Abstract: The NOx emission control and system efficiency increasing of IGCC power plant were analyzed and calculated theoretically. The nitrogen dilution process and W+SCR process were compared in different aspects including thermal efficiency, technical risk and economical efficiency. The conclusion shows W+SCR is the most economical and reliable method at the present time for reducing NOx emission, in addition to this, the system efficiency can also be raised by using W+SCR method.

Key words: integrated gasification combined cycles (IGCC) power generating, nitrogen dilution method, W+SCR method, NOx emission control, system efficiency optimization