JP2533596B2 - Hydrogen peroxide production method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing hydrogen peroxide, which comprises reacting hydrogen and oxygen in a solvent in the presence of a catalyst.

Problems to be Solved by the Related Art and Invention Presently, the main method of industrially producing hydrogen peroxide is a method of continuously performing oxidation and reduction using anthraquinones as a medium.

 The drawbacks of this method are as follows.

Numerous reactors for reduction, oxidation, extraction etc. are required.

It is necessary to circulate a large amount of anthraquinone solution.

 Anthraquinones are decomposed and lost.

Therefore, if hydrogen and oxygen can be directly reacted to efficiently produce hydrogen peroxide, it is not necessary to use anthraquinones as a medium, and the above-mentioned problems with the existing hydrogen peroxide production method are eliminated.

Some proposals have already been made for a method for directly producing hydrogen peroxide from hydrogen and oxygen in the presence of a platinum group catalyst (Japanese Patent Laid-Open Nos. 14539/50, 4097/51, and 51/97/95). 1
24698, JP-A-52-109493). These proposals have not reached a level that can withstand industrial operation in terms of the accumulation rate and production rate of hydrogen peroxide.

An object of the present invention is to provide a method for efficiently producing hydrogen peroxide by directly reacting hydrogen and oxygen.

Means and Actions for Solving the Problems The present inventor has conducted extensive studies on a method for directly producing hydrogen peroxide from hydrogen and oxygen, and as a result, the object of the present invention was achieved by using a specific catalyst in a specific solvent. The present invention has been completed and the present invention has been completed.

That is, the present invention comprises: (1) reacting hydrogen and oxygen in the presence of a catalyst having a metal supported on a hydrophobic carrier in a solvent composed of a fluorine-containing compound that forms a two-liquid phase with water; A method of producing hydrogen oxide, comprising: (2) hydrogen and oxygen in the presence of a catalyst having a metal supported on a hydrophobic carrier in a solvent consisting of water and a fluorine-containing compound forming a two-liquid phase. Is a method for producing hydrogen peroxide, in which hydrogen peroxide is allowed to react and the hydrogen peroxide is concentrated and separated in the aqueous phase.

The fluorine-containing compound that forms a two-liquid phase with water used in the method of the present invention usually has a higher solubility of gas such as oxygen or hydrogen than water. Therefore, in the case of the reaction of hydrogen and oxygen using a fluorine-containing compound as a solvent,
The reaction rate can be kept high as compared with the case of the reaction between hydrogen and oxygen which is carried out using an ordinary water solvent.

The type of fluorine-containing compound is not particularly limited, but C ₂ F ₄ Cl
₂ , C ₂ F ₄ Br ₂ , C ₅ F ₁₁ OH, C ₆ F ₁₄ , C ₅ F ₁₀ O, C ₁₀ F ₁₈ , and (C
₄ F ₉ ) ₃ N etc. are often used.

The catalyst used in the method of the present invention is a hydrophobic catalyst, and a hydrophobic carrier on which a metal component is supported is often used. As a hydrophobic carrier, polytetrafluoroethylene, polyethylene, polystyrene, a resin such as silicon-containing resin or fluorinated graphite that itself exhibits hydrophobicity, or silica, alumina, activated carbon itself such as hydrophilic, The one whose surface is treated with a coating agent such as Teflon (trade name) or fluorinated graphite to make it hydrophobic is used. Similarly, a catalyst obtained by treating the surface of a catalyst in which a metal is supported on a hydrophilic carrier with a coating agent such as Teflon (trade name) or fluorinated graphite to impart hydrophobicity can also be used.

As the catalytic metal supported on the support, a metal capable of activating oxygen and / or hydrogen is used. As a specific example, platinum group elements, nickel, and the like are frequently used, and palladium is usually suitable. The amount of metal component supported is in the range of 0.1 to 5 wt%.

The conditions for adjusting the catalyst are not particularly limited, and the conditions frequently used are sufficient. Especially, the condition for imparting hydrophobicity is a necessary condition.

In the reaction, the composition ratio of hydrogen and oxygen can be arbitrarily selected. The reaction can be carried out in a wide range from a pressure lower than atmospheric pressure to a pressure, but a range of atmospheric pressure to 20 kg / cm ² is suitable.

The reaction temperature is preferably 60 ° C or lower, particularly preferably 40 ° C or lower, and the reaction is usually carried out at 0 to 30 ° C.

