Researches On Cu-Zn-Al Catalyst Of Catalytic Hydrogenation Of Methyl Acetate

There are a lot of methyl acetate by-product in the production process of PVA, so that our country is facing the current situation of methyl acetate overcapacity.Using methyl acetate hydrogenation reaction of ethanol technology can not only improve the status quo, but also the ethanol product is widely used in the field of organic synthesis, food, vehicle fuel, military, medicine, etc, can effectively expand the development of downstream industry chain with methyl acetate, improving environmental pressures, and promote economic development.The research of ester hydrogenation catalyst is receiving increasing attention at home and abroad, although the catalytic hydrogenation process has been industrialized, the traditional Cu-based catalysts used its anti-toxic, mechanical strength, thermal stability and other properties with poor performance, Therefore the core of the technology is the development of efficient catalysts. This paper studies the influence of different components, preparation parameters and reaction conditions for the reactivity of hydrogenation of methyl acetate to ethanol, and optimize the process conditions on the optimum catalyst.Research the reaction mechanism, reaction thermodynamics and dynamics of hydrogenation of methyl acetate, Using coprecipitation preparate catalyst samples of different content of Cu, ratio of Zn/Al and content of additive Ba, and make them activity evaluation. Use the characterization methods of XRD, TPR, BET, SEM, etc to characterize catalysts, and correlate to the effects of activity evaluation. We can know that, more appropriate pore volume, pore size and large surface area to improve the catalytic activity beneficial, when 1:2:2:0.05 of Cu/Zn/A/Ba molar ratio, 1.5mol/L of solution concentration, 7.5 of PH, 500 ℃ of calcination temperature, 7h of calainating time, the catalytic activity is excellent.We can determine the main factors that influence the reaction process is the reaction pressure, reaction temperature, liquid hourly space velocity, ratio of hydrogen and ester, when combined with reaction thermodynamics and dynamics. By evaluating the activity of excellent catalyst,and analysis the factors of hydrogenation with response surface methodology of Design-Expert software. We can determine the optimal reaction conditions are as follows: 229℃ of reaction temperature, 3.0MPa of reaction pressure, 35 of ratio of hydrogen and ester, 1.3h-1 of LHSV. The conversion of methyl acetate and selectivity of ethanol was 98.49% and 98.07% with the excellent reaction conditions, and the catalyst may be continuous and stable operation 1320 h when conversion of not less than 95%.