technical report templates - wrap report.docx · web viewfinal report : propane blending system...

Final report

Propane blending system for biomethane to grid applications

Low cost propane blending system for biomethane to grid schemes, transfer of technology from other industries.

Project code: OIN001-011 ISBN: [Add reference] Research date: 2013 Date: 2013/14

Propane blending system for biomethane to grid applications 2

WRAP’s vision is a world without waste, where resources are used sustainably.

We work with businesses, individuals and communities to help them reap the benefits of reducing waste, developing sustainable products and using resources in an efficient way.

Find out more at www.wrap.org.uk

Written by: Terry Williamson, CNG Services Ltd

Front cover photography: Gas ring

While we have tried to make sure this [plan] is accurate, we cannot accept responsibility or be held legally responsible for any loss or damage arising out of or in connection with this information being inaccurate, incomplete or misleading. This material is copyrighted. You can copy it free of charge as long as the material is accurate and not used in a misleading context. You must identify the source of the material and acknowledge our copyright. You must not use material to endorse or suggest we have endorsed a commercial product or service. For more details please see our terms and conditions on our website at www.wrap.org.uk

http://www.wrap.org.uk/

Executive SummaryThere exists an opportunity for the supply of a low cost propane blending system for biomethane to grid schemes which are to inject into the 2 Bar gas grid. This includes the majority of small scale projects which can be expected to have a biomethane flow of less than 100 Sm3/hr (at 1013 mB and 15°C) and be located close to a two Bar grid.

Propane blending systems require good accuracy coupled with excellent reliability. They operate within UK ambient temperatures (-20 to + 45 oC) and to stable operating conditions. Traditionally they use high value components manufactured in relatively low volumes that need to be carefully assembled and tested by trained staff.

Automotive products also require good accuracy with excellent reliability but within an extreme environment involving significant temperature swings (-40 to +120 C under bonnet temperatures) and highly cyclic duty cycles with significant resistance to impact. Traditionally they use components robustly built to a highly competitive price in large volumes. Components are available conforming to EU standards R67, R110 and ISO 15500.

This project explores the potential of using automotive parts to construct a propane blending system for anaerobic digestion facilities operating a biomethane to grid process. By using parts from an industrial environment the project will take advantage of high quality parts which are at a very low cost. The systems may be compact (designed to fit under the bonnet of the average car) and easily assembled using components rated at the expected gas pressures involved.

The final innovation is to use the expensive Programmable Logic Control (PLC) installed as part of the gas quality monitoring scheme in the entry facilities to provide control on the rate of propane injection.

Utilising automotive components and an existing PLC reduces the cost for the propane injection system to around £20k from the current £80 - £100k and represents a significant cost reduction that can help the economics of small scale biomethane to grid projects


Contents1 Introduction and background......................................................4

1.1 The issue.............................................................................................41.2 Objectives...........................................................................................41.3 Introduction........................................................................................41.4 Project explanation.............................................................................51.5 Company description..........................................................................5

2 Technical appraisal and Phase 1 methodology..............................52.1 Biomethane and the gas grid..............................................................52.2 Propane storage..................................................................................62.3 Propane blending system....................................................................62.4 Development of an automotive component-based system.................82.5 Technology considerations for Phase 2.............................................10

2.5.1 Identified risk - Non-compliant with ATEX No 1 (EX rating).....102.5.2 Non-compliant with ATEX No 2................................................102.5.3 System pressures....................................................................102.5.4 Component durability..............................................................11

2.6 Laboratory testing............................................................................112.6.1 The laboratory unit control system.........................................12

3 Preparations for Phase 2: Demonstration of the propane blending system.............................................................................................12

3.1 What we need to do in Phase 2.........................................................133.2 Mass balance....................................................................................13

4 Legislation...............................................................................145 Commercialisation....................................................................14

5.1 IP.......................................................................................................145.2 Commercialisation plans...................................................................155.3 Manufacturing plans.........................................................................15

6 Conclusion................................................................................157 Phase 2 Demonstrations............................................................17

7.1 Objectives.........................................................................................177.2 Methodology.....................................................................................17

7.2.1 Summary of activity................................................................177.2.2 Project Milestones...................................................................17

7.3 Stakeholders.....................................................................................177.4 Project Timescale..............................................................................187.5 Economics.........................................................................................19

7.5.1 Project costs............................................................................197.5.2 Financing.................................................................................20

7.6 Evaluation and monitoring................................................................207.7 HSE...................................................................................................20

Appendix 1 Calculations...................................................................21Appendix 2.......................................................................................23

A2.1 Component evaluation......................................................................23Appendix 3 Properties of propane.....................................................25Appendix 4 P&ID gaseous phase propane blending system.................26Appendix 5 Propane blending system control description...................27

A5.1 Overview...........................................................................................27A5.2 Propane blending..............................................................................27A5.3 Temperature control and vaporisation..............................................28A5.4 Pressure control................................................................................28A5.5 Temperature control.........................................................................29A5.6 Functional control.............................................................................29

Appendix 6 References.....................................................................30


A6.1 Part 1 - Gas industry.........................................................................30A6.1.1.......................................................................................................Legislation

30A6.1.2................................................Gas distribution network specifications

30A6.1.3..........................................................................................British Standards

31A6.1.4.....................................................................................European standards

32A6.1.5................Institution of gas engineers and managers publications

32A6.2 Part 2 - Automotive, industrial engine..............................................33

A6.2.1.......................................................................................................Legislation33

A6.2.2...................................................................................................Environment33

A6.2.3.....................................................................................European standards33

A6.2.4..............................................................................International standards33

Appendix 7 Typical automotive LPG components................................34Appendix 8 Product costs for commercialisation................................40

List of figures Figure 1 Propane blending gaseous system...........................................................7Figure 2 Propane blending liquid injection system.................................................7Figure 3: Capex of Clean-up system.......................................................................8Figure 4: Project timescale...................................................................................17

List of tables Table 1: Electrical Energy Consumed by the Control System...............................13Table 2: Propane blending system costs..............................................................15Table 3: Project costs...........................................................................................18Table 4: Project cost sharing................................................................................19Table 5: List of devices to measure and control...................................................27

GlossaryADcapexCHPCVLPGOfgemopex


Sm3/hrVP

1 Introduction and background

1.1 The issue

The capital costs for construction of an anaerobic digestion (AD) plant, the upgrading of biogas to biomethane and delivering that biomethane to the gas grid are expensive operations. To make them more affordable and sustainable in the long term without resorting to subsidies requires that capital and operating costs are reduced. For a small project e.g. 100 Sm3/hr of biomethane, the propane blending plant represents around 75% of the overall Biomethane to Grid Capex and hence a reduction here will be of particular benefit. Transferrable technology also offers a way forward for the industry as a whole, and can provide more competition which will reduce the cost of propane.

Propane blending systems are offered by most of the biogas upgrading plant manufacturers and UK LPG suppliers, Calor, Shell and Flogas. However, in the biomethane market, only Flogas is active in UK projects. Flogas offers both gaseous and liquid blending systems at a cost of some £80,000 to £120,000 excluding the cost of the storage tanks. This project is reviewing the scope of reducing the cost of such systems by utilising mass produced components.

