Method for avoiding the generation of by-products during the production of haloalkane compounds
View Patent ↗Disclosed is a process for the manufacture of haloalkane compounds, and more particularly, to an improved process for the manufacture of the compound 1,1,1,3,3-pentachloropropane (HCC-240fa), which mitigates the formation of by-products. The present invention is also useful in the manufacture of other haloalkane compounds such as HCC-250 and HCC-360. One embodiment of the process comprises a method and system for avoiding the formation of polyvinyl chloride during the production of HCC-240fa from CCl 4 , in which vinyl chloride (VCM) is fed into a reactor as a vapor instead of as a liquid, using a diffusing device to further increase the contact surface between VCM vapor and CCl 4 .
1. A process for the manufacture of haloalkane compounds comprising reacting carbon tetrachloride and an alkene wherein poly(alkene) by-products are minimized during the reaction by the use of a diffusing device with an iron catalyst and one or more organo-phosphate compounds as a co-catalyst;
wherein the alkene is selected from the group consisting of vinyl chloride, ethylene and 2-chloropropene; and
wherein the haloalkane compounds are selected from the group consisting of HCC-240fa, HCC-250 and HCC-360; and wherein the diffusing device increases the contact surface between the reactants.
2. The process of claim 1 , wherein the iron catalyst has a form selected from the group consisting of iron powder, iron balls, iron wire, iron shavings, and mixtures thereof.
3. The process of claim 2 , wherein the iron powder comprises a fine powder of pure metallic iron.
4. The process of claim 3 , wherein the iron powder has a particle size smaller than 325 mesh.
5. The process of claim 3 , wherein the iron powder is added to the reactor by powder slurry in carbon tetrachloride.
6. The process of claim 3 , wherein the iron powder is added to the reactor by powder slurry in the organophosphate.
7. The process of claim 3 , wherein the iron powder is added to the reactor by powder slurry in a mixture of CCl 4 and the organophosphate.
8. The process of claim 1 , wherein the organophosphate co-catalyst is selected from the group consisting of triphenylphosphate, tributylphosphate, trimethyl-phosphate, triethylphosphate, tripropylphosphate, and mixtures of two or more of these.
9. The process of claim 1 , which is conducted as a continuous operation.
10. The process of claim 1 , which is conducted as a batch operation.
11. The process of claim 1 , wherein the diffusing device comprises a dip tube.
12. The process of claim 1 , wherein the diffusing device comprises a sponge type gas diffuser.
13. An improved process for manufacturing HCC-240fa, which comprises:
(a) providing a continuous CCl 4 liquid stream and a continuous VCM vapor stream;
(b) producing a product stream in a reactor by reacting carbon tetrachloride and vinyl chloride in the presence of a catalyst mixture consisting of iron metal and tributylphosphate under conditions sufficient to produce HCC-240fa and not produce significant amounts of PVC by the use of a diffusing device, wherein the diffusing device increases the contact surface between the reactants; and
(c) recovering HCC-240fa from said product stream of step (b).
14. The process of claim 13 , wherein the VCM vapor is fed into a reactor precharged with CCl 4 , tributylphosphate and iron powder through a dip tube.
15. The process of claim 13 , wherein the VCM vapor is fed into a reactor precharged with CCl 4 , tributylphosphate and iron powder through a sponge type gas diffuser.
16. The process of claim 13 , wherein the iron powder has a particle size smaller than 325 mesh.
17. The process of claim 13 , wherein the iron powder is added to the reactor by powder slurry in carbon tetrachloride.
18. The process of claim 13 , wherein the iron powder is added to the reactor by powder slurry in the tributylphosphate.
19. The process of claim 13 , wherein the iron powder is added to the reactor by powder slurry in a mixture of CCl 4 and the tributylphosphate.