Production of volatile fatty acids by anaerobic digestion of biowastes: Techno-economic and life cycle assessments

[Display omitted] •AD of grass and food wastes can be used to produce green VFAs.•Foreground uncertainty with the mass balance preservation with Monte Carlo LCAs.•GWP is reduced from 1 kg CO2 eq. for petrochemical production to −0.021 kg CO2 eq.•22 environmental impacts were lower for the AD of food waste, including the GWP.•Product’s price could vary from 1,491.23 to 1,864.04 GBP/ton. of VFA (NPV = 0). Production of volatile fatty acids from food waste and lignocellulosic materials has potential to avoid emissions from their production from petrochemicals and provide valuable feedstocks. Techno-economic and life cycle assessments of using food waste and grass to produce volatile fatty acids through anaerobic digestion have been conducted. Uncertainty and sensitivity analysis for both assessments were done to enable a robust forecast of key-aspects of the technology deployment at industrial scale. Results show low environmental impact of volatile fatty acid with food wastes being the most beneficial feedstock with global warming potential varying from −0.21 to 0.01 CO2 eq./kg of product. Food wastes had the greatest economic benefit with a breakeven selling price of 1.11–1.94 GBP/kg (1.22–2.33 USD) of volatile fatty acids in the product solution determined through sensitivity analysis. Anaerobic digestion of wastes is therefore a promising alternative to traditional volatile fatty acid production routes, providing economic and environmental benefits.