1.2 Objectives

Traditional equipment to measure and blend propane into a biomethane stream to enhance the CV of the gas is based on components designed and constructed for the process and gas industry. They are robust and durable, but expensive, primarily due to the relatively low production volumes. The objective of this study is to identify components and methods used in the automotive industry for the purpose of constructing a propane blending system. That system will offer similar performance to traditional blending systems while taking advantage of substantially reduced component costs. To achieve the objective three primary areas will be addressed in the feasibility study, namely:

Determining the technical needs of the system Assessing the suitability of the identified components and their impact on

overall system cost Outlining the requirements for market acceptability in terms of testing and

validation

1.3 Introduction

LPG (a blend of propane and butane) has been used in the automotive, off highway (fork lift truck) and stationary engine industry for over 80 years. Its evolution has produced components that are safe and dependable at very low cost in huge quantities in all major countries of the world.

In industry, LPG is used to raise steam and for process loads where there is no natural gas available. In the domestic market, LPG is widely used for heating and cooking in areas where there is no gas grid or for portable equipment.


A typical flow weighted average CV for the gas grid is 39 MJ/m3. The CV of 98% methane (typical biomethane) is 37.0 MJ/m3. To increase the CV of the biomethane to the grid average, as required by Ofgem, thus requires around 10% propane energy. There are three costs associated with this:

Propane control computer and injection system (capex) Propane storage (capex) Propane value loss (opex) - being the difference between the cost of

propane and its value as natural gas

This project aims to reduce the cost of the propane control computer and injection system from £80K to around £20K with no loss of accuracy and reliability.

1.4 Project explanation

DIAD Round II aims to bring innovative technologies to the AD sector so they can be adopted by new and/or existing AD plants. The programme is focussed on the following four work streams:

1. Scaling Technology 2. Processing and enhancing digestate3. Using Heat from AD 4. Proof of Market, AD Technologies

The overall objective of the DIAD programme is to challenge the cost of AD operations and introduce new technologies to improve operational efficiencies and costs.

This project is a technical review looking at a theoretical functional design for a system based around some key automotive components with the addition of process components where automotive parts are not available. The study scopes the components, design and relative sizes to see where it fits into the biomethane to grid industry and identifies what gas grid pressures and flow rates it can accommodate.

1.5 Company description

CNG Services Ltd (CSL) is a leading company in the AD and biomethane industry providing engineering services in relation to the development of new anaerobic digester projects including; electricity generation via CHP, clean-up of biogas to produce biomethane and its injection into the gas distribution network and use of compressed biomethane as a vehicle fuel.

2 Technical appraisal and Phase 1 methodology

2.1 Biomethane and the gas grid

Biomethane is predominately methane with some inert gasses (carbon dioxide (CO2), Nitrogen (N2) and Oxygen (O2) etc.); its gross CV is typically in the region of 36 to 37 MJ/Sm3 (at 1013 mB and 15°C)


The UK gas grid has a CV range of between 37.5 and 43 MJ/Sm3 so when injecting biomethane it will always require its CV to be enhanced to match the CV of the grid. There are exceptional circumstances when this may not be necessary due to blending but in most cases enrichment is required.

CV enhancement is achieved by blending a controlled volume of propane, the CV of which is typically 92 MJ/Sm3 with the biomethane. Typical blending quantities are some 4% by volume or 10% by energy.

Gas grids are arranged in a series of pressure tiers, each system supplying a lower pressure tier down to the point of delivery to an industrial or domestic system.

UK pressure tiers are as follows:

LP Low Pressure, 100 mBar or less MP Medium Pressure, 1 to 2 Bar IP Intermediate Pressure, 4 to 7 Bar LTS Local Transmission System, 10 - 40 Bar.

Most biomethane to grid systems currently under development fall into the MP and IP pressure range, the majority being MP. For the purpose of this study the 2 and 7 Bar pressure levels only will be considered.

For injection into the LTS there is a compressor after the propane injection system and hence there is never a requirement to inject propane into a biomethane stream at >7 bar.

2.2 Propane storage

Storage vessels for this system are usually bulk refillable tanks from 1 tonne capacity upward and are sited above ground or sometimes buried. Above ground tanks are exposed to UK weather so a range of temperatures of – 5°C to + 40°C are considered (the + 40°C considers the impact of solar gain heating the tank). Buried tanks will have a lesser variation so we could consider + 5°C to + 25°C, this falls within the above ground storage so we will work with the – 5°C to + 40°C range.

Propane storage temperatures are important in that they set the in-tank vapour pressure (VP) likely to be seen. Referring to the chart in Appendix 3 we can see that at – 5°C (268 K) VP is 4.2 Bar and 40°C (313K) VP is 15 Bar. Understanding the VP is important in that it is the pressure available to push liquid propane out of the tank towards the blending system. If the pressure required at the delivery point is above the tank VP then additional measures are needed to deliver propane. We could heat the tank with hot water to raise the temperature (and the VP) or use a mechanical pump. Hot water would be preferred as this is often available as a waste energy within other parts of the system.

Low pressure systems (< 2Bar) are unlikely to require additional propane heating or pumping but to achieve an in-tank VP of 8 Bar (to allow a margin for downstream processing) it requires a temperature of 290K (17°C), so heating or pumping would be needed some of the time.

Propane is delivered by a pipe, sized to cope with the expected flow rate at minimum VP to the main system.


2.3 Propane blending system

Existing systems are mainly based on the concept of taking liquid from a storage tank, vaporising (turning the liquid into a gas) it in a heated chamber using electrical elements or heat from a source such as the cooling water system of a compressor and delivering it to a mixing chamber in through a control valve. Biomethane CV is measured upstream of the mixing chamber, the required volume of propane to be introduced is calculated and the quantity of propane flowing to the mixer is measured. The control valve responds to the measured amount in order to introduce the correct volume. Temperatures and pressures are taken into account to compensate for variations. Gas CV is measured again downstream of the blending unit and compared with a target value, any difference is fed back to the control system and propane flow is adjusted.

A newer version of a propane blending scheme is based on injecting liquid propane directly into the biomethane stream, this action causes the liquid to turn into a gas but by doing so absorbs heat from the biomethane, the resultant blend requires re-heating to a temperature suitable for grid injection. In all other respects control principal is the same.

Propane blending schemes. Conceptually the same functionality will be followed for this study. The following figures illustrate two methods of introducing propane into a biomethane gas stream.

Figure 1 Propane blending gaseous system.

Gas is introduced either by using a gas/gas mixer (think carburettor) or by using a pulsed injector into the gas stream (think fuel injector).


Figure 2 Propane blending liquid injection system.

Gas is introduced as a liquid, the flow is varied by altering the flow from a pump or modulating vapour pressure in the storage vessel by controlled heating and varying flow in a flow control valve. The pressurised liquid is then injected where it vaporises in the biomethane stream due to lower pressure in the gas stream. The gas stream then requires heating to ensure propane remains a gas and does not condense out. Automotive systems have been developed using this technique in the past but no recent market activity has been noted so the concept is presented for illustrative purposes only. The advantage of such a system is that much higher operating pressures can be employed.

More information on how a system operates may be found in Appendix 2

2.4 Development of an automotive component-based system

To assess how to go about the development of a system we first need to understand the overall needs and set out deliverables, this in turn leads us to a scale for a typical system or range of systems and concepts.

Targeting small scale biomethane projects we need to understand what range of grid capacities and pressures should be looked at. We suggest 2 and 7 Bar pressures for the reasons given in 2.1 and a biogas flow of 500 Sm3/hr or under. The chart below came out of a study of upgrade technologies and indicates that costs start to climb at flows less than this so it is the sub 500 range where cost savings are most important.


