Biogas : opportunities to improve safety and safety regulation

Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 36 BIOGAS: OPPORTUNITIES TO IMPROVE SAFETY AND SAFETY REGULATION Olivier SALVI1, Christine CHAUBET1, Sébastien EVANNO2 1 European Virtual Institute for Integrated Risk Management (EU-VRi), Stuttgart, Germany, [email protected] 2 Institut National de l’Environnement Industriel et des Risques (INERIS), Accidental Risk Division, Verneuil-en-Halatte, France, [email protected] Abstract: The production of biogas is positioned as energy which can not only generate a source of renewable energy but also which recycles waste. In the context of sustainable development, the place of biogas is therefore essential. Several questions about safety issues, the harmonization of the regulations and the need to develop standards are discussed in this paper, based on the results of a workshop on biogas safety and regulation organized in November 2010 and the activities of the European Working Group on Biogas Safety and Regulation created after the workshop. The risks corresponding to the biogas production and use have been framed using iNTeg-Risk method and tools. Several defi cits for risk management have been identifi ed and a strategy to improve risk management proposed by the working group is presented at the end of the paper. Key words: Biogas, Safety, Regulation, Risk management. Introduction Biogas is a promising energy resource in the context of the new European Energy Strategy 2020. It represents a valorization of wastes (water or biomass) and can be produced all over Europe for a great variety of applications: transport, stationary energy use, heat and combustion. The main emerging risk issues related to the quick development of biogas, which is fl ammable, toxic, and possibly pathogen (microbiological hazard), are: - the diversity of processes (from waste water treatment to solid waste treatment, or biomass valorization by farmers) without reference document clearly defi ning at international level the state of the art regarding safety, - the lack of clear regulations and standards regarding safety of biogas production and use, and the lack of enforcement of the existing occupational health and safety regulation (including ATEX), - the lack of organized communication channels to share the experiences (near-misses, accidents, and also positive experiences) between the industry players, but also with the usual stakeholders such as authorities, insurance companies, the public. N.B.: The smell which is often considered as an environmental issue is not addressed specifi cally in this document. The European Working Group on Biogas Safety and Regulation (EWGBSR), created after the Workshop organized by EU-VRi and INERIS in Paris in November 2010, has joined the iNTeg-Risk project in 2011. This project provides a framework, methods and tools to start structuring the sector from a risk management point of view. The participation in the project is performed by having “Biogas safety and regulation” as a new ERRA (Emerging Risk Representative Application) whose objective is to accompany the deployment of biogas in Europe with a high level of safety. It means that the approach and tools developed within iNTegRisk have been implemented in the working group. These methods and tools are helpful to manage the emerging risks of biogas and they constitute a full test of the results of iNTeg-Risk project. This paper presents the ideas developed in a “briefi ng paper” prepared by the EWGBSR. It describes the emerging risk issues related to the production of biogas. The objective of the “briefi ng paper” is to raise awareness about the emerging risks among policy makers and risk managers at corporate level. It is aimed at providing synthetic information on safety issues related to biogas to the target group about possible solutions based on the implementation of the iNTeg-Risk solutions, and therefore it might support the launch of further initiatives on risk management related to biogas. First of all this paper provides a general presentation of the trends of biogas production in Europe and the legislation currently in force. Secondly, the main biogas safety issues are presented Research article p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 37 as well as the trends in terms of accidents in Europe. Then the application of the iNTeg-Risk approach and tools is described with eventually some proposals for improving risk management. Materials and methods Biogas development and European policy context • Background information Biogas is an energy resource developing very fast in Europe. In 2010, primary energy production from biogas enjoyed an annual growth of 31.3 % to reach a production of 20.9Mtoe (Observ’ER, 2011). There are three major production channels: - Sewage sludge gas represents 9.8 % of total production (1.1 Mteo). - Landfi ll gas represents 26.8 % of total production (2.9 Mteo). - The remaining 63.4 % are produced from other deposits which cover purpose-designed energy conversion methanization plants (decentralized agricultural plants, municipal solid waste methanization plants, co-digestion and multi-product plants). This important increase in biogas production benefi ted mainly to: - Electricity production that represented 30.3 TWh in 2010 which is 20.9 % up on 2009. - Total heat consumption (from the transformation sector and for self-consumption by the end-user) that amounted to 1.5 Mtoe. - Another type of biogas recovery, biomethane injection (purifi ed