JP2015117188A - Method for producing trifluoroethylene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economically advantageous method for efficiently producing high purity trifluoroethylene by using easily available raw materials without using a catalyst by a synthetic reaction accompanied by thermal decomposition.SOLUTION: There is provided a method for producing trifluoroethylene from tetrafluoroethylene and hydrogen by a synthetic reaction accompanied by thermal decomposition, the method comprising: (a) a step of mixing tetrafluoroethylene and hydrogen in advance to feed into a reactor or feeding tetrafluoroethylene and hydrogen separately into a rector; (b) a step of feeding a heating medium into the reactor; and (c) a step of bringing the tetrafluoroethylene and the hydrogen into contact with each other in the reactor in a state of controlling the temperature inside the reactor at 400 to 950°C to generate the trifluoroethylene.

Description

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

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).
In the present specification, for halogenated hydrocarbons, as described above, the abbreviations of the compounds are shown in parentheses after the compound names. Moreover, the abbreviation is used instead of the compound name as necessary.

  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 (CFC-113) with hydrogen in the presence of a catalyst such as palladium (see, for example, Patent Document 3). ) Etc. are known.

  However, in the production method using the catalyst process described in Patent Documents 1 to 3, catalyst preparation, catalyst replacement in the catalyst filling reactor accompanying catalyst deactivation, catalyst disposal or reactivation, catalyst filling with polymer by-products There were many economical disadvantages such as the possibility of clogging of the reactor and a long reaction time, and high purity HFO-1123 could not be obtained efficiently.

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

  As a result of repeated studies by the present inventors, since the transition metal catalyst is used in any of the methods disclosed in Patent Document 1 and Patent Document 3, hydrogen reduction proceeds excessively, resulting in Z-1,2-difluoro. It was found that ethylene (HFO-1132 (Z)) was produced. Moreover, since this HFO-1132 (Z) has a boiling point very close to HFO-1123, it turned out that the distillation refinement | purification separation of both is difficult.

  The present invention has been made from the above viewpoint. Byproducts which are difficult to be separated from HFO-1123 by distillation from HFO-1123 industrially useful in a synthesis reaction involving thermal decomposition without using a catalyst, particularly, An object of the present invention is to provide an economically advantageous method for efficiently producing high purity by suppressing the formation of HFO-1132 (Z).

The present invention is a method for producing HFO-1123 from tetrafluoroethylene (TFE) and hydrogen,
(A) mixing the TFE and the hydrogen in advance or separately supplying them to the reactor;
(B) supplying a heat medium to the reactor;
(C) In the reactor, the TFE, the hydrogen, and the heat medium are brought into contact with each other to generate HFO-1123, and the temperature in the reactor in step (c) is set to 400 to 950. Provided is a method for producing HFO-1123, characterized by adjusting the temperature to ° C.

  According to the manufacturing method of the present invention, a global warming potential (GWP) is obtained by a synthesis reaction involving thermal decomposition controlled to a specific temperature without using a catalyst, using TFE and hydrogen that are easy to procure as raw materials. HFO-1123 that is small and industrially useful as a new refrigerant can be efficiently produced.

  Moreover, according to the manufacturing method of this invention, since the boiling point is near, the production | generation of the by-product which is difficult to isolate | separate can be suppressed and HFO-1123 with high purity can be obtained. That is, among the by-products, HFO-1132 (Z) has a boiling point of −51 ° C. and very close to that of HFO-1123 (−54 ° C.). Although it is difficult, according to the production method of the present invention, it is possible to produce high-purity HFO-1123 by suppressing the formation of by-products that are difficult to be separated from HFO-1123 such as HFO-1132 (Z). it can.

Furthermore, according to the production method of the present invention, the use of a heat medium makes it easy to control production (reaction) conditions, in particular, temperature conditions, so that HFO-1123 can be produced stably and economically. The major merit is great. Furthermore, a by-product that can generate difluorocarbene (F ₂ C :), which will be described later, can be recycled and used as a raw material, which is useful as an industrial production method.