0 500 1000 1500 2000 2500 3000 35000.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Capex/m3 biogasPower (Capex/m3 biogas)Power (Capex/m3 biogas)

Biogas flow m3/hr

Cape

x £

000'

s/m

3 ca

pacit

y

R2=0.9137

Figure 3: Capex of Clean-up system

A 500 m3/hr the biogas flow would deliver about 300 m3/hr of biomethane to the gas grid so we need to review components able to blend about 6% by flow of propane (18 Sm3/hr). The 6% is arrived at by taking the difference between a relatively low CV biomethane (36MJ/Sm3) and natural gas (39.5 MJ/Sm3) and calculating how much propane (91MJ/Sm3) is required to enhance the biomethane CV by 3.5MJ

System measurement and control accuracy generally accepted within the biomethane industry is +/- 1MJ for CV and volume flow needs to meet fiscal accuracy +/-1% +0.5% full-scale. The CV accuracy is required to ensure that gas being delivered does not reasonably under-deliver gas energy to the consumer and the flow accuracy is required to demonstrate to Ofgem that the volume of propane used and therefore offset against the RHI (Renewable Heat Incentive) is adequately recorded. The explanation for this is that the RHI is only payable on exported energy wholly derived from renewable sources, propane does not meet this requirement so any propane energy introduced is deducted from the total exported energy.

Propane needs to be heated to ensure it is able to meet pressure demands with no opportunity condense out in vapour phase systems. Heat ideally is collected from a circuit that otherwise would go to waste i.e biogas compressor cooling circuit or CHP

We now know that we need to specify a system which can enable a flow of up to 18 Sm3/hr of propane at up to 7 Bar into 300m3/hr of biomethane with CV and propane flow accuracy as stated above. Appendix 1 shows calculations for typical automotive components and indicates that a propane flow rate sufficient to blend into 1,300 Sm3/hr of biomethane is readily achievable so easily exceeds our target of 300 Sm3/hr

Having determined the design objectives we have developed a conceptual PID of a system (see Appendix 4). This shows all components required for a vapour phase system to function. It is now a matter of identifying what components may be of Automotive source and those that may not.


2.5 Technology considerations for Phase 2 This section identifies those areas where there are issues with meeting project requirements in Phase 2. Comments are made on the issue and a proposed solution, if any.

2.5.1 Identified risk - Non-compliant with ATEX No 1 (EX rating)Equipment that allows the flow of, or handles combustible gases and liquids in a location coexisting with equipment able to create a spark normally needs to comply with ATEX or EX requirement. i.e. should a leak occur, there will not be a source of ignition (spark from a switch or electric motor). All electrical components and the installation shall be shielded to prevent a spark reaching the gas should an electrical fault occur.

Automotive engines and components operate in an environment where ATEX would normally apply, but because it is a vehicle it falls under UK SI2884 and ECE R110 regulations, the use of non ATEX equipment is normal practice. i.e electrical components are not protected to prevent sparking.

By its nature a vehicle (car, bus, truck or fork-lift truck) is manned during operation so may be switched off at any time. In the event of an accident gas fuel systems are closed off automatically (usually by an impact switch closing off a gas valve). Pressure and thermal gas release systems are employed in event of a fire.

2.5.2 Non-compliant with ATEX No 2Stationary gas engines operate in an environment that would normally fit into the Zone 2 category and therefore be ATEX compliant. However there is no requirement to do so and electrical components are not normally protected. By its very nature a gas engine has to spark to create ignition and there is a high probability of arcing over from high tension plug leads producing a ready source of gas leak ignition

In this instance a DSEAR study is normally carried out. This reviews safety of an installation, it is usually acceptable to monitor for gas leaks and have shut down and ventilation schemes to minimise a hazardous condition should a gas leak occur. Gas is exhausted via an ATEX compliant fan that will continue to operate after a gas leak has been detected and the engine safely shut down.

By applying the same thinking to a propane mixing system to that of a stationary gas engine it is possible to use non ATEX equipment and so pave the way for using automotive parts. This approach would be as stationary gas engines and include safety interlocks, shutdown and ventilation in the event of a gas escape to provide a safe application.

There is a high risk of non-compliance as this approach would not normally be accepted and may take considerable work to design in and demonstrate that the approach is acceptable. There is less risk of a gas leak and spark creation in a propane blending system than there ever is from a gas engine. The issue would be to present a convincing case to those responsible for carrying out the DSEAR study.

Acceptance would allow the project to proceed, failure would curtail the project.


2.5.3 System pressuresThe gas grid pressure tiers given in 2.1 indicate 2 and 7 Bar.

Automotive components are designed to work with typical engine turbochargers where 2 Bar G pressures would be a maximum. This is likely to preclude use with a 7 Bar system.

Use of a liquid injection system would overcome this limitation but it is likely to preclude the use of automotive components. It is likely therefore that an automotive system will have to focus on a 2 bar system.

2.5.4 Component durabilityThis is an important feature of any design. All systems will require a level of maintenance and the key is to assess likely failure rate and service or replace components within the expected life cycle. Here we assess component life to consider their usefulness and to fix service intervals. The main automotive components identified that could replace traditional parts are shown in Appendix 7:

Gas regulators and calorifiers (gas vaporisers). These are designed and expected to last without repair for some 100,000 to 600,000 miles. Taking an average speed of 30 m.p.h then expected durability in terms of continuous operating hours would be 3,000 to 20,000, or 4 months to 2 years. As long as the part can reliably exceed the time between annual service then it’s use would be acceptable.

Injectors, gaseous or liquid. We know that automotive gas injectors1 are rated for some 290 million cycles. If these are arranged in a ring of 6 in the biomethane stream and pulsed for 0.25 seconds each so that at any one time one injector is open and passing propane then system durability calculates at 120,000 hours. This system could be easier to validate, the critical issue is injector heating (due to current flow in the injector coil) and therefore opening time, keeping these within limits can be achieved by increasing the number of injectors in the system.

Gas flow control valves. A typical component is made by Woodward controls and used extensively in gas CHP units, their durability is not given in the specification data but from practical experience is known to be comparable with process equipment.

2.6 Laboratory testing

Testing in a laboratory during the demonstration phase is necessary to establish proof of concept. This will allow functional testing to establish whether adequate system control can be achieved.

The main issues to consider are as follows. More information is given in Phase 2.

Propane flow capacity. Are the components able to provide a flow of the required quantity of gas consistently, do they meet the design specification for the components and can the system be up scaled to meet industry needs?

1 Keihin Corporation injector test performance criteria. Quantum injector test criteria.


Propane flow control. Does the control system meet the gas blending tolerances required and will it do this over the range of temperatures and pressures expected?

Product life cycle testing. Although this is outside the scope of this project, a view needs to be taken from component manufacturers with a factor assessed for use in this industry. The prime difference is that industrial components have a significantly easier life than those in vehicles. Temperature variation is minimal -5 to + 40 C (vehicles are designed for -40 + 125 C under-bonnet temperatures). Operating cycles are steady state, little flow variation from day to day, a vehicle application is violently transient. A steady state condition (in a propane blending system) may increase service life by x 10.

2.6.1 The laboratory unit control system

Construction of a test system during the demonstration phase will require a bespoke control unit designed and manufactured specifically for testing the system. This is necessary because at the present time propane blending control units are stand-alone devices designed to meter the propane required, built for this purpose by existing manufacturers and highly unlikely to be useful in this test.

