JP2012519654A - Method for producing fluorine-containing propene containing 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene - Google Patents

Abstract

The present invention reacts 1,1,1,3-tetrachloro-3-fluoropropane represented by the chemical formula: CCl ₃ CH ₂ CHClF with anhydrous hydrogen fluoride in the gas phase in the presence of a catalyst. A method for producing a fluorinated propene comprising 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene is provided. The method of the present invention produces a fluorine-containing propene containing 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene by a simple and efficient method that can be applied to an industrial scale. To do.
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Description

  The present invention relates to a method for producing a fluorinated propene containing 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene.

Chemical formula: 2,3,3,3-tetrafluoropropene represented by CF ₃ CF═CH ₂ (HFC-1234yf) and chemical formula: 1,3,3 represented by CF ₃ CH═CHF (HFC-1234ze) , 3-tetrafluoropropene is a compound useful as a refrigerant, and has attracted attention as a constituent component of refrigerants and mixed refrigerants that can be used as alternative chlorofluorocarbons.

Among these compounds, as a method for producing HFC-1234yf, for example, a compound represented by CF ₃ CF ₂ CH ₂ X (X is Cl or I) is reacted in one step with zinc in ethanol. The method is described in Non-Patent Document 1 below. However, since zinc is expensive and has a problem that a large amount of waste is generated, this method is not preferable as an industrial scale production method.

In addition, as a method for producing HFC-1234yf, Patent Document 1 describes a method of reacting chloromethyl tetrafluoropropanoate with an amine, and Patent Document 2 describes 1-trifluoromethyl-1,2, A method by thermal decomposition of 2-trifluorocyclobutane is described, and Patent Document 3 discloses chlorotrifluoroethylene (CClF = CF ₂ ) and methyl fluoride (CH ₃ F) in the presence of a Lewis acid typified by SbF _5. And Patent Document 4 describes a method by thermal decomposition of tetrafluoroethylene (CF ₂ = CF ₂ ) and chloromethane (CH ₃ Cl). Further, Non-patent Documents 2 and 3 below also disclose a method for producing HFC-1234yf.

  However, these methods have problems such as difficulty in obtaining raw materials and difficulty in obtaining them, severe reaction conditions, expensive reaction reagents, low yield, etc. It is hard to say that it is an effective manufacturing method.

On the other hand, as a method for producing HFC-1234ze, CF ₃ CH ₂ CHFX (X is F, Cl, Br or I) is dehydrohalogenated (see Patent Documents 5 to 9, etc.), CF ₃ CHFCH ₂ F (see Patent Document 10 to 11) a method of (HFC-245eb) to the dehydrofluorination, CF ₃ CH = method of fluorinating CHCl (HCFC-1233zd) (Patent Document _{12), CF 3 cHXCH 2 F} ( A method of dehydrohalogenating (X is Cl, Br, or I) is known (Patent Document 13). However, these methods also have problems such as difficulty in the production of raw materials and difficulty in obtaining them, low yields, multi-step processes, etc., and improvements are required as industrial production methods. .

For example, Patent Document _{5, CF 3 CH 2 CHFX (} X is, F, Cl, Br or I) and by dehydrohalogenation describes a process for preparing HFC-1234ze, CF ₃ CH ₂ As a method for producing CHFX, CY ₃ CH ₂ CHY ₂ (Y is F, Cl, Br or I) is reacted with HF (hydrogen fluoride) in the presence of a catalyst such as Cr ₂ O ₃ Is described. However, in order to obtain 1,3,3,3-tetrafluoropropene by this method, a two-step process of reacting with HF (hydrogen fluoride) and dehydrohalogenating is necessary, and the reaction process is It is complicated. Further, as another method for producing CF ₃ CH ₂ CHFX which is an intermediate component of the reaction, a method of reacting CF ₃ X (X is Cl, Br or I) with vinyl fluoride is also described. In this method, since an expensive compound called CF ₃ X is used, it is not an industrially effective production method.

