Biogas as a road transport fuel

Biogas as a road transport fuel

Introduction

Biogas is produced from the process of anaerobic digestion (AD) of wet organic waste, such as cattle and pig slurries, food wastes and grown wet biomass. The AD process produces CO2, methane and a digestate that can be used as fertiliser. The methane (biogas) can be burned to provide heat and/or electricity, or it can be used as a transport fuel in compressed form in the same way as compressed natural gas (CNG). This report examines the role that biogas can play as a transport fuel.

1.1 The Drivers for Biogas as a Transport Fuel

There is increasing interest in the use of biogas as a fuel for heat and electricity production, and as transport fuel. The key drivers behind this are:

The increasing regulation and taxes on waste disposal such as the landfill tax, the landfill allowance and trading scheme and the animal by-products regulations, which are forcing local authorities and the waste industry to look for new routes for treating organic waste;

An increasing need for renewable fuel sources to help reduce our carbon emissions and mitigate climate change and, supported by the climate change programme, the Renewables Obligation, as well as the EC’s Biofuels Directive and the proposed Renewable Transport Fuel Obligation (RTFO);

The recent report from the Government’s biomass task force, which is looking to promote greater use of biomass
in the UK;

Measures to improve local air quality and the need for clean transport fuels in urban areas.

The Government’s biomass task force, although focusing on heat and electricity, sees a role for biogas in transport and has as one of its recommendations that “the Government carries out an economic and environmental assessment of the potential for AD biogas to replace fossil diesel.” This report aims to go some way towards addressing this recommendation.

Similarly the recent proposals for an RTFO will be particularly important in the future development of biogas as a transport fuel. The current proposal for the obligation does not include biogas, but this is under review as part of the development of the full scheme.

1.2 Study Objectives and Methodology

The aim of this study was to explore the idea put forward by the Government’s biomass task force and others that there is a role for biogas in transport in the UK. As such it is perhaps the first time this issue has been studied at a broad policy level. In particular the study has attempted to address the following questions:

What is the theoretical and practical biogas resource available from the UK waste stream?
What technologies are available to produce biogas suitable for transport applications?
What are the technical and practical issues concerned with developing a biogas-powered vehicle fleet?
What is the current state of experience with transport biogas in the EU and UK?
What is a realistic scenario for transport biogas within the UK energy matrix?
What are the costs and environmental benefits of a biogas fleet in the UK?

To address these issues the study comprised two main elements:

1 A desk review – pulling together the major available information and reports on biogas and transport, covering the potential resource in the UK, production technology, production costs, vehicle and fleet issues and existing experience in the EU and UK.

2 A scenario analysis – the data from the desk review was used to carry out a cost analysis of producing biogas for transport use, and to estimate the environmental impacts/benefits on a “well-to-wheels” basis, consider potential uptake scenarios in the UK and discuss possible policy measures for supporting the development of a market for biogas as a transport fuel.

1.3 Structure of the Report

This report sets out the findings of this study. Section 2 sets out the resource that is available for producing biogas, together with the basic details of production technology and estimates the theoretical maximum amount of gas that could be produced in the UK. Section 3 then explores how this gas can be used in vehicles, describing the basic technology
requirements, and vehicle availability and fuel supply issues. The energy and emissions data on biogas as a transport fuel are set out in section 4 and the costs of producing and using the fuel are estimated in section 5. Section 6 reviews experience of developing and using biogas and gas vehicles in the UK and other countries, and the lessons learnt from this experience. Building on this experience, section 7 proposes two scenarios for the development of biogas as a transport fuel in the UK: a high scenario and a low scenario, and the environmental impacts of these two scenarios are estimated. This section also looks at the potentials to developing this market and how these barriers may be overcome. Finally, section 8 summarises the conclusions from the research and gives recommendations for taking the debate forward.

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