Fluidized-Bed Combustion Technology—A Review

Abstract

Fluidized-bed combustion of coal is now recognized as an economically viable process with a great potential to enhance coal utilization and thereby lessen the ever increasing burden on the scarce petroleum derived fuels. Significant efforts are now underway, in the U.S. and abroad, to rapidly develop the fluidized-bed combustion technology. Thus far, experimental studies with laboratory- and bench-scale units and with process demonstration units have adequately established the technical feasibility of the fluidized-bed combustion process technology. These studies have identified and attempted characterization of the overall processes but much is yet to be learned. The fluidized-bed combustion process involves complex interactions between several physical and chemical processes encompassing the disciplines of fluid/solid (particle) mechanics, combustion/chemical kinetics and heat transfer. The current state of fluidized-bed combustion technology could greatly benefit from a further research and development effort essentially aimed at the characterization of the governing mechanisms for coal combustion in steady and transient operations. This paper briefly examines the combustion related aspects of fluidized-bed combustion systems in normal (steady state) mode of operation while introducing the concept of fluidized beds to combustion scientists