JPH0272132A - Production of phenol - Google Patents

Abstract

PURPOSE:To obtain phenol from raw material of low cost with one process in high yield by contact reacting in vapor phase of benzene, hydrogen chloride and oxygen in the presence of catalyst. CONSTITUTION:Benzene, hydrogen chloride, preferably aqueous solution of hydrochloric acid and oxygen are subjected to contact reaction in vapor phase in the presence of a catalyst having both functions of oxychlorinating function and hydrolyzing function such as copper phosphate, chromium phosphate or iron phosphate and preferably in the co-existence of water, usually in an atmosphere of oxygen or oxygen-containing inert gas, under normal pressure or increased pressure at a temperature of 200-500 deg.C, preferably 250-475 deg.C, thus phenol is obtained from benzene of low cost with one process in high yield and in high purity as by-product is small and selectivity is excellent. Besides, by-produced hydrogen chloride is able to be reused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a new method for producing phenol.

More specifically, the present invention relates to a method for producing phenol in one step by reacting benzene, hydrogen chloride, and oxygen.

[Conventional technology]

Conventionally, as a method for producing phenol from benzene in one step, a direct oxidation method in which benzene and oxygen are reacted in the presence of a catalyst is known.

However, in this case, complete oxidation of benzene occurs and the selectivity for phenol is very low (Japanese Patent Application Laid-open No. 87527/1983).

Furthermore, a method for producing phenol by reacting benzene and nitrous oxide in the presence of a catalyst is also known. However, in this case, the raw material nitrous oxide is expensive and the yield of phenol is low (Catalyst, 21.103.276 (
1982)).

Further, as a phenol production method consisting of two steps, there is a method using monochlorobenzene as an intermediate. That is, in the first step, monochlorobenzene is produced by chlorination or oxychlorination of benzene.

In the second step, monochrome penzene is hydrolyzed to produce phenol in a liquid phase or gas phase reaction.

However, this two-step phenol production method produces many by-products, has low selectivity, and requires a long manufacturing process. ! It's rough. Therefore, a method for producing phenol from benzene in one step has been desired, but it has not yet been commercialized.

[Problem to be solved by the invention] The problem of the present invention is to obtain phenol from benzene in a high yield.
The purpose is to provide an industrial method for manufacturing in a process. That is, an object of the present invention is to provide a method for producing phenol from benzene in one step by eliminating the complete oxidation seen in the direct oxidation method of benzene, which is a method for producing phenol from benzene in one step. .

[! Means to solve problem i]

As a result of various studies regarding the above-mentioned problems, the present inventors discovered that the conventional phenol production method consisting of two steps, namely,
Focusing on a method in which benzene is oxychlorinated to produce monochlorobenzene in the second step, and monochlorobenzene is hydrolyzed to produce phenol in the second step, the benzene oxychlorination process and the monochlorobenzene hydrolysis process are combined. As a result of considering carrying out oxychlorination of benzene and hydrolysis of monochlorobenzene in one step,
The inventors have discovered that phenol can be obtained from benzene in a high yield in one step by using a catalyst that has the dual functions of oxychlorination and hydrolysis, leading to the method of the present invention.

That is, the present invention is a method for producing phenol, which is characterized in that benzene, hydrogen chloride, and oxygen are subjected to a gas phase catalytic reaction in one step in the presence of a catalyst.

In the present invention, oxychlorination and hydrolysis are carried out in one step. The reaction is thought to proceed as shown in the following equation.

2C&)+6 +21(CI+O!→2C,H,CI
+28. O(])2C6H5C+ +2HzO→2C&
H5OH+2)1cI (2)2CJi + ox
→2C6HsOH (3) Formula (1) shows the reaction of oxychlorinating benzene to produce monochlorobenzene. Formula (2) shows the reaction of hydrolyzing the produced monochlorobenzene to produce phenol. Equation (3) is (
This is a combination of Equation 1) and Equation (2). That is,
By oxychlorinating benzene to produce monochlorobenzene in one step and further hydrolyzing the produced monochlorobenzene, phenol can be produced from benzene in one step as shown in equation (3). At this time, benzene and oxygen are consumed as raw materials, while hydrogen chloride and water are necessary for the reaction but are not consumed.

That is, phenol can be produced from benzene via monochlorobenzene as an intermediate in one step. Furthermore, since the reaction according to the present invention is not a direct oxidation of benzene, complete oxidation of benzene can be controlled as much as possible.

