Stable 2,3,3,3-tetrafluoropropene composition

Abstract

A stable composition (CS) including at least x wt.-% 2,3,3,3-tetrafluoropropene (99.8 x<100), at most y wt.-% unsaturated compound(s) (Ia) (0<y 0.2) selected from among 3,3,3-trifluoropropene (HFO-1243zf) and the positional isomers of 2,3,3,3-tetrafluoropropene, such as 1,3,3,3-tetrafluoropropene (isomers Z and E) and 1,1,2,3-tetrafluoropropene, and, optionally, at most 500 ppm of 3,3,3-trifluoropropyne and/or at most 200 ppm 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

Claims

1. A stable composition comprising 99.8 x<100% by weight of 2,3,3,3-tetrafluoropropene, 0<y0.15% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, 3,3,3-trifluoropropene (HFO-1243zf), and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene (HFO-1225ye), wherein the composition contains at most 500 ppm of 3,3,3-trifluoropropyne and/or at most 200 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

2. The stable composition according to claim 1, further comprising at least one compound (Ib) selected from the group consisting of 1,1,1,2-tetrafluoropropane (HFC-254eb), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2-trifluoroethane (HFC-143), 1,1,1,2,3,3-hexafluoropropane, hexafluoropropene, cyclohexafluoropropene, 1,1,1,3,3-pentafluoropropene (HFO-1225zc), and mixtures thereof.

3. The stable composition according to claim 2, wherein the compound(s) (Ib) represent(s) at most 500 ppm of the stable composition.

4. The stable composition according to claim 1, wherein the stable composition comprises at least 99.85% by weight of 2,3,3,3-tetrafluoropropene, 0<y0.1% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, 3,3,3-trifluoropropene (HFO-1243zf), and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene (HFO-1225ye), wherein the composition contains at most 250 ppm of 3,3,3-trifluoropropyne and/or at most 50 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

5. The stable composition according to claim 1, wherein the stable composition comprises at least 99.9% by weight of 2,3,3,3-tetrafluoropropene, 0<y0.05% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, 3,3,3-trifluoropropene (HFO-1243zf), and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene (HFO-1225ye), wherein the composition contains at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

6. The stable composition according to claim 1, wherein the stable composition comprises from 99.85 to 99.98% by weight of 2,3,3,3-tetrafluoropropene, from 0<y0.1% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, 3,3,3-trifluoropropene (HFO-1243zf), and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene (HFO-1225ye) and/or compounds (Ib), wherein the composition contains at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye) and/or at most 400 ppm of compounds (Ib).

7. The stable composition according to claim 1, wherein the stable composition is configured for use as a heat transfer agent in stationary or motor-vehicle air conditioning, refrigeration and heat pumps.

8. The stable composition according to claim 1, wherein the stable composition further comprises a lubricant.

9. The stable composition according to claim 8, wherein the lubricant is selected from the group consisting of polyol esters (POEs), polyalkylene glycols (PAGs), polyalkylene glycol esters and polyvinyl ethers (PVEs).

10. The stable composition according to claim 1, wherein the positional isomers of 2,3,3,3-tetrafluoropropene comprise E-1,3,3,3-tetrafluoropropene, Z-1,3,3,3-tetrafluoropropene, and 1,1,2,3-tetrafluoropropene.

11. 2,3,3,3-Tetrafluoropropene which has a purity of greater than or equal to 99.8% by weight and less than 100% by weight and which comprises 3,3,3-trifluoropropene (HFO-1243zf), at most 0.15% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene and/or compounds (Ib), wherein the 2,3,3,3-tetrafluoropropene contains at most 500 ppm of 3,3,3-trifluoropropyne and/or at most 200 ppm of 1,1,1,2,3-pentafluoropropene and/or at most 500 ppm of compounds (Ib).

