Pretreatment of Oil Palm Empty Fruit Bunch (OPEFB) using Microwave Irradiation

Lignocellulosic biomass is a promising alternative for bioethanol production. However, the conversion of its structural polysaccharides into simple sugar is highly problematic due to the recalcitrancy of lignin. Pretreatment lignocellulosic biomass is the most important step to remove lignin. Pretreatment is also required to alter the structure of cellulosic biomass to make more accessible to the enzyme that convert the carbohydrate polymer into fermentable sugars. There are several ways to increase the digestible cellulose before it is exposed to the enzyme: mechanical, physical, physico- chemical, chemical, biological pretreatment, as well as the combination of these methods. One of the physico-chemical methods is pretreatment using microwave irradiation. Objective of this research was to evaluate the potential of different acid catalyst (organic and anorganic) on water-glycerol media for microwave pretreatment of OPEFB. The OPEFB (40—60 mesh) were placed in cylindrical vessel then added liquid mixture of water-glycerol (solid to liquid ratio of 1:10) and organic (oxalic acid/ H2C2O4) or anorganic (sulphuric acid/ H2SO4) catalyst (1%), so that the ratio solid to liquid became 1: 20. Each pretreatment was exposed to microwave radiation on power level 50 and 70 % at 5—15 minutes. The highest sugar yield (29.15 %) with saccharification level (61.24 %) was obtained at power level 50 % for 15 min with anorganic acid (H2SO4) as catalyst. Proceedings of The 3Rd International Symposium of Indonesian Wood Research Society (IWoRS). Jogjakarta, 3-4 November 2011. ISBN 978-602-1905-30-2