title: Supercritical carbon dioxide pretreatment of corn stover and switchgrass for lignocellulosic ethanol production.
abstract: Supercritical CO(2) (SC-CO(2)), a green solvent suitable for a mobile lignocellulosic biomass processor, was used to pretreat corn stover and switchgrass at various temperatures and pressures. The CO(2) pressure was released as quickly as possible by opening a quick release valve during the pretreatment. The biomass was hydrolyzed after pretreatment using cellulase combined with β-glucosidase. The hydrolysate was analyzed for the amount of glucose released. Glucose yields from corn stover samples pretreated with SC-CO(2) were higher than the untreated sample's 12% glucose yield (12 g/100g dry biomass) and the highest glucose yield of 30% was achieved with SC-CO(2) pretreatment at 3500 psi and 150°C for 60 min. The pretreatment method showed very limited improvement (14% vs. 12%) in glucose yield for switchgrass. X-ray diffraction results indicated no change in crystallinity of the SC-CO(2) treated corn stover when compared to the untreated, while SEM images showed an increase in surface area.
authors.affiliation: Department of Chemical Engineering & Biomolecular Engineering, Ohio University, Athens, OH 45701, USA.
authors.forename: Naveen
authors.initials: N
authors.lastname: Narayanaswamy
authors.forename: Ahmed
authors.initials: A
authors.lastname: Faik
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Goetz
authors.forename: Tingyue
authors.initials: T
authors.lastname: Gu
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000494:pharmacology*; D000431:Ethanol / Q000378:metabolism*; D005947:Glucose / Q000096:biosynthesis; D006868:Hydrolysis / Q000187:drug effects; D008031:Lignin / Q000096:biosynthesis*; D008855:Microscopy, Electron, Scanning; D008897:Panicum / Q000187:drug effects*; D011312:Pressure; D013696:Temperature; D013997:Time Factors; D014866:Waste Products / Q000032:analysis*; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D003313:Zea mays / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D014866:Waste Products; D014867:Water; C036909:lignocellulose; D002245:Carbon Dioxide; D000431:Ethanol; D008031:Lignin; D005947:Glucose