The control unit works as follows:

The biogas upgrade plant delivering biomethane to the propane blending unit provides gas CV and biomethane flow input to the control unit.

The required gas grid target CV is entered into the control unit manually or automatically.

The control unit uses the two CV’s and the biomethane flow to calculate how much propane is required to enhance the biomethane up to gas grid CV level.

The correct amount of propane is admitted into the gas stream by the flow control device receiving instruction from the control unit.

The grid entry unit screens the blended gas and confirms the CV, this signal is used to fine tune the blending unit and give more accurate results.

Further system integration and cost reduction is achievable. There is scope to integrate the propane blending control system into the grid entry unit (the point where the blended biomethane is finally measured prior to grid injection). The addition of a few extra signal inputs and control outputs into an existing system (in the biogas plant or grid entry unit) gives an opportunity to reduce system cost by some £20,000 over and above that saved by using automotive components.

The un-enriched biomethane CV and flow-rate is still obtained from the biogas upgrade plant.

The blended gas flow and CV is still obtained from the grid entry unit.

Incorporating control into one or the other units removes the need for a separate control unit.


From a technical perspective this is entirely feasible, however how to achieve this will require working with grid entry unit manufacturers in the future to persuade them to adopt this as an idea,.

3 Preparations for Phase 2: Demonstration of the propane blending system

This would occur in the Laboratory and on the ground via an operational site. The demonstration would provide proof of concept for the technology.

The aims and objectives of Phase 2 are as follows:

The primary objective is to ensure that the propane blending system is able to operate at the required pressure and achieve stable results to meet the blended CV target by +/- 1 MJ.

The system should be able to cope with fluctuations in propane bulk storage pressure (resulting from storage temperature), fluctuations in methane feed flow, temperature and CV. These would be demonstrated by heating and cooling and blending in small quantities of CO2 to the gas stream prior to propane blending.

Verify that the system can be automatically started and stopped when biomethane quality or propane delivery conditions fall outside parameters that would result in unacceptable delivery quality of the blended gas.

Verify that all of the control parameters can be altered as site conditions would require. This would include local and remote control.

3.1 What we need to do in Phase 2

Build a laboratory system outlined in section 2.6. Fully design and specify a functional demonstration unit able to

accommodate gas grid pressures up to 2 Bar. Use automotive components typically identified in Appendix 7 Construct a functional test model of table top scale and complying with the

PID given in Appendix 4 Utilise commercial methane (to simulate biomethane) available in high

pressure bottle banks at 250 Bar, pressure reduce and blend at 2 Bar to fully validate the 2 Bar design.

Devise and specify an enclosure to accommodate equipment divided into two parts.

o 1 - Non ATEX area to house the control system. o 2 - Area where combustible gas may be present to house the gas

train components, adopt CHP practice to ventilate this area using an ATEX fan and gas detection. Comply with DSEAR study.

Construct a functional control system to fully operate the plant and in conjunction with hired in equipment operate and obtain performance data.

Demonstrate that the system meets the functional specification. Combust the blended gas in a flare or hot water boiler.

A cost break-down of bought in components, test systems and labour costs are given in Appendix 8. The following paragraphs indicate some of the data required and criteria that need to be met.

3.2 Mass balance

See calculations in Appendix 1


A typical LPG vaporiser/regulator unit manufactured by Impco will enable a flow of up to 500kW of propane and require 5.71kW of heat energy (ideally derived from a renewable or recoverable source, i.e. digester circuit) to vaporise and temperature control the gas.

Overall electrical energy consumed by the control system is as follows.

Table 1: Electrical Energy Consumed by the Control System

Device Electrical energyControl system 100W estimatedFlow control valve 32W maxWater pump 1 65W maxWater pump 2 65W maxFlow control valve 5W typicalMetering 6W typicalTotal 273 W maximum.

Overall energy consumption 5,983 Watts, as described in Appendix 1.

The calculated energy requirement given here will be similar whatever technology is used.

4 Legislation

Legislation and codes of practice for gas process plants is covered in publications given in Appendix 6. These are arranged in Part 1, Gas Industry and Part 2 Automotive and stationary engines.

Overall legislation covering mobile and fixed equipment has developed along different routes, both recognising constraints in their relevant industries. The main challenge in this study is utilising non ATEX equipment in a situation where ATEX would normally apply. This is overcome in stationary gas engines by creating conditions where a gas leak is managed so they do not arise in a dangerous condition. Otherwise issues such as pressure, temperature and electrical interference are likely to be comparable within the two industries.

5 Commercialisation

The key issue with this study, other than meeting the required safety and performance criteria is whether the developed system will be more affordable.

With satisfactory testing and performance validation completed during the demonstration phase, commercialisation may take place. Furthermore the following list will be achieved which will enable system costs to be determined and used for commercialisation purposes:

Design freeze allows a final bill of materials and product scope to be arrived at.

Costing of components, assembly and testing arrives at commercial sales value.

Development of service parameters and cost of ownership


Production of a commercial offer with Capex and Opex detail. Work with existing manufacturers of grid entry units to promote awareness

and benefits for this system.

5.1 IP

The idea of blending one or more gases together has long been carried out, the only novel approach here is transfer technology and using appropriate components from other industries in a way that hitherto has not been recognised. This is common practice in industry where low cost durable components are often used in place of more high value components i.e. aircraft overhead lockers using car door locks. There would be a clear advantage in relation to the market but it is unlikely that this can be protected by patent.

5.2 Commercialisation plans

To ensure that the maximum price reduction benefit is fully realised the proposed low cost propane blending system needs to be integrated within the grid entry unit while utilising the incorporated PLC control system. If produced as a standalone device the associated components, housing, some connections and the PLC costs need to be bought back in so the overall costs savings will be much less.

We believe that if this system is integrated within the Grid Entry Unit (which measures gas quality and energy flow) then this offers the best route to market as there are a smaller number of suppliers of this plant and all manufacture in UK.

To summarise:

Table 2: Propane blending system costs

Propane blending system CostA repeat low cost propane system integrated within grid entry unit plant expected cost

£18,784

A repeat low cost propane system stand-alone expected cost £59,784Current stand-alone propane blending plant £116,00

0

Refer to Appendix 8 for full cost table.

We believe that there are a number of options to take this forward:

Fully developed and financed model by CSL and demonstration partner (TBC) to create a product to offer to the manufacturers of the Grid Entry Unit such as Elster - this is the recommended option

Offer the concept to propane gas and equipment suppliers who are either already in the market or wish to become involved with no additional input from CSL.

Offer the concept to biogas/biomethane plant manufacturers or biogas plant system integrators who wish to add a propane blending system to their product range.

The best chance for an idea to take hold and be adopted is to create a demonstration unit with quantifiable performance results that one can offer to


proposed manufacturers. CSL has had initial discussions with Elster and they are interested in taking this forward.

5.3 Manufacturing plans

Future manufacturing is likely to be carried out by the development partner (TBC). They will either manufacture in house or utilise their own sub-contractors. How they achieve this is dependent on their business model.

6 Conclusion

Based on the work completed during the feasibility phase the development of a low cost Automotive (and industrial engine) component based propane blending system for CV enhancement of biomethane is practical. Furthermore it offers a significant potential for cost reduction, subject to overcoming the following constraints.

Use of non ATEX components in a location where ATEX components would normally be used is allowable assuming gas engine practices are acceptable.

Use for biomethane injection into Medium Pressure grid systems (maximum of 2 Bar).

