Manufacture of 1,1,1,2,3,3-hexafluoropropane and 1,1,1,2-tetrafluoropropane via catalytic hydrogenation
View Patent ↗A process for producing hydrofluorocarbon compounds represented by the following formula: CF 3 CHFCH m+1 F n wherein m is 0 or 2; n is 0 or 2; and m+n=2. The process has the step of contacting, i.e., reacting, hydrogen with a precursor compound represented by the following formula: CF 3 CF═CH m F n wherein m is 0 or 2; n is 0 or 2; and m+n=2. The contact is carried out in the presence of a solid catalyst and in the presence or absence of an inert gas. The catalyst is selected from the group consisting of: Fe, Co, Ni, Cu, Cr, Ru, Rh, Ag, Re, Os, Ir, Pt, Au, Sn, and any combinations thereof. For the hydrogenation of 1234yf to 254eb, Pd can also be used as catalyst in addition to the other above-referenced metals. These metals are preferably supported on a carrier such as activated carbon.
1. A process for producing hydrofluorocarbons represented by the following formula I:
CF 3 CHFCH m+1 F n
wherein m is 0 or 2; n is 0 or 2; and m+n=2, comprising: contacting hydrogen with a compound represented by the following formula II:
CF 3 CF═CH m F n
wherein m is 0 or 2; n is 0 or 2; and m+n=2 in the presence of a metal catalyst selected from the group consisting of Fe, Co, Ni, Cu, Cr, Ru, Rh, Ag, Re, Os, Ir, Pt, Au, Sn, and any combination thereof, and wherein m and n of the compound of formula II and hydrofluorocarbon of formula I have a same value.
2. The process of claim 1 , wherein m=0 and n=2, and wherein the hydrofluorocarbon is 1,1,1,2,3,3-hexafluoropropane.
3. The process of claim 1 , wherein m=2 and n=0, and wherein the hydrofluorocarbon is 1,1,1,2-tetrafluoropropane.
4. The process of claim 1 , wherein the catalyst is a supported catalyst.
5. The process of claim 4 , wherein the support is selected from the group consisting of: C, Al 2 O 3 , SiO 2 , MgO, ZrO 2 , TiO 2 , ZnO, CeO 2 , La 2 O 3 , a metal fluoride, and BaSO 4 .
6. The process of claim 5 , wherein the catalyst is nickel supported on an activated carbon.
7. The process of claim 4 , wherein the metal loading on the support is about 0.01 wt % to about 50 wt %.
8. The process of claim 7 , wherein the metal loading on the support is about 0.1 wt % to about 25 wt %.
9. The process of claim 8 , wherein the metal loading on the support is about 1 wt % to about 10 wt %.
10. The process of claim 1 , wherein the catalyst is calcined at about 200° C. to about 500° C. prior to being contacted with hydrogen.
11. The process of claim 1 , wherein the catalyst is calcined at about 200° C. to about 600° C. prior to being contacted with hydrogen.
12. The process of claim 1 , wherein the catalyst is calcined at about 350° C. to about 500° C. prior to being contacted with hydrogen.
13. The process of claim 1 , wherein reaction temperature is about −30° C. to about 500° C.
14. The process of claim 1 , wherein reaction pressure is about 0.01 atm to about 100 atm.
15. The process of claim 1 , wherein the contact time is from about 0.0001 second to about 100 hours.
16. The process of claim 1 , wherein hydrogen to CF 3 CF═CH m F n molar ratio ranges from about 0.5 to about 20.
17. The process of claim 1 , wherein the process is carried out in a reactor selected from the group consisting of: a continuous fixed-bed reactor, a trickle-bed reactor, a moving-bed reactor, a batch reactor, and a CSTR.
18. The process of claim 1 , wherein the contacting is carried out in a batch manner.
19. The process of claim 1 , wherein the contacting is carried out in a continuous manner.
20. The process of claim 1 , wherein the contacting is carried out when the CF 3 CF═CH m F n compound is in vapor phase.
21. The process of claim 1 , wherein the contacting is carried out when the CF 3 CF═CH m F n compound is in liquid phase.
22. The process of claim 1 , wherein the feed is diluted with an inert gas, a target product and/or a recycle stream, and any combination thereof.
23. The process of claim 1 , wherein the catalyst is diluted by bare support or metal packings.
24. The process of claim 1 , wherein at least a portion of the hydrofluorocarbon and any unreacted hydrogen is recycled.
25. The process of claim 1 , wherein the catalyst is an unsupported catalyst.
26. The process of claim 1 , wherein the catalyst is Raney Ni or Cu—Cr.
27. A process for producing 1,1,1,2-tetrafluoropropane, comprising contacting hydrogen with 1,1,1,2-tetrafluoropropene in the presence of a Pd catalyst.
28. The process in claim 27 , wherein the catalyst is palladium supported on an activated carbon.