Roles of bronsted acid sites in composite catalyst for triglyceride cracking

Abstract

The diminishing source of non-renewable energy has spurred the interests of researchers to explore the possibility to use alternative sources. Catalytic cracking of vegetable oil to liquid fuels was studied by a number of individuals and the results were encouraging to continue with this study. Palm oil was chosen because of its abundance in Malaysia. Composite catalyst, Al-MCM-41/ZSM-5 was used to catalytically convert palm oil to gasoline. The effects of temperature, hydrogen addition before (activation) and during (hydrocracking) reaction towards acidity and catalytic cracking were investigated. Catalysts used were characterized using X-ray Diffraction (XRD), Nitrogen Adsorption (NA) and Pyridine Infrared Spectrophotometry (Py-IR) methods. The liquid and gaseous products were analyzed using Gas Chromatography. The results showed that increase in temperature had profound effects towards conversion. The highest Organic Liquid Products (OLP) yield and gasoline selectivity was found at 550°C. Increasing the f low rate of hydrogen activation increased conversion, OLP yield and gasoline selectivity. However, the longer time used for activation had adverse effects on cracking activity. Conversely, increased H2: palm oil molar ratio decreased palm oil conversion and gasoline selectivity.