# US 4,382,011 A · Composition of matter useful in flue gas desulfurization process

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- Number: US 4,382,011 A
- Document ID: US4382011A
- Status: Granted
- Kind: A
- Application number: 06/207,916
- Filed: 1980-11-18
- Granted: 1983-05-03
- Earliest claimed: 1976-05-20
- Inventors: David Lurie
- Web page: https://patentgrep.com/patent/US4382011A

## CPC

- B01D 53/501: {by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound}
- C01B 17/0482: {with carbon or solid carbonaceous materials}
- C01B 17/60: Isolation of sulfur dioxide from gases
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

Flue gas having a content of sulfur dioxide is passed upwardly through a scrubbing tower against a descending flow of recycled aqueous sodium aluminate-sodium hydroxide liquor. The sulfur dioxide in the gas is converted to sodium and aluminum sulfates and sulfites and the liquor removes any fly ash present in the gas. Underflow is continuously discharged from the tower and is sent to an evaporator for removal of excess water. Make-up solutions of sodium sulfate and aluminum sulfate are added, as necessary. Carbonaceous reducing agent is added to the discharge from the evaporator. The mixture is continuously fed into a reducing furnace where the sulfates and sulfites are reduced to sulfides. The product of the furnace (molten sodium and aluminum sulfides) is charged into a continuous hydrolyzer. Hydrogen sulfide is evolved and collected, and, if desired, its sulfur content is converted to elementary sulfur. The underflow from the hydrolyzer is filtered. The filtrate is aqueous sodium aluminate-sodium hydroxide solution which is recycled to the scrubbing tower.

## Claims

### Claim 1

A fluid molten mixture of aluminum sulfide and sodium sulfide in 1:1 to 1:2 Al.sub.2 O.sub.3 :Na.sub.2 O equivalent molar ratio.

### Claim 2 (depends on 1)

A fluid molten mixture according to claim 1, wherein said ratio is 1:1.1.