Bioethanol production from sweet sorghum bagasse through enzymatic process

Abstract

Bioethanol is one of renewable energy considered as fuel petroleum substitute. Generally, bioethanol can be obtained from raw material which contain of sugar, starch or lignocelluloses, i.e sorghum. The aim of this study was to obtain the optimum condition of NaOH concentration and cellulase:xylanase enzymes for bioethanol production from sweet sorghum bagasse. Raw material used was sweet sorghum bagasse. The experiment was conducted four stages: 1) characteristics of raw materials; 2) optimization effect of NaOH solution on delignification process, experimental design at this stage was completely randomized design (CRD) with 1 factor; 3) optimization effect of cellulase and xylanase enzymes (1:1% and (2:2%) to bioethanol production on scale of 500 g raw materials, statistical analysis that used in this stage was t-student test; 4) optimization process of bioethanol production on scale of 50 kg raw material. The results showed that the optimum condition to produced bioethanol from sweet sorghum bagasse was addition of 10% NaOH solution at a temperature of 120-130 0C for 20 minutes. Furthermore, the resulted material from delignification was proceesed to saccharification and hydrolysis using xylanase: Cellulase with ratio of 1:1. The bioethanol produced was 13.7% from total sweet sorghum bagasse powder used with alcohol content of 82.8%.