JPH01319440A - Method for producing 1,1-dichloro-2,2,2-trifluoroethane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Fields] The present invention is applicable to refrigerants, blowing agents, solvents, raw materials for trifluoroacetic acid, and Freon 124 (1-chloro-1,2°2.2-
The present invention relates to a method for producing 1,1-dichloro-2,2,2-trifluoroethane (Freon 123), which is a compound useful as a raw material for tetrafluoroethane) and the like.

[Prior art and problems] Reducing 1,1.1-trichloro-2,2', 2-)lifluoroethane to 1,1-dichloro-2,2,2-
A known method for producing trifluoroethane is to produce trifluoroethane in a protic solvent using zinc as a reducing agent. (See Japanese Patent Application Laid-Open No. 58-222038) However, there are problems such as processing of zinc chloride, which is a by-product, and it is not suitable for mass production.

[Means for Solving the Problems] As a method for reducing chlorofluoroethane continuously and in large amounts, there is a method of reducing it with hydrogen in the presence of a reduction catalyst. This method? R-113a (1
, 1,1-trichloro-2,2,2-trifluoroethane) by reduction of R-123 (1,1-dichloro-2,
It has been found that when used in the production of 2,2-trifluoroethane), there are two problems as shown below. The first is the acid resistance of the catalyst.

That is, in this reaction, hydrogen chloride is produced as a by-product as shown in the formula below. Therefore, it is necessary to use a catalyst that has acid resistance. Basically, for example, a platinum group element, or an alloy consisting mainly of a platinum group element and an iron group element or rhenium is used as a hydrogenation catalyst. This can be done by using

The second point is the improvement of reaction selectivity.The present reaction is a sequential reaction.For example, when palladium, which is a typical reduction catalyst, is used, R-123 is further reduced and R-1
It was found that 33a and R-143a were produced in large quantities. Furthermore, it has been found that when ruthenium, which is the cheapest among the platinum group elements, is used, although the reaction selectivity is very excellent, the reaction activity is not necessarily sufficient. Furthermore, since ruthenium has poor corrosion resistance among the platinum group metals, it is considered that it is not necessarily suitable for systems that generate hydrogen chloride, such as in this reaction.

Therefore, ruthenium has an element with better acid resistance,
Alternatively, it is believed that by adding an element with more excellent hydrogenation activity, a catalyst with excellent reactivity and selectivity and long life can be obtained. As a result of intensive studies on optimizing the composition, preparation conditions, and reaction conditions of the ruthenium alloy catalyst, we found that 1.1.1-trichloro-2,2,2-1-lifluoroethane in the presence of the present ruthenium alloy catalyst. The inventors have discovered that R-123 can be obtained with extremely high efficiency by reducing a raw material with hydrogen, and have come to provide the present invention.

Hereinafter, details of the present invention will be explained together with examples.

It is generally said that in alloy catalysts, the characteristics of the component elements appear depending on the alloy composition, and the amount of added components is 0.01 to 90% by weight, especially 0.1 to 60% by weight. This is suitable because it takes advantage of the properties of ruthenium.

In the present invention, suitable carriers for the alloy catalyst include activated carbon, alumina, zirconia, and the like.

In addition, upon use, such metal compounds are at least partially reduced.

R-113a (1,1,1-trichloro-2.2.2
-trifluoroethane) in the reduction reaction, the proportions of hydrogen and raw materials can be varied considerably. However, stoichiometric amounts of hydrogen are usually used to remove the halogen atoms. Significantly more than stoichiometric amounts of hydrogen can be used, for example 4 moles or more, based on the total number of moles of starting materials.

As for the reaction pressure, normal pressure or a pressure higher than normal pressure can be used.

The reaction temperature is 0°C to 450°C, preferably 50°C to 300°C.
It is appropriate to carry out the reaction in a liquid phase or a gas phase.

The contact time is usually 0.1 to 0.1 when the reaction is carried out in the gas phase.
300 seconds, especially 5 to 30 seconds.

[Example code] Examples of the present invention are shown below.

Example 1 Activated carbon was immersed in pure water to impregnate the inside of the pores with water.

After adjusting the pH using hydrochloric acid, add a small amount of an aqueous solution in which ruthenium chloride and palladium chloride are dissolved in a ratio of 50:50 by weight of the metal components, and only 0.5% of the total weight of the metal components based on the weight of activated carbon. The ionic components were adsorbed onto the activated carbon. After washing with pure water, it was heated to 150
After drying at 550° C. for 4 hours in nitrogen, hydrogen was introduced and the mixture was kept at 300° C. for 5 hours for reduction.

Filled with 300cc of this catalyst, the inner diameter is 2.6cm and the length is 1.
A 00 cm Inconel 600 reaction tube was immersed in a salt bath furnace.

