JPWO2014208452A1 - Method for producing trifluoroethylene - Google Patents

Abstract

By-products that are easy to procure, without the use of catalysts, industrially useful HFO-1123 in synthetic reactions involving thermal decomposition, and by-products that are difficult to separate by distillation from HFO-1123, especially HFO An economically advantageous method for producing a high purity by suppressing the formation of -1132 (E). A method for producing HFO-1123 from TFE and R31 by a synthetic reaction involving thermal decomposition, wherein (a) the TFE and R31 are mixed in advance or separately supplied to a reactor; b) supplying a heat medium to the reactor; and (c) in the reactor, the temperature in the reactor is controlled at 400 to 950 ° C., and the tetrafluoroethylene, the chlorofluoromethane, and the And a step of bringing the trifluoroethylene into contact with a heat medium.

Description

  The present invention relates to a method for producing trifluoroethylene, and relates to a method for producing trifluoroethylene using tetrafluoroethylene and chlorofluoromethane as raw materials.

  In the present specification, for halogenated hydrocarbons, the abbreviations of the compounds are shown in parentheses after the compound names. In this specification, the abbreviations are used instead of the compound names as necessary. Since trifluoroethylene (HFO-1123) has a low global warming potential (GWP), it is a greenhouse gas such as difluoromethane (HFC-32) or 1,1,1,2,2-pentafluoroethane (HFC-). In recent years, great expectations have been given as a new refrigerant replacing 125).

  As a method for producing HFO-1123, chlorotrifluoroethylene (CTFE) is reduced with hydrogen in the presence of a palladium or platinum catalyst (for example, see Patent Document 1), 1,1,1,2-tetra. A method of dehydrofluorination using a metal fluoride or the like in which fluoroethane (HFC-134a) or 1,1,2,2-tetrafluoroethane (HFC-134) is supported on a carrier such as aluminum oxide as a catalyst (for example, Patent Document 2), a method of reducing 1,1,2-trichloro-1,2,2-trifluoroethane with hydrogen in the presence of a catalyst such as palladium (for example, see Patent Document 3), and the like are known. ing.

  However, in the production method using the catalyst process described in Patent Literatures 1 to 3, catalyst preparation, replacement of the catalyst in the catalyst-filled reactor accompanying catalyst deactivation, catalyst discard or reactivation, There are many economic disadvantages such as possible clogging with the product and long reaction times. Moreover, in any of the methods shown in Patent Document 1 and Patent Document 3, the amount of by-products generated by excessive hydrogen reduction is increased, and a sufficiently high yield of high-purity HFO-1123 is obtained. Could not get in.

International Publication 2012/000853 JP 2010-533151 A JP-A-9-104647

  As a result of repeated studies by the present inventors, in both methods shown in Patent Document 1 and Patent Document 3, hydrogen reduction proceeds excessively, and E-1,2-difluoroethylene (HFO-1132 (EFO )) Was generated. According to the present inventors, this HFO-1132 (E) has a boiling point very close to that of HFO-1123, and thus it is difficult to distill and separate them. And under certain conditions, this HFO-1132 ( It was found that the by-product of E) can be suppressed.

  The present invention has been made from the above viewpoint, and uses HFO-1123, which is industrially useful in a synthesis reaction involving thermal decomposition, without using a catalyst, using raw materials that are easily procured, and HFO-1123. It is an object of the present invention to provide an economically advantageous method for efficiently producing a high purity by suppressing the formation of by-products which are difficult to separate by distillation, particularly HFO-1132 (E).

The present invention is a method for producing trifluoroethylene (HFO-1123) from tetrafluoroethylene (TFE) and chlorofluoromethane (R31),
(A) mixing the TFE and the R31 in advance or separately supplying them to the reactor;
(B) supplying a heat medium to the reactor;
(C) In the reactor, the temperature in the reactor is controlled at 400 to 950 ° C., and the TFE, the R31, and the heat medium are brought into contact with each other to generate the HFO-1123. A method for producing HFO-1123 is provided.

