N2O EMISSION CONTROL IN COAL COMBUSTION

Interactions among SO(x), NO(x) and N2O, as well as among methods for their abatement, are discussed and guidelines for the development of N2O control in fluidized-bed combustion (FBC) are proposed. An integrated approach to pollution control is advocated rather than treatment of each pollutant separately. Improvements in operating conditions, start-up procedures and process control are examples of low-cost measures. However, innovative combustor design is required to produce low-emission systems that would meet increasingly stringent standards. Temperature optimization itself is insufficient; gas afterburning and solid-catalysed N2O decomposition are identified as the most promising measures. FBC flue-gas treatment is deemed unattractive, unless it can be made inexpensive and easy to install or retrofit.