The catalyst used in the method of the present invention consists of a catalyst having an oxychlorination function and a catalyst having an 8G hydrolysis ability.

That is, the catalyst used in the present invention consists of a part that performs an oxychlorination action and a part that performs a hydrolysis action. More specifically, the catalyst used in the present invention has active sites that perform oxychlorination and active sites that perform hydrolysis.

Therefore, by using the catalyst according to the invention, the two reactions of oxychlorination and hydrolysis can be carried out in one step.

The catalyst used in the present invention can be used in the following three ways.

(1) One type of catalyst contains active sites that perform oxychlorination and active sites that perform hydrolysis.

That is, the 1MH catalyst has an oxychlorination function and a hydrolysis function.

(2) Two types of catalysts are used in combination: a catalyst with an oxychlorination function and a catalyst with a hydrolysis function.

(3) Consists of two layers: an oxychlorination catalyst layer and a hydrolysis catalyst layer. A catalyst having an oxychlorination function is used in the front layer, and a catalyst having a hydrolysis function is used in the rear layer.

The catalyst having an oxychlorination function used in the present invention is
Usually, metal halides such as copper chloride, iron chloride, chromium chloride, metal oxides such as copper oxide, iron oxide, chromium oxide, copper,
It is a catalyst containing at least one metal such as iron and chromium. These may be used alone or in combination and may include silica, alumina, silica-alumina, zeolite,
It may be used by being supported on a carrier such as diatomaceous earth, activated clay, titanium oxide, or magnesium oxide. Furthermore, published by Kagyo Kogyo Co., Ltd., published by Tarama Laboratory, Kyoto University, “Catalyst Classification Table by Reaction 2”
"Metal chlorides in the oxychlorination catalysts listed in Table 4.3.5 on page 188 - Al2O2, metal halides, CuCIt KCI AhOz, CuCIz-
KCI is also included in the catalysts that can be used in the present invention.

The catalyst having a hydrolysis function used in the present invention is a catalyst that hydrolyzes monochlorobenzene to produce phenol. For example, Kagaku Kogyosha, Kyoto University Tarama Laboratory, “Catalyst Classification Table by Reaction 1,” pp. 166-167 and “
The hydrolysis catalyst for chlorobenzene described in No. 198 IW 2, "Catalyst Partition Table 2 by Reaction", the hydrolysis catalyst described in JP-A No. 63-48238, published by Sangyo Tosho Co., Ltd., written by Kozo Tabe and Tsune Takeshita, "Acid These are metal oxides, metal salts, etc. listed in Table 4-1 Types of Solid Acid Bases on page 160 of ``Base Catalysts''. Among these, phosphoric acid, phosphate, 5iOz gel, CuCIz
, Cu, Nl(,01(, etc.) have excellent catalytic action.

Among phosphates, especially those of rare earth metals, e.g.
Phosphates of yttrium, lanthanum, and cerium are preferred.

The catalyst used in the present invention includes, for example, copper phosphate, chromium phosphate, iron phosphate, and the like as compounds having both an oxychlorination function and a hydrolysis function.

The hydrogen chloride used in the method of the present invention is usually preferably an aqueous hydrochloric acid solution, and its concentration is not particularly limited, but from 0.1 to
A 35-1% aqueous hydrochloric acid solution is preferred. Further, as shown in formula (1), a theoretical amount of water is produced by the oxychlorination reaction of benzene, but a better effect can be obtained by further adding water to the process according to the present invention. Furthermore, water may be added directly to the reaction atmosphere separately from hydrogen chloride.

The amount of benzene and hydrogen chloride to be used is as shown in equation (1), in order for all benzene to change into the corresponding phenol, an equimolar amount or more of hydrogen chloride is required relative to benzene, but dichlorobenzene In order to suppress the by-product of hydrogen chloride, it is desirable to use hydrogen chloride in an amount equal to or less than the mole of benzene.

In the method of the present invention, the reaction is usually carried out in an oxygen or oxygen-containing inert gas atmosphere under normal pressure or increased pressure. Examples of the inert gas include nitrogen, helium, argon, carbon dioxide, and the like. Alternatively, air can be used instead of oxygen.