JP 63-2111245 A U.S. Pat. No. 3,996,299 US 2006 / 258891A1 U.S. Pat. No. 2,931,840 US 2005/0245773 A1 US 2008/051611 A1 EP 2000/974571 A2 Japanese Patent Laid-Open No. 11-140002 US 2007/0129579 A1 WO 2008/002499 A2 WO 2008/002500 A1 JP 2007-320896 A WO 2005/108334 A1

J. Chem. Soc., 1957, 2193-2197 J. Chem. Soc., 1970, 3, 414-421 J. Fluorine Chem., 1997, 82, 171-174

  The present invention has been made in view of the above-mentioned problems of the prior art, and its main object is to provide a simple and efficient 2,3,3,3-tetrafluoropropene capable of dealing with an industrial scale. And a method for producing a fluorinated propene comprising 1,3,3,3-tetrafluoropropene.

The inventor has conducted intensive research to achieve the above-described object. As a result, by reacting 1,1,1,3-tetrachloro-3-fluoropropane (HCFC-241fb) with anhydrous hydrogen fluoride in the gas phase in the presence of a catalyst, a one-step reaction operation can be performed. , 3,3,3-tetrafluoropropene (HFC-1234yf) and 1,3,3,3-tetrafluoropropene (HFC-1234ze) can be produced. It has been found that it can be used as an industrially advantageous production method for compounds. The present invention has been completed based on these findings.

That is, the present invention provides a method for producing a fluorinated propene containing the following 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene.
1. Characterized by reacting 1,1,1,3-tetrachloro-3-fluoropropane represented by the chemical formula: CCl ₃ CH ₂ CHClF with anhydrous hydrogen fluoride in the gas phase in the presence of a catalyst. A method for producing a fluorinated propene comprising 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene.
2. Item 2. The method according to Item 1, wherein the catalyst is chromium oxide or fluorinated chromium oxide obtained by fluorinating the chromium oxide.
3. Item 3. The method according to Item 2, wherein the chromium oxide is a compound represented by a composition formula: CrO _m (1.5 <m <3).
4). Item 3. The method according to Item 2, wherein the chromium oxide is a compound having a composition formula: CrO _m within a range of 1.8 ≦ m ≦ 2.5.
5. Item 5. The method according to any one of Items 2 to 4, wherein the chromium oxide further contains at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc, and aluminum.
6). Chromium oxide containing at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc and aluminum was obtained by a method including a step of forming a precipitate from an aqueous solution containing chromium ions and metal ions. 6. The method according to item 5 above.
7). Reaction of anhydrous hydrogen fluoride with 1,1,1,3-tetrachloro-3-fluoropropane in an amount of 3 moles or more per mole of 1,1,1,3-tetrachloro-3-fluoropropane Item 7. The method according to any one of Items 1 to 6 above.
8). Item 8. The method according to any one of Items 1 to 7, wherein 1,1,1,3-tetrachloro-3-fluoropropane is a reaction product of carbon tetrachloride and vinyl fluoride.

  Hereinafter, the production method of the present invention will be specifically described.

Raw material compound In the present invention, as raw materials, 1,1,1,3-tetrachloro-3-fluoropropane (HCFC-241fb) represented by the chemical formula: CCl ₃ CH ₂ CHClF and anhydrous hydrogen fluoride (HF) are used. Use.

  Among the raw materials, 1,1,1,3-tetrachloro-3-fluoropropane is a known substance and can be easily obtained, for example, by reacting carbon tetrachloride with vinyl fluoride. In this method, carbon tetrachloride and vinyl fluoride as raw materials are both relatively inexpensive substances and the manufacturing method is simple. Chloro-3-fluoropropane is a cheaply available material.

  The reaction of carbon tetrachloride and vinyl fluoride to obtain 1,1,1,3-tetrachloro-3-fluoropropane is carried out in the presence of at least one component selected from the group consisting of metals and metal halides. If necessary, the reaction can be carried out using a nonpolar solvent inert to the reaction, for example, a solvent such as methylene chloride or carbon disulfide. Examples of the metal that can be used in this reaction include copper, iron, manganese, and the like, and examples of the metal halide include aluminum chloride, cuprous chloride, cupric chloride, ferric chloride, manganese chloride, and the like. A metal and a metal halide can be used individually by 1 type or in mixture of 2 or more types.

