Recommendations for mode of operation and critical dimensions regarding inner mass transfer limitation were deduced for the technical extraction of silicon from silicon carbide to produce nanoporous carbon (carbide-derived carbon, CDC). The recommendations are based on intrinsic kinetics derived from experimental data and reaction engineering simulation of the transient process (shrinking-core like mechanism). As the reaction takes place at 1000 degrees C under chlorine atmosphere, kinetic data as well as diffusion coefficients are extracted from integral conversion data in a lab scale reactor. The reaction rate dependency for varying chlorine concentrations is represented best by a Hougen-Watson type rate approach with dissociative adsorption of a reactant. From the experimental data the effective diffusion coefficient of chlorine in the resulting nanoporous carbon could also be derived to 4 center dot 108?m2s1 at 1000 degrees C.