JPWO2013146709A1 - Process for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene - Google Patents

Abstract

It provides an economically advantageous method for producing industrially useful HFO-1234yf and VdF in a single reaction involving pyrolysis using raw materials that are easily procured. Provided is a method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene from octafluorocyclobutane and chloromethane by a one-stage reaction process including a synthesis reaction involving thermal decomposition.

Description

  The present invention relates to a process for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene, and in particular, 2,3,3,3 in a single reaction from octafluorocyclobutane and chloromethane. -Relates to a process for producing tetrafluoropropene and 1,1-difluoroethylene.

  In recent years, 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been highly expected as a new refrigerant to replace 1,1,1,2-tetrafluoroethane (HFC-134a), which is a greenhouse gas. It has been. In the present specification, for halogenated hydrocarbons, the abbreviations of the compounds are described in parentheses after the compound names. In the present specification, the abbreviations are used instead of the compound names as necessary.

  As a method for producing HFO-1234yf, for example, 1,1-dichloro-2,2,3,3,3-pentafluoropropane (HCFC-225ca) is dehydrofluorinated with an alkaline aqueous solution in the presence of a phase transfer catalyst. 1,1-dichloro-2,3,3,3-tetrafluoropropene (CFO-1214ya) obtained by the above process is used as a synthetic raw material, and a method of reducing it with hydrogen is known (for example, Patent Document 1). reference). However, such a method has a problem that the equipment cost increases because of the multi-stage reaction, and it is difficult to distill and purify the intermediate product and the final product.

  Further, 1,1-difluoroethylene (VdF) is a fluorine compound industrially useful as a raw material for fluororesins such as polyvinylidene fluoride widely used as a water treatment filter, for example. This VdF is also produced by a multi-step reaction method similar to the above-mentioned HFO-1234yf, resulting in high equipment costs and difficulty in distillation and purification of intermediate products and final products. It was.

Japanese Patent No. 3778298

  The present invention has been made from the above viewpoint, and is economically advantageous for producing industrially useful HFO-1234yf and VdF in a single reaction involving thermal decomposition, using raw materials that are easily procured. It aims to provide a method.

  In the present invention, 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1,1-difluoroethylene (HFO-1234yf) are synthesized from octafluorocyclobutane (RC318) and chloromethane (R40) by a synthetic reaction involving thermal decomposition. A process for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene is provided.

  According to the production method of the present invention, industrially useful HFO-1234yf and VdF can be produced using RC318 and R40 which are easily procured as raw materials.

It is a figure which shows an example of the reaction apparatus which can be used for the manufacturing method of this invention. It is a figure which shows another example of the reaction apparatus which can be 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-1234yf and VdF by a synthesis reaction involving thermal decomposition using RC318 and R40 as raw materials.
The main reaction in which HFO-1234yf and VdF are produced from RC318 and R40 by a synthetic reaction involving thermal decomposition is shown in the following formula (1).

Difluorocarbene (F ₂ C :) is produced from RC318 by a thermal decomposition reaction, and difluorocarbene (F ₂ C :) and R40 are subjected to a direct addition reaction or through one or more intermediates to produce tetrafluoropropene. (Especially HFO-1234yf) or VdF.

The synthesis reaction involving thermal decomposition is usually performed by mixing RC318 and R40 in advance or separately supplying them to the reactor and retaining them in the reactor at a predetermined temperature for a predetermined time.
The production method of the present invention may be a continuous production method or a batch production method. The production method of the present invention is preferably a continuous method in terms of production efficiency.

<Raw material>
RC318 and R40 are used as raw materials for the production of HFO-1234yf and VdF of the present invention. The ratio of R40 and RC318 in the raw material is preferably such that RC318 is 0.001 to 10 moles per mole of R40. By setting the molar ratio of C318 to R40 in the raw material (hereinafter referred to as “RC318 / R40”) within the above range, the conversion rate of the raw material components, particularly the conversion rate of R40, can be increased. Moreover, the ratio of components other than HFO-1234yf and VdF, that is, by-products, in the obtained reaction product can be suppressed. The molar ratio RC318 / R40 is more preferably in the range of 0.001 to 5, particularly preferably in the range of 0.01 to 2.

