Effect of ammonia on the characteristics of coal combustion

Abstract

Ammonia is a kind of zero-carbon fuel with mature technology and low storage and transportation cost. Partial replacement of coal with ammonia can become an effective way to reduce carbon at the front end of coal-fired units under the dual carbon target. In this paper, zero-carbon ammonia fuel is studied as an alternative fuel. The fuel characteristics of ammonia and its mixed fuel with typical bituminous coal are studied by using one-dimensional flame furnace and ignition furnace. The ignition performance changes of ammonia/coal mixed fuel, the enhanced combustion and pollutant control technology of different proportions of ammonia/coal mixed fuel are studied and analyzed in detail. It is found that the pre-mixed combustion of ammonia/coal is not conducive to NOx control. Through the classification of ammonia/coal fuel, the control of excess air coefficient or oxygen content, supplemented by air-staged combustion, 25% or even higher proportion of ammonia blending can achieve lower NOx concentration and better combustion effect than raw coal. Partial replacement of coal with ammonia can reduce slagging and improve the safety of actual combustion process.