Performance of 1-(3-Sulfopropyl)-3-Methylimidazolium Hydrogen Sulfate as a Catalyst for Hardwood Upgrading into Bio-Based Platform Chemicals

Abstract

The acidic ionic liquid 1-(3-sulfopropyl)-3-methylimidazolium hydrogen sulfate ([C3SO3Hmim]HSO4) was employed as a catalyst for manufacturing polysaccharide-derived products (soluble hemicellulose-derived saccharides, furans, and/or organic acids) from Eucalyptus globulus wood. Operation was performed in aqueous media supplemented with [C3SO3Hmim]HSO4 and methyl isobutyl ketone, following two different processing schemes: one-pot reaction or the solubilization of hemicelluloses by hydrothermal processing followed by the separate manufacture of the target compounds from both hemicellulose-derived saccharides and cellulose. Depending on the operational conditions, the one-pot reaction could be directed to the formation of furfural (at molar conversions up to 92.6%), levulinic acid (at molar conversions up to 45.8%), or mixtures of furfural and levulinic acid (at molar conversions up to 81.3% and 44.8%, respectively). In comparison, after hydrothermal processing, the liquid phase (containing hemicellulose-derived saccharides) yielded furfural at molar conversions near 78%, whereas levulinic acid was produced from the cellulose-enriched, solid phase at molar conversions up to 49.5%.

Evaluation of Acidic Ionic Liquids as Catalysts for Furfural Production from Eucalyptus nitens Wood

“…The best result (FC = 78.12%) was obtained using 1-propylsulfonic-3-methylimidazolium chloride at 140 • C for 180 min. Recently, López et al [41] obtained furfural from hemicellulose hydrolyzates, which were processed with [C3SO 3 Hmim]HSO 4 and MIBK to yield furfural at near 78% molar conversion.…”

Ionic Liquids in Catalysis

“…The first one concerns biomass processing and the synthesis and application of ionic liquids from biorenewable resources. Parajo et al presented an effective (one or two-step) method for the processing of eucalyptus wood towards producing furfural and levulinic acid with the use of acidic ionic liquid (C 3 SO 3 Hmim)HSO 3 as a catalyst [25]. Bengoa et al described the processing of cellulose (obtained from municipal and industrial sewage) into valuable levulinic acid, while also using a Brønsted acidic ionic liquid as a catalyst [26].…”