(304f) Kinetic Modeling of Methanol to Olefins (MTO) On SAPO-34 Catalyst

Methanol to olefins (MTO) coupled with transformation of coal or natural gas to methanol gives an interesting and promising way to produce ethylene and propylene. The kinetics of methanol conversion to olefins on SAPO-34 catalyst was studied in an isothermal multiple fixed bed reactors in parallel. A reaction kinetic model including five lumps was proposed on the basis of Hydrocarbon Pool parallel reaction and parallel deactivation of catalyst. The influence of water and coke deposition was considered in the model. The simulation in fixed bed reactor using the obtained general kinetic equations was performed and also compared with the experimental value. The result showed a good match between the estimated and experimental values. The average activity of catalyst showed a corresponding evolution with the increasing coke formation. Some water could be effective to reduce the deactivation of catalyst and methanol conversion did not drop instantaneously but instead it remained constant for some time before deactivation breakthrough. An empirical model for the coke formation was obtained and made the coke content as a function of time on stream, temperature, WHSV, water/methanol in feed. The obtained model showed a very good linearity correlation.

A simulation using the bubble fluidized bed reactor model coupled with the obtained kinetic model to predict the performance of MTO was performed. The values calculated by the model were identical to the experimental ones. Besides, the probability application of riser reactor in MTO process was also investigated.