Abstract:
Biojet fuel is obtained by the hydrodeoxygenation of triglycerides followed by hydrocracking and hydroisomerization reactions of the intermediate long chain hydrocarbons. In our previous studies, the catalysts for the two reactions were Pd/TiO₂ and Pt/HY respectively. In this research. The two catalysts were combined into Pt/HY ͨ ͦ ͬ ͤ -Pd/TiO₂ s ͪ ͤ ll catalysts with different Pd/TiO₂ s ͪ ͤ ll compositions (i.e. 31 %, 36 %, 44 %, and 57 wt%). The catalytic activities of the core-shell catalyst were tested in a continuous flow fixed bed reactor, compared with the pure Pt/HY, Pd/TiO₂ and physical mixture of the two catalysts. XRD, TEM, BET, TPD, TPR. And AAS results showed losing Pt/HY and Pd/TiO₂ catalyst properties. The core-shell catalysts with Pd/TiO₂ s ͪ ͤ ll of 31 %, 36 %, 44 %, and 57 % exhibited 100 % conversion of triglycerides into gasoline, jet, and diesel fuel range products while Pt/HY catalyst exhibited very low conversion of triglycerides with high oxygenate products and Pd/TiO₂ catalyst only converted to diesel range paraffin hydrocarbons compared to those obtained over core-shell catalyst were shorter chain hydrocarbons compared to those obtained from the physical mixing catalyst due to its core-shell mechanism that jatropha oil was first deoxygenated in Pd/TiO₂ s ͪ ͤ ll before further cracked in Pt/HY ͨ ͦ ͬ ͤ. Among all prepared catalysts, the core-shell catalyst with 36 % Pd/TiO₂ s ͪ ͤ ll gave the highest biojet fuel yield of 40 % at TOS of 2 h.
