(351c) Microwave-Assisted Dehydrogenation of Ethane over Stable Csru/CeO2 Catalyst for Production of Light Olefins

Light olefins such as ethylene, propylene, and butenes which are well known as raw chemicals of the chemical industry, have been widely used to produce fibers, plastics, synthetic rubber, etc. Currently, C₂ and C₃ olefins are mainly made from natural gas via multi-step processes, syngas formation, methanol synthesis and MTO. Moreover, there is no commercial C₄ olefins production process using natural gas as feedstock. Direct nonoxidative dehydrogenation is promising for production of light olefins from natural gas. However, the nonoxidative dehydrogenation suffers from rapid catalyst deactivation resulting from coke formation.

In this study, a novel catalytic process for direct conversion of natural gas to light olefins was developed. Under microwave irradiation, the light olefins were efficiently produced over CsRu/CeO₂ catalyst using ethane as feedstock. The CsRu/CeO₂ catalyst demonstrates extremely high activity and selectivity towards light olefins. For example, at 600 °C and atmosphere pressure, ethane conversion reached to 74%, with 76% light olefins selectivity. Beside C₂ and C₃ olefins, C₄ olefins are also formed. Specially, C₄ olefins consisted of mainly 1,3-butadien which is the raw material for producing synthetic rubber, such as styrene-butadiene rubber, polybutadiene rubber, acrylonitrile–butadiene–styrene, nitrile rubbers, and chloroprene rubber, etc. Moreover, the CsRu/CeO₂ catalyst demonstrates superior stability during the catalytic process. After total 72 hours’ time-on-stream test, the CsRu/CeO₂ catalyst still maintained high activity without any sign of deactivation, even with the variation of reaction conditions (temperature and feeding) and several on-purpose shut-down and start-up. This work demonstrates that there is significant potential for cost effective conversion of natural gas to light olefins by microwave catalytic technology.