JPH05286880A - Production of o-position methylated phenol compound - Google Patents

Abstract

PURPOSE:To improve conversion ratio of phenol, to efficiently produce both o-cresol and 2,6-xylenol in a desired production ratio and to obtain the subject compound useful as a raw material for resin by subjecting phenol, etc., and methanol to a vapor-phase contact reaction under a specific condition. CONSTITUTION:Phenol and/or o-cresol and methanol are subjected to a vapor- phase contact reaction in the presence of an oxide of a metal such as iron, vanadium or manganese in a fluidized bed by using a reactor horizontally equipped with an insert at least at one place to give the objective compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an ortho-positioned methylated phenol compound in which a phenol or / and orthocresol and methanol are subjected to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed. The present invention relates to a method in which orthocresol and 2,6-xylenol are efficiently co-produced at a desired production ratio by improving the phenol conversion rate by providing the insert horizontally.

The ortho-methylated phenol compounds produced by the method of the present invention are all useful as industrial raw materials. For example, 2,6-xylenol is a raw material for polyphenylene ether and a raw material for agricultural chemicals.
-A raw material for xylidine, while orthocresol is useful as a raw material for medicines, agricultural chemicals and the like.

[0003]

2. Description of the Related Art A method for producing an ortho-positioned methylated phenol compound by bringing phenol or / and orthocresol and methanol into contact with each other in a gas phase is known and is industrially practiced. Regarding the fluidized bed reaction, for example, Japanese Patent Publication No. 2-33693 discloses a method of reacting in a fluidized bed using a metal oxide supported on silica as a catalyst.

In general, when a reaction with exotherm is carried out using a fixed bed reactor, local heating is likely to occur, and particularly in an industrial scale fixed bed reactor, it is extremely difficult to prevent local heating. The product yield, the selectivity, and the catalyst life may be shortened.

Further, in the ortho-methylation reaction of phenols, a decomposition reaction of methanol occurs. The decomposition of methanol has a characteristic of acceleratingly increasing when the reaction temperature is high. Therefore, in the ortho-methylation reaction, the uniformity of the reaction temperature is particularly required.

On the other hand, when a fluidized bed reactor is used, it is easy to keep the temperature inside the reactor uniform.
However, the fluidized bed reactor also has problems to be solved. For example, the gas in the fluidized bed rises mainly in the suspension phase of the catalyst particles while forming bubbles, and coalescence and redispersion are repeated in the middle of the rise. Of substances between gas phase and bubble phase, deterioration of gas mixing in each phase, contact efficiency between gas and solid decreases, and in extreme cases, gas flow-through phenomenon occurs and conversion rate greatly decreases. ..

Therefore, in the prior art, the gas-solid contact efficiency is poor, the phenol conversion is low at the desired production ratio, let alone orthocresol and 2,6-
Xylenol could not be co-produced efficiently.

[0008]

The object of the present invention is to produce an ortho-methylated phenol compound by subjecting phenol or / and orthocresol and methanol to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed. , Orthocresol and 2,6-xylenol can be co-produced efficiently at a desired production ratio.

[0009]

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention which is industrially extremely advantageous. That is, the present invention is a method for producing an ortho-methylated phenol compound in which a phenol or / and orthocresol and methanol are subjected to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed. The method for producing a methylated phenol compound at the ortho position is characterized by using the reaction device provided in.

When phenol or / and orthocresol and methanol are subjected to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed to produce an ortho-methylated phenol compound, the gas in the fluidized bed is a catalyst suspension phase. It rises while forming bubbles mainly inside, and coalescence and redispersion are repeated in the middle of the rise. Therefore, a gas flow-through phenomenon occurs, and the reaction in the fluidized bed generally has a lower conversion rate than the reaction in the fixed bed.

According to the method of the present invention, since the reactor is horizontally provided with the insert, it is possible to divide the bubbles, and to divide and re-disperse the coalesced and grown bubbles. Thereby, the substance exchange between the suspension phase and the bubble phase and the gas mixing in each phase can be promoted, the contact efficiency between gas and solid can be improved, and the conversion rate close to that of a fixed bed can be obtained.

As shown in FIG. 1, when the desired production ratio of orthocresol and 2,6-xylenol takes a certain value A, an attempt is made to increase the phenol conversion rate (for example,
According to the curve n (when the reaction temperature is raised), the production ratio changes to B. That is, a desired production ratio cannot be obtained. However, when the insert according to the method of the present invention is installed, the phenol conversion rate is surprisingly increased while the desired production ratio A is maintained. That is, when an interpolator is installed, the correlation between the production rate and the phenol conversion rate is the curve m.
As a result, the phenol conversion rate increases with respect to an arbitrary production rate as compared with the case where the insert is not installed.

As a result, the amount of unreacted phenol decreases due to the increase in the phenol conversion rate due to the installation of the insert. This is economically advantageous because it can reduce the construction cost of the rectification tower and the like and can reduce the operation cost when the unreacted phenol is reused as a raw material.

The present invention will be described in detail below. When phenol or / and orthocresol and methanol are subjected to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed reactor to produce an ortho-positioned methylated phenol compound,
The reactor is provided with at least one insert horizontally.

The insert in the present invention may be in any form such as a lattice or a perforated plate. However, the lattice is preferable because it can prevent bubbles from coalescing, can be divided uniformly, and can have a high aperture ratio. Further, the position at which the insert is provided is preferably 1/2 or less of the height of the reactor. This is because, as shown in FIG. 2, the rich phase (phase with a high catalyst particle density) 2 is approximately 1/2 or less of the reactor 1, and the interpolated material (lattice) 3, 3 ′, 3 ″ is added here. This is because, if provided, it has the effect of dividing the bubbles, where 4 is a dispersion plate, 5 is a source gas introduction pipe, and 6 is a reaction raw gas outflow pipe.

The number of inserts in the present invention may be one, or a plurality of inserts may be provided. The effect is almost the same. However, when the height of the rich phase is high, it is preferable to provide a plurality of sheets. When a plurality of inserts are used in the present invention, they may be inserted at regular intervals in the height direction, but they may be arranged at different intervals. In the case of one sheet, it is preferable to install it in the middle of the rich phase.

The aperture ratio of the insert used in the present invention is 70%.
It is preferably 95% or more and 95% or less, and more preferably 80% or more and 90% or less. When the opening ratio is lowered, the catalyst circulation is deteriorated and local heating occurs. Moreover, when the aperture ratio is increased, the contact efficiency is not improved. However, as shown in FIG. 3, the opening ratio is the ratio of the area of the portion excluding the internal structure such as the heat removal tube and the rib 7 for mounting the insert 3 to the area of the opening.

The linear gas velocity of the reactor in the present invention is 0.
5 to 100 cm / sec. The particle size of the catalyst applied to the present invention is, for example, as shown in Japanese Patent Publication No. 2-33693, the average particle size is 40 to 100 μ, and 0.2 to 0.7 times the average particle size. , The total weight of particles in each particle size range exceeding 1.5 to 2.0 times and 2.0 times is 5 to 50%, 5 to 30% and 10% or less with respect to the total amount of catalyst. ..

The components of the catalyst applied to the present invention are, for example, Japanese Patent Publication No. 2-33693 and Japanese Patent Publication No. 63-34139.
As shown in No. 6, as the metal component, there are iron, vanadium, manganese, magnesium, chromium, indium alone or in combination, further, by adding an alkali metal, alkaline earth metal, rare earth metal, etc. to these components. May be used.

In the case of producing 2,6-xylenol or / and orthocresol in the present invention, the molar ratio of methanol to phenol or / and orthocresol in the feedstock varies depending on the catalyst species, but is 1: 1.
~ 20. Water vapor or an inert gas can be introduced as necessary, but in the case of water vapor, the molar ratio to phenol and / or orthocresol is 1: 0 to 1
5 is preferable. The reaction temperature varies depending on the catalyst species, but is 25
The range of 0 to 600 ° C. is preferable. The reaction pressure can be normal pressure, reduced pressure or increased pressure.