  Therefore, the production method of the present invention is economically advantageous because the cost required for the raw materials and the production equipment can be greatly reduced as compared with, for example, a conventional production method using an expensive metal catalyst. Furthermore, as mentioned above, since it is possible to suppress the formation of by-products that are difficult to separate from HFO-1123 such as HFO-1132 (Z), 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 another 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 hydrogen as raw materials. And this manufacturing method
(A) mixing the TFE and the hydrogen in advance or supplying them separately to the reactor (step (a));
(B) supplying a heat medium to the reactor (step (b));
(C) In the reactor, the temperature in the reactor is adjusted to 400 to 950 ° C., and the TFE, the hydrogen, and the heat medium are brought into contact with each other to generate HFO-1123 (step (c)) ).
Furthermore, the present invention provides
After the step (c), the method may include a step (d) of removing a reaction mixture containing HFO-1123 produced in the reactor from the reactor. In addition, the process of taking out HFO-1123 from a reactor is called (d) process in the following description.
Hereinafter, TFE and hydrogen are also referred to as “raw materials”. As will be described later, as the “raw material”, other fluorine-containing compounds may be used together with TFE and hydrogen.

The production method of the present invention may be a continuous production method or a batch production method. In a continuous production method, a raw material, that is, supply of TFE and hydrogen to a reactor and supply of a heat medium to the reactor, contact of the raw material with the heat medium in the reactor, and a reaction mixture containing HFO-1123 Removal from the reactor is carried out continuously.
In batch-type production, either the supply of the raw material in the step (a) or the supply of the heat medium in the step (b) may be performed first or simultaneously. That is, when either one of the raw material and the heat medium is supplied, even if the other is not supplied in the reactor, the component supplied later in the reactor to the previously supplied raw material or heat medium The raw material and the heat medium may be brought into 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, an embodiment in which the method of the present invention is applied to continuous production will be described. In the continuous production method, the steps (a), (b), (c) and (d) are continuously performed in this order.

<Synthesis reaction with TFE and hydrogen>
In the production method of the present invention, the main reaction that is considered to occur in the reactor is represented by the following formula (1).

That is, TFE as a raw material generates trifluoroethenyl radicals by heating in a reactor, and H ₂ (hydrogen) as a raw material or hydrogen radicals (H.) generated from H ₂ are combined to form HFO- 1123 is considered to generate. In the present invention, such a thermal decomposition reaction to a formation reaction of HFO-1123 is referred to as a synthesis reaction involving thermal decomposition.

<Raw material>
In the method for producing HFO-1123 of the present invention, TFE and hydrogen are used as raw materials.
The molar ratio of the hydrogen supply amount to the TFE supply amount supplied to the reactor (hereinafter referred to as hydrogen / TFE “molar ratio”) 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 hydrogen / TFE “molar ratio” is 0.01 to 100, the conversion rate of the raw material, particularly the conversion rate of hydrogen is high, and HFO-1123 can be produced efficiently. Moreover, the ratio of HFO-1123 in the reaction product taken out from the reactor can be set to a certain level or more.
In the embodiment of the present invention in which the reaction is performed by continuously circulating the raw material and the heat medium in the reactor, 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 to generate difluorocarbene (F ₂ C :), such as chlorodifluoromethane (R22). ), Chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), octafluorocyclobutane (RC318), hexafluoropropene oxide (HFPO) and the like can be used as necessary. As a raw material, such reactor is thermally decomposed in F _{2 C:} a further possible to use a fluorine-containing compound and may occur, F 2 _C: from TFE is generated, the TFE reacts with hydrogen Last Thus, HFO-1123 is generated.

