An electrogenerated base for the alkaline oxidative pretreatment of lignocellulosic biomass to produce bioethanol

Abstract

In this study, we aimed to develop an alternative base to substitute for NaOH for use in alkaline oxidative biomass pretreatment. An electrogenerated base (EGB) from water electrolysis was employed in the alkaline oxidative pretreatment of corn stover (CS). Similar to NaOH, when the EGB was used in pretreatment, 56.6% of the original lignin was removed after 6 h pretreatment, leading to significantly enhanced enzymatic digestibility. The glucan digestibility of the pretreated CS was 3.8 times higher than that of raw CS after 24 h. The ethanol metabolic yields were 64.6% and 72.4% when using activated carbon detoxified hydrolysate or hydrolysate at pH 5.5, respectively. These results demonstrate that an EGB, a byproduct from various electrocatalytic processes, could be used as a potential replacement for NaOH. Moreover, we propose a new biorefinery concept, which combines water electrolysis, biological conversion and thermochemical/catalytic conversion to produce bioethanol, hydrogen, hydrocarbon fuels and valuable chemicals.