Anaerobic Digestion Evidence Availability and Gap Analysis · 2015-02-11 · Prof David Manning...

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Anaerobic Digestion Evidence Availability and Gap Analysis

A strategic review of research and available evidence on anaerobic digestion, with a prioritised assessment of gaps and recommendations for further work

Report to Defra

Project Number WR1311

April 2011

Paul Frith, Frith Resource Management Ltd

Dr Jane Gilbert, Eco Alternatives Ltd

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Executive Summary This report is a summary of a rapid overview of evidence on completed and on‐going research into anaerobic digestion of food and other waste e.g. paper, manures, crop residues and energy crops (however it was not limited to these feedstocks only). It has been conducted following the publication of Defra’s 2010 AD Framework Document, which sets the context for this study.

This report does not attempt to summarise all the available evidence on AD, as this would be an extremely large project. Instead it summarises key areas where evidence was found to be strong, partial or missing. Reference to select publications are made as part of an initial desk based data collation exercise, however, it is recognised that this is not intended to be comprehensive. Expert opinion from stakeholders, organisations and individuals has been sought to supplement the desk review.

In general, the evidence base was particularly strong in the following areas:

• Process optimisation and characterisation – there is a large body of scientific evidence, as well as a number of dedicated web sites detailing process control and biogas optimisation;

• Manure and energy crop digestion – these feedstocks are widely digested in the USA and Europe, hence they have been widely reported; and

• Small‐scale rural systems – which are aimed principally at developing countries, where operating standards may not meet UK legislative requirements (e.g. in respect of emissions).

In recent years, Defra, DECC and WRAP have commissioned research into a range of AD‐related areas, including:

• Emissions evaluations;

• Food waste digestion, including process optimisation;

• AD technologies and applications; and

• Benefits of digestate application to soils, including market development.

Some of this evidence has been published, whilst some research projects were ongoing at the time of writing. However, in order to realise Defra’s vision for AD as outlined in the 2010 Framework Document, this study identified areas where further evidence is required. This report thus presents a prioritised assessment of the gaps where evidence is still needed, identifying whether initiatives are required in the short‐ or longer‐term as well as indicating whether this work would be applied or requiring significant research innovation.

The evidence gaps identified within the analysis are categorised into 14 areas and summarised in Table 1. There are 23 specific actions that fall within these categories as defined within the report, and their respective importance is categorised as high, medium or low priority.

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Table 1 – Evidence gaps identified with priority rankings

Gap Topic Identified Priority of the particular actions to address these gaps*

1. Up‐to‐date, accurate information on the current size of the AD sector

Medium

2. Characterisation & Understanding of primarily food waste feedstocks and digestion

High

3. Municipal interfaces with AD treatment High 4. Financial: capital costs, operating costs and revenue High & Medium 5. Financing of Community Scale Projects High 6. Collating existing information on AD into usable formats on

specific topics gaps were observed High & Medium

7. Case study transferability High 8. Communication materials Medium 9. Stimulating the growth in AD technologies through

different business models High

10. Training needs Medium 11. Regulatory issues High 12. Applications of Digestate High & Medium 13. Biogas as Transport Fuel Medium 14. Evidence of functional contractual arrangements using on

farm digestion Low

*High = Cross‐cutting, addresses gaps in a number of work streams; generally UK‐specific; generally a short‐term intervention; may impede the development of AD in the UK if not acted on.

Medium = Addresses gaps in a few work streams; intervention may need to be carried out over a longer period of time than those ranked as High.

Low = Addresses gaps in only a small number of work streams; evidence gaps may be addressed by other parties in due course; Unlikely that failure to address the gap will impede the development of AD in the UK

This report is accompanied by an Excel spreadsheet with detail of the key areas of evidence reviewed.

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Acknowledgements The authors are grateful to the following individuals for their helpful suggestions and valuable insight during the course of this project.

Charlotte Morton ADBA

Philip Smith AEA Technology

Florian Amlinger Austrian Biogas Association

Jan Habart CZ Biocom (Czech biomass association)

Jan Liebtrau DBFZ, Germany

Lynn Raw Defra

Angie Ehringer Defra

David Sher Environmental Services Association

Claudia Amos Enzygo

Denise McGlynn EU Skills

Arthur Wellinger European Biogas Association / Task 37

Josef Barth European Compost Network

Michael Koettner IBBK, Germany

Wolfgang Mueller Innsbruck University, Austria

Prof Ed Stentiford Leeds University

Prof Andrew Wheatley Loughborough University

Prof Vince Smedley Loughborough University

Prof David Manning Newcastle University

Lucy Hopwood NNFCC

Hugh Bulson Organic Resource Agency

Prof Richard Stone Oxford University

Birgit Balkenhoff SLR

Prof Charles Banks Southampton University

Clare Lukehurst Task 37, IEA

David Tompkins WRAP

Nina Sweet WRAP

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Contents Executive Summary ................................................................................................................................. 2

Acknowledgements ................................................................................................................................. 4

1 Introduction .................................................................................................................................... 7

1.1 Background ............................................................................................................................. 7

1.2 Project objectives .................................................................................................................... 7

1.3 Project Scope .......................................................................................................................... 7

1.4 Approaches to Obtaining Evidence ......................................................................................... 8

2 Methodology ................................................................................................................................... 9

3 General observations .................................................................................................................... 12

4 Evidence identified........................................................................................................................ 13

4.1 Improving our understanding of the AD landscape .............................................................. 14

Summary ....................................................................................................................................... 15

Gaps .............................................................................................................................................. 15

Recommendations ........................................................................................................................ 15

4.2 Raising Awareness – Community AD and Localism .............................................................. 17

Summary ....................................................................................................................................... 18

Gaps .............................................................................................................................................. 18


4.3 Building Investor Confidence ................................................................................................ 19

Summary ....................................................................................................................................... 19

Gaps .............................................................................................................................................. 19


4.4 Building UK Skills ................................................................................................................... 21

Summary ....................................................................................................................................... 21

Gaps .............................................................................................................................................. 22


4.5 Smarter Regulation ............................................................................................................... 23

Summary ....................................................................................................................................... 23

Gaps .............................................................................................................................................. 24


4.6 Building Safe and Secure Markets for Digestate ................................................................... 25

Summary ....................................................................................................................................... 25

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Gaps .............................................................................................................................................. 26


4.7 Building Markets for Methane and Transport Fuels ............................................................. 27

Summary ....................................................................................................................................... 27

Gaps .............................................................................................................................................. 27


4.8 AD in the Rural Community .................................................................................................. 28

Summary ....................................................................................................................................... 28

Gaps .............................................................................................................................................. 29


5 Addressing the Gaps ..................................................................................................................... 30

6 Defra’s AD Strategy Research Work Stream ................................................................................. 36

Appendix 1 – The AD Landscape Evidence Base ................................................................................... 38

Appendix 2 – The Raising Awareness – Community AD and Localism Evidence Base ......................... 40

Appendix 3 – The Building Investor Confidence Evidence Base ........................................................... 43

Appendix 4 – The Building UK Skills Evidence Base .............................................................................. 43

Appendix 5 – The Smarter Regulation Evidence Base .......................................................................... 44

Appendix 6 – Safe and Secure Markets for Digestate Evidence Base ................................................... 46

Appendix 7 – The Building Markets for Methane and Transport Fuels Evidence Base ........................ 48

Appendix 8 – The AD in the Rural Community Evidence Base ............................................................. 49

Appendix 9 ‐ Glossary ........................................................................................................................... 50

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1 Introduction

1.1 Background A full review of Government waste policy is currently underway and is due to report in spring 2011. This will consider Anaerobic Digestion (AD), and other energy from waste technologies, as part of the Government’s overall approach to moving towards a zero‐waste economy. The development of a strategy for AD in the context of the waste hierarchy will feed into the work on the Waste Review. Areas of evidence to be covered include operation, technology, feedstock, nature and use of digestates, biogas use, economics, planning and legislation.

Part of the requirements for the review and strategy for anaerobic digestion is for a rapid overview of completed and on‐going research into anaerobic digestion as well as an assessment of areas where evidence is still lacking (i.e. in the form of a gap analysis).

This study was carried out in parallel with Defra’s anaerobic digestion strategy and the activities of its associated working groups.

1.2 Project objectives The following specific objectives have been addressed through this piece of work:

• a rapid overview of completed and on‐going research into anaerobic digestion of food and other waste e.g. paper, manures, crop residues and energy crops but is not limited to these feedstocks only; and

• a prioritised assessment of the gaps where evidence is still needed identifying whether initiatives are required in the short‐ or longer‐term as well as indicating whether this work would be applied or requiring significant research innovation.

