Integrated Study On Denitraton Methods Of IGCC Plant

Took IGCC plant with9F type gas turbine as research object. Techno-economicsanalysis of Nitrogen injection、Steam injection、SCR and the combination of denitrationwas undertook. We got the reasonable boundary conditions of various measures tocontrol NOxemissions and the optimal denitration way under given boundary condition.The specific was as follows:(1) Mechanism of NOxformation was discussed and the ways to control NOxemissions of low calorific value gas turbine at home and abroad were tracked. Finally weobtained several key denitration methods.(2) Took power island of IGCC plant as the research object, selected GE9351FAtype gas turbine and its boundary conditions. The structure and steam parameters ofHRSG and steam turbine were attained according to the principle of IGCC systemmodule selection. The process simulation software Thermoflex was selected to buildIGCC system model.(3) Research results on optimal Xasof the IGCC system with nitrogen injection showthat the corresponding Xasreduces while the Xgndecreases. IGCC system is suitable forthe independent low pressure air separation system when the Xgnis less than40%.(4) Comparative study of different denitration method indicates that SCR got bettertechno-economic indexes, and the properties improved with the integrated designbetween diluent injection and SCR and integrated optimization of nitrogen injection. Thesensitive analysis results show that the electricity and fuel prices are more sensitive.From the point of techno-economic index, performance of SCR is superior tonitrogen injection. However, SCR faces the safety problems such as catalyst deactivationand ammonia leakage, and the current SCR efficiency is hard to reach94%. Moreover,the waste catalyst also can causes secondary pollution to the environment.Techno-economic properties of nitrogen injection will be further improved and have anadvantage in energy conservation and environmental protection as the key equipment andIGCC system integration level promote. Nitrogen injection has more developmentpotential based on the national conditions which need to develop energy-saving andenvironment protection power generation technology.