KR101070169B1 - A method for producing 2,6-dimethylphenol by methylation of phenol - Google Patents

Abstract

The present invention relates to a methylation catalyst of phenol and a process for producing 2,6-dimethylphenol under the catalyst, useful for producing 2,6-dimethylphenol by reacting phenol and methanol in a gas phase on a fixed bed catalyst.
More specifically, in the production of 2,6-dimethylphenol from phenol, the maximal suppression of by-products of alkylphenol compounds substituted with alkyl groups at meta or para positions of phenols such as meta-cresol, para-cresol and 2,4-dimethylphenol And a highly selective ortho-regioselective alkylation catalyst which is excellent in activity and long term reaction stability and a process for preparing 2,6-dimethylphenol under said catalyst.

Description

Method for producing 2,6-dimethylphenol by methylation of phenol {A METHOD FOR PRODUCING 2,6-DIMETHYLPHENOL BY METHYLATION OF PHENOL}

The present invention relates to a methylation catalyst of phenol and a process for producing 2,6-dimethylphenol under the catalyst, useful for producing 2,6-dimethylphenol by reacting phenol and methanol in a gas phase on a fixed bed catalyst.

More specifically, in the production of 2,6-dimethylphenol from phenol, the maximal suppression of by-products of alkylphenol compounds substituted with alkyl groups at meta or para positions of phenols such as meta-cresol, para-cresol and 2,4-dimethylphenol And a highly selective ortho-regioselective alkylation catalyst which is excellent in activity and long term reaction stability and a process for preparing 2,6-dimethylphenol under said catalyst.

2,6-dimethylphenol is mainly used as a monomer to produce polyphenylene oxide or polyphenylene ether, and is used as a raw material for fine chemical intermediates including antioxidants. Polyphenylene oxide is an engineering plastic widely used in the fields of electricity, electronics, automobiles, industrial materials, food containers or packaging.

In order to use 2,6-dimethylphenol as a monomer of polyphenylene oxide, a high-purity product is required, but since the requirements cannot be satisfied from natural cresols, most of the compounds are manufactured by synthetic methods. At this time, the boiling point of the by-product meta-cresol and para-cresol (hereinafter referred to as "m, p-cresol") is almost the same as 203 ° C, which is the boiling point of 2,6-dimethylphenol at 202 ° C and 203 ° C, Therefore, it is impossible to purify by simple distillation operation. Therefore, in order to prepare high purity 2,6-dimethylphenol, the by-product of m, p-cresol should be minimized in the methylation reaction of phenol, and for this purpose, the methylation catalyst should have high selective reaction characteristics.

 Moreover, in order to reduce the load of a purification process, it is preferable to suppress the by-product of 2, 4- dimethyl phenol (b.p = 211-212 degreeC).

 In addition, in order to obtain most of 2,6-dimethyl phenol which is the target compound of the present invention in the methylation reaction of phenol, it is necessary to operate under reaction conditions in which the conversion rate is kept high. In this case, 2,6-dimethyl phenol is the target compound. As the sequential hypermethylation reaction proceeds, 2,4,6-trimethylphenol and 2,3,6-trimethylphenol (hereinafter referred to as "trimethyl phenol = TMP") are produced. In order to obtain selectively, a catalyst capable of suppressing the hypermethylation reaction is more effective.

On the other hand, impurities contained in 2,6-dimethylphenol cause problems of deteriorating the quality of the polyphenylene oxide polymerized using 2,6-dimethylphenol as a monomer or reducing the activity of the polymerization catalyst. Japanese Laid-Open Patent Publication No. 1999-286542 discloses other alkyl phenols (o-cresol, o-ethylphenol, m in 2,6-dimethylphenol in the process of producing polyphenylene oxide using 2,6-dimethylphenol as monomer. -By adjusting the content of cresol, p-cresol, 2,4,6-trimethylphenol, etc. to less than 0.3% by weight, the activity of the polymerization catalyst is improved, thereby minimizing the use of a solvent for the removal of catalyst residues in the polymer. Therefore, it is proposed that the cost of recovering the polymers can be reduced by miniaturization of the catalyst removal equipment and the simplification of the removal process, thereby realizing the productivity of the polymerization process.