Hydrogen and 1.1.1-trichloro-2.2.2-trifluoroethane were introduced into the reaction tube in a molar ratio of 1:1.

The flow rates of hydrogen and starting material were 100 cc/min and 1
The reaction temperature was 120"C. Gas chromatography was used to analyze the produced gas. The results are shown in Table 1, No. 1.

Example 2 Ruthenium chloride and chloroplatinic acid at a metal component weight ratio of 50
: A catalyst was prepared in the same manner as in Example 1, except that a ratio of 50% was used, and a reaction was carried out. The results are shown in Table 1 No. 2.

Example 3 Ruthenium chloride and rhodium chloride in a metal component weight ratio of 4
A catalyst was prepared and a reaction was carried out in the same manner as in Example 1, except that a ratio of 0:60 was used. The results are shown in Table 1 N003.

Example 4 A catalyst was prepared and a reaction was carried out in the same manner as in Example 1, except that ruthenium chloride and iridium chloride were used in a weight ratio of 50:50 as metal components. The results are shown in Table 1 N094.

Example 5 A catalyst was prepared and a reaction was carried out in the same manner as in Example 1, except that ruthenium chloride and potassium perrhenate were used in a metal component weight ratio of 60+40, and the reduction temperature was 500°C. The results are shown in Table 1, No. 5.

Comparative Example 1 Coconut shell activated carbon was immersed in pure water to impregnate the inside of the pores with water. An aqueous solution in which palladium chloride was dissolved in an amount of 0.5% of the total weight of the metal components based on the weight of the activated carbon was added little by little to make the ionic components adsorbed onto the activated carbon. After washing with pure water, it was dried at 150"C for 5 hours.
Next, after drying in nitrogen at 550°C for 4 hours, hydrogen was introduced and the mixture was maintained at 300°C for 5 hours for reduction. Using this catalyst, a reaction was carried out in the same manner as in Example 1, and the reaction was analyzed. The results are shown in Table 1 N006.

Comparative Example 2 Coconut shell activated carbon was immersed in pure water to impregnate the inside of the pores with water. An aqueous solution in which ruthenium chloride was dissolved in an amount of 0.5% of the total weight of the metal components based on the weight of the activated carbon was added little by little to cause the ionic components to be adsorbed onto the activated carbon. After washing with pure water, it was dried at 150 °C for 5 hours. Then, after drying in nitrogen at 550 °C for 4 hours, hydrogen was introduced,
The mixture was maintained at 300° C. for 5 hours for reduction. Using this catalyst, a reaction was carried out in the same manner as in Example 1, and the reaction was analyzed. The results are shown in Table 1 No. 7.

Table 1 Contact time: 20 seconds However, 113a: 1,1.1-)dichloro-2,2,2-trifluoroethane 123: 1.1-dichloro-2
,2,2-)lifluoroethane 133a:1-chloro-
2,2,2-trifluoroethane 143a:1,1.1
-Trifluoroethane [Effects of the Invention] As shown in Examples, the present invention has excellent effects in improving reaction activity and selectivity.

Claims (1)

[Claims] 1,1,1,1-trichloro-2,2,2-trifluoroethane raw material is mixed with ruthenium and one or more selected from platinum, rhodium, iridium, palladium, and rhenium. 1,1- characterized by being reduced by hydrogen in the presence of a hydrogenation catalyst comprising a metal added
Method for producing dichloro-2,2,2-trifluoroethane. 2,1,1,1-trichloro-2,2,2-trifluoroethane using at least a stoichiometric amount of hydrogen relative to the 2,1,1,1-trichloro-2,2,2-trifluoroethane feedstock The manufacturing method according to claim 1, wherein one chlorine atom in the ethane raw material is removed. 3. The manufacturing method according to claim 1 or 2, which uses a ruthenium alloy catalyst having an additive component concentration of 0.01 to 90% by weight, preferably 0.1 to 60% by weight. 4. Ruthenium and one or two selected from platinum, rhodium, iridium, palladium, and rhenium
Claims 1 to 3 use a hydrogenation catalyst in which a catalyst to which more than one element is added is supported on an activated carbon carrier.
The manufacturing method according to any one of paragraph 3. 5. Ruthenium and one or two selected from platinum, rhodium, iridium, palladium and rhenium
4. The production method according to any one of claims 1 to 3, which uses a hydrogenation catalyst in which a catalyst including at least one metal is supported on an alumina carrier. 6. Ruthenium and any one or two selected from platinum, rhodium, iridium, palladium and rhenium
Claim 1 uses a hydrogenation catalyst in which a catalyst to which more than one metal is added is supported on a zirconia carrier.
The manufacturing method according to any one of Items 1 to 3. 7. The method according to any one of claims 1 to 6, wherein the reaction is carried out in a liquid phase or in a gas phase at a temperature range of 0°C to 450°C, preferably 50°C to 300°C. Production method.