Study On Synthesis And Process Conditions Of Long Chain Alkane Dehydrogenation Catalyst

In recent years,the coal chemical has developed rapidly in China.As one of the main products of Fischer Tropsch synthesis,direct alkanes provide sufficient raw materials for the production of long chain olefin with high added value,which brings a new opportunity for the study of the dehydrogenation process of long chain alkanes.Currently,long chain alkane dehydrogenation catalysts used in industry still have low conversion rate and short single life in production process.In order to select the long chain alkane dehydrogenation catalyst with high activity and high anti inactivation ability,the catalyst was prepared by different alumina carrier,and the performance of the catalyst was tested by standard evaluation method,and the characterization analysis of XRD,BET,TPR,TG and XRF was carried out.The characterization analysis shows that the microporous structure of the carrier is reduced,the mesoporous and large pores are increased,which is more suitable for the dehydrogenation of long chain alkanes.In the other way,because of the decrease of surface acidity,the carrier reduces the high temperature carbon deposition of the catalyst,and enhances the deactivation ability of the catalyst.The long period test of the catalyst for 260 h shows that the conversion,selectivity and inactivation ability of the catalyst have reached the requirements of industrial application.Optimize of components of the above carrier.The experiment showed that the catalyst had better catalytic activity and life when the load of Pt,promoter A and promoter B were 0.3 wt%,0.54 wt%and 0.5 wt%,respectively.The interaction between each component and the interaction between the components and the carrier reached the best state.Compared with the industrial catalyst,the conversion rate increased from 9.58%to 12.50%,the inactivation rate decreased from 25.16%to 20.02%,and the activity and the inactivation ability had a greater increase.In order to further make laboratory achievements applied to production,we explored the best process conditions of new catalysts through experiments.The experimental results show that the optimum technological conditions of the new catalyst are the reaction temperature 460 ?,the reaction pressure 0.1?0.15 MPa(g),the hydrogen/oil ratio 600 and the space velocity 15?20 h-1.