Method for scrubbing pollutants from an exhaust gas stream
This patent describes a method of treatment of an exhaust gas stream containing as pollutants at least one of the acidic oxides of sulfur, nitrogen, carbon, and halogens and acidic halogen compounds, whose temperature exceeds the dew point of the gas, for producing scrubbed exhaust and useful or benign by-products. It comprises: providing a basic aqueous slurry of ash, the ash containing alkali and alkaline earth metal salts, contacting the exhaust gas stream with the slurry in a manner to scrub the exhaust gas stream and to cause the pollutants therein to react with the water in the slurry to produce acids, allowing the acids to react with any oxides, hydroxides and carbonates of alkali and alkaline metal salts in the slurry, thereby to produce a solution with soluble alkali metal salts and a precipitate of any insoluble alkali and alkaline earth metal salts comprising at least one of halogen compounds, carbonate, sulfate, sulfite, nitrate, and nitrite of calcium, magnesium, potassium and sodium in the slurry, recovering the precipitate from the solution, evaporating the solution freed of the precipitate, recovering in solid form any soluble alkali and alkaline earth metal salts present in said solution, and expelling the scrubbed exhaust gas stream.
- Assignee:
- Passamaquoddy Technology Ltd. Partnership, Portland, ME (United States)
- Patent Number(s):
- US 5100633; A
- Application Number:
- PPN: US 7-604322
- OSTI ID:
- 5199809
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
330700* -- Advanced Propulsion Systems-- Emission Control
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION CONTROL
ALKALINE EARTH METALS
ASHES
CARBON COMPOUNDS
CARBON OXIDES
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CHALCOGENIDES
COMBUSTION PRODUCTS
CONTROL
ELEMENTS
EQUIPMENT
EXHAUST GASES
FLUE GAS
FLUIDS
GASEOUS WASTES
GASES
HALOGEN COMPOUNDS
MANAGEMENT
MATERIALS RECOVERY
METALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTANTS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
PROCESSING
REMOVAL
RESIDUES
SCRUBBING
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES