JPH03206060A - Production of phenols - Google Patents

Abstract

PURPOSE:To stably obtain the aimed compound in a high yield by using nickel- containing crystalline metallosilicate as a catalyst in transformation of a halogenated aromatic compound to phenols with hydrolyzing in a vapor phase. CONSTITUTION:A halogenated aromatic compound is hydrolyzed in a vapor phase using nickel-containing crystalline metallosilicate molded preferably by low-acidic binder, especially silica as a catalyst to stably obtain phenols in a high yield using the above-mentioned catalyst generating extremely slighter loss of an active component during reaction as compared with a connectional copper-based catalyst. Besides, said catalyst has a structure resemble to ZSM-5, ZSM-11 or AZ-1 and contains Al and B as metal components preferably having a molar ratio of Si to the metal components of >=10, especially 15-500. Further, a containing amount of Ni is 0.01-20wt.%, preferably 0.01-10wt.% and especially 0.2-5wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing phenols by hydrolyzing a halogenated aromatic compound in a gas phase. More specifically, the present invention relates to a method for producing phenols by hydrolyzing a halogenated aromatic compound, which is characterized by using a nickel-containing metallosilicate as a catalyst.

(Prior Art) As a method for producing phenols by hydrolyzing halogenated aromatic compounds in the gas phase, a method using copper-supported calcium abatite phosphate as a catalyst (US Pat. No. 2,988,573) etc.), a method using zirconium phosphate supporting cavities as a catalyst (Japanese Patent Publication No. 51-61
08 Publication), a method using a rare earth metal phosphate supporting copper as a catalyst (Japanese Unexamined Patent Publication No. 47-27936), a method using a crystalline aluminosilicate containing a metal component as a catalyst (Japanese Unexamined Patent Publication No. 62-192330) Publication, JP-A-62
-281834), a method using crystalline porosilicate as a catalyst (Japanese Unexamined Patent Publication No. 62-240635), a method using crystalline iron silicate as a catalyst (Japanese Unexamined Patent Publication No. 62-240635)
40636), a method using crystalline chromosilicate as a catalyst (Japanese Unexamined Patent Publication No. 62-2406)
3 No. 4) is known.

(Problem to be solved by the invention) However, catalysts such as lucium apatite phosphate, zirconium phosphate, and rare earth phosphates have low activity;
It is necessary to carry out the reaction at a high temperature of 00"C or higher and at a low space velocity. Also, although crystalline metallosicate-based catalysts have relatively high activity, the most effective activity of any of these catalysts is Since the copper component is scattered and lost as copper halide during the reaction, there are problems such as an irreversible decline in the activity of the catalyst over time, which is not at an industrially satisfactory level.

(Means for Solving the Problems) The present inventors have conducted intensive studies on a method for stably producing phenols in a high yield by hydrolysis from halogenated aromatic compounds, and found that nickel The inventors have discovered that the above-mentioned problems can be solved by using the crystalline metallosilicate containing crystalline metallosilicate as a catalyst. Compared to copper-based catalysts, nickel-containing crystalline metallosilicate catalysts have extremely little loss of active components during the reaction, can produce phenols stably, and have the same or higher catalytic activity. This is what I discovered.

The halogenated aromatic compounds used in the present invention include:
One or more of a chlorine atom or a bromine atom is directly substituted on an aromatic nucleus, such as chlorobenzene, dichlorobenzene, bromobenzene, dibromobenzene,
Examples include halogen-substituted benzenes such as chlorotoluene, promotoluene, chloroxylene, and promoxylene, and halogen-substituted naphthalenes such as chloronaphthalene and promonaphthalene.

The catalyst used in the present invention is a nickel-containing crystalline metallosilicate, such as ZSM-5, ZSM-11, AZ-
1 (JP-A-59-128210) Those having a similar structure are preferably used. The metal of the crystalline metallosilicate may be any metal used in known metallosilicates, such as aluminum, boron, chromium, iron, panadium, gallium, and titanium. Preferably it contains aluminum and boron. The atomic ratio of silicon and metal content in these metallosilicates is 10.
Above, preferably 15 or more and 500 or less.

The content of nickel is 0.01 to 203131%,
Preferably 0.1 to 10% by weight, more preferably 0.1% by weight.
It is 2 to 5% by weight. Nickel can be added using known methods such as impregnation, ion exchange, powder blending or kneading a nickel compound (preferably nickel chloride), and adding it as a nickel salt during hydrothermal synthesis of crystalline metallosilicate. can be used.

These crystalline metallosilicates are usually used in the form of a binder by adding a binder made of an inorganic oxide, but f[ of the binder is preferably one with low acidity because of its influence on the selectivity of phenol. When a highly acidic binder is used, by-products such as benzene, which is a dehydrohalogenation by-product, increase. Examples of the low acidity binder include silicon, zirconia, titania, silica/magnesia, silica/beryria, silica/titania, and germanium. These may be used alone or in combination with alkali or alkaline earth metal oxides.

Particularly preferred is silica.

Furthermore, the crystalline metallosilicate used in the present invention is heat-treated at a temperature of 200 to 700'C in the presence of steam, or at a temperature of 600 to 850'C in the absence of steam, and the crystalline metallosilicate used in the present invention is phenol-selective. It is preferably used from the viewpoint of properties and stability of the catalyst.

