JP6176182B2 - Method for producing trifluoroethylene - Google Patents

Description

  The present invention relates to a method for producing trifluoroethylene.

  Trifluoroethylene (HFO-1123) has a small global warming potential (hereinafter referred to as GWP). Therefore, in recent years, great expectations have been placed on new refrigerants that replace greenhouse gases such as difluoromethane (HFC-32) and 1,1,1,2,2-pentafluoroethane (HFC-125). In the present specification, as described above, for halogenated hydrocarbons, the abbreviation of the compound is described in parentheses after the compound name, and the abbreviation is used instead of the compound name as necessary. In addition, those having a notation such as (E) or (Z) before the compound name or after the abbreviation of the compound indicate that they are E isomers or Z isomers of geometric isomers, and the notation of (E / Z) is It shows that it is a mixture of E body and Z body.

  As a method for producing HFO-1123, chlorotrifluoroethylene (CFO-1113) is reduced with hydrogen in the presence of a palladium or platinum catalyst (for example, see Patent Document 1), 1,1,2-trichloro. A method of reducing -1,2,2-trifluoroethane (CFC-113) with hydrogen in the presence of a catalyst such as palladium (for example, see Patent Document 2) is known.

  However, in the production method using the catalyst described in Patent Documents 1 and 2, preparation of the catalyst, replacement or reactivation of the catalyst accompanying catalyst deactivation, and disposal of the catalyst are necessary, and the production process is complicated. In addition, there is a problem that a polymer by-product is easily generated due to a polymerization reaction of a part of the generated HFO-1123, and the catalyst-filled reactor is clogged by the generated polymer by-product. There is also a problem that the reaction time is long and the productivity is low. Therefore, the production method using a catalyst has many economical disadvantages, and high-purity HFO-1123 cannot be obtained efficiently. Moreover, since the transition metal catalyst is used in any of the methods disclosed in Patent Documents 1 and 2, hydrogen reduction proceeds excessively, and (E) -1,2-difluoroethylene (HFO-1132 (E)) Produces. This HFO-1132 (E) (boiling point: −51 ° C.) had a problem that it was difficult to separate by distillation and purification because the boiling point was very close to that of HFO-1123 (boiling point: −54 ° C.).

  It is also known that HFO-1123 is produced by reacting 1,1,1,2-tetrafluoro-2-chloroethane (HCFC-124) with zinc in a polar aprotic solvent in the presence of a proton source. (For example, see Patent Document 3). However, with this method, the yield of HFO-1123 was extremely low and could not be said to be an efficient production method.

  In addition, a method for producing 1,1,1,2,3,4,4,4-octafluoro-2-butene by pyrolyzing HCFC-124 without using a catalyst is known. However, HFO-1123 cannot be obtained by this method (for example, refer to Patent Document 4).

International Publication 2012/000853 Pamphlet JP-A-9-104647 JP-A-2-258733 Special table 2003-505439 gazette

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a method for producing HFO-1123 capable of producing HFO-1123 with high productivity without using a catalyst. .

This invention provides the manufacturing method of HFO-1123 which has the structure as described in the following [1]-[ 5 ].
[1] A method for producing HCFC-1123, comprising bringing a reducing compound containing a hydrogen atom into contact with HCFC-124 at a temperature of 400 to 1200 ° C. without using a catalyst.
[ 2 ] The HCFC according to [1 ], wherein the reducing compound containing a hydrogen atom is at least one selected from the group consisting of hydrogen, water, a hydrocarbon having 8 or less carbon atoms and a fluorinated hydrocarbon having 8 or less carbon atoms. -1123 production method.
[ 3 ] The method for producing HCFC-1123 according to [1] or [ 2] , wherein a contact time between the reducing compound containing a hydrogen atom and the HCFC-124 is 0.001 to 1000 seconds.
[ 4 ] The ratio of the reducing compound containing a hydrogen atom to the total molar amount (X) of the reducing compound containing the HCFC-124 and the hydrogen atom in the contact is 10 to 98 mol% [1]. The manufacturing method of HCFC-1123 in any one of-[ 3 ].
[ 5 ] The method for producing HCFC-1123 according to any one of [1] to [ 4 ], wherein the reducing compound containing a hydrogen atom is brought into contact with the HCFC-124 at a temperature of 500 to 930 ° C.

