Performance study of Ni, Co, and Mo catalysts supported on gamma-Al2O3 and HZSM5 in HDS reactions of mixed naphtha

Abstract

Ni/γ-Al2O3, Ni/HZSM5, Co/HZSM5, Mo/HZSM5, and NiMo/γ-Al2O3 catalysts were synthesized by the wetness impregnation technique. Field emission scanning electron microscopy, X-ray diffraction, and nitrogen physisorption methods were used for characterizing the prepared catalysts. The activity of the synthesized catalysts was studied by passing the mixed naphtha and H2 over a fixed bed reactor with sulfiding process prior to HDS reactions at ambient pressure, 285°C, LHSV of 5.8 h−1, and H2/HC volumetric ratio of 94. Ni, Co, and Mo with mass percent of 3.5 wt% were loaded on laboratory-synthesized γ-Al2O3 and purchased HZSM5 supports. For promoted NiMo/γ-Al2O3 catalyst, 3.5 wt% Ni and 17 wt% Mo were impregnated on laboratory synthesized γ-alumina support, similar to the commercial industrial catalyst. Ultimately, the HDS reactions over the synthesized NiMo/γ-Al2O3 decreased the total sulfur content of mixed naphtha from 430 to 25 ppm wt, as a synthesized catalyst with the best reactor performance and acceptable long-term stability.