Carboxylic acid activated dry calcium absorbent method for removing sulfur dioxide from a flue gas

• US 4,533,532 A
• Filed: 07/02/1984
• Issued: 08/06/1985
• Est. Priority Date: 08/28/1982
• Status: Expired due to Fees

• Current Assignee: Rheinisch-Westfalisches Elektrizitatswerk AG
• Original Assignee: Rheinisch-Westfalisches Elektrizitatswerk AG
• Inventors: Glaser, Wolfgang, Gebhard, Georg R. U., Hein, Klaus R. G.
• Primary Examiner(s): Thomas, Earl C.
• Application Number:
  US06/626,652
• Time in Patent Office: 400 Days
• Field of Search: 423/210, 423/240, 423/242 A, 423/242 R, 423/243, 423/244 A, 423/244 R, 252/190, 252/192, 44/1 R, 44/15 R, 44/4, 44/6, 110/341-345
• US Class Current: 423/242.3
• CPC Class Codes: B01D 53/508 by treating the gases with solids

Abstract

An absorbent for the dry removal of sulfur dioxide and other noxious and toxic components from a combustion flue gas which consists essentially of at least one finely divided alkaline-earth compound and an additive selected from the group which consists of at least one carboxylic acid or an alkali metal, alkaline-earth metal or ammonium salt thereof.

Claims

1. A method of removing sulfur dioxide and other noxious and toxic components from the flue gas of a power plant boiler which comprises the steps of:

(a) forming an absorbent by intimately mixing at least one alkaline-earth compound capable of absorbing sulfur dioxide with 0.1 to 10 mol % of an additive consisting of at least one absorbent-reactivity promoting carboxylic acid or an alkali metal, alkaline-earth metal or ammonium salt thereof;

(b) forming the flue gas by combustion of a fuel in a power plant boiler;

(c) contacting the flue gas after its formation in said boiler at an elevated temperature with absorbent formed in step (a) in a dry state and added to said flue gas independently of said combustion; and

(d) dry separating the absorbent after it has contacted the flue gas in step (c) from the remainder of the flue gas.

2. The method defined in claim 1 wherein said alkaline-earth compound is calcium carbonate.

3. The method defined in claim 2 wherein said absorbent contains 0.1 to 5 mol % of acetic acid.

4. The method of removing sulfur dioxide and other noxious and toxic components from a flue gas of a power plant boiler which comprises the steps of:

(a) forming an absorbent by intimately mixing at least one alkaline-earth compound capable of absorbing sulfur dioxide with 0.1 to 10 mol % of an additive consisting of acetic acid or an alkaline metal, alkaline-earth metal or ammonium salt thereof;

(b) contacting the flue gas after its formation by combustion and in a drying state to an elevated temperature with the absorbent formed in step (a); and

(c) dry separating the absorbent after it has contacted the flue gas in step (c) from the remainder of said flue gas.

5. The method defined in claim 4 wherein said alkaline-earth compound is calcium carbonate.