抄録
In order to improve the thermal efficiency of the oxygen-blown IGCC (Integrated Gasification Combined Cycle) to meet stricter environmental standards and as a cost-effective option, it is necessary to adopt the hot/dry gas cleaning system. In this system, the flame temperature of medium-Btu gasified fuel is higher and so NOx production from nitrogen fixation is expected to increase significantly. Moreover, the gasified fuel contains fuel nitrogen, such as ammonia, which produce the fuel NOx emissions in the case of employing the hot/dry gas cleaning system. Low NOx combustion technology to reduce both fuel-NOx and thermal-NOx emissions has to be developed in order to contribute to the protection of the environment and ensure low cost operations of all kinds of oxygen-blown IGCC. In this paper, we have clarified the effectiveness of applying both two-stage combustion and nitrogen injection, as well as indicating useful engineering guidelines for the low-NOx combustor design of oxygen-blown gasified, medium-Btu fuels.