  According to the production method of the present invention, TFE and R31, which are easy to procure, are used as raw materials, and a synthesis reaction involving thermal decomposition controlled at a specific temperature without using a catalyst. HFO-1123 that is industrially useful as a small new refrigerant can be efficiently produced.

  According to the production method of the present invention, since the boiling point is close, the production of by-products that are very difficult to separate can be suppressed, and high-purity HFO-1123 can be obtained. That is, among the by-products, RHFO-1132 (E) has a boiling point of −51 ° C. and very close to that of HFO-1123 (−54 ° C.). Although difficult, according to the production method of the present invention, it is possible to produce by high purity while suppressing the formation of by-products that are difficult to be separated by distillation from HFO-1123 such as HFO-1132 (E).

According to the production method of the present invention, by using a heat medium, it is easy to control production (reaction) conditions, in particular, temperature conditions, so that quantitative HFO-1123 can be produced, which is an economic advantage. Is big. Furthermore, by-products that can generate difluorocarbene (F ₂ C :) can be recycled and used as raw material components, which is useful as an industrial production method.

  Therefore, the production method of the present invention can significantly reduce the cost required for raw materials and production equipment, compared with the conventional production method using an expensive metal catalyst or highly explosive hydrogen, for example. It is advantageous. Furthermore, as mentioned above, since it is possible to suppress the formation of by-products that are difficult to be separated from HFO-1123 such as HFO-1132 (E), a known technique such as pressure distillation can be used without employing a special purification method. It is useful as an industrial production method in that high-purity HFO-1123 can be obtained by carrying out the purification separation used.

It is a figure which shows an example of the reaction apparatus used for the manufacturing method of this invention. It is a figure which shows an example of the reaction apparatus used for the manufacturing method of this invention.

Embodiments of the present invention will be described below.
The present invention provides a method for producing HFO-1123 by a synthesis reaction involving thermal decomposition using TFE and R31 as raw materials. And this manufacturing method
(A) mixing the TFE and the R31 in advance or separately supplying them to the reactor;
(B) supplying a heat medium to the reactor;
(C) In the reactor, with the temperature in the reactor controlled to 400 to 950 ° C., the TFE, the R31, and the heat medium are brought into contact with each other to generate the HFO-1123. Have.

The production method of the present invention may be a continuous production method or a batch production method. In the continuous production method, supply of TFE and R31, which are raw materials, to the reactor, supply of the heat medium to the reactor, contact between the raw material and the heat medium in the reactor, and a reaction including HFO-1123 Any removal of the mixture from the reactor is carried out continuously. In batch-type production, the supply of the raw material in the step (a) and the supply of the heat medium in the step (b) may be performed earlier or simultaneously. That is, when one of the raw material and the heat medium is supplied, even if the other is not supplied into the reactor, the component supplied later is retained during the retention of the previously supplied raw material or the heat medium. The raw material and the heat medium that are supplied may be in contact with each other for a predetermined time in a reactor in which the internal temperature is controlled within the specific temperature range.
The production method of the present invention is preferably a continuous method in terms of production efficiency. Hereinafter, although embodiment which applies the method of this invention to continuous manufacture is described, this invention is not limited to this. In addition, the process of taking out the reaction mixture containing HFO-1123 from the reactor is hereinafter referred to as process (d). Therefore, in the continuous production method, the step (a), the step (b), the step (c), and the step (d) are continuously performed.

<Synthesis reaction with TFE and R31>
The main reaction in the reactor in the production method of the present invention is shown in the following formula (1).

The raw materials TFE and R31 are difluorocarbene (F ₂ C :), which is an intermediate produced from TFE, and fluoromethyl radical, which is an intermediate produced from R31, by thermal decomposition and dechlorination reaction in the reactor. A reaction intermediate such as H ₂ FC ·) is produced. Then, in the mixture containing these reaction intermediates and unreacted raw material compounds, the reaction intermediates or the reaction intermediates and the raw material compounds are directly subjected to an addition reaction, or finally through one or more other intermediates. To HFO-1123. In the present invention, these thermal decomposition reaction to the formation reaction of HFO-1123 are referred to as a synthesis reaction involving thermal decomposition.

