Methanol to Propylene Process in a Moving Bed Reactor with Byproducts Recycling: Kinetic Study and Reactor Simulation

A moving bed reactor concept was introduced to the methanol to propylene process. To implement this concept, a modified kinetic model of MTP reaction on a special HZSM-5 pellet catalyst was developed; a moving bed reactor model in propylene yield platform period was proposed. Applying these two models, a two-stage moving bed in series with methanol quenched between stages was investigated. Water and part of the byproducts were recycled to the first moving bed reactor. Simulation results showed that the recycle of byproducts could increase the yield of propylene to 70%. The roles of higher hydrocarbons in the two reactors were different since they acted as reactants in the first moving bed while as products in the second one.