Adsorption Properties of CFC and CFC Replacements on Activated Carbon Containing Introduced Ionic Fluoride and Chloride
✍ Scribed by Seiki Tanada; Naohito Kawasaki; Takeo Nakamura; Ikuo Abe
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 93 KB
- Volume
- 183
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
and unstable to heat; and (3) an adsorption type, soluble in Plasma technology has been available for the chlorofluorocarbon water and unstable to heat. (CFC) decomposition or etching of silicone. The adsorption prop-Chlorofluorocarbons (CFC) have been used in large quanerties of CFC (CFC113) and CFC replacements (HCFC141b, tities as solvents or detergents for a long time. CFCs have HCFC225cb, and 5FP) on several kinds of plasma-treated actian effect on ozone depth in the stratosphere and global vated carbons (P-ACs) prepared under different treatment gases warming, which led to the adoption of the 1987 Montreal were investigated using the adsorption isotherms, the limiting pore Protocol and Title VI of the 1990 Clean Air Act Amendment, volume (W o ) and the affinity coefficient and energy of adsorption ''Protecting Stratospheric Ozone.'' These agreements in-(BE o ) calculated by the Dubinin-Radushkevich plot, and the cluded major provisions for reducing the development of quality and kinds of introduced fluoride and chloride. The dissolved fluoride and chloride atoms were introduced to the surface CFC replacements. Because of the omnipresent use and benof activated carbon by CFC113, HCFC141b, and HCFC225cb, efits of CFCs, an expeditious search for safe CFC replacewhile the dissolved fluoride atoms were those from 5FP and tetraments to meet the legislative deadlines is of critical imporfluoromethane. The adsorbed amount of CFC and CFC replacetance. The Program for Alternative Fluorocarbon Toxicity ments, except for 5FP, on P-ACs was larger than that on U-AC. Testing (PAFT), an international group representing most The specific adsorption site on plasma-treated activated carbon of of the world's CFC producers, was established to evaluate the CFC and CFC replacements was the fluoride atoms which the health and environmental impact of CFC replacements. were introduced by plasma treatment. It is concluded that the CFC replacements are being developed and produced. CFCs plasma-treated activated carbon was suitable for the recovery of are the first-generation materials, hydrochlorofluorocarbons CFC and CFC replacements, because the adsorbed amount of (HCFCs) are the second generation, and hydrofluorocarbons CFC and CFC replacements was larger than that on untreated (HFCs) are the third generation. The effect of HCFCs on activated carbon, and the adsorbed CFC and CFC replacements on activated carbon were decomposed by the plasma treatment. ozone depletion and global warming is smaller than that of