Optimization of the Decoking Procedure of an Ethane Cracker with a Steam/Air Mixture

Using a heterogeneous plug flow model for the reactor tubes and a general gas-solid reaction/diffusion model with intrinsic reaction kinetics for coke combustion and coke gasification, an in-depth study on the influence of seven operating parameters of the decoking procedure of an ethane cracking furnace is performed. On the basis of the results of this study, the air and steam flow to the reactor tubes during the decoking procedure are adapted to propose an optimized decoking procedure that allows reducing the required decoking time of an industrial ethane cracking furnace by a factor of 3. In the new decoking conditions for the ethane cracker, the air flow rate is raised by a factor of 3, while the steam dilution is lowered by a factor of 4.5.