Environmental and economic impacts of using brewers spent grains for animal feed and anaerobic digestion

Davison, N., Christodoulou, C. ORCID: https://orcid.org/0000-0001-9465-3886, Humphries, D., Kliem, K. ORCID: https://orcid.org/0000-0002-0058-8225, Stergiadis, S. ORCID: https://orcid.org/0000-0002-7293-182X and Smith, L. ORCID: https://orcid.org/0000-0002-9898-9288 (2026) Environmental and economic impacts of using brewers spent grains for animal feed and anaerobic digestion. Journal of Cleaner Production, 538. 147365. ISSN 1879-1786 doi: 10.1016/j.jclepro.2025.147365

Abstract/Summary

Over 130,000 tonnes of brewer’s spent grains are generated annually in the UK. Most brewer’s spent grains are utilised as a low-carbon animal feed, although anaerobic digestion provides economic benefits, through generating heat, energy, and biofertiliser. This study addresses a research gap by comparing both the economic and environmental impacts of using brewer’s spent grains for animal feed versus anaerobic digestion. Specifically, it explores replacing brewer’s spent grains-derived cattle feed with either high-carbon soya or UK-grown field beans, including dietary implications on methane generation and indirect land use change. Life Cycle Assessment and Life Cycle Costing were used to evaluate the environmental and economic impacts of utilising all brewer’s spent grains generated in the UK for anaerobic digestion, as opposed to feeding cattle. Anaerobically digesting brewer’s spent grains and using soya feed to replace brewer’s spent grains as a cattle feed increased greenhouse gases by 39 Kt of CO2eq, while a field bean diet reduced emissions by 27 Kt of CO2eq. Additionally, the brewer’s spent grain cattle diet required 6 and 8 thousand hectares less land than the field beans and soya diets respectively. However, anaerobic digestion of brewer’s spent grains proved more profitable, offering an annual net economic benefit of £16 million. Thus, policy mechanisms such as an eventual ban could be introduced in order to phase out use of imported soya as an animal feed in the UK. Moreover, additional consultancy support, or interest free loans could be provided to facilitate breweries incorporating onsite anaerobic digestion.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/127620
Identification Number/DOI	10.1016/j.jclepro.2025.147365
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Animal Sciences Life Sciences > School of Agriculture, Policy and Development > Department of Agri-Food Economics & Marketing
Publisher	Elsevier
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