Wet scrubber additive for simultaneous removal of oxides and metals from a gas
AssigneeThe United States of America as represented by the Administrator of the U.S. Environmental Protection Agency
InventorsNick D. Hutson, Ravi K. Srivastava, Renata Krzyzynska, Yongxin Zhao
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Abstract
A method for controlling multipollutant (e.g., SO2, NOx, Hg0 and Hg2+) emissions from a gas stream of a stationary combustion source, an apparatus for controlling multipollutant emissions, and a wet scrubber additive composition for controlling multipollutant emissions are disclosed.
Claims19
A process for removing SO2 and Hg0 vapor from a gas stream, comprising contacting the gas stream with an alkaline slurry and an oxidizing agent to remove the pollutants from the gas stream, and
- wherein the alkaline slurry contacts the gas stream at the same time the oxidizing agent contacts the gas.
An apparatus for scrubbing a gas stream comprising SO2 and at least one pollutant selected from the group consisting of NOx and Hg vapor, comprising:
- i) a holding tank for an alkaline slurry;
- ii) a holding tank for an aqueous solution of an oxidizing agent;
- iii) a spray tower having one or more contact zones;
- iv) one or more alkaline slurry introduction points along the spray tower;
- and
- v) one or more oxidizing agent introduction points along the spray tower, wherein the one or more alkaline slurry introduction points and the one or more oxidizing agent introduction points are positioned along the spray tower so that the gas stream is contacted with the alkaline slurry and oxidizing agent in a contact zone to obtain a reacted gas;
- vi) a forced oxidation device for treating alkaline slurry that has been in contact with the gas stream;
- and
- vii) an exhaust downstream from the contact zone for releasing the reacted gas, wherein the reacted gas emanating from the exhaust has been scrubbed of SO2 and at least one pollutant selected from the group consisting of NOx, and Hg0 vapor,
- and wherein x is 1 or 2.
Dependencies are inferred from the claim text.