Gas cleaning at high temperatures and high pressures: A review

This is a review of gas cleaning methods to be used for particulate removal from the gases emerging from pressurized coal gasifiers or fluid bed combustors at high temperature and high pressure. References are given (collected in tables) for the emissions of these processes, the inlet requirements if the hot gas is to pass a turbine and all cleaning methods that have been proposed in this context, including the removal of gaseous alkalis.

The design feasibility and available performance data for high temperature, high pressure applications of cyclones, electrostatic precipitators, barrier filters (using fibre, felt and sintered filter elements) and various types of granular bed filters, are discussed in some detail and suggestions are made for the further research and development. The theory of capture mechanisms is reviewed in so far as relevant in the present context. Turbulent flow, electrostatic forces, and re-entrainment are the phenomena that require special attention in almost all applications.