IP Library Granted Patent US 7,727,309
Granted Patent B2
US 7,727,309 · App. 12/002,449 · Granted Jun 1, 2010

Carbon dioxide absorbent

Assignee: Allied Healthcare Products, Inc.
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Quick Facts
Patent No.
US 7,727,309
App. No.
12/002,449
Granted
Jun 1, 2010
Kind
B2
Abstract

A carbon dioxide absorbent suitable for use in anesthesiology during low flow or closed circuit made of from 70 to 90% hydrated lime, from 0.1 to 17% of lithium hydroxide or its precursor, or a combination thereof, and from 5 to 25% water, wherein the absorbent provides low Compound A by-product, and high absorbency.

Claims (19)

1. A carbon dioxide absorbent formulation comprising from about 70 to 90 wt. % hydrated lime essentially free of potassium hydroxide and sodium hydroxide; from about 0.1 to 17 wt. % lithium hydroxide or its precursor or a combination thereof; and from about 5 to 25 wt. % water.

2. The absorbent of claim 1 , wherein the lithium hydroxide precursor is selected from the group consisting of lithium hydroxide, lithium hydroxide monohydrate, lithium chloride, lithium chloride hydrate, lithium carbonate, and lithium silicate and a combination thereof.

3. The absorbent of claim 2 , further comprising a hardening agent from about 0.1 to 10.0 wt. %.

4. The absorbent of claim 3 , wherein the hardening agent is selected from the group consisting of calcium chloride, magnesium chloride, calcium sulfate, and lithium silicate, and a combination thereof.

5. The absorbent of claim 1 , wherein the absorbent also contains an alkali halide or an alkaline earth halide from about 0.1 to 5.0 wt. %.

6. The absorbent of claim 1 , which contains from about 0.1 to 5.0 wt. % calcium chloride.

7. The absorbent of claim 2 , which contains from about 0.5 to 5.0 wt. % glycerol.

8. The absorbent of claim 1 , wherein the lithium hydroxide precursor is lithium hydroxide and/or lithium chloride from about 0.1 to 17 wt. % and the absorbent contains calcium chloride from about 0.1 to 5.0 wt. %.

9. A method of making a carbon dioxide absorbent comprising mixing from about 70 to 90 wt. % hydrated lime, based on the dried absorbent, essentially free of potassium hydroxide and sodium hydroxide; and from about 0.1 to 17 wt. % lithium hydroxide or its precursor or any combination thereof, based on the dried absorbent, in an aqueous suspension or solution, to form a paste, and drying the paste to form the absorbent, wherein the final moisture content of the absorbent is from about 5 to 25 wt. % water.

10. The method of claim 9 , wherein indicating dyes, hardening agents, processing agents, and humectants arc added to the absorbent before drying.

11. A method of absorbing carbon dioxide in anesthesia gas comprising contacting the anesthesia gas containing carbon dioxide with a carbon dioxide absorbent formulation comprising from about 70 to 90 wt. % hydrated lime essentially free of potassium hydroxide and sodium hydroxide; from about 0.1 to 17 wt. % lithium hydroxide or its precursor or a combination thereof; and from about 5 to 25 wt. % water, to remove carbon dioxide from the anesthesia gas.

12. The method of claim 11 , wherein the anesthesia agent is selected from the group consisting of sevoflurane, desflurane, isoflurane, halothane, and enflurane and a combination thereof.

13. The method of claim 11 , wherein the lithium hydroxide precursor comprises at least one selected from the group comprising lithium hydroxide, lithium hydroxide monohydrate, lithium chloride, lithium chloride hydrate, lithium carbonate, and lithium silicate, and a combination thereof.

14. The method of claim 11 , wherein the absorbent contains at least one hardening agent selected from the group consisting of calcium chloride, magnesium chloride, calcium sulfate, and lithium silicate.

15. The method of claim 11 , wherein the absorbent contains from about 0.1 to 5.0 wt. % of an alkali halide or an alkaline earth halide or a combination thereof.

16. The method of claim 11 , wherein the absorbent contains from about 0.1 to 5.0 wt. % calcium chloride.

17. The method of claim 11 , wherein the absorbent contains from about 0.5 to 5.0 wt. % glycerol.

18. The method of claim 11 , wherein the lithium hydroxide precursor is lithium hydroxide and/or lithium chloride from about 0.1 to 17 wt. %, and the absorbent contains calcium chloride from about 0.1 to 5.0 wt. %.

19. The method of claim 11 , wherein the absorbent contains from 0.1 to 3.0 wt. % of indicator dye.

Assignments (4)
RELEASE OF SECURITY INTEREST Recorded Mar 13, 2024
From: STERLING COMMERCIAL CREDIT, LLC
To: ALLIED HEALTHCARE PRODUCTS, INC.
Reel/Frame 066754/0340 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 13, 2024
From: ALLIED HEALTHCARE PRODUCTS, INC.
To: ALLIED MEDICAL, LLC
Reel/Frame 066754/0790 →
SECURITY INTEREST Recorded Mar 14, 2023
From: ALLIED HEALTHCARE PRODUCTS, INC.
To: STERLING COMMERCIAL CREDIT, LLC
Reel/Frame 062981/0330 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 16, 2008
From: ROBERTSON, JOHN; BENITEZ, CAROLS A; WOERNER, DOUGLAS L; VISSCHER, CHANNON
To: ALLIED HEALTHCARE PRODUCTS, INC.
Reel/Frame 020812/0652 →
Continuity (3)
Provisional Application 6087721800 · Dec 26, 2006
Provisional Application 6093303200 · Jun 4, 2007
Related Publication 20080210091A1 · Sep 4, 2008