Recovery of concentrated H/sub 2/S from SO/sub 2/ contained in flue gas

Patent · Tue May 13 04:00:00 EDT 1986

OSTI ID:5692579

Miller, R

The process consists of: (a) contacting the gas with a recycled, aqueous, alkaline reaction medium being supplied from the separated solution obtained in step (d); (b) adding, in the substantial absence of air, sufficient sodium carbonate formed in step (g) to the reaction medium formed in step (a) to react with the dissolved sodium pyrosulfite to form a slurry of solid sodium sulfite suspended in the resulting aqueous, alkaline reaction medium and concentrated, gaseous carbon dioxide; (c) separating the concentrated, gaseous carbon dioxide and recycling it to step (i); (d) separating solid sodium sulfite from the aqueous, alkaline reaction medium and recycling the reaction medium to step (a); (e) reducing the separated sodium sulfite to sodium sulfide; (f) mixing the sodium sulfide formed in step (e) with water; (g) reacting, in the substantial absence of air, the sodium sulfide contained in the mixture formed in step (f) with particles of solid sodium bicarbonate from step (j) at a temperature sufficiently high to form a slurry of solid sodium carbonate suspended in a saturated sodium carbonate solution and a gas mixture consisting primarily of water vapor and hydrogen sulfide and recovering the hydrogen sulfide; (h) recycling part of the solid sodium carbonate formed in step (g) to step (b); (i) adding the remainder of the sodium carbonate formed in step (g) to a saturated sodium bicarbonate solution and carbonating the resulting mixture with carbon dioxide formed in step (b) to form a slurry of solid particles of sodium bicarbonate dispersed in the solution; and (j) separating particles of sodium bicarbonate from the slurry formed in step (i) and recycling the separated particles to step (g).

• Assignee: NOV; NOV-85-014206; EDB-86-130320
• Patent Number(s): US 4588567
• OSTI ID: 5692579
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION CONTROL
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONATES
CHALCOGENIDES
CHEMICAL REACTIONS
CONTROL
DESULFURIZATION
DISPERSIONS
FLUE GAS
GASEOUS WASTES
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
MIXING
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PARTICLES
POLLUTION CONTROL
RECYCLING
REMOVAL
SLURRIES
SODIUM CARBONATES
SODIUM COMPOUNDS
SODIUM SULFIDES
SULFIDES
SULFITES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUSPENSIONS
TEMPERATURE DEPENDENCE
WASTES
WATER