This report does not attempt to summarise all the available evidence on AD, as this would be an extremely large project. The report summarises key areas where evidence is strong, partial or missing. Reference to select publications were made as part of a initial desk based data collation exercise, however it is recognised that this is not intended to be comprehensive.

1.3 Project Scope • The project will focus on the eight work themes of the AD Framework, addressed in sections

4.1 – 4.8 respectively, specifically:‐ o Improving our understanding of the AD landscape o Raising awareness of AD – community AD & localism o Building investor confidence o Building UK skills o Smarter regulation o Building safe and secure markets for digestate o Building markets for biomethane for transport fuels

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o AD in the rural community

• This report is intended to provide an overview of the current level of evidence (and gaps therein) relative to the work themes

• It is not intended to be an exhaustive study of the research, but to gather a general feel for evidence landscape that will inform the actions required to overcome any relevant barriers to AD development

• The work would exclude sewage sludge and waste water digestion, but make reference to the wealth of relevant information that may be derived from this sector for areas such as digester design, etc.

• The focus for the study is not on academic ‘technical’ aspects per se, as the detail here would necessitate an extremely wide ranging study (and associated analysis and report), but rather on the policy influencing aspects (including implementation issues and barriers) as outlined in the work themes and supporting subset of questions

We have assumed ‘evidence’ to mean investigations reported through research papers, case studies, technical reports or other material with independence or peer review. Evidence was categorised depending upon the source documentation, namely:

• Peer reviewed scientific research (journals)

• Reports

• Specialist web sites

• Toolkits

• Case studies

1.4 Approaches to Obtaining Evidence

The general approach taken to garner the available evidence is summarised below and explained in more detail in the following ‘Methodology’ section.

• Key stakeholders (e.g. researchers, industry bodies etc) were targeted and brief interviews (either by ‘phone or e‐mail) undertaken to gain an understanding of works completed, works ongoing or proposed, and knowledge gaps as regards the work themes in particular

• Searches of academic research and utilising other web ‐ based data sources to provide additional information on evidence availability and gaps

The evidence considered was prioritised as being pertinent to the UK, but with supporting EU (or other international) evidence or references, notably where gaps exist in UK knowledge or where a particular specialism is identified from other countries evidence / research.

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2 Methodology The following is a description of the methodology for delivery of this project.

• A format was agreed for the spreadsheet to be used by the Research Managing Agents (Jane Gilbert & Paul Frith, hereafter referred to as RMA) in order to record, collate and filter evidence for the project. This spreadsheet was also used to identify gaps.

• Utilising the Work Specification Document and industry knowledge, the RMA investigated relevant evidence (papers / projects / research summaries) through a desk based study, as shown in Figure 1, to ensure as comprehensive an initial dataset is gathered as practicable, within the project timescales.

• The evidence obtained was reviewed and recorded within the spreadsheet. Keywords were added where appropriate and all evidence was categorised as regards document type, date, country of origin, source, title, primary and secondary keywords and by each of the Defra work themes. The strength of evidence ranked as either:

o Comprehensive (C) –covers key aspects well o Moderate (M) – covers key aspects in moderate detail o Partial (P) – mixed evidence base, some aspects covered well others limited or with

gaps o Limited (L) – Poor evidence base o Blanks indicate no evidence was identified

• In addition, key stakeholder organisations and academic institutions were contacted and interviewed to garner views of the ‘experts’ and other industry / stakeholder bodies as regards Anaerobic Digestion evidence. These views were also used to inform identification of gaps and potential areas of further research. These are recorded in the accompanying Excel spreadsheet to this report.

• The desk based research and the interviews identify an evidence record which is the primary basis for the Gap Analysis and summary. The evidence is grouped by the relevant work theme and contained in the body of the report and supporting Appendices 1‐8.

• Where gaps in evidence have been identified, these have been highlighted and a comment made as to their nature and as regards prioritising the evidence needs in a Gap Analysis commentary. The gaps have been ranked, in the authors’ opinion, as being either High, Medium or Low based on the following criteria (Table 2):

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Table 2 – Recommendation ranking criteria

Rank Criteria

High • Cross‐cutting, addresses gaps in a number of work streams

• Generally a UK‐specific issue, that is unlikely to be addressed from international sources

• Generally a short‐term intervention

• Unless intervention takes place, the gap may impede the development of AD in the UK

Medium • Addresses gaps in a few work streams

• Intervention may need to be carried out over a longer period of time than those ranked as High

Low • Addresses gaps in only a small number of work streams

• Evidence gaps may be addressed by other parties in due course

• Unlikely that failure to address the gap will impede the development of AD in the UK

• A presentation based on initial findings was presented to the Defra Anaerobic Digestion Working Group 1 (3rd meeting) on the 24th February 2011.

• This report incorporates the project findings and supporting appendices. A separate searchable spreadsheet is also provided, including URLs for relevant research / evidence for further investigation.

The following schematic illustrates the process undertaken in the delivery of this project (Figure 1).

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Figure 1 Project Process Diagram

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3 General observations A significant body of evidence exists on feedstocks, process optimisation / characterisation, biogas yields, as well as case studies of operational systems and community AD models. The authors have attempted to identify and capture some of the key published evidence identified during this study; however, due to constraints of the project, reference to only a small selection of publications has been made.

Anaerobic digestion has long been the focus of academic study, and the peer reviewed literature contains a wealth of detailed technical information. There also exists a vast amount of ‘grey’ literature, of varying quality; some are excellent information sources, although some are poorly written and badly referenced.

There are a number of specialist interest groups promoting AD who make available detailed technical reports. These have been drawn on extensively in this gap analysis, as many provided useful summaries on specialist subjects. However, a note of caution needs to be sounded. Specialist interest groups, by definition, aim to promote specific points of view. Case studies, by nature, tend to focus on successful projects; hence information on projects that have failed tend to be overlooked, even though the associated cause and effects could provide useful insights for the developing AD sector in the UK. Little evidence about failed projects and the contributing reasons were identified during this study.

The evidence search was complicated by the inconsistent use of terms in the published literature. In some instances a number of terms were used to describe similar products or processes: the term “digestate” being the notable example, with at least seven variations noted. For consistency’s sake this report refers to Defra’s preferred terms, as defined in PAS 110 and the AD Quality Protocol.

As such a large body of evidence was identified during this study, government, industry and research bodies could benefit from co‐ordinating research findings. Existing portals e.g. the NNFCC’s Biogas Portal or WasteNet could usefully be updated to signpost researchers and industry to existing areas of expertise and evidence identified in this study.

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4 Evidence identified The evidence identified during this study could generally be clustered into the following three main areas:

• Process optimisation and characterisation – there is a large body of scientific evidence, as well as a number of dedicated web sites detailing process control and biogas optimisation;

• Manure and energy crop digestion – these feedstocks are widely digested in the USA and Europe, hence they have been widely reported; and

• Small‐scale rural systems – which are aimed principally at developing countries, where operating standards may not meet UK legislative requirements (e.g. in respect of emissions).

The eight work streams identified by Defra in its December 2010 Framework document1 have been used as subject areas to categorise the evidence identified. For simplification purposes, this has been set out in tables, with the evidence ranked as either: comprehensive, moderate, partial or limited.

A brief summary for each work stream is given, and the evidence gaps identified. More detailed analysis of each work stream is detailed in Appendices 1‐8.

1 Defra (2010) Developing an Anaerobic Digestion (AD) Framework Document

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4.1 Improving our understanding of the AD landscape DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• What is the size of the AD industry today?

• How much material do we have to put in digesters?

• Will there be enough waste derived feedstock to go round or will we need to grow increasing amounts of energy crops?

• Which models for AD development fit where in terms of location and feedstock?

• What are the real costs of AD?

Table 3 summarises the evidence base, according to this analysis, further supporting information is contained in Appendix 1 and in the accompanying spreadsheet file.

Table 3 – Evidence summary: Improving our understanding of the AD landscape

DEFRA Priority Areas

Peer reviewed scientific research (Journals)

Reports Specialist web sites

Toolkits Case

studies Comments

SIZE Number of plants, location, capacity etc.

