Optimisation of Small-Scale Anaerobic Digestion Systems in Cold Climates through Thermal Modelling and Cost-Benefit Assessment

Project ID: 2228cd1270 (You will need this ID for your application)

Research Theme: Energy and Decarbonisation

UCL Lead department: Civil, Environmental and Geomatic Engineering (CEGE)

Department Website

Lead Supervisor: Ilan Adler

Project Summary:

Across the UK and EU, livestock farming currently generates an estimate of 1.4 billion tons of manure annually, 90% of which is untreated, leading to increased global warming along with other environmental and health-related problems. Given appropriate management, this waste can produce a sustainable fuel (biogas) through anaerobic digestion (AD), a process involving microbial degradation of organic materials, with the potential of mitigating up to 6% of the UK’s overall greenhouse gas emissions. However, the large majority of farms in Europe (including the UK) are smallholders, usually run by single families, and without the financial capability to install a conventional AD facility. A downsized, lower cost version of the technology, known as small-scale AD(SSAD) has been succesfully tested by a number of emerging businesses in the region. Notwithstanding, adoption so far has been limited given the challenges imposed by colder climates, since the process is highly temperature-sensitive, coupled with a lack of understanding of the economics and tradeoffs involved as compared to larger-scale AD systems. The current project proposes addressing these research gaps through thermal modelling based on data from a number of ‘live’ pilot reactors, installed in smallhold farms across England, involving both fieldwork and lab testing at UCL. Based on the data collected throughout a period long enough to account for seasonal variations in performance, a full cost-benefit assessment (CBA) will also be developed, including the impact of different external heating mechanisms. The PhD candidate will be expected to develop a predictive model for various real-life scenarios, seeking to maximise biogas production while minimising operational costs and GHG emissions. The results and conclusions may pave the path in convincing small farmers to adopt SSAD, by reducing financial uncertainty while optimising energy production, facilitating widespread adoption of the technology in the UK and globally.