In addition to these two components, the raw material is a fluorine-containing compound that can be thermally decomposed to generate F ₂ C :, for example, chlorodifluoromethane (R22), tetrafluoroethylene (TFE), hexafluoropropene (HFP), chlorotrifluoride. Fluoroethylene (CTFE), trifluoroethylene, hexafluoropropylene oxide (HFPO) can be contained.
Hereinafter, a fluorine-containing compound other than RC318 that can be thermally decomposed in a reactor to generate F ₂ C: is referred to as “TFE or the like”.

From the fluorine-containing compound capable of generating F ₂ C: upon thermal decomposition and R40, as described above, a synthetic reaction involving thermal decomposition (hereinafter also referred to as “thermal decomposition / synthesis reaction”) causes HFO-1234yf. And VdF. Here, RC318 used as a raw material component in the production method of the present invention is a fluorine-containing compound that itself can be thermally decomposed to generate F ₂ C :, and at the same time, the above pyrolysis generates F ₂ C :. It is also a component by-produced when producing HFO-1234yf and VdF by thermal decomposition / synthesis reaction of R40 with a possible fluorine-containing compound.

  Therefore, in the present invention, RC318 newly prepared as the raw material component RC318 may be used, and a by-product is produced when HFO-1234yf and VdF are produced by thermal decomposition / synthesis reaction of a composition containing TFE and R40. RC318 may be used.

  When these raw material components are pyrolyzed / synthesized in the reactor, the raw material components may be supplied to the reactor separately or may be mixed in advance. It is preferable that the supply of each component of the raw material to the reactor is carried out by adjusting the molar ratio represented by RC318 / R40 within the above range. In the embodiment in which the raw material components are continuously passed through the reactor and the thermal decomposition / synthesis reaction is performed, the supply amount of the raw material components is indicated by the supply amount per unit time.

<Thermal decomposition / synthesis reaction>
The temperature at which the raw materials containing RC318 and R40 are subjected to thermal decomposition / synthesis reaction, that is, the reaction temperature is preferably 400 to 1200 ° C. The reaction temperature is more preferably in the range of 600 to 900 ° C, particularly preferably in the range of 710 to 950 ° C. By setting the reaction temperature in the range of 400 to 1200 ° C., the reaction rate of the thermal decomposition / synthesis reaction can be increased, and HFO-1234yf and VdF can be obtained efficiently.

  Adjustment of reaction temperature is performed by heating a raw material within a reactor. Examples of the heating method include a method in which the reactor is heated by a heating means such as an electric heater, and a raw material is heated by using a heat medium. From the viewpoint of facilitating reaction control, a method of heating the raw material using a heat medium is preferable. In that case, a heating means such as an electric heater may be used as an auxiliary. The method for controlling the reaction temperature using a heat medium is as described later.

  The temperature of RC318 supplied to the reactor or the temperature of TFE or the like supplied to the reactor is preferably 0 to 600 ° C. from the viewpoint that the reactivity is high to some extent but is not easily carbonized. From the viewpoint of increasing the reactivity, it is preferable to heat RC318, TFE, or the like to normal temperature (25 ° C.) or higher and 600 ° C. or lower, and more preferably 100 to 500 ° C. before introducing them into the reactor. .

  Moreover, it is preferable that the temperature of R40 supplied to a reactor shall be 0-1200 degreeC from a reactive viewpoint. From the standpoint of further increasing the reactivity, it is preferable to heat R40 to normal temperature or higher and 1200 ° C or lower, and more preferably 100 to 800 ° C before introducing R40 into the reactor.

  The raw material components such as RC318 and R40, and TFE used as necessary may be supplied to the reactor separately or may be supplied after mixing the respective components. When supplying each component after mixing it, divide each raw material component into groups, for example RC318 and TFE, etc. and other, mix each component in each group and supply separately to the reactor Alternatively, all components may be mixed and then supplied. In consideration of the difference in temperature conditions, RC318 or a mixture of RC318 and TFE or the like is adjusted to the above preferable temperature condition and supplied to the reactor, and separately from this, R40 is adjusted to the above preferable temperature condition and reacted. It is preferable to supply to the vessel.

