The methanol-to-olefins (MTO) and methanol-to-propylene (MTP) processes are important ways to convert coal to chemicals. Successfully commercialized processes in recent years include the DMTO

s-MTO

MTO+OCP and MTP technologies developed respectively by Dalian Institute of Chemical Physics

SINOPEC

UOP and Lurgi. This paper analyzes the characteristics of the heterogeneous catalytic reactions in the MTO process

and on this basis discusses various multiphase catalytic reactors used for converting methanol to olefins. Key features and specifications of different technologies

and the similarity and difference between the MTO and fluidized catalytic cracking processes are compared. The MTO reactions occur by hydrocarbon pool reaction mechanism

which has autocatalytic and coking deactivation behavior that makes it important to control the working state of the catalyst and limit back-mixing in the reactor to achieve good activity and olefin selectivity. The use of a hierarchical zeolite catalyst and a fluidized bed reactor with little back-mixing or a reactors-in-series assembly is suggested as potential improvement for the process.