In WO 2003/01450, moreover, in order to improve the polymerization activity of 2,6-dimethylphenol and to achieve high molecular weight of polymer polyphenylene oxide and to improve the quality (especially color tone), among the impurities, m-cresol A composition having a content of 15 to 700 ppm, more preferably 15 to 100 ppm, based on the weight of 2,6-dimethylphenol, has been proposed. When 2,6-dimethylphenol in the composition range is used, 2,6-dimethylphenol is used. It demonstrates that the polymerization activity of the remarkably improves and the color tone improvement effect of the polyphenylene oxide which is a polymer is remarkable.

That is, this fact is that when the methylation reaction product of phenol is purified by distillation, m-cresol has a selectivity of 2,6-dimethylphenol in order to obtain a m-cresol-containing 2,6-dimethylphenol composition of 100 ppm or less. This means that a highly selective catalyst produced at 0.01% by weight or less relative to 6-dimethylphenol is required.

The technique known so far as a methylation catalyst for synthesizing 2,6-dimethylphenol and o-cresol is a catalyst based on magnesium oxide (MgO) (USP 5,371,306, USP 4,661,638, USP 4,554,266, USP 4,418,224, USP). 4,876,398, PL 159,203, PL 170,672, WO 2003 031,057, EP 785,180, Korean Patent No. 100558); Iron (Fe) -vanadium (V) oxide based catalysts (JP 2006 232,759, JP 2005 029,518, JP 1998 113,561, CS 270,694); Manganese oxide based catalysts (JP 1994 025,041, JP 1985 218,345, USP 4,661,638); Cobalt-ferrite type (CoFe ₂ O ₄ ) catalyst (USP 2001 005,769); And alumina (Al ₂ O ₃ ), Y-zeolitic acid catalysts (USP 5,276,215, JP 93 97,737).

Industrially, however, magnesium oxide catalysts and iron-vanadium catalysts are used. Although each catalyst is used commercially, there are problems to be improved in terms of reaction conditions, catalyst life, and the like. For example, magnesium oxide catalysts are operated at high temperatures of 350 ° C. or higher, preferably 370-450 ° C., but have low per pass conversion and low selectivity for 2,6-dimethylphenol, while iron-vanadium-based catalysts. The catalysts can be operated at lower temperatures than magnesium oxide catalysts, but they are operated in a fluidized bed reactor with a catalyst regeneration system because the catalysts are easily deactivated. If the iron-vanadium-based catalyst is operated in a fixed bed reactor, the catalyst must be regenerated at any time, which causes problems in using it as an industrial catalyst.

In particular, the inventors of the present invention, while studying a catalyst for producing 2,6-dimethylphenol by reacting phenol with methanol, found that there is a fatal weakness in utilizing a catalyst mainly composed of iron and vanadium as an industrial catalyst. That is, the reactant phenol or the product alkylphenol (o-cresol and 2,6-dimethylphenol, trimethyl phenol, etc.) can produce polymers of thermally very stable poly (alkyl) phenols, which are formed on the catalyst during the reaction. Since these polymer materials are carbonized to form coke or tar, the catalyst deactivation proceeds very quickly. In addition, in the above reaction, the coke generated on the catalyst not only deteriorates the catalytic activity, but also swells the catalyst particles, so that the reactor may be blocked by the expanded catalyst particles covered with the coke during a long operation. This made it impossible to operate for a long time in the form of a fixed bed reaction.

Therefore, in order to improve the above problems, the present inventors mix an appropriate amount of an inorganic binder component with a catalyst component composed of a crystalline iron vanadate compound having a weak cohesion force between particles, and further, cobalt na having a hydrogenation ability. In a catalyst having a composition improved with at least one of the nickel components, the catalyst particles were molded into a hollow cylinder, and the reaction was carried out in a reducing atmosphere, particularly in a reducing atmosphere under a gas stream containing hydrogen. At the time, the catalyst activity and long-term reaction stability have been found to be significantly improved and a patent has been filed for the above technology. (Korean Patent No. 891090) In addition, in the catalyst component composition of the patent, such as silicon carbide, silicon nitride, etc. Addition of whiskers, improvement of components, and formation of catalyst particles formed by coking during the reaction A patent has been filed for the preparation of o-cresol and 2,6-xylenol (= 2,6-dimethylphenol) by alkylation of more industrially available phenols with increased swelling. Korean Patent Application No. 2008-0106033)

However, the above-mentioned patents disclose that the target compounds of the reaction are o-cresol and 2,6-dimethylphenol, and in order to obtain only selectively the target compound 2,6-dimethylphenol targeted by the present invention for a long time, as described above, m, There is a need for a technique for producing 2,6-dimethylphenol under an improved catalyst that maintains long-term activity while inhibiting the by-product of p-cresol and 2,4-dimethylphenol and hypermethylation to TMP. There is room for improvement.

