Hydrotreatment of renewable oils using hierarchical mesoporous H-ZSM-5 synthesized from kaolin clay

Abstract

Hierarchical mesoporous ZSM-5 with tailored physicochemical properties was successfully synthesized by using kaolin clay as a cheap alumina source and organosilane as a mesopore directing agent. The synthesized material was used as a support for developing a hydroprocessing catalyst (Ni–Mo). Hydrotreatment of jatropha oil over sulfided Ni–Mo catalyst supported on the developed H-ZSM-5 was carried out. The influence of reaction conditions like temperature, pressure, and LHSV were studied in detail and the results were compared with those obtained for hydrotreatment of jatropha oil using mesoporous ZSM-5 synthesized from conventional precursors. It was observed that the C15–C18 hydrocarbon diesel yield was highest (93%) at a temperature of 375 °C, 50 bar pressure and 1.5 h⁻¹ LHSV, while the C9–C15 hydrocarbon yield (kerosene range) was maximum (37.4%) at a temperature of 425 °C, 80 bar pressure and 0.5 h⁻¹ LHSV. The performance of clay derived catalyst for kerosene production was comparable with that of a conventional catalyst but at higher temperature. But the clay derived catalyst showed higher and more stable activity than the conventional mesoporous zeolite. This may be attributed to milder acidity (due to alumina patches), unlike conventional mesoporous zeolite which has more isolated Al sites and hence a greater number of acid sites.