  According to the production method of the present invention, using HCFC-124 as a raw material, HFO-1123 can be produced with high productivity without using a catalyst.

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

  The method for producing HFO-1123 of the present invention uses HCFC-124 as a raw material, does not use a catalyst, and contacts HCFC-124 with a reducing compound at a temperature of 400 to 1200 ° C. It is a method of manufacturing. In the contact, in addition to HCFC-124 and the reducing compound, impurities other than HCFC-124 and a diluent gas may be included as necessary.

…（１） The reaction between HCFC-124 and the reducing compound in the production method of the present invention is represented by the following formula (1).

... (1)

  That is, when the raw material HCFC-124 is heated, chlorine radicals (Cl.) Are eliminated by a thermal decomposition reaction, and hydrofluorotrifluoromethyl radicals are generated. The produced hydrofluorotrifluoromethyl radical is considered to produce HFO-1123 with the elimination of the fluorine radical (F.). At this time, it is considered that the reaction for generating HFO-1123 is promoted by heating HCFC-124 in a reducing atmosphere. 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.

  In the present invention, using HCFC-124 as a raw material and carrying out a synthesis reaction involving thermal decomposition at a temperature of 400 to 1200 ° C. while contacting HCFC-124 with a reducing compound, without using a catalyst, HFO-1123 can be manufactured with high productivity. Further, in the production method of the present invention, since no catalyst is used, HCFC-124 is not excessively reduced, has a boiling point close to that of HFO-1123, and is a by-product that is difficult to be separated from HFO-1123, particularly HFO-1123. And HFO-1132 (E) having a very close boiling point can be suppressed.

  In the production method of the present invention, the method for bringing HCFC-124 into contact with the reducing compound is not particularly limited. The said contact can be performed by supplying HCFC-124 and a reducing compound in the field of reaction of HCFC-124 and a reducing compound, for example, a reactor. Hereinafter, the reaction field between HCFC-124 and the reducing compound will be described as a reactor. In the following description, HCFC-124 and the reducing compound are in a gas phase unless otherwise specified.

  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 raw materials HCFC-124 and reducing compound to the reactor, contact of HCFC-124 and reducing compound in the reactor, and HFO-1123 from the reactor The removal is continuously performed.

  In the batch production method, either HCFC-124 as a raw material or reducing compound may be fed into the reactor first or simultaneously. That is, when one of the HCFC-124 and the reducing compound is supplied, even if the other is not supplied into the reactor, the previously supplied component is supplied later while being retained in the reactor. The HCFC-124 and the reducing compound may be in contact with each other for a predetermined time in the reactor.

  The production method of the present invention is preferably a continuous method in terms of productivity. Hereinafter, unless otherwise specified, an embodiment in which the manufacturing method of the present invention is applied to a continuous manufacturing method will be described, but the present invention is not limited thereto.

(Reducing compounds)
The reducing compound is a compound that promotes reduction of HCFC-124 in the reaction represented by the above formula (1). The reducing compound is not particularly limited as long as it has such an action, but a compound containing a hydrogen atom is preferable from the viewpoint of reducing properties. Specific examples of such reducing compounds include hydrogen, water, hydrocarbons having 8 or less carbon atoms, and fluorinated hydrocarbons having 8 or less carbon atoms. As the reducing compound, one of these may be used alone, or two or more may be used in combination.

  The hydrocarbon having 8 or less carbon atoms may be either a saturated hydrocarbon or an unsaturated hydrocarbon, or may be linear, branched or cyclic. Among these, hydrocarbons having 4 or less carbon atoms are preferable because they are easily available, inexpensive, and gaseous at normal temperature and pressure, and methane, ethane, propane, ethylene, and propylene are more preferable. If the reducing compound is a gas at normal temperature and pressure, it is preferable because latent heat for vaporization is unnecessary and it is advantageous in terms of energy.