  Further, in the reaction of carbon tetrachloride and vinyl fluoride, a compound containing pentavalent phosphorus as a reaction accelerator, for example, trimethyl phosphate, trimethyl phosphine, triethyl phosphate, triethyl phosphine, tributyl is used as necessary. A phosphate or the like can be used.

  In the said reaction, the usage-amount of vinyl fluoride is about 0.1-10 mol normally with respect to 1 mol of carbon tetrachloride.

  Moreover, about the usage-amount of the at least 1 type of component chosen from the group which consists of a metal and a metal halide, it is about 0.001-2 mol normally with respect to 1 mol of carbon tetrachloride.

  Moreover, the usage-amount of the compound containing pentavalent phosphorus used as a reaction accelerator is about 0.1-10 mol normally with respect to 1 mol of total amounts of a metal and a metal halide.

  The reaction temperature for the reaction between carbon tetrachloride and vinyl fluoride is usually about room temperature to 150 ° C, preferably about 80 to 120 ° C.

  The reaction pressure may be any of normal pressure, pressurization, and depressurization, but can usually be carried out under pressure in a sealed container.

Production method of the present invention In the method of the present invention, 1,1,1,3-tetrachloro-3-fluoropropane represented by the above chemical formula: CCl ₃ CH ₂ CHClF in the gas phase in the presence of a catalyst and of anhydrous hydrogen fluoride by reacting the formula: CF ₃ represented by CF = CH ₂ 2,3,3,3-tetrafluoropropene and formulas: 1,3,3 represented by CF ₃ CH = CHF , Produce fluorine-containing propene including 3-tetrafluoropropene.

As described above, Patent Document 5 describes a method for producing HFC-1234ze by dehydrohalogenation of CF ₃ CH ₂ CHFX (X is F, Cl, Br or I). This method is not an industrially effective production method because the reaction process is complicated and the raw materials used are expensive. Moreover, the only useful substance obtained is HFC-1234ze.

  On the other hand, according to the method of the present invention, 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene are obtained by a substantially one-step reaction using an inexpensive raw material. A fluorine-containing propene containing two kinds of useful compounds called propene can be obtained. For this reason, the method of the present invention is a highly industrially useful method.

Catalyst component The catalyst used in the present invention is not particularly limited, and an effective catalyst for the fluorination reaction with hydrogen fluoride can be used. As such a catalyst, for example, a metal oxide, a metal halide, a transition metal, or the like can be used.

  In the present invention, in particular, when chromium oxide or fluorinated chromium oxide obtained by fluorination of chromium oxide is used as a catalyst, the reaction can proceed efficiently. In this case, as the chromium oxide, in the compound represented by the composition formula: CrOm, m is preferably in the range of 1.5 <m <3, and in the range of 1.8 ≦ m ≦ 2.5. Some are more preferable, and those in the range of 2.0 ≦ m ≦ 2.3 are more preferable. In the above composition formula, if the value of m is too small, the catalytic activity and the selectivity of HFC-1234yf and HFC-1234ze tend to decrease. If the value of m is too large, catalyst deterioration tends to proceed. Neither is preferred. An example of a method for preparing such chromium oxide is as follows.

  First, an aqueous solution of chromium salt (chromium nitrate, chromium chloride, chromium alum, chromium sulfate, etc.) and ammonia water are mixed to obtain chromium hydroxide precipitate. For example, when 1% to 1.2 equivalents of 10% ammonia water is added dropwise to 1 equivalent of chromium nitrate in a 5.7% aqueous solution of chromium nitrate, precipitation of chromium hydroxide occurs. The physical properties of chromium hydroxide can be controlled by the reaction rate of the precipitation reaction at this time. The reaction rate is preferably high, and the catalyst activity can be increased by increasing the reaction rate. Since the reaction rate depends on the reaction solution temperature, the ammonia water mixing method (mixing rate), the stirring state, etc., the reaction rate can be controlled by adjusting these conditions.

