Ernst-Ulrich Hartge

This review of industrial applications of fluidized‐bed reactors is focused on the fluid catalytic cracking (FCC) process and the fluidized‐bed combustion. Both processes have a tremendous economic importance. In the FCC process, the main challenges are the increase of runtime, the adaption of the product spectrum to regional requirements of the market, and the adaption to heavier feedstocks. In fluidized‐bed combustion the main trends are towards larger units sizes, higher efficiency, and further reduced emissions while keeping the boiler as flexible as possible with regard to the mixture of fuels.

Flowsheet modeling of processes with liquid, vapor, and solid phases is a very challenging task, since the description of granular materials is complicated by their disparity. On the other hand, the functional models of different apparatuses often contain a large set of empirical parameters which strongly depend on material properties and apparatus geometry. In this contribution the main problems related to the flowsheet simulation of solids processes are discussed and the usage of additional scales in the process description is proposed to estimate model parameters.