Purification of 2,3,3,3-tetrafluoropropene
Alumina-based adsorbents, promoted with alkali metal oxides, effectively purify 2,3,3,3-tetrafluoropropene by reducing impurities to trace levels, overcoming the limitations of traditional distillation methods.
Patent Information
- Authority / Receiving Office
- AU · AU
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2026-07-16
AI Technical Summary
Existing methods struggle to efficiently purify 2,3,3,3-tetrafluoropropene (1234yf) compositions due to the difficulty in removing impurities such as 1225zc and HFP, especially at high purity levels, with distillation methods being particularly ineffective.
A process involving the use of alumina-based adsorbents, optionally promoted with alkali metal oxides like sodium oxide, to contact and adsorb 1234yf mixtures, maintaining the liquid phase at suitable temperatures and pressures to effectively reduce impurities like 1225zc and HFP to very low concentrations.
The process achieves 1234yf purity levels of at least 99.9% with impurities 1225zc and HFP reduced to less than 0.02% or undetectable levels, demonstrating superior purification efficiency compared to other adsorbents.
Abstract
Description
[0020] The present invention relates to purifying compositions comprising 1234yf and certain undesired components.
[0021] The present disclosure provides a process comprising: contacting a mixture comprising 2,3,3,3-tetrafluoropropene and at least one impurity with an alumina-based adsorbent. In certain embodiments, the alumina-based adsorbent is an alumina loaded with alkali metal oxide, such as sodium oxide (Na2O). In certain embodiments of the process of this disclosure, the alumina-based adsorbent is an alumina not loaded with alkali metal oxide.
[0022] The mixture to be treated typically comprises at least 98% or at least 99% or at least 99.5% or at least 99.8% or at least 99.9% of 1234yf, based on the total weight of said mixture.
[0023] The process of contacting may be performed by simply combining the mixture comprising 1234yf and the at least one undesired component in any suitable vessel at any suitable temperature and pressure, provided however, the contacting is performed at conditions of temperature and pressure to maintain the mixture in the liquid phase. Conveniently the contacting step may be performed at room temperature in a suitable vessel such as a cylinder. Alternatively, the contacting step may be performed by flowing the mixture through an adsorption bed in a continuous process.
[0024] In one embodiment, the mixture to be treated comprises 1234yf and 1225zc. In one embodiment, the mixture to be treated comprises 1234yf and HFP. In one embodiment, the mixture to be treated comprises 1234yf and 1225zc and HFP.
[0025] In certain embodiments, the process comprises contacting a mixture comprising 1234yf and at least one impurity chosen from 1225zc and HFP with an adsorbent, wherein the adsorbent comprises an alumina-based adsorbent.
[0026] In one embodiment, the process comprises contacting a mixture comprising 1234yf and at least one impurity chosen from 1225zc and HFP with an alumina-based adsorbent, wherein the at least one impurity is 1225zc, wherein the alumina-based adsorbent is promoted with an alkali metal oxide, or alternatively, the alumina-based adsorbent is not promoted with an alkali metal oxide.
[0027] In one embodiment, the process comprises contacting a mixture comprising 1234yf and at least one impurity chosen from 1225zc and HFP with an alumina-based adsorbent, wherein the at least one impurity is HFP, wherein the alumina-based adsorbent is promoted with an alkali metal oxide, or alternatively, the alumina-based adsorbent is not promoted with an alkali metal oxide.
[0028] In one embodiment, the process comprises contacting a mixture comprising 1234yf and at least one impurity chosen from 1225zc and HFP with an alumina-based adsorbent, wherein the at least one impurity is 1225zc and HFP, wherein the alumina-based adsorbent is promoted with an alkali metal oxide, or alternatively, the alumina-based adsorbent is not promoted with an alkali metal oxide.
[0029] The alkali metal oxide can be, for example, sodium oxide.
[0030] The amount of adsorbent can be any amount suitable to achieve the desired reduction in the impurities present in the mixture comprising 1234yf.
[0031] The ratio of the mixture comprising 1234yf and at least one impurity chosen from 1225zc and HFP, to the adsorbent is typically in the range of 50:1 to 1:1, preferably 30:1 to 2:1, more preferably 20:1 to 3:1.
[0032] The temperature may range from -30°C to 50°C, preferably -20°C to 40°C, with pressure at the vapor pressure of 1234yf or pressure above such vapor pressure at the selected temperature to maintain a liquid phase.
[0033] Removing impurities from a mixture where the mixture has a purity of at least 98% or at least 99% or at least 99.5% or at least 99.8% or at least 99.9% of 1234yf can be particularly difficult using distillation methods.
[0034] In particular, with respect to certain impurities such as 1225zc and HFP, it is desirable to have very low concentrations. In certain embodiments, the process provides a product comprising 1234yf and less than 0.02% of 1225zc. In certain embodiments, the process provides a product comprising 1234yf and less than 0.01% or less than 0.005% or non-detectable concentration (less than 0.1 ppm) of HFP.
