Application of hydrodynamic cavitation (HC) for bioethanol production from rice straw

Abstract

A great deal of efforts for the economical production of bioethanol based on lignocellulosic biomass have been studied for few decades. Lignocellulosic biomass have focused on attractive feedstock due to its large amount and waste resources. In order to produce bioethanol using lignocellulosic biomass efficiently and cost effectively, removal of process inhibitors in their own complex structure is essential. Therefore, studying the pretreatment process that crushes entanglement in the structure have attracted increasing attention. Hydrodynamic cavitation with alkaline was applied to rice straw as an efficient and cost effective way of pretreatment from rice straw. In order to develop the pretreatment efficiency and operation continuity, modified cavitation zone (MCZ) was designed, and it was evaluated with the critical pretreatment parameters including concentration of NaOH (1-5%) and reaction time (5-15 minute) with 1:8 solid to liquid ratio. Under a pretreatment condition with NaOH 3% for 15 minute, the glucan content, enzymatic digestibility and glucose yield were 40.65 %, 73.73 % and 215.7 g/ kg of biomass, respectively. These results were obtained from enzymatic hydrolysis with 15 FPU of enzymatic dosage. We also examined physical property of pretreated rice straw using X-ray diffractometer. This study demonstrates that the hydrodynamic cavitation with new cavitation zone can be one of promising pretreatment tool for bioethanol production based on lignocellulosic biomass.