A continuing search for new refrigerants

Journal Article · Sun Dec 01 04:00:00 EST 1996 · CHEMTECH

OSTI ID:419608

Seikya, Akira; Misaki, Susumu

The destruction of the ozone layer by chlorofluorocarbons (CFCs) is the first environmental issue to be considered on a global scale. It thus serves as a model for international environmental restoration efforts, showing how effective an international agreement can be in protecting the environment. One of the most important technological measures in ozone layer protection is developing alternative chemicals for CFCs that have low impact on the environment and a long useful life. Because of CFCs` superior physical and chemical properties -- as well as stability, safety, and low toxicity -- they have been used in refrigerants, foaming agents, and cleaning solvents. However, CFCs survive in the atmosphere for a long time, reach the stratosphere, and release chlorine atoms on exposure to ultraviolet radiation. Given that increased chlorine concentration in the stratosphere is one of the main causes of ozone layer depletion, CFC production was terminated in developed countries by the end of 1995. The properties desired in alternatives to CFCs dictate the feasibility (or unfeasibility) of using certain chemicals as constituent compounds. Compounds that do not deplete the ozone layer do not contain chlorine, bromine, or iodine; therefore, desirable alternative compounds would not contain these chemicals. Because the properties of alternative compounds should be similar to those of CFCs, fluorinated compounds are likely candidates. Because the compounds should decompose in the atmosphere within a few years after their useful life has ended, they must contain hydrogen. However, too many hydrogen atoms increase flammability. Incidentally, the presence of fluorine has no effect on ozone layer depletion. Although ethers, alcohols, tertiary amines, sulfur(VI) compounds, and silicon compounds are being considered as stable compounds containing heteroatoms, the authors limit their discussion to certain fluorinated ethers as possible CFC alternatives.

• OSTI ID: 419608
• Journal Information: CHEMTECH, Journal Name: CHEMTECH Journal Issue: 12 Vol. 26; ISSN CHTEDD; ISSN 0009-2703
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION ABATEMENT
CHLOROFLUOROCARBONS
ENVIRONMENTAL EFFECTS
FLUORINATED ALIPHATIC HYDROCARBONS
MATERIAL SUBSTITUTION
OZONE
REFRIGERANTS