This precipitate is washed by filtration and then dried. The drying may be performed, for example, in air at about 70 to 200 ° C., particularly about 120 ° C., for about 1 to 100 hours, particularly about 12 hours. The product at this stage is called the chromium hydroxide state. The product is then disintegrated. At this time, the powder density of the pulverized product (for example, 95% particle size product having a particle size of 1000 μm or less and 46 to 1000 μm) is about 0.6 to 1.1 g / ml, preferably 0.6 to 1.0 g. The precipitation reaction rate is adjusted to about / ml. When the powder density is smaller than 0.6 g / ml, the strength of the pellet is insufficient, which is not preferable. On the other hand, if the powder density is larger than 1.1 g / ml, the activity of the catalyst is low and the pellets are easily broken, which is not preferable. The specific surface area of the powder is preferably about 100 m ² / g or more, more preferably about 120 m ² / g or more, at 200 ° C. for 80 minutes under degassing conditions. The upper limit of the specific surface area is, for example, about 220 m ² / g. In the present specification, the specific surface area is a value measured by the BET method.

If necessary, about 3 wt% or less of graphite is mixed into the chromium hydroxide powder, and pellets are formed by a tableting machine. For example, the pellet may have a diameter of about 3.0 mm and a height of about 3.0 mm. The crushing strength (pellet strength) of the pellet is preferably about 210 ± 40 kg / cm ² . If the crushing strength is too high, the gas contact efficiency is lowered, the catalytic activity is lowered, and the pellets are easily cracked. On the other hand, if it is too small, the pellets are easily pulverized and difficult to handle.

  The formed pellets are fired in an inert atmosphere, for example, in a nitrogen stream to form amorphous chromium oxide. The firing temperature is preferably 360 ° C. or higher. However, since the crystallization occurs when the temperature becomes too high, it is desirable that the firing temperature be as high as possible within a range where this can be avoided. For example, it may be fired at about 380 to 460 ° C., particularly about 400 ° C., for about 1 to 5 hours, particularly about 2 hours.

The specific surface area of the baked chromium oxide is about 170 m ² / g or more, preferably about 180 m ² / g or more, more preferably about 200 m ² / g or more. The upper limit of the specific surface area is generally about 240 m ² / g, preferably about 220 m ² / g. When the specific surface area exceeds 240 m ² / g, the activity is high but the deterioration rate increases, and when the specific surface area is smaller than 170 m ² / g, the activity of the catalyst becomes low, which is not preferable.

  The fluorinated chromium oxide can be prepared by the method described in JP-A-5-146680. For example, it can be obtained by fluorination (HF treatment) of chromium oxide obtained by the above-described method with hydrogen fluoride. The temperature of fluorination may be a temperature at which generated water does not condense (for example, about 150 ° C. at 0.1 MPa), and the upper limit may be a temperature at which the catalyst does not crystallize due to heat of reaction. Although there is no restriction | limiting in the pressure at the time of fluorination, It is preferable to carry out by the pressure when it uses for a catalytic reaction. The temperature of fluorination is, for example, about 100 to 460 ° C.

The surface area of the catalyst is reduced by the fluorination treatment, but generally the higher the specific surface area, the higher the activity. The specific surface area of at fluorinated phase is preferably about 25~130m ² / g, but more preferably about 40 to 100 m ² / g, but is not limited to this range.

  The fluorination reaction of chromium oxide may be performed by supplying hydrogen fluoride to a reactor filled with chromium oxide prior to the execution of the method of the present invention described later. After fluorination of chromium oxide by this method, by supplying 1,1,1,3-tetrachloro-3-fluoropropane as a raw material to the reactor, 2,3,3,3-tetrafluoropropene and The formation reaction of 1,3,3,3-tetrafluoropropene can proceed.

  Although the degree of fluorination is not particularly limited, for example, fluorinated chromium oxide having a fluorine content of about 10 to 30% by weight can be suitably used.

  Further, in the present invention, a chromium-based catalyst described in JP-A-11-171806 (hereinafter sometimes referred to as “metal component-added chromium catalyst”) is used as a chromium oxide catalyst or a fluorinated chromium oxide catalyst. be able to. This chromium-based catalyst is in an amorphous state, and is mainly composed of a chromium compound to which at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc and aluminum is added. The average valence number of chromium in the compound is +3.5 or more and +5.0 or less.

