drive Cycles and Subsequent Evaluation Of Sensors Europe On Board Emissions Sampling System. UK Department For Transport, 2003 Report Number MBK 03/0592 http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/pgr/roads/environment/research/cqvcf/ardemissionsmeasurements3837.pdf

[18] Heavy-Duty Truck Emissions and Fuel Consumption Simulating Real-World Driving in Laboratory Conditions, 2005 DEER Conference, VVT Technical Research Centre of Finland, August 2005

[19] ADR79/02, Motor Vehicles Standards Act, 1989 Australian Design Rule 79/02- Emissions Control for Light Vehicles

[20] A Reference Book of Driving Cycles for Use in the Measurement of Road vehicle Emissions. TJ Barlow, S Latham, IS McCrae and PG Boulter. TRL Ltd PPR354 http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/pgr/roads/environment/emissions/ppr354.pdf

[21] Motor Vehicles Standards Act, 1989 Australian Design Rule 79/00 - Emissions Control for Light Vehicles

[22] http://www.dieselnet.com/standards/cycles/etc.html


Appendix 1. Fuel Analysis Datasheets

A quality assurance analysis was undertaken on all project fuels at the commencement the study. The results from these tests are included in this appendix.

Low Cetane Diesel 87

High Cetane Diesel 89

B5 Biodiesel 93

B20 Biodiesel 95

R50 Renewable Diesel 97

B100 Diesel – used only to prepare B5 and B20 99


Low Cetane Diesel


High Cetane Diesel


Independent Analysis of DCN for High and Low Cetane fuels Sample IDs

Low Cetane Fuel: 42848-2, 42848-3 High Cetane Fuel: 42848-1, 42848-4


B5 Diesel


B20 Diesel


R50 Diesel


B100 Diesel – used only to prepare B5 and B20


Appendix 2. Prime Mover Specifications (extract only)

Prime-mover to suit 70tonne Service KENWORTH DAF WA A060 787 Abernethy Road FORRESTFIELD, WA Australia 6058 , Phone: 0893597400 Phone: Fax: 0893528222 Fax: Email: [email protected] Email: Prepared for:

Vehicle Summary

Unit Chassis Model: T402 Fr Axle Load (kg): 6000Type: Prime Mover Max Front Load (kg): 6500Description: Orbital 70T Distance at Max Load (%): 2

Application Rr Axle Load (kg): 16000Intended Serv.: General Freight Max Rear Load (kg): 16500Commodity: General Freight Distance at Max Rear Load (%): 2 G.C.M. (kg): 42500

Body Max G.C.M. Load (kg): 70000Type: Distance at Max G.C.M. Load (%): 2Length (mm): 0 Wheelbase (mm): 6500Height (mm): 0 Fr Axle to BOC (mm): 2,490Body Weight (kg): 0 Cab to Axle (mm): 4,010Body Width (mm): 0 Cab to EOF (mm): 7,010

Trailer Road Conditions: No. of Trailer Axles: Class A (I’state hwy/Roads): 100Type: Flatbed Class B (Well maintained): 0Length (mm): 0 Class C (Poorly maintained): 0Height (mm): 0 Class D (Off-Road): 0Kingpin Inset (mm): 0 Maximum Grade: 10Corner Radius (mm): 0 Length Max Grade (km): 2Trailer Width (mm): 0 Normal Grade (%): 4

Restrictions Length Normal Grade (km): 2Length (mm): 19000 Annual Distance (km): 200000Width (mm): 2500 Height (mm): 4300 Special Req. Australia Wide

Approved by: Date:

Unpublished options may require review/approval. Dimensional and performance data for unpublished options may vary from that displayed in PROSPECTOR.

