Pretreatment of Waste Newspaper Using Ethylene Glycol for Bioethanol Production

Abstract

Pretreatment using ethylene glycol was investigated to enhance the enzyme digestibility of wastepaper The pretreatment was conducted over a wide range of conditions including sulfuric acid concentrations of 1 3 similar to 4 7%, temperatures of 143 2 similar to 176 7 degrees C and reaction time of 1 6 similar to 184 min The optimum conditions were around 2% sulfuric acid, 150 degrees C and 15 min At these conditions, 60 and 75% of hemicellulose and lignin, respectively, were removed while cellulose remained intact Additionally, an enzyme digestibility of 94% was achieved From the substrate dissolution analysis, the dissolution yield was strongly related to the enzymatic digestibility and the removal of cellulose, hemicellulose and lignin Also, the dissolution yield was directly related to the seventy parameter, which provides a quantitative prediction of the intensity of a reaction Recycling and re-use of ethylene glycol were also studied Ethylene glycol could be recycled and re-used at least four times without significantly lowering the pretreatment performance