Introduction

The analysis and design of multiphase reactors is one of the most intensely studied areas of chemical reaction engineering. The types of industrial fluid/solid reactors can be largely divided into two categories: one where solids are fixed and the other where solids are in a suspended state. Solids suspension may be achieved by stirring (stirred slurry reactor), by gas-induced liquid motion (slurry bubble column or airlift) or by forced liquid flow (three-phase fluidized bed). The reactors are sketched in Figure I.1 . For a particular reaction, it may not always be clear which reactor type is most advantageous. Different types have to be considered or are actually used for the same conversion (e.g. Fischer-Tropsch synthesis). However, it may be beyond the scope of any single book to cover all types of multiphase reactors in detail.