Recycling the liquid fraction of alkaline hydrogen peroxide in the pretreatment of corn stover

[Display omitted] •Recycling of H2O2 in the corn stover biomass pretreatment is being proposed.•Delignification values had negative linear behavior in the recycles of H2O2.•Recycling H2O2 negatively affects the enzymatic conversion efficiency.•Recycling H2O2 is only effective for up to three cycles.•This methodology indicates reductions in 57.6% H2O and NaOH, and 59.6% H2O2 used. The aim of this study was to evaluate the influence of recycling the liquid fraction of pretreatment with alkaline hydrogen peroxide (AHP) on the hydrolysis of corn stover. Corn stover was pretreated in the traditional condition with 7.5% v/v H2O2. After pretreatment, the solids were separated from the liquid fraction and five successive reuse cycles of the liquid fraction were tested. The solid fraction from pretreatment in each recycle was submitted to enzymatic hydrolysis. The number of recycles had a linear negative effect (R2=0.98) on biomass delignification efficiency and also affected negatively the enzymatic conversion efficiency. Despite the decrease in efficiency after each recycling step, reuse of the liquid fraction leads to reduction in water, H2O2 and NaOH consumption of up to 57.6%, 59.6% and 57.6%, respectively. These findings point to an efficient recycling technology, which may reduce costs and save water.