Pretreatment of <i>Miscanthus×giganteus</i> using aqueous ammonia with hydrogen peroxide to increase enzymatic hydrolysis to sugars

Abstract BACKGROUND Miscanthus×giganteus ( M.×giganteus ) is a potential source for bioethanol or other useful products. Pretreatment of lignocellulosic biomass is an essential step prior to enzymatic hydrolysis to sugars and fermentation to bioethanol . RESULTS In this work, a one‐step process uses aqueous ammonia with or without hydrogen peroxide; a proposed two‐step process uses aqueous ammonia in the first step and hydrogen peroxide in the second step. In the two‐step process, overall 89.5% lignin is removed. The pretreated biomass is followed by using cellulase and β‐glucosidase to convert cellulose and hemicellulose from the recovered solid to fermentable sugars. The conversion of cellulose to glucose is 90.2% and to xylose is 73.4%. Characterization data are obtained for the recovered solid using scanning electron microscopy ( SEM ), attenuated total reflection‐infrared spectroscopy ( ATR‐IR ), and X‐ray diffraction ( XRD ) for better understanding of the two‐step process . CONCLUSION Results from the two‐step process using aqueous ammonia and hydrogen peroxide separately are much better than those from the one‐step process for removing lignin and for enhancing conversion to sugars by enzymatic hydrolysis. © 2013 Society of Chemical Industry