  The method for producing the metal component-added chromium catalyst is not particularly limited. After obtaining the chromium oxide catalyst by the above-described method, the catalyst is impregnated with the above-described aqueous solution containing the metal element, and then calcined. A metal component-added chromium catalyst can be obtained. In particular, in the process of preparing a chromium oxide catalyst by the above-described method, a compound containing the above metal element is added to an aqueous solution of a chromium salt to add chromium ions and metals. It is preferable to prepare an aqueous solution containing ions, add aqueous ammonia to the aqueous solution to form a precipitate containing chromium hydroxide and a metal component, and then dry and fire according to the method described above. When using the metal component-added chromium catalyst obtained by this method, the desired 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene can be obtained with high selectivity. In particular, the selectivity of 1,3,3,3-tetrafluoropropene can be greatly improved.

  The compound containing at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc, and aluminum may be any compound that is soluble in an aqueous solution containing a chromium salt, such as a halide or nitrate. Water-soluble compounds such as sulfates can be used. The amount of these metal elements added is preferably such that the metal element amount is about 0.1 to 50 wt%, based on the total amount of the metal component-added chromium catalyst finally obtained, and about 1.0 to 30 wt%. More preferably, the amount is

  The metal component-added chromium catalyst thus obtained may be further subjected to fluorination treatment in the same manner as described above.

  The various catalysts described above can also be used by being supported on a carrier such as alumina or activated carbon.

Reaction Method In the method of the present invention, usually, 1,1,1,3-tetrachloro-3-fluoropropane and anhydrous hydrogen fluoride as raw materials are supplied in a gas phase state to a reactor filled with the above-described catalyst. That's fine. As a result, 2,3,3,3-tetrafluoropropene (HFC-1234yf) and 1,3,3,3-tetrafluoropropene (E-HFC-1234ze + Z-HFC-1234ze ) Containing the reaction product can be obtained.

  In the present invention, the ratio of 1,1,1,3-tetrachloro-3-fluoropropane and anhydrous hydrogen fluoride used as a raw material is not particularly limited, but for example, 1,1,1,3-tetra 3 mol or more of hydrogen fluoride may be used with respect to 1 mol of chloro-3-fluoropropane, and 5 mol or more of hydrogen fluoride is preferably used. The upper limit of the supply amount of hydrogen fluoride is preferably about 20 moles, more preferably about 15 moles per mole of 1,1,1,3-tetrachloro-3-fluoropropane.

  By using anhydrous hydrogen fluoride within the above range, both the conversion rate and catalytic activity of HCFC-241fb can be maintained well. In contrast, if the amount of hydrogen fluoride supplied is too small, 2,3,3,3-tetrafluoropropene (HFC-1234yf) and 1,3,3,3-tetrafluoropropene (E-HFC-1234ze + Z-HFC-1234ze) is not preferable because the selectivity is reduced. Moreover, even if the supply amount of hydrogen fluoride increases too much, the effect is not particularly improved, which is uneconomical.

  The above raw materials may be supplied to the reactor as they are, or may be supplied after being diluted with an inert gas such as nitrogen, helium, or argon.

  In order to maintain the catalytic activity for a long time, oxygen may be accompanied to the raw material and supplied to the reactor. In this case, the supply amount of oxygen is preferably about 0.1 to 5 mol% based on the total number of moles of 1,1,1,3-tetrachloro-3-fluoropropane and anhydrous hydrogen fluoride.

  The form of the reactor used in the method of the present invention is not particularly limited, and for example, an adiabatic reactor filled with a catalyst, a multi-tube reactor removed with a heat medium, or the like can be used. As the reactor, it is preferable to use a reactor made of a material resistant to the corrosive action of hydrogen fluoride, such as HASTALLOY, INCONEL, and MONEL.

  In the method of the present invention, the reaction temperature is preferably about 170 to 450 ° C, more preferably about 210 to 400 ° C, as the temperature in the reactor. When the temperature is higher than this temperature range, the activity of the catalyst is lowered. Conversely, when the temperature is lowered, the raw material conversion rate and the selectivity for 1,3,3,3-tetrafluoropropene are lowered, which is not preferable.

