Preparation of Pt/Al2O3-Cl Catalyst and Investigation of Operating Variables Effects on Isomerization Reaction

A high chlorinated alumina catalyst obtained by treating Pt/γ-Al2O3 (0.25 wt. % Pt) samples with two mixtures of CCl4/N2 and CCl4/N2/H2 was tested for the hydroisomerization of C6 alkane. The conversion of n-hexane feed was diluted with hydrogen performed with different H2/HC ratios at various temperatures, liquid hourly space velocities (LHSVs) and 3MPa total pressure. The catalyst introduced in the reactor displayed a fairly high initial activity, but conversion slowly declined with time on stream. Adding CCl4 to the hexane feed could not improve the stability with time on stream. The effects of temperature on conversion and isomer selectivity were studied at various H2/HC ratios and LHSVs. Superior conversion and selectivity were found for the catalyst at 160 ˚C and 120 ˚C at LHSV 1.2 h-1. Furthermore, effects of LHSV and low temperature were studied on conversion and product octane number derived from hexane isomerization, respectively. The highest octane number was observed at the low space velocity (1.2 h-1).