A new environmentally sound and economically effective process of propylene production by propane dehydrogenation in a fluidized catalyst bed was worked out and tested in a pilot unit. Mathematical models that allow the design of reactors with optimal parameters and a large unit capacity for the production of propylene, as well as isobutylene and isoamylenes, were generated. The adequacy of the models was fully confirmed by examining the operation of large commercial olefin, production units. The models may also be applied to both diagnostics of possible operation failures of reactors and optimization of their operation.