12. 2,3,3,3-Tetrafluoropropene according to claim 11, characterized by a purity of greater than or equal to 99.9% by weight and less than 100% by weight and comprising 3,3,3-trifluoropropene (HFO-1243zf), at most 0.05% by weight of the positional isomers of 2,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropyne and/or 1,1,1,2,3-pentafluoropropene and/or compounds (Ib), wherein the 2,3,3,3-tetrafluoropropene contains at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene and/or at most 500 ppm of compounds (Ib).

13. 2,3,3,3-Tetrafluoropropene according to claim 11, wherein the positional isomers of 2,3,3,3-tetrafluoropropene comprise E-1,3,3,3-tetrafluoropropene, and Z-1,3,3,3-tetrafluoropropene, and 1,1,2,3-tetrafluoropropene.

Description

DETAILED DESCRIPTION

(1) The Applicant Company has now developed a 2,3,3,3-tetrafluoropropene composition which makes it possible to improve the thermal stability when it is used in refrigeration systems.

(2) A subject-matter of the present invention is thus a stable composition (SC) comprising at least x % by weight of 2,3,3,3-tetrafluoropropene (99.8x<100), at most y % by weight of unsaturated compound(s) (Ia) (0<y0.2) chosen from 3,3,3-trifluoropropene (HFO-1243zf) and the positional isomers of 2,3,3,3-tetrafluoropropene, such as 1,3,3,3-tetrafluoropropene (Z and E isomers) and 1,1,2,3-tetrafluoropropene, and optionally at most 500 ppm of 3,3,3-trifluoropropyne and/or at most 200 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

(3) The stable composition according to the present invention can additionally comprise at least one of the compounds (Ib) chosen from 1,1,1,2-tetrafluoropropane (HFC-254eb), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2-trifluoroethane (HFC-143), 1,1,1,2,3,3-hexafluoropropane, hexafluoropropene, cyclohexafluoropropene and 1,1,1,3,3-pentafluoropropene (HFO-1225zc).

(4) The combined compounds (Ib) present in the composition according to the present invention represent at most 500 ppm.

(5) Preferably, the SC composition comprises at least 99.85% by weight of 2,3,3,3-tetrafluoropropene, at most y % by weight of unsaturated compound(s) (Ia) (0<y0.15) chosen from 3,3,3-trifluoropropene (HFO-1243zf) and the positional isomers of 2,3,3,3-tetrafluoropropene, such as 1,3,3,3-tetrafluoropropene (Z and E isomers) and 1,1,2,3-tetrafluoropropene, and optionally at most 250 ppm of 3,3,3-trifluoropropyne and/or at most 50 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

(6) The SC composition which is particularly preferred comprises at least 99.9% by weight of 2,3,3,3-tetrafluoropropene, at most y % by weight of unsaturated compound(s) (Ia) (0<y0.1) chosen from 3,3,3-trifluoropropene (HFO-1243zf) and the positional isomers of 2,3,3,3-tetrafluoropropene, such as 1,3,3,3-tetrafluoropropene (Z and E isomers) and 1,1,2,3-tetrafluoropropene, and optionally at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye).

(7) According to a preferred embodiment of the invention, the SC composition comprises from 99.85 to 99.98% by weight of 2,3,3,3-tetrafluoropropene, from 0.02 to 0.15% by weight of unsaturated compound(s) (Ia) chosen from 3,3,3-trifluoropropene (HFO-1243zf) and the positional isomers of 2,3,3,3-tetrafluoropropene, such as 1,3,3,3-tetrafluoropropene (Z and E isomers) and 1,1,2,3-tetrafluoropropene, and optionally at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene (HFO-1225ye) and/or at most 400 ppm of compounds (Ib).

(8) The stable composition according to the invention exhibits the advantage of being able to be obtained directly by a process for the manufacture of 2,3,3,3-tetrafluoropropene, optionally after at least one separation stage.

(9) Another subject-matter of the present invention is 2,3,3,3-tetrafluoropropene which has a purity of greater than or equal to 99.8% by weight and less than 100% by weight and which comprises at most 0.2% by weight of unsaturated compounds (Ia), optionally at most 500 ppm of 3,3,3-trifluoropropyne and/or at most 200 ppm of 1,1,1,2,3-pentafluoropropene and/or at most 500 ppm of compounds (Ib).