<Raw material>
The method for producing HFO-1123 of the present invention uses TFE and R31 as raw materials.
The molar ratio of the supply amount of R31 to the supply amount of TFE supplied to the reactor (hereinafter referred to as “molar ratio R31 / TFE”) is preferably in the range of 0.01 to 100, and in the range of 0.05 to 20. Is more preferable, and the range of 0.1 to 10 is particularly preferable. When the molar ratio R31 / TFE is 0.01 to 100, the conversion rate of the raw material, particularly the conversion rate of R31, is high, and HFO-1123 can be produced efficiently. Moreover, the ratio of HFO-1123 in the reaction mixture taken out from the reactor can be set to a certain level or more.
In the present invention in which the raw material and the heat medium are continuously circulated through the reactor to perform the reaction, the supply amount of each raw material and the heat medium indicates the supply amount per unit time.

As a raw material, in addition to these two components, a fluorine-containing compound (excluding TFE) that can be thermally decomposed in a reactor as necessary to generate F ₂ C :, for example, chlorodifluoromethane (R22 ), CTFE, hexafluoropropene (HFP), octafluorocyclobutane (RC318), hexafluoropropene oxide (HFPO), and the like. Further, by using a fluorine-containing compound that can be thermally decomposed in such a reactor to generate F ₂ C: as a raw material component, F ₂ C: is generated, reacts with R31, and finally HFO-1123. Is generated.

When a fluorine-containing compound that can be pyrolyzed in such a reactor to generate F ₂ C: is used as a raw material, a newly prepared fluorine-containing compound may be used, but it involves the above pyrolysis reaction. From the viewpoint of recycling, it is preferable to use one or more fluorine-containing compounds by-produced in the synthesis reaction, for example, one selected from HFP, RC318, and CTFE. By thermally decomposing in a reactor F _{2 C:} a fluorine-containing compound capable of generating a (excluding TFE.), "Other F _{2 C:} source compound" also referred to.

In the production method of the present invention, the reaction mixture containing HFO-1123 is taken out from the outlet of the reactor. The reaction mixture includes unreacted raw materials, reaction products, by-products and a heat medium. From the reaction mixture, the heat medium and the target product, HFO-1123, are separated, and by-products are further removed, and mainly composed of TFE and R31 as unreacted raw materials and other F ₂ C: source compounds. Is obtained. By supplying this mixture to the reactor together with fresh TFE and R31, it is possible to recycle the TFE, R31 and F ₂ C: source compounds, which is economically advantageous.

[Step (a)]
Step (a) in the production method of the present invention is a step in which TFE and R31 are mixed in advance or separately supplied to the reactor.
In step (a), each raw material may be introduced into the reactor at room temperature, but in order to improve the reactivity in the reactor, the temperature at the time of introduction into the reactor is adjusted by heating or the like. May be. However, since TFE and other F ₂ C: source compounds and R31 have different temperature ranges suitable for improving the reactivity, it is preferable to perform temperature adjustment separately.

The temperature of TFE supplied to the reactor is preferably 0 to 600 ° C., more preferably 25 to 600 ° C., and most preferably 100 to 500 ° C. from the viewpoint of further increasing the reactivity.
When other F ₂ C: source compounds are used, TFE and the other F ₂ C: source compounds have a certain degree of reactivity, but they are independently used in the reactor from the viewpoint of setting the temperature to be difficult to carbonize. It is preferable to supply, and the temperature is preferably 0 to 600 ° C, more preferably 25 to 600 ° C, and most preferably 100 to 500 ° C.

The temperature of R31 supplied to the reactor is preferably 0 to 950 ° C. from the viewpoint of reactivity. From the viewpoint of increasing the reactivity, 25 to 900 ° C is preferable, and 100 to 800 ° C is more preferable.
However, the temperature of each raw material component supplied to the reactor is set to be equal to or lower than the temperature in the reactor in the step (c) described later.