biogas) into the natural gas grid that is booming in a number of countries such as Germany, Sweden, and the Netherlands. The development of “fuel-grade biogas” (natural gas quality) provides another possible opening. The EurObserv’ER survey indicates that the member states are already ahead of their electricity target and in line with their heat consumption forecasts. Indeed, the National Renewable Energy Action Plans (NREAPs) target a production of electricity from biogas source up to 64 TWh in 2020 (43.9 TWh in 2015 and 28.7 TWh in 2010) and the biogas heat is targeted to reach 4.5 Mtoe in 2020 (2.7 Mtoe in 2015 and 1.5 Mtoe in 2010). However much of the growth in primary energy production from biogas is happening in Germany (61 % of the primary energy production). Contrary to the others, Germany has made the choice to promote the use of energy crops. Political decisions to develop the biogas sector, both in regulation and fi nancial terms are crucial if the targets are to be met, but the public acceptance of the new energy systems is also an important component that has to be seriously taken into account. • Biogas production Biogas is produced from waste in biogas plants or anaerobic digesters (Salvi et al., 2011). The anaerobic digestion is the process which transforms organic matter into biogases such as methane and carbon dioxide. There are several processes for the production of biogas depending on the type of organic waste used. Indeed, biogas could come from several sorts of raw materials: - Sewage sludge, - Food waste, - Waste from food industry, - Manure from cows, pigs etc., - Residues from agriculture, - ”Energy” herbs and plants like maize, - Distillery by products, - Organic fraction of municipal solid wastes. The amount of biogas or the quality of the biogas which will be produced depends on the sort of raw material. Thus, the biogas production is very variable from one plant to another. It is also important to highlight the difference between biogas plant and anaerobic digester (biogas from landfi lls and biogas from digesters). There are a lot of technical aspects which depend from each other: Various raw materials mean different processes, different processes mean different amounts of gases, and different amount of gases mean different sorts of up-grading or removing. And fi nally, it appears impossible to fi x a global yield in order to study all uses of biogas or to identify clearly hazards and risks in a biogas plant. Tab. 1 Trace compounds of biogas from different biogas production plants Biogas CH4 [%] CO2 [%] O2 [%] N2 [%] H2S [ppm] Benzene [mg.m-3] Toluene [mg.m-3] Landfi ll 47 - 57 37 - 41 < 1 < 1 - 17 36 - 115 0,6 - 2,3 1,7 - 5,1 Sewage digester 6165 36 - 38 < 1 < 2 b.d. 0,1 - 0,3 2,8 - 11,8 Farm biogas plant 55 - 58 37 - 38 < 1 < 1 - 2 32 - 169 0,7 - 1,3 0,2 - 0,7 Note: b.d.: below detection p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 38 Then, it is important to understand the safety critical parameters and to establish a regulation on the production of biogas or to think about a possible standardization that is compatible with the variety of biogas production plants. • Energy policy context The safe development of biogas in Europe will be possible with a strong legislation to support its production. This paragraph maps the landscape of EU policy. The driving force behind the development and use of bioenergy is the Renewable Energy Directive (Directive 2009/28/EC) adopted in April 2009 by the Council and the Parliament of the European Union. This directive sets a common framework for the promotion of energy from renewable sources in Europe. The aim of this legislative act is to achieve by 2020 a 20 % share of energy from renewable sources in the EU's fi nal consumption of energy and a 10 % share of energy from renewable sources in each member state's transport energy consumption. The implementation of these objectives is supported by the European Strategic Energy Technology Plan (SET-Plan), initially settled in 2007 by the European Commission (COM, 2007). The objective was to increase, coordinate and focus EU support on key low-carbon energy technologies. There are 6 European Industrial Initiatives (EIIs) in the SET-Plan, including the European Industrial Bioenergy Initiative. The EIIs bring together the industry, the research community, the member states and the Commission and aim at the rapid development of key energy technologies at European level. In parallel the European Energy Research Alliance (EERA) works to align the R&D activities of individual research organizations to the needs of the SET-Plan priorities, and to establish a joint programming framework at the EU level. The SET-Plan is coordinated by the SET-Plan Steering group (SET-Group) and supported by European Commission's Information System for the SET-Plan (SETIS). A global strategy insisting on safety aspects has been established in the Communication “Energy 2020 - A strategy for competitive, sustainable and secure energy” (COM, 2010). This Communication sets out the energy priorities for the next ten years and sets the actions to be taken in order to tackle the challenges of saving energy, achieving a market with competitive prizes and secure supplies, boosting technological leadership, and effectively negotiate with our international partners. The strategy is structured around four priorities. Priority 2 & 3 specifi cally set high requirements on the development of safe technologies in an appropriate and effective regulatory context, reaching the public