Absorption of sulfur oxides from flue gas

Patent · Thu Oct 26 04:00:00 EDT 1972

OSTI ID:7355974

Grantham, L F; Gehri, D C; Katz, B

A closed-cycle process is described which is capable of removing, in a single spray-drying step, at least 90 percent of a sulfur oxide impurity from a hot waste gas. The method consists of contacting the hot sulfur oxide-containing waste gas at a temperature of at least 90/sup 0/C in a single spray-drying step with an aqueous scrubbing medium containing between 2 and 40 wt.percent of an absorbent selected from the group consisting of alkali metal carbonate, alkali metal bicarbonate, and mixtures of alkali metal carbonate and bicarbonate to form alkali metal sulfate and sulfite; recovering the resultant reaction product as a flowable, dry powder mixture not requiring further drying, the mixture containing from 20 to 85 wt. percent alkali metal sulfite and sulfate and from 15 to 80 wt.percent alkali metal carbonate and bicarbonate; the reacting mixture in the molten state with a carbonaceous reducing agent under reducing conditions to convert sulfite and sulfate to sulfide while supplying a controlled amount of a source of gaseous oxygen to the reaction to provide internal heat generation to melt the mixture and maintain it in the molten state; recovering a molten reaction product of alkali metal sulfide and carbonate; dissolving this reaction product in water to form an aqueous solution; and reacting the aqueous solution with a carbon dioxide-yielding material to form hydrogen sulfide gas as a recoverable product and regenerate alkali metal bicarbonate and carbonate for recirculation in the process.

• Assignee: Rockwell International Corp.
• Patent Number(s): US 3932587
• OSTI ID: 7355974
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200202* -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions
AIR POLLUTION
CHALCOGENIDES
CHEMICAL REACTIONS
DESIGN
DESULFURIZATION
DRYING
EQUIPMENT
FLUE GAS
GASEOUS WASTES
OPERATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION
POLLUTION CONTROL EQUIPMENT
POWER PLANTS
REMOVAL
SPRAY DRYING
SULFUR COMPOUNDS
SULFUR OXIDES
THERMAL POWER PLANTS
WASTES