CO{sub 2} capture for PC boilers using flue-gas recirculation : evaluation of CO{sub 2} recovery, transport, and utilization.

The U.S. Department of Energy (DOE) is investigating retrofitting boilers with flue gas recirculation as a strategy for CO{sub 2} recovery from conventional pulverized coal (PC) plants because of the current motivation to reduce greenhouse gas emissions. However, this technology was conceived nearly twenty years ago at Argonne National Laboratory as a low-cost CO{sub 2} source for enhanced oil recovery (EOR). The fundamental concept is to replace combustion air with oxygen diluted by recirculated CO{sub 2} from the flue gas. This eliminates N{sub 2}-CO{sub 2} separation, permitting more economical CO{sub 2} recovery than competing amine systems. A molar ratio of CO{sub 2}/O{sub 2} of {approx}3 is necessary to preserve the heat transfer performance and gas path temperatures, allowing this system to be applied as a retrofit.