2019 Volume 61 Issue 198 Pages 304-308
This paper informs the achievements of the research activity related to the direct combustion of ammonia for the coal fired power plant. There are some technical issues expected in the ammonia utilization for the coal fired power plant. One is the increase of the NO concentration in the exhaust gas. Another is the inflection of the local heat flux on the boiler wall. The first issue related to the NO concentration was solved by the experimental approach with the 10 MW thermal input test facility. NO generation was under controlled by injecting the ammonia into the strong reduction zone, that is created by the coal combustion. Ammonia was well decomposed into the nitrogen and hydrogen in such a strong reduction zone. By this experiment, it was proved that the ammonia can be safely co-fired with coal by 20% in the calorific base. The second issue related to the heat flux on the boiler wall was discussed by the numerical analysis. The size of the boiler in this discussion was 1000 MW which is the biggest size in the present market. Although the gas temperature in the ammonia co-firing is a slightly lower than that in the coal firing, there is not largely different in the local heat flux nor total heat flux between coal firing and ammonia co-firing conditions. For the next step to penetrate this technology into the society, the demonstration in the commercial scale boiler is demanded.