Search

To utilize carbohydrates in lignocellulosic biomass, a fractionation of lignocellulose is crucial. In this study, poplar wood sawdust was treated with a mixture of ionic liquids, 1-butyl-3-methylimidazolium acetate ([Bmim][ OAc]) and 1,3-dimethylimidazolium methyl phosphite ([Dmim][ MeO(H) PO2]), to separate carbohydrate and lignin components from wood. Three types of product were isolated: water-soluble wood ( WSW), water-insoluble wood ( WIW), and wood in ionic liquids ( WIL). At a dissolution temperature of 130°C for 18 h, WSW was found to have high carbohydrate and low lignin contents of 81.0 and 3.5%, respectively, corresponding to a delignification efficiency of 88.9%. WIW isolated under the same condition was found to have 55% of the lignin of native poplar. However, with an increase in the dissolution temperature and the time, the yield of WIL increased due to the increased phosphorylation in both carbohydrate and lignin, forming a mixture of carbohydrate and lignin having phosphorylated ionic functional groups. [ABSTRACT FROM AUTHOR]

Abstract: Decarboxylation of glycerol carbonate (GLC) to produce 2,3-epoxy-1-propanol (glycidol) was conducted using various kinds of ionic liquids (ILs) as catalysts. ILs bearing an anion with medium hydrogen-bond basicity such as and I− exhibited the higher glycidol yields than those having an anion with low or strong hydrogen-bond. FT-IR spectroscopic analysis shows that both GLC and glycidol interact with anions of ILs through their hydroxyl groups. It was possible to improve the yield of glycidol when a zinc salt with a medium Lewis acidity was co-present along with an IL. The yield of glycidol was greatly increased up to 98% when the decarboxylation was conducted in the presence of a high-boiling aprotic solvent. Computational calculations on the mechanism using 1-butyl-3-methylimidazolium nitrate as a catalyst revealed that the first step is the -assisted ring-opening of GLC followed by the ring closure, resulting in the formation of a 3-membered ring intermediate species. [Copyright &y& Elsevier]

Abstract: The solubility of carbon dioxide in room temperature ionic liquids (RTILs), dialkylimidazolium dialkylphosphates, was measured at 313–333K and at pressures close to atmospheric pressure, from which Henry''s law coefficients, standard Gibbs free energy, enthalpy, and entropy changes of solvation were derived. The CO2 solubility in the dialkylimidazolium dialkylphosphate was found to increase with increasing chain length of the alkyl groups on the cation and/or the anion as was similarly found in other RTILs. Among various dialkylimidazolium dialkylphosphates tested, 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][Et2PO4]) and 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][Bu2PO4]) exhibited the comparable or better capability of dissolving CO2 in comparison with that of [BMIM][BF4], but their absorption capacities were still lower than that of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][Tf2N]). [Copyright &y& Elsevier]

CF3CHFCF2OCH2CF3 (1,1,2,3,3,3-hexafluoropropyl--trifluoroethylether), one of the third generation CFC alternatives, was obtained in high yield and selectivity from the hydroalkoxylation reaction of hexafluoropropene with 2,2,2-trifluoroethanol conducted in the presence of a catalytic system consisting of a potassium salt and an ionic liquid, 1-butyl-3-methylimidazolium chloride ([BMIm]Cl). The formation of commonly observed olefinic side products in the hydroalkoxylation catalyzed by potassium salts was greatly reduced by the co-presence of [BMIm]Cl. Theoretical calculations and mechanistic studies suggested that potassium ion is largely responsible for the formation of olefinic side products. [Copyright &y& Elsevier]