P M L Evidence is time‐sensitive, ongoing mapping work underway

FEEDSTOCKS Types C C C C C

Emphasis on manures & energy crops Sparse info on food wastes

FEEDSTOCKS Quantities – how much & where

P P Evidence is time‐sensitive, some ongoing work

FEEDSTOCKS Modelling arisings in the future

L On‐going work by DEFRA

FINANCIAL Capital costs P P P P Some estimates provided,

but large variations

FINANCIAL Operating costs L M M P Info on biogas yields –

optimisation & feedstocks

FINANCIAL Revenue P P P

Dependent upon fiscal incentives available Info on biogas yields, some information on pan European incentives.

C = Comprehensive; M = Moderate; P = Partial; L = Limited; Blanks indicate no evidence was identified.

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Summary The AD landscape work stream evidence base can be divided into two main areas:

• Time sensitive data – including, the current and projected size of the sector, modelling of waste arisings, plus financial data; and

• Time insensitive data – relating to feedstock characterisation and biogas optimisation.

The evidence base on feedstock characterisation and process optimisation is significant (time insensitive data), whereas the evidence on UK‐specific time sensitive data are sparse and of varying degrees of quality.

There are a number of government departments, non‐governmental bodies and trade organisations promoting and researching AD, such as Defra, DECC, WRAP, NNFCC, ADBA and the REA, who all collate information on the AD Landscape to a varying degree.

Gaps The key gaps identified include:

• Up‐to‐date, accurate information on the current size of the AD sector – This is only partially met through the NNFCC’s online portal “Biogas Map” (which is reliant upon self‐completion by industry), and WRAP’s annual organics survey (which is an historic review). DECC’s RESTATS and REPD databases currently only cover renewable energy capacity, but exclude AD.

• Characterisation of food waste feedstocks and digestion – The UK appears to be in the vanguard (with the possible exception of Italy) in the digestion of food wastes, with significant Defra and WRAP‐funded research being carried out at Southampton University. Extensive modelling and process characterisation has been carried out on energy crops and manures, and this could usefully be extended to include food wastes, especially municipal sources derived from local authority kerbside collections.

• Financial: capital costs, operating costs and revenue – Although some evidence exists, there is a need for more detailed capital cost estimates to be made available, that could usefully be incorporated into existing financial models. These will need to be UK‐specific, and cover both small‐scale decentralised as well as larger centralised facilities.

• Municipal interfaces with AD treatment‐ the collection system for organic waste from households is well understood, however the implications for wet/dry systems and the respective seasonality implications are less well evidenced.

Recommendations • Investigate the feasibility of either: reviewing and updating the NNFCC’s Biogas Map on an

ongoing basis (to ensure site data are accurate) or; incorporating AD into DECC’s RESTATS and REPD databases;

• Incorporate results from ongoing research into biogas yields from food wastes into existing process models, as this will enable better estimations of likely revenue from AD plants to be made;

• Summarise key existing findings rather than ‘new’ research in areas such as: o Technologies available and appropriateness to different feedstocks; and

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o Quantifying, where possible, the wider benefits of AD (such as carbon benefits, job creation and community benefits etc.);

• Continue to investigate the long term implications of food waste only digestion to understand the process parameters, operating conditions and outputs from the process.

• Review and collate capital costs of AD plant components to improve the accuracy of financial model toolkits.

• Independent assessment of wet vs. dry AD systems, the best systems for different feedstocks and the interface with collection systems is an area that could merit investigation.

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4.2 Raising Awareness – Community AD and Localism DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How can we ensure that the benefits of using AD are understood and shared by everyone?

• Can we improve understanding of AD by all those involved in planning new facilities?

• Can we build on and work with community scale AD projects?

• Is there more that can or should be done to encourage the development of more smaller scale plants?

• How do we ensure that we continue to improve the technology that we are using and fill any knowledge gaps?


Table 4 – Evidence summary: Raising awareness – Community AD and localism




Toolkits Case

studies Comments

Disseminate information to inform public of the contexts in which AD can be used

M M

Wealth of information from abroad Little reference to financing options, as UK‐specific

Communications strategy ‐ case studies of good practice

C C C

A number of examples of case studies, mostly in Sweden, Germany & Austria

Facilitate joint working with community M M M

A number of examples of case studies, mostly in Sweden, Germany & Austria

Develop good case studies ‐ how to work within the existing planning requirements.

L L A few reports suggesting how operators could engage with community

Reduce the capital cost of small‐scale plant technology.

L L

Examples aimed at developing countries. This is also covered in the AD landscape work stream

Learn from experience of using AD elsewhere, especially science

C C C C Wealth of technical information, mostly in German and Swedish


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Summary The Raising Awareness work stream focuses on information and communication; however, there was significant cross‐over with issues in the Finance, Regulation and Rural AD work themes.

Information evidence through case studies and technical reports was strong, although the extent to which they would be transferrable to the UK context was unclear. Similarly, the scientific and technical evidence was particularly strong, both through peer reviewed scientific papers and technical web sites / reports. Technical scientific reports are often sourced from German literature, and the UK could benefit from translation into English.

Gaps The main gaps identified were:

• Case study transferability ‐ The case studies identified were mainly derived from Austrian and Swedish models. Some provided useful examples of the ways in which energy from AD could be used to benefit the local populace (e.g. through district heating systems). However, it was unclear what the “key success factors” were and whether they could be replicated directly in the UK bearing in mind the UK’s specific planning and environmental permitting requirements. In addition, there was little evidence illustrating the various financing options that could be explored by industry in partnership with local communities.

• Communication – Little evidence was found on the ways in which AD developers communicated with local residents. There was limited info as regards UK toolkits/ information identified.

• Reducing capital costs – There was little evidence identified as to how capital costs could be reduced for small‐scale systems. In Germany, quite a few on‐farm AD systems were self built by farmers, which could provide useful models for the UK. Some deregulation aspects identified by DEFRA research are relevant in terms of reducing capital requirements in European examples (e.g. around environmental controls)

Recommendations • A critical review of published case studies could be usefully carried out to identify the key

success factors and whether these could be transferrable to the UK. A simultaneous study to identify how and why other projects failed and the contributing reasons;

• Technical translation of scientific reports published in other languages, particularly German, into English;

• Improved information on financing options, including industry – community joint ventures;

• A review of self‐built AD systems in Germany and the ways in which this could be transferrable to the UK in order to reduce capital costs for small‐scale systems.

• There is a need for communications materials for AD local stakeholders to explain the role and impact of facilities. Models used in other industries, such as quarrying2, could be investigated and adapted accordingly.

2 See, for example the Sustainable Aggregates web site: http://www.sustainableaggregates.com/rprts_revs/rr_communication.htm [accessed on 5 April 2011], which contains a number of PDF documents aimed at communicating with local communities.

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4.3 Building Investor Confidence DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How do we work with banks and finance houses to reduce risks associated with projects and improve access to finance for projects of all scales?


Table 5 – Evidence summary: Building investor confidence




Toolkits Case

studies Comments

Work with banks and finance houses to reduce risks associated with projects and improve access to finance for projects of all scales

L

One key report highlighting problems experienced in Europe Ongoing government reviews of fiscal incentives for renewable energy production underway

Help industry develop financial models that can be used to reduce costs of obtaining debt and equity finance and reduce the financial risks associated with AD‐ particularly smaller scale projects.

L L

Process modelling toolkits and financial toolkits exist. Limited relevance of European case studies to UK context.


Summary The Building Investor Confidence work stream links with the AD Landscape and Raising Awareness work streams. This is a topic where little evidence was identified that would be directly applicable to the UK.

Gaps The key gaps identified relate to a lack of information / evidence on:

• Business‐community financial models (see previous)

• Standard contractual models (see 4.8)

• Capital costs, in particular, scaling issues and small scale systems (see previous)

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Recommendations In addition to the recommendations made in the other work stream sections, it is recommended that:

• A study be undertaken to review the working models contractual and economic for the successful development of AD in other countries (e.g. Germany, Austria and Sweden) and the effects these have had on the growth and development of AD over the past decade. This could build on other work undertaken (e.g. Defra research) and usefully provide a framework in which the developing AD sector in the UK could be assessed.

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4.4 Building UK Skills DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How do we enable a skilled and competent workforce that is equipped with the knowledge that it needs to run a safe business in an environmentally sound fashion?

Table 46summarises the evidence base, according to this analysis, further supporting information is contained in Appendix 4 and in the accompanying spreadsheet file.

