Study On Hydrogenation Of Methyl Acetate To Ethanol Over Copper-based Catalyst

With the increasing of oil imports and environmental protection requirements,fuel ethanol is a clean alternative energy source with the wide applications in China.Hydrogenation of methyl acetate(MA)to ethanol is a new ethanol production route and has attracted much attention of researchersIn this thesis,the thermodynamic simulation of the reaction was firstly carried out,and the regularity of the important process conditions such as temperature,pressure and hydrogen-ester ratio of the reaction was obtained.Through the study on the influence of different kinds of the promoters,the process conditions and the catalyst deactivation on the catalytic performance and the reaction,combined dynamic and static characterization,the following results were obtained:(1)Hydrogenation of methyl acetate is a low temperature favorable exothermic reaction and also a molecule decrease reaction,the lower feed temperature,the higher reaction pressure and the higher H2/MA molar ratio are favorable for the reaction;(2)The effects of the promoters Ba,Ca and Ag had been investigated.The promoter Ba could increase the ethanol selectivity of the F021 catalyst,while the other promoters could decrease both the MA conversion and ethanol selectivity of the catalyst;(3)Both thermodynamic simulation and experimental evaluation show that the process conditions such as temperature,pressure and hydrogen-ester ratio have a significant influence on the hydrogenation of methyl acetate to ethanol.High temperature will not only reduce the conversion of methyl acetate,but also significantly increase the by-product ethyl acetate;(4)On the F021 catalyst,the reduction of the catalyst has a significant effect on the hydrogenation performance of methyl acetate.When the reduction temperature is 190? and the reaction temperature is 220?,the catalyst has an optimized reaction performance of hydrogenation of methyl acetate to ethanol;(5)when the gas hourly space velocity keeps constant,the catalytic activity of the catalyst and the selectivity of the target product are increasing with the reaction pressure and hydrogen ester ratio.The main reason of the catalyst deactivation was investigated by a method of rapid increasing temperature experiment.The catalyst had a methyl acetate conversion of 95%and an ethanol selectivity of 94%at a reaction temperature of 220?.When the reaction temperature is raised to 350?,the by-products increase sharply,the catalytic performance of the catalyst decreases significantly,the methyl acetate conversion is 69%,and the ethanol selectivity is 65%.The temperature-programmed oxidation,thermogravimetry,X-ray diffraction,temperature-programmed desorption had been carried out on the catalyst after high-temperature treatment.The results show that the sintering of the active component copper and carbon deposition are the main reasons for the catalyst deactivation.