TFE and R31, as well as other F ₂ C used as necessary, may be supplied separately to the reactor for each raw material, or may be supplied after mixing each raw material. . When the raw materials are mixed and then supplied, the raw materials are preferably divided into groups. For example, TFE and other F ₂ C used as necessary may be divided into the source compound and the others, and each raw material may be mixed in each group and supplied separately to the reactor, or all raw materials may be mixed Then, it may be supplied. In consideration of the difference in the above temperature conditions, TFE and other F ₂ C: source compounds used as necessary are mixed, adjusted to the above preferable temperature conditions, and supplied to the reactor. It is preferable to adjust to the above preferable temperature conditions and supply to the reactor.

In addition, when each raw material of TFE and R31 and other F ₂ C: source compounds used as necessary is mixed in advance and then supplied to the reactor, the reaction and decomposition proceed before the reactor. From the viewpoint of preventing this, the temperature during introduction into the reactor is preferably 600 ° C. or lower, more preferably 500 ° C. or lower.

[Step (b)]
Step (b) in the production method of the present invention is a step of supplying a heat medium to the reactor.

<Heat medium>
In the step (b) of the present invention, the heat medium is supplied to the reactor so as to be in contact with the raw material for a certain time in the reactor. The heat medium is a medium that does not undergo thermal decomposition at the temperature in the reactor, and is specifically preferably a medium that does not undergo thermal decomposition at the reaction temperature (100 to 950 ° C.). Examples of the heat medium include water vapor, nitrogen, carbon dioxide, and the like. The heat medium is preferably at least one selected from the group consisting of water vapor, nitrogen and carbon dioxide, and more preferably a mixture containing 50% by volume or more of water vapor, with the balance being nitrogen and / or carbon dioxide. In order to remove hydrogen chloride generated by the reaction of each raw material by contact with the heat medium as hydrochloric acid, the content ratio of water vapor in the heat medium is preferably 50% by volume or more, more preferably 100% by volume (that is, only water vapor). .

  The supply amount of the heat medium is preferably 20 to 98% by volume, and more preferably 50 to 95% by volume with respect to the total amount of the heat medium and the raw material. When the supply amount of the heat medium is 20% by volume or more, HFO-1123 can be efficiently produced by advancing the reaction by the contact between the raw material and the heat medium while suppressing the formation of high boilers and carbonization of the raw material. Further, when the ratio is 98% by volume or less, productivity is not significantly reduced, and an industrially realistic process is obtained. Further, the temperature of the heat medium supplied to the reactor is preferably 100 to 950 ° C. from the viewpoint of further improving the thermal decomposition and the reactivity of the raw material components. From the viewpoint of further increasing the reactivity of the raw material components, the temperature of the heat medium supplied to the reactor is more preferably 400 to 950 ° C, and most preferably 500 to 950 ° C.

<Reaction conditions>

The temperature in the reactor in the step (c) is a temperature equal to or higher than the temperature of each raw material component supplied to the reactor, that is, R31, TFE and other F ₂ C: source compound used as necessary, and 400-950 degreeC. As for the temperature in the reactor in a process (c), 500-950 degreeC is more preferable, and 600-950 degreeC is the most preferable. When the temperature in the reactor is 400 to 950 ° C., the reaction rate of the synthesis reaction involving thermal decomposition represented by the above formula (1) is increased, and the production of by-products, particularly HFO-1132 (E), is suppressed. Thus, HFO-1123 can be obtained efficiently.

  The temperature in the reactor can be controlled by adjusting the temperature and pressure of the heat medium supplied to the reactor. Further, the inside of the reactor can be supplementarily heated with an electric heater or the like so that the temperature in the reactor falls within a particularly preferable temperature range (600 to 950 ° C.).

  The pressure in the reactor is preferably 0 to 2 MPa in gauge pressure, and more preferably in the range of 0 to 0.5 MPa.

