Industrial & Engineering Chemistry Research, Vol.58, No.1, 27-33, 2019
Methanol to Propylene over Foam SiC-Supported ZSM-5 Catalyst: Performance of Multiple Reaction-Regeneration Cycles
Due to the superior performance in thermal conductivity and mechanical strength, the foam SiC-supported ZSM-S catalyst is favorable in fixed bed methanol-to-propylene (MTP) reactions, where the temperature distribution and pressure drop are strictly controlled. However, its performance and service life in multiple reaction-regeneration cycles has not been proved yet. Both the activity and selectivity of the catalyst will be tested in six reaction-regeneration cycles in a fixed bed reactor. In addition, the properties of the catalyst during the fourth cycle were characterized by various techniques (scanning electron microscopy, Brunauer-Emmett-Teller, Al-27 nuclear magnetic resonance). The results show that, as the reaction progresses, the catalyst continuously deposits carbon, and the local high temperature of carbon burning during regeneration leads to the removal of aluminum from the zeolite framework. Therefore, the catalyst life in one single process increases first and then decreases. At the same time, the propylene selectivity also experiences rapid rising, steady rising, and rapid descent periods; the steady rising period is the best MTP reaction period of operation.