Table 6 – Evidence summary: Building UK skills




Toolkits Case

studies Comments

Develop and promote industry led training L L

Few toolkits providing technical information, some related training and qualification developed through DEFRA new Technologies programme (VRQ,HLA)

Encourage an environment that minimises barriers to growing a competitive domestic AD manufacturing base

Unable to identify specific relevant evidence. Information on small‐scale DIY systems available for developing countries. This area is a focus of all work themes as a general concept


Summary This is a work stream where there is little direct evidence available, as it spans a range of industry sectors, with diverse skills, needs and training requirements. UK Skills is currently mapping occupations and identifying training / information needs, therefore until this body of evidence is available, it is difficult to assess whether the evidence is in existence to support this.

There is a large body of information and technical data available that could be utilised by operators; however, this in itself would not translate into a competent and skilled workforce. Training courses are routinely provided by a number of bodies, both in the UK and Europe.

With regard to manufacturing, some evidence was obtained on small‐scale “do‐it‐yourself” systems, which were aimed principally at developing countries or community groups. The latter included a UK‐based study, which considered UK legislation, such as the Animal By‐Products Regulations. No direct evidence, however, was identified on manufacturing capital equipment, as existing suppliers would presumably have patented their technology.

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Gaps Skills gaps will be largely determined by the current EU Skills’ study.

• The NNFCC research into locations of current and planned AD sites will inform geographical research needs.

• Whilst there is an evidence gap in the published literature as regards “encouraging an environment that minimises barriers to AD”, it is apparent that much of the work of the AD working groups relates to this priority area.

Recommendations • It would be useful to assess what training courses are available internationally, and assess

the appropriateness of incorporating these into UK training modules

• The nature of training required will also depend to a certain extent on the delivery models of AD taken up in the UK‐ e.g. small scale on farm co‐digestion or community AD, versus larger scale centralised processes. The EU skills activity will support the adoption of relevant training to identified needs.

• Both vocationally related qualifications and higher level awards are available in the UK on related topics. In order to avoid duplication of materials, where practicable, it is suggested that an appropriate supply of existing information be carried out prior to new material development.

• As a number of on‐farm digesters have been constructed as “DIY” projects in other European countries (e.g. Germany), there could be merit in investigating this further to identify whether component manufacture could be effectively carried out in the UK. (This links with the recommendation in Section 4.8)

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4.5 Smarter Regulation DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• Is the current regulatory framework the best that it can be or is there some room to improve?

• How do we enable the use of digestion capacity within the water industry?

• How do we ensure that operators can make the best use of biomethane for heat and for transport?


Table 7 – Evidence summary: Smarter regulation




Toolkits Case

studies Comments

Continue to improve the regulatory process, guidance and training

Ongoing work e.g. protocols, exemptions. This links to: technical expertise elsewhere in Europe and building UK skills

Clarify when biogas is no longer a waste C C

There is a wealth of information about biogas composition and use in EU countries

Clarify and simplify the regulation of waste at sewage treatment works.

C

Wealth of information about AD to treat waste water / sewage. Limited information on other waste treated or STW, some transferable information.

Identify and remove regulatory barriers (where they exist) to biomethane injection into the gas grid and to the use of biomethane as a transport fuel

M M

Links to Transport theme. Moderate information from Europe. Some ongoing research into UK specific issues: thresholds and regulatory practice etc.


Summary There is a wealth of supporting technical evidence to underpin regulatory requirements (as described under the AD landscape section), in addition to the UK water industry’s experience of operating AD plants at waste water treatment works. In particular, there is a wealth of information about biogas composition and use in European countries.

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During this study the authors identified minimal research into emissions from AD plants, although we understand that this subject has been addressed in Defra’s study WR 0608 Emissions from Waste Management Facilities (ERM). It is unclear as to whether this covers aspects such as odour or detail on bioaerosols.

The production and composition of biogas, also has relevance to the AD Landscape, Building UK Skills and Transport work streams.

Recent DEFRA research into exemptions for small scale AD plants in Europe has been undertaken and there is some ongoing research into Health and Safety issues associated with biomethane injection into gas grid. It was observed that there is also European research covering similar areas.

Gaps Due to the particular requirements of UK‐based regulation, it was difficult to identify specific evidence gaps relating to this work stream. A gap was raised and noted as regards odour information from AD plants, with limited information identified through this analysis.

Where gaps in evidence were barriers to development or deregulation, these are being addressed through protocols, specifications and some research work (e.g. for thresholds of contaminants) and subject to consultations.

Recommendations • There have been a number of technical reports published in German covering aspects such

as “Weaknesses in biogas plants – understanding and prevention”, and “A Comparison of Biogas Plants” which could usefully be translated into English.

• There may be scope to further investigate key nuisance issues such as odour from AD facilities and also bioaerosol emissions as part of further research in this area.

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4.6 Building Safe and Secure Markets for Digestate DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How do we ensure that digestates are recognised as a safe and secure source of renewable fertiliser?

• How do we develop new markets for digestates?


Table 8 – Evidence summary: building safe and secure markets for digestate




Toolkits Case

studies Comments

Build confidence in the use of digestate. P M L

Benefits and risks less well documented compared to composts. Long term application of food waste only digestate less well understood

Promote the use of existing standards and best practice advice

L L

Most of the reports are published by WRAP European summaries by the European Compost Network

Develop and disseminate a robust evidence base that will allow technical debate of the benefits and potential hazards associated with the use of digestate products

P P P

Evidence base on hazards is strong in sewage sludge Weak on plant and certain animal / human pathogens. Limited ‘food waste only’ digestate evidence.


Summary The evidence search for this work stream was hampered by the interrelated use of terms used to describe what we in the UK call digestate. These, for example, included: AD residues, biofertiliser, biosolids, sludge, slurry, biogas residues, press water (separated liquor). The scope of this study did not allow for a detailed investigation of evidence under all of these search terms.

The evidence on the long‐term use and benefits of sewage sludge, which would presumably encompass a significant proportion of materials treated anaerobically, is particularly strong (e.g. through research carried out by UKWIR). Similarly, the biological and chemical hazards present in sewage sludges have been well characterised and risk assessed through a body of evidence in this area.

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The use of digestate resulting from manures (both liquid and solid) tends to be reported in terms of its nutrient content, whilst the presence of human and animal pathogens is assumed to be less than untreated manures.

Recent work on PAS 110 and related WRAP and DEFRA research adds to the relevant evidence base.

Gaps The key gaps identified are outlined below:

• Long term benefits of digestate ‐ Other than for sewage sludge, there appeared to be little evidence available on the long term benefits of digestate application to land, such as crop growth, soil improvement (structure and microbial activity), disease suppression, and the presence (and potential build‐up) of hazards.

• Food waste‐derived digestate ‐ Other than research commissioned primarily by WRAP and also some Defra research no direct evidence was found on digestates derived from food wastes.

• Digestates from mixed waste feedstocks – Little evidence was identified (although there was some UK characterisation3); however, this may have been exacerbated by the variability in search terms.

• Weed seed and propagules – The evidence base for weed seed and plant propagule destruction is poor, in particular, with regard to weeds of concern within the UK.

• Novel uses of digestate – Evidence was not identified during this study.

• Thermal treatment or other applications of digestate unsuitable for use/ markets to land ‐ were not identified, this has significance for residual waste treatment using Mechanical Biological Treatment(MBT) or Mechanical Heat Treatment (MHT) technologies.

Recommendations • WRAP’s current focus on food waste‐derived digestate should improve the evidence base,

including benefits to plants and soils. This should be continued in order to ascertain benefits and identify if the long term use of digestate on agricultural land may become problematic

• A more detailed investigation looking into the potential hazards in digestate (e.g. pesticide residues, weed seeds / propagules) could usefully be carried out. This could complement WRAP‘s risk assessment work on composts. Again, this is important to ensure the long term application of digestate to land is beneficial environmentally and economically

• The evidence on the sanitisation of the pathogen Clostridium botulinum appears to be weak, and an assessment of research needs should be carried out

• Outlets and environmental implications for digestate from residual treatment processes should be explored4

3 WR0212 DEFRA research report ‐ Optimising the inputs/outputs of Anaerobic Digestion processes, 2009. 4 Some research has taken place from DEFRA new technologies funding on digestion of autoclave residue.

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4.7 Building Markets for Methane and Transport Fuels DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How do we ensure that operators can make the best use of biomethane for transport fuels?


Table 9 – Evidence summary: building markets for methane and transport fuels




Toolkits Case

studies Comments

Understand the issues of low uptake of biomethane as a transport fuel.