  The fluorinated hydrocarbon having 8 or less carbon atoms is a compound having one or more hydrogen atoms in which one or more hydrogen atoms of the hydrocarbon having 8 or less carbon atoms are substituted by fluorine atoms.

  The fluorinated hydrocarbon having 8 or less carbon atoms used as the reducing compound is preferably a compound represented by the following formula (2) or (3).

_{C n H 2n + 2-x} F x ... (2)
(However, in the above formula (2), n and x are both natural numbers, and 1 ≦ n ≦ 8 and 1 ≦ x ≦ 2n + 1.)
C _m H _2m-y F _y (3)
(However, in the above formula (3), m and y are both natural numbers, and 1 ≦ m ≦ 8 and 1 ≦ y ≦ 2m−1.)

  In the above formula (2), n is preferably 1 to 4 because it is inexpensive, easily available, and easy to handle because it is a gas at normal temperature and pressure. Moreover, since acquisition is easy, it is preferable that x is 1-8.

  In said formula (3), since it is easy to handle because it is gas at normal temperature normal pressure, it is preferable that m is 1-4. Moreover, since acquisition is easy, it is preferable that y is 1-8.

  Among the fluorocarbons having 8 or less carbon atoms, trifluoromethane (HFC-23), difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoro, among others. Ethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,3,3-hexafluorobutane (HFC-245fa), 2,3, 3,3-tetrafluoropropene (HFO-1234yf), E / Z-1,2,3,3,3-pentafluoropropene (HFO-1234ze (E / Z ) Is more preferably used, and the like.

  As the reducing compound, hydrogen, water, methane, and HFC-32 are more preferable because of easy availability. In addition, water is more preferable because HFO-1123 can be manufactured with high productivity. In addition, water can be easily gas-liquid separated from HFO-1123 at normal temperature and pressure when purifying the target component, HFO-1123. Therefore, if water is used as the reducing compound, the purification process of HFO-1123 is simplified and the productivity of HFO-1123 is improved.

  In the production method of the present invention, even if the ratio of the reducing compound to the total molar amount (X) of HCFC-124 and the reducing compound supplied to the reactor is small, the effect is exhibited. % Is preferred. If the ratio of the reducing compound is 10 mol% or more based on the total molar amount (X), HFO- is suppressed while suppressing side reactions such as the formation of high-boiling substances and carbonization in the synthesis reaction involving thermal decomposition. 1123 can be manufactured with higher productivity. Moreover, since productivity will fall remarkably when the ratio of a reducing compound exceeds 98 mol%, it is not industrially realistic.

  In the present invention, the reducing compound acts as a raw material for HFO-1123 and improves the reaction rate of HCFC-124. Therefore, the ratio of the reducing compound is more preferably 30 mol% or more, and further preferably 50 mol% or more.

  In addition, the reducing compound also has an action as a diluent gas described later. By diluting HCFC-124 with a reducing compound, side reactions can be suppressed. At this time, the dilution effect is improved as the ratio of the reducing compound is increased. However, when the ratio is too large, the ratio of HCFC-124 supplied to the reactor is decreased, and the productivity tends to be lowered. Therefore, the ratio of the reducing compound is more preferably 97 mol% or less, and still more preferably 96 mol% or less.

  From the above viewpoint, the ratio of the reducing compound is more preferably 30 to 97 mol%, and further preferably 50 to 96 mol%. In the production method of the present invention, HFO-1123 can be produced with higher productivity by setting the ratio of the reducing compound in the above-described range.

  In the present embodiment employing the continuous production method, the ratio (mol%) of the reducing compound to the total molar amount (X) of HCFC-124 and the reducing compound is represented by the ratio of the molar flow rate per unit time. It is. In addition, the ratio of the reducing compound is such that when the raw material HCFC-124 is supplied to the reactor as a composition containing impurities, as will be described later, the HCFC-124 in the composition and the reducing compound It is a ratio to the total amount.

(HCFC-124)
In the present invention, the ratio of HCFC-124 to the total molar amount (X) is preferably 2 to 90 mol%, more preferably 3 to 70 mol%, and more preferably 4 to 50 mol% from the viewpoint of productivity. Further preferred.

