Flat sheet CO.sub.2 sorbent

• US 5,681,503 A
• Filed: 06/07/1995
• Issued: 10/28/1997
• Est. Priority Date: 11/08/1990
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Birbara, Philip J., Nalette, Timothy A.
• Primary Examiner(s): Gibson, Sharon
• Assistant Examiner(s): Fee, Valerie
• Application Number:
  US08/472,104
• Time in Patent Office: 874 Days
• Field of Search: 252/193, 252/192, 252/190, 423/430, 423/232, 502/520, 244/163
• US Class Current: 252/192
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28033 Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 20/3433 of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y10S 502/52 Suppressed side reactions

Abstract

A technique for preparing a flat sheet, high capacity CO₂ sorbent and sorbent assembly is disclosed. The sorbent, which is in the form of a sheet, can be a metal oxide/alkali metal carbonate regenerable sorbent, while the sorbent assembly is comprised of the sheet sorbents located between constraining means and gas flow passages.

Claims

1. A method for removing CO₂ from a gaseous stream, which comprises:

passing the gaseous stream through a sheet sorbent assembly having a CO₂ reactive silver oxide/alkali metal carbonate sheet sorbent essentially free of inert materials, constraining means for constraining said sheet sorbent, and means for providing gas flow passages to allow said gaseous stream to contact said sheet sorbent as said gaseous stream passes through said sheet sorbent assembly, and flowing said gaseous stream through said means for providing gas flow passages, wherein the CO₂ diffuses into said sheet sorbent, the alkali metal carbonate reacts with the diffused CO₂ to form alkali metal bicarbonate, and the reactive metal oxide reacts with the formed alkali metal bicarbonate to form metal carbonate and regenerated alkali metal carbonate.

2. A method for removing CO₂ from a gaseous stream as recited in claim 1 wherein said alkali metal carbonate is selected from the group consisting of cesium carbonate, potassium carbonate, sodium carbonate, and mixtures thereof.

3. A method for removing CO₂ from a gaseous stream as recited in claim 1 wherein said reactive silver oxide/alkali metal carbonate sheet sorbent has between about 60 wt % and 95 wt % reactive metal oxide and between about 5 wt % and 40 wt % alkali metal carbonate.

4. A method for removing CO₂ from a gaseous stream as recited in claim 3 wherein said reactive silver oxide/alkali metal carbonate sheet sorbent has a thickness between about 0.01 inches and about 0.25 inches.

5. A method for removing CO₂ from a gaseous stream as recited in claim 1 further comprising heating said formed metal carbonate to desorb CO₂ wherein said formed metal carbonate is converted to reactive metal oxide.

6. A method for removing CO₂ from a gaseous stream as recited in claim 5 wherein said sheet sorbent is heated to temperatures between about 160°

C. and about 220°

C. and said sheet sorbent being essentially free of dusting for greater than 100 regeneration cycles.