METHOD OF PRODUCING MONOFLUOROMETHANE

Abstract

Provided is a production method that enables production of monofluoromethane by a gas phase flow method without using a catalyst. The method of producing monofluoromethane includes causing electrical discharge of a feedstock gas containing a fluorine-containing inorganic compound, a compound represented by formula 1: CH.sub.3—R (R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group other than a hydrocarbon group), and an inert gas, while in a continuous flow state, and then causing continuous release to outside of an electrical discharge zone.

Claims

1. A method of producing monofluoromethane comprising causing electrical discharge of a feedstock gas containing: a fluorine-containing inorganic compound; a compound represented by formula 1: CH.sub.3—R, where R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group other than a hydrocarbon group; and an inert gas, while in a continuous flow state, and then causing continuous release to outside of an electrical discharge zone.

2. The method of producing monofluoromethane according to claim 1, wherein the fluorine-containing inorganic compound is one or more selected from the group consisting of SF.sub.4, SF.sub.6, SOF.sub.2, SO.sub.2F.sub.2, HF, NF.sub.3, CF.sub.4, BF.sub.3, and SiF.sub.4.

3. The method of producing monofluoromethane according to claim 1, wherein the inert gas is one or more selected from the group consisting of N.sub.2 and Ar.

4. The method of producing monofluoromethane according to claim 1, wherein total proportional content of the fluorine-containing inorganic compound and the compound represented by formula 1 in the feedstock gas is not less than 1 volume % and not more than 85 volume %.

5. The method of producing monofluoromethane according to claim 1, wherein a volume ratio of the fluorine-containing inorganic compound relative to the compound represented by formula 1 is 0.8 or more.

6. The method of producing monofluoromethane according to claim 1, wherein a volume ratio of the fluorine-containing inorganic compound relative to the compound represented by formula 1 is 1.8 or more.

Description

EXAMPLES

[0049] The present disclosure is described in more detail below through examples. However, the present disclosure is not limited by these examples.

Example 1

[0050] CH.sub.3OH (vapor) as a compound of formula 1, SF.sub.6 as a fluorine-containing inorganic compound, and Ar as an inert gas were introduced at flow rates of 10 sccm, 5 sccm, and 285 sccm, respectively, into a gas phase flow reaction tube made of metal in which parallel plate electrodes capable of high-frequency discharge were installed (frequency: 60 MHz, capacity: 35 L).

[0051] Electrical discharge was caused to occur through 500 W of supplied electrical power while holding a mixed gas of the compound of formula 1, the fluorine-containing inorganic compound, and the inert gas at 10 PaA (absolute pressure) inside the reaction tube. Gas was continuously released from the reaction tube and was trapped in an aluminum bag. A neutralization tube filled with KOH pellets was installed before the aluminum bag such that the trapped gas was gas that had passed through the neutralization tube.

[0052] The trapped gas was analyzed by gas chromatography-mass spectrometry (GC-MS) (Agilent 7890A produced by Agilent Technologies, Inc.) and flame ionization detection gas chromatography (GC-FID) (Agilent 6890N produced by Agilent Technologies, Inc.). The molar conversion rate of the compound of formula 1 was determined from area values for components in GC-FID and GC-MS that were obtained through the analysis, and this molar conversion rate was taken to be the feedstock conversion rate. In addition, the molar selectivity of CH.sub.3F (monofluoromethane) in the product was determined from the aforementioned area values. The results are shown in Table 1.

Example 2

[0053] Example 2 is the same as Example 1 with the exception that the flow rates of CH.sub.3OH, SF.sub.6, and Ar were changed to 10 sccm, 20 sccm, and 270 sccm, respectively. The results are shown in Table 1.

Example 3

[0054] Example 3 is the same as Example 1 with the exception that the flow rates of CH.sub.3OH, SF.sub.6, and Ar were changed to 10 sccm, 30 sccm, and 260 sccm, respectively. The results are shown in Table 1.

Example 4

[0055] Example 4 is the same as Example 1 with the exception that the flow rates of CH.sub.3OH, SF.sub.6, and Ar were changed to 10 sccm, 50 sccm, and 240 sccm, respectively. The results are shown in Table 1.

Example 5

[0056] Example 5 is the same as Example 1 with the exception that the flow rates of CH.sub.3OH, SF.sub.6, and Ar were changed to 10 sccm, 240 sccm, and 50 sccm, respectively. The results are shown in Table 1.

Example 6

[0057] Example 6 is the same as Example 3 with the exception that the inert gas was changed from Ar to N.sub.2. The results are shown in Table 1.

Example 7

[0058] Example 7 is the same as Example 1 with the exception that CH.sub.4 was used as the compound of formula 1 and that the flow rates of CH.sub.4, SF.sub.6, and Ar were changed to 10 sccm, 30 sccm, and 260 sccm, respectively. The results are shown in Table 1.