Accordingly, an object of the present invention is to react phenol and methanol in a gas phase process in a fixed bed reactor to continuously produce 2,6-dimethylphenol with high selectivity and high yield for a long time, under reaction conditions to maintain high conversion. In addition, the ortho-position-selective methylation catalyst having excellent selectivity and durability, in particular, the effect of suppressing the production of by-products substituted with methyl groups in the meta and para positions of phenols such as m, p-cresol and 2,4-dimethylphenol is remarkable. The present invention provides an efficient method for preparing 2,6-dimethylphenol.

In order to achieve the above object, the present invention provides a catalyst having a composition represented by the following formula (1):

[Formula 1]

In _a Fe _b V ₁ O _x (A) M 2 (B)]

In Formula 1,

Catalyst components such as In, Fe, and V exist in an oxide state,

a and b represent the atomic ratio of each component of In and Fe based on the composition 1 of V, a is 0.05-1.0, b is 0.05-1.0,

x is a number determined according to the values of a, b and the oxidation states of In, Fe, and V components based on the composition 1 of the vanadium component,

M 2 represents at least one component selected from silicate, aluminate or aluminum silicate compounds of alkaline earth metals.

In addition, the present invention provides a catalyst having a composition represented by the following general formula (2):

[Formula 2]

In _a Fe _b V ₁ M1 _c O _x (A) M2 (B)]

In Chemical Formula 2,

Catalyst components such as In, Fe, V, and M1 exist in an oxide state,

M1 represents at least one component selected from the group consisting of cobalt (Co), nickel (Ni), manganese (Mn), molybdenum (Mo), zinc (Zn), bismuth (Bi) and chromium (Cr),

a, b, and c represent the atomic ratios of the In, Fe, and M1 components based on the composition 1 of V, a is 0.05 to 1.0, b is 0.05 to 1.0, and c is 0 to 0.5,

x is a number determined according to the values of a, b, c and the oxidation states of In, Fe, V, and M1 components based on the composition 1 of the vanadium component,

M 2 represents at least one component selected from silicate, aluminate or aluminum silicate compounds of alkaline earth metals.

In Formulas 1 and 2, A and B represent weight%, A is an oxide catalyst of iron, an indium-vanadate composition, or an oxide catalyst improved with one or more components selected from the M1 component group in the iron, indium-vanadate composition. % By weight, having a value of 70-99, B is a weight% of at least one component selected from silicate, aluminate or aluminum silicate compounds of alkaline earth metals.

In addition, in order to achieve the above object, the present invention, in the reaction of phenol and methanol under the catalyst represented by the formula (1) or 2, characterized in that the reaction under a reducing atmosphere containing steam and hydrogen, in particular, steam and hydrogen It provides a method for producing 2,6-dimethylphenol.

According to the present invention, when the catalyst of the present invention was used to obtain 2,6-dimethylphenol from phenol and the methylation reaction was carried out under the flow of steam and hydrogen-containing gas, it showed excellent catalytic activity and long-term reaction stability. This means that the methylation reaction of phenol in commercial processes can be carried out under mild operating conditions, in a gas phase reaction in a fixed bed reactor, and high selectivity and high yield of 2,6-dimethylphenol without the occasional reactivation of the catalyst It can be manufactured stably for a long time. In addition, the improvement effect of inhibiting the formation of by-products such as m, p-cresol or 2,4-dimethylphenol and TMP in the methylation reaction product of phenol is remarkable, and the post-refining process for obtaining high quality 2,6-dimethylphenol is distilled. It is possible to operate only by the operation, and also to simplify the purification process greatly, thereby achieving high efficiency productivity.

Hereinafter, the present invention will be described in detail.

