Chemistry of inorganic compounds – Modifying or removing component of normally gaseous mixture – Nitrogen or nitrogenous component
Reexamination Certificate
2000-10-18
2002-06-04
Griffin, Steven P. (Department: 1754)
Chemistry of inorganic compounds
Modifying or removing component of normally gaseous mixture
Nitrogen or nitrogenous component
C252S192000, C422S177000, C423S210000, C423S239100
Reexamination Certificate
active
06399036
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the use of a combination of alkali metal hydroxides and alkaline-earth metal hydroxides as a scavenging material for cyanide gas. In particular, the present invention relates to a method and means for either filtering out cyanide gas or detoxifying areas contaminated with cyanide using Sodalime or Baralyme™.
2. Background Information
Hydrogen cyanide gas (HCN) is a potent metabolic poison that acts by blocking cellular aerobic metabolism. Even brief exposures to HCN can be rapidly fatal in humans. Human exposure to HCN occurs upon inhalation of the smoke from fires, as well as from extensive cyanide use in industries such as metal finishing, fishing, and commercial gold mining. HCN gas is also a significant weapon in chemical warfare due to its potent ability to suppress cellular respiration.
Although an antidote exists, the rapid toxicity of cyanide gas often prevents effective treatment. The lethal exposure level for inhaled cyanide is 100 ppm. It is thus preferable to limit exposure to this poison.
The military standard for a portable air purification device is the C2A1 canister, currently produced by Racal Filter Technologies, Inc. for the U.S. Army. The C2A1 canister comprises a metal body which incorporates a high efficiency particulate filter, and a bed of activated impregnated carbon. Through physical adsorption with the activated charcoal, organic vapors such as nerve agents, mustard gases, and chloropicirin are removed. The activated carbon of the C2A1 canister is impregnated with salts of copper, zinc, molybdenum, and silver along with the organic chemical triethylenediamine. This mixture removes gases such as cyanogen chloride, hydrogen cyanide, phosgene and arsine.
A need however, continues to exist for a compound and/or compounds exhibiting improved scavenging of cyanide. In addition, activated charcoal has several properties, such as production of poisonous gases on combustion, which makes it unsuitable as a general spray or absorbent for cyanide-contaminated areas. Thus, a need also exists for a compound and/or compounds that is suitable as a general spray or absorbent for cyanide-contaminated areas.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a filtering system for cyanide gas.
It is a further object of the present invention to provide a general scavenging material for detoxification of contaminated areas.
It is a still further object of the present invention to filter out cyanide gas with a portable, individual air purifier device such as a gas mask.
It is yet another object of the present invention to provide a spray or absorbent for cyanide contaminated areas.
Some of the above objects are obtained by a process for removing cyanide containing gas from air. The process includes providing a cyanide scavenging material, contacting the air with the cyanide scavenging material, and absorbing the cyanide containing gas with the cyanide scavenging material. The cyanide scavenging material is a combination comprising Calcium Hydroxide, Barium Hydroxide, and Potassium Hydroxide.
Others of the above objects are obtained by a composition of matter for removing cyanide containing gas from air. The composition is a combination of Sodalime with a composition that includes 73% Calcium Hydroxide, 11% Barium Hydroxide, and 5% Potassium Hydroxide.
Some of the above objects are also obtained by an apparatus for removing cyanide containing gas from air. The apparatus includes a cyanide scavenging material and a means for contacting the air with the cyanide scavenging material. The cyanide scavenging material is a combination that includes Calcium Hydroxide, Barium Hydroxide, and Potassium Hydroxide.
REFERENCES:
patent: 4201751 (1980-05-01), Holter et al.
patent: 4206186 (1980-06-01), Holter et al.
patent: 4271133 (1981-06-01), Tellis
patent: 4313916 (1982-02-01), Jones, Jr. et al.
patent: 5169615 (1992-12-01), Jennings et al.
patent: 5602295 (1997-02-01), Abel et al.
patent: 5634426 (1997-06-01), Tomlinson et al.
patent: 5690101 (1997-11-01), Kutta
patent: 26 47 520 (1978-04-01), None
patent: 615346 (1949-01-01), None
A. Harrestrup Andersen, “Adsorption Power of Charcoal in Aqueous Solutions”, Acta Pharmacologica vol. 2, 69-74 (1946).
Simon J. Smith, PhD. The C2A1 Canister from Racal Filter Technologies Inc. 1997.
Lambert et al., The Efficacy of Superactivated Charcoal in Treating Rats Exposed to a Lethal Oral Dose of Potassium Cyanide; Annals of Emergency Medicine 17:6, 595-598, Jun. 1988.
Moss Jonathan
Roizen Michael
Tung Avery
LandOfFree
Use of solid hydroxides as scavenging materials for cyanide gas does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Use of solid hydroxides as scavenging materials for cyanide gas, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of solid hydroxides as scavenging materials for cyanide gas will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2898975