Preparation of NiMoRe/HZSM-5 Catalyst for Hydrodeoxygenation of Fatty Acid Methyl Ester

A 5 kg NiMoRe/HZSM-5 catalyst was prepared by impregnation method, and the physicochemical properties of the catalyst were analyzed using characterization techniques such as X-ray diffraction(XRD), scanning electron microscopy(SEM), and inductively coupled plasma optical emission spectrometry(ICP-OES). The optimal conditions for the catalyst in the hydrogenation deoxygenation reaction of stearic acid methyl ester were explored. The research results showed that, compared to three commercial catalysts, the metal nickel in NiMoRe/HZSM-5 had smaller and more uniformly dispersed particles, a larger BET specific surface area(S_BET) of 239.1 m²/g, and exhibited better catalytic activity. Under the optimal reaction conditions of 260 ℃, catalyst dosage of 0.3 g, reaction time of 4 hours, and initial H₂ pressure of 3 MPa, both the raw material conversion rate and alkane selectivity were 100%. The catalyst demonstrated good stability, with a high raw material conversion rate of 96.1% even after the 5th cycle, and the ratio of hydrogenation deoxygenation(HDO) reaction to decarboxylation/decarbonylation(DCO) reaction decreased from 1.2 to 0.56. After scaling up the hydrogenation deoxygenation reaction of fatty acid methyl ester under solvent-free conditions using the NiMoRe/HZSM-5 catalyst, a pilot-scale evaluation was conducted on 25 kg of fatty acid methyl ester in a 2.8 L fixed bed reactor. After 15 cycles, the fatty acid methyl ester achieved a conversion rate of 98%.