(10) An additional subject-matter of the present invention is 2,3,3,3-tetrafluoropropene which has a purity of greater than or equal to 99.9% by weight and less than 100% by weight and which comprises at most 0.1% by weight of unsaturated compounds (Ia), optionally at most 200 ppm of 3,3,3-trifluoropropyne and/or at most 5 ppm of 1,1,1,2,3-pentafluoropropene and/or at most 500 ppm of compounds (Ib).

(11) 2,3,3,3-Tetrafluoropropene can be obtained from hexafluoropropene (HFP) in at least 4 reaction stages:(i) hydrogenation of HFP in the presence of a hydrogenation catalyst in a solid phase to give 1,1,1,2,3,3-hexafluoropropane; (ii) dehydrofluorination of the 1,1,1,2,3,3-hexafluoropropane obtained in stage (i) in the liquid phase using an alkali metal hydroxide or in the gas phase in the presence of a dehydrohalogenation catalyst to give 1,1,1,2,3-pentafluoropropene; (iii) hydrogenation of the HFO-1225ye obtained in (ii) in the presence of a hydrogenation catalyst in the solid phase to give 1,1,1,2,3-pentafluoropropane; (iv) dehydrofluorination of the HFC-245eb obtained in stage (iii) in the liquid phase using an alkali metal hydroxide or in the gas phase in the presence of a dehydrohalogenation catalyst to give 2,3,3,3-tetrafluoropropene.

(12) 2,3,3,3-Tetrafluoropropene can be obtained from hexafluoropropene (HFP) in at least 2 reaction stages:(i) hydrogenation of HFP in the presence of a hydrogenation catalyst in the solid phase to give 1,1,1,2,3-pentafluoropropane; (ii) dehydrofluorination of the HFC-245eb obtained in stage (i) in the liquid phase using an alkali metal hydroxide or in the gas phase in the presence of a dehydrohalogenation catalyst to give 2,3,3,3-tetrafluoropropene.

(13) The 2,3,3,3-tetrafluoropropene according to the present invention can be obtained from HFP according to a process as described above after a purification of the HFC-245eb and/or after purification of the 2,3,3,3-tetrafluoropropene.

(14) Thus, the HFC-245eb, prior to the dehydrofluorination stage, is, for example, purified by distillation at an absolute pressure of 6 bar and at a column bottom temperature of 80 C. and a top temperature of 50 C. with approximately 30 theoretical plates and a reflux ratio of approximately 37.

(15) After the final dehydrofluorination stage, the HFO-1234yf is subjected to double distillation. The first distillation is carried out at an absolute pressure of approximately 13 bar, a column bottom temperature of approximately 60 C. and a top temperature of approximately 40 C. and with approximately 35 theoretical plates and a reflux ratio of approximately 500. The second distillation is carried out at an absolute pressure of approximately 11 bar, a column bottom temperature of approximately 105 C., and a top temperature of approximately 44 C. and with approximately 30 theoretical plates at a reflux ratio of approximately 4.

(16) The 2,3,3,3-tetrafluoropropene can also be obtained from 1,1,1-trifluoro-2-chloropropene by hydrofluorination in the liquid or gas phase in the presence of a fluorination catalyst. The 2,3,3,3-tetrafluoropropene thus obtained can be purified to give the 2,3,3,3-tetrafluoropropene according to the present invention.

(17) The compositions according to the present invention are capable of being used as heat transfer agent in stationary or motor-vehicle air conditioning, refrigeration and heat pumps.

(18) Another subject-matter of the present invention is the compositions as described above in combination with a lubricant.

(19) Mention may in particular be made, as lubricant, of polyol esters (POEs), polyalkylene glycols (PAGs), polyalkylene glycol esters and polyvinyl ethers (PVEs).