  The pressure at which RC318 and R40 are pyrolyzed / synthesized, that is, the reaction pressure, is preferably 0 to 2.0 MPa in gauge pressure, and more preferably in the range of 0 to 0.5 MPa. The reaction pressure usually corresponds to the pressure (gauge pressure) in the reactor where the pyrolysis / synthesis reaction is performed.

  The time for causing thermal decomposition / synthesis reaction between RC318 and R40, that is, the reaction time is preferably 0.01 to 10 seconds, and more preferably 0.2 to 3.0 seconds. By setting the reaction time to 0.01 to 10 seconds, the production reaction of HFO-1234yf and VdF can sufficiently proceed and the production of by-products can be suppressed. The reaction time 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 reactor for thermally decomposing / synthesizing RC318 and R40 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.

<Manufacturing method using heat medium>
In the method for producing HFO-1234yf and VdF by a synthesis reaction involving thermal decomposition using RC318 and R40 according to the present invention, it is preferable to perform the thermal decomposition / synthesis reaction in the presence of a heat medium as described above.

Specific examples of the method for carrying out the pyrolysis / synthesis reaction in the presence of a heat medium include the following steps.
(A) A step of mixing RC318 and R40 in advance or separately supplying them to the reactor;
(B) A step of supplying a heat medium to the reactor.
(C) The process which makes RC318 and R40 contact a heat carrier within a reactor, and produces | generates HFO-1234yf and VdF.

  The production method of HFO-1234yf and VdF of the present invention performed in the presence of a heat medium may be a continuous production method or a batch production method as described above. In the continuous production method, RC318 and R40 are supplied to the reactor, a heating medium is supplied to the reactor, and a reaction mixture containing HFO-1234yf and VdF generated in the reactor is removed from the reactor (hereinafter, referred to as “reaction mixture”). (D) process) is performed continuously. That is, the steps (a), (b), and (d) are performed simultaneously. 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 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 the reactor.

  Even when the production method of the present invention is carried out in the presence of a heat medium, it is preferably a continuous method in terms of production efficiency, as described above. Hereinafter, an embodiment in which the method of the present invention performed in the presence of a heat medium is applied to continuous production will be described.

  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 a temperature of 100 to 1200 ° C. The heat medium is preferably at least one selected from water vapor, nitrogen and carbon dioxide. Further, it is more preferable to use a gas containing 50% by volume or more of water vapor and the balance being nitrogen and / or carbon dioxide. From the viewpoint of removing HCl produced by the thermal decomposition reaction as hydrochloric acid, the content ratio of water vapor in the heat medium is preferably 50% by volume or more, and the use of a gas substantially consisting of only water vapor (100% by volume) is particularly preferred.

The supply ratio of the heat medium is preferably a ratio of 20 to 98% by volume, more preferably 50 to 95% by volume in a total of 100% by volume of the supply of the heat medium and the raw material. By setting the ratio of the supply amount of the heat medium in the total supply amount of the heat medium and the raw material to 20% by volume or more, the thermal decomposition / synthesis reaction is advanced while suppressing the formation of high boilers and carbonization of the raw material. , HFO-1234yf and VdF can be produced efficiently. Moreover, when the said ratio exceeds 98 volume%, productivity will fall.
Further, the temperature of the heat medium supplied to the reactor is preferably 100 to 1200 ° C. from the viewpoint of thermal decomposition and 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 introduced into the reactor is more preferably 600 to 900 ° C, and particularly preferably 700 to 900 ° C.

