CFCs, HFCs, HCFCs

Features Higher purity version of HFE-7100 tightly controlled for ions, metals, NV residue replaces CFCs, HFCs, HCFCs, chlorinated soivs. non-ozone depleting non-VOC SNAP complianL low surf, tens. nonflamm. resist, to hydrolysis, thermal breakdown... 

In the future, CFCs and HCFCs will play a smaller role as they are phased out and replaced by HFCs such as R-134a, R-125, and R-507 where ammonia or hydrocarbons may not be considered appropriate. Because many industrial appHcations can safely manage the safety issues with ammonia, it is expected that the use of ammonia in this sector will continue to grow and may displace up to one-third of the industrial CFC and HCFC market of the late 1990s. 

HCFCs and HFCs, because of the hydrogen in the molecule, react with hydroxyl groups in the lower atmosphere. The HCFCs are being pushed as possible temporary replacements in some applications of CFCs, though HCFCs will be phased out early in the 21st century. 

In short, a number of the rate constants for the reactions of OH with HFCs, HCFCs, and other potential CFC replacements such as partially fluorinated... 

Edison [24] disclosed the conversion of CFCs to HCFCs, HFCs, and FCs using a divided cell with a Hg pool cathode in ethanol (60 vol.%)-water containing potassium acetate. In one example, the conversion of 1,1,2-trichloro-l,2,2-trifluoroethane (CFC 113) to chlorotrifluoroethene (CTFE), an industrial monomer, at 20 mA after passing a total charge of 18,700 C was 64 mol%. The cathodic reaction is ... 

The product mixture may or may not contain HFC-1123 depending upon the nature of the catalyst.The initial conversion of CFC-113 and initial selectivities towards CFC-123, HCFC-133, HFC-143, CFC-1113 and HFC-1123 over different Pd catalysts are shown in Fig-1. It can be seen from the bar graph that the conversion of CFC-113 is in the order. PC-2>PCCAFB-2>PCCA-2>PCFLA-2>PA-2. The highest activity on carbon supported Pd catalyst is mainly due to The formation of hydrogenated products like CFC-123, HCFC-133 and HFC-143. The dehydrochlorination products on PC-2 are minimum. On the other hand. 

FIGURE 6.20 Atmospheric degradation of HFCs, HCFCs, and other CFC substitutes. Timescales for different processes are given in italics. 

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