Economic and environmental analysis of IGCC power generation with SCR technology for further NO{sub}x reduction

摘要

Integrated coal gasification combined cycle (IGCC) power generation technologies are being developed to significantly increase the efficiency of coal-fired power generation and to drastically reduce emissions of pollutants. Coal-based IGCC plants have proven to be capable of exceeding the most stringent emissions regulations currently applicable to coal-fired power plants. Specifically, IGCC plants achieve the lowest levels of NO{sub}x emissions of any coal-fired power plants in the world. IGCC technologies incorporating low NO{sub}x burners in their combustion turbines are capable of achieving unprecedented NO{sub}x emission levels for coal-fired plants [less than 0.5 lb NOx/MWh. This can be compared to the Federal new source performance standards (NSPS) for new plants burning any type of fuel of 1.6 lb/MWh]. However, there are indications that coal-based IGCC plants may be regulated as natural gas fired plants because they utilize gas turbines. If this turns out to be the case, further reduction in NO{sub}x emissions from IGCC may be required to levels of about 0.1 lb/MWh. This is equivalent to about 3 ppmv on a 15 percent excess oxygen basis. In order to achieve these low NO{sub}x levels the addition of selective catalytic reduction (SCR) technology will be necessary in addition to the low NO{sub}x burner gas turbine combustor design. This paper investigates the environmental and economic impact of applying SCR to a typical coal-based IGCC plant. The configurational changes needed to incorporate SCR are analyzed and the resulting impact on the cost of electricity and the cost of NO{sub}x removed are calculated.