The preferred reaction temperature, reaction pressure, and reaction time when the production method of the present invention is carried out using a heat medium are the same as described above. When a heat medium is used, the operation of bringing the raw material and the heat medium into contact with each other in the reactor corresponds to the operation of causing the pyrolysis / synthesis reaction. Accordingly, the reaction temperature is the temperature at the time of contact of the raw material with the heat medium, and the reaction time corresponds to the contact time of the raw material with the heat medium. 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.
Furthermore, the method for supplying the raw material to the reactor, the temperature conditions, and the like can be the same as described above.

Moreover, the method which has the following process as the method other than the above which performs the said thermal decomposition / synthesis reaction in presence of a heat medium is also mentioned.
(I) supplying a mixture obtained by premixing R40 and the heat medium to the reactor;
(Ii) supplying RC318 to the reactor.
(Iii) A step of bringing HFO-1234yf and VdF into contact with a mixture of RC318, R40 and a heat medium in a reactor.
The above method may be a continuous production method or a batch production method as described above, but a continuous production method is preferred. In the continuous production method, the mixture of R40 and the heat medium previously mixed in step (i) is supplied to the reactor, the RC318 is supplied to the reactor in step (ii), and the HFO produced in the reactor is supplied. The removal of the reaction mixture containing −1234yf and VdF from the reactor (hereinafter referred to as step (iv)) is continuously performed. That is, step (i), step (ii), and step (iv) are performed simultaneously. In the batch type production, either the first or the second of the supply of the mixture obtained by previously mixing R40 and the heat medium in the step (i) and the supply of the RC 318 in the step (ii) may be performed. That is, when one of RC 318 and the mixture in which R40 and the heat medium are mixed in advance are supplied, the previously supplied R40 and the heat medium are mixed in advance even when the other is not supplied in the reactor. During the stay of the mixture or RC318, components to be supplied later are supplied, and the mixture obtained by previously mixing R40 and the heat medium may be in contact with RC318 in the reactor for a predetermined time.
In the above method, the heat medium similar to the above-described method can be used as the heat medium, and the supply ratio of the heat medium and the reaction temperature condition can be the same as those in the above-described method.

<Reactor>
FIG. 1 shows an example of a reaction apparatus used for producing HFO-1234yf and VdF using RC318 and R40 in the presence of a heat medium in the production method of the present invention.
This reaction apparatus 20 has a reactor 1 provided with heating means such as an electric heater. The reactor 1 is connected with a supply line 2 for R40 as a first raw material component, a supply line 3 for RC318 as a second raw material component, and a supply line 4 for steam as a heating medium as shown below. Has been. In addition, installation of the heating means in the reactor 1 is not essential.

  The R40 supply line 2 and the RC 318 supply line 3 are provided with preheaters (preheaters) 2a and 3a each equipped with an electric heater or the like, and each supplied raw material component is preheated to a predetermined temperature. It is supplied to the reactor 1. In addition, a superheated steam generator 4a is installed in the steam supply line 4, and the temperature and pressure of the supplied steam are adjusted by mixing with the superheated steam.

These supply lines 2, 3, 4 may be connected to the reactor 1 separately, but some or all of the supply lines are connected before the reactor 1 and connected to the reactor 1. Also good. For example, as shown in FIG. 1, by connecting the supply lines 2 and 3 after passing through the preheaters 2a and 3a, a mixture of RC318 and R40 is transferred from the raw material supply line 5 to the reactor 1. The supplied steam may be configured to be supplied from the steam supply line 4 to the reactor 1 separately from the raw material mixing supply line 5.
Further, as shown in FIG. 2, by connecting the supply lines 2 and 4 after passing through the preheaters 2a and 4a, a mixture in which R40 and water vapor are mixed is supplied to the reactor 1 from the mixed supply line 5 ′. RC318 may be configured to be supplied to the reactor 1 from the supply line 3 after passing through the preheater 3a, separately from the mixing supply line 5 ′.

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).
A reaction mixture containing HFO-1234yf and VdF was taken out from the reactor 1 and obtained by removing acidic substances such as hydrogen chloride, water vapor, water, etc. by the treatment after the outlet line 7 as described above. The gas is hereinafter referred to as outlet gas.