[0035] In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.02% or less of 1225zc. In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.015% or less of 1225zc. In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.01% or less of 1225zc. In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.00001% or less of 1225zc (0.1 ppm, not detectable, “ND”).
[0036] In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.01% or less of HFP. In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.005% or less of HFP. In another embodiment of this invention is provided a composition comprising at least 99.9% of 1234yf and 0.00001% or less of HFP (0.1 ppm, not detectable, “ND”). EXAMPLES
[0037] General Procedure for Purification. 50 g of 1234yf was mixed with a 5 g pre-dried adsorbent at room temperature in a pre-dried cylinder. The mixture was shaken for a few minutes and then held at room temperature for 2 hours, then the liquid phase of the 1234yf mixture was analyzed by GC-MS-FID. At 24 hours after mixing, the liquid phase of 1234yf was analyzed by GC-MS-FID again to check the composition change. The drying conditions for each adsorbent are listed in Table 2. Table 2 Adsorbent Drying conditions Johnson Matthey Puraspec™ 6259 zeolite dried at 90°C for 8 hrs. then ramped to 200°C and hold at 200°C for 2 hours in He before use Johnson Matthey Puraspec™ 3110 alkali promoted alumina adsorbent used as received Adsorbent Drying conditions BASF CL750 AI2O3 based adsorbent dried at 90°C for 8 hrs. then ramped to 200°C and held at 200°C for 2 hours in He before use BASF HF-200 AI2O3 dried at 250°C for 4 hrs. in He , then cooled down to room temperature with He purge BASF HF-200XP AI2O3 dried at 250°C for 4 hrs. in He , then cooled down to room temperature with He purge BASF 4126 AI2O3 dried at 250°C for 4 hrs. then cooled down to room temperature under He before use BASF 3954 AI2O3 dried at 250°C for 4 hrs. then cooled down to room temperature under He before use Molecular sieve 13X dried at 320°C with He purge for 16 hrs., then cooled down to room temperature with He purge Example 1. 1225zc and HFP removal by AI2O3 based adsorbents.
[0038] The starting material composition is provided below, with each of Tables 2a, 2b, 2c, 2d, 2e, and 2f. The results of analyses before and after the tests with AI2O3 based adsorbents are summarized in Tables 2a, 2b, 2c, 2d, 2e, and 2f. The 1225zc and HFP level in 1234yf was reduced significantly with these AI2O3 based adsorbents. Table 2a Starting material BASF AI3954 AI2O3 2hr 24hr HFP 0.0116% 0.0076% 0.0016% 1234yf 99.9357% 99.9444% 99.9575% 1225zc 0.0201% 0.0174% 0.0086% Z-1225ye 0.0113% 0.0125% 0.0124% E-1234ze 0.0144% 0.0155% 0.0156% 152a 0.0029% 0.0027% 0.0025% 124 0.0017% 0.0017% 0.0018% Table 2b Starting material BASF AI4126 AI2O3 2hr 24hr HFP 0.0116% 0.0115% 0.0074% 1234yf 99.9357% 99.9351% 99.9412% 1225zc 0.0201% 0.0207% 0.0179% Z-1225ye 0.0113% 0.0115% 0.0118% E-1234ze 0.0144% 0.0146% 0.0147% 152a 0.0029% 0.0027% 0.0027% 124 0.0017% 0.0019% 0.0020% Table 2c Starting material JM 3110 Na2O / AI2O3 2hr 24hr HFP 0.0116% 0.0034% ND 1234yf 99.9357% 99.9542% 99.9672% 1225zc 0.0201% 0.0106% ND Z-1225ye 0.0113% 0.0109% 0.0113% E-1234ze 0.0144% 0.0140% 0.0147% 152a 0.0029% 0.0029% 0.0030% 124 0.0017% 0.0016% 0.0018% Table 2d Starting material BASF CL750 AI2O3 2hr 24 hr HFP 0.0116% 0.0033% ND 1234yf 99.9357% 99.9500% 99.9655% 1225zc 0.0201% 0.0105% ND Z-1225ye 0.0113% 0.0118% 0.0116% E-1234ze 0.0144% 0.0149% 0.0149% 152a 0.0029% 0.0027% 0.0027% 124 0.0017% 0.0017% 0.0019% Table 2e Starting material BASF HF-200 AI2O3 2hr 24 hr HFP 0.0116% 0.0087% 0.0022% 1234yf 99.9357% 99.9344% 99.9533% 1225zc 0.0201% 0.0186% 0.0113% Z-1225ye 0.0113% 0.0117% 0.0116% E-1234ze 0.0144% 0.0149% 0.0145% 152a 0.0029% 0.0028% 0.0027% 124 0.0017% 0.0018% 0.0018% Table 2f Starting material BASF HF-200XP AI2O3 2hr 24hr HFP 0.0116% 0.0116% 0.0093% 1234yf 99.9357% 99.9337% 99.9421% 1225zc 0.0201% 0.0207% 0.0173% Z-1225ye 0.0113% 0.0116% 0.0121% E-1234ze 0.0144% 0.0152% 0.0148% 152a 0.0029% 0.0028% 0.0028% 124 0.0017% 0.0020% 0.0016% Example 2. Comparison : Treatment of 1234yf containing 1225zc and HFP with zeolite-based adsorbents.
