Production of renewable hydrocarbon fuel from hydrotreatment of soybean oil with Ni-Mo/zeolite HY catalysts

This study investigates the hydrotreatment of soybean oil toward renewable hydrocarbon fuels over zeolite HY-supported Ni–Mo bimetallic catalysts (Ni–Mo/Y). Catalysts with systematically varied Ni/Mo ratios were synthesized via the incipient wetness impregnation method and evaluated in a batch/semi-batch reactor over 6 h, using decalin as a diluent. Among the catalysts tested, Ni–Mo(R)/Y catalysts with a Ni/Mo mass ratio of 4 exhibited superior deoxygenation efficiency in soybean oil. Under reaction conditions of 350 °C and 44 bar H2, the 32Ni–8Mo(R)/Y catalyst achieved nearly complete removal of oxygen from soybean oil molecules. The resulting alkane fuel exhibited a low acid value of 0.06 mg KOH/g oil and an iodine value below 1 g I/100 g oil, confirming the near-absence of unsaturated compounds (alkenes and alkynes). The yield of middle-distillate-range hydrocarbons (>C12) reached approximately 60.7–62.9%. Deactivation of catalysts could be attributable to the blockage of active sites by adsorbed reactants and hydrocarbon products, leading to reduced surface acidity. The spent catalyst could be effectively regenerated for producing hydrotreated soybean oil with an acid value approximately 0.10 mg KOH/g oil. Overall, these findings highlight the synergistic role of Ni–Mo bimetallic composition and acidic zeolite support in governing deoxygenation activity and product selectivity, providing critical insights for the rational design of high-performance catalysts for sustainable fuel production.