Production of Normal Paraffins with an Even Carbon Number via Selective Hydrodeoxygenation of Palm Fatty Acid Distillate over Pt- Sn Catalysts

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 N-2 adsorption measurement, pyridine-adsorbed Fourier transform infrared, CO chemisorption, and H-2-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-C-16,C-18 selectivity (66.4%) among the SAPO-11-based catalysts, and PtSn/20A1/SBA-1S (20% Al2O3) showed the highest n-C-16, n-C-18 selectivity (61.5%) among the SBA-15-based catalysts. It was found that higher Bronsted 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 Bronsted acid affected the structure of active sites and highly dispersed Pt favored formation of n-hexadecane and n-octadecane.

Automated summary

The study found that the Bronsted acid content on the catalyst and the mesoporous structure play a crucial role in the hydrotreatment of palm fatty acid distillate, affecting the structure of active sites and the formation of products.