[0039] The starting material composition is provided below, with each of Tables 3a and 3b. The results of analyses before and after the tests with zeolite-based adsorbents are summarized in Tables 3a and 3b. The zeolite-based adsorbents did not reduce the concentrations of 1225zc and HFP as did the alumina-based adsorbents. Table 3a Starting material Zeolite 13X 2hr 24hr 7 days HFP 0.0116% 0.0118% 0.0114% 0.0114% 1234yf 99.9357% 99.9365% 99.9364% 99.9364% 1225zc 0.0201% 0.0208% 0.0206% 0.0206% Z-1225ye 0.0113% 0.0116% 0.0116% 0.0116% E-1234ze 0.0144% 0.0143% 0.0143% 0.0143% 152a 0.0029% 0.0012% 0.0011% 0.0011% 124 0.0017% 0.0017% 0.0016% 0.0016% Table 3b Starting material JM6259 Puraspec™ zeolite 2hr 24hr HFP 0.0116% 0.0118% 0.0121% 1234yf 99.9357% 99.9353% 99.9370% 1225zc 0.0201% 0.0206% 0.0196% Z-1225ye 0.0113% 0.0117% 0.0115% E-1234ze 0.0144% 0.0143% 0.0141% 152a 0.0029% 0.0011% 0.0011% 124 0.0017% 0.0015% 0.0017%
Claims
1. A process for removing an impurity from a fluoroolefin mixture comprising 2,3,3,3-tetrafluoropropene and at least one impurity wherein the process comprises contacting the fluoroolefin mixture with an alumina-based adsorbent in the liquid phase to reduce the concentration of the at least one impurity chosen from 1,1,3,3,3-pentafluoropropene and hexafluoropropene.
2. The process of claim 1 wherein the alumina-based adsorbent is an AI2O3 adsorbent.
3. The process of claim 1 wherein the alumina-based adsorbent is an alkali promoted alumina adsorbent.
4. The process of claim 3 wherein the alumina-based adsorbent is an alumina loaded with alkali metal oxide.
5. The process of claim 4 wherein the alkali metal oxide is sodium oxide.
6. The process of claim 1 wherein the alumina-based adsorbent is an alumina notloaded with alkali metal oxide.
7. The process of any of claims 1-6 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene.
8. The process of any of claims 1-6 wherein the one or more of impurities comprises hexafluoropropene.
9. The process of any of claims 1-6, wherein the one or more of impurities comprises 1,3,3,3-pentafluoropropene and hexafluoropropene.
10. The process of claim 3 wherein the one or more of impurities comprises1,1,3,3,3-pentafluoropropene.
11. The process of claim 3 wherein the one or more of impurities comprises hexafluoropropene.
12. The process of claim 3 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene and hexafluoropropene.
13. The process of claim 4 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene.
14. The process of claim 4 wherein the one or more of impurities comprises hexafluoropropene.
15. The process of claim 4 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene and hexafluoropropene.
16. The process of claim 5 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene.
17. The process of claim 5 wherein the one or more of impurities comprises hexafluoropropene.
18. The process of claim 5 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene and hexafluoropropene.
19. The process of claim 6 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene.
20. The process of claim 6 wherein the one or more of impurities comprises hexafluoropropene.
21. The process of claim 6 wherein the one or more of impurities comprises 1,1,3,3,3-pentafluoropropene and hexafluoropropene.
22. The process of any of claims 1-21 wherein the amount of 2,3,3,3-tetrafluoropropene in said mixture is at least 98 wt % based on the total weight of said mixture.
23. A composition comprising at least 99.9% of 2,3,3,3-tetrafluoropropene and 0.02% or less of 1,1,3,3,3-pentafluoropropene.
24. The composition of claim 23, wherein the composition comprises 0.015% or less of 1,1,3,3,3-pentafluoropropene.
25. The composition of claim 23, wherein the composition comprises 0.00001% or less of 1,1,3,3,3-pentafluoropropene.
26. A composition comprising at least 99.9% of 2,3,3,3-tetrafluoropropene and 0.01% or less of hexafluoropropene.
27. The composition of claim 26, wherein the composition comprises 0.005% or less of hexafluoropropene.
28. The composition of claim 26, wherein the composition comprises 0.00001% or less of hexafluoropropene.