Example 8

[0059] Example 8 is the same as Example 7 with the exception that the flow rates of CH.sub.4, SF.sub.6, and Ar were changed to 10 sccm, 50 sccm, and 240 sccm, respectively. The results are shown in Table 1.

Example 9

[0060] Example 9 is the same as Example 7 with the exception that the inert gas was changed from Ar to N.sub.2. The results are shown in Table 1.

Example 10

[0061] Example 10 is the same as Example 1 with the exception that CH.sub.3OH was used as the compound of formula 1, CF.sub.4 was used as the fluorine-containing inorganic compound, and the flow rates of CH.sub.3OH, CF.sub.4, and Ar were changed to 10 sccm, 10 sccm, and 280 sccm, respectively. The results are shown in Table 1.

Example 11

[0062] Example 11 is the same as Example 1 with the exception that CH.sub.3COCH.sub.3 was used as the compound of formula 1 and that the flow rates of CH.sub.3COCH.sub.3, SF.sub.6, and Ar were changed to 10 sccm, 50 sccm, and 240 sccm, respectively. The results are shown in Table 1.

Example 12

[0063] Example 12 is the same as Example 1 with the exception that CH.sub.3OCH.sub.3 was used as the compound of formula 1 and that the flow rates of CH.sub.3OCH.sub.3, SF.sub.6, and Ar were changed to 10 sccm, 50 sccm, and 240 sccm, respectively. The results are shown in Table 1.

Example 13

[0064] Example 13 is the same as Example 1 with the exception that CH.sub.3Cl was used as the compound of formula 1 and that the flow rates of CH.sub.3Cl, SF.sub.6, and Ar were changed to 10 sccm, 50 sccm, and 240 sccm, respectively. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Proportional content of compound of Volume ratio formula 1 and of fluorine- fluorine- containing Feed- Hydro- containing inorganic stock CH.sub.3F carbon Fluorine- inorganic compound conver- selec- selec- Compound Flow containing Flow Flow compound in relative Space sion rate tivity tivity of rate inorganic rate Inert rate feedstock gas to compound velocity [mol [mol [mol Examples formula 1 [sccm] compound [sccm] gas [sccm] [volume %] of formula 1 [h.sup.−1] %] %] %] Example 1 CH.sub.3OH 10 SF.sub.6 5 Ar 285  5% 0.5 0.5 75.1% 10.1% 42.4% Example 2 10 20 270 10% 2.0 0.5 72.5% 62.6% 0.9% Example 3 10 30 260 13% 3.0 0.5 78.9% 81.7% 0.4% Example 4 10 50 240 20% 5.0 0.5 82.0% 87.5% 0.7% Example 5 10 240 50 83% 24.0 0.5 76.4% 99.2% 0.8% Example 6 10 30 N.sub.2 260 13% 3.0 0.5 79.2% 62.1% 0.8% Example 7 CH.sub.4 10 SF.sub.6 30 Ar 260 13% 3.0 0.5 72.1% 37.3% — Example 8 10 50 240 20% 5.0 0.5 80.4% 68.4% — Example 9 10 30 N.sub.2 260 13% 3.0 0.5 76.7% 10.8% — Example 10 CH.sub.3OH 10 CF.sub.4 10 Ar 280  7% 1.0 0.5 84.0% 5.2% 8.0% Example 11 CH.sub.3COCH.sub.3 10 SF.sub.6 50 240 20% 5.0 0.5 70.0% 20.6% 2.5% Example 12 CH.sub.3OCH.sub.3 10 50 240 20% 5.0 0.5 72.1% 25.4% 1.6% Example 13 CH.sub.3Cl 10 50 240 20% 5.0 0.5 32.7% 28.0% 1.3%

[0065] It can be seen from Table 1 that monofluoromethane (CH.sub.3F) could be produced without using a catalyst in the examples. It can also be seen that production of hydrocarbon side products was sufficiently inhibited in Examples 2 to 13, in particular, in which the volume ratio of the fluorine-containing inorganic compound relative to the compound of formula 1 was 0.8 or more. It can also be seen through comparison with Example 1 that Examples 2 to 5 in which the volume ratio of the fluorine-containing inorganic compound relative to the compound of formula 1 was 1.8 or more were advantageous in the production of monofluoromethane (CH.sub.3F).

INDUSTRIAL APPLICABILITY

[0066] According to the present disclosure, it is possible to produce monofluoromethane by a gas phase flow method without using a catalyst. The presently disclosed production method makes it possible to avoid reduction of yield caused by reduction of catalyst activity, enables continuous production of monofluoromethane, and has high industrial applicability.