NOx, Hg, and SO2 removal using ammonia

Patent 6936231 Issued on August 30, 2005. Estimated Expiration Date:

December 6, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

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Inventors

Assignee

Powerspan Corp.

Application

No. 09683267 filed on 12/06/2001

US Classes:

423/235, Nitrogen or nitrogenous component423/242.1, Sulfur or sulfur containing component423/243.06, Ammonium compound reactant423/243.11, And subsequent reactive treatment to remove sulfur from spent reactant204/157.3Removing a component from normally gaseous mixture

Examiners

Primary: Silverman, Stanley S.
Assistant: Lish, Peter J

Attorney, Agent or Firm

Decker; Phillip E.

Foreign Patent References

4335867 DE 05/01/1995
WO-99/47268 WO 09/01/1999
WO-01/87464 WO 11/01/2001

International Class

B01D053/60

Abstract

A process and apparatus for removing SO2, O, and NO2 from a gas stream having the steps of oxidizing a portion of the NO in the flue gas stream to NO2, scrubbing the SO2, NO, and NO2 with an ammonia scrubbing solution, and removing any ammonia aerosols generated by the scrubbing in a wet electrostatic precipitator. The process can also remove Hg by oxidizing it to HgO and removing it in the wet electrostatic precipitator. Ammonium sulfate, a valuable fertilizer, can be withdrawn from the scrubbing solution.