以微波輔助鹼性過氧化氫前處理法 促進稻殼轉化乙醇之研究

Abstract

隨著工業發展與世界人口持續成長，全球對能源與糧食的需求量越來越高，未來各國勢必得面臨原油供應及油價、糧價飆漲的問題 ，而因纖維酒精以農業廢棄物為原料，不與民爭食又可做為液態燃料，故成為各國極力發展的替代能源之一。 本研究以我國農業廢棄物之一的稻殼為原料，利用微波加熱快速均勻的特性，搭配鹼性過氧化氫前處理法，處理已先用氫氟酸萃取出含矽成分之稻殼，並探討不同操作因子(加藥量、微波反應時間及微波反應溫度) 對前處理效果的影響，結果顯示在微波輔助前處理之最佳操作條件(100 %加藥量，微波反應時間15分鐘及微波反應溫度80oC)下，可將稻殼中纖維素含量從39 % 提升至72 %；且相較於傳統加熱方式，以微波加熱可將處理時間自45分鐘縮短至15分鐘，且提升10 % 之葡萄糖產量，具發展生質酒精的潛力。 以前處理過之稻殼針對不同操作因子(酵母菌量、反應溫度及反應時間)，進行同步水解與發酵(SSF)之最佳操作條件測試，結果顯示在10 g/L 原料、10mL/L水解酶、3 g/L酵母菌量、反應溫度40oC及反應時間48小時下，可獲得最佳乙醇產量3.21 g/L，其對應之產率為78 %。

With the increase of industrial prosperity and expansion of world population, the demands on food and energy have increased gradually. The fossil fuels are not renewable and will be exhausted in the near future. So it’s important to explore new energy sources and bioethanol may become one of the potential energy sources. This study intends to use rice husks as the raw material for bioethanol production. In this work HF was used to extract the SiO2 from the rice husks. And the microwave-assisted alkaline peroxide pretreatment was used to destroy the structure of rice husks. Raw rice husks contains about 39 % of cellulose, and after pretreatment (at reaction time of 15 min and reaction temperature of 80oC) the content of cellulose could reach to 72 %. In addition, the reaction time could be reduced from 45 min to 15 min at which the glucose yield could be increased by ~10 %. Thus the process developed in this study could be feasible to produce bioethanol from rice husks. The optimum operation condition for pretreated rice husks via simultaneous saccharification and fermentation (SSF) was at 10 g/L substrate, 10 mL/L cellulase, 3 g/L yeast loading, temperature of 40oC and reaction time of 48 hrs. Under the optimum condition the ethanol production concentration was 3.21 g/L and ethanol yield was 78 %.