Exploring the feasibility of producing sustainable aviation fuel in the UK using hydrothermal liquefaction technology: A comprehensive techno-economic and environmental assessment

Abstract

Copyright © 2020 The Authors. Carbon emissions from the aviation industry are a significant concern and the adoption of sustainable aviation fuel has the potential of mitigating the environmental impacts. Hydrothermal liquefaction (HTL) has great potential to produce sustainable aviation fuel employing organic waste feedstock but requires further development to reduces costs and the environmental impact. This study focuses on examining the feasibility of an integrated HTL plant in the UK whilst investigating the potential to improve the energy efficiency of the process through heat integration and resource recovery from waste streams. The methodology adopted includes modelling an integrated HTL plant with a feed throughput of 10 ​t ​h−1 using Aspen Plus simulation approach. Techno-economic, regional resource and carbon footprint assessment are conducted on three different HTL configurations, i.e. a base case without energy and resource recovery; an HTL with heat integration; and an HTL with energy and resource recovery. Three different feedstocks (algae, food waste and sewage sludge) are investigated with sewage sludge feedstock found to have the lowest minimum fuel selling price of 0.50 £ l−1. Heat integration results in a 96.4% and 77.8% decrease in heating and cooling utilities and the economic assessment indicates that heat integration and resource recovery can reduce the minimum fuel selling price by 10.5% compared to the base case. The regional resource assessment reveals that 22.8% of UK jet fuel demand can be met with the technology. The carbon footprint assessment demonstrates that with maximum production, the technology can result in a 18.3% reduction of CO2 emissions relative to current aviation emissions. This study signifies that the integrated HTL process could play a pivotal role in mitigating carbon emissions in the aviation industry.