Cellulosic conversion in ionic liquids (ILs): Effects of H2O/cellulose molar ratios, temperatures, times, and different ILs on the production of monosaccharides and 5-hydroxymethylfurfural (HMF)

The effects of several critical factors including H2O/cellulose molar ratios, dissolution temperatures (Tdis), dissolution times (tdis), reaction temperatures (Trxn), reaction times (trxn), and types of ionic liquids (IL) were investigated for cellulosic conversion. We optimized the reaction conditions as: H2O/cellulose = 10/1, Tdis = 120 °C, tdis = 0.5 h, Trxn = 120 °C, trxn = 3 h for 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl)-based system, and the maximum yield of 5-hydroxymethylfurfural (HMF) up to 21% could be achieved without adding extra catalysts. Another pyridinium-typed IL, [Epyr]Cl, was also used in the cellulosic conversion, and the results showed a high selectivity toward monosaccharides. The information obtained in this study will benefit many biofuel-related applications.