Seung Kyo Oh  Euna Jung  Jungyeop Lee  Jong-Ki Jeon

Vol. 31,  No. 1, pp. 24-32, Mar.  2025
10.7464/ksct.2025.31.1.24

Bio oil Bio jet-fuel n-octadecane Hydroupgrading Pt/HY

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The objective of this study is to investigate the characteristics and reaction properties of Pt/HY catalysts for hydro-upgrading reaction to produce bio-jet fuel from bio-oil. Pt catalysts supported on HY zeolite were synthesized, and their Si/Al₂ ratio was varied to evaluate catalyst properties and reactivity. BET, NH₃-TPD, and pyridine FT-IR analyses were conducted to characterize the catalysts. The hydro-upgrading reaction, which involves simultaneous hydrocracking and isomerization, was studied using n-octadecane as a model compound. This study aims to elucidate the influence of the structure and acid sites of Pt/HY catalysts on the hydro-upgrading performance of n-octadecane and to propose optimal catalyst conditions. It was observed that as the Si/Al₂ molar ratio of the synthesized Pt/HY catalysts increased from 5.2 to 60, the development of mesopores became more pronounced. NH₃-TPD analysis revealed that as the Si/Al₂ ratio increased, both the number and strength of acid sites decreased, and the ratio of weak to strong acid sites gradually declined. Furthermore, an increase in the Si/Al₂ ratio led to a reduction in Brønsted acid sites. The hydro-upgrading reaction of n-octadecane using Pt/HY catalysts was conducted in a continuous fixed-bed reactor. Pt/HY(60) exhibited the highest conversion, while a decreasing Si/Al₂ molar ratio resulted in lower conversion. The Pt/HY(60) catalyst also showed the highest selectivity and yield for jet fuel-range hydrocarbons (C8~C17), as well as excellent isomer selectivity. These results suggest that in the hydro-upgrading reaction of n-octadecane, the acid site density and strength of the Pt/HY(60) catalyst are optimal for achieving a suitable balance between cracking and isomerization to produce jet fuel fractions. Additionally, when evaluating the effect of reaction pressure on the hydro-upgrading of n-octadecane using Pt/HY(60), the highest jet fuel yield was obtained at 10 bar, while isomer selectivity was not significantly affected by pressure.