Method for removing nitrogen oxides from a gas stream
A gas stream containing nitrogen oxides, such as the tail gas from a nitric acid plant, is treated to reduce the nitrogen oxides content thereof. The method results in the production of an aqueous solution of ammonium nitrate. In a liquid-gas contact apparatus, the gas stream is first reacted, under steady state conditions, in counter-current flow, with an aqueous solution of ammonium nitrate at a pH of about 0.01 to about 0.5. The gas stream is then further reacted with an aqueous solution of ammonium nitrate at a pH of about 8.1 to about 8.5; and thereafter with water, preferably slightly acidified to a pH of 0 to 6.5. The resulting gas stream of reduced nitrogen oxides content may be safely discharged to the atmosphere without causing air pollution, the nitrogen oxides content being below imposed standards.
- Assignee:
- Goodpasture Inc
- Patent Number(s):
- US 4219534
- OSTI ID:
- 7011072
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
424000* -- Engineering-- Pollution Control Equipment-- (1980-1989)
AIR POLLUTION CONTROL
AMMONIUM COMPOUNDS
AMMONIUM NITRATES
CHALCOGENIDES
CHEMICAL PLANTS
CHEMICAL REACTIONS
DENITRIFICATION
GASEOUS WASTES
INDUSTRIAL PLANTS
NITRATES
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POLLUTION CONTROL
REMOVAL
WASTES