  In the production method of the present invention, the raw material HCFC-124 may supply HCFC-124 having a purity of 100 mol% to the reactor, and react as a composition containing impurities other than HCFC-124 and HCFC-124. May be supplied to the vessel.

(Impurities other than HCFC-124)
When supplying a composition containing HCFC-124 and impurities other than HCFC-124 to the reactor, examples of impurities other than HCFC-124 include compounds derived from the production of HCFC-124 as a raw material. More _{specifically, C 3 HF l Cl 5-} l compound represented by (0 ≦ l ≦ 5), such as 1,1-dichloro-1,2,2,2-tetrafluoroethane and the like. The compound represented by C ₃ HF ₁ Cl ₅ -1 (0 ≦ l ≦ 5) is, for example, a secondary compound in the production of HCFC-124 by fluorination reaction of 1,1,1,2,2-pentachloropropane. It is a living thing. In addition, 1,1-dichloro-1,2,2,2-tetrafluoroethane is a by-product when HCFC-124 is produced by chlorination reaction of 1,1,1,2-tetrafluoroethane, for example. is there.

  In addition, in the production method of the present invention, the impurities other than HCFC-124 contained in the reaction product when HCFC-124 which is an unreacted raw material is separated from the reaction product described later and recycled as a raw material. It may be a by-product.

  Such impurities are mainly by-products that are difficult to separate from HCFC-124. Specifically, one or more hydrocarbons having 1 to 4 carbon atoms and hydrogen atoms of the hydrocarbons are fluorine atoms. And / or a compound substituted with a chlorine atom. When the impurity is a reducing compound, the ratio of the reducing compound is the sum of the ratio supplied to the reactor as the impurity and the ratio supplied separately to the reactor. The ratio is preferably the predetermined ratio.

  In the present invention, when impurities other than HCFC-124 are supplied to the reactor, the ratio of the impurities to HCFC-124 supplied to the reactor is preferably 50 mol% or less from the viewpoint of productivity. The mol% or less is more preferable, and 10 mol% or less is more preferable.

  The temperature of HCFC-124 supplied to the reactor is not particularly limited as long as HCFC-124 is not decomposed, but from the viewpoint of enhancing the reactivity of HCFC-124, before introducing HCFC-124 into the reactor. For example, it is preferable to heat using a preheater. In this case, HCFC-124 is preferably heated to 100 to 700 ° C, more preferably 200 to 600 ° C. In addition, when supplying HCFC-124 to a reactor as a composition containing HCFC-124 and impurities other than HCFC-124, the temperature of the composition supplied to a reactor should just be made into the said preferable temperature.

  The temperature of the reducing compound supplied to the reactor is not particularly limited as long as the reducing compound does not decompose, and can be 0 ° C. or higher. Further, from the viewpoint of further increasing the reactivity, it is more preferable to heat with a preheater before introducing the reducing compound into the reactor. In this case, the reducing compound is preferably heated to 1200 ° C. or lower, more preferably 100 to 950 ° C., and further preferably 300 to 930 ° C.

  When performing the manufacturing method of this invention by a continuous type, the supply of HCFC-124 and a reducing compound to a reactor may be performed separately, and may be mixed beforehand. When supplying to the reactor after mixing in advance, the temperature at the time of supplying to the reactor is preferably 650 ° C. or less, more preferably 600 ° C. or less from the viewpoint of preventing the decomposition and reaction from proceeding before the reactor. preferable.

(Diluted gas)
In the production method of the present invention, in addition to impurities other than HCFC-124 and HCFC-124 and reducing compounds, dilution gas may be supplied to the reactor for the purpose of adjusting the flow rate or suppressing side reactions. Good. The diluent gas is an inert gas in the reaction of the above formula (1), and examples thereof include nitrogen, carbon dioxide, helium, and argon. Even when such a dilution gas is supplied, the effects of the present invention can be sufficiently obtained. The ratio of the dilution gas supplied to the reactor is preferably 0 to 2400 mol%, more preferably 0 to 1600 mol% with respect to the total molar amount (X) from the viewpoint of productivity of HFO-1123. 1200 mol% is more preferable.

