# US 8,772,554 B2 · Process for preparing 2,3,3,3-tetrafluoropropene

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- Number: US 8,772,554 B2
- Document ID: US8772554B2
- Status: Granted
- Kind: B2
- Application number: 14/127,258
- Filed: 2012-06-22
- Published: 2014-05-01
- Granted: 2014-07-08
- Earliest claimed: 2011-07-26
- Assignees: Daikin Industries, Ltd.
- Applicants: Masatoshi Nose; Yuzo Komatsu
- Inventors: Masatoshi Nose; Yuzo Komatsu
- Web page: https://patentgrep.com/patent/US8772554B2

## CPC

- C07C 17/20: of halogen atoms by other halogen atoms
- C07C 17/206: {the other compound being HX}
- C07C 17/25: by splitting-off hydrogen halides from halogenated hydrocarbons
- C07C 21/18: containing fluorine
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The present invention provides a method for efficiently preparing 2,3,3,3-tetrafluoropropene (HFO-1234yf) by a simple and economically advantageous method that is suitable for implementation on an industrial scale. The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene, comprising the step of: (1) in a reactor, (1-1) reacting 1,1,1,2,3-penta-chloropropane with hydrogen fluoride in an amount of 10 to 100 mol per mole of the 1,1,1,2,3-pentachloropropane 1; (1-2) in the presence of chromic oxide represented by composition formula: CrOm (1.5<m<3) or fluorinated chromic oxide obtained by fluorinating the chromic oxide; (1-3) in the presence of oxygen in an amount of 0.02 to 1 mol per mole of the 1,1,1,2,3-pentachloropropane; and (1-4) in the gas phase within a temperature range of 320 to 390 degrees centigrade, thereby obtaining a reaction product containing 2,3,3,3-tetrafluoropropene.

## Claims

### Claim 1

A process for preparing 2,3,3,3-tetrafluoropropene, comprising the step of:
(1) in a reactor,
(1-1) reacting 1,1,1,2,3-pentachloropropane with hydrogen fluoride in an amount of 10 to 100 mol per mole of the 1,1,1,2,3-pentachloropropane;
(1-2) in the presence of chromic oxide represented by composition formula: CrOm (1.5<m<3) or fluorinated chromic oxide obtained by fluorinating the chromic oxide;
(1-3) in the presence of oxygen in an amount of 0.02 to 1 mol per mole of the 1,1,1,2,3-pentachloropropane; and
(1-4) in the gas phase within a temperature range of 320 to 390° C., thereby obtaining a reaction product containing 2,3,3,3-tetrafluoropropene.

### Claim 2 (depends on 1)

The preparation process according to claim 1, wherein
the reaction product obtained in step (1) contains hydrogen chloride, 2,3,3,3-tetrafluoropropene, at least one compound selected from 2-chloro-3,3,3-trifluoropropene and 1,1,1,2,2-pentafluoropropane, and hydrogen fluoride; and
the preparation process further comprises the step of:
(2) recycling at least one compound selected from 2-chloro-3,3,3-trifluoropropene and 1,1,1,2,2-pentafluoropropane in the reaction product and hydrogen fluoride in the reactor.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the amount of the hydrogen fluoride is 15 to 50 mol per mole of the 1,1,1,2,3-pentachloropropane.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the reaction pressure of the reactor is 0.08 to 0.8 MPa.

### Claim 5 (depends on 2)

The process according to claim 2, wherein step (1) and step (2) are continuously performed.

### Claim 6 (depends on 2)

The process according to claim 2, wherein the amount of the hydrogen fluoride is 15 to 50 mol per mole of the 1,1,1,2,3-pentachloropropane.

### Claim 7 (depends on 2)

The process according to claim 2, wherein the reaction pressure of the reactor is 0.08 to 0.8 MPa.

### Claim 8 (depends on 3)

The process according to claim 3, wherein the reaction pressure of the reactor is 0.08 to 0.8 MPa.

### Claim 9 (depends on 6)

The process according to claim 6, wherein the reaction pressure of the reactor is 0.08 to 0.8 MPa.

### Claim 10 (depends on 3)

The process according to claim 3, wherein step (1) and step (2) are continuously performed.

### Claim 11 (depends on 4)

The process according to claim 4, wherein step (1) and step (2) are continuously performed.

### Claim 12 (depends on 6)

The process according to claim 6, wherein step (1) and step (2) are continuously performed.

### Claim 13 (depends on 7)

The process according to claim 7, wherein step (1) and step (2) are continuously performed.

### Claim 14 (depends on 8)

The process according to claim 8, wherein step (1) and step (2) are continuously performed.

### Claim 15 (depends on 9)

The process according to claim 9, wherein step (1) and step (2) are continuously performed.