In the method of the present invention, the reaction temperature is 200-500°C
1 Preferably, the temperature is in the range of 250 to 475°C. 200
``When f4 is full, monochlorobenzene is produced in large quantities, soo
If 'c is exceeded, the yield of phenol decreases and a large amount of by-products are produced.

The method of the invention can be carried out in the gas phase.

That is, it can be carried out in a fixed bed, fluidized bed or moving bed reactor. The process of the invention is also carried out by heating benzene, oxygen and hydrogen chloride vapors in the presence of the catalyst in a reactor or reaction tube. At this time, by adding water or aquatic plants to the raw material vapor, phenol can be obtained in a higher yield and more safely.

In the method of the present invention, phenol can be easily separated and purified from the reaction product by an appropriate method, for example, a conventional method such as distillation.

In the process of the present invention, by-product hydrogen chloride can be returned to the reactor or reaction tube and reused for the oxychlorination of benzene. Furthermore, if monochlorobenzene, which is a by-product, is hydrolyzed, it becomes phenol.

〔Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Granular copper chromium catalyst (JGC N 201, CuO
37%, CrzOs46%, l'1nJ4%), 1.0 g of phosphoric acid HsPOa and 3.0 g of water. After impregnating with Og and drying at 120°C for 3 hours, the obtained copper chromium-phosphoric acid catalyst was filled into a Pyrex glass flow-through reaction tube having an inner diameter of 15 mm. The reaction tube was placed in air for 4
It was fired at 00°C for 2 hours and then at 500'C for 2 hours.

The front part of this reaction tube was connected to a raw material insertion pipe and a gas introduction pipe to constitute a raw material vaporization part, and the rear part was connected to a receiver via an air cooling part. The internal temperature of this reaction tube was maintained at 350°C, and benzene and 11.
A 7 wt % aqueous hydrochloric acid solution was separately introduced into the reaction section through the raw material insertion tube, and at the same time, air was passed through at 30 ml/min under normal pressure.

When the reaction product condensed after exiting the reaction tube was analyzed by gas chromatography, phenol was obtained with a benzene conversion rate of 13%, a phenol selectivity of 32%, and a phenol yield of 4.2%. In addition, monochlorobenzene was obtained with a selectivity of 43%. A small amount of other unknown by-products were also obtained.

Comparative Example 1 In the method carried out in Example 1, only 5 d of granular copper chromium catalyst (Nichiren Chemical N-201) was filled as a catalyst into a reaction tube with an inner diameter of 15 mm, and then the reaction tube was heated at 400°C for 2 hours in nitrogen. Fired. After the reaction was carried out in the same manner as in Example 1, analysis revealed that monochlorobenzene was the main product, and no phenol was observed to be produced.

Comparative Example 2 100 g (0.23 mmol) of La(NO3)s
- Prepare solution (1) by dissolving 6HJ in 400 d of water, and at the same time add 51 g (0.52 mol) of H3P0. 4
Solution (2) was prepared by dissolving 00d in water.Next, solution (2) was added to solution (1) with stirring, and then an aqueous NH3 solution was added to adjust the pH to 6. Stir for hours. Thereafter, the precipitate was filtered from the mother liquor and washed with 5R of water. This precipitate was dried at 120°C for 12 hours, and then calcined in air at 400°C for 3 hours.
LaPO, a catalyst was obtained.

In the method carried out in Example 1, LaPO was used as a catalyst.
After filling a reaction tube with an inner diameter of 15 mm with 4 catalysts 5Id, 4
Calcined at 00°C for 2 hours under nitrogen.

Thereafter, a reaction was carried out in the same manner as in Example 1, and when analyzed, a trace amount of monochlorobenzene was produced, but almost no phenol was produced.

Example 2 CuCIt was added to 5 g of LaPO and catalyst prepared in Comparative Example 2.
・After impregnating 2 HzOO, 34g and 4.0g of water,
It was dried at 120°C for 1 hour and then stored overnight. This LaP
The On-CuCI□ catalyst was filled into a reaction tube with an inner diameter of 15aII11, and calcined in air at soo'c for 3 hours.

The reaction was carried out in the same manner as in Example 1, and the results of analysis are shown below.

Table 1 Example 3 In Example 2, using YPO as a catalyst instead of LaPOa catalyst, YPO4CLICI! A catalyst was prepared and the reaction temperature was set to 400°C, but otherwise the procedure was carried out in the same manner as in Example 2. As a result, the benzene conversion rate was 15% and the phenol selectivity was 48%.
%, and a monochlorobenzene selectivity of 36% was obtained.

