Reducing pollution when burning coal dust in power stations - where dust is briefly gasified and the gas purified before use

摘要

The emission of NOx gases is reduced from a steam generators using dry firing with coal dust by heating the coal dust 800 degrees C. for less than 4 seconds, so that 50-70% of the nitrogen in the dust, and the sulphur, are converted to gas. The coke dust thus obtd. is fed directly, or via a bunker, to the steam generator, whereas the gas is treated to remove noxious substances and possibly reheated; at least part of the gas is then fed to the steam generator.