title: Glycerol as an ionic liquid co-solvent for pretreatment of rice hulls to enhance glucose and xylose yield.
abstract: Rice hulls, a widely-available secondary agricultural residue, can be pretreated with ionic liquids (IL) prior to enzymatic hydrolysis to enhance glucose and xylose yields. The high cost of ILs is a deterrent to commercial deployment at present. ILs 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium formate, 1,3-dimethylimidazolium dimethylphosphate, and 1-ethyl-3-methylimidazolium diethylphosphate were investigated for rice hull pretreatment. Effects of diluting ILs with glycerol were investigated for biomass pretreatment efficacy, and for solvent recovery. When diluted with 50% glycerol, rice hulls treated in 1-ethyl-3-methylimidazolium formate was found to give glucose and xylose yields after enzymatic hydrolysis better than rice hulls treated in pure 1-ethyl-3-methylimidazolium formate. Dilution in glycerol resulted in an increased rate of solvent recovery after pretreatment, as much as six times that when pure 1-ethyl-3-methylimidazolium formate was used. Diluting 1-ethyl-3-methylimidazolium formate with 50% glycerol was found to decrease solvent viscosity at the pretreatment temperature (110 °C) helping explain improved biomass pretreatment.
authors.affiliation: Chemical & Materials Engineering Department, University of Nevada, 1664 N. Virginia St. MS 170, Reno, NV 89557, USA.
authors.forename: Joan G
authors.initials: JG
authors.lastname: Lynam
authors.affiliation: Chemical & Materials Engineering Department, University of Nevada, 1664 N. Virginia St. MS 170, Reno, NV 89557, USA. Electronic address: coronella@unr.edu.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Coronella
mesh_terms: D056804:Biofuels; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry*; D012275:Oryza; D012997:Solvents / Q000737:chemistry*; D014994:Xylose / Q000737:chemistry*
chemical_list: D056804:Biofuels; D007093:Imidazoles; D012997:Solvents; D014994:Xylose; D005947:Glucose; D005990:Glycerol
keywords: 1-Ethyl-3-methylimidazolium acetate; 1-Ethyl-3-methylimidazolium formate; Biomass; Delignification; Glycerin