Abstract:
The hydrogen production by autothermal system of iso-octane over NiCe/Al₂O₃ and NiCr/Al₂O₃ prepared by a co-impregnation method has been investigated under various process conditions. The effects of steam/carbon ratio, oxygen/carbon ratio and reaction temperature were studies on both catalysts. The catalysts were characterized by surface area measurement, SEM, XRD and temperature programmed reduction. The conversions of iso-octane are inhibited when the concentration of steam and oxygen increased. For the NiCe/Al₂O₃ catalyst, it was observed that the H₂/CO ratio of the products was substantially dependent on the steam/carbon ratio upon which increasing the concentration of steam increased such dependence. In contrast. The H₂/CO ratios were slightly effected by increasing oxygen concentrations. For the reactions carried on NiCr/Al₂O₃ both of steam/carbon and oxygen/carbon ratios have strong effects on the H₂/CO ratio. It was observed that the optimum O₂/C ratio and H₂O/C ratio are 0.5 and 2, respectively. Ce and Cr would be excellent promoters of steam reforming catalyst with autothermal system because not only they promote the autothermal reaction but also prevent and reduce the coke formation.
