Method for purifying trans-1,3,3,3-tetrafluoropropene
Disclosed is a method for purifying a trans-1,3,3,3-tetrafluoropropene, in which a composition containing trans-1,3,3,3-tetrafluoropropene and at least one impurity selected from the group consisting of C 2 H 3 ClF 2 , CF 3 CH 2 CHClF, CF 3 CH 2 CHF 2 , CHF 2 CH═CF 2 , CF 3 CH═CHCl, CF 3 CH═CH 2 , CF 3 C≡CH, and cis-1,3,3,3-tetrafluoropropene is brought into contact with a solid adsorbent to reduce an impurity content thereof. By this method, it is possible to remove the impurity in trans-1,3,3,3-tetrafluoropropene by a simple operation.
1. A method for purifying a trans-1,3,3,3-tetrafluoropropene, comprising the steps of:
(a) dechlorinating a molecular sieve 13X to prepare a dechlorinated molecular sieve 13X; and
(b) bringing a composition containing trans-1,3,3,3-tetrafluoropropene and at least one impurity selected from the group consisting of C 2 H 3 ClF 2 , CF 3 CH 2 CHClF, CF 3 CH 2 CHF 2 , CHF 2 CH═CF 2 , CF 3 CH═CHCl, CF 3 CH═CH 2 , CF 3 C≡CH, and cis-1,3,3,3-tetrafluoropropene into contact with the dechlorinated molecular sieve 13X as a solid adsorbent to reduce an impurity content thereof.
2. The purification method according to claim 1 , wherein at least one impurity is selected from the group consisting of cis-1,3,3,3-tetrafluoropropene and CF 3 CH 2 CHF 2 .
3. A solid-liquid, heterogeneous mixture, comprising:
(a) a composition containing trans-1,3,3,3-tetrafluoropropene and at least one organic matter selected from the group consisting of C 2 H 3 ClF 2 , CF 3 CH 2 CHClF, CF 3 CH 2 CHF 2 , CHF 2 CH═CF 2 , CF 3 CH═CHCl, CF 3 CH═CH 2 , CF 3 C≡CH, and cis-1,3,3,3-tetrafluoropropene, and
(b) a dechlorinated molecular sieve 13X as a solid adsorbent.
4. The purification method according to claim 1 , wherein the dechlorination is conducted by immersing the molecular sieve 13X in an ion-exchanged water containing no chlorine ions or pure water.
5. The purification method according to claim 1 , wherein the dechlorination is conducted by immersing the molecular sieve 13X in an alkali metal fluoride aqueous solution and then washing the molecular sieve 13X with an ion-exchanged water.
6. The purification method according to claim 5 , wherein the alkali metal fluoride aqueous solution has a concentration of from 0.1 mass % to 5 mass % of an alkali metal fluoride.
7. The purification method according to claim 6 , wherein the alkali metal fluoride is selected from the group consisting of KF, NaF, and CsF.
8. The purification method according to claim 7 , wherein the alkali metal fluoride is NaF.
9. The purification method according to claim 1 , further comprising the step of drying the dechlorinated molecular sieve 13X by heating.