1,1,1,2,2-pentafluoroethane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: From the above results, it is believed that the reaction of HCFC-133a into HFC-134a occurs predominantly and HFC-143a and HFC-125 are produced from a side reaction in the first reactor, whereas the reaction of TCE into HCFC-133a is predominant but production of HFC-134a from HFC-134a is little in the second reactor.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: From the above results, it is believed that the reaction of HCFC-133a into HFC-134a occurs predominantly and HFC-143a and HFC-125 are produced from a side reaction in the first reactor, whereas the reaction of TCE into HCFC-133a is predominant but production of HFC-134a from HFC-134a is little in the second reactor.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Hydrodechlorination of the chlorine-containing saturated impurities CHClF2, CCl2F2, CHClFCF3, CHF2CClF2, CCl2FCF3, CClF2CClF2, and CClF2CF3 having boiling points of -40.8° C., -29.8° C., -12° C., -10.2° C., 3.0° C., 3.6° C., and -38.7° C., respectively, gives CH2F2, CHClF2, CH2FCF3, CHF2CHF2, CHClFCF3, CHF2CClF2, and CHF2CF3 having boiling points of -51.7° C., -40.8° C., -26.5° C., -19.7° C., -12° C., -10.2° C., and -48.5° C., respectively. Further hydrodefluorination of CH2F2 and CH2FCF3 would give CH3F (HFC-41) and CH3CF3 (HFC-143a) boiling at -78.5° C. and -47.6° C., respectively. points of -40.8° C., -29.8° C., -12° C., -10.2° C., 3.0° C., 3.6° C., and -38.7° C.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The presence of hydrogen chloride (HCl) in a HFC-125/CFC-115 containing stream further increases the difficulty of separating CFC-115 from HFC-125 compared to instances when HCl is not present. When a CFC-115/HFC-125 mixture also contains HCl, HFC-32 can be employed as an extractant in an extractive distillation that permits efficiently separating HFC-125 from CFC-115 and HCl. Extractive distillation can be employed when the components of a mixture may have differing volatilities; but, such a difference is insufficient to permit effectively separating the components by using conventional distillation. An HFC-32 extractive agent is added that causes the difference in volatilities of the components in the starting mixture to be become amplified such that the relative volatilities become sufficient to permit separation of the components in a distillation column. As previously disclosed in U.S. Pat. No. 5,421,964, which is hereby incorporated by reference, HCl can form a vapor-liquid equilibrium pinch point with HFC-125 and an azeotrope with CFC-115 that makes the separation of HFC-125 or CFC-115 from HCl by conventional distillation both inefficient and expensive. Such interactions further hinder removing CFC-115 from HFC-125 while in the presence of HCl. In accordance with the instant invention, HFC-32 can be employed as an extractant when distilling an HCl/HFC-125/CFC-115 mixture. HCl and CFC-115 are more volatile than HFC-125 when in the presence of HFC-32. Consequently, the HFC-125 can be removed in the bottoms of an extractive distillation column along with HFC-32. This aspect of the invention is shown by FIG. 3. Referring now to FIG. 3, an HFC-32 extraction agent is introduced at an upper feed point 1 of an extractive distillation column; whereas the first mixture requiring separation comprising HCl, CFC-115 and HFC-125, is introduced at a relatively lower point 2 in the column. The HFC-32 extraction agent passes downwardly through trays which are located at the center of the column and contacts a first mixture thereby forming a second mixture. While in the presence of the HFC-32, the HCl and CFC-115 become more volatile than the HFC-125, thereby allowing the HFC-125 to exit the column bottoms relatively free of HCl and CFC-115. The CFC-115 and HCl, which are exiting the top of the column 3 as column off-gas, can be condensed by using conventional reflux condensers 4. At least a portion of this condensed stream can be returned to the column as reflux, and the remainder removed as distillate 6. The HFC-125 and HFC-32 comprise a third mixture that exits from the bottom of the column 7, and can in turn can be recovered as product, or sent to yet another distillation column for separation. The specific conditions which can be used for practicing the invention depend upon a number of parameters such as the diameter of the column, feed points, number of separation stages in the column, among others. The operating pressure of the extractive distillation system may range from about 15 to 350 psia, normally about 50 to 300 psia. Typically, an increase in the HFC-32 feed rate relative to the CFC-115/HFC-125/HCl feed rate causes an increase in the purity of the separated HCl and CFC-115 relative to the HFC-125. Normally, increasing the reflux results in an decreased HFC-32 and HFC-125 in the overhead distillate. The temperature of the condenser, which is located adjacent to the top of the column, is normally sufficient to substantially condense the HCl and CFC-115. the separation of HFC-125 or CFC-115 from HCl by conventional distillation both inefficient and expensive Such interactions further hinder removing CFC-115 from HFC-125 while in the presence of HCl distilling an HCl/HFC-125/CFC-115 mixture Consequently, the HFC-125 can be removed in the bottoms of an extractive distillation column along with HFC-32 an HFC-32 extraction agent is introduced at an upper feed point 1 of an extractive distillation column separation is introduced at a relatively lower point 2 in the column The HFC-32 extraction agent thereby forming a second mixture condensed by using conventional reflux condensers 4 as reflux the remainder removed as distillate 6 The HFC-125 and HFC-32 comprise a third mixture that exits from the bottom of the column 7, and can in turn can be recovered as product another distillation column for separation depend upon a number of parameters such as the diameter of the column, feed points, number of separation stages in the column, among others Typically, an increase in the HFC-32 feed rate relative to the CFC-115/HFC-125/HCl feed rate an increase in the purity of the separated HCl and CFC-115 relative to the HFC-125 Normally, increasing the reflux

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A particularly desirable process permitted by the instant invention relates to HFC-32 that is synthecised with, or subsequently added to an HFC-125 stream which contains HF and CFC-115. The presence of HFC-32 permits the HFC-125 to be separated from the HF in a first column via removal of an HFC-32/HFC-125 azeotrope as distillate, wherein the HF may then be recycled from the bottoms to a fluorination reactor. The presence of HFC-32 also allows for separating CFC-115 from the HFC-125 in a second column by forming the CFC-115/HFC-32 azeotrope and distilling the CFC-115/HFC-32 azeotrope overhead, recovering the HFC-125 from the bottoms as product substantially-free of HF and CFC-115. By "substantially-free" is meant that the HFC-125 product contains less than about 500 ppm of HF and CFC-115, more typically less than about 50 ppm HF and CFC-115. to be separated from the HF in a first column via removal of an HFC-32/HFC-125 for separating CFC-115 from the HFC-125 in a second column

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: HFC-125 that is substantially free of CFC-115 can be produced in a process comprising contacting an HFC-125 precursor and an HFC-32 precursor with HF optionally over a catalyst to produce a mixture comprising HFC-125 and HFC-32, removing impurities other than CFC-115 from the mixture by distillation or other processes, separating the CFC-115 from the mixture comprising HFC-125 and HFC-32 by azeotropically distilling the low-boiling azeotrope of CFC-115 and HFC-32 overhead in a distillation column, and, recovering a mixture of HFC-125 with HFC-32 substantially free of CFC-115 from the bottom of the distillation column. can be produced in a process comprising

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: From the above results, it is believed that the reaction of HCFC-133a into HFC-134a occurs predominantly and HFC-143a and HFC-125 are produced from a side reaction in the first reactor, whereas the reaction of TCE into HCFC-133a is predominant but production of HFC-134a from HFC-134a is little in the second reactor.