Enhanced biomass processing towards acetone-butanol-ethanol fermentation using a ternary deep eutectic solvent
Helena Poy, André M. da Costa Lopes, Estela Lladosa, Carmen Gabaldón, Sonia Loras, Armando J. D. Silvestre
Abstract
This work evaluated the effectiveness of ternary deep eutectic solvents (DES) composed of cholinium chloride (ChCl), lactic acid (LA) and a diol (ethylene glycol – EG, or 1,6-hexanediol – HEX) in the pretreatment of rice straw (RS) towards the production of biobutanol. The most promising results were obtained with ChCl:LA:EG 1:5:5 at 120 °C for 4 h, which enabled the highest conversion of biomass polysaccharides into glucose and xylose up to 89.3 % and 53.6 % yields, respectively. Subsequently, the produced sugars were efficiently converted into biobutanol through the acetone-butanol-ethanol (ABE) fermentation process, resulting in the production of 95.7 g butanol/kg RS as one of the highest values reported in literature. Thus, the application of the ternary DES ChCl:LA:EG 1:5:5 represents a competitive and environmentally friendly pathway for RS valorization in comparison to conventional processes.