JP2009249332A - Method for producing phenol by direct oxidation of benzene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing phenol from benzene. <P>SOLUTION: The method for producing phenol is characterized by oxidizing benzene by oxygen, in the presence of ammonia and a composite catalyst formed from rhenium, a group 10 metal and a metal oxide. The metal oxide is preferably aluminosilicate, more preferably zeolite, especially preferably ZSM-5; and the group 10 metal is preferably platinum. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a process for producing phenol by direct oxidation of benzene.

  As an industrial production method of phenol using benzene as a raw material, for example, a method of obtaining phenol from benzene and propylene via cumene hydroxy peroxide is mainly performed (cumene method). However, in this method, acetone co-produces, but there is a problem of balance between supply and demand of both products, and it is economically inefficient because it is a three-stage process. On the other hand, a method of oxidizing toluene to phenol (toluene method) has also been performed, but it is no longer an advantageous method due to the rising price of toluene. Under such circumstances, a method for directly obtaining phenol from benzene free of by-products has been demanded.

As a method for directly obtaining phenol from benzene, in addition to a method of using molecular oxygen as an oxidizing agent, a method of using a special oxidizing agent and a reducing agent stoichiometrically is known.
As a method of using molecular oxygen as an oxidizing agent, a method using the following catalyst has been proposed.

(A) Pd (OAc) ₂ / heteropoly compound catalyst (100 ° C.); benzene conversion 10%, phenol selectivity 20% (for example, see Non-Patent Document 1).
(B) VCl ₃ catalyst (50 ° C.); benzene conversion 0.026%, phenol selectivity 86% (
For example, see Non-Patent Document 2.)

  However, direct oxidation with molecular oxygen has high phenol reactivity with benzene polymers such as biphenyl and benzene, and therefore sequential hydroxides of phenol (catechol, pyrogallol, etc.) are by-produced. Therefore, a high phenol selectivity cannot be obtained unless the conditions are extremely low, and it has not been put to practical use.

  Non-Patent Document 3 describes that rhenium immobilized in zeolite pores generates phenol with high selectivity from benzene and oxygen in the presence of ammonia. This catalyst can be obtained by subjecting H-ZSM-5 to methyltrioxorhenium, which is a sublimable complex, after chemical vapor deposition and then treating with ammonia. The reaction is carried out by a gas phase contact method. After a predetermined amount of the catalyst is filled in the reaction tube, an activation treatment is performed at a predetermined temperature under an inert gas flow, and then benzene and oxygen are passed through the catalyst layer at a predetermined ratio. Is done. However, the conversion rate of benzene was low and it could not be said that the results were sufficient.

  As a method using a special oxidizing agent, a method using expensive nitrous oxide or hydrogen peroxide has been reported (for example, see Non-Patent Documents 4, 5 or 6). However, these special oxidizers require equimolar amounts relative to the phenol to be produced, and are not economically feasible as a phenol production method that is expected to be mass-produced as a general-purpose chemical product. Not in.

As a method of using a reducing agent in combination, a method of using H ₂ in combination (for example, see Non-Patent Document 7) and a method of using CO in combination (for example, see Patent Documents 1, 2, or 3) are known. However, due to the low selectivity of phenol due to sequential reaction, H ₂ is consumed as a large amount of water, safety issues (CO toxicity, danger of explosion due to O ₂ and H ₂ ), etc. It has not led to.
JP-A-61-387 JP-A-61-135217 JP-A-62-67038 J. Mol. Catal. A: Chemical, 185, 285-290 (2002) J. Mol. Catal. A: Chemical, 202, 107-115 (2003) Angew. Chem. Int. Ed., 45, 448-450 (2006) Applied Catal. A: General, 244, 11-17 (2003) Applied Catal. A: General, 243, 41-51 (2003) Angew. Chem. Int. Ed., 42, 4937-4940 (2003) J. Mol. Catal. A: Chemical, 178, 199-204 (2002)

  An object of the present invention is to provide a method for efficiently producing phenol from benzene.

  As a result of diligent research to solve the above problems, the present inventors have found that phenol can be efficiently produced by oxidizing benzene with oxygen in the presence of a specific composite catalyst and ammonia, and the present invention has been achieved. did.

  That is, the method for producing phenol of the present invention is characterized in that benzene is oxidized with oxygen in the presence of a composite catalyst formed from rhenium, a metal of Group 10 of the periodic table, and a metal oxide, and ammonia. .

The metal oxide is preferably an aluminosilicate, more preferably zeolite, and particularly preferably ZSM-5.
The metal of Group 10 of the periodic table is preferably platinum.

  According to the present invention, phenol can be produced from benzene with high selectivity and high conversion.

  The phenol production method of the present invention is characterized in that benzene is oxidized with oxygen in the presence of a composite catalyst formed of rhenium, a metal of Group 10 of the periodic table, and a metal oxide, and ammonia.