The present inventors investigated various metal-vanadate catalyst activity to overcome the disadvantages of Fe-V catalyst to obtain 2,6-dimethylphenol as the main product in the phenolalkylation reaction. While showing similar activity as the iron-vanadate catalyst, it was found that the long-term reaction stability is excellent. Moreover, the methylation reaction activity was dramatically increased in the catalyst containing the iron component in the indium-vanadate or the indium component in the iron-vanadate, and the hypermethylation reaction was significantly suppressed even at a high conversion rate, resulting in 2,6- It has been found that the selectivity of dimethylphenol is high and the durability is significantly improved. Furthermore, a catalyst improved with an indium component in iron-vanadate or a catalyst in which an indium, iron-vanadate composition is improved with one or more components of the formula M1 is selected from silicate, aluminate or aluminum silicate compounds of alkaline earth metals as the M2 component. The addition of one or more components further improves the selectivity of 2,6-dimethylphenol and significantly inhibits the by-products of m, p-cresol and TMP over catalyst systems that do not contain M2, and also provides 2,6-dimethyl in harsh temperature conditions. The present invention was found to have an effect of improving the by-products of by-products compared to phenols, and completed the present invention.

In the catalyst of Formula 1 or 2 according to the present invention, when the composition of V is 1, In has a composition of 0.05 to 1.0, preferably 0.07 to 0.9 atomic ratio, and when it is lower or higher than this, catalytic activity and selectivity are inferior. Fe has a composition of 0.05 to 1.0, preferably 0.1 to 0.95 atomic ratio when the composition of V is 1, and when it is lower or higher than this, the catalytic activity is low or the selectivity is inferior. The sum of the atomic ratios of In and Fe is preferably a catalyst having a composition close to the 1: 1 atomic ratio based on the V component amount in terms of activity and selectivity.

The catalyst of the composition is remarkably superior in the reaction activity to 2,6-dimethylphenol, compared to the existing iron-vanadate catalyst, and the catalyst according to the composition, including the M1 component, can exhibit more improved catalytic properties Can be. The M 1 component represents one or more components selected from the group consisting of cobalt (Co), nickel (Ni), manganese (Mn), molybdenum (Mo), zinc (Zn), bismuth (Bi) and chromium (Cr), and V When the composition of is 1, 0 to 0.5, preferably has a value in the range of 0 to 0.25 atomic ratio. When higher than the said range, catalytic activity and selectivity will become low.

The catalyst according to the present invention is an iron, indium-vanadate oxidizing composition catalyst and an iron, indium-vanadate oxidizing composition in the composition improved by at least one component selected from the M1 component group of formula (2) silicate or aluminate or aluminum of alkaline earth metals The addition of at least one component selected from the silicates further improves the selectivity of 2,6-dimethylphenol and maintains the selectivity of the catalyst even in more severe temperature conditions.

Alkaline earth metal in the present invention may be used beryllium, magnesium, calcium, strontium, barium and the like.

The alkaline earth metal silicate may be in various forms such as NSiO ₃ , N ₃ Si ₂ O ₇ , N ₂ SiO ₄ , depending on the ratio of NO: SiO ₂ (N is alkaline earth metal), but is not particularly limited to one compound. It may be a silicate composed of the above alkaline earth metal. Example: In case the alkaline earth metal is Ca: CaSiO ₃ , Ca ₂ SiO ₄ , CaSi ₂ O ₅ , Ca ₃ Si ₂ O ₇ , Ca ₃ SiO ₅ , CaBeSiO _4, Ca ₂ BeSi ₂ O ₇ Etc]

Alkaline earth metal aluminate may have various forms according to the ratio of NO: Al ₂ O ₃ (N is alkaline earth metal). [Example] When alkaline earth metal is Ca: CaAl ₂ O ₄ , Ca ₃ Al ₂ O ₆ , Ca ₂ Al ₂ O ₅ , Ca ₅ Al ₆ O _14, etc.], the aluminum silicate of alkaline earth metal may be in various forms depending on the ratio of NO: Al ₂ O ₃ : SiO ₂ (N is alkaline earth metal). In case of: CaAl ₂ Si ₂ O ₈ , Ca ₃ Al ₂ Si ₃ O ₁₂ , Ca ₃ Al ₆ Si ₂ O ₁₆ , CaAl ₂ SiO ₆ , Ca ₂ Al ₂ SiO _7, etc.] Not specifically limited to one compound The compound may be an alkaline earth metal aluminate or an alkaline earth metal aluminum silicate composed of two or more alkaline earth metals. EXAMPLE) such _{BaCa 2 Al 8 O 15, Ba} 5 CaAl 4 O 12, Ba 1 .4 SrCa 0 .6 Al 2 O 6]

More preferably, however, alkaline earth metal silicate compounds are effective, and still more preferably magnesium silicate or calcium silicate compounds. Since the catalyst according to the present invention includes at least one component selected from silicate, aluminate or aluminum silicate of alkaline earth metals, in addition to the effect of increasing the selectivity and activity of the catalyst, the catalyst is expressed as a more efficient and improved industrial catalyst in terms of reaction stability. . Specifically, there is an effect of inhibiting the volume expansion of the shaped particles by the formation of coke to ensure long-term reaction stability, and by controlling the catalytic activity per unit volume to alleviate the occurrence of local hot spots to inhibit run-away.

