Production of Normal Paraffins with an Even Carbon Number via Selective Hydrodeoxygenation of Palm Fatty Acid Distillate over Pt–Sn Catalysts
Kihoon Kim, Daisuke Higai, Xiaofan Hou, Mingming Peng, Eika W. Qian
Abstract
Two series of supports, SAPO-11 (Si/Al: 0–0.4) and alumina-coated SBA-15 (Al2O3: 0–20 wt %), with different pore structures were synthesized. Subsequently, the PtSn bimetallic catalysts supported on these supports were prepared using a co-impregnation method and were characterized by N2 adsorption measurement, pyridine-adsorbed Fourier transform infrared, CO chemisorption, and H2-TPR. The catalytic performances of the catalysts in the hydrotreatment of palm fatty acid distillate (PFAD) were tested using a fixed-bed flow reactor system. PtSn/ALPO-11 (Si/Al: 0) showed the highest n-C16,18 selectivity (66.4%) among the SAPO-11-based catalysts, and PtSn/20Al/SBA-15 (20% Al2O3) showed the highest n-C16, n-C18 selectivity (61.5%) among the SBA-15-based catalysts. It was found that higher Brønsted acid content on the catalyst showed higher isomerization selectivity. Based on the comparison of PtSn/SAPO-11 (0.1) and PtSn/10Al/SBA-15, the mesoporous structure favored hydrodeoxygenation activity. Also, it was suggested that Brønsted acid affected the structure of active sites and highly dispersed Pt favored formation of n-hexadecane and n-octadecane.