Hydrocracking and hydrodesulfurization of diesel over zeolite beta-containing NiMo supported on activated red mud

Abstract

NiMo nanocatalysts supported on activated red mud with different zeolite beta contents were successfully prepared by impregnation technique. Their hydrocracking and hydrodesulfurization activities were evaluated with two different kinds of diesel feed (iso diesel and heavy diesel) in a fixed bed reactor at ambient pressure and 500 °C. Physico-chemical properties of synthesized samples were characterized using the methods of XRF, XRD, FESEM, BET, FTIR and NH3-TPD. The results indicated that zeolite incorporation resulted in a significant increase in specific surface area (BET result) and acidic strength (TPD result) of nanocatalysts. FESEM analysis confirmed that the particles size of zeolite-containing NiMo/ARM was less than 100 nm and the average size of particles was about 30 nm. Hydrocracking results illustrated that incorporation of zeolite beta improved cracking activity considerably. In addition, NiMo nanocatalyst containing 37.5 wt% of zeolite had the highest yields of desirable products (naphtha, kerosene and diesel) and the highest conversion. Moreover, the flash point and viscosity of the liquid product decreased notably the nanocatalysts with 37.5 wt% and 12.5 wt% of zeolite were able to remove approximately 96% and 72% of the sulfur content of iso diesel and heavy diesel, respectively.