NiMo/ZSM-23 catalysts for deoxygenation and isomerization of C16-C18 fatty acids to sustainable diesel and jet fuel components

Abstract

A series of Ni-Mo/ZSM-23 catalysts with a different atomic Mo/(Ni + Mo) ratio was prepared by incipient wetness impregnation with a co-solution of salts of Ni and Mo precursors. The formation of NiMoO₄ in the case of oxide catalysts was shown by XRD and Raman spectroscopy. An increase in the molybdenum content in the catalyst composition leads to a decrease in the amount of the NiO phase and an increase in the NiMoO₄ phase. This correlates with changes in the activity of the reduced catalysts during the hydrotreating of a mixture of fatty acids (C₁₆-C₁₈) in a flow reactor at 300 °C, P_H2 = 2.5  MPa, H₂/FAs = 2200  m³/m³ and WHSV = 8.4  h⁻¹. Thus, the highest conversion and iso-alkanes yield were observed in the case of NiMo-0.1 and NiMo-0.25 catalysts. With an increase in the ratio of hydrogen to raw materials to 3150  m³/m³, the highest yield of iso-alkanes is observed on the NiMo-0.4 catalyst.