Conversion of mono/di/polysaccharides into furan compounds using 1-alkyl-3-methylimidazolium ionic liquids

authors	Lima, S; Neves, P; Antunes, MM; Pillinger, M; Ignatyev, N; Valente, AA
nationality	International
journal	APPLIED CATALYSIS A-GENERAL
author keywords	Ionic liquids; Saccharides; Acid catalysis; Hydrolysis; Dehydration; Furfural; 5-Hydroxymethyl-2-furaldehyde
keywords	D-FRUCTOSE; DEHYDRATION; BIOMASS; FUELS; WATER; DECOMPOSITION; DISSOLUTION; CHEMICALS; CELLULOSE; CATALYST
abstract	The one-pot hydrolysis/dehydration of mono/di/polysaccharides into furfural (FUR) or 5-hydroxymethyl-2-furaldehyde (HMF) in the presence of an acidic ionic liquid. 1-ethyl-3-methylimidazolium hydrogen sulfate ([EMIM][HSO(4)]), at 100 degrees C, was investigated and the results were compared with those using 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), with or without CrCl(3) or H(2)SO(4). The ionic liquid [EMIM][HSO(4)] is effective in converting xylose and fructose or related polysaccharides into FUR (e.g. from xylose: 84% yield at 6 h) or HMF (e.g. from fructose: 88% yield at 30 min), but not glucose and polymers containing these units, which contrasts to that observed for the [BMIM][Cl]/CrCl(3) system. The latter is quite effective in converting glucose and related disaccharides into HMF, but not the polysaccharides cellulose and starch. For the latter feedstocks, the addition of H(2)SO(4) or [EMIM][HSO(4)] to cellulose/[BMIM][Cl]/CrCl(3) enhances HMF yields, presumably by accelerating the hydrolysis step, although the selectivity of the dehydration of glucose monomers seems rather poor (HMF yield < 13 wt.%). In the case of the xylose to FUR conversion in [EMIM][HSO(4)], two systems involving the reaction and simultaneous separation of the target product were investigated, namely reaction/solvent extraction and reaction/evaporation systems, and for both the ionic liquid could be recovered and reused without a significant drop in FUR yield in recycling runs. (C) 2009 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0926-860X
year published	2009
volume	363
issue	1-2
beginning page	93
ending page	99
digital object identifier (doi)	10.1016/j.apcata.2009.04.049
web of science category	Chemistry, Physical; Environmental Sciences
subject category	Chemistry; Environmental Sciences & Ecology
unique article identifier	WOS:000268512200013