<Outlet gas component>
In the production method of the present invention, HFO-1234yf and VdF can be obtained as components of the outlet gas. As compounds other than HFO-1234yf and VdF contained in the outlet gas, methane, ethylene, R22, TFE, HFP, CTFE, trifluoroethylene, 1,3,3,3-tetrafluoropropene (HFO-1234ze), 1 , 2-difluoroethylene and the like.

Among these components, methane and ethylene having a methylene group (═CH ₂ ) or a methyl group (—CH ₃ ) are compounds derived from the raw material component R40, and have a fluorine atom, R22, TFE, HFP. , CTFE, trifluoroethylene, HFO-1234ze, and 1,2-difluoroethylene are all compounds derived from RC318 as a raw material component. HFO-1234yf and VdF, and HFO-1234ze and 1,2-difluoroethylene are compounds derived from RC318 and compounds derived from R40. The exit gas usually contains RC318 and R40 which are unreacted raw material components in addition to these.

The above components other than HFO-1234yf and VdF contained in the outlet gas can be removed to a desired extent by known means such as distillation. The separated R22, TFE, HFP, CTFE, and trifluoroethylene and RC318 as an unreacted raw material component are compounds that can generate F ₂ C: and can be recycled as a part of the raw material. . Similarly, R40 as an unreacted raw material component contained in the outlet gas is isolated as necessary, or separated together with a compound capable of generating F ₂ C: and can be recycled.

  According to the production method of the present invention, it is possible to efficiently produce HFO-1234yf useful as a new refrigerant having a small global warming potential (GWP) of 4 in one reaction using RC318 and R40 as raw materials. . For example, the production method of the present invention reduces the cost required for raw materials and production equipment as compared to a method that requires a multistage reaction in which HFO-1234yf is produced via CFO-1214ya using HCFC-225ca as a raw material. Not only can be reduced, but the energy required for manufacturing can be greatly reduced. In addition to HFO-1234yf, VdF, which is a raw material for polyvinylidene fluoride (for example, industrially used as a water treatment filter), can be produced, and a material that is important for maintaining the global environment has low energy. Thus, it can be manufactured at a low cost at the same time.

  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-1234yf and crude VdF were obtained from a raw material gas composed of RC318 and R40 as follows.

  R40 was continuously introduced into a stainless steel tube in an electric furnace set at a furnace temperature of 250 ° C., and R40 was heated to 250 ° C. Moreover, RC318 was continuously introduce | transduced into the stainless steel tube in the electric furnace set to the furnace temperature of 250 degreeC, and RC318 was heated to 250 degreeC.

  These raw material gas components (R40 and RC318) that have been preheated and adjusted to the above temperature, and steam (water vapor) heated by an electric furnace set at a furnace temperature of 800 ° C., are used as the molar amount of the raw material components supplied. The internal pressure (gauge pressure) is such that the ratio is RC318 / R40 = 1.0, and the supply ratio of water vapor to the total gas supply amount is water volume / (R40 + RC318 + water vapor) × 100 = 90%. The reactor was supplied to a reactor controlled at 0.02 MPa and an internal temperature of 800 ° C. Hereinafter, all the pressures are assumed to be gauge pressures.

  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 0.63 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 800 ° C., and the actually measured value of the reactor internal pressure was 0.02 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 heating (preheating) temperature of R40 and RC318 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.

  Moreover, based on the molar composition of the exit gas obtained by the analysis by gas chromatography, the yield and conversion rate (reaction rate) of RC318 and the yield and selectivity of each component derived from RC318 were determined. These results are shown in the lower column of Table 1.

The above values mean the following respectively.
(RC318 yield)
The ratio (mol%) which RC318 occupies among the RC318 origin components (component which has a fluorine atom) in outlet gas.
(RC318 conversion rate (reaction rate))
Among the RC318-derived components in the outlet gas, when the proportion of RC318 (RC318 yield) is X%, (100-X)% is referred to as the conversion rate (reaction rate) of RC318. It means the ratio (mol%) of RC318 reacted.
(Yield of each component derived from RC318)
The ratio (mol%) which each compound other than RC318 occupies among the components derived from RC318 in the outlet gas.
(Selectivity of each component derived from RC318)
Among the reacted RC318, the percentage converted to each component other than RC318 is the percentage of each. The selectivity of each component is determined by “yield of each component derived from RC318” / “conversion rate (reaction rate) of RC318”.