When a fluorine-containing compound capable of generating F ₂ C: by pyrolysis in such a reactor is used as a raw material, a newly prepared fluorine-containing compound may be used, but the above-described TFE and hydrogen From the viewpoint of recycling, it is preferable to use one or more fluorine-containing compounds that are by-produced in a synthesis reaction involving a thermal decomposition reaction by, for example, HFP, RC318, and the like. 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, a heat medium, and the like. From the reaction mixture, the heat medium and the target product, HFO-1123, are separated, and further, by-products are removed, and mainly composed of TFE and hydrogen as unreacted raw materials and other F ₂ C: source compounds. Is obtained. Feeding this mixture to the reactor along with fresh TFE and hydrogen is economically advantageous, as it allows recycling of TFE and other F ₂ C: source compounds.

[Step (a)]
In the production method of the present invention, the step (a) of mixing TFE and hydrogen in advance or supplying them separately to the reactor is referred to as the step (a).
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 hydrogen have different temperature ranges suitable for improving reactivity, it is preferable to perform temperature adjustment separately. Even when other F ₂ C: source compounds are used, it is preferable to adjust the temperature 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.

The temperature of hydrogen 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 supplied to the reactor is set to be equal to or lower than the temperature in the reactor in the step (c) described later.
When using other F ₂ C: source compounds, TFE and the other F ₂ C: source compounds have high reactivity to some extent, but from the viewpoint of making the temperature difficult to carbonize, the reactors are independent of each other. It is preferable to supply to. The temperature of the other F ₂ C: source compound supplied to the reactor is preferably 0 to 600 ° C, more preferably 25 to 600 ° C, and most preferably 100 to 500 ° C.

The feeds of TFE and hydrogen as raw materials, and other F ₂ C: source compounds used as necessary may be supplied separately or after each raw material is mixed. . 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: source compounds used as necessary may be divided into other groups, and each raw material may be mixed in each group and supplied separately to the reactor. You may supply after mixing. In consideration of the difference in the temperature conditions, TFE and other F ₂ C: source compounds used as necessary are mixed, adjusted to the preferred temperature and supplied to the reactor, and separately from this, hydrogen is added to the above It is preferable to adjust to a preferable temperature and supply it to the reactor.

In addition, when each raw material of TFE, hydrogen, 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 at the time of introduction into the reactor is preferably from 0 to 600 ° C, more preferably from 0 to 500 ° C.

[Step (b)]
In the production method of the present invention, the step of supplying the heat medium to the reactor is referred to as the step (b).

<Heat medium>
In the step (b), the heat medium is supplied to the reactor so as to come into 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 specifically, is preferably a medium that does not undergo thermal decomposition at the reaction temperature (400 to 950 ° C.). Examples of the heat medium include gases such as water vapor, nitrogen, and carbon dioxide, and may be a mixture of two or more gases. When the heat medium contains 50% by volume or more of water vapor and the other part contains other gas, the gas is preferably nitrogen and / or carbon dioxide. In order to conduct a larger amount of heat to the raw material, the content ratio of water vapor in the heat medium is preferably 50% by volume or more, and more preferably 100% by volume (water vapor only).

  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 increasing the thermal decomposition and reactivity of the raw materials. From the viewpoint of further increasing the reactivity of the raw material, the temperature of the heat medium supplied to the reactor is more preferably 400 to 950 ° C, and most preferably 500 to 950 ° C.

[(C) Step]
In the production method of the present invention, the step of bringing the heating medium into contact with TFE and hydrogen in the reactor to produce HFO-1123 is referred to as step (c).

<Reaction conditions>
The temperature in the reactor in the step (c) is in the range of 400 to 950 ° C., and each raw material to be supplied to the reactor, that is, hydrogen, TFE, and other F ₂ C: sources used as necessary The temperature is higher than the temperature of the compound. (C) As for the temperature in the reactor in a process, 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 (Z), 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 by an electric heater, a microwave generator or the like so that the temperature in the reactor is in 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 proceeds sufficiently. 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, 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 this invention, the example of the reaction apparatus used for manufacture of HFO-1123 is shown in FIG. 1 and FIG.
The reaction apparatus 20 has a reactor 1 provided with heating means such as an electric heater. A hydrogen supply line 2 as a first raw material, a TFE supply line 3 as a second raw material, and a steam supply line 4 as a heat medium are connected to the reactor 1 as shown below. Yes. In addition, installation of the heating means in the reactor 1 is not essential.

