Investigation of coke deposition during catalytic cracking of different biomass model tar: Effect of microwave

Tar is one of the biggest obstacles for commercial application of biomass gasification. Microwave catalytic cracking shows potential for not only removal but also conversion of tar. However, the coke formation under microwave has not been investigated. In the present work, a microwave applicable catalyst, Ni-Ce@SiC, was prepared. The effects of temperature and inlet tar concentration on toluene and phenol conversions were investigated under both microwave and conventional heating conditions, and the influences on coking rate were also focused. Results showed that increasing temperature and reducing inlet tar concentration improved tar conversion. Inlet tar concentration and cracking of phenol typically caused more coke deposition. Based on the characterizations of the spent catalysts, the microwave could eliminate the coke deposition and alter the coke types. The mechanism of microwave on the coke suppression was revealed. This study provids an in-depth understanding of the coke formation during the microwave process, and also builds foundation for the design and operation of catalytic process.