title: Evaluation of processing technology for Triarrhena sacchariflora (Maxim.) Nakai for ethanol production.
abstract: The effects of dilute H2SO4 concentration, forage:sulfuric acid ratio, digestion time, and digestion temperature were evaluated to determine effects on ethanol yield of Triarrhena sacchariflora (Maxim.) Nakai. Twenty single factor experiments were conducted to evaluate H2SO4 concentration (0.5, 1.0, 1.5, 2.0, and 2.5%, w/w), forage:sulfuric acid ratio (1:6, 1:8, 1:10, 1:12, and 1:14, g/ml), digestion time (15, 30, 45, 60, and 90, min), digestion temperature (80, 100, 110, 120, and 125 °C) for 3 replicates of the 5 levels of each factor. Based on results of the single factor experiments, an incomplete factorial was designed to evaluate ethanol yield from the best combinations of single factors. Finally, the best combination was tested by enzymatic hydrolysis and fermentation experiment in selected combinations according to pretreatment results. Percentage cellulose, hemicellulose, and lignin contents of forage residue after pretreatment, and glucose and xylose concentrations of the filtrate were analyzed prior to enzymatic hydrolysis, and percentage crystallinity was observed in untreated grass and pretreated residue. In addition, the solid residues were then hydrolysed and fermented by cellulase and yeast, the concentrations of glucose and ethanol being monitored for 96 h. Results showed that the order of the effect of main effect factors was as follows: digestion temperature > dilute H2SO4 concentration > digestion time > forage:sulfuric acid ratio. The best process parameters evaluated were sulfuric acid concentration of 1.5%, forage:sulfuric acid ratio of 1:6, digestion time of 15 min, and digestion temperature of 120°C. With this combination of factors, 80% of the cellulose was hydrolysed in 96 h, and 78% converted to ethanol. The findings identified that hemicelluloses were the key deconstruction barrier for pretreatment of Triarrhena sacchariflora (Maxim.) Nakai for ethanol production. The results of this research provide evidence of appropriate combinations of processing factors for production of ethanol from Triarrhena sacchariflora (Maxim.) Nakai.
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing 100193, PR China; Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, PR China.
authors.forename: Fengqin
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Fuyu
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing 100193, PR China.
authors.forename: He
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, PR China.
authors.forename: Qizhong
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Yunwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: B&B Research & Development, 16835 SW 27th St., El Reno, OK 73036, United States of America.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Brown
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D002480:Cellulase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008031:Lignin / Q000737:chemistry / Q000378:metabolism; D006109:Poaceae / Q000187:drug effects* / Q000378:metabolism*; D013464:Sulfuric Acids / Q000494:pharmacology; D013696:Temperature; D014994:Xylose / Q000378:metabolism
chemical_list: D013464:Sulfuric Acids; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin; D014994:Xylose; D002480:Cellulase; C019826:carboxymethylcellulase; D005947:Glucose; C033158:sulfuric acid