Abstract
Ozone is a powerful oxidant and is reactive toward lignin. Ozone can be used as an oxidant in pre-treatment process of lignocellulose material without producing any toxic residues nor making structural changes in cellulose and hemicellulose during ozonolysis process. This study aims to evaluate the effectiveness of ozone for the delignification of oil palm empty fruit bunch (OPEFB). The effect of 20, 40 and 60 mesh particle size, 30, 40 and 50% moisture content, and 30, 45 and 60 minute reaction time as well as their interactions, on lignin degradation, holocellulose content and reducing sugar concentration is investigated using response surface methodologies (RSM) with Design Expert 10. The total number of pre-treatment variations is determined by Box Behnken. The results show that ozonolysis is an effective method for delignifying lignin up to 63.86% and for increasing cellulose up to 40.95%. The ozonolysis process is able to degrade lignin and hemicellulose without decreasing the cellulose. The optimum condition of lignin degradation after the ozonolysis pre-treatment occurs at the condition with 40 mesh particle size, 50% moisture content and 30 minute reaction time. Enzymatic hydrolysis of OPEFB which has underwent ozonolysis pre-treatment can increase the concentration of reducing sugar. The optimum condition for lignin degradation is 42.42% and the reducing sugar concentration of 0.40 g / L is determined by the condition with 40 mesh particle size, 30% moisture content and 39.6 minute reaction time.
