Process for the manufacture of 2,3,3,3-tetrafluoropropene by gas phase fluorination of pentachloropropane
View Patent ↗The present invention provides a process of catalytic fluorination in gas phase of product 1,1,1,2,3-pentachloropropane or/and 1,1,2,2,3-pentachloropropane into product 2,3,3,3-tetrafluoropropene in presence of a catalyst.
1. A process for producing 2,3,3,3-tetrafluoropropene (1234yf) comprising:
introducing 1,1,1,2,3-pentachloropropane (240db) and/or 1,1,2,2,3-pentachloropropane (240aa), HF, 1,1,1,2,2-pentafluoropropane (245cb) and 2-chloro-3,3,3-trifluoropropene (1233xf) into a gas phase fluorination reactor containing a fluorination catalyst, wherein the 245cb introduced to the reactor is provided from a recycle loop, and
producing 1234yf and 1233xf in the reactor, wherein 1234yf and the recycled 245cb form an equilibrium in the reactor thus resulting in increased production of 1234yf and a constant rate of 245cb in the recycle loop.
2. The process of claim 1 , wherein the process is carried out in a single stage.
3. The process of claim 1 , wherein the product 2,3,3,3-tetrafluoropropene is present at a concentration of at least 1%.
4. The process of claim 1 , wherein said catalyst is a chromium catalyst.
5. The process of claim 4 , wherein said catalyst further comprises a co-catalyst selected from the group consisting of Ni, Co, Zn, Mn, Mg and mixtures thereof, and wherein said co-catalyst is present in an amount from about 1-10 wt % of said fluorination catalyst.
6. The process of claim 1 , wherein the process is carried out in the presence of a catalyst comprising Ni—Cr.
7. The process of claim 1 , wherein said catalyst is supported on a support comprising fluorinated alumina, fluorinated chromia, fluorinated activated carbon or graphite carbon.
8. The process of claim 1 , wherein the fluorination catalyst is activated with a fluorine-containing compound.
9. The process of claim 1 , wherein the 1,1,1,2,3-pentachloropropane contains up to 40 mol % of isomer 1,1,2,2,3-pentachloropropane.
10. The process of claim 1 , wherein the process is carried out at a pressure from 3 to 20 bars.
11. The process of claim 1 , wherein the process is carried out at a temperature of from 200 to 450° C.
12. The process of claim 11 , wherein the process is carried out at a temperature of 350 to 450° C.