  The contact time of the heat medium and the raw material in the reactor is preferably 0.01 to 10 seconds, and more preferably 0.01 to 3.0 seconds. When the contact time is 0.01 to 10 seconds, the synthesis reaction of HFO-1123 can sufficiently proceed. The contact time between the heat medium and the raw material corresponds to the residence time of the raw material in the reactor, and can be controlled by adjusting the supply amount (flow rate) of the raw material to the reactor.

  The shape of the reactor is not particularly limited as long as it can withstand the temperature and pressure in the reactor described later, and examples thereof include a cylindrical vertical reactor. Examples of the material of the reactor include glass, iron, nickel, or an alloy mainly composed of iron and nickel.

<Reactor>
In the present invention, an example of a reaction apparatus used for production of HFO-1123 is shown in FIGS.
The reaction apparatus 20 has a reactor 1 provided with heating means such as an electric heater. Connected to the reactor 1 are a supply line 2 for R31 as a first raw material component, a supply line 3 for TFE as a second raw material component, and a supply line 4 for steam as a heat medium as shown below. Has been. In addition, installation of the heating means in the reactor 1 is not essential.

  The R31 supply line 2 and the TFE supply line 3 are provided with preheaters (preheaters) 2a and 3a each equipped with an electric heater or the like, and after each raw material component to be supplied is preheated to a predetermined temperature. It is supplied to the reactor 1. The steam supply line 4 is provided with a heated steam generator 4a, and the temperature and pressure of the steam supplied are adjusted.

These supply lines 2, 3, and 4 may be separately connected to the reactor 1, but some or all of the supply lines may be connected before the reactor 1 and connected to the reactor. Good. For example, as shown in FIG. 1, the raw material mixture in which all raw material components are mixed is reacted from the raw material mixing supply line 5 by connecting the supply lines 2 and 3 after passing through the respective preheaters 2 a and 3 a. The steam supplied to the reactor 1 may be supplied from the steam supply line 4 to the reactor 1 separately from the raw material mixing supply line 5.
Moreover, like the reaction apparatus 20 shown in FIG. 2, it can also comprise so that TFE, R31, and water vapor | steam may be separately supplied to the reactor 1, and these may be mixed integrally in the vicinity of the inlet_port | entrance of the reactor 1. FIG.

  An outlet line 7 provided with a cooling means 6 such as a water cooler is connected to the outlet of the reactor 1. The outlet line 7 is further provided with a water vapor and acidic liquid recovery tank 8, an alkali cleaning device 9, and a dehydration tower 10 in this order. Then, after dehydration by the dehydration tower 10, each component of the obtained gas is analyzed and quantified by an analyzer such as gas chromatography (GC). In addition, the reaction mixture containing HFO-1123 is taken out from the reactor 1, and the gas obtained by removing acidic substances such as hydrogen chloride, water vapor, water, etc. by the treatment after the outlet line 7 as described above, Hereinafter, it is called outlet gas.

<Outlet gas component>
The outlet gas contains HFO-1123, which is the target product. Examples of compounds other than HFO-1123 and unreacted raw material components (TFE, R31) contained in the outlet gas include HFO-1132 (E / Z), 1,1-difluoroethylene (VdF), CTFE, 1-chloro- 2,2-difluoroethylene (HCFO-1122), E / Z-1,2-dichlorofluoroethylene (HCFO-1122a (E / Z)), 1,1,2-trifluoroethane (HFC-143), methane E / Z-1-chloro-2-fluoroethylene (HCFO-1131 (E / Z)), fluoroethylene (HFO-1141), 3,3-difluoropropene (HFO-1252zf), 3,3,3- Trifluoropropene (HFO-1243zf), 2,3,3,3-tetrafluoropropene (HFO-1234yf), E / Z-1, , 3,3-tetrafluoropropene (HFO-1234ze (E / Z)), HFP, E / Z-1,2,3,3,3-pentafluoropropene (HFO-1225ye (E / Z)), 1 , 1,3,3,3-pentafluoropropene (HFO-1225zc), HFC-125, HFC-134, HFC-134a, 1,1,1-trifluoroethane (HFC-143a), 1-chloro-1 , 2,2,2-tetrafluoroethane (HCFC-124), 1-chloro-1,1,2,2-tetrafluoroethane (HCFC-124a), 1,1,1,2,2,3,3 -Heptafluoropropane (HFC-227ca), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,3,3,3-hexafluoropro (HFC-236fa), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), dichlorodifluoromethane (CFC-12), HFC-32, trifluoromethane (HFC-23), fluoro Examples include methane (HFC-41), chloromethane, RC318, and the like. In the above, E / Z means a mixture of E body and Z body.