The silicate, aluminate or aluminum silicate compound (B) of the alkaline earth metal used in the catalyst according to the present invention is in powder form, and the particle size is preferably 50 mesh or less, more preferably 100 mesh or less. The catalyst parent component (A) in 1 and 2 may be mixed in powder form. In this case, at least one component (B) selected from silicate, aluminate or aluminum silicate of alkaline earth metal may be used in the range of 1 to 30% by weight, more preferably in the range of 5 to 20% by weight, based on the weight of the total catalyst composition. Can be used in If it is used in excess of this, the catalytic activity decreases, and if it is less than this, the use effect decreases.

In the catalyst of Chemical Formula 1 or 2 according to the present invention, the A component composition is preferably prepared by coprecipitation method. Dissolve together (solution A), and V is dissolved in V ₂ O ₅ or ammonium vanadate (NH ₄ VO ₃ ) by adding oxalic acid or monoethanolamine to deionized water (solution B), and the precipitant or neutralizing agent is Na, K, etc. Hydroxide, carbonate, bicarbonate, etc. may be used, but it is preferable to use ammonia water to simplify the cleaning process after the coprecipitation process. The catalyst may be prepared by the process of dropwise addition of solution A and solution B to deionized water at the same time or by coprecipitation by dropwise addition of solution A to solution B. Coprecipitation conditions are adjusted to be in the range of 0 to 100 ° C, preferably 10 to 60 ° C, and the pH of 5 to 11, preferably 6.5 to 9. Particularly, when the pH is low, the Fe component may be dissolved, and when the pH is high, the V component may be dissolved.

After coprecipitation, hydrothermal aging (ageing) for 2 to 12 hours at 50 ~ 90 ℃, washed, filtered. The cake obtained is dried and powdered, and uniformly mixed with one or more component powders selected from silicate, aluminate or aluminum silicate components of alkaline earth metals. Thereafter, the mixed powder is molded.

Molding can be made into powders in various forms (shapes) using a method such as tableting, and the shaped catalyst is subjected to calcination. The firing conditions are carried out in an air atmosphere in the range of 300 to 700 ° C, preferably 370 to 600 ° C.

The catalyst prepared by the above method is charged in a reactor, and the reaction mixture may be added by directly adding a mixed solution of phenol and methanol after raising the reaction temperature, but it is preferable to reduce the catalyst before supplying the reactant for fast stabilization at the beginning of the reaction. . The reduction process of the catalyst is carried out within 400 ℃, preferably 300 ~ 350 ℃ using a hydrogen / nitrogen mixed gas commonly used.

The reactants phenol and methanol are used in the molar ratio of methanol to phenol in the range of 1: 2 to 1: 8, preferably in the range of 1: 3 to 1: 6. At this time, water may be added to the reactants, and the amount of the additive is used at a molar ratio of 3 or less. The reaction temperature is 250 to 500 ° C, preferably 300 to 400 ° C, and the reaction pressure is operated at a normal pressure to 5 atmospheres, preferably at a normal pressure to 3 atmospheres.

The reaction may be carried out by supplying only a gaseous mixture of phenol, methanol and water on the catalyst, but it is essential to add a gas stream to keep the reactants and products in a gaseous state at all times within the reactor and to smoothly flow the reactants. At this time, inert gas such as nitrogen and argon can be supplied, but according to the present invention, it is effective to increase the catalyst life by maintaining a reducing atmosphere by supplying a gas containing hydrogen. The amount of hydrogen used is 5 to 100%, preferably 10% or more relative to the additional gas.

