Catalytic Conversion Of Cellulose To Methyl Lactate And Methyl Levulinate By Paired Metal Chlorides

Currently, fossil resource shortage, environment pollution and energy crisis drive us to look for new renewable carbon sources. Developing methods to convert the abundant renewable biomass resources to useful fundamental chemicals has attracted increasingly attention of people worldwidly. Cellulose as one of the most abundant biomass is more high-profile. Cellulose can be converted into varieties of platform chemicals, such as lactic acid, methyl lactate, levulinic acid, methyl levulinate and so on. These compounds have wide applications in the industries of materials, fuels and chemicals.In our work, a type of new catalysts is designed to convert cellulose into methyl lactate and methyl levulinate in methanol. The conditions are easy to control. We have not seen similar report in this area.As the starting of the work, microcrystal cellulose was selected as the reactant. By combining Sb Cl3 with other metal chlorides as catalys t systems, SbCl₃-AlCl₃·6H₂O was found highly active in converting cellulose to target products.The SbCl₃-AlCl₃·6H₂O catalyst was investigated in detail to optimize the reaction temperature, reaction time, relative catalyst amount, cellulose amount relativ e to the catalyst amount and the amount of methanol. The results of the investigation show that when methanol:cellulose=20:1 and Sb Cl3 to Al Cl3·6H2O mol ratio=1:1,a highest methyl lactate yield of 16.7% and a highest methyl levulinate yield of 7.8% were obtained at 200? within 6 h of reaction.As an extention of the investigation, bagasse was investigated as reactant toprepare methyl lactate and methyl levulinate in the presence of SbCl₃-AlCl₃·6H₂O. The influences of the reaction temperature, reaction time, relative catalyst amount, bagasse amount relative to the catalyst amount and the amount of methanol on the yields of methyl lactate and methyl levulinate were investigated. It was found that the performance of SbCl₃-AlCl₃·6H₂O in the reactions of bagasse is similar to that in the reactions of microcrystal cellulose. The results of the investigation show that when methanol:cellulose=20:1 and Sb Cl3 to Al Cl3·6H2O mol ratio=1:1,a highest methyl lactate yield of 7.5% and a highest methyl levulinate yield of 11.5% were obtained at 200? within 6 h of reaction.