Method of treating waste gas by irradiation with electron beam

Patent 5041271 Issued on August 20, 1991. Estimated Expiration Date:

June 4, 2010. 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

Patent References

Process for utilizing collected material removed from effluent gas
Patent #: 3981815
Issued on: 09/21/1976
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Inventor: Zenty

Method of treating waste gas by irradiation
Patent #: 4294674
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Inventor: Aoki , et al.

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Patent #: 4323759
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Inventor: Pfeiffer

Inventors

Assignee

Ebara Corporation

Application

No. 532817 filed on 06/04/1990

US Classes:

423/235, Nitrogen or nitrogenous component204/157.3, Removing a component from normally gaseous mixture204/157.46, Nitrogen containing product produced204/157.49, Sulfur containing product produced204/158.2, Processes of purifying materials423/239.1Utilizing solid sorbent, catalyst, or reactant

Examiners

Primary: Heiler, Gregory A.

Attorney, Agent or Firm

Oblon, Spivak, McClelland, Maier & Neustadt

Foreign Patent References

3020301 DE. 02/12/1981
835934 JP. 03/12/1976
56-136629 JP. 10/12/1981
63-104635 JP. 08/12/1986
61-174924 JP. 08/12/1986

International Classes

C01B 021/00
B01J 008/00
B01D 053/00

Foreign Application Priority Data

1987-12-10 JP

Abstract

A waste gas containing sulfur oxides (SOx) and/or nitrogen oxides (NOx) is purified by leading the waste gas to a radiation irradiation zone, adding ammonia (NH3) to the waste gas before, during or after the irradiation, collecting the resulting by-product (ammonium sulfate and/or ammonium nitrate) by means of a dust collector, and releasing the purified waste gas into the atmosphere. The amount of NH3 to be added is selected so as to be smaller than an amount calculated from target desulfurization and denitrification efficiencies so that it is possible to reduce the leakage of ammonia despite variations in the composition of the waste gas. Further, an alkaline substance exclusive of ammonia is added to the waste gas either at a position between the electrostatic precipitator and the bag filter or at the upstream side of a reactor outlet or both or within a dust collector or at the upstream side thereof so that the pH of the collected by-product is adjusted to 6 or more, preferably 7 or more, thereby suppressing the adverse effects of sulfamic acid impurities.