C C

Case studies and reports on use of biogas as a transport fuel in Sweden, Germany


Summary The evidence search for this work stream was also complicated by the interrelated use of terms, such as biogas and biomethane, which are sometimes used in subtlety different contexts. There was also a significant cross‐over between evidence obtained under the Landscape, Regulation, Finance and Awareness work streams.

Barriers to the uptake of biogas as a transport fuel appeared to centre around a lack of national infrastructure.

Case studies reporting biogas upgrading and associated technologies have been published by Task 37 (references are cited in Appendix 7).

Gaps Substantial regulatory and economic activity is taking place as regards this aspect, there were no significant gaps identified that are not being addressed through current work.

Recommendations • A review of the “key success factors” that have made the use of biogas as a transport fuel in

other countries (in particular Sweden) could usefully be carried out to assess what could be transferred to the UK. This could look into infrastructure issues, as well as fiscal incentives (e.g. for fleet and company vehicles).

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4.8 AD in the Rural Community DEFRA’s priority areas for this work theme are set out in the December 2010 framework document:

• How do we ensure that the development of a robust AD industry includes an increase in on farm scale AD plants?


Table 10 – Evidence summary: AD in the rural community




Toolkits Case

studies Comments

Encourage industry to develop models and capital equipment that is appropriate at the farm scale level.

P P

There are some case studies and web sites aimed at on‐farm manure management. The models would benefit from further practical supporting measures.

Ensure that the body of existing work that has been undertaken on farm scale operations is made available to farmers in accessible format.

M M

There are some reports on decentralised systems in Germany, Austria and Sweden

Ensure that we understand the impact of growing energy crops on potential land‐use change

M M M M

Wealth of information about digesting energy crops that could allow theoretical estimates of land use to be made


Summary There is significant cross over with other work streams, such as the AD Landscape, Awareness and Regulation streams.

There are a number of case studies illustrating how decentralised on‐farm AD systems have been implemented in other countries, and as such these could be used to show case to the farming community.

A significant amount of research has been undertaken assessing biogas yields from energy crops, and some of this data has been incorporated into process modelling tools. This data could also be used to make theoretical estimates of land use for biomass crops.

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The digestion of cover crops (e.g. grass and clover) has been documented, although these crops may not always form part of a farmer’s typical rotation. A significant programme of work is currently underway in Ireland investigating the digestion of grass.

Gaps • Capital costs and downsizing of equipment – Although this has been discussed under other

work streams, it remains a significant gap in the UK evidence base.

• Evidence of functional contractual arrangements – between farmers/operators, waste management contractors and local government for example.

• Evidence on management of rejected feedstocks – no research was identified in this area.

Recommendations In addition to those recommendations made elsewhere in this report, the following would improve the UK evidence base:

• Assess the state of the art of on‐farm AD systems in Europe (in particular, Austria and Germany), to identify “key success factors” and downsizing issues, especially where DIY AD systems have been constructed.

• Seek to address evidence gaps around working models for on farm AD e.g. centralised pasteurisation, tripartite contracts etc.

• Seek evidence on rejected feedstocks / procedures etc.

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5 Addressing the Gaps Table 11 identifies the key gaps in evidence highlighted by the study, and suggests (in the authors’ view) a priority for each gap in terms of a low, medium or high priority, these are also taken as a proxy for timescale of addressing the gap (i.e. short = high priority, long term = low priority). The nature of the gap is proposed, as regards whether it is research oriented or applied in nature. The table also indicates the sector most likely to be best placed to take responsibility for addressing the gap, defined as Government5 or Regulator or Industry.

As detailed in Section 2 (Methodology), the priorities were ranked according to the following criteria:

• High = Cross‐cutting, addresses gaps in a number of work streams; generally UK‐specific; generally a short‐term intervention; may impede the development of AD in the UK if not acted on;

• Medium = Addresses gaps in a few work streams; intervention may need to be carried out over a longer period of time than those ranked as High; and

• Low = Addresses gaps in only a small number of work streams; evidence gaps may be addressed by other parties in due course; Unlikely that failure to address the gap will impede the development of AD in the UK

5 Includes ‘arms length’ or other whole or part Government funded delivery bodies such as WRAP and NNFCC

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Table 11 – Identified gaps, priority ranking and suggested stakeholder responsibility

Gap Priority Nature Responsibility Commentary

1. Up‐to‐date, accurate information on the current size of the AD sector

Medium Research Government &

Industry

Investigate the feasibility of either: reviewing and updating the NNFCC’s Biogas Map on an ongoing basis (to ensure site data are accurate) or; incorporating AD into DECC’s RESTATS and REPD databases

2. Characterisation and understanding of primarily food waste feedstocks and digestion High Research Government

Continue to investigate the long term implications of food waste digestion to understand the process parameters, operating conditions and outputs from the process

3. Municipal interfaces with AD treatment

High Research Government

Independent assessment of wet vs. dry AD systems, the best systems for different feedstocks and the interface with collection systems is an area that could merit investigation.

4. Financial: capital costs, operating costs and revenue Medium Research Industry

Review and collate capital costs of AD plant components to improve the accuracy of financial model toolkits.

High Research / Applied

Government & Industry

A review of self‐built AD systems in Germany and the ways in which this could be transferrable to the UK in order to reduce capital costs for small‐scale systems and assist the UK’s nascent manufacturing base.

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Incorporate results from ongoing research into biogas yields from food wastes into existing process models, as this will enable better estimations of likely revenue from AD plants to be made

5. Financing of Community Scale Projects High Research

Government & Industry

Improved information on financing options, including industry – community joint ventures

6. Collating existing information on AD into usable formats on specific topics

High Collation Government &

Industry

Summarise key existing findings rather than ‘new’ research in areas such as:

o Technologies available and appropriateness to different feedstocks; and

Medium Research Industry Quantifying, where possible, the wider benefits of AD (such as carbon benefits, job creation and community benefits etc.);

7. Case study transferability

High Translation Government

Technical translation of key scientific reports published in other languages, particularly German, into English


A critical review of published European case studies could be usefully carried out to identify the key success factors and whether these could be transferrable to the UK. A simultaneous study to identify how and why other projects failed and the contributing reasons

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8. Communication

Medium Public

Relations Industry

There is a need for communications materials for AD for local stakeholders to explain the role and impact of facilities. Reference to other industry initiatives (e.g. quarrying) could be made.

9. Stimulating the growth in AD technologies through different business models


A study be undertaken to review the working models (contractual and economic) for the successful development of AD in other countries (e.g. Germany, Austria and Sweden) and the effects these have had on the growth and development of AD over the past decade. This could build on other work undertaken (e.g. Defra research) and usefully provide a framework in which the developing AD sector in the UK could be assessed.

10. Training needs

Medium Research Industry

Largely to be identified through ongoing (EU Skills) activity. Some existing training and qualifications awards available in the UK and overseas, important to avoid unnecessary duplication of effort. It would be useful to assess what training courses are available internationally, and assess the appropriateness of incorporating these into UK training modules.

11. Regulatory issues High Translation Government

There have been a number of technical reports published in German covering aspects such as “Weaknesses in biogas plants – understanding

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and prevention”, and “A Comparison of Biogas Plants” which could usefully be translated into English.


Government / Regulator

There is scope to further investigate key emissions & nuisance issues such as bioaerosols & odour from AD facilities as part of further research in this area.

12. Applications of Digestate

Medium Research / Applied

Government

WRAP’s current focus on food waste‐derived digestate should improve the evidence base, including benefits to plants and soils. This should be continued in order to ascertain benefits and identify if the long term use of digestate on agricultural land may become problematic


Government

A more detailed investigation looking into the potential hazards in digestate (e.g. pesticide residues, weed seeds / propagules) could usefully be carried out. This could complement WRAP‘s risk assessment work on composts. Again, this is important to ensure the long term application of digestate to land is beneficial environmentally and economically.


Government The evidence on the sanitisation of the pathogen Clostridium botulinum appears to be weak, and an assessment of research needs should be carried

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out

Medium Research / Applied

Government Outlets and environmental implications for digestate from residual treatment processes should be explored

13. Biogas as Transport Fuel

Medium Research Government

A review of the “key success factors” that have made the use of biogas as a transport fuel in other countries (in particular Sweden) could usefully be carried out to assess what could be transferred to the UK. This could look into infrastructure issues, as well as fiscal incentives (e.g. for fleet and company vehicles).

14. Evidence of functional contractual arrangements using on farm digestion Low Applied

Government / Industry

Seek to address evidence gaps around working models for on farm AD e.g. centralised pasteurisation, tripartite contracts etc.