7 Phase 2 Demonstrations

7.1 Objectives

Construction, test and validation of a commercially viable and technologically acceptable propane blending system for biomethane to grid systems based on low cost volume production automotive and industrial engine based components.

Demonstrate substantially reduced system Capex and Opex compared with existing systems.

Successfully integrate the control system into an existing biogas upgrading plant PLC to reduce the number of control systems in the overall plant.

7.2 Methodology

7.2.1 Summary of activity

Project start up review with project partners to agree task share and responsibilities. CSL to chair and manage the overall project.

Agree with the partners and project sponsors the scope of the design and the objectives.

CSL to create the basis of the design and ensure it is agreeable to all partners.

Detail design shared between partners, review of details, project costs and timescales.

Agreement to freeze design and proceed to procurement for components and build.

Agreement on build and test location(s), test method, test apparatus and consumables.


Construct demonstration system, including all hardware (gas system and pipework), electrical controls and software required for integrating the system into the host site.

Carry out test work and data collection. All development partners. We have allowed for one major iteration in the system to cater for the possibility of a component or design feature not to perform as expected. The failure cause will be identified and replacement justified.

Completion of the test work will enable a design freeze to be created, this can be used to produce a full cost repeat system or systems for commercialisation.

7.2.2 Project Milestones1. Confirmation and clarity on who the project partners are, the project

deliverables and production of the basis of design.2. Detail design, timescales, and detailed project costs.3. Creation of the demonstration system4. System test and data collection. Allow for 1 major iteration and re-test.5. Publication of results and design freeze.6. Final report and project completion.

7.3 Stakeholders

CNG Services, project lead and co-ordinator.

Control system, demonstration phase 2 onlyControl Systems Services LtdUnit 4 Lakeside Park LlantarnamCwmbranNP44 3XST: +44 (0)1633 868168D: +44 (0)1633 486322W: www.controlsystems.co.uk

Gas train components and facility for testing, future partner for production.Elster Instromet LtdMutual HouseLeicester RoadMelton MowbrayLeicestershireLE13 0DBT: +44 1664 504186W: www.elster-instromet.co.uk

7.4 Project Timescale

This provides an indication as to how long the project would take and the essential steps taken.


http://www.controlsystems.co.uk/

Phase 2 revised time plan. Week No1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Project kick-off with build and test partners, Review of design conceptAgreement on project aims and objectivesOutline build schemeOutline bench test schemeOutline field test schemeProduce basis for design and agree with partnersDetail design for systemDetail design for test systemSystem procurement and assemblyTest rig procurement and assemblySystem bench testDesign and test iterationField testDesign freezeProject completion

Figure 4: Project timescale


7.5 Economics

7.5.1 Project costs

The table below provides an indication of likely costs to build and develop a system to achieve a design specification that would be marketable.

Table 3: Project costs

Total projected project costDated 4th June 2013

BOM. Prime system componentsBiomethane Propane blending system demonstration model6% vol/vol propane/biomethane ratio, single unit biomethane capacity 300 Sm3/hrSystem pressure 2 BarRefer to PID dated 20/05/2013

Gaseous delivery system, flow control valve

Item Quantity Descriptionpart number

on PID supplier price cost1 1 Hydrostatic relief valve 16 Bar PRD Impco 30 302 1 Manual valve, 6mm SS BSS 20 203 2 LPG filter F1 BRC 30 604 1 LPG liquid solenoid SV1 Impco/GFI 60 605 2 pressure sensor PS1, PS2 GM/Bosch 60 1206 1 LPG vaporiser/regulator GP2 Impco 300 3007 1 Flow control valve FC1 Woodward 400 4008 2 temperature sensor T1, T2 GM/Bosch 60 1209 1 Flow meter, gaseous M1 Sierra 3000 3000

10 1 Non return valve NRV Impco 30 3011 1 Biomethane/propane mixer unit MIXER Woodward 400 40012 1 Manual valve, 25mm SS BSS 40 4013 1 water temperature regulator valve FC2 Amot 150 150

1 Water pump P1 Grundfoss 150 1501 Water pump (part of het recovery system) P2 (prototype only) 150 1501 HX Part of heat recovery system HX1 (prototype only) 300 300

14 1 Pipework, brackets, fixtures and fittings As required 500 500Target repeatable system cost Total 5270System production assembly time 40 hours 50/hour 2000Assemblers margin 33% 2514Target repeatable system selling price 9784Prototype Contingency, allow for 3 x system design iteration (excluding flow meter) 300% 6810

Total 12080

The following components are required to set up the demonstration system

Item Quantity Description part number supplier price cost1 Bespoke, one time control system Control Systems Ltd 19,000 190001 Programming Control Systems Ltd 5,000 50001 Wire loom, bespoke 600 6001 Other materials, pipes, frames, connections etc Various 2000 20001 250 HP regulator for methane storage, 10 Bar outlet Impco 300 3001 2nd and 3rd stage pressure regulator for test rig, 2 to 7 Bar outlet Impco 300 3002 Gas analyser take off lines BSS 100 2001 Pressure maintaining valve Dungs 350 3501 Installation hardware Various 5000 5000

Total 32750Contingency 20% 6550

39300

materials total 51380

Test and evaluation components, prices for component hireItem Quantity Description part number supplier price cost

1 Calorimiter 40002 Refrigeration container 20003 Chiller unit 20004 Heating system 10005 Data acquisition and control system 60006 Flare 10007 Non reuseable components 20008 Consumables (gas) 2000

total 20000Contingency 20% 4000

total 24000

Sub Contractor cost estimatesItem Quantity Description rate price cost

1 40 System assembly 50 20002 80 Test apparatus assembly 50 40003 6 Space rental and overheads 400 24004 240 Support labour 50 120005 1 Consumables 1000 1000

total 21400Contingency 20% 4280

total 25680

Total project costs 101060


7.5.2 Financing

It is proposed that costs incurred are submitted on a monthly basis and will include the following:

Project hours logged on “Project Minder” an on-line based project tracking system, with a brief explanation of tasks undertaken

Expenses incurred identified on the same system Materials and consumables purchased identified and logged. Project tracking chart for time, expenses and materials incurred against

projected amounts.

Project costs would be shared between CSL and Elster Instroment Ltd. All materials and labour required would be booked to this project and shared 50/50 (50 % between the partners (25% each) and 50% WRAP Grant aid.

Summary:

Table 4: Project cost sharing

Total project cost £101,060CSL £25,265Elster Instrument Ltd £25,265WRAP £50,530Balance £0

Future business return on investment would be recovered as follows:- (subject to an agreement between parties prior to Phase 2 start-up)

CSL, Approx £25,000 recovered through a licencing fee over the first 20 installations, reducing to 2.5% of the future system cost

Elster Instroment Ltd, investment recovery in future unit sales after payment to CSL of the licencing fee.

7.6 Evaluation and monitoring

Evaluation and monitoring would be achieved during the laboratory testing (see section 2.6). During the on-site demonstration a number of real time parameters will also be monitored including, but not limited to gas quality, pressure, composition, wobble index and flow rates.

7.7 HSE

To ensure system safety both in testing and to set future guidelines for manufacturing this low cost propane blending system would be subjected to the following studies as a minimum:

The proposed system shown in Appendix 4 will be subjected to a detailed HAZOP, a Hazard And Operability Study to assess system safety.

The installation, enclosure and operating environment will be subjected to a DSEAR (The Dangerous Substances and Explosive Atmospheres Regulations 2002)


Appendix 1 Calculations

The following calculations consider the performance using typical automotive pressure regulators and assess whether they would operate in a blending system, how much propane flow they would allow and therefore what grid capacity and pressure this system would usefully work with.

