Secondary cracking suppression through Pt/H-BEA: n-Hexadecane hydrocracking

Abstract

This paper reports secondary cracking suppression through Pt/H-BEA in n-C16 hydrocracking. H-BEA (C) and H-BEA (H) of SiO2/Al2O3 ratios: 17, 23, and 25 were prepared by hydrothermal method and steam-assisted conversion method, respectively, and platinum loading was performed using incipient wetness impregnation. Pt/H-BEA (H) catalysts exhibited predominantly mesoporous structure by nitrogen physisorption and lower acid site density by NH3-TPD and Pt/H-BEA (C) exhibited unusually high mesoporosity based on our synthesis gel chemistry. Both catalysts had high secondary cracking reactions suppression but Pt/H-BEA23 (H) exhibited superior and perfect suppression with C6/C10 ∼ 1 and symmetrical cracking products carbon number molar distribution at several n-C16 conversions. Pt/H-BEA (H), consequently, had highest jet fuel hydrocarbons (C9+) selectivity with 81% achieved by Pt/H-BEA23 (H) at 50% conversion. It, additionally, had lower coke deposition which decreased with increased SiO2/Al2O3 ratio as a result of lower diffusion limitations and secondary cracking reactions. Pt/H-BEA, in conclusion, exhibits excellent ability to suppress secondary cracking reactions for high jet fuels hydrocarbons selectivity and diesel selectivity in Fischer-Tropsch wax hydrocracking considering n-C16 as a feed model and H-BEA (H) greatly improves the performances.