A question arises whether the kinetic parameters derived from the Arrhenius equation presented in the literature in fact reflect intrinsic kinetics or are influenced by diffusional effects. It is commonly accepted that diffusion can not only influence (reduce) the reaction rate but also change the observed kinetic constants and reaction order. In this study the limitation of reaction rate (n-hexane catalytic combustion) was observed even at moderate temperatures during experiments performed in a Continuous Stirred Tank Reactor (CSTR), gradientless reactor dedicated to determination of reaction kinetics. In this study a numerical method of the separation of intrinsic kinetics from mass transport effects has been proposed for an experiment executed under significant mass transfer resistance. It was tested using different carrier types (steel sheets and woven wire gauzes) and catalyst formulations for two combustion reactions: of n-hexane and methane. The intrinsic kinetic parameters derived in this way were then used for the numerical simulations of three types of structured reactors filled with: woven and knitted wire gauzes and monolith in terms of the optimization of a reactor length for combustion reactions. The performed simulations showed that the application of woven gauzes as the reactor internals can give rise to substantial decrease of the reactor length even by 10 times for both methane and n-hexane catalytic combustion reactions. (C) 2017 Elsevier Ltd. All rights reserved.