Review potential for 4 x Impco PEV LPG regulator/vaporiser units operating in parallel.

Each regulator able to vaporise and flow approx. 500kW of propane. Total flow from 4 x units is 2000kW Environmental conditions, -5 deg C to + 40 deg C (allows for solar gain) Propane is given as:-2

Density 582kg/m3 (liquid) Energy 92 Mj/m3 (vapour)3

Liquid/gas ratio 1:311 Energy for vaporisation 425 Mj/kg Specific heat 0.075 kj/mol k (1.7008 kj/kg k) (1 Bar 25 C constant

pressure) Density 1.87 kg/m3

Mol wt 44.096 g/mol Boiling point -42.1 C

Vapour pressure curve – see Appendix 1 Typical commercial propane specification from a UK refinery – see

Appendix 3 Calculations:

Energy to raise liquid propane under coldest conditions at maximum flow rate.

2000kW propane flow x 3.6 / 92 = 78.3 m3 gas 78.3/311 = 0.25 m3 of liquid 0.25 x 582/60/60 = 17kW energy to vaporise

Energy to raise liquid from – 5 to + 20 deg C

0.25 x 582/60/60 x 1.7008 x (-5 to +20) = 1.718 kW

Energy to raise gaseous propane from boiling point to + 20 C

0.25 x 582/60/60 x 1.7008 x (-42.1 to +20) = 4.268 kW

Total heat = 17 + 1.718 + 4.268 = 22.99 kW (5.74kW per regulator) Water flow to deliver required heat (assume from a waste heat source)

22.99 = flow x 4.187 x (70 feed temp – 60 exit temp) = 0.54 kg/sec 0.54 x 60 = 32.4 kg/min or approx. 32 L/min

2 http://encyclopedia.airliquide.com/encyclopedia.asp

3 This value is typical, value varies on actual “propane” composition


http://encyclopedia.airliquide.com/encyclopedia.asp

Assuming a 6:1 volume ratio 15:1 energy ratio how much biomethane can be processed?

Propane flow 78.3 m3/hr. 78.3 x 100/6 = 1305 m3

Energy 78.3 m3/hr x 92 = 7203.6 MJ x 100/15 = 48024 MJ Typical biomethane energy content is 36 MJ/m3 = 48024/36 = 1334

m3

Indicated flow 1300 to 1340 Sm3/hr This is significantly higher flow than one would consider for a low

cost approach so a lower flow of some 500 m3/hr is probably a more appropriate threshold.

Energy to heat the LPG tank.

Typical 2 tonne LPG tank is 1.2 m dia. And 4.7 m long containing some 4000L of propane.

Surface area is 18 m2. When full (80% only, a tank requires a minimum of 20% head space) so the surface in contact with propane will be less but for estimation we will assume the full surface are and the full load of 4000L.

There is no insulation in the tank walls so heat loss with a temperature difference of +8 to -5 is 13 C. Thermal conductivity is estimated at 43 W/m2k so 43 x 18 x 13 = 10062W or 10kW/2 tonnes storage capacity.

A system blending 500 m3/hr of biomethane will require 500 x 24 x 365 x 95/100 (operational time) x 6/100 = 249,660 m3 of propane gas a year. A 14 day storage requires 249,660 x 14 /365 = 9576 m3 of gas or / 311 (liquid/gas ratio) = 30.8 m3 of propane. Say 30,000 L at 4000 L per tank is 7.5 tanks. (make it 8 tanks) This requires 8 x 10 = 80 kW to heat.

This heat can be delivered by water as cold as 20 deg C so may be readily available on site, alternatively the tanks can be partially buried so significantly reduce heat demand and one also has to consider how much of the year is the ambient below 8 deg C and judge whether a simple heating system is more dependable than using a propane liquid pump, being the alternative.


Appendix 2

The following is a summary of how automotive LPG components operate.

A typical automotive pressure regulator unit is equipped with a liquid inlet valve to admit propane into a heated chamber, when propane is heated it boils off and pressure rapidly increases, if gas is not drawn off the pressure builds in the this primary chamber and closes the inlet valve to prevent more liquid being introduced.

A secondary pressure control system takes gaseous propane from the primary circuit and maintains pressure at the outlet (provided the drawn off propane does not exceed the ability of the system to deliver).

Regulators are equipped with a reference port so that the actual outlet pressure of the gas is relative to that port and can be set within a range above the reference pressure so that gas will always flow out as long as there is a demand.

Automotive pressure regulators are designed to operate with great accuracy in a highly transient environment to meet highway emission regulations; this application relies on good stability so the automotive product should readily meet the demands for flow and consistency.

Differing gasses blend better when done so at similar temperatures, the heating circuit built into the regulator uses water to transfer energy, the flow of water may be regulated for temperature and flow so that sufficient energy is transferred not only to vaporise the propane but also heat the propane gas to the same temperature as the biomethane.

Propane gas exiting the pressure control and heating system may then be regulated for flow using one of the many flow control valves used in the automotive industry, these may be electronic throttle bodies used in the so called drive-by-wire systems prevalent in most modern vehicles.

The final main component is to mix or blend the propane and biomethane together in a homogeneous mixture. A typical automotive venturi mixing device may be used, this is designed to do this task and may often be found in stationary CHP units, particularly those that need to meet stringent emission regulations.

A2.1 Component evaluation

Components used in the gas train must be capable of withstanding expected system pressures with a reserve factor.

All components used in the liquid propane circuit in an automotive environment are rated and likely to well exceed the temperatures and pressures expected. Automotive under hood components are normally rated for -40 to + 120°C, industrial applications are more likely to only meet -20 to + 80 C.

Pressures seen downstream of the vaporiser in an automotive application are generally only rated to meet the needs of turbocharged or supercharged engines where boost pressures up to 2 Bar can be expected. This may be the limiting factor in component selection or what gas grid pressure such a system may be connected to. LP and MP.


Electrical and electronic components are typically rated for 12 or 24 V DC operation and are engineered for considerable shock protection and EMI/RFI emissions and sensitivity. The likely issue is the ability to adapt such systems to industrial interface and communications protocols so they may be interrogated and controlled by standard host systems.


Appendix 3 Properties of propane


Appendix 4 P&ID gaseous phase propane blending system


Appendix 5 Propane blending system control description.

The following describes how a propane blending system operates. Refer to the PID in Appendix 4. The system labels SVI, PRV1 etc refer to items on the diagram.

