NOx, Hg, and SO2 removal using ammonia
AssigneePowerspan Corp.
InventorsJoanna L. Duncan, Christopher R. McLarnon, Francis R. Alix
Life of this patent
Estimating the term…
Abstract
A process and apparatus for removing SO2, NO, 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 Ammonium sulfate, a valuable fertilizer, can be withdrawn from the scrubbing solution.
Claims13
A process for removing SO2, NO, and NO2 from a gas stream comprising the steps of
- a. oxidizing at least a portion of NO in a gas stream to NO2 with an oxidizing means resulting in a mole ratio of SO2 to NO2 of at least 2.5 to 1, followed by
- b. scrubbing at least a portion of SO2, NO, and NO2 from the gas stream with a scrubbing solution
- comprising ammonia, and
- having a ph between 5 and 8, and
- c. removing at least a portion of any ammonia aerosols generated from the scrubbing step from the gas stream with an aerosol removal means.
A process for removing SO2, NO, NO2, and Hg from a gas stream comprising the steps of
- a. oxidizing at least a portion of the NO in a gas stream to NO2, and at least a portion of the Hg in a gas stream to HgO, with an oxidizing means, followed by
- b. scrubbing at least a portion of the SO2, NO, and NO2 from the gas stream with a scrubbing solution
- comprising ammonia, and
- having a pH between 5 and 8, and
- c. removing at least a portion of any ammonia aerosols generated from the scrubbing step, and HgO, from the gas stream with an aerosol removal means.
Dependencies are inferred from the claim text.