  As the metal oxide, an aluminosilicate known as a catalyst carrier is suitable, and zeolite is more preferred. Specific examples of the zeolite include Y-type, L-type, mordenite, ferrierite, beta-type, ZSM-5 and the like. Of these, ZSM-5 is preferred.

The silica / alumina ratio (SiO ₂ / Al ₂ O ₃ ) (molar ratio) of the zeolite is not particularly limited, but is preferably 200 to 0.001, and particularly preferably 100 to 0.01.

The cation species of the zeolite is not particularly limited, but ammonium type (NH ₄ ⁺ ) / proton type (H ⁺ ) zeolite is preferable.
The composite catalyst used in the present invention must contain both rhenium and Group 10 metal in addition to the metal oxide. By containing both rhenium and Group 10 metal of the periodic table, the composite catalyst efficiently oxidizes benzene with oxygen with high selectivity and high conversion,
Phenol can be obtained.

The use ratio of rhenium to Group 10 metal of the Periodic Table (Renium / Group 10 metal of the Periodic Table) is preferably 10 to 0.001 by weight.
Specific examples of the rhenium precursor compound used in the preparation of the composite catalyst include ammonium perrhenate, methyltrioxorhenium, rhenium carbonyl, rhenium chloride (III
, IV, V), rhenium pentacarbonyl bromide, rhenium pentacarbonyl chloride,
Examples include rhenium silicide and rhenium (IV) sulfide.

  As the metal of Group 10 of the periodic table, platinum, palladium, and nickel are preferable, and platinum is particularly preferable. The metals in Group 10 of the periodic table may be used alone or in a combination of two or more.

When the group 10 metal of the periodic table is platinum, specific examples of the platinum precursor compound used in preparing the composite catalyst include tetraamminepalladium (II) nitrate, platinum chloride (II).
), Chloroplatinic acid (IV), dinitrodiammine platinum (II), tetraamminedichloroplatinum (II), dichlorotetraammineplatinum (II), platinum oxide (IV), potassium tetrachloroplatinate (II), hexahydroxoplatinic acid ( IV) and hexachloroplatinic acid (IV).

When the Group 10 metal of the periodic table is palladium, specific examples of the palladium precursor compound used in the preparation of the composite catalyst include palladium chloride (II), palladium nitrate (II), dinitrodiammine palladium (II ), Tetraamminepalladium (II) dichloride, palladium (II) acetate, palladium hydride and palladium oxide.

  When the group 10 metal of the periodic table is nickel, specific examples of the nickel precursor compound used in the preparation of the composite catalyst include nickel chloride (II), nickel carbonate, nickel carbonyl, nickel sulfate (II). Nickel nitrate (II), nickel oxide (II), nickel hydroxide (II), nickel acetate (II).

The composite catalyst can be obtained, for example, by adding rhenium and the Group 10 metal of the periodic table to the metal oxide.
The composite catalyst used in the present invention preferably has a weight ratio of the metal oxide to rhenium (rhenium / (rhenium + metal oxide)) of 0.01 / 100 to 50/100, 0.05 / More preferably, it is 100-30 / 100, and it is especially preferable that it is 0.1 / 100-10 / 100.

  Conventionally known methods such as physical mixing, impregnation, precipitation, kneading, and chemical vapor deposition can be applied to the metal oxide to contain rhenium and Group 10 metal of the periodic table. Is possible. The order in which the two kinds of metals are introduced into the metal oxide is not particularly limited, and rhenium and the metals of Group 10 of the periodic table may be introduced into the metal oxide at a time, or each may be introduced stepwise. Is also possible.

  The composite catalyst is preferably used after pretreatment. Pretreatment is performed using oxygen and ammonia. As a specific method of the pretreatment, the composite catalyst is treated in an oxygen atmosphere at a temperature of 300 to 500 ° C. for 0.5 to 2 hours, and further in an ammonia atmosphere at a temperature of 300 to 500 ° C. A method of treating for ˜2 hours, or a method of treating for 0.5 to 2 hours at a temperature of 300 to 500 ° C. in a mixed system atmosphere composed of oxygen and ammonia.

The phenol according to the present invention is produced by an oxidation reaction in which oxygen is directly added to benzene in the presence of the composite catalyst and ammonia. The oxidation reaction is preferably performed by a gas phase contact method. The oxygen is preferably molecular oxygen. The reactor is not particularly limited, and can be implemented in a fixed bed or a fluidized bed.

  The reaction temperature of the oxidation reaction is 50 to 700 ° C, preferably 100 to 600 ° C. The reaction pressure of the oxidation reaction is 0.01 to 100 MPa, preferably 0.05 to 10 MPa.

The use ratio of the composite catalyst in the oxidation reaction is 0.01 to 100 g-cat · h in terms of W / F value.
· Mol ^-1 , preferably 0.01 to 50 g-cat · h · mol ^-1 .
The ratio of oxygen used in the oxidation reaction is 0.01 to 50 mol, preferably 0.1 to 10 mol, per mol of benzene. The ratio of ammonia used in the oxidation reaction is 0.001 to 200 mol, preferably 0.01 to 100 mol, per mol of benzene. In the oxidation reaction, oxygen and ammonia can be diluted with an inert gas such as nitrogen, helium or argon gas.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
[Example 1]
Commercially available Na ⁺ -ZSM-5 ((SiO ₂ / Al ₂ O ₃ ) = 23.8) was stirred in a 1N aqueous ammonium nitrate solution, filtered, washed with ion-exchanged water, and then dried at 120 ° C. to obtain NH ₄ ⁺ -ZSM-5 was obtained.

