Based on the simulated trajectories of particles, residence times in each pore and porous material can be determined in the AddiDict post-processing. From these residence times, chemical reactions of first order can be computed as a next step.

First order chemical reactions are simple chemical reactions that describe a reduction of a reactant A (here a kind of molecule), while the catalyst is not consumed. The change in amount of [A] is determined by the rate constant k:

i.e., the amount of [A] is reduced exponentially, with a half-life time of:

The remaining amount of [A] can therefore simply be computed from the residence times and the rate constant k: