LAUSR

Abstract The removal of sulfur compounds from petroleum is increasingly important because sulfur compounds poison catalysts (i.e. reduce the activity of the catalysts in oil refinery processes) and are a source of environmental pollution. On the other side, waste rubber tires contribute to environmental pollution. Here, the motive is the utilization of activated carbon (AC) from the waste tires as a support for bimetallic catalysts. Therefore, NiMo catalysts supported on waste tire-derived AC were prepared through an excessive wetness co-impregnation method and subjected to calcination at temperatures of 100, 200, 300 and 400 °C for hydrodesulfurization (HDS). A surface area analyzer, Fourier-transform infrared spectroscope, scanning electron microscope, and Raman spectroscope were used to characterize the prepared catalysts. The HDS reactions with the prepared catalysts were performed in a high-pressure reactor using a model fuel containing 1000 ppm dibenzothiophene at different reaction times. The results showed that the catalyst that is calcined at 300 °C (i.e. NiMo/AC300) is the most active for HDS as compared to the catalysts calcined at other temperatures (i.e. 100, 200 and 400 °C). This catalyst (i.e. NiMo/AC300) has a surface area of 352 m2/g, a 6 nm average pore diameter, a total acidity of 0.26 mmol ammonia/g and exhibits a moderate activation energy for NH3 desorption (i.e. Ea = 102 kJ/mol). The developed catalysts show promising results with the advantage of having a dual benefit – eliminating waste tire disposal problem and producing valuable supports for HDS catalysts to yield sulfur-free fuels.