(20) The PAG lubricants are in the oxyalkylene homo- or copolymer form. The preferred PAGs are homopolymers composed of oxypropylene groups with a viscosity of 10 to 200 centistokes at 40 C., advantageously between 30 and 80 centistokes. The hydroxyl groups at the ends of the oxyalkylene homo- or copolymer chains can be more or less replaced by OC.sub.nH.sub.2n+1 groups where n=1 to 10; the group with n=1 being preferred. The PAGs which may be suitable are those having hydroxyl groups for each ending or OC.sub.nH.sub.2n+1 groups.

(21) Mention may in particular be made, as POEs, of esters of carboxylic acids having a linear or branched carbon chain of 2 to 15 atoms and of polyols having a neopentyl backbone, such as neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol; pentaerythritol is the preferred polyol. Esters of carboxylic acids having a carbon chain of 4 to 9 atoms are preferred.

(22) Mention may in particular be made, as carboxylic acid of 4 to 9 carbon atoms, of n-pentanoic acid, n-hexanoic acid, n-heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, 2,2-dimethylpentanoic acid, 3,5,5-trimethylhexanoic acid, adipic acid and succinic acid.

(23) Some alcohol functional groups are not esterified; however, the proportion remains low.

(24) The POE oils selected can comprise between 0 and 5 relative mol % of CH.sub.2OH units with respect to the CH.sub.2O(CO) units.

(25) The preferred POE lubricants are those having a viscosity of 1 to 1000 centistokes (cSt) at 40 C., preferably of 10 to 200 cSt and advantageously of 30 to 80 cSt.

EXPERIMENTAL PART

(26) The thermal stability trials are carried out according to Standard ASHRAE 97-2007: sealed glass tube method to test the chemical stability of materials for use within refrigerant systems.

(27) The test conditions are as follows:

(28) Weight of fluid: 2.2 g

(29) Weight of lubricant: 5 g

(30) Temperature: 200 C.

(31) Duration: 14 days

(32) Lengths of steel are introduced into tubes.

(33) The length of steel and the lubricant are introduced into a 42.2 ml glass tube. The tube is subsequently evacuated under vacuum and then the fluid F is added thereto. The tube is then welded in order to close it and placed in an oven at 200 C. for 14 days.

(34) At the end of the test, various analyses are carried out: the gas phase is recovered in order to be analyzed by gas chromatography: the main impurities were identified by GC/MS (coupled gas chromatography/mass spectrometry). The impurities coming from the fluid F and those coming from the lubricant can thus be combined. the length of steel is weighed (measurement of the rate of corrosion) and observed under a microscope. the lubricant is analyzed: color (by spectrocolorimetry, Labomat DR Lange LICO220 model MLG131), water content (by Karl Fischer coulometry, Mettler DL37) and acid number (by quantitative determination with 0.01N methanolic potassium hydroxide).

(35) The lubricant used in the tests is a commercial PAG oil: PAG ND8.

(36) The fluid used for these trials comprises essentially HFO-1234yf (at least 99.9% by weight) and then 300 ppm of HFO-1243zf, 500 ppm of E HFO-1234ze and 300 ppm of HFO-1243zf+500 ppm of E HFO-1234ze are respectively added to the fluid.

(37) TABLE-US-00001 Content of ppm ppm ppm ppm E HFO- 500 500 1234ze added HFO- 300 300 1243zf added Byproducts in the gas phase: from the 600 ppm 600 ppm 900 ppm 900 ppm HFO-1234yf from the oil 1.4% 1.4% 1.4% 1.4% Rate of <5 m/year <5 m/year <5 m/year <5 m/year corrosion Analysis of the oil: color 10 Gardner 9 Gardner 8.5 Gardner 9 Gardner water content 300 ppm 300 ppm 250 ppm 300 ppm acid number 5.2 mg 5.2 mg 4.5 mg 5.2 mg KOH/g KOH/g KOH/g KOH/g

(38) The examples show that the presence of the compounds (Ia) is not harmful to the thermal stability, either of the HFO-1234yf composition or of the lubricant, and in some cases improves it.