Abstract
The major cause of deactivation in the MTO reaction over SAPO-34 is coke deposition that influences both activity and selectivity. This review describes different kinetic modeling of deactivation of SAPO-34 during MTO process. It also presents different deactivation functions for the methanol conversion and the yields of olefins, which are hyperbolic and exponential respectively. A modified Voorhies model that estimates the average coke selectivity and catalyst capacity for olefin formation describes a good relation between coke deposition and the amount of hydrocarbons formed per gram of catalyst. Relation between the coke content over SAPO-34 and cumulative amount of methanol fed to the catalysts is presented to estimate the coke content on SAPO-34 at different reaction conditions. In addition, the changes in activity and selectivity with the coke content are simulated by a kinetic model, which includes the deactivation effect.