Low Applied

Government / Industry

Seek evidence on management of rejected farm wastes / feedstocks etc.

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6 Defra’s AD Strategy Research Work Stream In parallel to this study, Defra has liaised with a range of stakeholders to identify priorities under each of the eight work streams. As part of this process, actions for further research were suggested by the steering group, which are shown in the Table 12 below. The extent to which these issues have been addressed, or where evidence exists is shown has been commented upon.

Table 12 – Research issues raised by Defra’s AD steering group and extent to which evidence exists

Issue Main action to address issue RMA Comment

Help industry and research bodies identify remaining knowledge gaps and research needs

Develop a clear dialogue between research bodies and industry to ensure that market needs are underpinned by relevant R&D.

An existing portal e.g. the NNFCC’s Biogas Portal or WasteNet could usefully be updated to signpost researchers and industry to existing areas of expertise and evidence identified in this study.

Raising awareness of managing discarded materials is a key issue.

Defra R&D gap analysis could possibly look at this?

There is a wealth of information (primarily about processing issues and theoretical biogas yields) about digesting a range of waste materials. The Agrobiogas toolkit contains some useful information.

Industry could be signposted to the portals listed above to obtain further information about the usefulness of digesting some discarded materials.

There is an overall need for data collection and evidence (carbon reductions etc)

‐ Some gaps exist, although evidence exists in documents written in languages other than English e.g. German. Technical translation of key documents should help identify where the gaps lie.

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Include R&D on utilising cover crops for AD energy value

‐ There is currently a large programme of work being undertaken in Ireland looking into digesting grass.

Ley crops have been used widely elsewhere, and the use of energy crops reported on e.g. Task 37 documents.

The Agrobiogas toolkit contains information about a range of energy crops.

Farming bodies should be able to advise on the appropriateness of incorporating energy crops into UK crop rotations; however an economic assessment should also accompany this, due to the potentially greater biogas yields associated with energy crops compared with other feedstocks. The occasional use of cover crops (e.g. every few years) in digesters may not be attractive to farmers, who may wish to digest them every year.

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Appendix 1 – The AD Landscape Evidence Base This work stream covered a wide range of topics, of which there was significant cross‐over with other work streams. The evidence could be categorised as containing either time‐sensitive or time‐insensitive data.

Size Number of plants, location, capacity etc. There were a number of evidence sources available:

• NNFCC portal (http://biogas‐info.co.uk/maps/index2.htm), which lists most (but not all) of the AD plants either in operation or under construction across the UK. This is reliant on self‐completion by industry, hence there is no verification of records;

• WRAP annual organics survey, which now includes a detailed analysis of AD (2009 survey; in press). However, due to its nature it is an historic overview and therefore does not contain up‐to‐date information; and

• WRAP Environmental Transformation Fund – the Anaerobic Digestion Demonstration Programme is being run by WRAP and will contain detailed information about five funded UK AD projects

None of these evidence sources provide up‐to‐date information on the “state of AD in the UK”.

Feedstocks – Types There is a wealth of information available about feedstock types, pre‐processing, biogas yields etc, focussing primarily on energy crops, manures and “municipal waste” (although it is sometimes not clear if these refer to mixed or separated fractions). Peer‐reviewed academic papers are generally published in the journals Bioresource Technology, or Waste Management and Research.

Notably there does not appear to be a great deal of published evidence on food wastes; the UK appears to be taking the lead in this respect.

Evidence on feedstocks is cited in other appendices of this report.

Feedstocks quantities – how much, where and modelling arisings in the future This is a UK‐specific issue where the evidence base is low. There is a feedstock availability tool on the NNFCC portal (http://www.biogas‐info.co.uk/index.php/ad‐map.html); however, this does not appear to have been updated recently.

The authors understand that Defra has commissioned some research in this area, including a horizon scan until 2050, although this is not available as the work in ongoing.

In general, there is a need for more up‐to‐date information, published in a format that is publicly available.

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Financial – Capital costs, operating costs and revenue Some evidence exists describing indicative capital costs, for example, small‐scale on‐farm digesters6 & 7, micro AD system8 and larger‐scale digesters9. The latter are described in detail in two reports with accompanying detailed spreadsheet toolkits, namely:

• Investment Decision Tool Manual (2008) Agrobiogas

• A Detailed Economic Assessment Of Anaerobic Digestion Technology And Its Suitability To UK Farming And Waste Systems 2nd Edition (2010) The Andersons Centre

Process optimisation and characterisation There is a vast amount of information on process modelling and reactor performance and their effect on biogas yields (for example 10 & 11), including some early UK‐based Good Practice Guidelines12, and the subsequent impacts on revenue.

Agrobiogas have produced a Toolkit13 to allow AD systems modelling, depending upon feedstock input and processing conditions. Notably, the toolkit does not include food wastes, although it provides a wealth of technical information (e.g. substrate characteristics and gas yields) about energy crops and single substrate wastes.

There is also the European Agricultural AD Helpdesk, which is an EC sponsored initiative through the Agrobiogas consortium, which provides free expert advice. See: http://www.adhelpdesk.eu/website/index.htm

University of Adelaide (Australia) hosts a Beginner’s Guide to Biogas web site14. There are numerous documents on small‐scale DIY systems, process kinetics and dynamics. There is also a simple process monitoring toolkit15, which models the effect of input volatile solids, operating temperature and retention time on the digestion of different waste types in a "Continuous Flow Stirred Tank" digester.

In summary, there is a need for better capital cost estimates to be made available, that could usefully be used in either of the two financial model toolkits constructed by Agrobiogas and the Andersons Centre.

6 Clayton, M., Leaney, N., Olie, A. & Robbins, A. (2009) Economic Modelling Of Low Tech, Low Cost Anaerobic Digestion / Biogas Installations In A Range Of Rural Scenarios In Cornwall, The Isles Of Scilly And Exmoor N ational Park. Aardvark EM Ltd. 7 USDA (2010) Anaerobic Digestion Costs for Dairy Farms. AgSTAR 8 Development of decentralised anaerobic digestion systems for application in the UK Phase 2 (2010) Lettinga Associates Foundation 9 The Economics of Dairy Anaerobic Digestion with Coproduct Marketing (2009) Review of Agricultural Economics—Volume 31, Number 3—Pages 394–410 10 Frost, P. & Gilkinson, S. (2010) First Year Performance Summary of Anaerobic Digestion of Dairy Cow Slurry at AFPI Hillsborough. AFBI. 11 International Guidance for Quantifying and Reporting the Performance of Anaerobic Digestion Systems for Livestock Manures (2010) Methane to Markets 12 British Biogen (2000) Anaerobic Digestion of Farm and Food Processing Residues Good Practice Guidelines 13 Agrobiogas Database Toolkit 14 See: http://www.adelaide.edu.au/biogas/ 15 Digicalc (2010) Toolkit. Paul Harris [Accessed 8 March 2011]

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Appendix 2 – The Raising Awareness – Community AD and Localism Evidence Base Defra’s interest in this area focuses around information and communication.

Information case studies and examples As AD is well established in other countries, there exist a number of case studies illustrating how systems have been applied in various situations. This evidence is of variable quality and depth. The principal examples are summarised below:

UK evidence

• The National Farmers’ Union web site16 includes a few AD case studies, relevant to the farming sector

• WRAP provides information on the Environmental Transformation Fund, which includes case studies of five AD projects either recently commissioned, or in development17

• The NNFCC Biogas Portal describes AD in general within a UK context18

In addition to examples of extant and upcoming sites, there are a number of recent studies suggesting rural and / or community AD models19 and Clayton et al. (2009) in the UK. Although theoretical, they provide a useful framework for further consideration by Defra.

