Hydrolysis of Cellulose by Using Catalytic Amounts of FeCl2 in Ionic Liquids

Microcrystalline cellulose (MCC) is hydrolyzed to an appreciable extent (70 %) by using 1-(4-sulfonic acid) butyl 3-methylimid azolium hydrogen sulfate (IL-1) as effective catalyst Valuable chemicals such as 5 hydroxymethyl furfural (HMF) and furfural, are obtained in relatively high yields (15% and 7%, respectively) Interestingly the introduction of FeCl2 as catalyst into IL-1 further enhances the catalytic activity as proved by the higher, conversion of MCC (84%) and higher yields of HMF and furfural (34% and 19%, respectively) under the same experimental; conditions although small amounts of levulinic acid (LA) and total reducing sugars (TRS) were also found The hydrolysis of MCC scarcely proceeded, or showed a lower efficiency in the absence of catalyst (4%) or with Al2O3 (7%), inorganic acids (<= 65%) or several other ionic liquids (<= 24%) as catalyst Dimers of furan compounds were detected as the main by-products as analyzed by HPLC MS from the mass spectrometry analysis, the components of the gas-phase products were determined to be methane ethane, CO CO2, and H-2 A mechanism to explain the high activity of FeCl2 in the IL-1 system is proposed Recycling of the IL 1 catalyst showed an almost constant activity during five successive trials The simple and effective catalyst system may prove valuable in facilitating the energy-efficient and cost-effective conversion of biomass into biofuels and platform chemicals