(Reactor)
The reactor for bringing HCFC-124 into contact with the reducing compound is not particularly limited in shape and structure as long as it can withstand the temperature and pressure described below, and includes, for example, a cylindrical vertical reactor. Examples of the material of the reactor include glass, iron, nickel, or an alloy mainly composed of iron and nickel. Further, the reactor may include heating means such as an electric heater.

(Reaction conditions)
The temperature in the reactor is 400 to 1200 ° C., preferably 500 to 1000 ° C., more preferably 500 to 930 ° C., and still more preferably 600 to 900 ° C. in terms of conversion. When the temperature in the reactor is 400 to 1200 ° C., the conversion rate of the synthesis reaction accompanied by thermal decomposition shown by the above formula (1) is increased, and the production of by-products, particularly HFO-1132 (E), is suppressed. And HFO-1123 can be manufactured with high productivity.

  The temperature in the reactor can be controlled by adjusting the temperature and pressure of HCFC-124 and the reducing compound supplied to the reactor. If necessary, the inside of the reactor can be supplementarily heated with an electric heater, a microwave generator or the like.

  The contact time between HCFC-124 and the reducing compound is preferably 0.001 to 1000 seconds, more preferably 0.001 to 100 seconds, still more preferably 0.01 to 10 seconds, and particularly preferably 0.05 to 5 seconds. . When the contact time is 0.001 to 1000 seconds, the synthesis reaction involving thermal decomposition of HFO-1123 proceeds sufficiently, and HFO-1123 can be produced with high productivity. The contact time between HCFC-124 and the reducing compound corresponds to the residence time of HCFC-124 and the reducing compound in the reactor, and the supply amount (flow rate) of the HCFC-124 and the reducing compound to the reactor. ) Can be controlled by adjusting.

  In the embodiment of the present invention, the pressure in the reactor at the time of contacting HCFC-124 and the reducing compound is preferably 0 to 2.0 MPa, more preferably 0 to 0.5 MPa. Moreover, you may react by negative pressure. The pressure in the reactor is particularly preferably atmospheric pressure (atmospheric pressure) from the viewpoint of handleability. In addition, unless otherwise indicated in this specification, a pressure shows a gauge pressure.

(Reactor)
An example of the reaction apparatus used in the production method of the present invention will be described with reference to FIG.
The reaction apparatus 20 includes a reactor 1. A supply line 2 for HCFC-124 and a supply line 3 for a reducing compound are connected to the reactor 1 as shown below. Moreover, it is preferable that the reactor 1 is provided with heating means, such as an electric heater. The supply line 2 of HCFC-124 and the supply line 3 of the reducing compound may be separately connected to the reactor 1, but may be connected before the reactor 1 and connected to the reactor. . For example, as shown in FIG. 1, a mixture of HCFC-124 and a reducing compound is reacted from a mixture supply line 4 by connecting a supply line 2 of HCFC-124 and a supply line 3 of a reducing compound. You may comprise so that it may be supplied to the container 1. FIG.

  The supply line 2 of the HCFC-124 and the supply line 3 of the reducing compound are provided with preheaters (preheaters) 2a and 3a each equipped with an electric heater or the like. In order to efficiently raise the HCFC-124 and the reducing compound to a predetermined reaction temperature in the reactor 1, the HCFC-124 and the reducing compound supplied to the reactor 1 are respectively preheater (preheater) 2a. , 3a is preferably preheated to a predetermined temperature and then supplied to the reactor 1. Although it is not essential to install the preheaters (preheaters) 2a and 3a, it is preferable to install them. When the reducing compound is water, a heated steam generator 3a is preferably used as the preheater (preheater) 3a, thereby adjusting the temperature and pressure of the supplied water (steam).

  An outlet line 6 in which a cooling means 5 such as a heat exchanger is installed is connected to the outlet of the reactor 1. In the outlet line 6, a water vapor and acidic liquid recovery tank 7, an alkali cleaning device 8 and a dehydration tower 9 are further installed in this order. Then, after dehydration by the dehydration tower 9, the components in the obtained reaction mixture are analyzed and quantified by an analyzer such as gas chromatography (GC). In addition, the reaction mixture containing HFO-1123 was taken out from the reactor 1, and was obtained by removing acidic substances such as hydrogen chloride and hydrogen fluoride, water vapor, and water by the treatment after the outlet line 6 as described above. Hereinafter, the gas is referred to as “exit gas”.

