Catalytic cracking of soybean oil by ZSM-5 zeolite-containing silica-aluminas with three layered micro-meso-meso-structure

Abstract

In order to convert a large molecule of soybean oil, ZSM-5 zeolite-containing silica-aluminas with three layered micro-meso-meso-structure were developed. In this method, zeolite-containing two layered silica-aluminas initially prepared were combined with silicas having very large mesopores prepared by the gel skeletal reinforcement. The three-layered structure was confirmed by pore size distribution derived from N2 adsorption and desorption measurements. The catalytic cracking of soybean oil using the three-layered catalysts was evaluated by the Curie point pyrolyzer method. When the reaction was performed at 500°C, activities of catalysts having hierarchical structures were improved. It is thought that the diffusion of soybean oil molecule was promoted in the presence of large mesopores of the catalysts having hierarchical structure. ZSM-5 zeolite-containing catalysts showed very high research octane number (RON), compared with β zeolite and Y zeolite containing catalysts, indicating that ZSM zeolite-containing catalysts provided gasoline fractions of good quality. Gasoline yields increased with increasing conversion and was plotted on the same straight line when the same type of zeolite was used, indicating that the product selectivity would depend on the type of zeolite and that the activity would strongly depend on the existence of the matrix.