The Research Of Carbon Reduction Mechanism For Propane Dehydrogenation Catalyst

With the development of global chemical industry,there is a great demand of the chemical product such as polypropylene,acrylonitrile and propylamine.At the same time,the propylene as one of raw materials also increses a lot along with the chemical product.Compared with the traditional naphtha cracking process,propane dehydrogenation（PDH）is a kind of economic and environmental friendly process.At present,there are only 27 sets of propane dehydrogenation production plants in the worldwide and the annual output can reach12.5 million tons.In addition,propane dehydrogenation plants continue to be built and put into operation around the world every year.Therefore,the optimization of propane dehydrogenation process and the decrease of the energy consumption is of great importance.At present,Pt and Cr catalyst system have been achieved industrialization of propane dehydrogenation.PtSn/Al₂O₃ is the best catalyst in the propane dehydrogenation reaction.At present,to enhance the stability of PtSn/Al₂O₃ catalyst is the key point of research.First of all,the thesis studied the effects of the reaction gas composition on the surface of0.5%Pt1.0%Sn/Al₂O₃ catalyst.Effects of different partial pressure of C₃H₈ and H₂ are studied on the performance of catalyst.The best reaction gas proportion are achieved.Under the condition of optimum reaction gas ratio,Ce as co-promoter has been studied for the performance of 0.5%Pt1.0%Sn/Al ₂O₃ catalyst.The stability of the catalyst was improved after loading Ce composition.The optimum loading amount of Ce is 1%.In addition,the regeneration performance is better than 0.5%Pt1.0%Sn/Al₂O₃ catalyst.NH₃-TPD and H₂-TPR characterization show that Ce decreased the performance strong acid and increased the interaction of Pt and Sn.Last but not the least,Ce helps increase the unsaturated coordination of Pt particle,at the same time,the interaction of Sn and Al₂O₃ have been strengthened.