Catalytic Dehydrogenation of Propane: Oxidative and Non-Oxidative Dehydrogenation of Propane
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The dehydrogenation of propane has a great interest, due to a global growing demand in propene. This reaction needs a catalyst, high temperature and low propane partial pressure. During this work, platinum hydrotalcite-supported was used as catalyst. First, three different kinds of support were tested: the hydrotalcite 30 (30% MgO, 70% Al2O3), the hydrotalcite 63 and the hydrotalcite 70. The catalysts were prepared with 1 or 2 % mass platinum, by a kind of colloid method. They were characterized by BET, XRD, and chemisorption, and activity tests were performed. The catalytic tests were performed in a fix bed reactor in a temperature range from 350 °C to 650 °C. The propane conversion and selectivity were not really different between the three supports. For example, the selectivity to propene reached a maximum between 50 % and of 55 % at 550 °C for all the catalysts. Then, the catalyst HT 63 with 1 % Pt was selected for further experiments. The feed gas composition was varied, to see the influence of the ratio Propane/Oxygen/Hydrogen. Some experiments involved oxidative dehydrogenation of propane, whereas some others were non-oxidative dehydrogenation of propane. The propane conversion was better when the reaction took place simultaneous with oxidative reactions. The system is complex, but some feed gas compositions favor the conversion of propane and the selectivity of propane to propylene. The influence of pressure on the reaction was also investigated. Oxidative dehydrogenation of propane was studied at low (1.1 bar) and high pressure (above 3 bar). When the pressure in the reactor during the experiment was above 2 bar, the propane conversion, the propane selectivity to propene and the propene yield are improved.