Among these components, compounds having a methyl group (—CH ₃ ), a methylene group (—CH ₂ —, ═CH ₂ ), or a methine group (≡CH, —CH═), specifically, methane, VdF HFC-143a and the like, and compounds having a moiety in which one fluorine atom and one hydrogen atom are bonded to one carbon (-CFH-, = CFH), specifically, HFO-1132, HFC-143, HFO -1311, HFO-1141, HFO-1123, and HFO-1225 (where HFO-1225 is a generic term for HFO-1225ye and HFO-1225zc) and the like are compounds derived from R31 of the raw material component. Further, compounds having a moiety in which two or more fluorine atoms are bonded to one carbon, specifically, HFP, CTFE, HFO-1123, HFO-1225, RC318, VdF, etc. are all derived from TFE as a raw material component. It is a compound. HFO-1123 is a compound derived from RFE as well as a compound derived from TFE.

  The above components other than HFO-1123 contained in the outlet gas can be removed to a desired extent by known means such as distillation. According to the production method of the present invention, since a by-product having a boiling point close to that of HFO-1123 such as HFO-1132 (E) can be suppressed, a general distillation can be performed without using a special purification method or apparatus. By using an apparatus or the like, HFO-1123 purified to a high purity can be produced.

The separated TFE and R31 can be recycled as a part of the raw material components. HFP, CTFE and RC318 are F ₂ C: source compounds and can be recycled as part of the raw material components. The obtained VdF, TFE, HFP, CTFE, etc. are PVdF (VdF polymer), PTFE (TFE polymer), FEP (TFE-HFP copolymer), VdF-HFP copolymer, It can be used as a raw material for fluororesins such as PCTFE (CTFE polymer) and ECTFE (ethylene-CTFE copolymer).

  Furthermore, in this invention, since the boiling point is near, the production | generation of the by-product which is very hard to isolate | separate can be suppressed and HFO-1123 with high purity can be obtained. That is, among the by-products, HFO-1132 (E) has a boiling point of −51 ° C. and very close to that of HFO-1123 (−54 ° C.). Although it is difficult, in the present invention, R31 and TFE are used as raw materials, and the temperature in the synthesis reaction involving thermal decomposition of these raw materials is controlled within a specific range. The ratio of the production amount of HFO-1132 (E) to the production amount of HFO-1123 can be greatly reduced by controlling the temperature of the above to the specific range, and a higher purity HFO-1123 is obtained. Can do.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 4 are examples, and example 5 is a comparative example.

(Example 1)
Using the reaction apparatus shown in FIG. 1, crude HFO-1123 was obtained as shown below from a raw material gas composed of TFE and R31.

  R31 was continuously introduced into the stainless steel tube preheater 2a in the electric furnace set at a furnace temperature of 300 ° C., and R31 was heated to 300 ° C. Further, TFE was continuously introduced into a preheater 3a made of a stainless steel tube in an electric furnace set at a furnace temperature of 300 ° C., and the TFE was heated to 300 ° C.

  Steam (steam) heated by a heated steam generator 4a, which is an electric furnace set to an in-furnace temperature of 750 ° C., was supplied to the reactor 1 controlled at 0.04 MPa and an internal temperature of 750 ° C. Furthermore, the raw material gas components (R31 and TFE) that have been preheated and adjusted to the above temperature, the supply amount of the raw material gas components is a molar ratio R31 / TFE = 0.5, and the supply of water vapor to the entire gas supply amount The ratio (a ratio indicated by a volume ratio of water vapor / (R31 + TFE + water vapor)) was supplied to the reactor 1 so as to be 90% by volume. The reactor 1 was controlled to have an internal pressure (gauge pressure) of 0.04 MPa and an internal temperature of 750 ° C. Hereinafter, all the pressures are assumed to be gauge pressures.