Impregnation with NH ₄ ReO ₄ (0.216 g) and ion-exchanged water (4 ml) and NH ₄ ⁺ -ZSM-5 (3.0 g) obtained above, followed by drying at 120 ° C. As a result, 5 wt.% Re / NH ₄ ⁺ -ZSM-5 was obtained.

An aqueous solution composed of [NH ₃ ] ₄ Pt (NO ₃ ) ₂ (0.119 g) and ion-exchanged water (4 ml), 5 wt.% Re / NH ₄ ⁺ -ZSM-5 (3.0 g) obtained above. ) And then dried at 120 ° C. to obtain a catalyst (Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5).

The catalyst (Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5) was pretreated under an oxygen flow as a pretreatment.
The treatment was performed at 0 ° C. for 1 hour. Subsequently, the mixture was subjected to a reaction at 350 ° C. for 30 minutes under NH ₃ flow.

Benzene / oxygen / ammonia / helium = 1.0 / 2.0 / with respect to the catalyst (1.0 g)
6.5 / 7.5 subjecting the mixed gas (molar _{ratio) (GHSV = 72ml / g -cat} · h), 0.1MPa, reaction was carried out at 240 ° C.. After sampling, the reaction gas was quantitatively analyzed by gas chromatography.

When the product was analyzed, Example 1 using Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5 as a catalyst had a benzene conversion of 2.2% and a selectivity at the beginning of the reaction. Phenol was produced in 79%.

[Comparative Example 1]
The reaction was carried out under the same reaction conditions as in Example 1 except that Re (5 wt.%) / NH ₄ ⁺ -ZSM-5 without addition of platinum was used as a catalyst, and the product was analyzed. Phenol was produced at a rate of 0.9% and a selectivity of 84%.

[Example 2]
Commercially available Na ⁺ -ZSM-5 ((SiO ₂ / Al ₂ O ₃ ) = 23.8) was stirred in a 1N aqueous ammonium nitrate solution, filtered, washed with ion-exchanged water, and then dried at 120 ° C. to obtain NH ₄ ⁺ -ZSM-5 was obtained.

Impregnation with NH ₄ ReO ₄ (0.216 g) and ion exchange water (4 ml) and NH ₄ ⁺ -ZSM-5 (3.0 g) obtained above, followed by drying at 120 ° C. 5wt.% Re / NH ₄ ⁺ -ZSM-
5 was obtained.

An aqueous solution composed of [NH ₃ ] ₄ Pt (NO ₃ ) ₂ (0.119 g) and ion-exchanged water (4 ml), 5 wt.% Re / NH ₄ ⁺ -ZSM-5 (3.0 g) obtained above. ) And then dried at 120 ° C. to obtain a catalyst (Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5).

The catalyst (Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5) was pre-treated under oxygen flow, 500
The treatment was carried out at 1 ° C. for 1 hour. Subsequently, the mixture was subjected to a reaction at 350 ° C. for 30 minutes under NH ₃ flow.

Benzene / oxygen / ammonia / helium = 1.0 / 2.0 / with respect to the catalyst (1.0 g)
Provide a mixed gas at 12.8 / 7.5 (molar ratio) (GHSV = 36 ml / g- _cat · h), 0.1 MPa,
The reaction was carried out at 240 ° C. After sampling, the reaction gas was quantitatively analyzed by gas chromatography.

When the product was analyzed, Example 2 using Re (5 wt.%)-Pt (2 wt.%) / NH ₄ ⁺ -ZSM-5 as a catalyst had a benzene conversion of 3.7% at the beginning of the reaction. Phenol was produced at a rate of 84% (1 hour after the start of the reaction).

[Comparative Example 2]
The reaction was carried out under the same reaction conditions as in Example 2 except that Re (5 wt.%) / NH ₄ ⁺ -ZSM-5 without addition of platinum was used as a catalyst, and the product was analyzed. Phenol was produced at a conversion of 1.1% and a selectivity of 85% (1 hour after the start of the reaction).

Claims (5)

  A composite catalyst formed from rhenium, a metal of Group 10 of the periodic table and a metal oxide, and a method for producing phenol characterized by oxidizing benzene with oxygen in the presence of ammonia.   The method for producing phenol according to claim 1, wherein the metal oxide is an aluminosilicate.   The method for producing phenol according to claim 2, wherein the aluminosilicate is zeolite.   The method for producing phenol according to claim 3, wherein the zeolite is ZSM-5.   The method for producing phenol according to any one of claims 1 to 4, wherein the metal of Group 10 of the periodic table is platinum.