Liquid hydrocarbon fuels from palm oil by catalytic cracking over aluminosilicate mesoporous catalysts with various Si/Al ratios

Abstract

The production of liquid fuels from palm oil was studied at atmospheric pressure, reaction temperature of 723 K and weight hourly space velocity of 2.5 h −1 in a fixed bed micro-reactor containing aluminosilicate mesoporous material as cracking catalysts. The aluminosilicate materials with different Si/Al ratios were synthesized by direct (sol–gel and hydrothermal) and post-synthesis (ion-exchange and grafting) methods. The synthesized materials were characterized for their crystallinity, surface area, average pore size, elemental composition and acidity. The role of aluminum present in the mesoporous catalyst was studied in terms of its cracking activity. Palm oil conversions of 80–90 wt% with high selectivity to liquid hydrocarbon products were obtained. The catalysts prepared by sol–gel and grafting methods showed lower activity due to the presence of octahedrally coordinated Al in the framework. The activity of the catalyst increased with the aluminum content up to an optimum level. The higher Al content decreased the crystallinity and therefore catalytic activity for the cracking of palm oil.