Study of benzene hydrogenation over Ni/Al₂O₃ catalyst in a fixed-bed reactor

Abstract

The performance and activity of (2 wt.%)Ni/γ-Al2O3 catalyst in the hydrogenation of benzene reaction was studied in a high pressure continuous up-flow catalytic fixed bed reactor. Aluminium oxide (Al2O3) was employed as a support material to synthesize (2 wt%)Ni/γ-Al2O3 hydrogenation catalyst using excess solution impregnation method (ESI). Two of the characterizations BET and TGA analysis are carried out in this study. The BET surface area of (2 wt.%)Ni/γ-Al2O3 using BET analysis gives 24.79 m2/g and TGA analysis shows an effective thermal stability of the catalyst. Two parameters of the reactor such as pressure and temperature were varied keeping the liquid hourly space velocity (LHSV) = 2 min-1 fixed to understand the effect on benzene conversion. It was observed that benzene conversion was increased with increasing H2 pressure and after that slightly decreases to 25 bar at temperature 3900C and LHSV = 2 min-1. Further, the benzene conversion is dependent upon temperature and shows a maximum at 3300C and activation energy around 23.24 kJ/mol. The study also shows the effect of LHSV on benzene conversion at, T=3900C and P=25 bar. However, Power Law model of hydrogenation of benzene gives a perfect fit on data and it was found that, the order of H2 is 1 represents a 1st order whereas, the order of benzene is 0.8 (close to 1st order). It was found that (2 wt%)Ni/γ-Al2O3 catalyst showed better performance and activity in the hydrogenation of benzene reaction.