title: Pretreatment of rice hulls by ionic liquid dissolution.
abstract: As a highly available waste product, rice hulls could be a starting block in replacing liquid fossil fuels. However, their silica covering can make further use difficult. This preliminary study investigates effects of dissolving rice hulls in the ionic liquids 1-ethyl-3-methylimidazolium acetate (EMIM Ac), 1-hexyl-3-methylimidazolium chloride, (HMIM Cl), and 1-allyl-3-methylimidazolium chloride (AMIM Cl), and what lignocellulosic components can be precipitated from the used ionic liquid with water and ethanol. EMIM Ac dissolution at 110 °C for 8 h was found to completely remove lignin from rice hulls, while ethanol was capable of precipitating lignin out of the used EMIM Ac. With 8h dissolution at 110 °C using HMIM Cl, approximately 20% of the cellulose in the rice hull sample can be precipitated out using water as co-solvent, while more than 60% of the hemicellulose can be precipitated with ethanol.
authors.affiliation: Department of Chemical & Materials Engineering, University of Nevada, Reno, 1664 N. Virginia St., MS0170, Reno, NV 89557, USA.
authors.forename: Joan G
authors.initials: JG
authors.lastname: Lynam
authors.forename: M Toufiq
authors.initials: MT
authors.lastname: Reza
authors.forename: Victor R
authors.initials: VR
authors.lastname: Vasquez
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Coronella
mesh_terms: D000431:Ethanol / Q000378:metabolism*; D005590:Fractional Precipitation / Q000379:methods; D052578:Ionic Liquids / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry* / Q000382:microbiology*; D012639:Seeds / Q000737:chemistry* / Q000382:microbiology*
chemical_list: D052578:Ionic Liquids; D000431:Ethanol