  The hydrogen 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 react after each supplied raw material is preheated to a predetermined temperature. Supplied to the vessel 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 connected to the reactor 1 separately, 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, by connecting supply lines 2 and 3 after passing through respective preheaters 2a and 3a, a raw material mixture in which all raw materials are mixed is supplied from a raw material mixing supply line 5 to a reactor. 1, the steam 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, hydrogen, and water vapor | steam may be separately supplied to the reactor 1, and these may be mixed integrally in the entrance vicinity 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. After dehydration by the dehydration tower 10, 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>
The outlet gas contains HFO-1123, which is the target product. Examples of compounds other than HFO-1123 and unreacted raw materials (TFE and hydrogen) contained in the outlet gas include HFO-1132 (E / Z), 1,1-difluoroethylene (VdF), 1,1,2-trimethyl Fluoroethane (HFC-143), fluoroethylene (HFO-1141), 3,3-difluoropropene (HFO-1252zf), 3,3,3-trifluoropropene (HFO-1243zf), 2,3,3,3 -Tetrafluoropropene (HFO-1234yf), E / Z-1,3,3,3-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), HF -125, HFC-134, HFC-134a, 1,1,1-trifluoroethane (HFC-143a), 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), 1 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2 , 3,3-hexafluoropropane (HFC-236ea), HFC-32, trifluoromethane (HFC-23), fluoromethane (HFC-41), RC318 and the like. In the above, E / Z means a mixture of E body and Z body.

  Compounds having a moiety in which two or more fluorine atoms are bonded to one carbon, specifically, HFP, HFO-1123, HFO-1225, RC318, VdF, and the like are all compounds derived from TFE as a raw material.

  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 the production of by-products having close boiling points can be suppressed, HFO-1123 purified to a high purity by a general distillation apparatus or the like without using a special purification method or apparatus can be obtained. Can be manufactured.

The separated TFE can be recycled as part of the raw material. HFP and RC318 are F ₂ C: source compounds and can be recycled as part of the raw material. In addition, VdF, TFE, HFP, etc. obtained are fluorine, such as PVdF (VdF polymer), PTFE (TFE polymer), FEP (TFE-HFP copolymer), VdF-HFP copolymer, if necessary. It can be used as a raw material for resins.

  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 (Z) 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, hydrogen 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. By controlling the temperature of the above to the above specific range, the ratio of the production amount of HFO-1132 (Z) to the production amount of HFO-1123 can be greatly reduced, and HFO-1123 with higher purity can be 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.

(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 hydrogen.

  Hydrogen was continuously introduced into a preheater 2a of a stainless steel tube in an electric furnace set to a furnace temperature of 300 ° C, and the hydrogen was heated to 300 ° C (preheated). 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 a furnace temperature of 750 ° C., was supplied to the reactor 1 controlled to an internal temperature (gauge pressure) of 0.04 MPa and an internal temperature of 750 ° C. . Hereinafter, all the pressures are assumed to be gauge pressures. Further, the raw material gas (hydrogen and TFE) that has been preheated and adjusted to the above temperature is supplied with water vapor to the entire gas supply amount with the supply amount of the raw material gas being hydrogen / TFE [molar ratio] = 1.0. It was supplied to the reactor 1 so that the ratio (ratio indicated by the volume ratio of water vapor / (hydrogen + TFE + water vapor)) was 90% by volume.

  Thus, 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 0.29 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 water vapor and acidic liquid recovery and alkali washing in order, dehydration treatment is performed, and the obtained outlet gas is subjected to gas chromatography. Analysis was performed to calculate the molar composition of the gas contained in the outlet gas. These results are shown in Table 1 together with the reaction conditions.