International evidence

These are of variable quality and robustness; however, many are informative and paint an interesting picture about the different contexts in which AD plants operate outside of the UK. The key sources of information include:

• International Energy Association Task 3720 ‐ This site provides some useful case study reports21222324252627, mainly from Austria and Sweden. In addition, the annual country reports provide an overview of the “state of play” in each individual contributing country

16 See: www.nfuonline.com 17 See: http://www.wrap.org.uk/recycling_industry/information_by_material/organics/etf.html 18 See: http://www.biogas‐info.co.uk/ 19 A Toolbox Guide For Assessing The Feasibility of an Anaerobic Digestion Project Developed for the Benefit of a Community or for a Single Farm (2010) Sustainable Youlgrave 20 See: http://www.iea‐biogas.net/casestudiestask.htm 21 Wet Fermentation Technology for Bio‐Wastes. Task 37 22 Austria's First Feeding of Upgraded Biogas to the Natural Gas Grid Task 37 23 Optimised Digestion of Energy Crops and Agricultural Wastes in a Local Biogas Plant in Reidling, Austria Task 37 24 Energy Crop Digestion Plant – Strem 25 Injection Of Biogas Into The Natural Gas Grid In Laholm, Sweden Co‐Digestion Of Manure And Industrial Waste 26 Biogas From Slaughterhouse Waste: Towards An Energy Self‐Sufficient Industry 27 Biogas from manure and waste products ‐ Swedish case studies

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• USDA AgSTAR programme28 – This provides detailed information about digesting animal manures, with case studies for farmers

• Methane to Markets29 – this provides summaries of contributing country action plans. Although some are dated, they provide an indication of the role AD may play in different countries with different geopolitical compositions.

• The Wales Centre of Excellence for AD, based at the University of Glamorgan contains useful case studies on UK and European AD plants30

Communications As communication is a two‐way, dynamic process between developers and local communities, there was no evidence identified during the research illustrating how this has been implemented in practice. Examples of existing AD systems benefitting the local community (e.g. through a district heating system) were cited by Task 37 in Austria and Sweden, and community‐based models were discussed in the Sustainable Youlgrave report.

Cranfield University (School of Applied Sciences) is currently undertaking an EPSRC‐funded project (EP/H043861/1) researching the “Community acceptance of new waste management facilities ‐ a public engagement pilot‐project”. This is being led by Drs Sean Tyrell and A. Angus, and is due to report in July 2011. Although this doesn’t specifically focus on AD, the proposed public engagement partnership may well have relevance to Defra.

In addition, a paper presented at the RICS rural research conference (ROOTS 2008) highlighted some of the specific issues involved in obtaining planning applications for AD plants31.

Reducing capital costs of smallscale plant technology This was an area where little direct evidence was available. However, there were a number of examples of small‐scale (micro) AD and self‐build systems, aimed either at community groups or developing countries that could usefully be assessed for wider application across the UK. The key sources are listed below:

• Community Composting Network (CCN)32 – This describes a theoretical micro AD system suitable for use in decentralised applications. The work by the CCN is ongoing.

• University of Adelaide, Beginner's Guide to Biogas site33 ‐ This contains numerous documents and links covering small‐scale DIY systems & process kinetics / dynamics

• Journey to Forever34 – This contains numerous documents and links aimed at small‐scale DIY projects

• Faith And Sustainable Technologies35 – This is a group which aims to provide support to developing countries. It describes the design, operation and use of micro AD plants in

28 See: http://www.epa.gov/agstar/anaerobic/index.html 29 See: http://www.globalmethane.org/agriculture/index.aspx and http://www.globalmethane.org/tools‐resources/ag_techproceeds.aspx 30 See: http://www.walesadcentre.org.uk/CaseStudies/CommercialandIndustrial.aspx 31 Butler, A., Hobbs, P., Stevens, B. & Winter, M. (2008) Expanding anaerobic digestion plants in the UK: the challenges of perception and planning. ROOTS 2008 Conference Proceedings 32 See: http://www.communitycompost.org/index.php/projects/mad 33 http://www.adelaide.edu.au/biogas/ 34 http://journeytoforever.org/biofuel_library.html

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developing countries. Many of the books are out of print and are published by FAST as scanned PDFs.

35 www.fastonline.org

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Appendix 3 – The Building Investor Confidence Evidence Base This work theme is an area where there is scant direct evidence, or published research. However, there is indirect evidence available from countries such as Austria, Denmark and Germany, which have well‐established AD sectors; these can be reviewed to see how the growth of AD has changed as feed‐in tariffs have varied over the past decade. This provides an indication of how confident investors are in the construction of new AD plants.

Evidence is available from the following sources:

• International Energy Authority Task 37 Country reports archive36 – this provides a useful summary of the development of AD across Europe. Of particular interest, is the 2009 report for Austria, which demonstrates how the development of new AD plants increased following the introduction of feed‐in tariffs

• ENCROP have published a very useful report37 highlighting problems experienced in a number of EU countries. Although it relates primarily to energy crops, it provides a useful insight into AD issues, including fiscal incentives and operational issues.

An assessment of the various fiscal incentives in place to promote AD and the use of biogas in other countries would be a useful exercise, as both macro and micro economic frameworks will directly influence investor confidence.

Appendix 4 – The Building UK Skills Evidence Base The evidence base for this work theme is limited. There exists a wealth of technical data and information, which can be used by UK industry38 however, in itself, this will not necessarily ensure the workforce has the requisite skills to run a safe and environmentally sound business.

Only one example of direct help was identified outside of the UK:

• European Agricultural AD Helpdesk39 – This is aimed at farmers and investors. Two simulation toolkits, one modelling digester performance, and one modelling investment parameters, have been developed (cited under Appendix 1). The AD helpdesk remains operational, with support available in the UK.

36 See: http://www.iea‐biogas.net/publicationsreports.htm#may10 37 Problems and concerns affecting uptake of energy crop cultivation and use (2010) ENCROP 38 e.g. Defra research setting out monitoring methods and operating parameters etc. 39 See: http://www.adhelpdesk.eu/website/index.htm

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Appendix 5 – The Smarter Regulation Evidence Base Due to the specific requirements of UK‐based regulation, it was difficult to identify evidence that was of direct relevance to this work task. However, there is a substantial amount of information about AD processes, emissions and biogas that would provide scientific evidence to underpin this work. There is considerable overlap between other work themes (AD Landscape, Building UK Skills and Transport). The key areas are detailed below.

There are a number of research groups that currently have an interest in biogas and AD:

• International Biogas and Bioenergy Centre of Competence (IBBK)40 – This is a German network of experts and companies working in anaerobic digestion, biogas and bioenergy. It aims to provide technical information about AD, and runs training courses. The IBBK has produced a number of reports414243, which are mostly in German and have relevance to a number of work themes.

• UK Water Industry Research (UKWIR) – This is a UK‐based organisation that carries out research on behalf of the water industry. Its focus therefore centres around sewage and waste water treatment. In particular, it has recently published a report about biogas and its potential uses.44

• German Biomass Research Centre (DBFZ)45 – this is a German not‐for‐profit research organisation, with a department focusing on biochemical conversion. Its main focus is the study of the technical, economic and ecological efficiency of biogas production and use. This group has published numerous reports, with many in German that could benefit from technical translation.

• Agency for Renewable Resources (FNR)46 – This is an Agency founded by the German Federal Ministry of Food, Agriculture and Consumer Protection). It has produced a number of useful publications474849. The latter (A Comparison of Biogas Plants) compared AD plants, and investigated the reliability of the systems and the quality of the products. This report is in German and there could be benefits from technical translation into English.

40 See: http://www.biogas‐zentrum.de/ 41 Schwachstellen an Biogasanlagen verstehen und vermeiden (Weaknesses in biogas plants understanding and prevention) (2009) IBBK 42 Bioenergie für Kommunen (Bioenergy for local authorities) (2005) IBBK 43 Betriebszweigabrechnung für Biogasanlagen (Accounting for biogas plants) (2006) IBBK 44 Sewage treatment ‐ Maximising the Value of Biogas (2009) UK Water Industry Research Ref: 09/WW/05/4 (ISBN: 1 84057 534 4) and 09/WW/05/5 45 See: http://www.dbfz.de/web/Biochemical‐Conversion.114.0.html?&L=1 46 See: http://www.fnr‐server.de/cms35/index.php?id=139 47 Biogas – An Introduction (2009) FNR 48 Biogas ‐ Basisdaten Deutschland (Biogas ‐ Basic data for Germany) (2010) FNR 49 Biogas‐Messprogramm II: 61 Biogasanlagen im Vergleich (A comparison of biogas plants) (2010) FNR

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Other sources of evidence about biogas, include the:

• International Energy Agency Task 37 – they have published a number of reports on biogas composition, upgrading and use; technical reports include50515253, whilst example case studies illustrating the use of biogas include5455565758.

A recent paper suggested using the carbon dioxide in biogas to grow microalgae59.