Printed: 13/11/2009 10:35:51 AM Incomplete Model Number: T402

Effective Date: Jul 1, 2009 Quote/DTPO/CO: Q63506355

Prepared by: Kurt Smith Version Number: 14.10


KENWORTH DAF WA A060 787 Abernethy Road FORRESTFIELD, WA Australia 6058 , Phone: 0893597400 Phone: Fax: 0893528222 Fax: Email: [email protected] Email: Prepared for:

Description Weight

Model T402 8,078

Engine & Equipment Cummins ISX EGR 450.465hp 0

THIS ENGINE IS NOT ABLE TO BE UP-RATED. (@ 1600rpm, 1650lbft torque @ 1200prm. 15.0 litre displacement. Six cylinder in-line turbocharged air-to-air aftercooled 813mm diameter fan. Aluminium flywheel housing. Fleetguard combination full flow and by-pass oil filters and itegral oil cooler).

2000rpm maximum 0 (ISX or Signature)

Transmission & Clutch Fuller RTLO18918B, 1850lbft torque 0

18 speed O'drive

Axles & Equipment

REAR AXLE RATIO-4.30 0

Tyres & Wheels Bridgestone 295/80 R22.5 R150-II 0

- 2 steer

Bridgestone 11R22.5 M722 0

Total Weight 8945kg

Prices and Specifications Subject to Change Without Notice.

Typical accuracy of a weight estimate is +/- 2% and does not include the weight of fuel. There is no guarantee as to the accuracy of the weight estimate of this specification.


Printed: 13/11/2009 10:35:51 AM Incomplete Model Number: T402




Prime-mover to suit 100tonne Service


Vehicle Summary

Unit Chassis Model: K108 Fr Axle Load (kg): 6000Type: Prime Mover Max Front Load (kg): 6500Description: Orbital Corp 100T Distance at Max Load (%): 50

Application Rr Axle Load (kg): 16500Intended Serv.: General Freight Max Rear Load (kg): 16500Commodity: General Freight Distance at Max Rear Load (%): 50 G.C.M. (kg): 42500

Body Max G.C.M. Load (kg): 97000Type: Distance at Max G.C.M. Load (%): 10Length (mm): 0 Wheelbase (mm): 4280Height (mm): 0 Fr Axle to BOC (mm): 1,360Body Weight (kg): 0 Cab to Axle (mm): 2,920Body Width (mm): 0 Cab to EOF (mm): 4,290

Trailer Road Conditions: No. of Trailer Axles: Class A (I’state hwy/Roads): 100Type: Flat Top Class B (Well maintained): 0Length (mm): 20800 Class C (Poorly maintained): 0Height (mm): 4300 Class D (Off-Road): 0Kingpin Inset (mm): 1430 Maximum Grade: 8Corner Radius (mm): 0 Length Max Grade (km): 1Trailer Width (mm): 2500 Normal Grade (%): 2

Restrictions Length Normal Grade (km): 1Length (mm): 26000 Annual Distance (km): 250000Width (mm): 2500 Height (mm): 4300 Special Req. Australia Wide

Approved by: Date:


Printed: 13/11/2009 10:28:13 AM Incomplete Model Number: K108





Description Weight

Model K108 8,478

Engine & Equipment Cummins ISX EGR 525.550hp 0

@ 1600-1800rpm, 1850lbft torque @ 1200prm. 15.0 litre displacement. Six cylinder in-line turbocharged air-to-air aftercooled 813mm diameter fan. Aluminium flywheel housing. Fleetguard combination full flow and by-pass oil filters and itegral oil cooler.

2000rpm maximum 0 (ISX or Signature)

Transmission & Clutch Fuller RTLO20918B, 2050lbft torque 0

18 speed O'drive

Axles & Equipment

REAR AXLE RATIO-4.30 0Tyres & Wheels

Bridgestone 295/80 R22.5 R150-II 0 - 2 steer

Bridgestone 11R22.5 M722 0

Total Weight 9108kg

Prices and Specifications Subject to Change Without Notice.

Typical accuracy of a weight estimate is +/- 2% and does not include the weight of fuel. There is no guarantee as to the accuracy of the weight estimate of this specification.


Printed: 13/11/2009 10:28:13 AM Incomplete Model Number: K108



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