acceptance of the new energy technologies. The importance of biogas has been more particularly pointed out in the resolution of 12 March 2008 on sustainable agriculture and biogas (Resolution 2009/C 66 E/05). The European Parliament emphasizes the importance of biogas as a renewable energy resource for the future. This resolution highlights the benefi ts of biogas but also several threats on health and environment linked to biogas production, and make some recommendations to Member States and Commission: 13. Stresses that technical and management developments are expected in the near future which will further increase environmental and health benefi ts of biogas installations which use livestock manure, slurry and organic waste. The European Commission is also asked to provide support and in particular to enforce legislation for the development of biogas installations. Concerning safety aspects, the importance of reporting and sharing experience on best practices between Member States is emphasized: 39. Urges the Commission and Member States to develop a coherent biogas policy; asks the Commission to present a specifi c report on biogas and its promotion in the EU, outlining the necessary changes in Community and national law to facilitate further expansion of the biogas sector and pointing out the most effi cient ways of using EU funds and programmes, as well as giving best practice examples; asks also, in this regard, for an impact assessment of the various forms of biogas production on climate, the ecology of the landscape, rural incomes and worldwide security of food supply. 50. Calls on the Commission to ensure cooperation and coordination between Member States, including those who currently have no biogas installations, or just a small number thereof, so that they may learn about each other's best practices in relation to biogas installations through the sharing of knowledge and technology. Regarding the policy context, it gives a high priority to renewable energies, in particular to those that can be produced locally and in a distributed manner, such as biogas. At the same time, the shift to renewable energy has to be safe and secure. The infrastructures have to be adapted as well as the regulatory context. It means for the biogas, that the following challenges must be solved: - Assure the inherently safe design and operation techniques of biogas plants and usages. p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 39 - Reach the public acceptance of this renewable energy. - Capitalize the good practices in reference documents (guidelines) and in standards. - Support the development of a harmonized and cost-effective regulatory framework. Biogas safety issues • Main risks for biogas production Biogas production plants present three main risks: - The risk of explosion is the most studied because it is related to the production and use of a fl ammable gas which is composed mainly with methane (cf. Tab. 1). - The second major risk is toxicity due to the presence of H2S. It is a very toxic gas that is produced in anaerobic digestion. - The microbial risk is also to be considered, however chronic risk of inhaling pathogens and minor elements when using biogas is overshadowed by the two previous risks. The construction of a biogas plant and its maintenance should be well monitored in order to manage risks. Prevention of people from being exposed to those risks and checking of all materials (including corrosion) should be realized with the aim of making the production of biogas safer. • Analysis of accidents involving biogas A census of databases collecting accident analyses of biogas production was conducted in 2011 by INERIS for the Ministry of the Environment in France. The aim was to collect a feedback as complete as possible on the methanization activity from different national and international databases such as the databases ARIA from BARPI in France or ZEMA in Germany. Fig. 1 Number of accidents on installations producing Biogas in Germany The study from INERIS (Evanno et al., 2012) provides for the fi rst time a detailed analysis of accidents in France and in Germany. For example 140 accidents where identifi ed in Germany in 2009. The study describes the most probable scenarios and gives an indication of the severity of the past accidents. It appears from the study that most accidents that have occurred were fi res and in most cases their causes have not been identifi ed with certainty. The evolution shows that accidents are better controlled and consequently with smaller effects on and off site. Most of the reported accidents occurred within the storage area of the biogas plants. From the cases reported, no signifi cant impact on the environment was recorded, side effects were mostly small. The only consequence of fi res outside biogas plants are related to the formation of plumes made of smoke from burning waste. Typical incidents in biogas plants are listed below: - leakage in the storage tank and/or on the distribution network of the biogas, - leakage following the completion of work on site storage and distribution of biogas, - accidental release of H2S especially in mixtures of septic waste, - water pollution caused by effl uent discharge, - overfl owing sewage systems or storm-water control due to exceptional downpours, to equipment failures in the event of massive infl ux of water fi re suppression, - presence of dangerous products in the raw material used to produce biogas, - overfl ow, freezing of valves, high pressure inside the digester. The