Patent ID: 7273960

Claim:
A process for controlling a circulating fluid bed oxygenates to olefins reactor which comprises: contacting an oxygenate-containing feedstock in a circulating fluid bed reaction zone in the presence of a molecular sieve oxygenates to olefins conversion catalyst under oxygenate conversion conditions, wherein the catalyst circulates between a reactor and a regenerator; measuring reactant feed rate, as a variable functionally corresponding to space velocity, defined as: Mass flow rate of reactant feed per hour/Mass of active catalyst ingredient in the reactor wherein the mass flow rate of reactant feed is controlled by at least one feed flow control valve and the mass of active catalyst ingredient is regulated by at least one valve means for controlling catalyst circulation; comparing said measured reactant feed rate with an optimal reactant feed rate to provide a signal which is a function of the difference between said measured and said optimal reactant feed rate; and adjusting as a function of said signal the at least one feed flow control valve and the amount of active catalyst in the reaction zone at least one valve means to improve at least one of light olefin production rate and light olefin selectivity.