title: Study of chemical pretreatment and enzymatic saccharification for producing fermentable sugars from rice straw.
abstract: This study evaluated a cost-effective approach for the conversion of rice straw into fermentable sugars. The composition of rice straw pretreated with 1 % sulfuric acid or 1 % sodium hydroxide solution was compared to rice straw with no chemical pretreatment. Enzymatic saccharification experiments on non-pretreated rice straw (NPRS), pretreated rice straw (PRS), and pretreated rice straw with acid hydrolysate (PRSAH) were conducted in a series of batch reactors. The results indicated that pretreating the rice straw with dilute acid and base increased the cellulose content from 38 % to over 50 %. During enzymatic saccharification, straight aliphatic cellulose was hydrolyzed before branched hemicellulose, and glucose was the major hydrolysis product. The glucose yield was 0.52 g glucose/g for NPRS and was comparable to the yields of 0.50 g glucose/g for PRS and 0.58 g glucose/g for PRSAH. The hydrolysis of rice straw to produce glucose can be described by a first-order reaction with a rate constant of 0.0550 d(-1) for NPRS, 0.0653 d(-1) for PRSAH, and 0.0654 d(-1) for PRS. Overall, the production of fermentable sugars from ground rice straw will be more cost effective if the straw is not pretreated with chemicals.
authors.affiliation: Department of Environmental Engineering, National Ilan University, Yilan, 260, Taiwan, albert@niu.edu.tw.
authors.forename: Wen-Hsing
authors.initials: WH
authors.lastname: Chen
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chen
authors.forename: Jih-Gaw
authors.initials: JG
authors.lastname: Lin
mesh_terms: D000143:Acids / Q000737:chemistry; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry*; D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D004798:Enzymes / Q000737:chemistry; D005285:Fermentation; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D012275:Oryza / Q000502:physiology*; D011108:Polymers / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D013464:Sulfuric Acids / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D001617:beta-Glucosidase / Q000737:chemistry
chemical_list: D000143:Acids; D002241:Carbohydrates; D004798:Enzymes; D011108:Polymers; D011134:Polysaccharides; D013464:Sulfuric Acids; D012972:Sodium Hydroxide; C007916:hemicellulose; D002482:Cellulose; D001617:beta-Glucosidase; D002480:Cellulase; D005947:Glucose; C033158:sulfuric acid