The course of the error is shown in Figure A.1 in the appendix for the binary friction model and exhibits minimal values in the range of 6 ≤ 𝜏 ≤ 7 (minimum at 6.7). A comparison with the Wilke-Bosanquet model shows negligible differences in the error, which confirms the applicability of the chosen diffusion model based on a more extensive comparison done in our previous work . It has to be mentioned that this range somewhat exceeds the expected value of ca. 3 , but is still reasonable, since it may reach rather high values as well . Importantly, the tortuosity is the only model parameter used and thus, all simplifications of the experiment are lumped into this parameter. For instance, the assumptions regarding the pore structure (e.g., monomodal pore size distribution and irrelevant pore geometry) induce certain deviations between simulation and experiment, which affect the model parameter.