  In this way, the flow rate of the source gas (amount supplied per unit time) was controlled so that the residence time of the source gas in the reactor was 0.2 seconds, and the gas of the reaction mixture was taken out from the outlet of the reactor. The actually measured value of the reactor internal temperature was 750 ° C., and the actually measured value of the reactor internal pressure was 0.04 MPa. In addition, the gas of the reaction mixture taken out from the outlet of the reactor includes unreacted source gas in addition to the gas generated or by-produced by the reaction.

Next, the gas of the reaction mixture taken out from the outlet of the reactor is cooled to 100 ° C. or lower, and after performing steam and acidic liquid recovery and alkali washing in order, dehydration treatment is performed, the obtained outlet gas is subjected to gas chromatography. Analysis was performed to calculate the molar composition of the gas component contained in the outlet gas. These results are shown in Table 1 together with the reaction conditions.
In addition, the preheating temperature of R31 and TFE is a set temperature in each electric furnace for preheating, and the water vapor temperature is a set temperature in an electric furnace for water vapor heating. The water vapor pressure is a set pressure.

  The molar ratio of TFE, R31 and HFO-1123 in the outlet gas was calculated based on the molar composition of the outlet gas obtained by gas chromatography analysis. Furthermore, the conversion rate (reaction rate) of R31, the selectivity of each component derived from R31, the conversion rate of TFE (reaction rate), and HFO-1123 / HFO-1132 (E) (molar ratio) were determined. These results are shown in the lower column of Table 1.

The above values mean the following respectively.
(Yield of each component derived from R31)
R31-derived component (methyl group (—CH ₃ ), methylene group (—CH ₂ —, ═CH ₂ ) or methine group (≡CH, —CH═) in the outlet gas, one fluorine atom and hydrogen It means the proportion (mol%) of each compound other than R31 in the compound having a moiety (—CFH—, ═CFH) in which one atom is bonded to one carbon.
(R31 conversion rate (reaction rate))
Among the components derived from R31 in the outlet gas, when the proportion of R31 (R31 yield) is X%, (100-X)% is referred to as the conversion rate (reaction rate) of R31. It means the ratio (mol%) of reacted R31.
(Selectivity of each component derived from R31)
Of the reacted R31, the percentage converted to each component other than R31 is the percentage. The selectivity of each component is determined by “yield of each component derived from R31” / “conversion rate (reaction rate) of R31”.

(TFE conversion rate (reaction rate))
Of the TFE-derived components (compounds having two or more fluorine atoms bonded to one carbon) in the outlet gas, when the proportion of TFE (TFE yield) is X%, (100-X) % Is referred to as TFE conversion (reaction rate). It means the ratio (mol%) of reacted TFE.

(HFO-1123 / HFO-1132 (E))
It is the ratio of the abundance ratio of HFO-1123 to the abundance ratio of HFO-1132 (E) in the outlet gas. It is obtained by “the outlet gas molar composition of HFO-1123” / “the outlet gas molar composition of HFO-1132 (E)”. It represents how much (molar ratio) HFO-1123 is present in the outlet gas with respect to HFO-1132 (E).

[Example 2]
The reaction was carried out under the same conditions as in Example 1 except that the set temperature of the electric furnace for heating the steam was 800 ° C. and the internal temperature of the reactor was controlled to 800 ° C. Subsequently, the gas of the reaction mixture taken out from the outlet of the reactor was treated in the same manner as in Example 1, and then the obtained outlet gas was analyzed in the same manner as in Example 1. The results are shown in Table 1 together with the reaction conditions.

