The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 1998
Filed:
Oct. 29, 1996
Hisaji Nakano, Ube, JP;
Nobuhiko Matsuoka, Ube, JP;
Tetsuo Ueda, Ube, JP;
Shinsuke Nakagawa, Ube, JP;
Central Glass Company, Limited, Yamaguchi, JP;
Abstract
The present invention relates to a method for decomposing any of chlorocarbons, chlorofluorocarbons, perfluorocarbons and SF.sub.6 contained in a gas. This method includes the step of bringing the gas into contact, at a temperature of at least 300.degree. C., with a first mixture consisting essentially of 0.05-40 wt % of potassium hydroxide and at least one compound selected from the group consisting of alkali-earth-metal oxides and alkali-earth-metal hydroxides, for decomposing the at least one halide compound. When the halide compound-containing gas further contains oxygen, this gas may be brought into contact, at a temperature of at least 500.degree. C., with at least one first substance selected from the group consisting of active carbon, iron powder and nickel powder, for removing the oxygen from the gas, prior to the halide compound decomposition. When the halide compound-containing gas still further contains a strong oxidizing gas (e.g., fluorine), this gas may be brought into contact, at a temperature of at least 300.degree. C., with at least one second substance selected from the group consisting of Si, Ti, Ge, W, Mo, Fe, Mn, Co, Zn, Sn, B, Zr and compounds of these elements, except oxides of these elements, such that the oxidizing gas turns into a compound that is not reactive with the at least one first substance. According to this method, it is possible to decompose halide compounds contained within a gas, using a smaller equipment, at a lower temperature, as compared with conventional methods.