PROCESS FOR PRODUCING 2-CHLORO-3,3,3-TRIFLUOROPROPENE

Abstract

This invention provides a process for producing 2-chloro-3,3,3-trifluoropropene, comprising: reacting anhydrous hydrogen fluoride with at least one chlorine-containing compound selected from the group consisting of chloropropanes and chloropropenes represented by specific formulas in a gas phase in the presence of a chromium atom-containing fluorination catalyst while heating, the reaction being carried out in the presence of molecular chlorine or with a water content in the reaction system of 300 ppm or less. This invention enables suppression of catalyst deterioration and efficient production of 2-chloro-3,3,3-trifluoropropene in a simple and economically advantageous manner on an industrial scale.

Claims

1. A process for producing 2-chloro-3,3,3-trifluoropropene, comprising: continuously reacting anhydrous hydrogen fluoride with at least one chlorine-containing compound in a gas phase in the presence of a chromium atom-containing fluorination catalyst while heating for at least 200 hours, the at least one chlorine-containing compound being chloropropenes represented by Formula (3): CXY═CClCH.sub.2A, wherein X and Y are the same or different and each is F or Cl, and A is a halogen atom, and the reaction being carried out in the presence of molecular chlorine, wherein the amount of molecular chlorine is about 0.001 to about 0.3 moles per mole of the at least one chlorine-containing compound, the reaction being carried out at a temperature in the range of 200° C. to 300° C., the selectivity of the 2-chloro-3,3,3-trifluoropropene being maintained at at least 90% after 200 hours of reaction time, and the conversion rate of the chlorine-containing compound being maintained at at least 80% after 200 hours of reaction time.

2. A process for producing 2-chloro-3,3,3-trifluoropropene, comprising: continuously reacting anhydrous hydrogen fluoride with at least one chlorine-containing compound in a gas phase in the presence of a chromium atom-containing fluorination catalyst while heating for at least 200 hours, the at least one chlorine-containing compound being chloropropenes represented by Formula (3): CXY═CClCH.sub.2A, wherein X and Y are the same or different and each is F or Cl, and A is a halogen atom, and the reaction being carried out with a water content in the reaction system of 300 ppm or less based on the total weight of the at least one chlorine-containing compound used as a starting material with the proviso that the water content in the reaction system is not 0 ppm, and the reaction being carried out on an industrial scale, and the selectivity of the 2-chloro-3,3,3-trifluoropropene being maintained at more than 95% after 200 hours of reaction time.

3. A process for producing 2-chloro-3,3,3-trifluoropropene, comprising: continuously reacting anhydrous hydrogen fluoride with at least one chlorine-containing compound in a gas phase in the presence of a chromium atom-containing fluorination catalyst while heating for at least 200 hours, the at least one chlorine-containing compound being chloropropenes represented by Formula (3): CXY═CClCH.sub.2A, wherein X and Y are the same or different and each is F or Cl, and A is a halogen atom, and the reaction being carried out in the presence of molecular chlorine and with a water content in the reaction system of 300 ppm or less based on the total weight of the at least one chlorine-containing compound used as a starting material with the proviso that the water content in the reaction system is not 0 ppm, wherein the amount of molecular chlorine is about 0.001 to about 0.3 moles per mole of the at least one chlorine-containing compound, the reaction being carried out on an industrial scale, and the selectivity of the 2-chloro-3,3,3-trifluoropropene being maintained at more than 95% after 200 hours of reaction time.

4. (canceled)

5. The process according to claim 4, wherein the amount of molecular chlorine supplied is 0.001 to 0.2 moles per mole of the at least one chlorine-containing compound.

6. The process according to claim 2, wherein the reaction is carried out with a water content in the reaction system of 100 ppm or less based on the total weight of the at least one chlorine-containing compound used as a starting material.

7. The process according to claim 1, wherein the chromium atom-containing fluorination catalyst is at least one catalyst selected from the group consisting of chromium oxides and fluorinated chromium oxides.

8. The process according to claim 7, wherein the fluorination catalyst is at least one catalyst selected from the group consisting of chromium oxides represented by the composition formula: CrO.sub.m (1.5<m<3) and fluorinated chromium oxides obtained by fluorinating the chromium oxides.

9. (canceled)

10. The process according to claim 1, wherein the reaction is carried out using 3 moles or more of anhydrous hydrogen fluoride per mole of the at least one chlorine-containing compound used as a starting material.

