Microwave heating and hydrolysis of rubber wood biomass in ionic liquids

BACKGROUNDBiomass from rubber wood has been gaining interest due to its availability and relative economic value. However it is difficult to separate the biomass using common solvents due to its complicated structure. The recent application of ionic liquids as reaction solvents has offered a new platform for its efficient utilization. The dissolution of biomass in ionic liquid via microwave has been investigated to reduce the dissolution time. RESULTSThe pretreatment involves dissolving the biomass in various ionic liquids under domestic microwave radiation. The dissolution rate is dependent on the type of ionic liquid and biomass was found to be easily dissolved in acetate based imidazolium ionic liquid. The highest (up to 85%) substantial dissolution of rubber biomass was reached in 1-ethyl-3-methylimidazolium acetate [C(2)mim][OAc] and 1-butyl-3-methylimidazolium acetate [C(4)mim][OAc]. Furthermore, the amount of glucose resulting from pretreatment with [C(2)mim] [OAc] and [C(4)mim][OAc] was also higher than that from pretreatment with cloride anion. This is due to changes in physico chemical properties such as decreasing crystallinity in biomass as confirmed by XRD, TGA and FTIR analyses. CONCLUSIONAnion acetate based imidazolium ionic liquid was discovered to be a good solvent for the dissolution of rubber biomass under microwave irradiation for converting cellulose to glucose. (c) 2014 Society of Chemical Industry