| Summary: | The use of catalysts during pyrolysis offers a viable alternative for converting fuel oil blended stock (FOBS) into marketable products in the future. However, as FOBS is commonly found in complex compounds, a highly efficient catalyst is necessary to break down the bonds of these compounds. This study explores the use of a bimetallic catalyst, specifically nickel-molybdate (Ni-Mo), supported on hydrogen zeolite socony mobil-5 (HZSM-5) with a silica/alumina ratio of 30. The goal is to convert FOBS into a valuable carbon-based product, resulting in higher production of desirable liquid products while potentially reducing the formation of gas and solid residues. HZSM-5 is commonly employed to facilitate the conversion of complex hydrocarbon structures into simpler hydrocarbons. Meanwhile, Ni and Mo play a role in deoxygenation, which is expected to break down the complicated structure of FOBS compounds. The catalyst was synthesized and segmented into three phases. Phase 1 involved the use of parent catalysts (HZSM-5, Ni, and Mo). Phase 2 involved the use of mono-metallic catalysts, specifically Ni/ZSM5 and Mo/ZSM5, with three different weight percentages: 1%, 3%, and 5%. Phase 3 involved the utilization of a bimetallic catalyst referred to as Ni-Mo/ZSM5 with three different weight percentages: 2Ni-3Mo/ZSM5, 2.5Ni-2.5Mo/ZSM5, and 3Ni-2Mo/ZSM5. Impregnation was used to prepare the catalysts for Phases 2 and 3. The catalysts were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmet-Teller, and scanning electron microscopy. The FOBS was analyzed using gas chromatography-mass spectroscopy, a carbon-hydrogen-nitrogen-sulphur analyzer, kinematic viscosity, and thermogravimetric analysis prior to pyrolysis. The catalytic pyrolysis test was conducted in phases at a temperature of 500 °C for a duration of 60 min. The catalyst-to-feedstock ratios employed were 1:5, 1:10, and 1:15. The findings revealed that the 2Ni-3Mo/ZSM5 catalyst achieved the maximum conversion rate of FOBS and yield of liquid products of 82.25% and 72.92%, respectively, at a ratio of 1:15. The 2Ni-3Mo/ZSM5 catalyst was the main focus of a comprehensive optimization study. The study involved manipulating independent variables to cover a temperature range of 400-600 °C, reaction duration of 60-90 min, and catalyst mass of 0.5-1.5 g. This thorough analysis achieved a maximum conversion level of FOBS at 88.67% and a liquid product yield of 83.33% at the critical point.
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