Process of converting methanol to olefins

A process of converting methanol to olefins, comprising:

• feeding a feedstock comprising methanol to a fluidized bed reactor to contact with catalysts to produce an olefin product, wherein the process at least partially deactivates the catalysts to form at least partially deactivated catalysts;
• feeding spent catalysts from the at least partially deactivated catalysts to a regenerator for regeneration, thereby forming regenerated catalysts, and returning activated catalysts from the regenerated catalysts to the reactor via a regenerated catalyst line;
• wherein
• on the regenerated catalyst line, an oxygen content by volume in a gas phase component at an outlet of the regenerated catalyst line is controlled to be 0.01% or less than 0.01%, and
• the spent catalysts are regenerated by feeding the spent catalysts through a spent catalyst line to a regenerator, wherein on the spent catalyst line, a steam content by volume in the gas phase component at an outlet of the spent catalyst line is controlled to be 0.05% or less than 0.05%.