  The molar ratio of TFE, HFO-1123, and R318 in the outlet gas was calculated based on the molar composition of the outlet gas obtained by analysis by gas chromatography. Furthermore, the yield of each component derived from TFE and the conversion rate (reaction rate) of TFE were determined, and the selectivity of each component derived from TFE was calculated. Furthermore, HFO-1123 / HFO-1132 (Z) (molar ratio) was 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 TFE)
It means the proportion (mol%) of each compound other than TFE among the TFE-derived components in the outlet gas. Here, the TFE-derived component includes a compound having a portion in which two or more fluorine atoms are bonded to one carbon, and a portion in which one fluorine atom and one hydrogen atom are bonded to one carbon (-CFH-, = CFH For example, TFE, HFO-1123, R318 and the like.

(TFE conversion rate (reaction rate))
Among the TFE-derived components 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.

(Selectivity of each component derived from TFE)
Of the reacted TFE, the percentage converted to each component other than TFE is the percentage of each. The selectivity of each component is determined by “yield of each component derived from TFE” / “conversion rate of TFE (reaction rate)”.

(HFO-1123 / HFO-1132 (Z))
It is the ratio of the abundance ratio of HFO-1123 to the abundance ratio of HFO-1132 (Z) in the outlet gas. It is calculated | required by "the exit gas molar composition of HFO-1123" / "the exit gas molar composition of HFO-1132 (Z)." It represents how much (molar ratio) HFO-1123 is present in the outlet gas with respect to HFO-1132 (Z).

[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 950 ° C. and the internal temperature of the reactor was controlled at 950 ° 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 (Z). A method of manufacturing can be provided.

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Hydrogen 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 and acidic liquid recovery tank, 9 ... Alkaline washing apparatus, 10 ... Dehydration tower, 20 ... Reactor.

Claims (9)

A process for producing trifluoroethylene from tetrafluoroethylene and hydrogen, comprising:
(A) a step of previously mixing the tetrafluoroethylene and the hydrogen or supplying them separately to the reactor (step (a));
(B) supplying a heat medium to the reactor (step (b));
(C) In the reactor, the temperature in the reactor is adjusted to 400 to 950 ° C., and the tetrafluoroethylene, the hydrogen, and the heat medium are brought into contact with each other to produce trifluoroethylene ((c ) Step) and a process for producing trifluoroethylene, comprising:   The method for producing trifluoroethylene according to claim 1, wherein the supply amount of hydrogen is 0.01 to 100 mol with respect to 1 mol of the tetrafluoroethylene supply amount.   The manufacturing method of the trifluoroethylene of Claim 1 or 2 whose temperature of the said hydrogen is 0-950 degreeC.   The manufacturing method of the trifluoroethylene of any one of Claims 1-3 whose temperature of the said tetrafluoroethylene 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 is one or more selected from the group consisting of water vapor, nitrogen and carbon dioxide.   The supply amount of the heat medium supplied to the reactor is 20 to 98% by volume with respect to the total gas supplied to the reactor, of trifluoroethylene according to any one of claims 1 to 6. Production method.   In the step (c), the contact time between the tetrafluoroethylene and hydrogen supplied into the reactor and the heat medium is 0.01 to 10 seconds. The method for producing trifluoroethylene according to Item.   After the step (c), the method includes (d) a step of taking out the reaction mixture containing the trifluoroethylene produced in the reactor from the reactor, and the tetrafluoroethylene and the hydrogen in the step (a). Supply to the reactor, supply of the heat medium in the step (b) to the reactor, hydrogen and tetrafluoroethylene in the reactor in the step (c), and the heat medium The method for producing trifluoroethylene according to any one of claims 1 to 8, wherein the contact and the removal of the reaction mixture from the reactor in the step (d) are continuously performed.

Images