ABSTRACT
Chemical reactions between a granular solid and a fluid are complicated by the difficulties of solids handling. In a fluidised bed the granular material is subjected to an upflow of fluid sufficient to support its weight. The solid then behaves as a fluid and can readily be transferred to and from the reactor. Fluidised beds are advantageous for exothermic reactions since the efficient mixing within the bed not only helps to eliminate the formation of hot-spots typical of such reactions in fixed beds but also facilitates heat transfer to the walls of the bed. In a fluidised bed of non-porous particles, the reaction takes place on the particle surface, whether the particle is behaving as a catalyst or reacting itself. The simplest case of a fluidised bed reactor is when the apparent reaction within the particulate phase is first order and when the particulate phase is well mixed.
