Azeotrope-like compositions of 1,1,1,3,3-pentachloropropane and carbon tetrachloride
View Patent ↗The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentachloropropane (HCC-240fa) and carbon tetrachloride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-245fa. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol propellant.
1. An azeotropic or azeotrope-like composition, which consists essentially of 1,1,1,3,3-pentachloropropane and carbon tetrachloride.
2. The composition of claim 1 having a boiling point of from about 77.7° C. to about 77.9° C. at about 14.4 psia.
3. The composition of claim 2 consisting essentially of from about 0.01 to about 10 weight percent 1,1,1,3,3-pentachloropropane and from about 99.9 to about 90 weight percent carbon tetrachloride.
4. The composition of claim 2 consisting essentially of from about 0.02 to about 5 weight percent 1,1,1,3,3-pentachloropropane and from about 99.8 to about 95 weight percent carbon tetrachloride.
5. The composition of claim 2 , which consists essentially of from about 0.05 weight percent to about 3 weight percent 1,1,1,3,3-pentachloropropane and from about 97 to about 99.5 weight percent carbon tetrachloride.
6. A process for separating 1,1,1,3,3-pentachloropropane from an azeotropic or azeotrope-like composition of 1,1,1,3,3-pentachloropropane and carbon tetrachloride comprising the steps of (A) distilling a composition comprising an azeotropic or azeotrope-like composition of 1,1,1,3,3-pentachloropropane and carbon tetrachloride at a first pressure to produce a first overhead stream enriched in either the 1,1,1,3,3-pentachloropropane or the carbon tetrachloride and a first bottoms stream enriched in the other component; and (B) redistilling the first overhead stream at a second pressure to produce a second overhead stream enriched in the component enriched in the first bottoms stream and a second bottoms stream enriched in the component enriched in the first overhead stream.
7. The process of claim 6 wherein said distillation steps are performed as a continuous process.
8. The process of claim 7 wherein said distillation step (A) is performed using a different distillation column than redistillation step (B).
9. A process for removing 1,1,1,3,3-pentachloropropane from a mixture containing 1,1,1,3,3-pentachloropropane and at least one impurity, the process comprising adding carbon tetrachloride to a mixture containing 1,1,1,3,3-pentachloropropane and at least one impurity in an amount sufficient to form an azeotropic or azeotrope-like composition of the 1,1,1,3,3-pentachloropropane and the carbon tetrachloride, and thereafter separating the azeotropic or azeotrope-like composition from the impurity.
10. The process of claim 9 wherein the impurity does not form an azeotropic or azeotrope-like composition with 1,1,1,3,3-pentachloropropane, carbon tetrachloride or a mixture of 1,1,1,3,3-pentachloropropane and carbon tetrachloride.
11. The process of claim 10 wherein the impurity comprises a halocarbon.
12. The process of claim 10 wherein the impurity is miscible with 1,1,1,3,3-pentachloropropane.
13. The process of claim 10 wherein said separating step comprises distillation.
14. The process of claim 10 further comprising the step of separating 1,1,1,3,3-pentachloropropane from an azeotropic or azeotrope-like composition of 1,1,1,3,3-pentachloropropane and carbon tetrachloride using pressure swing distillation.
15. The process of claim 10 wherein the azeotropic or azeotrope-like composition comprises from about 0.01 to about 10 weight percent 1,1,1,3,3-pentachloropropane and from about 90 to about 99.9 weight percent carbon tetrachloride.
16. The. process of claim 15 wherein the azeotropic or azeotrope-like composition consists essentially of from about 0.01 weight percent to about 10 weight percent 1,1,1,3,3-pentachloropropane and from about 90 to about 99.9 weight percent carbon tetrachloride.
17. A method of forming an azeotropic or azeotrope-like composition which comprises combining 1,1,1,3,3-pentachloropropane and carbon tetrachloride in amounts effective and under conditions sufficient to form an azeotropic or azeotrope-like composition consisting essentially of 1,1,1,3,3-pentachloropropane and carbon tetrachloride.
18. A method of forming an azeotropic or azeotrope-like composition, which comprises combining from about 0.01 to about 10 weight percent 1,1,1,3,3-pentachloropropane and from about 90 to about 99.99 weight percent carbon tetrachloride, which composition has a vapor pressure of about 14.4 psia to about 14.7 psia at about a temperature of about 78° C.
19. A method which comprises distilling a mixture comprising 1,1,1,3,3-pentachloropropane and carbon tetrachloride to produce a stream comprising an azeotropic or azeotrope-like composition of 1,1,1,3,3-pentachloropropane and carbon tetrachloride.