Process for producing 1,3,3,3-tetrafluoropropene

1. A process for producing 1,3,3,3-tetrafluoropropene, comprising:

a) a first step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a liquid phase and in the absence of the fluorination catalyst, within a reaction pressure range of 0.5 to 4.2 MPa, and within a reaction temperature range of 100° C. to 160° C., thereby obtaining 1-chloro-3,3,3-trifluoropropene,

wherein 1,1,1,3,3-pentachloropropane and hydrogen fluoride are introduced into a reaction system while hydrogen chloride and 1-chloro-3,3,3-trifluoropropene generated from the reaction are extracted from the reaction system; and

b) a second step of reacting 1-chloro-3,3,3-trifluoropropene obtained by the first step with hydrogen fluoride in a gaseous phase and in the presence of a fluorination catalyst.

2. A process as claimed in claim 1 , further comprising:

a step of removing an excessive amount of hydrogen fluoride (HF), 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane from a reaction mixture containing 1,3,3,3-tetrafluoropropene obtained by the second step (a step A);

a step of further removing a remaining hydrogen fluoride (HF) after the step A (a step B); and

a step of removing hydrogen chloride (HCl) from 1,3,3,3-tetrafluoropropene obtained by the step B (a step C).

3. A process as claimed in claim 1 , wherein the fluorination catalyst used when reacting 1-chloro-3,3,3-trifluoropropene with a fluorination agent in the gaseous phase and in the presence of the fluorination catalyst (the second step) is one of: activated carbon; activated carbon that carries one of oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride and oxyfluorinated chloride of at least one kind of metals selected from chromium, titanium, aluminum, manganese, nickel, cobalt and zirconium, thereon; alumina; fluorinated alumina; aluminum fluoride; zirconia; and fluorinated zirconia.

4. A process for producing trans-1,3,3,3-tetrafluoropropene, comprising the step of:

purifying 1,3,3,3-tetrafluoropropene obtained by the process of claim 1 .

5. A process as claimed in claim 4 , wherein 1-chloro-3,3,3-trifluoropropene, cis-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane contained in 1,3,3,3-tetrafluoropropene, which are separated from trans-1,3,3,3-tetrafluoropropene obtained by claim 4 , are used as the raw material of the second step again.

6. A process as claimed in claim 1 , further comprising the step of:

bringing 1,3,3,3-tetrafluoropropene obtained by the process of claim 1 into contact with a zeolite thereby dehydrating the 1,3,3,3-tetrafluoropropene.

7. A process as claimed in claim 6 , wherein the zeolite is a zeolite belonging to Faujasite genus.

8. A process as claimed in claim 6 , wherein the zeolite is a synthetic zeolite of one type of 3A, 4A, 5A, 10X and 13X.

9. A process as claimed in claim 1 , further comprising:

a step of washing the product of the first step which product comprises 1-chloro-3,3,3-trifluoropropene, with water or an alkaline aqueous solution to remove an acidic substance, followed by drying and then distillation to remove organic impurities.

10. A process as claimed in claim 2 , further comprising:

a step of bringing high boiling point contents obtained after the step A back to the second step.

11. A process as claimed in claim 2 , wherein the step B further comprises one of the steps (a) to (c) to remove hydrogen fluoride (HF):

(a) a step of reacting hydrogen fluoride with potassium fluoride or sodium fluoride to forming a complex of hydrogen fluoride, followed by reacting calcium chloride, calcium hydroxide, calcium oxide, calcium carbonate or an aqueous solution of these with hydrogen fluoride to form calcium fluoride (CaF 2 );

(b) a step of reacting hydrogen fluoride with sodium chloride or potassium chloride thereby forming a metal fluoride salt corresponding respectively to these to; and

(c) a step of reacting sulfuric acid with hydrogen fluoride.

12. A process for producing 1,3,3,3-tetrafluoropropene, comprising:

a) a first step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a liquid phase and in the absence of the fluorination catalyst within a reaction pressure range of 0.5 to 4.2 MPa and within a reaction temperature range of 100 to 160° C. thereby obtaining 1-chloro•3,3,3-trifluoropropene

wherein 1,1,1,3,3-pentachloropropane and hydrogen fluoride are introduced into a reaction system while hydrogen chloride and 1-chloro-3,3,3-trifluoropropene generated from the reaction are extracted from the reaction system;

b) a step of washing the product of the first step which product comprises 1-chloro-3,3,3-trifluoropropene, with water or an alkaline aqueous solution to remove an acidic substance, followed by drying and then distillation to remove organic impurities;

c) a second step of reacting 1-chloro-3,3,3-trifluoropropene obtained by the first step with hydrogen fluoride in a gaseous phase and in the presence of a fluorination catalyst,

wherein the fluorination catalyst is one of: activated carbon; activated carbon that carries one of oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride and oxyfluorinated chloride of at least one kind of metals selected from chromium, titanium, aluminum, manganese, nickel, cobalt and zirconium, thereon; alumina; fluorinated alumina; aluminum fluoride; zirconia; and fluorinated zirconia;

d) a step of removing an excessive amount of hydrogen fluoride (HF), 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane from a reaction mixture containing 1,3,3,3-tetrafluoropropene obtained by the second step (a step A);

e) a step of further removing a remaining hydrogen fluoride (HF) after the step A (a step B); and

f) a step of removing hydrogen chloride (HCl) from 1,3,3,3-tetrafluoropropene obtained by the step B (a step C).

13. A process as claimed in claim 12 , further comprising:

a step of bringing high boiling point contents obtained after the step A back to the second step.

14. A process as claimed in claim 12 , wherein the step B further comprises one of the steps (a) to (c) to remove hydrogen fluoride (HF):

(a) a step of reacting hydrogen fluoride with potassium fluoride or sodium fluoride to forming a complex of hydrogen fluoride, followed by reacting calcium chloride, calcium hydroxide, calcium oxide, calcium carbonate or an aqueous solution of these with hydrogen fluoride to form calcium fluoride (CaF 2 );

(b) a step of reacting hydrogen fluoride with sodium chloride or potassium chloride thereby forming a metal fluoride salt corresponding respectively to these to; and

(c) a step of reacting sulfuric acid with hydrogen fluoride.