Catalytic dehydrogenation of propane on chromia, palladium and platinum supported catalysts

The dehydrogenation of propane to propylene over Cr2O3/Al2O3, Pd/Al2O3 and Pt/SiO2 has been investigated in the temperature range 580–618°C. Runs were performed on propane, alone or in the presence of nitrogen (as a diluent), with complete analysis of the reaction products. The reaction was carried out in a fixed bed reactor at space velocities from 450–800 h−1 which are close to industrial values and at pressures from 0.3 to 1 atm. A set of runs was made over a commercial chromia-alumina catalyst (10% Cr2O3) and over a promoted catalyst prepared in the laboratory by impregnation (16.8% Cr2O3 + 2% K2O). The latter catalyst showed high selectivity and stability even when subjected to continuous cycles of dehydrogenation, regeneration and purging. Of the two noble metal supported catalysts used, reduced Pd/Al2O3 showed higher activity than Pt/SiO2 at 618°C. The former catalyst gave a propylene yield of around 98% at 20% conversion level.