  About the pressure at the time of reaction, it does not specifically limit, Reaction can be performed under a normal pressure or pressurization. That is, the reaction in the present invention can be carried out under atmospheric pressure (0.1 MPa), but may be carried out under a pressure up to about 1.0 MPa.

The reaction time is not particularly limited, but the ratio of the catalyst filling amount W (g) to the total flow rate Fo (flow rate at 0 ° C., 0.1 MPa: cc / sec) of the raw material gas flowing into the reaction system is usually W / The contact time represented by Fo may be in the range of 2 to 30 g · sec / cc, preferably about 4 to 15 g · sec / cc. The total flow rate Fo is the flow rate of 1,1,1,2-tetrachloro-3-fluoropropane and anhydrous hydrogen fluoride supplied as raw materials, or when supplying an inert gas and / or an oxidizing gas. The above-mentioned raw material gases and the flow rates of these gases are combined.
At the reactor outlet, a reaction product containing 2,3,3,3-tetrafluoropropene (HFC-1234yf) and 1,3,3,3-tetrafluoropropene (E-HFC-1234ze + Z-HFC-1234ze) You can get things. 1,3,3,3-tetrafluoropropene is obtained as a mixture of E-form and Z-form.

  Within the above reaction conditions, 2,3,3,3-tetrafluoropropene (HFC-1234yf) exhibits a selectivity of about 2 to 5%, and 1,3,3,3-tetrafluoropropene ( E-HFC-1234ze + Z-HFC-1234ze) can increase the selectivity up to 25% or more by selecting the reaction conditions and the catalyst to be used.

The reaction product may be used as it is, or 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene may be recovered separately by separation and purification by distillation or the like. good. Other fluorine-containing olefins may be converted to other compounds in the next reaction step. Further, when there is unreacted CCl ₃ CH ₂ CHClF (HCFC-241fb), it can be returned to the reactor again after separation and purification and used as a raw material. Since unreacted raw materials can be recycled in this way, high productivity can be maintained even when the raw material conversion rate is low.

  According to the method of the present invention, 1,1,1,3-tetrachloro-3-fluoropropane and hydrogen fluoride, which are easily available, are used as raw materials, and the desired 2,3,3, A fluorine-containing propene containing 3-tetrafluoropropene (HFC-1234yf) and 1,3,3,3-tetrafluoropropene (E-HFC-1234ze + Z-HFC-1234ze) can be obtained.

Hereinafter, the present invention will be described in more detail with reference to production examples of 1,1,1,3-tetrachloro-3-fluoropropane (HCFC-241fb) used as a raw material and examples of the present invention.

Production Example 1
1,1,1,3-Tetrachloro-3-fluoropropane (HCFC-241fb) synthesis thermometer, vacuum line, nitrogen purge line, preparation line, gauge and pressure relief valve installed in a 1000ml autoclave with soft iron powder 4 0.5 g (79.2 mmol), triethyl phosphate 20 g (79.2 mmol), ferric chloride 100 mg, and carbon tetrachloride 420 g (2.73 mol) were charged and purged 5 times with nitrogen and once with vinyl fluoride. Next, the inside of the autoclave was evacuated and charged with vinyl fluoride until the gauge pressure became 0.4 MPa while stirring. The reaction started when heated to 120 ° C., the internal temperature increased to 127 ° C., and the pressure decreased from 0.9 MPa to 0.4 MPa. While maintaining the vinyl fluoride pressure at 0.8 MPa, the mixture was stirred at an internal temperature of 120 ° C. for 8 hours. Thereafter, 10 g (39.6 mmol) of triethyl phosphate was injected into the autoclave and further reacted at 120 ° C. for 10 hours.

  After completion of the reaction, the crude product was analyzed by gas chromatography to confirm that carbon tetrachloride was completely consumed. After washing twice with three times the amount of the crude product, the organic layer was dried over magnesium sulfate to obtain HCFC-241fb having a gas chromatography purity of 88.9%. The by-products were ethylene and vinyl fluoride oligomer. The obtained crude product was distilled under reduced pressure (10 mmHg) to collect a fraction of 63 to 65 ° C., thereby obtaining 467 g (2.35 mol, yield 86%) of HCFC-241fb having a purity of 98% or more.

