CONTINUOUS HYDROTREATING PROCESS OF PALM FATTY ACID DISTILLATE (PFAD) OVER BIMETALLIC NiCu/HZSM-5 CATALYST FOR BIO JET FUEL PRODUCTION

Abstract

This research investigated bimetallic NiCu/HZSM-5 catalyst for the production of bio jet fuel via hydrotreating process. The catalysts with different Ni and Cu ratio were characterized by XRD, NH3-TPD, H2-TPR, SEM-EDX and N2-physisorption techniques. Palm fatty acid distillate (PFAD), nonedible by-product from palm oil refining process, was employed as a low-cost feedstock. For catalyst screening, the reaction was performed in an autoclave reactor under batch operation with operating temperature of 375°C, initial H2 pressure of 50 bars and reaction time of 3 h. The results showed that doping Cu could enhance deoxygenation activity while carbon formation was found to be suppressed. 12.5 wt.% Ni and 2.5wt.%Cu doping on HZSM-5 catalyst was found as a suitable catalyst to obtain a high conversion of PFAD (94.8%) with the lowest carbon deposition on the catalyst (approx. 5 wt.%). The selectivity of green fuel is gasoline 14.9%, jet fuel 45.0% and diesel 40.1%. For continuous operation, 12.5 wt.% Ni and 2.5 wt.% Cu were loaded on commercial pellet-type HZSM-5 catalyst. At operating temperature of 400°C, H2 pressure of 40 bar and H2/oil molar ratio of 100, the most suitable LHSV of 2 h-1 condition was found to achieve high conversion (90.1%) with a stable operation. The conversion gradually dropped over 80 h of the operating time (approx. 65.0% conversion) and then suddenly drops to 36.5% conversion at 103 h.