incident assessment shows that the functional units such as CHP plants, injection system of solid, pumps, pipes and valves and agitators, are particularly vulnerable, implying failures on safety system (loss of containment, leakage…). In general, the process of anaerobic digestion of biomass and waste generates a high risks probability (and health and environmental extension) during the course of operation and/or maintenance. The main hazards to consider are listed in order of priority in terms of occurrence probability: fi res, explosions, toxic gas emissions (H2S). Compliance with ATEX regulations and the drafting of document related to protection against explosions is a signifi cant measure to control such risks in the methanization sector. It is therefore necessary to ensure, depending on the biomass p. 36 - 43, DOI 10.2478/v10281-012-0010-0 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 160 140 120 100 80 60 40 20 0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 40 used, protection against explosion of fl ammable gases (CH4, CO, H2S and H2), protection against fi re and protection against the emission of toxic gases (including H2S). • Evolution of the regulations dealing with safety in several member states In 2011 the European Working on Biogas Safety and Regulation has developed a survey focusing on the following questions: - Are you aware of recent evolutions of the biogas regulation in your country? - Are you aware of technical guidelines related to safety at national or European level? This survey, that collected answers from 14 national experts from 6 different countries, provided an interesting overview of the situation in Europe. According to the results, it appears that a few regulation and guidance documents exist, but they are either too generic (e.g. SEVESO), either too specifi c (e.g. technical guideline for biogas transportation). Moreover the implementation of safety regulations on biogas plants is not harmonized throughout Europe. Thus, there is a real need for a common framework that can be applied for all production processes, all raw materials and all types of producers. Results Implementation of iNTeg-Risk approach • Use of iNTeg-Risk tools to frame the problems Problem framing is a qualitative step necessary to start developing risk management solutions. It places a particular importance on the need for all interested parties to share a common understanding of the risk issue(s) being addressed or, otherwise, to raise awareness amongst those parties on the differences related to the perceived risks. The project has produced a framework and tools, such as a template to carry out a common analysis of the various case studies. The use of the template provides an overview of the emerging risk issues of the case under consideration. The following aspects are systematically described: - General description, - Source of hazard, - Elements at risk to hazard, - Hazardous situation, - Main stakeholders, - Early warning situations, - Status description. The table hereunder gives a summary of the various aspects that help to frame the emerging risk issues for biogas. Tab. 2 The different steps to frame the risk management problems for biogas production • Stakeholders and their concerns It appears that the stakeholders involved in biogas production have very different visions and concerns about biogas, making diffi cult any consensus on the evolution of this sector. Concerns should tend to converge and fi nd common solutions in order to further develop the biogas production. General description Biogas differs from gas in petrochemicals due to three main characteristics that are important to take into account: - Biogas has been developed in very various sectors, very different safety and industrial cultures - Biogas operators are often public companies or institutions with different rules and logic than private sector. - Biogas is a biological process, not a chemical process Source of hazard The source of hazard is mainly related to the composition of the biogas, which is a toxic, fl ammable and pathogenic mixture. The context can also play an important role. Elements at risk to hazard The elements at risk are mainly the operators but can be extended to the environment, the population and even the whole community depending on the plants size and location. Hazardous situation The hazardous situations are: - Explosion and fi re - Toxic release - Microbiological release Main stakeholders The main stakeholders are the operators (public companies or municipalities) and the chain of operation (sub-contractors). Other stakeholders can also be involved: - Public - Local public authorities - Regulator (central government) Early warning situations A recent study describes the most probable scenarios and gives an indication of the severity of the biogas accidents. The number of accidents has signifi cantly increased in several member states (cf. Fig. 1). Status description A European Working Group on Biogas Safety and Regulation (EWGBSR) has been created in 2010 and is operating to bring more evidences on the risk management issues for the biogas production. p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 41 Tab. 3 List of stakeholders and their concerns • Identifi cation of defi cits The risk management defi cits for biogas production have been characterized using the set of tools developed with the iNTeg-Risk project. These tools have been extensively described in the proceedings of the three last annual conferences (Jovanovic et al., 2010, 