The Role of Anaerobic Digestion in Delivering a Net Zero Future

It is no secret that we have a waste problem. In a world of finite resources, the severity of the impacts of waste and convenience culture have become more visible. Efforts are being made to move towards a circular economy and with that, the rise in technologies that utilise waste as a resource.  In discussing circular technologies, anaerobic digestion (AD) is one worth highlighting as it addresses the issues of both waste and clean energy production. Organic waste generated from the breakdown of food waste, sewage sludge, agricultural slurries, crop waste, etc. generates methane which, according to the EDF, has more than 80 times the warming power of CO2 over the first 20 years after it reaches the atmosphere (Environmental Defence Fund). Simply put, AD describes the breakdown of organic matter by two groups of microorganisms: bacteria and archaea in an oxygen deprived (anaerobic) environment. AD captures these emissions produced during the breakdown of waste and produces biogas, which can be used as a clean, renewable energy for heat, transport, and even electricity (Anaerobic Digestion and Bioresources Association) as well as fertiliser in the form of the digestate. Furthermore, the carbon dioxide produced during the production of biomethane can be captured and sequestered.

According to the Anaerobic Digestion and Bioresources Association (ADBA), if AD is scaled up to full capacity and used to process all unavoidable wastes it could deliver a 6% reduction in total UK GHG emissions by 2030. That accounts for 30% of the carbon savings required in order for the UK to meet the UK’s 2030 target which was committed to in the 5th Carbon Budget. ADBA also argues that this would directly create 30,000 green jobs across the UK.

Waste to energy is in no way a substitute for waste reduction and avoidance. Instead, we are arguing that AD is a great technology for processing and utilising unavoidable waste.