Selective Production of Light Olefins over MSE-type Zeolite Catalyst

Abstract

Selective production of propylene was investigated with preparation routes to MSE-type zeolite catalysts, microporous aluminosilicates with a 12-10-10-ring micropore system. Some examples of catalytic application including the conversions of petroleum and non-petroleum resources are reviewed. Variation of the synthetic route provided characteristic aluminosilicate MSE-type materials that exhibited improved catalytic performances for hexane cracking. La-modification is effective for enhancing the catalytic performance in hexane cracking. To control the acid sites distribution in MCM-68 zeolite catalyst, phosphate-loaded MCM-68 catalyst was prepared by impregnation and subsequent calcination. Phosphate impregnation increased the selectivity to propylene and butenes in the dimethyl ether-to-olefin (DTO) reaction. The propylene/ethylene ratio in the products was significantly increased by phosphate modification. Phosphate-modified MCM-68 showed high resistance to coke formation, indicating that this modification technique is useful to obtain long-lived catalysts in the DTO reaction. Ce-modification of dealuminated MCM-68 enhanced the stability. Successive calcination at 800 °C generated selective and long-lived catalyst for dimethyl ether-to-olefin reaction, resulting in high propylene yield.