The main objective of the Task 37 work programme is to address the challenges related to the economic and environmental sustainability of biogas production and utilisation. While there are many biogas plants in OECD countries, operation in the vast majority of cases can only be sustained with the help of subsidies to be able to compete with the fossil energy industrial sector. There is a clear need to enhance many of the process steps in the biogas production chain in order to reduce both investment and operating costs. This enhancement is now also required to effect significant decarbonisation and meet stringent sustainability criteria.
In 2013 – 2015 Task 37 produced reports on: substrates (sewage sludge, algae); pre-treatments including source separation of MSW; process optimisation (role of biogas in smart energy grids, process monitoring and nutrient recovery); and market development and trade of biomethane.
In 2016-2018 Task 37 reported on: substrates (food waste); optimisation of the sustainability of the produced biogas through measurement and minimisation of methane slippage at biogas facilities; system optimisation (greening of the gas grid; the role of biogas in circular economies; integrated sustainable solutions). Best practice in the lab was assessed through interrogation of the biomethane potential assay.
In 2019 – 2021 Task 37 reported on three broad themes: the role of biogas in energy systems; sustainability of biogas systems and methods to ensure good practice; and integration of biogas into processes.
To mitigate climate change, it is essential to develop integrated and sustainable decarbonised renewable energy systems. Heat and transport together, account for about 80% of final energy consumption. Significant progress has been made in renewable electricity but decarbonisation of transport fuel is problematic. Gaseous renewable energy carriers, such as renewable ‘green gas’ can have a considerable impact in future energy systems and play a key role in decarbonising heat and transport. Green gas at present is dominated by biomethane, which can be generated from the anaerobic digestion of organic biomass and residues produced in agriculture, food production and waste processing. The market for biomethane is still growing. Sweden, the UK, Switzerland, France, Denmark, China and the Netherlands have all increased their biomethane production significantly in the last five years. In the short term, the development of green gas projects, including the injection of biomethane to gas networks will be the primary focus of this developing industry. Management of this process will require a green gas certificate scheme to ensure sustainability and to allow trade.
Recent EU policy measures facilitate the development of such pathways with progressively increasing obligations on decarbonisation. The share in renewable and low-carbon transport fuels (excluding first generation biofuels and including for electrification) is required to increase from 1.5% in 2021 to 6.8% in 2030, with advanced biofuels to make up at least 3.6% by that time. Biomethane can provide this advanced biofuel for intercity buses and heavy commercial vehicles. Another driver is the demand from industry to lower the carbon intensity of their production. Agriculture and food in beverage industry in particular usually has a substrate basis for anaerobic digestion and potential customers for products with reduced carbon intensity.
In the 2022-2024 triennium the task will address the co-benefits of AD against this background, the conditions for a better manure utilization, the role of biomethane in industry and transportation and last but not least costs and marginal abatement cost. Within the technical questions, test systems and technologies for emission reduction are looked at.
Biogas technology can be seen as proven technology with thousands applications and numerous variants to handle specific site conditions. On the other sider there is still a vast potential of unused substrates which are available for a non-competitive and sustainable energy provision. The differences in the development worldwide are also mirrored in the task. In the extremes some countries are still struggling to set concise conditions for the start of a sector development, others as for instance Germany discuss what to do next with a sector with 10 000 plants in operation. As stated above, costs, acceptance and sustainability are the major points in the ongoing debate about biogas. The topics for the new triennium face these challenges and provide expert evidence in areas where biogas systems offer integrated and innovative solutions – which have benefits beyond pure energy provision. Renewable gas and in particular biomethane offer a carbon neutral energy carrier for sectors which cannot be substituted by electricity. It is obvious that biogas applications will not satisfy the energy demand of a whole nation. But we believe that the future energy system will be decentral, diverse and demanding a high flexibility; biogas can play a significant role in there. Evidence and advice is needed to ensure best practice and compliance with stringent sustainability criteria, whilst ensuring minimum cost of energy. An overarching challenge is the communication of the evidence to highlight the benefits of the biogas industry.