CFC refrigerants

Note that several CFC refrigerants are included, although they are being phased-out and replaced by more environmentally safe refrigerants. These are left in the table at this time because they have been such common/prominent refrigerants in industrial applications. 

Parts containing chlorofluorocarbons (CFCs) (refrigeration cycle in refrigerators/insula-tion materials)... 

As CFC refrigerants are phased out of production, their replacements in the cold storage applications will be HFC candidates such as R-134a, R-404A, and R-507. The use of ammonia, which is considered an environmentally benign refrigerant, will continue to play an ever-increasing role. 

Lastly, as CFC refrigerant fluids are being phased out of refrigeration systems and other refrigerant fluids substituted, the reactivity of the substitute material with process materials must be evaluated. 

Cyclopentane is widely used in producing non-CFC refrigerators, freezers and cold storage and tubing insulating materials. 

Studies of the CFC refrigerant s ozone depletion and its effect on the ozone layer and global warming have reached such serious conclusions that both national and international accords are in place to protect the environment (52, 71, 74). 

Even when CFC production is completely halted, CFCs still will be released to the atmosphere when the equipment in which they were used, such as refrigerators and air conditioners, are junked and the fluid systems are breached. Some municipalities (e.g., the city of Cambridge, Massachusetts) now have ordinances requiring the recovery of CFC refrigerants from appliances and air conditioners before the appliances are discarded. 

Absorption chillers use heat as the primary source of energy for driving an absorption refrigeration cycle. These chillers require very little electric power (0.02 kW/ton) compared to electric chillers that need 0.47-0.88 kW/ton, depending on the type of electric chiller. Absorption chillers have fewer and smaller moving parts and are quieter during operation than electric chillers. These chillers are also environment-friendly in that they use non-CFC refrigerants. 

Lorentzen, G., and J. Petterson. 1992. New possibilities for non-CFC refrigeration. In Proceedings of the IIR International Symposium on Refrigeration, Energy, and Environment, Trondheim, Norway, 147-163. 

By the time of the Montreal Protocol on Substances that Deplete the Ozone Layer (the "Montreal Protocol"), it was widely recognised that chlorine containing refrigerants, particularly CFCs, were implicated in the depletion of the Earth s ozone layer. With the establishment of the Montreal Protocol and the subsequent legislation passed in participating countries, there came a need in the refrigeration industry to find suitable replacements for CFC refrigerants as quickly as possible. HCFCs were subsequently added to the list of substances to be phased out under the Montreal Protocol in 1992. 

Chlororocarbon (CFC) refrigerants are inherently safer with respect to fire, explosion, and acute toxic hazards when compared to alternative refrigerants such as ammonia, propane, and sulfur dioxide. However, they are believed to cause long term environmental damage because of stratospheric ozone depletion. 

In many cases, it is not readily apparent how the potential impacts from different hazards can be translated into some common scale or measure. For example, how do you compare long term environmental damage and health risks from use of CFC refrigerants to the immediate risk of fatality from the fire, explosion, and toxicity hazards associated with many alternative refrigerants This question does not have a "right answer. It is not really a scientific question, but instead it is a question of values. Individuals, companies, and society must determine how to value different kinds of risks relative to each other, and base decisions on this evaluation. 

Recycling of used CFC refrigerants was introduced in 1986 - 87. After collection by dealers, the essential processing steps are mechanical purification and distillation. 

During the time CFCs were in common use, little effort was made to prevent them from escaping into the atmosphere. For example, if your automobile air conditioner needed repair, the common practice was to vent all of the CFC refrigerant into the atmosphere before any work was done. In fact, most of the CFCs ever manufactured have probably been released into the atmosphere. 

D. O Shaughnessey, Flammability of R134a, R22, and R123 in Chlorine, Chlorine Institute CFC Refrigerant Alternatives Seminar, New Orleans, LA (1993). 

The heat pump dryer depends on the properties of CFCs and hydrochlorofluorocarbons (HCFCs) to enable (1) heat recovery (2) sensible heating and cooling and (3) dehumidification. CFCs and HCFCs are widely used throughout the food industry as described in Table 47.6. The principal CFC refrigerants in current use are R502 and R12, while the principal HCFC in use is R22. It is estimated that the total usage of these refrigerants in the food sector in Canada is about 1800 t/year (TCEA, 1995). 

Perchloroethylene is used as a basic raw material in the manufacture of hydrofluorocarbon (HFC) 134a, a popular alternative to chlorofluorocarbon (CFC) refrigerants. It also is used in the synthesis of hydrochlorofluorocarbon (HCFC) 123 and 124 and HFC 125. 

EXAMPLE 3.14 Mass Percent Composition Calculate the mass percent of Cl in Freon-112 (C2CI4F2), a CFC refrigerant. ... 

The drop-in replacement selected for the most widely used CFC refrigerant, CCljFj, was 1,1,1,2-tetrafluoroethane, CHjFCFj (Figure 7.2). One of the routes to this compound used the existing technology for the fluorinated chromia-catalyzed route to CCljFCFj followed by a hydrodechlorination step the other used a new zinc-doped chromia catalyst precursor in a two-step process to convert CHQ=CCl2 to CH2FCF3 directly [16]. The doped chromia developed is described later in this chapter. 

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