[Example 3]
The reaction was carried out under the same conditions as in Example 1 except that the set temperature of the electric furnace for heating the steam was 850 ° C. and the internal temperature of the reactor was controlled at 850 ° C. Subsequently, the gas of the reaction mixture taken out from the outlet of the reactor was treated in the same manner as in Example 1, and then the obtained outlet gas was analyzed in the same manner as in Example 1. The results are shown in Table 1 together with the reaction conditions.

[Example 4]
The temperature of the electric furnace for heating the steam is set to 650 ° C., the internal temperature of the reactor is controlled to 650 ° C., and the flow rate of the raw material gas is set so that the residence time of the raw material gas in the reactor is 0.61 seconds. The reaction was carried out under the same conditions as in Example 1 except that the control was performed. Subsequently, the gas of the reaction mixture taken out from the outlet of the reactor was treated in the same manner as in Example 1, and then the obtained outlet gas was analyzed in the same manner as in Example 1. The results are shown in Table 1 together with the reaction conditions.

[Example 5]
The reaction was carried out under the same conditions as in Example 1 except that the set temperature of the electric furnace for heating the steam was 980 ° C. and the internal temperature of the reactor was controlled at 980 ° C. Subsequently, the gas of the reaction mixture taken out from the outlet of the reactor was treated in the same manner as in Example 1, and then the obtained outlet gas was analyzed in the same manner as in Example 1. The results are shown in Table 1 together with the reaction conditions.

According to the production method of the present invention, industrially useful HFO-1123 can be efficiently produced with high purity by suppressing the formation of by-products that are difficult to be separated from HFO-1123 such as HFO-1132 (E). A method of manufacturing can be provided.
It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2013-136611 filed on June 28, 2013 is cited here as the disclosure of the specification of the present invention. Incorporated.

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... R31 supply line, 3 ... TFE supply line, 4 ... Steam supply line, 2a, 3a ... Preheater (preheater), 4a ... Heated steam generator, 5 ... Raw material mixing supply line, DESCRIPTION OF SYMBOLS 6 ... Cooling means, 7 ... Outlet line, 8 ... Steam | vapor and acidic liquid collection tank, 9 ... Alkaline washing | cleaning apparatus, 10 ... Dehydration tower, 20 ... Reaction apparatus.

Claims (9)

A method for producing trifluoroethylene from tetrafluoroethylene and chlorofluoromethane,
(A) supplying the tetrafluoroethylene and the chlorofluoromethane to the reactor by mixing them in advance or separately;
(B) supplying a heat medium to the reactor;
(C) In the reactor, the trifluoroethylene is produced by bringing the tetrafluoroethylene, the chlorofluoromethane, and the heat medium into contact with each other while the temperature in the reactor is controlled to 400 to 950 ° C. A process of
A process for producing trifluoroethylene, comprising:   The manufacturing method of the trifluoroethylene of Claim 1 whose supply_amount | feed_rate of the said chlorofluoromethane is 0.01-100 mol with respect to 1 mol of the said tetrafluoroethylene.   The manufacturing method of the trifluoroethylene of Claim 1 or 2 whose temperature of the said chlorofluoromethane supplied to the said reactor is 0-950 degreeC.   The manufacturing method of the trifluoroethylene of any one of Claims 1-3 whose temperature of the said tetrafluoroethylene supplied to the said reactor is 0-600 degreeC.   The manufacturing method of the trifluoroethylene of any one of Claims 1-4 whose temperature of the said heat medium supplied to the said reactor is 100-950 degreeC.   The method for producing trifluoroethylene according to any one of claims 1 to 5, wherein the heat medium comprises at least one selected from the group consisting of water vapor, nitrogen and carbon dioxide.   The method for producing trifluoroethylene according to any one of claims 1 to 6, wherein a supply amount of the heat medium is 20 to 98% by volume in a total gas supplied to the reactor.   The manufacturing method of the trifluoroethylene of any one of Claims 1-7 whose contact time in a process (c) is 0.01 to 10 second.   The method for producing trifluoroethylene according to any one of claims 1 to 8, wherein the process from the supply of the raw material to the reactor to the removal of the reaction mixture from the reactor is continuously performed.

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