One-step hydrotreatment of inedible oil for production the second-generation biofuel over Pt-Sn/SAPO-11 catalyst

Abstract The direct conversion of inedible oil to produce the second-generation of biofuel is a promising technology. In this study, Pt/SAPO-11 catalyst was synthesized, and it was further modified by Sn. Two typical inedible oils (Jatropha oil and waste lard oil) were used as feedstocks. The liquid yield, deoxygenation rate, selectivity of alkanes, and selectivity of iso-alkanes were studied. It is shown that the selectivity of alkanes and iso-alkanes increase simultaneously over Pt-Sn/SAPO-11. The selectivity of C8-C16 alkanes and iso-alkanes from Jatropha oil is 69.82% and 39.30%. In the case of waste lard oil, there were 64.42% selectivity of C15-C18 alkanes and 50.05% selectivity of C15-C18 iso-alkanes. Pt-Sn/SAPO-11 catalyst remains a higher hydrotreating activity and stability during the 72 h test. The addition of Sn not only decreases the particle size of Pt, but also leads to a strong interaction between Pt and SAPO-11. Sn modified Pt/SAPO-11 has much weak Lewis acid sites. Increase of Lewis acid sites and total acid sites enhance isomerization selectivity and deoxygenation rate simultaneously.