Effect of Tween-80 Addition in Dilute Acid Pretreatment of Waste Office Paper on Enzymatic Hydrolysis for Bioethanol Production by Shf and Ssf Processes

This paper describes the effect of the addition of Tween-80 in dilute sulfuric acid pretreatment on enzymatic hydrolysis of waste office paper. Lignocellulosic material was pretreated with dilute sulfuric acid (1% V/V) at 50 oC for 3 hours, with or without addition of Tween-80 (2.5 g/L). The pretreatment was able to remove hemicellulose and lignin from waste office paper, but the surfactant did not change the chemical composition of this material. In enzymatic hydrolysis (7 FPU/g substrate) with 5% of solids, the final glucose concentration was by about 50% higher (30 g/L for a duration of 72 hours) when the surfactant was added, irrespectively of whether the addition was done before or after the dilute sulfuric acid pretreatment. The SSF process was more efficient that the SHF process, since it required a shorter reaction time and similar ethanol concentration (about 12 g/L).