Chemical reactors are a central component of industrial processes for the production of chemical products. Since, in addition to the reactors, other systems for substance separation, as well as for substance and energy integration within the overall process along the process chain, are necessary, there are strong dependencies between the various subsystems. The design of the reaction system has great significance and influence on the thermodynamic, economic and ecological efficiency of the overall process. To find optimal solutions in the interplay among these criteria, various approaches for synthesis, analysis, evaluation and optimization of the process design are available. Knowledge-based approaches, thermodynamic methods and mathematical optimization algorithms can be applied. Against this background, exergy analysis offers as the only method the possibility to consider the process taking into account the unity of substance and energy transformation along the entire life cycle and to integrate economic and ecological considerations.