2011, 2012). Tab. 4 Defi cits identifi ed for biogas risk management Proposal for improving risk management • Specifi c elements for risk management The development of a risk management strategy has to take into account the specifi c features of the biogas industry, which is in fact derived from several industry sectors, i.e. in particular: - Waste water treatment industry, - Solid waste treatment industry, - Agricultural industry. These sectors are structured differently, has different actors and different set of standards and regulations. These aspects are considered in this paragraph. Industrial rationale: - At the origin, Biogas is rarely the objective of the process but often a sub-product even sometimes considered as a “waste gas”. For example, in waste water treatment plant, biogas is the sub-product of the digestion process, the objective of which is to reduce volume and weight of the waste extracted from water. - Except for specifi c methanization plant, biogas process is rarely the main process of the plant, but just a part of. - Even if methanization process could be a critical one (ex: in WWTP), use of biogas is rarely critical except from a fi nancial point of view (ex: when it must be replaced by natural gas in boilers). Therefore, if biogas would not be easily considered as a safe and smart process, it might be withdrawn. Technical standards: - As experiences and contexts are various between the different sectors of operation, the technical answers are also different. These differences of technical answers could even begin differences of technical evidences. For example, using pipe in stainless steel is evidence in WWTP sector, but in rubbish dump sector, HDPE is. Stakeholder Concerns Public operators Control the cost of the main activities (waste or water treatment) Business continuity Operational costs Operating company Health and safety of the employee Business continuity Operational costs Diversity of process and options for the safety design Operator (agricultural) Health and safety of the employee Business continuity Operational costs Local public authorities Health and safety of the employee Business continuity Protection of the citizens Public in general Cost of energy Public in the vicinity of the biogas plant Odour Impact of accidents Public authorities (regulator) Long term sustainable operation Minimizing the risks for the society Cost effectiveness of the biogas sector Pre-assessment Risk Appraisal Tolerability & Acceptability Judg. Risk Management T: Technical/ Techno-logical Pretty good knowledge on the hazards of biogas No enough data available on the various situations for biogas production Lack of monitoring/ indicators about incidents and accidents Lack of specifi c technical guidance documents for safety H: Human/ Management Lack of education and safety culture Lack of risk perception studies No criteria available of risk tolerability. Lack of channels to share experience on incidents and accidents C: Governance/ Communi-cation Lack of awareness is observed Lack of concern assessment No discussion on risk acceptability has taken place. Lack of communication on the hazards and residual risks R: Policies/ Regulations/ Standards The problem is not yet clearly framed No cost-benefi t analysis and socioeconomic impact Lack of acceptability criteria Lack of harmonized regulation with a clear doctrine On-going initiatives in some countries to set up a safety regulatory framework p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 42 - Differences exist about the commonly acceptable level of MTBF or MTTR of the same equipments (ex: gas compressor, gas monitor), depending on the criticality. These differences between the levels of acceptability have a strong impact on the quality of the products proposed by the suppliers. - Methanization is a biological process with a great inertia. Therefore it cannot be stopped like a classic chemical process. So that, safety equipment and safety concepts must absolutely take this particularity into account without simply copying what’s done in petrochemicals. For example, in order to prevent a risk of explosion by introducing air in the methanizer, you could have some conditions which order its isolation. But with its inertia, methanizer will continue to produce biogas and pressure will increase until the safety valve opens, releasing the gas to the atmosphere. Regulations: - When they exist, regulations about biogas have been developed around the regulations already existing about the main activity of which biogas is issued. For example in France, methanization reactors of WWTP are not regulated by the industrial risk regulation but the water one. - Authorities in charge of monitoring activities of biogas operators, prioritize their action towards the core activities of biogas producers such as waste management or water quality. Therefore, regulations could be contradictory and authorities are not properly equipped to complete their mission of prevention. Safety culture: - Contrary to petrochemicals - where industrial risk management is fully part of their activity, in each step of process - biogas operators have to face such risks only in a small part of their activity. So, they do not master enough the different tools used in risk management like HAZOP. We can even affi rm that they are not really comfortable with the principles of industrial risks management. - Sectors in which biogas is operated, are internally linked around their main issues such as land effi ciency for agriculture or town planning