A Study on the Structure of Bagasse with Dilute Acid Pretreatment for Producing Bioethanol

• Main Authors: Yi-jian Tu, 凃伊建
• Other Authors: Wei-hsin Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/85808868243549197197

碩士 === 國立臺南大學 === 綠色能源科技研究所碩士班 === 98 === Dilute acid pretreatment is a commonly used pretreatment method in the course of producing bioethanol from lignocellulosics and the structure variation of the lignocellulosics is highly related to the pretreatment process. To understand the impact of dilute acid pretreatment on the structure of bagasse, four different pretreatment conditions by varying heating time are considered where the bagasse and the pretreated materials are examined using a variety of analysis methods. The obtained results indicate that the thermogravimetric analysis (TGA) is able to provide a useful insight into the recognition of lignocellulosic structure. Specifically, the peak of the TGA of the pretreated materials moves toward the low temperature region, revealing that the lignocellulosic structure is loosened. However, the characteristic of crystal structure of cellulose remains in the pretreated materials. Increasing heating time enhances the pretreatment procedure; as a result, the average particle size of the investigated materials increases with heating time. Disruption of lignocellulosic structure of biomass plays a key role in producing bioethanol from lignocelluloses. This study investigates the impact of dilute sulfuric acid pretreatment on bagasse structure using microwave heating. Three reaction temperatures of 130, 160 and 190 ℃ with two heating times of 5 and 10 min are considered and a number of instruments are employed to analyze the properties of the solid particles. On account of microwave irradiation into the solution with dielectric heating, the experiments indicate that an increase in reaction temperature destroyes the lignocellulosic structure of bagasse in a significant way. The pretreated bagasse particles are simultaneously characterized by fragmentation and swelling. When the reaction temperature is as high as 190 ℃, the fragmentation of particles become very remarkable so that the specific surface area of the pretreated material grow substantially. Meanwhile, almost all hemicellulose is removed from bagasse and the crystalline structure of cellulose disappeared. In contrast, the feature of lignin is exhibited clearly. However, a comparison between the heating times of 5 and 10 min reveal that the influence of the heating time on the lignocellulosic structure is not significant, indicating that the pretreatment with 5 min is long enough.