(Outlet gas)
In the synthesis reaction involving thermal decomposition of HCFC-124, a composition containing HFO-1123, which is the target product, can be obtained as the outlet gas. As compounds other than HFO-1123 contained in the outlet gas, in addition to HCFC-124 which is an unreacted raw material, carbon monoxide, carbon dioxide, HFO-1132 (E / Z), 1,1-difluoroethylene ( HFO-1132a), 1,1,2-trifluoroethane (HFC-143), fluoroethylene (HFO-1141), 1-chloro-2,2-difluoroethylene (HFO-1122), tetrafluoroethylene (FO- 1114), chlorotrifluoroethylene (CFO-1113), 3,3-difluoropropene (HFO-1252zf), 3,3,3-trifluoropropene (HFO-1243zf), HFO-1234yf, HFO-1234ze (E / Z), hexafluoropropene (HFO-1216), E / Z-1,2,3 3,3-pentafluoropropene (HFO-1225ye (E / Z)), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 1-chloro-1,1,2,2-tetra Fluoroethane (HCFC-124a), HFC-125, HFC-134, HFC-134a, HFC-143a, 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), HFC-227ea , HFC-236fa, 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), tetrafluoromethane (FC-14), HFC-23, HFC-32, fluoromethane (HFC-41) , Chlorotrifluoromethane (CFC-13), dichlorodifluoromethane (CFC-12), chlorodifluoromethane (HC) C-22) and octafluorocyclobutane (RC318), and the like.

  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. At this time, a compound having a boiling point close to that of HFO-1123 (boiling point: −54 ° C.), for example, HFO-1132 (E) (boiling point: −51 ° C.), can be separated and purified by ordinary separation and purification techniques (distillation, etc.) Have difficulty. According to the production method of the present invention, since it is possible to suppress the formation of such by-products that are difficult to be separated from HFO-1123, a general distillation apparatus or the like can be used without using a special purification method or apparatus. Highly purified HFO-1123 can be produced.

  In the production method of the present invention, unreacted HCFC-124 can be separated from the reaction mixture or outlet gas by distillation or the like, and returned to the reactor as a part of the raw material (recycling). Thereby, productivity of HFO-1123 can be improved more.

  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 10 are examples, and example 11 is a comparative example.

(Example 1)
Using the same reaction apparatus as shown in FIG. 1, crude HFO-1123 was obtained from HCFC-124 as follows.
HCFC-124 was continuously introduced into the preheater 2a of the stainless steel tube in the electric furnace set at a furnace temperature of 350 ° C., and the HCFC-124 was heated to 350 ° C.
Water (steam) heated by a heated steam generator 3a, which is an electric furnace set to a furnace temperature of 750 ° C., was supplied to a reactor controlled at an internal temperature (gauge pressure) of 0.04 MPa and an internal temperature of 770 ° C. Further, HCFC-124 that was preheated and adjusted to the above temperature was supplied to the reactor so that the supply ratio of water vapor (water vapor / (HCFC-124 + water vapor)) to the total gas supply amount was 93 mol%. .

  The flow rate (supply amount per unit time) of the mixed gas is controlled so that the residence time of the mixed gas (HCFC-124 and water vapor) in the reactor is 0.31 seconds, and the gas of the reaction mixture is supplied to the reactor. Removed from the exit. The actually measured value of the reactor internal temperature was 770 ° 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 HCFC-124 and water vapor 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.

  Further, based on the molar composition of the outlet gas obtained by analysis by gas chromatography, HCFC-124, HFO-1123, HFO-1132a, HFC-134a, HFO-1122, HFO-1216, and HFO in the outlet gas The molar ratio of −1132 (E) was calculated. Furthermore, the conversion rate (reaction rate) of HCFC-124 was obtained, and the selectivity of each component derived from HCFC-124 was calculated. Furthermore, HFO-1132 (E) / HFO-1123 (molar ratio) was determined. These results are shown in the lower column of Table 1.