Example 1
42.7 g of a catalyst obtained by subjecting chromium oxide having a composition of CrO _2.0 to fluorination treatment (fluorine content: about 16.4% by weight) was charged into a tubular Hastelloy reactor having an inner diameter of 20 mm and a length of 1 m.

This reaction tube is maintained at atmospheric pressure (0.1 MPa) and 250 ° C., anhydrous hydrogen fluoride (HF) is 300 cc / min (flow rate at 0 ° C. and 0.1 MPa), and nitrogen (N ₂ ) is 100 cc / min. (0 ° C, flow rate at 0.1 MPa) was fed to the reactor and maintained for 2 hours. After that, supply of nitrogen (N ₂ ) was stopped and 1,1,1,3-tetrachloro-3-fluoropropane (HCFC-241fb, purity 98.9%) was 20cc / min (flow rate at 0 ° C, 0.1MPa) The temperature of the reactor was changed to 281 ° C. The molar ratio of hydrogen fluoride (HF) to 1,1,1,3-tetrachloro-3-fluoropropane was 15, and the contact time (W / F ₀ ) was 8.0 g · sec / cc. Two hours after the target reaction temperature was reached, the outflow gas from the reactor was analyzed using a gas chromatograph. The results are shown in Table 1.

The structure of each product is as follows:
CF ₃ CF = CH ₂ (HFC-1234yf)
CF ₃ CH = CHF (E-HFC-1234ze + Z-HFC-1234ze)
CF ₃ CF ₂ CH ₃ (HFC-245cb)
CF ₃ CH ₂ CHF ₂ (HFC-245fa)
CF ₃ CCl = CH ₂ (HCFC-1233xf)
CF ₃ CH = CHCl (E-HCFC-1233zd + Z-HCFC-1233zd)
CF ₃ CH = CH ₂ (HFC-1243zf)
CF ₃ CH ₂ CHCl ₂ (HCFC-243fa)
Example 2
The experiment was performed under the same conditions as in Example 1 except that 42.7 g of a catalyst obtained by subjecting chromium oxide having a composition of CrO _2.2 to fluorination treatment (fluorine content: about 17.8% by weight) was used. The molar ratio of HF to 1,1,1,3-tetrachloro-3-fluoropropane was 15, and the contact time (W / F ₀ ) was 8.0 g · sec / cc. The analysis results are shown in Table 1.

Example 3
Using 36.7g of the catalyst obtained by fluorination treatment of chromium oxide composed of CrO _1.9 , change the flow rate of anhydrous hydrogen fluoride to 200 cc / min (flow rate at 0 ° C, 0.1 MPa), The experiment was performed under the same conditions as in Example 1 except that the reaction temperature was changed to 300 ° C. The molar ratio of HF to 1,1,1,3-tetrachloro-3-fluoropropane was 10, and the contact time (W / F ₀ ) was 10.0 g · sec / cc. The analysis results are shown in Table 1.

Example 4
The same catalyst as that used in Example 1 was used, the catalyst amount was changed to 35.0 g, the flow rate of anhydrous hydrogen fluoride was changed to 400 cc / min (flow rate at 0 ° C. and 0.1 MPa), and the reaction temperature was changed to 380 ° C. The experiment was performed under the same conditions as in Example 1 except for the above. The molar ratio of HF to 1,1,1,3-tetrachloro-3-fluoropropane was 20, and the contact time (W / F ₀ ) was 5.0 g · sec / cc. The analysis results are shown in Table 1.

Example 5
The experiment was performed under the same conditions as in Example 1 except that 42.7 g of a catalyst obtained by subjecting chromium oxide having a composition of CrO _1.6 to a fluorination treatment (fluorine content: about 13.9% by weight) was used. The molar ratio of HF to 1,1,1,3-tetrachloro-3-fluoropropane was 15, and the contact time (W / F ₀ ) was 8.0 g · sec / cc. The analysis results are shown in Table 1.