As described above, the catalyst having the composition of Formula 1 or 2 not only can significantly improve the catalytic activity and catalyst life when operating in the reaction conditions and the reaction atmosphere. Inhibit and significantly improve the yield and selectivity to 2,6-dimethylphenol. In addition, the activity and selectivity of the catalyst can be maintained for a long time even in more severe temperature conditions. This means that an improved indium, iron-vanadate catalyst can be used to industrially attempt the methylation of phenol in a fixed bed reaction process. In the phenol methylation reaction with 2,6-dimethylphenol as the main product, It improved the operation stability and drastically reduced the load of the subsequent purification process to improve the utility as an industrial catalyst. In addition, the catalyst deactivated by using for a long time can be repeatedly used by regeneration after decarbonization in the state filled in the reactor.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

[Example]

Example  One

Catalyst: In _(0.125) Fe _(0.875) V _(1.0) O _x [90 wt.%] / MgSiO ₃ [10% by weight]

<Catalyst preparation>

To 200 g of deionized water, 15.7 g of monoethanolamine and 30.0 g of NH ₄ VO ₃ were added, dissolved in warm water, and cooled to room temperature (solution B). Prepare a solution (solution A) in which 11.4 g of In (NO ₃ ) ₃ · 3H ₂ O and 85.5 g of Fe (NO ₃ ) ₃ · 9H ₂ O are dissolved in 300 g of deionized water, and then dropwise added while adjusting the pH. The co-precipitation process was performed. Thereafter, a diluted ammonia water solution was added to adjust the pH of the slurry solution to 7.0, followed by warming, followed by hydrothermal aging at 80 ° C. for 3 hours, followed by temperature reduction, filtration and washing. The cake obtained was dried at 120 ° C. for 12 hours. The completely dried cake was powdered to give Powder A.

MgSiO ₃ (Aldrich, Florisil; Magnesium silicate fine powder) powder was added to 90% by weight of powder A, and crushed and mixed by a ball milling method.

After the mixed powder was molded by tableting, the obtained molded product was classified into 20 to 40 mesh, and then fired at 480 ° C. for 6 hours under an air atmosphere.

<Alkylation reaction>

4.0 g of the calcined catalyst was charged to a 1/2 ^kPa tubular reactor and reduced at 350 ° C. with 5% H ₂ / N ₂ . Thereafter, at a reaction temperature of 340 ° C. and atmospheric pressure, a continuous reaction was carried out while feeding a mixture of phenol: methanol: water = 1: 5: 1 m / m / m with H ₂ (600 ml / hr) at a rate of 6.4 ml / hr. Was performed. After 300 hours, the reaction was carried out at 345 ° C. to investigate the change in the reactivity of the catalyst as the reaction temperature increased.

The reaction results are shown in Table 1 below. The by-product amount of m, p-cresol was 100 ppm or less compared to 2,6-dimethylphenol, and the by-product amount of TMP was 2.0% or less.

In addition, there was little decrease in selectivity of 2,6-DMP or increase in by-product byproducts with increasing reaction temperature.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 340 100 97.22 0.02 0.008 0.01 1.856 240 340 100 97.30 0.02 0.007 0.01 1.767 360 345 100 97.18 0.01 0.006 0.02 1.852

Example  2

Catalyst: In _(0.125) Fe _(0.825) Co _(0.05) V _(1.0) O _x [90 wt.%] / MgSiO ₃ [10% by weight]

<Catalyst preparation>

To 200 g of deionized water, 15.7 g of monoethanolamine and 30.0 g of NH ₄ VO ₃ were added, dissolved in warm water, and cooled to room temperature (solution B). A solution of 11.4 g of In (NO ₃ ) ₃ · 3H ₂ O, 85.5 g of Fe (NO ₃ ) ₃ · 9H ₂ O, and 3.73 g of Co (NO ₃ ) ₂ · 6H ₂ O in 300 g of deionized water ( After preparing solution A), co-precipitation was performed by dropwise addition while adjusting pH. Subsequent catalyst preparation and alkylation reactions proceeded in the same manner as in Example 1.

The reaction results are shown in Table 2 below. The by-product amount of m, p-cresol was 70 ppm or less compared to 2,6-dimethylphenol, and the by-product amount of TMP was 1.8% or less.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 340 100 97.40 0.06 0.006 0.01 1.70 240 340 100 97.58 0.11 0.005 0.01 1.51 360 345 100 97.50 0.06 0.005 0.01 1.60

Example  3

Catalyst: In _(0.125) Fe _(0.825) Co _(0.05) Cr _(0.05) V _(1.0) O _x [90 wt%] / CaSiO ₃ [10 wt%]

<Catalyst preparation>

To 200 g of deionized water, 15.7 g of monoethanolamine and 30.0 g of NH ₄ VO ₃ were added, dissolved in warm water, and cooled to room temperature (solution B). 11.4 g of In (NO ