Bio-oil Production from Food Processing Residues: Improving the Bio-oil Yield and Quality by Aqueous Phase Recycle in Hydrothermal Liquefaction of Blackcurrant (Ribes nigrum L.) Pomace

Abstract

Hydrothermal liquefaction (HTL) of wet organic waste is a promising technology for producing renewable liquid fuels. However, implementation of the process at commercial scales must overcome several challenges. Efficient management of the contaminated aqueous phase generated after the conversion is necessary to limit water treatment expenses. In this study, we suggest the direct recycling of the aqueous phase at the inlet of the HTL process. The purpose is to evaluate the effect of recycling the process water on the bio-oil recovery and quality. HTL of blackcurrant pomace was performed in a batch autoclave, at a temperature of 310 °C, with a holding time of 10 min, and a dry biomass concentration of 14.5 wt %. The influence of recycling the process water at the inlet of the process was evaluated for five recycle rounds. Recycling the process water has a positive effect on the bio-oil recovery, with the bio-oil yield increasing from 26 wt % to 31 wt % after five recycles. The energy recovery respectively i...