Table 5: List of devices to measure and control

Device Description Type Range Comments

T1Measures the temperature of

the bulk propane to understand how much heat

is requiredPT100 30

T2Measures the temperature of

the propane gas, this is controlled to maintain gas

densityPT100 0 +20

T3Measures the temperature of the blended biomethane and propane to ensure it is within

specificationPT100 0 +20

PS1Propane vapour pressure, detects whether supply pressure is adequate

switch 4 to 20 Bar

PS2Propane gas pressure, detects whether supply pressure is as required

sensor 1 to 3 Bar

SV1Valve opens to allow

propane liquid to pass to the vaporiser

solenoid 12V DC

SV2Valve opens to allow heating water to pass to the propane

tanksolenoid 12V

DC

FC1, input

A control signal telling the control valve to move to a position allowing a given amount of propane gas to

pass

Woodward L series

0.5 to 4.5V

10 – 32V DC power

feed

FC1, output (position)

A position signal to confirm that the control valve has moved to the position as

instructed

Woodward L series

0.75 to

4.25V

M1Propane flow meter,

measures the propane gas flow

FCI ST75 series

4 – 20mA

P1Pump to deliver heating

water to the propane vaporiser

Water pump

230V 0.25k

W max

P2Pump to deliver heating

water to the propane storage tank

Water pump

230V 0.5kW max

FC2 Valve that controls the amount of heat energy

Flow control

4 – 20mA


passing to the propane vaporiser valve

Analyser 1Biomethane gas analyser, determines the methane

content from which the CV can be calculated

4 – 20mA

Analyser 2Gas analyser determines the

methane content (with propane) of the mixed

gasses

4 – 20mA

Fan. ATEXAir fan to purge air through the system enclosure, any

gas leaks will be flushed outEnclosure

vent 230V

Gas detectors

Detects the presence of gas under the lower explosion

limit allowing isolation of all gas circuits in the event of a

leak within the cabinet.

C3H8Allow for 2 units.

A5.1 OverviewBiomethane from a renewable source when transmitted into the gas grid is required to meet a set gas CV and Wobbe. This is achieved by blending in a quantity of propane (6% by volume, 15% by energy) into the gas stream.

A5.2 Propane blending

Liquid propane is supplied from a storage vessel to a shut off solenoid SV1, the presence of liquid detected in a pressure switch PS1. PS1 indicates to control that propane is present and enables the system, no propane flags a warning.Propane CV setpoint is entered remotely (the actual CV may change from bulk delivery to delivery).

Biomethane flowing from the upgrade system is analysed in analyser 1. The gas CV is transmitted to control.

A gas CV desired setpoint is entered remotely.

The result from analyser 1 is compared to CV setpoint, the offset is the quantity of propane required.

With SV1 open, liquid propane flows through PVR1 to P2, is vaporised to gas, flows through PVR2 to FC1.

Propane gas temperature and pressure is monitored by T2 and PS2, these are used to infer mass flow rate in conjunction with M a volumetric flow meter.

The required volume of propane calculated from propane CV, biomethane CV and setpoint CV is adjusted by FC1. Propane gas flows to the mixer where it is blended with biomethane.The blended gas is analysed by analyser 2, the result is compared with gas CV set point.


Any deviation is advised to control to vary the setting of FC1. The stability and accuracy of the system is required to maintain +/- 0.1 MJ in an average gas CV of 39.5 MJ.

An additional temperature sensor T3 detects gas temperature deviation and may be used for propane flow correction.

A5.3 Temperature control and vaporisationFor propane liquid to flow from the bulk storage requires the vapour pressure in the tank to be greater than the delivery pressure in the mixer, allowing for gas pressure reduction stages in the circuit. To achieve this a level of tank heating is necessary, the provisional concept is shown.

Waste heat is collected in HX1 and pumped in a circuit by P2.Liquid propane temperature is detected by T1, if calling for heat SV2 opens introducing heat into HX2.

P2 is a propane liquid vaporiser; the quantity of heat required is proportional to liquid flow. Pump P1 and flow control valve FC2 maintain gas temperature measured by T2. PS2 in addition to providing system pressure for mass flow calculation also monitors for system over/under pressure.A5.4 Pressure control

Pressure in the gas grid at P5 depending on the prevailing pressure will be set anywhere between 1 and 6.9 Bar. Case 1, assume 1 Bar grid pressure.

P5 pressure 1 Bar. P4 pressure nominally 0.5 Bar less at 0.5 Bar to allow PRV3 and 4

to control exit pressure. Pressure required at P3 may be set at above P4, say + 2 mBar. So

5.2 mBar to ensure propane is injected into the mixer, rate of flow controlled by V1

P2 will be controlled at 20 mBar above that of P3 by PRV2 P1 will be at the tank vapour pressure and P2 controlled by PRV1. The reference pressure for PRV1 and PRV2 is P3 The entire system pressure is set by PMV, a pressure maintaining

valve. As long as the tank vapour pressure is above P4 then propane will

flow through the system. Case 2, assume 6.9 Bar grid pressure.

P5 6.9 Bar P4 6.4 Bar P3 6.42 Bar, this will automatically reset if pressure at P5 is raised,

the only adjustment necessary being the pressure difference P3 to PRV2 reference.

P2 6.62 Bar P1 must be > P2 for propane to flow requiring a storage temperature

of > 7°C.


A5.5 Temperature control

Control of bulk liquid temperature to maintain propane vapour pressure. Water, preferably from a source normally rejected (compressor cooling

circuit or CHP system) can be circulated to a heating coil fitted into the base of the propane tank, this may be skin mounted or internal. The temperature of the propane should be monitored and a flow control valve in the water circuit operated to maintain propane temperature. This will maintain propane vapour pressure within a desirable range. See calculations for heat requirement.

Control of propane vapour temperature. The propane vaporiser requires heat delivered to boil off the propane,

this boils at -42°C so any water source above this temperature will allow heat transfer to maintain propane boiling. For practical purposes, water from a CHP or compressor cooling system may be utilised, typically in the 50 to 80°C range.

Water delivered from a primary source enters a 3 port valve into a secondary water pump designed to allow circulation around the vaporiser circuit, this blending circuit will allow careful temperature control of the propane vapour measured at T2. See calculations for heat requirement.

A5.6 Functional control Enable system. Is PS1 closed? If not warm up time required to increase VP of the propane.

Operate P2 circuit. Is biomethane flowing? If yes open SV1 Measure biomethane CV Look up CV setpoint Note error, open or close FCV Flow Control Valve till biomethane CV =

setpoint. Allow 15 minutes for system to stabilise. P1 heating circuit needs to

stabilise propane temperature at T2. Allow fluctuation within +/- 0.1 MJ of setpoint


Appendix 6 References

A list of reference documents are provided below, these should be considered in the propane blending system design.

A6.1 Part 1 - Gas industry

The following references to Legislation, Codes, Standards and Specifications are applicable, the latest editions, addenda, amendments and supplements shall be used. Related Codes, standards, and specifications referred to in the following documents are also applicable.

A6.1.1Legislation

Pressure Systems Safety Regulations 2000

Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002

Electricity at Work Act 1989

Construction Design and Management Regulations 2007

Pipeline Safety Regulations 1996

Pressure Safety Systems Regulations 2000

Gas Safety (Management) Regulations 1996

Gas Safety (Installation and Use) Regulations 1998

Management of Health and Safety at Work Regulations 1999

Pressure Equipment Regulations 1999

Town and Country Planning Act 1990

A6.1.2Gas distribution network specificationsX/SP/P/10 Specification for general pipelining designed to operate at

pressures greater than 7 bar (Complementary to BS8010)

X/SP/P/2 Specification For Welding Of Land Pipelines And InstallationsDesigned To Operate At Pressures Greater Than 7Bar(Supplementary To BS 4515‐1:2009)

X/SP/P/5 Specification for the welding and inspection of Austenitic SteelPipework

X/SP/P/8 Specification for the welding of steel onshore natural gasinstallations designed to operate at pressures greater than 7 Bar.

