Based on the fundamentals of stoichiometry, thermodynamics, reaction kinetics, and the laws of mass and heat transfer, chemical reaction engineering provides the experimental and theoretical data as well as the mathematical tools for the design of chemical reactors. The starting point of any reactor design is the material and heat balances in the given balance space. The reactor calculation is based on differential equations that are based on conservation laws for mass, energy, and momentum. From this, design equations for ideal or real reactors can be derived.