Integrated process to coproduce trans-1-chloro-3,3,3-trifluoropropene, trans-1,3,3,3-tetrafluoropropene, and 1,1,1,3,3-pentafluoropropane
Disclosed is an integrated manufacturing process to co-produce (E) 1-chloro-3,3,3-trifluoropropene, (E) 1,3,3,3-tetrafluoropropene, and 1,1,1,3,3-pentafluoro-propane starting from a single starting feed material or a mixture of unsaturated hydrochlorocarbon feed materials comprising 1,1,1,3-tetrachloropropene and/or 1,1,3,3-tetrachloropropene. The process includes a combined liquid or vapor phase reaction/purification operation which directly produces (E) 1-chloro-3,3,3-trifluoro-propene (1233zd (E)) from these feed materials, which may also include 240fa. In the second liquid phase fluorination reactor 1233zd (E) is contacted with HF in the presence of catalyst to produce 1,1,1,3,3-pentafluoropropane (245fa) with high conversion and selectivity. A third reactor is used for dehydrofluorination of 245fa to produce (E) 1,3,3,3-tetrafluoropropene (1234ze (E)) by contacting in the liquid phase with a caustic solution or in the vapor phase using a dehydrofluorination catalyst. This operation may be followed by one or more purification processes to recover the 1234ze (E) product.
1. A process for making trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd (E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa), and trans-1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) in three continuously operated steps comprising:
(a) conducting a fluorination reaction of 1,1,3,3-tetrachloropropene and 1,3,3,3-tetrachloropropene in a fluorination reactor with excess anhydrous HF to produce a first product HCFO-1233zd (E) with high selectivity;
(b) fluorinating the produced HCFO-1233zd (E) with HF in a liquid phase in the presence of a fluorination catalyst to produce a second product HFC-245fa;
(c) dehydrofluorinating the produced HFC-245fa in a vapor phase using fluorinated Cr 2 O 3 catalyst to produce a third product comprising HFO-1234ze (E); and
(d) scrubbing the third product comprising HFO-1234ze (E);
and wherein during the continuously operated process in Step (d) products are generated as follows:
(1) during time on stream of from 180 to 200 hours, about 64.1 mole percent of trans-1234ze, about 22.7 mole percent of 245fa, and about 13.1 mole percent of cis-1234ze;
(2) during time on stream of from 630 to 650 hours, about 60.0 mole percent of trans-1234ze, about 27.4 mole percent of 245fa, and about 12.4 mole percent of cis-1234ze; and
(3) during time on stream of from 1240 to 1280 hours, about 56.6 mole percent of trans-1234ze, about 31.8 mole percent of 245fa, and 11.5 mole percent of cis-1234ze.
2. The process of claim 1 , wherein the cis-isomer, 1234ze (Z), formed in in Step (d), is converted to the desired trans-isomer 1234ze (E) by an isomerization reaction.
3. The process of claim 1 , wherein the Step (a) fluorination reaction is conducted in a liquid phase and wherein the fluorination reactor further includes an integrated distillation column for removal of the 1233zd (E) product.
4. The process of claim 1 , wherein Step (a) further comprises a purification step of the produced 1233zd (E) by distillation.
5. The process of claim 1 , wherein step (b) is conducted in a second reactor using antimony pentachloride as the fluorination catalyst, which has been partially or totally fluorinated, and wherein the second reactor further includes using a distillation column for isolation of the 245fa product.
6. The process of claim 1 , wherein the third product 1234ze (E) of Step (d) is further purified by distillation.