[Example 2]
The reaction was carried out under the same conditions as in Example 1 except that 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 0.31 seconds. Next, 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 2 except that the set temperature of the electric furnace for heating the steam was 850 ° C. That is, the reaction was carried out under the same conditions as in Example 2 except that the internal temperature in the reactor was controlled at 850 ° C. Next, 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.

  As can be seen from Table 1, HFO-1234yf and VdF could be produced by directly carrying out pyrolysis / synthesis reaction using RC318 and R40 as raw materials.

According to the production method of the present invention, industrially useful HFO-1234yf and VdF can be produced using RC318 and R40 which are easily procured as raw materials.
The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2012-082047 filed on March 30, 2012 are cited herein as disclosure of the specification of the present invention. Incorporated.

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... R40 supply line, 3 ... RC318 supply line, 4 ... Steam supply line, 2a, 3a ... Preheater (preheater), 4a ... Superheated steam generator, 6 ... Cooling means, 7 ... Outlet line, 8 ... steam and acidic liquid recovery tank, 9 ... alkali washing device, 10 ... dehydration tower, 20 ... reaction device.

Claims (14)

  2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene are produced from octafluorocyclobutane and chloromethane by a synthetic reaction involving thermal decomposition. A process for producing tetrafluoropropene and 1,1-difluoroethylene.   2, 3 according to claim 1, wherein the chloromethane and the octafluorocyclobutane are mixed and reacted at a ratio of 0.001 to 10 mol of the octafluorocyclobutane with respect to 1 mol of the chloromethane. , 3,3-tetrafluoropropene and 1,1-difluoroethylene production method.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to claim 1 or 2, wherein the synthesis reaction is performed at a temperature of 400 to 1200 ° C.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to claim 3, wherein the synthesis reaction is performed at a temperature of 710 to 950C.   The 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 1 to 4, wherein the synthesis reaction is performed at a gauge pressure of 0 to 2.0 MPa. Production method.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 1 to 5, wherein the synthesis reaction time is 0.01 to 10 seconds.   The temperature of the chloromethane subjected to the synthesis reaction is 0 to 1200 ° C, and the 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 1 to 6. Production method.   The 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 1 to 7, wherein the temperature of the octafluorocyclobutane to be subjected to the synthesis reaction is 0 to 600 ° C. Manufacturing method.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 1 to 8, wherein the synthesis reaction is carried out in the presence of a heat medium.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to claim 9, wherein the heat medium comprises at least one selected from water vapor, nitrogen and carbon dioxide.   The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to claim 9 or 10, wherein the temperature of the heat medium is 100 to 1200 ° C. The method for producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to any one of claims 9 to 11, which comprises the following steps.
(A) mixing the octafluorocyclobutane and the chloromethane in advance or separately supplying them to the reactor;
(B) supplying the heat medium to the reactor.
(C) a step of bringing the heat medium into contact with the octafluorocyclobutane and the chloromethane in the reactor to produce the 2,3,3,3-tetrafluoropropene and the 1,1-difluoroethylene.   The 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene according to claim 12, wherein the supply amount of the heat medium is 20 to 98% by volume in the total gas supplied to the reactor. Manufacturing method. Further, after the step (c), the following step (d) is performed, the octafluorocyclobutane and the chloromethane in the step (a) are supplied to the reactor, and the heating medium in the step (b) The 2,3,3,3-tetrafluoropropene according to claim 12 or 13, wherein the supply to the reactor and the removal of the reaction mixture from the reactor in the following step (d) are continuously performed. A method for producing 1,1-difluoroethylene.
(D) A step of taking out from the reactor a reaction mixture containing the 2,3,3,3-tetrafluoropropene and the 1,1-difluoroethylene produced in the reactor.

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