Pre-treatment combined H2SO4/H2O2/NaOH to obtain the lignocellulosic fractions of sugarcane bagasse

Abstract

The second generation ethanol (E2G) production process using residual lignocellulosic biomass such as bagasse and straw from sugarcane, has stimulated research to the use of different types of pretreatments that enhance the greater use of cellulose in obtaining the E2G. This process aims to reduce the crystallinity of the cellulose, favoring exposure to enzymatic attack. In this present study, sugarcane bagasse (SCB) was subjected to pre-treatment combined with dilute sulfuric acid 1.45% (v/v), followed by delignification with hydrogen peroxide 7.5% (v/v) and sodium hydroxide 4.0% (v/v). Chemical characterization was performed by high performance liquid chromatography (HPLC), by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) and scanning electron microscopy (SEM). The chemical pre-treatment evaluated preserved the cellulosic chain and allowed the removal of 85.8% (m/m) lignin and 70.7% (m/m) hemicellulose. The resulting biomass has mass percentage in cellulose of 39.5 and 45.1 as determined by HPLC techniques and ADF / NDF, respectively.