50 Biogas Production and Utilisation Task 37 51 From Biogas to Green Gas ‐ Upgrading Techniques and Suppliers Task 37 52 Biogas upgrading technologies – developments and innovations Task 37 53 Biogas Upgrading to Vehicle Fuel Standards and Grid Injection Task 37 54 Austria's First Feeding of Upgraded Biogas to the Natural Gas Grid Task 37 55 Optimised Digestion of Energy Crops and Agricultural Wastes in a Local Biogas Plant in Reidling, Austria Task 37 56 Energy Crop Digestion Plant – Strem Task 37 57 Injection of Biogas into the Natural Gas Grid in Laholm, Sweden Co‐Digestion of Manure and Industrial Waste Task 37 58 Biogas from Slaughterhouse Waste: Towards an Energy Self‐Sufficient Industry Task 37 59 Kastánek, F., Sabata,S., Solcová, O., Maléterová, Y., Kastánek, P., Brányiková, I., Kuthan, K. & Zachleder, V. (2010) In‐field experimental verification of cultivation of microalgae Chlorella sp. using the flue gas from a cogeneration unit as a source of carbon dioxide Waste Management and Research 28: 961

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Appendix 6 – Safe and Secure Markets for Digestate Evidence Base The evidence search was complicated by the interrelated use of different terms, depending upon context: terms such as digestate, AD residues, biofertiliser, biosolids, sludge, slurry, biogas residues, press water (separated liquor), for example, were used.

Sewage sludge The long‐term evidence on the use of digested sewage sludge is well documented, including work in the UK by a consortium of organisations and reported to Defra (see, for example60) and the European Commission61. UK Water Industry Research (UKWIR) has published extensively on the use of sewage sludge, which would include materials treated in anaerobic digesters at waste water treatment works. Their focus has been on nutrient management, pathogens, effects on soil microbial activity and organic contaminants. The evidence base on persistent organic pollutants, in particular, is strong, with a significant body of work having been carried out by the EC62.

Digestate Hazards that may be present in other digested materials appear to be less well documented, compared to sewage sludges. Digested manures generally tend to be treated and used in a similar manner to raw manures: the benefits and application rates tend to be expressed in nutrient terms63. A useful recent summary has been published by Task 3764. Although animal and human pathogen destruction has been documented, this does not appear to be as rigorous as sewage‐derived digestates. There is a lack of evidence on the fate of the obligate anaerobic bacteria, Clostridium spp. that can cause diseases such as botulism (David Tompkins, WRAP, personal communication).

The evidence base for weed seed destruction appears to be poor. There have been some studies carried out in the USA65 Sweden66 and Austria, of which the latter are published in German.

There appears to be little long‐term evidence relating to the effects of digestates on soils quality, crop responses and soil microbial activity. Some research has been published (see, for example, 67), with trials on‐going in both the UK (funded by WRAP) and in Ireland (funded by rx3). There appears to be little evidence of the fate and turnover for N and C from digestate from different sources in soil and the effects on soil processes (Prof David Manning, University of Newcastle, and Florian

60 Effects of sewage sludge on agricultural productivity and soil fertility (Phase III) ‐ SP0130 (2006) DEFRA study 61 Environmental, economic and social impacts of the use of sewage sludge on land (2009) European Commission 62 Pollutants in urban waste water and sewage sludge (2001) European Commission 63 Agrobiogas (2009) Recommendations for AD sludge utilisation as a biofertilizer 64 Lukehurst, C.T., Frost, P. & Al Seadi, T (2010) Utilisation of digestate from biogas plants as biofertiliser, IEA Task 37 65 Katovich, E.J, Becker, R.L & Doll, J. (2004) Weed Seed Survival in Anaerobic Digesters, The Minnesota Project 66 Haraldsson, L. (2008) Anaerobic digestion of sugar beet – fate of plant pathogens and gas potential. MSc thesis, University of Uppsala 67 Organic Residues a Resource for Arable Soils (2005) Monica Odlare; PhD thesis

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Amlinger, Austrian Biogas Association, personal communications). One paper was identified that characterised C and N mineralisation of compost and digestate68.

Most of the literature relates to use of digestate, but where the fibre and liquor have been separated, there's a need to better understand how this behaves once applied to land (e.g. in terms of C and N dynamics, plant available nutrients, separation of contaminants etc.) Recent studies in Ireland suggest that there was a big variation in the quality of digestate and that the concentrations of phosphorous and nitrogen changed significantly AFTER storage indicating that changes were occurring during storage69. This merits further consideration / research.

Other than research published by WRAP, there appears to be scant evidence on the properties of digestates derived from food wastes. In countries such as Italy where separately collected food wastes are anaerobically digested, the majority are post‐composted before land application70.

68 Luxhøi,J., Bruun, S., Jensen Stoumann, L., Magid, J., Jensen, A. & Larsen, T. (2007) Modelling C and N mineralization during decomposition of anaerobically digested and composted municipal solid waste Waste Management and Research 25: 170 69 Heslop, V. (2011) Results of the Rx3 Funded Crop Demonstration Trials Using Compost and Digestate. Paper presented at AD 2011, Dublin. 70 Confalonieri, A. (2011) Drivers for Anaerobic Digestion Integration in Organic Waste Recovery Strategies. Paper presented at AD 2011, Dublin.

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Appendix 7 – The Building Markets for Methane and Transport Fuels Evidence Base There were strong links here with the Regulation, Finance and Awareness (scientific – biogas yields) work streams. As with digestate there was some interrelated use of terms, such as biogas and biomethane.

A reasonable amount of evidence was obtained for this work stream, although these were generally in the form of case studies or technical reports.

There are a few countries where biomethane is used as a transport fuel: namely Sweden and Germany. There are a number of case studies published by Task 37717273 and the Swedish Biogas Association74

There does not appear to be any technical reasons why biogas cannot be used in transport, as it is similar to compressed natural gas (Prof Richard Stone, University of Oxford, personal communication).

Some of the issues encountered in the UK, are also being addressed by other countries, such as Germany75. In a recently published a report76, the European Expert Group on Future Transport Fuels concluded that: “Biomethane should preferentially be fed into the general gas grid. Methane powered vehicles should then be fed from a single grid. Additional refuelling infrastructure has to be built up to ensure widespread supply”. This view was also recounted to the authors by Arthur Wellinger (personal communication), President of the European Biogas Association, who noted that the increased use of biogas for transport purposes in Germany is limited by available infrastructure.

71 Biogas Upgrading to Vehicle Fuel Standards and Grid Injection (2006) Task 37 72 Biogas upgrading technologies – developments and innovations (2009) Task 37 73 100% Biogas For Urban Transport In Linköping, Sweden. Case Study – Task 37 74 Biogas from manure and waste products ‐ Swedish case studies (2008) 75 The role of natural gas and biomethane in the fuel mix of the future in Germany ‐‐ Required action and potential solutions to accelerate adoption in transport applications (2010) DENA 76 Future Transport Fuels (2011)

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Appendix 8 – The AD in the Rural Community Evidence Base There is considerable overlap between this work stream and the AD Landscape, Regulation, Finance and Awareness work streams. As such, the evidence presented elsewhere has not been repeated here.

There is a wealth of information about the use of energy crops in anaerobic digesters (see, for example7778), which could enable the UK to calculate the potential land area required for a range of AD sizes. There exists some evidence in peer reviewed journals on the land use impacts of bioenergy crops, although these are not limited to feedstocks in AD.

Evidence about small‐scale systems was aimed primarily at developing countries, although it was acknowledged that innovation in specialist equipment was required to downsize it to small‐scale applications was required (Jan Habart, Czech Biomass Association, personal communication).

There are a number of case studies and reports highlighting small‐scale decentralised systems (for example79), and those referred to under “AD Landscape”.

77 Biogas from Energy Crop Digestion, Task 37 78 Energy from field energy crops – Sustainable energy production with direct combustion or biogas technology (2010) ENCROP 79 The first bioenergy village in Jühnde/Germany ‐ Energy self sufficiency with biogas, Task 37

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Appendix 9 Glossary

AD Anaerobic digestion

ADBA Anaerobic Digestion and Biogas Association

Defra Department for Environment, Food and Rural Affairs

DECC Department for Energy and Climate Change

IEA International Energy Authority

NNFCC National Non Food Crop Centre

PAS 110 Publicly Available Specification

REA Renewable Energy Association

REPD (DECC) Renewable Energy Planning Database

RESTATS Renewable Energy STATisticS Database (commissioned by DECC)

STW Sewage Treatment Works

UKWIR UK Water Industry Research

URL Uniform Resource Locator

USDA US Department of Agriculture

WRAP Waste and Resources Action Programme

Anaerobic Digestion Evidence Availability and Gap Analysis · 2015-02-11 · Prof David Manning...

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