Study On Catalysts For Dehydration Of2,3-Butanediol To Methyl Ethyl Ketone And Process Optimization

Methyl Ethyl Ketone (MEK) is an excellent organic solvent which is widely used. There are many kinds of production methods of MEK.But pertro chemical resources are often used as raw materials in industry. The raw materials are non-renewable and the ways of operation is difficult. In this situation, it is necessary to find a efficient way to product MEK with using renewable raw materials.The biological fermentation route of2,3-butanediol intermediate is used as raw material, methyl ethyl ketone is high added value products. The modified molecular sieve is used as catalyst, and optimize the best process conditions.(1) Through the experiments, the reaction result is the best for the modified HZSM-5with silica to alumina ratio38. HZSM-5with SO42-MxOy loaded on can effectively increase the2,3-butanediol conversion and selectivity of methyl ethyl ketone, especially SO42-CuO, SO42-CuO, SO42-SnO2and SO42-Al2O3. Sulphate is directly loaded on HZSM5molecular sieve, CuSO4, MnSO4, ZnSO4can effectively increase the activity of catalyst. Optimization of catalyst modification conditions is10min of dipping time at room temperature.(2) Optimization process conditions for reaction is emperature of320℃, raw material concentration of50wt%, carrier gas N2flow rate of7ml/min, reaction velocity of1.6h-1and the conversion of2,3-butanediol is99.1%, the yield of methyl ethyl ketone is83.0%. And at the process conditions, fresh CuSO4(16%)/HZSM-5is still maintaining high catalytic activity after used240h, the yield of methyl ethyl ketone is73%. In240-250h, catalyst activity lost, but catalyst activity recover after calcination.(3) At the optimal process conditions, CuSO4(16%)/HZSM-5is used as catalyst, biomass2,3-butanediol is used as raw material.2,3-butanediol conversion reach to99.4%, the yield of methyl ethyl ketone reach to84.3%, catalyst performance is still good after used15h.(4) In order to improve the reactivity of the catalyst, two-component modified is used. Experments on three kinds of load mass concentration for2,3-butanediol dehydration, The results show that the ZnSO4modified with0.5%load,2,3-butanediol conversion is100%, the yield of methyl ethyl ketone is78.1%.