Reactor system for saturated c3-c6 hydrocarbon dehydrogenation

A method for catalytic dehydrogenation of saturated Cx hydrocarbons comprising:

• feeding saturated Cx hydrocarbons and dehydrogenation catalyst to a reactor within a reactor disengager, where the reactor comprises a reactor zone comprising a lower portion thereof;
• dehydrogenating the saturated Cx hydrocarbons in the presence of the dehydrogenation catalyst to give a reactor effluent feeding through an exit riser to at least one cyclone;
• separating dehydrogenated product from spent catalyst in the at least one cyclone;
• flowing the spent catalyst down an annular space between the disengager and the reactor to a spent catalyst stripper and a catalyst regenerator;
• where the lower portion of the reactor is open to the disengager and in fluid communication with the annular space, and the method further comprises controlling the amount of catalyst within the reactor by varying the level of catalyst in the annular space.