Banks - Biogas production from high volume industrial effluents at ambient temperatures (AmbiGAS)

The project is formulated under the ERA-net programme and brings together an interdisciplinary team of academics, industrial process design engineers and end users from 4 countries. The research aims to develop in a systematic manner the concept of using anaerobic digestion (AD) at ambient temperatures for large volume, low-strength effluents produced in biomass-based process industries. Experience to date shows that low temperature AD is feasible, and the work will attempt to improve rates of reaction to match those of more conventional mesophilic systems. The research will establish the fundamental mechanisms underlying the acclimatisation of anaerobic microbial populations to low temperature conditions, and attempt to identify control parameters that will ensure rapid adaptation and stable operation. Reaction kinetics will be determined for different types of anaerobic biomass (granular, biofilm, dispersed or in flocs), and for industrial wastewaters from both food processing and non-food sectors. Studies will be carried out using laboratory-scale digesters to test different methods of retaining the anaerobic biomass by altering the reactor configuration, with a particular focus on the use of innovative membrane systems. The digesters will also be tested in conjunction with novel in-situ and side-stream biogas upgrading units, again using advanced membrane technologies. Our existing knowledge combined with the information gained in these targeted laboratory studies will be used to design a pilot-scale digester that will be trialled by one of the industrial end-user partners. The goal is to demonstrate the concept successfully at a pilot scale, while gaining sufficient knowledge and data to be able to show net energy production, and other savings calculated by using process models. The research outputs will provide process industries with the necessary information to make decisions on adopting these new technologies to take advantage of the potential energy savings. The research will also develop customised membrane-based gas upgrading systems to refine biogas to give methane that is pure enough for use as a vehicle fuel or direct injection into the gas network. Membrane systems will also be used to recover dissolved methane from treated effluent, which will not only increase energy yield but will also offer a solution to a major environmental issue, as methane is a powerful greenhouse gas that can contribute to climate change. The research is industry-linked, and the benefits and penalties of the new approach will be fully assessed using industry-standard process optimisation tools, which can provide the basis for further economic and environmental assessment. The research will have significant outputs in a range of areas: it will increase our scientific knowledge of methanogenic microorganisms, and improve process control in anaerobic systems; it will introduce new concepts in biogas upgrading and methane recovery, with added environmental benefits; it will create a database of effluent and process parameters to allow modelling and optimisation of biomass-based industries; and it will provide a practical demonstration of ambient temperature AD. The research and its implementation will thus provide a roadmap for the rapid uptake of this concept, which offers second generation biofuel production from a previously untapped source.