Abstract

Investigation of Cs, K and La on cyclohexane and n-hexane aromatization over Pt/Al2O3 catalyst

Author(s): A.H.Samia, M.S.Mohammed, S.A.Ahmed

Catalytic reforming accounts for a large share of the world’s gasoline production, it’s the most important source of aromatics for the petrochemical industry. In addition, reforming of the hydrocarbon on the dual function catalysts has been found to form fundamentally different products in hydrogen diluents. While catalytic reforming is a complex process involving reactions of a large number of hydrocarbons, the understanding of this process will result from studies of the reactions of the individual hydrocarbons present in the petroleum naphtha. In this paper, a series of catalysts on the basis of pt/Al2O3 with and without additives (Cs, K and La) have been prepared and investigated. The content of the additives were varied in the range of 0.25-3.0 wt%, and the weight of pt was constant at 0.25 wt%. Physico-chemical characteristics of the prepared samples were determined by surface area (SBET), Fourier transforminfrared (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), hydrogen-temperature programmed reduction (H2-TPR) and CO2 – Temperature programmed desorption (CO2 – TPD). The activity of the catalysts in cyclohexane dehydrogenation and n-hexane dehydrocyclization was studied at the temperature range of 300-450oCat atmospheric pressure. The results showed that the cyclohexane dehydrogenation activity is actually an intrinsic property of clean platinum. The presence of La2O3 in the pt/Al2O3 catalyst promotes aromatization of n-hexane. Thusmodification of the pt/Al2O3catalyst by La2O3 resulted in a more active and selective reforming catalyst.