Example 6
(1) Catalyst preparation step 221.4 g (0.549 mol) of chromium nitrate nonahydrate and 41.4 g (0.137 mol) of nickel nitrate hexahydrate were dissolved in pure water to obtain a mixed solution having a total weight of 2710 g. While maintaining the temperature of this mixed solution at 50 ° C., 402 g of 10 wt% aqueous ammonia was added dropwise with stirring to obtain a precipitate of chromium hydroxide containing nickel. Next, this was filtered off, and after washing with pure water, a portion of the solid chromium hydroxide obtained by drying at 120 ° C. for 12 hours in air was pulverized to a particle size of 0.2 mm or less, and powdered 63.4 g of chromium hydroxide was obtained.

Next, a powder obtained by adding 2.5% by weight of graphite to this and mixing it was compressed into a cylindrical pellet having a diameter of 3 mm and a height of 3 mm, and calcined at 400 ° C. for 2 hours in a nitrogen gas stream. g was obtained. The valence number of Cr in this nickel-containing chromium oxide was CrO _2.0 from the value specified from the magnetic susceptibility measurement. Further, from the X-ray diffraction measurement (XRD), it was confirmed that this catalyst was amorphous, and the specific surface area was 187.1 m ² / g.

  The weight ratio of the metal contained in the catalyst was determined from the measurement result of the obtained catalyst by SEM (electron microscope), and was found to be Ni: Cr = 20.2: 79.8.

(2) Reaction process A tubular Hastelloy reactor with an inner diameter of 20 mm and a length of 1 m was obtained by subjecting the catalyst prepared in the above step (1) to fluorination treatment with 36.7 g (fluorine content of about 15.1 wt%). Filled.
The reaction tube is maintained at atmospheric pressure (0.1 MPa) and 250 ° C., anhydrous hydrogen fluoride (HF) is 200 cc / min (0 ° C., flow rate at 0.1 MPa), and nitrogen (N ₂ ) is 100 cc / min ( At 0 ° C. and a flow rate of 0.1 MPa) and maintained for 2 hours. After that, supply of nitrogen (N ₂ ) was stopped and 1,1,1,3-tetrachloro-3-fluoropropane (HCFC-241fb, purity 98.9%) was 20cc / min (flow rate at 0 ° C, 0.1MPa) The temperature of the reactor was changed to 300 ° C. The molar ratio of HF to 1,1,1,3-tetrachloro-3-fluoropropane was 10, and the contact time (W / F ₀ ) was 10.0 g · sec / cc. The gas effluent from the reactor 3 hours after the target reaction temperature was reached was analyzed using a gas chromatograph. The results are shown in Table 1.

Claims (8)

Characterized by reacting 1,1,1,3-tetrachloro-3-fluoropropane represented by the chemical formula: CCl ₃ CH ₂ CHClF with anhydrous hydrogen fluoride in the gas phase in the presence of a catalyst. A method for producing a fluorinated propene comprising 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene. The method according to claim 1, wherein the catalyst is chromium oxide or fluorinated chromium oxide obtained by fluorinating the chromium oxide. The method according to claim 2, wherein the chromium oxide is a compound represented by a composition formula: CrO _m (1.5 <m <3). The method according to claim 2, wherein the chromium oxide is a compound having a composition formula: CrO _m within a range of 1.8 ≦ m ≦ 2.5. The method according to any one of claims 2 to 4, wherein the chromium oxide further contains at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc and aluminum. Chromium oxide containing at least one metal element selected from the group consisting of indium, gallium, cobalt, nickel, zinc and aluminum was obtained by a method including a step of forming a precipitate from an aqueous solution containing chromium ions and metal ions. The method according to claim 5, wherein The method according to any one of claims 1 to 6, wherein 3 moles or more of anhydrous hydrogen fluoride is reacted with 1 mole of 1,1,1,3-tetrachloro-3-fluoropropane. The method according to any one of claims 1 to 7, wherein 1,1,1,3-tetrachloro-3-fluoropropane is a reaction product of carbon tetrachloride and vinyl fluoride.