Simultaneous detoxification and bioethanol fermentation of furans-rich synthetic hydrolysate by digestate-based pyrochar

Abstract

Pyrolysis is a sustainable pathway to transform renewable biomasses into both biofuels and advanced carbonaceous materials (i.e. pyrochar) which can be used as adsorbent of furan compounds. In particular, the aim of this study was to: i) evaluate the effect of vibro-ball milling on physical characteristics of pyrochar and its consequent performance on solely detoxification of a synthetic medium, containing furans and soluble sugars; ii) study the simultaneous detoxification and bioethanol fermentation, by adding activated pyrochar into fermentation medium. Results demonstrated that, compared to untreated pyrochar, the use of milled pyrochar increased by 52% furfural removal from the synthetic medium. Furfural removal rate was also increased (adsorption kinetic constant increased from 0.015 min−1 up to 0.215 min−1), at a pyrochar loading of 40 g L−1. Although, the simultaneous addition of pyrochar into the fermentation medium did not improve the bioethanol yield of the synthetic medium, it has significantly increased the bioethanol production rate.