Kinetic Study of Hydrogenation of Fatty Acid Methyl Ester into Fatty Alcohol over Rhenium–Niobia and Rhenium–Alumina Catalysts

Fatty alcohols can be generated by hydrogenating fatty acid methyl ester (FAME) using a heterogeneous catalyst. Among diverse alternatives, precious metal-based catalysts such as Re/Nb₂O₅ and Re/Al₂O₃ have exhibited superior performance. However, the kinetic study of hydrogenation FAME employing a Rhenium-based catalyst (Re) has not been investigated. Notably, kinetic studies are crucial for performance improvement and reactor design. As a result, the kinetics of the FAME hydrogenation process over these catalysts were studied and modeled comprehensively. The results demonstrate that the reaction with the Re/Nb₂O₅ catalyst has an order of 0.77 to FAME and 1.48 to hydrogen gas, with an Arrhenius constant of 18.55 bar^−1.48 M^0.23 min⁻¹ and an activation energy of 64.44 kJ mol⁻¹. The Re/Al₂O₃ catalyst has an order of 0.67 to FAME and 1.15 to hydrogen, with an Arrhenius constant of 1057.89 bar^−1.15 M^0.33 min⁻¹ and an activation energy of 78.32 kJ mol⁻¹. The Re/Al₂O₃ catalyst is more sensitive to temperature changes than the Re/Nb₂O₅ catalyst. Meanwhile, the Re/Nb₂O₅ catalyst is more sensitive to pressure changes than the Re/Al₂O₃ catalyst.