Hydroprocessing of palm oil using Rh/HZSM‐5 for the production of biojet fuel in a fixed bed reactor

Abstract

AbstractThe hydroprocessing of palm oil was performed in a continuous fixed bed reactor to produce biojet fuel. Rh/HZSM‐5 was used as catalyst and was characterized by N2 adsorption‐desorption, x‐ray diffraction (XRD), Scanning electron microscopy (SEM), NH3‐temperature programmed desorption (NH3‐TPD), and H2‐temperature programmed reduction (H2‐TPR). The effect of operating parameters including reaction temperature, molar ratio, and solvent on the yield of biojet and biodiesel was investigated. The catalyst deactivated rapidly in the solvent‐free system due to carbon deposition. The application of 30% heptane in the feed maintained the conversion of palm oil above 90% for 8 hours. At 330°C, the yield of liquid fuel product was slightly less than that obtained at 300°C as more gaseous product was formed. The H2‐to‐oil molar ratio of 158 at 300°C was insufficient to maintain the reaction at high conversion. At 300°C and a H2‐to‐oil molar ratio of 316, the system was stable for the entire experimental period of 8 hours providing the biojet yield and selectivity of 15.3% and 28.5%, respectively. Although, this system was operated at a relatively low temperature for hydroprocessing, the productivity parameter of 0.60 kg product/Kg cat‐h was significantly higher compared to the data provided in the literature.