(HCFC-124 conversion rate (reaction rate))
HCFC-124 conversion rate (reaction rate) is (100-Y) when the proportion of unreacted HCFC-124 is Y% with respect to the total of components derived from HCFC-124 in the outlet gas. % Is referred to as the conversion rate (reaction rate) of HCFC-124. It means the ratio (mol%) of reacted HCFC-124. Here, in a present Example, the component derived from HCFC-124 means HCFC-124, HFO-1123, HFO-1132a, HFC-134a, HFO-1212, HFO-1216, and HFO-1132 (E).

(Selectivity of each component derived from HCFC-124)
The selectivity of each component derived from HCFC-124 refers to the ratio (mol%) converted to each component in the reacted HCFC-124. The selectivity of each component is determined by “yield of each component derived from HCFC-124” / “conversion rate (reaction rate) of HCFC-124”. In addition, the yield of each component derived from HCFC-124 means a ratio (mol%) occupied by each component other than HCFC-124 in the components derived from HCFC-124 in the outlet gas.

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

(Examples 2-7)
The reaction was carried out under the same conditions as in Example 1 except that the set temperature of the electric furnace for heating water and the residence time of the mixed gas in the reactor were controlled as follows. 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 2)
The set temperature of the electric furnace for heating water was 820 ° C., and the reactor internal temperature (actual measurement value) was controlled at 820 ° C. Further, the flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 0.30 seconds.

(Example 3)
The set temperature of the electric furnace for heating water was 650 ° C., and the reactor internal temperature (actual measurement value) was controlled at 650 ° C. Further, the flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 0.31 seconds.

(Example 4)
The preset temperature of the electric furnace for heating water was set to 700 ° C., and the reactor internal temperature (actual measurement value) was controlled to 700 ° C. Further, the flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 0.31 seconds.

(Example 5)
The set temperature of the electric furnace for heating water was 750 ° C., and the reactor internal temperature (actual measurement value) was controlled at 750 ° C. Further, the flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 0.31 seconds.

(Example 6)
The set temperature of the electric furnace for heating water was 750 ° C., and the reactor internal temperature (actual measurement value) was controlled at 750 ° C. The flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 1.21 seconds. In Example 6, HCFC-124 was supplied to the reactor so that the molar ratio represented by water vapor / (HCFC-124 + water vapor) was 92 mol%.

(Example 7)
The set temperature of the electric furnace for heating water was 950 ° C., and the reactor internal temperature (actual measurement value) was controlled at 950 ° C. Further, the flow rate of the mixed gas was controlled so that the residence time of the mixed gas in the reactor was 0.30 seconds. In Example 7, HCFC-124 was supplied to the reactor so that the molar ratio represented by water vapor / (HCFC-124 + water vapor) was 92 mol%.