The reaction conditions in the present invention vary depending on the raw material halogenated aromatic compound, but the reaction temperature is usually 250 to 600°C, preferably 300 to 550°C, and more preferably 350 to 500°C. The molar ratio of water to the halogenated aromatic compound is 0.5 to 100.
, preferably 1 to 50, more preferably 2 to 20. The feed rate of the raw material halogenated aromatic compound is 0.05 to 20 in terms of weight hourly space velocity (WHSV).
Hr-', preferably 0.1 to 10 Hr-' is used.

(Effects of the Invention) According to the method of the present invention, phenols can be stably produced in higher yield than halogenated aromatic compounds.

(Example) The present invention will be specifically explained by giving examples below.
It is not limited to this.

Example 1 Z SM 5 (Sing/A
f t's=45) was hydrothermally combined, then made into a sodium form using a sodium chloride aqueous solution by a conventional method, and then nickel-exchanged using a nickel nitrate aqueous solution to obtain a product containing 0.6% by weight of nickel. I let it happen. This nickel-containing ZSM-5 was kneaded using silica sol as a binder, extruded, dried, and then calcined at 550"C for 4 hours (the amount of binder was 30% by weight as silica) as a catalyst. Using.

The reaction was carried out by filling a 10 mm diameter quartz reaction tube with 10 g of catalyst, heating it to a predetermined temperature in a heating furnace, and supplying predetermined amounts of chlorobenzene and water with a metering pump to carry out a hydrolysis reaction. The reaction conditions were 450°C, water/chlorobenzene molar ratio 6, and chlorobenzene supply IWHsV of 0. 2
I went with Hr-'. Analysis of the sampled liquid 2 to 3 hours after the start of the flow revealed that the conversion rate of chlorobenzene was 46%, the phenol yield was 40 molX, the by-product was mostly benzene, and the total selectivity of benzene and phenol was 98.
It showed 6%.

When the reaction continued for 50 hours, the catalyst was taken out and the amount of nickel was measured, and the decrease in nickel was 1%.
It was below.

Example 2 Similar to Example 1, except that a shaped catalyst using alumina sol as binder was used in the reaction. The reaction conditions were the same as in Example 1.

The conversion rate of chlorobenzene is 28% and the yield of phenol is 23 mol! Met. The total selectivity of benzene and phenol was 97.5%.

Example 3 Same as Example 1, except that ZSM-5 used as a catalyst in Example 1 was heat treated at 850°C in an air atmosphere for 4 hours, and then Na exchanged and Ni exchanged (nickel content 0.4% by weight). ) was used. Reaction temperature 460"C, W
HSV=0.2 5Hr-', water/chlorobenzene ratio 5
．． The hydrolysis reaction was carried out under the conditions of 8. 2~ after starting the reaction
The reaction result at the 3rd hour was a conversion rate of chlorobenzene of 35%.
, the yield of phenol was 31%.

Example 4 Sing/A j! by a known method. ZSM-5 with a zOs ratio of 70 was hydrothermally combined and treated in the same manner as in Example 1 to prepare a Ni-containing ZSM-5 catalyst using a silica binder (nickel content 0.4% by weight/zeolite).

The hydrolysis reaction of chlorobenzene was carried out in the same manner as in Example 1 at 450°C and WHSV=0. 2Hr-', water/
The reaction conditions were such that the molar ratio of chlorobenzene was 10. 2-3
The conversion rate of chlorobenzene at the time point was 20%, and the selectivity of phenol was 95 moIX. The conversion rate of chlorobenzene at 12 hours after 1O was 17%, and the selectivity of phenol was 96 mo1z. After 15 hours of reaction, the catalyst was taken out and the nickel content was measured using a fluorescence X analyzer, and no decrease in nickel was observed.

Comparative Example 1 A chlorobenzene hydrolysis experiment was conducted in the same manner as in Example 1, except that copper was used instead of nickel, and the same formulation and conditions were used. The conversion rate of chlorobenzene during the second to third hours of the reaction was 40%, the yield of phenol was 37 molX, and the selectivity for benzene and phenol combined was 95a+oH. The reaction continued for 10 hours, and the catalyst was removed.
When the amount of copper, which is an active ingredient, was measured, a 10% decrease was observed.

When the amount of copper in the catalyst was measured after reacting with the same catalyst for 50 hours under the same conditions, the amount of copper showed a decrease of 50%.

Example 5 A solution prepared by dissolving 256 g of silica sol (silica content 30% by weight), 7.4 g of nickel nitrate hexahydrate, and 60 g of tetrabubyl ammonium bromide in 220 g of pure water was converted under strong stirring, and then, 20 g of a 20% by weight aqueous solution of caustic soda was added to form a gel. Pour this gel into a 1 liter Teflon-lined autoclave,
Hydrothermal synthesis was carried out at 0°C and 600 rpm for 60 hours. The resulting slurry was filtered, washed with water, dried at 110''C for 6 hours, and then calcined at 500''C in air to obtain nickel silicate. The nickel content was 1.6%, and X-ray diffraction analysis showed a diffraction pattern similar to ZSM-5. This product was compression molded, then crushed and sieved to 8 to 20 mesh, and used as a catalyst, reaction temperature 4 50'C, WH
SV=0.29Hr-', water/chlorobenzene molar ratio 6
The hydrolysis reaction of chlorobenzene was carried out under the conditions that the amount of diluting nitrogen was set to a nitrogen/chlorobenzene molar ratio of 1.1.

Claims (2)

[Claims] (1) A method for producing phenols, which comprises using a nickel-containing crystalline metallosilicate as a catalyst when converting a halogenated aromatic compound into phenols by hydrolyzing it in the gas phase. (2) The method according to claim 1, wherein the nickel-containing crystalline metallosilicate is molded using a binder with low acidity.