Carbon Dioxide Capture and Transportation Options in the Illinois Basin

U.S. DOE Contract: DE-FC26-03NT41994Ope

Applications of oxygen for NOx control and CO2 capture in coal-fired power plants

Two promising combustion modification approaches applicable to pulverized coal fired boilers are presented: "Oxygen-Enriched Combustion" (OEC) for NOx control and "Oxy-Combustion" (PC-OC) for CO2 capture. Oxygen-enriched air rather than air is used as an oxidizer in the OEC technology. Unlike flue gas treatment technologies, OEC directly impacts the NOx formation process by significantly reducing the conversion of coal bound nitrogen to NOx. Pilot-scale and full-scale tests have shown 20 to 30% NOx reduction from an optimized staged-air baseline. In addition to the overall cost competitiveness and the reduced capital requirements, other significant advantages of the O2-enriched technology vs. existing low NOx technologies are presented. The PC-OC technology is shown as a cost-effective technology for CO2 capture from existing or new coal-fired power plants. Pure oxygen diluted in recycled flue gases is used as an oxidizer. The process has been successfully demonstrated and extensively characterized at pilot-scale level (1.5 MWt). The tests have shown substantial benefits of the PC-OC technology, in terms of NOx reduction (60-70% from air-baseline), overall plant efficiency, etc. The cost effectiveness of this capture technology compared to competitive amine scrubbing technology was investigated. The cost of CO2 avoided was around $36/ton for the new PC-OC cases, about$48/ton on a retrofit PC-OC case, which is about 25 to 40% cheaper than the amine scrubbing system. Those numbers were calculated for sub-critical units and include the cost of CO2 compression up to 80 bar.

APPLICATIONS OF OXYGEN FOR NO x CONTROL AND CO 2 CAPTURE IN COAL-FIRED POWER PLANTS by

ing com bus tion mod i fi ca tion ap proaches ap pli ca ble to pul ver-ized coal fired boil ers are pre sented: “Ox y gen-En riched Com bus tion” (OEC) for NOx con trol and “Oxy-Com bus tion ” (PC-OC) for CO2 cap ture. Ox y gen-en riched air rather than air is used as an ox i dizer in the OEC tech-nol ogy. Un like flue gas treat ment tech nol o gies, OEC di rectly im pacts the NOx for ma tion pro cess by sig nif i cantly re duc ing the con ver sion of coal bound ni tro gen to NOx. Pi lot-scale and full-scale tests have shown 20 to 30 % NOx re duc tion from an op ti mized staged-air base line. In ad di tion to the over all cost com pet i tive ness and the re duced cap i tal re quire ments, other sig nif i cant ad van tages of the O2-en riched tech nol ogy vs. ex ist ing low NOx tech nol o gies are pre sented. The PC-OC tech nol ogy is shown as a cost-ef fec tive tech nol ogy for CO2 cap-ture from ex ist ing or new coal-fired power plants. Pure ox y gen di luted in re cy cled flue gases is used as an ox i dizer. The pro cess has been suc cess fully dem on strated and ex ten sively char ac ter ized at pi lot-scale level (1.5 MWt). The tests have shown sub stan tial ben e fits of the PC-OC tech nol ogy, in terms of NOx re duc tion (60-70 % from air-base line), over all plant ef fi ciency, etc. The cost ef fec tive ness of this cap ture tech nol ogy com pared to com pet i tive amine scrub bing tech nol ogy was in ves ti gated. The cost of CO2 avoided was around $36/ton for the new PC-OC cases, about$48/ton on a ret ro fit PC-OC case, which is about 25 to 40 % cheaper than the amine scrub bing sys tem. Those num bers were cal cu lated for sub-crit i cal units and in clude the cost of CO2 com pres sion up to 80 bar