(Example 8)
As the reducing compound, methane (CH ₄ ) was used instead of water, and the methane was heated by an electric furnace set at a furnace temperature of 400 ° C. Thereafter, the heated methane was supplied to a reactor whose internal temperature (actual measurement value) was controlled at 750 ° C. Further, HCFC-124 preheated in the same manner as in Example 1 was supplied to the reactor so that the molar ratio represented by methane / (HCFC-124 + methane) was 95 mol%. The flow rate of the mixed gas was controlled so that the residence time of the mixed gas of HCFC-124 and methane in the reactor was 1.00 seconds. Otherwise, the reaction was carried out under the same conditions as in Example 1. 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 9)
As the reducing compound, hydrogen (H ₂ ) was used instead of water, and the hydrogen was heated by an electric furnace set at a furnace temperature of 400 ° C. Thereafter, heated hydrogen was supplied to a reactor whose internal temperature (actual measurement value) was controlled at 750 ° C. Further, HCFC-124 preheated in the same manner as in Example 1 was supplied to the reactor so that the molar ratio represented by hydrogen / (HCFC-124 + hydrogen) was 95 mol%. The flow rate of the mixed gas was controlled so that the residence time of the mixed gas of HCFC-124 and hydrogen in the reactor was 1.00 seconds. Otherwise, the reaction was carried out under the same conditions as in Example 1. 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 10)
As the reducing compound, HFC-32 was used instead of water, and HFC-32 was heated by an electric furnace set at a furnace temperature of 400 ° C. Thereafter, the heated HFC-32 was supplied to a reactor whose internal temperature (measured value) was controlled at 750 ° C. Further, HCFC-124 preheated in the same manner as in Example 1 was supplied to the reactor so that the molar ratio represented by HFC-32 / (HCFC-124 + HFC-32) was 95 mol%. The flow rate of the mixed gas was controlled so that the residence time of the mixed gas of HCFC-124 and HFC-32 in the reactor was 1.00 seconds. Otherwise, the reaction was carried out under the same conditions as in Example 1. 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 11)
Nitrogen (N ₂ ) was used in place of the reducing compound, and the nitrogen was heated by an electric furnace set at a furnace temperature of 400 ° C. Thereafter, heated nitrogen was supplied to a reactor in which the internal temperature (measured value) was controlled to 800 ° C. and the internal pressure was controlled to 0.07 MPa. Further, HCFC-124 preheated in the same manner as in Example 1 was supplied to the reactor so that the molar ratio represented by nitrogen / (HCFC-124 + nitrogen) was 91 mol%. The flow rate of the mixed gas was controlled so that the residence time of the mixed gas of HCFC-124 and HFC-32 in the reactor was 1.10 seconds. Otherwise, the reaction was carried out under the same conditions as in Example 1. 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.

  From Table 1, in Examples 1-10, HFO-1123 was obtained without using a catalyst by performing a synthesis reaction involving thermal decomposition using HCFC-124 as a raw material in the presence of a reducing compound. I understand. Moreover, in Examples 1-10, it turns out that the production | generation of HFO-1132 (E) which is a by-product with a boiling point near HFO-1123 was suppressed. In contrast, in Example 11 using nitrogen instead of the reducing compound, HFO-1123 was not obtained.

  Furthermore, it turns out that HFO-1123 was obtained with high conversion and high selectivity in Examples 1-7 which used water as a reducing compound among above-mentioned Examples.

  According to the production method of the present invention, HFO-1123 can be produced with high productivity without using a catalyst. Moreover, according to the manufacturing method of this invention, the production | generation of the by-product which is difficult to distill and separate with HFO-1123 like HFO-1132 (E) can be suppressed.

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Supply line of HCFC-124, 3 ... Steam supply line, 2a ... Preheater (preheater), 3a ... Heated steam generator, 4 ... Raw material mixing supply line, 5 ... Cooling means, 6 ... Outlet line, 7 ... steam and acidic liquid recovery tank, 8 ... alkaline washing device, 9 ... dehydration tower, 20 ... reactor.

Claims (5)

A reducing compound containing a hydrogen atom and 1,1,1,2-tetrafluoro-2-chloroethane are contacted at a temperature of 400 to 1200 ° C. without using a catalyst. Production method. The trifluoro according to claim 1, wherein the reducing compound containing a hydrogen atom is one or more selected from the group consisting of hydrogen, water, hydrocarbons having 8 or less carbon atoms, and fluorinated hydrocarbons having 8 or less carbon atoms. A method for producing ethylene. The trifluoroethylene according to claim 1 or 2 , wherein a contact time between the reducing compound containing a hydrogen atom and the 1,1,1,2-tetrafluoro-2-chloroethane is 0.001 to 1000 seconds. Manufacturing method. The ratio of the reducing compound containing a hydrogen atom to the total molar amount (X) of the reducing compound containing the 1,1,1,2-tetrafluoro-2-chloroethane and the hydrogen atom in the contact is 10 to 10. It is 98 mol%, The manufacturing method of the trifluoroethylene of any one of Claims 1-3 . The trifluoroethylene according to any one of claims 1 to 4 , wherein the reducing compound containing a hydrogen atom and the 1,1,1,2-tetrafluoro-2-chloroethane are contacted at a temperature of 500 to 930 ° C. Manufacturing method.

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