Desulfurization process uses electrodialysis

Journal Article · Mon Sep 19 00:00:00 EDT 1977 · Chem. Eng. News; (United States)

OSTI ID:7219367

A method for stack gas desulfurization based on bipolar membrane technology is described. The process is a regenerative type. Sulfur dioxide is removed from the flue gas by scrubbing the gas with a highly alkaline solution of sodium sulfide/sodium hydroxide/sodium carbonate. In the absorber, sulfur dioxide is converted to sodium bisulfite. Sodium sulfate also is formed in the absorber as a result of oxidation of sulfite species, the research workers explain. Spent absorber solution is filtered to remove particulate and cooled to about 110/sup 0/F before being fed into the electrodialysis section for regeneration. The water splitting section consists of two identical parallel trains, each of which contains three stages. Acid solution from the splitters, consisting of a sodium sulfate solution saturated with sulfur dioxide, is transferred to a stripper, where the solution is heated by direct injection of steam. Sulfur dioxide from the stripper, combined with the sulfur dioxide from the recirculation tanks, then can be further processed to sulfur or sulfuric acid or can be liquefied. Bottoms from the stripper consist of a nearly pure solution of sodium sulfate. Most of it is recycled to the absorber, but sulfate must be removed in an amount equivalent to that formed by oxidation in the absorber. This is done by feeding some of the bottoms to an evaporator where water is removed. Sodium sulfate is filtered and dried. Sodium values lost with the sulfate are made up through addition of sodium carbonate to the absorber scrubbing solution.

• OSTI ID: 7219367
• Journal Information: Chem. Eng. News; (United States), Vol. 55:38
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
FLUE GAS
DESULFURIZATION
SULFUR DIOXIDE
REMOVAL
COAL
COMBUSTION PRODUCTS
ELECTRODIALYSIS
FOSSIL-FUEL POWER PLANTS
RECYCLING
SCRUBBING
SODIUM CARBONATES
SODIUM HYDROXIDES
SODIUM SULFIDES
WATER
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATES
CHALCOGENIDES
CHEMICAL REACTIONS
DIALYSIS
ENERGY SOURCES
FOSSIL FUELS
FUELS
GASEOUS WASTES
HYDROGEN COMPOUNDS
HYDROXIDES
OXIDES
OXYGEN COMPOUNDS
POWER PLANTS
SEPARATION PROCESSES
SODIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
SULFUR OXIDES
THERMAL POWER PLANTS
WASTES
010800* - Coal
Lignite
& Peat- Waste Management