Diesel hydrocracking and hydrodesulfurization with activated red mud-supported and fluorine-containing NiW nanocatalysts

Abstract

The effects of red mud utilization as support and fluorine promoter incorporation on the physicochemical properties and hydrocracking and hydrodesulfurization activities of a series of NiW catalysts, called NiW/F-ARM, were studied by diesel as feed. The catalytic performances of NiW/F-ARM were investigated in a fixed-bed reactor at 500 °C and atmospheric pressure. The physicochemical characteristics of catalysts prepared using impregnation were evaluated by XRD, FESEM, BET, FTIR, NH3-TPD and H2-TPR analysis. The obtained data confirmed fluorine addition resulted in a remarkable enhancement in acidity (NH3-TPD result) and reducibility (H2-TPR result) and a decrease in particle size and the number of agglomerates (FESEM result) of samples. It was found that the fluorinated catalysts owned effective activity for hydroprocessing reactions. The catalysts presented appropriate hydrocracking and hydrodesulfurization performances by increasing clean transportation fuels. Fluorine significantly influenced the cracking and hydrodesulfurization activities of catalysts, but the optimum amount of fluorine was needed to be added. The maximum hydrocracking performance was achieved by catalyst consisting of 2.2 wt.% fluorine in heavy diesel conversion. The highest hydrodesulfurization activity varied with the type of feedstock and the catalysts contained 2.2 and 0.8 wt.% of fluorine shown the best performance for ISOdiesel and heavy diesel, respectively.