Advanced Combustion

Near-Zero Emissions Oxy-Combustion Flue Gas Purification
Praxair Inc.
Project Number: DE-NT0005341

  Praxair oxy-combustion test equipment
Praxair oxy-combustion test equipment.

Praxair Inc. will develop a near-zero emissions flue gas purification technology for existing coal-fired power plants retrofit with oxy-combustion technology. Emissions of sulfur dioxide (SO2) and mercury (Hg) will be reduced by at least 99 percent, and nitrogen oxide (NOx) emissions will be reduced by greater than 90 percent without the need for wet flue gas desulfurization and selective catalytic reduction (SCR). Two separate processes are proposed depending on the sulfur content of the coal. For high-sulfur coal, SO2 and NOx will be recovered as product sulfuric acid and nitric acid, respectively, and Hg will be recovered as mercuric sulfate. For low-sulfur coal, SO2 will be converted to gypsum using a high-pressure activated carbon process. Any residual NOx will be treated in an SCR (<10 percent the size of a conventional SCR) and Hg will be captured on carbon for disposal. In both the options, atmospheric gases (oxygen, nitrogen, and argon) present with the CO2 will be separated and vented.

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  • For further information on this project, contact the NETL Project Manager, Morgan Mosser.