Propane Dehydrogenation Catalysts And Reaction Conditions For Research

The experiment by ZSM-5 as the carrier, with an equal volume of continuous impregnation were prepared by Pt/ZSM-5, Pt-Sn/ZSM-5, Pt-Sn-Na/ZSM-5, Pt-Sn-Na/ Al2O3, Pt-Sn-Zn/ZSM-5, Pt-Sn-La/ZSM-5, Pt-Sn-Ce/ZSM-5 catalyst such conduct experimental study catalytic dehydrogenation of propane, the same time with a series of characterization methods for in-depth analysis. Pick out a excellent Characterization of catalyst, a detailed analysis in order to develop a kind of ZSM-5 zeolite catalyst carrier, it may be applied in an industrial propane dehydrogenation.1. Pt/ZSM-5 catalyst, the conversion rate reached 71.51%, but basically generate CH4 and C2H4, the selectivity and yield is only 16.11% and 8.30% lower.Pt-Sn/ZSM-5, Pt-Sn-Zn/ZSM-5, Pt-Sn-La/ZSM-5 and Pt-Sn-Ce/ZSM-5 catalysts, but their selectivity is no more than 40%, their effect is not ideal.Pt-Sn-Na/ZSM-5 catalyst, although there is a little low, but selectivity has reached more than 90%, the yield is close to 20%, have the better production analysis of the significance. At the same time, we think to the preparation of catalyst such as volume continuous immersion method is the best preparation method, the process as follows:the catalyst in flowing hydrogen (5mL/ min) at 500℃ under reducing 5h, then bubbled through the reaction tube propane and hydrogen gas, propane flow rate of 100mL/min, hydrogen flow rate of 5mL/min. the reaction temperature was 590℃, WHSV reaction was 1400h-1. The results show that Sn and Na suitable adjuvants can promote dehydrogenation ability Pt/ZSM-5 catalysts, using TPR, DSC and some way to various properties of the catalyst, also studied the carbon issues further exploration.2. Na optimum loading is 1.0%. Na appropriate and not only in the acidity, reducing side effects, still can make Pt dispersed. Excess Na weaken the force between Sn and Pt, reduce the effective component of Sn, Sn have the oxidation state of zero valence state of Pt with Sn component Pt-Sn alloy is formed.3. Not only the performance of the catalyst and the active substance, associated auxiliaries, and have a great relationship and experimental factors. The experiments were performed using Pt-Sn-Na/ZSM-5 catalysts, get it under the ideal state of the optimal operating factors:Under a hydrogen atmosphere, the catalyst mass 2.0g, pressure 0.1 MPa, temperature 590℃, n (H2):n (hydrocarbon)=0.05,WHSV=1400h-1.