policy for municipals. But they do not share together their experiences about biogas. In these conditions, a collective learning process has to be developed to improve the safety culture in the biogas industry. The current low level of safety culture and risk awareness prevents today to set up adequate harmonized minimum safety requirements all over Europe and in the various sectors of biogas. Raising the safety culture level is therefore a priority. • Proposal for a tailored-made approach to improve risk management In order to support the collective improvement of the safety level, the biogas industry sectors need to prepare a series of reference documents and guidelines. As a priority, the following documents and initiatives should be prepared rapidly, with the support of experts from industry and research organizations, specialized on industrial safety. - European general guideline that contains information on technologies of biogas production, regulatory context of biogas plants and advices on management of the setting up of a biogas plant. - European data base on accident, incident and near-misses providing an overview of the event with standardized information with the ability to search and fi lter the content by key words, technologies, contexts… - Catalog of proven technical solutions on piping class, demonstrated instrument technologies, severe conditions recommendation, specifi cs Process Flow Diagram. - Methodological guideline for the design of each type biogas plant with a presentation of the main accidents and their causes, a reminder of the specifi c questions or traps related to biogas and recommendations on the Process Flow Diagram. - Methodological guideline for biogas plant operation containing a presentation of the main accidents and their causes and information on the recommended controls and recommended methodologies to stop or start biogas equipment in safety. - European specifi c regulation on biogas production and uses defi ning the minimum safety design and equipment required, as well as the minimum operation procedures required and the organization of the monitoring. Conclusion Biogas is a very promising renewable energy resource that presents several hazards such as fi res, explosions, toxicity and microbial contamination. This paper presents an overview of the safety situation of biogas production. After a review of the production process, the trends in Europe as well as the legislation in force at European level, risks related to biogas production have been described. It is essential to frame properly biogas safety issues in order to improve risk management. Therefore iNTeg-Risk tools, which provide an effective framework, have been implemented for biogas to help framing the problems and developing a risk management strategy. p. 36 - 43, DOI 10.2478/v10281-012-0010-0 Transactions of the VŠB - Technical university of Ostrava Safety Engineering Series Vol. VII, No. 2, 2012 43 References COM (2007) 723. Communication from the Commission to the Council, the European Parliament, the European Economic and Social Committee and the Committee of the Regions: a European Strategic Energy Technology Plan (SET-Plan) - 'Towards a low carbon future'. COM (2010) 639. Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions: Energy 2020 - A strategy for competitive, sustainable and secure energy. Directive 2009/28/EC. Directive 2009/28/EC of the European Parliament and of the Council of 5 June 2009 on the promotion of the use of energy from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC. EVANNO, Sébastien (2012). Retour d’expérience relatif aux procédés de méthanisation et à leurs exploitations. Verneuil en Halatte, France: INERIS, 2012. 148 p. DRA-12-117442-01013A. JOVANOVIC, Aleksandar, RENN, Ortwin, SALVI, Olivier (2010). 2nd iNTeg-Risk Conference: New Technologies & Emerging Risks. Dealing with multiple and interconnected emerging risks. Stuttgart, Germany: Steinbeis Edition, 2010. 491 p. ISBN 978-3-938062-33-3. JOVANOVIC, Aleksandar, RENN, Ortwin, SALVI, Olivier (2011). 3rd iNTeg-Risk Conference & 20th SRA-Europe Meeting. Stuttgart. Germany: Steinbeis Edition, 2011. 152 p. ISBN 978-3-941417-65-6. JOVANOVIC, Aleksandar, RENN, Ortwin, SALVI, Olivier (2012). 4rd iNTeg-Risk Conference 2012: Managing Early Warnings - what and how to look for? Stuttgart. Germany: Steinbeis Edition, 2012. 67 p. ISBN 978-3943356-12-0. Observ’ER. (2011). The State of Renewable Energies in Europe. Paris, France, 2011. 127 p. 11th EurObserv’ER Report. Resolution 2009/C 66 E/05. Sustainable agriculture and biogas: review of EU legislation. European Parliament resolution of 12 March 2008 on sustainable agriculture and biogas: a need for review of EU legislation (2007/2107(INI)). SALVI, Olivier, DELSINNE, Samuel, EVANNO, Sébastien (2011). Biogas - A European Perspective on Safety and Regulation. Journal of Risk Analysis and Crisis Response. 2011, Vol.1, No. 1, pp. 1-20. ISSN 2210-8491. As a consequence, a series of documents and initiatives have been proposed: European general guideline; European data base on accident; incident and near-misses; Catalog of proven technical solutions; Methodological guideline for the design of each type biogas plant; Methodological guideline for biogas plant operation; European specifi c regulation on biogas production and uses. These actions will be set up by the EWGBSR with the aim to improve biogas risk management and consequently support the further and safe development of biogas in Europe. p. 36 - 43, DOI 10.2478/v10281-012-0010-0