X/SP/NDT/2 Specification for Non‐Destructive Testing of Welded Joints in SteelPipelines and Pipework


X/SP/WP/1 Specification For Weldability Testing Of Pipe Fittings For Service AtPressures Above 7 Bar

X/PM/PT/1 Management Procedure For Pressure Testing Pipework, Pipelines,Small Bore Pipework And Above Ground Austenitic Stainless SteelPipework

X/PM/TR/30 Management Procedure for Commissioning And DecommissioningOf Above 7 Bar Pipelines and AGI's

X/SP/CW/6 Specification for The External Protection Of Steel Line Pipe AndFittings Using Fusion Bonded Powder and Other Coating SystemsPart 1 ‐ Requirements For Coating Materials And Methods Of Test

X/SP/PA/10 Specification for new and maintenance painting at works and sitefor above ground pipeline and plant installations

X/PL/ECP/1 Policy for Corrosion Control Of Buried Steel Systems

X/PM/ECP/2 Management Procedure for Cathodic Protection of Buried SteelSystems

X/SP/TR/18 Specification for Engineering of Pipelines and InstallationsOperating at above 7 Barg

X/SP/TR/25 Specification for the Construction of Pipelines and InstallationOperating at above 7bar

X/PM/TR/28 Management Procedure for the siting and installation of markerposts for pipelines operating above 7 bar

X/SP/TR/29 Specification For Marker Posts To Be Used For Above 7 Bar(g)Pipelines

X/SP/CE/1 The Design, Construction and testing of Civil and Structural works

X/SP/PW/11 Specification For Pipework Systems Operating At PressuresExceeding 7 Bar: Part 2 ‐ Fabrication, Construction And Installation.

X/SP/SSW/22Specification For Safe Working In The Vicinity Of National Grid High Pressure Gas Pipelines And Associated Installations ‐ Requirement

X/SP/HAZ9 The Application of Formal Process Safety Assessments During Engineering Design Phases

A6.1.3British Standards

BS 1722 Specification for fences: Part 12 - Steel palisade fences

BS 7430 Code of practice for earthing.

BS 476 Fire Tests on GRP Buildings (load tests)Part 21

BS 5467 Specification for Low Voltage Cables (upto 1000 volts)

BS7835 Specification for Medium Voltage Cables (11,000) volts)


BSEN 206-1 Concrete. Specification, performance, production and conformity2000

BS 8500: Concrete. Complementary British Standard to BS EN 206-1. Method of 2002 specifying and guidance for the specifier

A6.1.4European standards

ATEX 137 (118a) Directives on Safety on InstallationATEX 95a (100a) Directive on Safety of ApparatusATEX 94/9/EC Equipment for use in potentially explosive atmospheres

A6.1.5Institution of gas engineers and managers publications

IGEM/TD/1 Steel Pipelines and associated installations for high pressure gas transmissionEdition 5

IGEM/TD/1 Handling storage and transport of steel pipe, bends and fittings Edition 5Supplement 1

IGE/TD/12 Pipework Stress Analysis for gas industry plantEdition 2

IGEM/SR/15 Integrity of safety-related systems in the gas industryEdition 5

IGEM/ SR/22 Purging Operations for Fuel Gases in Transmission, Distribution and Storage

IGE/SR/23 Venting of Natural Gas

IGE/SR/25 Hazardous area classification of Natural Gas installationsEdition 2

IGEM/GM/ 5 Selection, installation and use of electronic gas meter volume conversion Edition 3 systems.

IGEM/GM/7A Electrical connections for gas metering equipment

IGEM /GM/7B Hazardous area classification for gas metering equipment

IGEM /GM/8 Non-domestic meter installations. Flow rate exceeding 6 m3h-1 and inlet pressure not

Part 1 exceeding 38 bar.


Part 2 exceeding 38 bar. Part 2: Locations, housings and compounds.



Parts 3 exceeding 38 bar. Part 3: Fabrication, installation, testing and commissioning

IGEM/GM/8 Non-domestic meter installations Flow rate exceeding 6 m3h-1 and inlet pressure notPart 5 exceeding 38 bar Part 5: Notices and labels

IGE/GL/2 Planning of transmission and storage systems operating at pressures exceeding 16 Edition 2 bar

IGE/GL/5 Procedures for managing new works, modifications and repairsEdition 2

A6.2 Part 2 - Automotive, industrial engineA6.2.1Legislation

SI2008. Statutory instrument

A6.2.2EnvironmentEMC EN61000-6-2 Immunity to industrial EnvironmentsEMC EN61000-6-4 Emissions for industrial ImmunitySAE J1113-21 Radiated ImmunitySAE J1113-11 Conducted Transient Immunity

A6.2.3European standardsR110R115R67EMC Directive 89/336/EECMachinery directive 98/37/ECCE

A6.2.4International standardsISO 15500RS232C


Appendix 7 Typical automotive LPG components

The following components have been reviewed and are potentially suitable for use in the propane blending system. The range of components available is extensive being produced in high volumes in most areas of the world, in particular, Europe, North America, Brazil, Argentina, India and China. Choice should be based on performance and availability of full technical data from which informed decisions may be made.

1. Automotive LPG vaporiser/regulator systems are designed to deliver controlled levels of LPG vapour from a liquid source at a consistent outlet pressure. Some are equipped with pressure and temperature sensing so that LPG vapour may delivered at a controlled temperature and pressure to the mixing device or injection system.


2. Automotive gaseous fuel injectors have been developed to provide reliable fuel metering with good durability in harsh environments far in excess of anything seen in the static gas industry.


Gas flow valves. The Woodward L series is used for fuel control in gas engines and CHP and one of the major global manufacturers of such components.


3. Automotive and industrial engine air fuel ratio control systems are designed to give accurate blending and homogeneous mixing of fuel and air, the principals may be applied to the mixing of two known gasses. The addition of condition sensing coupled with loop control improves accuracy.


Appendix 8 Product costs for commercialisation

The following table provides more detail on the price make up for the commercialisation options.

Refer to Table 2: Propane blending system costsCommercialisation product installed cost estimates

Low cost propane blending system integrated within a biogas upgrade plant when compared with an existing system

Product descriptionTypical 100kg/hr

systemProposed low cost

system. CommentsLPG storage, rental, delivery charge only 0 0 not included, same for any system

Installation. Electrical connections, pumps 30,000 5,000

No requirement, if tanks buried, average UK ground temp 6 deg C will deliver propane vapour pressure of 6 Bar

Pipework 7,000 2,000This is probably excessive, pipe need only be 6 to 8 mm diameter for design flow rate of 60L/hour

LPG control and blending system 35,000 9,784 Carried over from Phase 2 cost tablePLC control system 30,000 1,000 Allowance for integration componentsInstallation and commissioning 8,000 1,000 part of upgrade plant, allowance for testingSystem overview and management 6,000 5,000 One time cost per system integrator

116,000 23,784System cost + propane storage installation (generally hired or part of the supply contract)

18,784 Possible repeat cost for system integrator

Low cost propane blending system built as a stand alone device along the lines of an existing system

Product descriptionTypical 100kg/hr

systemProposed low cost

system. CommentsLPG storage, rental, delivery charge only 0 0 not included, same for any system

Installation. Electrical connections, pumps 30,000 5,000

No requirement, if tanks buried, average UK ground temp 6 deg C will deliver propane vapour pressure of 6 Bar

Pipework 7,000 7,000LPG control and blending system 35,000 9,784PLC control system 30,000 30,000Installation and commissioning 8,000 8,000System overview and management 6,000 6,000

116,000 65,784System cost + propane storage installation (generally hired or part of the supply contract)

59,784 Possible repeat cost for system integrator


technical report templates - wrap report.docx · web viewfinal report : propane blending system...

Documents