11. The process according to claim 1, wherein the at least one chlorine-containing compound used as a starting material is 1,1,2,3-tetrachloropropene.

Description

DESCRIPTION OF EMBODIMENTS

[0084] Hereinafter, the present invention is described in more detail with reference to Examples.

EXAMPLE 1

[0085] 10 g of a catalyst (fluorine content: about 15.0% by weight) obtained by fluorinating a chromium oxide represented by the composition formula: CrO.sub.2 was placed into a tubular Hastelloy reactor with an inner diameter of 15 mm and a length of 1 m. The reactor was maintained at atmospheric pressure (0.1 MPa) and 250° C., and anhydrous hydrogen fluoride (HF) gas having a water content of 50 ppm was supplied to the reactor at a flow rate of 114 mL/min (flow rate at 0° C., 0.1 MPa) for 1 hour. CCl.sub.3CHClCH.sub.2Cl (HCC-240db) having a water content of 40 ppm was then supplied at a flow rate of 5.6 mL/min (gas flow rate at 0° C., 0.1 MPa). The water content in the reaction system at this point based on the weight of HCC-240db was 134 ppm. The molar ratio of HF:HCC-240db was 20:1. The contact time (W/F.sub.0) was 5.0 gsec/cc.

[0086] The outlet gas from the reactor after 20 hours, 100 hours, and 200 hours was analyzed using gas chromatography. Table 1 shows the analysis results.

[0087] Under these conditions, the selectivity of HCFO-1233xf was maintained at a high value: 96.7% after 20 hours, and 93.9% after 200 hours. The rate of decline in the total selectivity of useful compounds of HCFO-1233xf, HFC-245cb, and HFO-1234yf was 0.37%/day; thus, the decline in the selectivity was suppressed.

TABLE-US-00001 TABLE 1 Reaction Time (hr) 20 100 200 Conversion of HCC-240db (%) 99.9 99.4 98.9 Selectivity of HFO-1234yf (%) 0.4 0.2 0.1 Selectivity of HFC-245cb (%) 0.9 0.2 0.0 Selectivity of HCFO-1233xf (%) 96.7 95.8 93.9 Selectivity of HCFO-1232xf (%) 0.3 0.9 1.3 Selectivity of HCO-1230xa (%) 0.2 0.7 1.1 Others (%) 1.5 2.2 3.6

Comparative Example 1

[0088] A reaction was conducted under the same conditions as in Example 1, except that CCl.sub.3CHClCH.sub.2Cl (HCC-240db) having a water content of 250 ppm was supplied. The water content in the reaction system at this point based on the weight of HCC-240db was 340 ppm. Table 2 shows the analysis results of the outlet gas.

[0089] Under these conditions, the selectivity of HCFO-1233xf was 95.6% after 20 hours, and decreased to 89.8% after 200 hours. The total selectivity of useful compounds of HCFO-1233xf, HFC-245 cb, and HFO-1234yf was decreased at 0.77%/day.

TABLE-US-00002 TABLE 2 Reaction time (hr) 20 100 200 Conversion of HCC-240db (%) 99.8 99.2 98.0 Selectivity of HFO-1234yf (%) 0.2 0.1 0.0 Selectivity of HFC-245cb (%) 0.4 0.0 0.0 Selectivity of HCFO-1233xf (%) 95.6 92.9 89.8 Selectivity of HCFO-1232xf (%) 0.5 2.4 4.6 Selectivity of HCO-1230xa (%) 0.5 1.2 1.8 Others (%) 1.5 3.4 3.8

EXAMPLE 2

[0090] A reaction was carried out under the same conditions as in Example 1, except that CCl.sub.3CHClCH.sub.2Cl (HCC-240db) in which 0.008 moles of molecular chlorine per mole of HCC-240db was dissolved was supplied. The water content in the reaction system at this point based on the weight of HCC-240db was 134 ppm. Table 3 shows the analysis results of the outlet gas.

[0091] Under these conditions, the selectivity of HCFO-1233xf was maintained at a high value: 96.1% after 20 hours, and 96.3% after 200 hours. The total selectivity of useful compounds of HCFO-1233xf, HFC-245cb, and HFO-1234yf had a decline rate of 0.03%/day, and was maintained at an almost constant value.