The mixing ratio of the fluorine-containing compound and water when used by mixing or suspending the fluorine-containing compound and water forming a two-liquid phase with water is not particularly limited, but the volume of the fluorine-containing compound and water is 100. : It is in the range of 50 to 1.

Explaining the case where the reaction is carried out in a batch system as an example, 0.5 to 10 wt% of a catalyst is added to a fluorine-containing compound, and hydrogen and oxygen are blown to react.

 The time required for the reaction is 0.5 to 10 hours.

When a mixture of a fluorine-containing compound and water is used as a solvent, it is separated into two phases after the reaction, concentrated hydrogen peroxide is obtained in the aqueous phase, and if necessary, further concentrated by a conventional method such as distillation. To do. In this case, since the hydrogen peroxide concentrated in the aqueous phase has a low probability of coming into contact with the catalyst, it is considered that catalytic decomposition of the concentrated hydrogen peroxide can be prevented.

Examples Hereinafter, the present invention will be described with reference to examples.

Example 1 100 g of a fluorine-containing compound [C ₂ F ₁₀ O] as a solvent was charged into a 1-inch stainless steel column having an inner surface coated with Teflon, and hydrogen gas of 100 ml / min and oxygen gas of 600 ml / min were blown from the bottom to carry out the reaction. The reaction was carried out at a pressure of 6 kg / cm ² .

In the solvent, Teflon (trade name) carrier (particle size 100 to 500
μ) was suspended 5 g of a catalyst carrying 0.8 wt% of Pd,
The reaction temperature was maintained at 15 to 18 ° C by cooling the outside of the column with water. After 6 hours from the start of the reaction, 7.5 wt% of hydrogen peroxide was produced in the solvent.

Example 2 100 g of perfluorodecalin [C ₁₀ F ₁₈ ] was used as a solvent, and the reaction was carried out using the apparatus of Example 1. As a catalyst, 8 g of a catalyst in which 0.5 wt% of Pd was carried on Nafion (trade name, particle diameter 0.1 to 0.5 mm) manufactured by DuPont was charged. As a result of reacting in the same manner as in Example 1, hydrogen peroxide was 8.7 w in the solvent.
t% produced.

Example 3 Perfluorotributylamine [(C ₄ F ₉ ) as a solvent
₃ N] 100 g and water 30 g were mixed and suspended. 6g of catalyst that made 1wt% Pd supported on silica gel a hydrophobic surface by treating with polytetrafluoroethylene emulsion
(Particle size 100 to 300 μ) was charged and reacted in the same manner as in Example 1. After reacting for 5 hours, the reaction solution was separated, and the concentration of hydrogen peroxide extracted and concentrated in the aqueous phase was 15 wt%.

Comparative Example 1 Perfluorotributylamine [C ₄ F ₉ ) as a solvent
₃ N] 100 g and 30 g of water were mixed and suspended, and 6 g of a catalyst supporting Pd on 1 wt% of Pd (not subjected to hydrophobic treatment) was charged in silica gel powder, and peroxidized under the same reaction conditions as in Example 3. Hydrogen synthesis was performed. After the catalyst was filtered off, the reaction solution was separated, and the concentration of the hydrogen peroxide extracted and concentrated in the aqueous phase was analyzed and the result was 2.1 wt%.

That is, when a hydrophilic catalyst is used, the amount of hydrogen peroxide produced is significantly lower than when a hydrophobic catalyst is used.

Effects of the Invention According to the method of the present invention, hydrogen and oxygen can be catalytically reacted, and hydrogen peroxide can be efficiently produced by a single-step reaction operation.

Claims (3)

(57) [Claims] 1. A method for producing hydrogen peroxide, which comprises reacting hydrogen with oxygen in the presence of a catalyst comprising a metal and a hydrophobic carrier supported in a solvent comprising a fluorine-containing compound forming a two-liquid phase with water. Law. 2. Hydrogen and oxygen are reacted in the presence of a catalyst having a metal supported on a hydrophobic carrier in a solvent consisting of water and a fluorine-containing compound that forms a two-liquid phase with water, and an aqueous phase is obtained. A method for producing hydrogen peroxide in which hydrogen peroxide is concentrated and separated. 3. The method for producing hydrogen peroxide according to claim 1 or 2, wherein the catalyst is obtained by treating a hydrophilic catalyst with a hydrophobic compound.