In process engineering chemical reactions may be classified in gas-phase chemistry, liquid-phase chemistry, and surface chemistry. The latter is essential for the description of heterogeneous catalytic operations. Furthermore, simulations often have to treat reversible reactions and kinetically controlled processes. This paper provides a brief overview of the methodologies, trends, and limits. Three methods are tested for coping with the different challenges of the individual characters of chemical reactions: the CHEMKIN Collection, STAR-CD, and STAR-CD/KINetics (= STAR-CD + CHEMKIN). The results show that the capacity of a tool depends very much on the requirements and specifications of the chemical reactions.