TABLE-US-00003 TABLE 3 Reaction Time (hr) 20 100 200 Conversion of HCC-240db (%) 99.9 100 99.9 Selectivity of HFO-1234yf (%) 0.3 0.3 0.2 Selectivity of HFC-245cb (%) 0.6 0.4 0.3 Selectivity of HCFO-1233xf (%) 96.1 96.2 96.3 Selectivity of HCFO-1232xf (%) 0.2 0.1 0.3 Selectivity of HCO-1230xa (%) 0.2 0.1 0.1 Others (%) 1.6 2.9 5.1

EXAMPLE 3

[0092] CCl.sub.3CHClCH.sub.2Cl (HCC-240db) having a water content of 15 ppm was prepared by adding molecular sieves 4A (100 g) to HCC-240db (1 kg) having a water content of 40 ppm, which was used in Example 1, hermetically sealing the resulting mixture, and allowing the mixture to stand for 24 hours.

[0093] In addition, anhydrous hydrogen fluoride (HF) having a water content of 10 ppm was prepared by placing anhydrous hydrogen fluoride (HF) (800 g) having a water content of 50 ppm, which was used in Example 1, in a 1 L polytetrafluoroethylene container equipped with a reflux condenser and a distillation tube, and heating the container to collect HF.

[0094] A reaction was carried out under the same conditions as in Example 1, except that CCl.sub.3CHClCH.sub.2Cl (HCC-240db) having a water content of 15 ppm and anhydrous hydrogen fluoride (HF) gas having a water content of 10 ppm obtained in the above manner were supplied. The water content in the reaction system at this point based on the weight of HCC-240db was 34 ppm. Table 4 shows the analysis results of the outlet gas.

[0095] Under these conditions, the selectivity of HCFO-1233xf was maintained at a high value: 96.8% after 20 hours and 95.6% after 200 hours. The rate of decline in total selectivity of useful compounds of HCFO-1233xf, HFC-245cb, and HFO-1234yf was 0.24%/day; thus, the decline in the selectivity was suppressed.

TABLE-US-00004 TABLE 4 Reaction Time (hr) 20 100 200 Conversion of HCC-240db (%) 100 99.8 99.5 Selectivity of HFO-1234yf (%) 0.5 0.3 0.2 Selectivity of HFC-245cb (%) 0.7 0.6 0.4 Selectivity of HCFO-1233xf (%) 96.8 96.1 95.6 Selectivity of HCFO-1232xf (%) 0.3 0.6 1.0 Selectivity of HCO-1230xa (%) 0.2 0.5 0.8 Others (%) 1.5 1.9 2.0

EXAMPLE 4

[0096] A reaction was carried out under the same conditions as in Comparative Example 1, except that chlorine gas was supplied at 0.14 mL/min (gas flow rate at 0° C., 0.1 MPa) concurrently with supply of CCl.sub.3CHClCH.sub.2Cl (HCC-240db). The water content in the reaction system at this point based on the weight of HCC-240db was 340 ppm. Table 5 shows the analysis results of the outlet gas.

[0097] Under these conditions, the selectivity of HCFO-1233xf was maintained at a high value: 96.2% after 20 hours, and 95.3% after 200 hours. The rate of decline in total selectivity of useful compounds of HCFO-1233xf, HFC-245cb, and HFO-1234yf was 0.11%/day; thus, the decline in the selectivity was suppressed.

TABLE-US-00005 TABLE 5 Reaction Time (hr) 20 100 200 Conversion of HCC-240db (%) 100 100 100 Selectivity of HFO-1234yf (%) 0.2 0.1 0.1 Selectivity of HFC-245cb (%) 0.3 0.2 0.2 Selectivity of HCFO-1233xf (%) 96.2 95.9 95.3 Selectivity of HCFO-1232xf (%) 0.1 0.2 0.3 Selectivity of HCO-1230xa (%) 0.0 0.1 0.2 Others (%) 3.2 3.4 3.9

EXAMPLE 5

[0098] A reaction was carried out under the same conditions as in Example 1, except that chlorine gas was supplied at 0.14 mL/min (gas flow rate at 0° C., 0.1 MPa) concurrently with supply of CCl.sub.3CHClCH.sub.2Cl (HCC-240db). At this point, the molar ratio of Cl.sub.2:HCC-240db was 0.025:1, and the water content in the reaction system based on the weight of HCC-240db was 134 ppm. Table 6 shows the analysis results of the outlet gas.

