The effect of rare earth element (neodymium) on coke deposition in Pt/γ-Al2O3-Cl catalyst for reforming reaction

Catalytic reforming is a major conversion process in petroleum refinery and petrochemical industries. In this process, naphthenic compounds and straight-chain (normal) paraffins are transformed into the branched-chain (isomers) paraffins and aromatic compounds. With this process, the octane number of naphtha increases by increasing the concentration of branched-chain paraffins and mainly of aromatics. There has been an enormous amount of work over the years involved with understanding the role of the second metal on activity, selectivity and coke deposition, but these findings have rarely been reported about Pt-Nd/γ-Al2O3 catalyst. Rare earth elements play an important role in the modification of some catalysts. There are only a few studies about rare earth influence on some materials like silica, alumina and Beta zeolite. So the influence of neodymium on the catalytic preference of n-heptane over Pt/γ-Al2O3-Cl was studied in this work. We also report activity, selectivity and the deposition rate and amount of coke in the n-heptane reforming process with bimetallic Pt-Nd that compared with Pt-Pb supported on γ-Al2O3 catalysts. The Pt-Nd/γ-Al2O3-Cl catalysts were prepared with different amounts including x:y=0:0.6, 0.06:0.54, 0.2:0.4, 0.3:0.3, 0.4:0.2, 0.54:0.06, 0.6:0 which x is weight percent of Pt and y is weight percent of Nd. The effects of temperature (450-500 °C) and pressure (15-30 atm) also have been compared and discussed. The results indicate that the coke formation on Pt-Nd/γ-Al2O3-Cl catalysts is less than Pt/γ-Al2O3-Cl. The higher amount of activity was observed in Pt-Nd/γ-Al2O3-Cl which is 99.8% at 15 atm and 500 °C [1-3].