Simulation of the decoking of an ethane cracker with a steam/air mixture

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

“…A complete overview of the process gas model equations and the correlations used for the calculations of the heat and mass transfer coefficients and of the physical properties of the gases is found in the work of Heynderickx et al 17 2.2.3. Coke Layer Model Equations.…”

“…A complete overview of the coke layer model equations is given by Heynderickx et al 17 It must be remarked that the coke layer is considered to have a uniform structure over the entire reactor length. Heterogeneities, e.g., cracked coke due to the difference in the thermal expansion coefficient of the coke and reactor tube material, and their influence on the decoking kinetics, e.g., fast ignition resulting in local hot spots, are not taken into account in the simulations.…”

“…Conditions. The model is completed with an extensive set of initial and boundary conditions, an overview of which is given by Heynderickx et al 17 2.2.5. Fragmentation of the Coke Layer.…”

“…The combustion of coke to carbon oxide does not have to be considered as discussed by Heynderickx et al 16,17 An adequate gas-solid reaction/diffusion model and an adequate coke texture model, part of a complete reactor model, were recently developed and validated by Heynderickx et al 16,17 for an industrial ethane cracker.…”

“…Performing a coupled simulation of furnace and reactor coils allows an accurate calculation of the run length of the decoking procedure of an industrial cracker unit. 17 In this paper, the above-mentioned validated models are used to study the influence of various operating conditions during an ethane steam cracking furnace decoking procedure, resulting in the proposal of an optimized decoking procedure for an industrial ethane steam cracker, which allows reducing the required decoking time by a factor of 3.…”