[0021]

INDUSTRIAL APPLICABILITY In the present invention, the phenol conversion rate can be improved and orthocresol and 2,6-xylenol can be efficiently coproduced at a desired production ratio.

[0022]

The present invention will be described below with reference to examples. The phenol conversion and selectivity in the examples are defined by the following formulas 1 and 2. In addition, orthocresol, 2,6-
The xylenol selectivity is similar.

[0023]

[Equation 1]

[0024]

[Equation 2]

Example 1 Phenol, methanol, iron oxide and vanadium oxide supported on silica were used for a gas phase catalytic reaction in a fluidized bed reactor. The catalyst is pure water 18 obtained by heating 8.8 kg of ammonium metavanadate (NH ₄ VO ₃ ) to 90 ° C.
Dissolve it in 6.0 kg and ferric nitrate (Fe
_{(NO 3) 3 · 9H 2} O) 30.3kg and 30 wt%
42.8 kg of SiO ₂ -containing silica sol (Snowtex N manufactured by Nissan Kagaku) is added. A fine-grained suspension slurry uniformly dispersed in silica sol colloid is obtained. This was dried with a co-current type spray dryer.

The atomization of the raw material slurry can be carried out by any of the industrially used centrifugal system, two-fluid nozzle system and high-pressure nozzle system, but the centrifugal system is particularly preferred. In the centrifugal system, the particle size can be distributed between 10 and 150 μ, which is suitable for use in a fluidized bed reactor, by controlling the rotation speed of the disk and the feed rate of the slurry.

The obtained dry powder was pre-baked at 350 ° C. for 2 hours using a tunnel kiln, and then at 750 ° C. for 3 hours.
Time firing was performed. Using this catalyst 4.5kg, diameter 4
One grid was installed in the middle of the dense phase portion having a height of 1/2 or less of the inch reactor. The aperture ratio of the lattice was 81%.

All the gas flowing out of the reactor was passed through a condenser and the condensed liquid was analyzed by gas chromatography. Reaction temperature 336 ° C, linear velocity of raw material gas in reactor 5
At cm / sec, the phenol conversion was 83.7%.
The results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 1, the reaction was carried out by removing the grid of the reactor. When the reaction temperature was 332 ° C., the raw material gas linear velocity in the reactor was 5 cm / sec, and the production ratio of orthocresol and 2,6-xylenol was the same as in Example 1, the phenol conversion rate was 73.6%. .. The results are shown in Table 1.

Example 2 In the same manner as in Example 1, reaction was carried out by disposing grids of the reactor in the dense phase portion at three locations at substantially equal intervals. When the production ratio of orthocresol and 2,6-xylenol was the same as in Example 1 at a reaction temperature of 333 ° C. and a raw material gas linear velocity of 5 cm / sec in the reactor, the phenol conversion rate was 82.8%. The results are shown in Table 1.

Example 3 In the same manner as in Example 1, the reaction was carried out by setting the lattice of the reactor in the dense phase portion at five locations at substantially equal intervals. When the production ratio of orthocresol and 2,6-xylenol was the same as in Example 1 at a reaction temperature of 333 ° C. and a raw material gas linear velocity of 5 cm / sec in the reactor, the phenol conversion rate was 82.8%. The results are shown in Table 1.

[0032]

[Table 1]

[Brief description of drawings]

FIG. 1 is a graph showing a correlation between a production ratio of orthocresol and 2,6-xylenol and a phenol conversion rate.

FIG. 2 is an explanatory diagram showing a relationship between a catalyst rich phase in a reactor and an insert (lattice).

FIG. 3 is a partial perspective view of a reactor for explaining an opening ratio of an insert.・

Claims (1)

[Claims] 1. A method for producing an ortho-methylated phenol compound in which a phenol or / and ortho-cresol and methanol are subjected to a gas phase catalytic reaction in the presence of a metal oxide in a fluidized bed, and at least one or more of the inserts are horizontally placed. A method for producing an ortho-methylated phenol compound, which comprises using the provided reactor.