[0099] Under these conditions, the selectivity of HCFO-1233xf was maintained at a high value: 94.8% after 20 hours and 94.0% after 200 hours. The total selectivity of useful compounds of HCFO-1233xf, HFC-245cb, and HFO-1234yf had a decline rate of 0.09%/day, and was maintained at an almost constant value.

TABLE-US-00006 TABLE 6 Reaction Time (hr) 20 100 200 Conversion of HCC-240db (%) 100 100 100 Selectivity of HFO-1234yf (%) 0.3 0.2 0.1 Selectivity of HFC-245cb (%) 0.4 0.2 0.0 Selectivity of HCFO-1233xf (%) 94.8 94.5 94.0 Selectivity of HCFO-1232xf (%) 0.1 0.2 0.3 Selectivity of HCO-1230xa (%) 0.0 0.0 0.2 Others (%) 4.4 4.9 5.4

Comparative Example 2

[0100] 20 g of a catalyst (fluorine content: about 15.0% by weight) obtained by fluorinating a chromium oxide represented by the composition formula: CrO.sub.2 was placed into a tubular Hastelloy reactor with an inner diameter of 15 mm and a length of 1 m. The reaction tube was maintained at atmospheric pressure (0.1 MPa) and 250° C., and anhydrous hydrogen fluoride (HF) gas was supplied to the reactor at a flow rate of 114 mL/min (flow rate at 0° C., 0.1 MPa) for 1 hour. After the flow rate of HF was adjusted to 76 mL/min, CCl.sub.2═CClCH.sub.2Cl (HCO-1230xa) having a water content of 240 ppm was supplied at a flow rate of 3.8 mL/min (gas flow rate at 0° C., 0.1 MPa). The water content in the reaction system at this point based on the weight of HCO-1230xa was 330 ppm. The molar ratio of HF:HCO-1230xa was 20:1, and the contact time (W/F.sub.0) was 15.0 gsec/cc.

[0101] The outlet gas from the reactor after 40 hours, 70 hours, and 110 hours was analyzed using gas chromatography. Table 7 shows the analysis results.

[0102] Under these conditions, the conversion of HCO-1230xa was 85.2% after 40 hours, and decreased to 50.0% after 110 hours. Additionally, the yield (conversion x selectivity) of HCFO-1233xf was 75.5% after 40 hours, and decreased to 23.0% after 110 hours. Moreover, the total yield of useful compounds of HCFO-1233xf, HFC-2450b, and HFO-1234yf was also decreased at 18.0%/day.

TABLE-US-00007 TABLE 7 Reaction Time (hr) 40 70 110 Conversion of HCO-1230xa (%) 85.2 68.8 50.0 Selectivity of HFO-1234yf (%) 0.0 0.0 0.0 Selectivity of HFC-245cb (%) 0.0 0.0 0.0 Selectivity of HCFO-1233xf (%) 88.6 76.7 46.0 Selectivity of HCFO-1232xf (%) 8.4 17.3 26.9 Others (%) 3.0 6.0 27.1

EXAMPLE 6

[0103] A reaction was carried out under the same conditions as in Comparative Example 2, except that chlorine gas was supplied at 0.12 mL/min (gas flow rate at 0° C., 0.1 MPa) concurrently with supply of CCl.sub.2═CClCH.sub.2Cl (HCO-1230xa). At this point, the water content in the reaction system based on the weight of HCO-1230xa was 340 ppm, and the molar ratio of Cl.sub.2:HCO-1230xa was 0.032:1. Table 8 shows the analysis results of the outlet gas.

[0104] Under these conditions, the conversion of HCO-1230xa was maintained at a high value: 92.9% after 25 hours and 84.3% after 100 hours; the yield of HCFO-1233xf was also maintained at a high value: 88.4% after 25 hours, and 78.0% after 100 hours. In addition, the rate of decline in the total yield of useful compounds of HCFO-1233xf, HFC-2450b, and HFO-1234yf was 3.4%/day, and the deterioration of catalytic activity was reduced by the supply of chlorine gas.

TABLE-US-00008 TABLE 8 Reaction Time (hr) 25 70 100 Conversion of HCO-1230xa (%) 92.9 88.0 84.3 Selectivity of HFO-1234yf (%) 0.2 0.2 0.1 Selectivity of HFC-245cb (%) 0.3 0.2 0.2 Selectivity of HCFO-1233xf (%) 95.2 93.7 92.6 Selectivity of HCFO-1232xf (%) 1.8 3.0 3.8 Others (%) 2.5 2.9 3.3