Developing On-site Anaerobic Digestion for Smaller Businesses in the Food and Drink Sector

Abstract

Development of Anaerobic Digestion (AD) in the UK has lagged behind other European member states. Focus on larger footprint plants has restricted the smaller scale (sub 250 kW electrical output) on-site AD sector, where energy can be generated from bio-residues at or close to the location where they are produced. Britain's food and beverage sector, as part of the transition to a more circular economy, must make better use of its raw materials by extracting value from unwanted residues (or co-products). Development of the bio-economy and on-site generation of decentralised energy should be part of the UK's industrial strategy prior to Brexit. There is considerable potential for bio-energy generation in the food and drink sector, including on smaller sites that proliferate across the food industry. More deployment of bio-energy needs less indifference from policy makers and more imagination from regulators. Also, the British bio-engineering sector needs to make the case for more proactive policy framework. The authors, based on their experience with on-site bio-digestion in the food and beverage sector, including plants for several multinational companies, explore how this approach could be deployed more widely, as part of the bio-economy, in the food and drink sector in Britain and across Europe. Definitions The Bio-economy encompasses the production of renewable biological resources and their conversion into food, bio-based products and bio-energy using innovative technologies. It offers new opportunities and solutions to a number of social, environmental and economic challenges, including climate change mitigation, energy and food security and enhanced resource efficiency. On-site AD: smaller scale deployment of the process used to generate bio-energy in a biological degradation process whereby micro-organisms that thrive without oxygen convert bio-degradable (volatile) process residues into renewable energy. Clearfleau's industrial AD plants convert liquid effluents and production residues into valuable bio-energy. Digestion Plant Scale – small, medium and large scale AD plants: A classification for AD was developed by the Renewable Energy Association (REA) and other partners for dealings with policy makers: small: on-site AD plants generating under 100 Nm3 of biogas or 200 kW thermal output, medium: plants generating >200 kW thermal but <2 MW thermal output, large: plants generating over 2 MW thermal (increasingly using gas to grid technology).