Evolution patterns and family relations in G-S reactors

Reactor selection strategies for gas–solid (G–S) heterogeneously catalysed processes can be based on the requirements of the desired process and the properties of the reactions and catalysts involved. Ultimately a reactor selection will nearly always be grounded on existing or emerging reactor types slightly modified for adaptation to the specific chemical process. This procedure results in radiation of different reactor modifications from the archetypes towards niche applications. It is shown that this process has a lot of resemblance with the evolution process of animal species. The G–S heterogeneous catalytic reactors can be classified into three or four families. They are presented as adaptations from only three archetypes: packed bed, fluid bed and barrier wall. The properties of these reactors and their family members are discussed. Examples are given of a few relatively new variants and of competition of very different reactors for the same application niche. The classification system can be used as a means for the creation of new reactors and if extended with a database or knowledge system it can facilitate reactor selection. Similar classifications can be set-up for other types of chemical reactors like G–L and G–L–S reactors.