1. Classification of chemical reactions and reactors

Table 1 summarizes the main criteria for classifying chemical transformations.

Of the criteria listed, the one that dominates most often leaves its mark on reactor design and operation: in a gas/solid reaction, material and heat transfer between phases are decisive factors; in a reaction with a single stoichiometry, the aim is generally to obtain the maximum conversion rate at the lowest cost in the smallest possible reactor, or in the shortest possible time, whereas in a reaction with multiple stoichiometries, achieving high selectivity takes precedence over the conversion rate if recycling unconverted substances is not too costly ; in a balanced exothermic reaction, temperature control is crucial; finally, when the efficiency of the transformation depends entirely on the choice of a good catalyst, chemical...