Example 4 In Example 2, CePO-
Prepare the CePOa-CuCl, catalyst using a catalyst,
The reaction temperature was set to 400'C, and the same procedure as in Example 2 was carried out except that, as a result, a benzene conversion rate of 12%, a phenol selectivity of 35%, and a monochlorobenzene selectivity of 51% were obtained.

Example 5 In Example 1, a chromia-alumina catalyst (8 Ren Kagaku N-401, Crt0312
%, MgO 3%, AhOs 75%) to prepare a chromia-alumina-phosphoric acid catalyst. Chlorobenzene selectivity 45%
I got it.

Example 6 In the method carried out in Example 1, instead of the copper chromium phosphate catalyst, the reaction tube was filled with granulated CLIz(PO4)z'3HzO, and the reaction temperature was 450°C, and the other conditions were As a result of carrying out the same procedure as in Example 1, the benzene conversion rate was 15%, the phenol selectivity was 38%, and the monochlorobenzene selectivity was 32%.
I got it.

Example 7 In the method carried out in Example 1, 5d of granular CrPOa 6H20 was filled in the reaction tube instead of the copper chromium phosphate catalyst, and the reaction temperature was set to 450'C, except for the same procedure as in Example 1. As a result of carrying out the same procedure, a benzene conversion rate of II%, a phenol selectivity of 26%, and a monochlorobenzene selectivity of 38% were obtained.

Example 8 In the method carried out in Example 1, instead of the chromium-phosphate catalyst, CrPO= .6) 1xO12,76
g (0.05 mol) and Cu1(PO4)z ・31(
After mixing 21.73 g (0.05 mol) of zo, adding water and kneading, calcining at 120°C for 2 hours and 400'C for 5 hours, the 5d was filled into a reaction tube and reacted. The temperature was set to 450°C, and the other conditions were the same as in Example 1. As a result, the benzene conversion rate was 14%, and the phenol selectivity was 4.
1% and a monochlorobenzene selectivity of 37%.

Example 9 In the method carried out in Example 1, 5 g of copper chromium catalyst and LaPO4 of Comparative Example 2 were used instead of the chromium phosphate catalyst.
5 g of catalyst was mixed and charged into the reaction tube, and the rest was carried out in the same manner as in Example 1. As a result, the benzene conversion rate was 16%, the phenol selectivity was 31%, and the monochlorobenzene selection rate was 40%.
I got %.

Example 10 In the method carried out in Example 1, instead of the inner chromium phosphate catalyst, 5 g of the inner chromium catalyst was used as the front layer and 5 g of the LaPOm catalyst of Comparative Example 2 was used as the back layer, and the reaction tube was filled in two layers. Other than that, the same procedure as in Example 1 was carried out, and as a result, a benzene conversion rate of 18%, a phenol selectivity of 28%, and a monochlorobenzene selectivity of 42% were obtained.

〔Effect of the invention〕

In the method of the present invention, phenol can be produced in one step by subjecting benzene, hydrogen chloride, and oxygen to a gas phase contact reaction in the presence of a catalyst.

According to the method of the present invention, there are the following advantages.

(1) The raw material is cheap like benzene.

(2) Phenol is produced from benzene in step (■).

(3) Good yield of phenol.

(4) There are few by-products, the selectivity is good, and therefore highly pure phenol can be obtained.

(5) Hydrogen chloride produced as a by-product can be used again.

(6) As shown in equation (3), the overall reaction is an oxidation reaction between benzene and oxygen, but complete oxidation can be suppressed.

(7) Monochlorobenzene produced as a by-product can be hydrolyzed into phenol.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) In the presence of a catalyst, benzene, hydrogen chloride, and oxygen are
A method for producing phenol characterized by a gas phase catalytic reaction in the process. 2) The method according to claim 1, wherein the gas phase catalytic reaction is carried out in the presence of water. 3) The method according to claim 1, wherein the catalyst has an oxychlorination function and a hydrolysis function. 4) The method according to claim 2, wherein the catalyst has an oxychlorination function and a hydrolysis function. 5) The method according to any one of claims 1 to 4, wherein the hydrogen chloride is an aqueous hydrochloric acid solution.