The macroscopic behavior of a chemical process is essentially driven by kinetic phenomena. For
most chemical processes one has to deal with more or less complex flows which define the mixing
quality and/or mass transfer. Chemical reactions in these types of systems to a large extent depend
on the underlying flow patterns. In this paper we present a short review on mathematical modeling
and numerical simulations of different types of chemical processes. The appropriate mathematical
description of the flow and the correct implementation of reactions for three different cases of gassolid,
single-phase liquid, and liquid-liquid flow in a channel are presented. Finally the obtained
results are compared with experimental data.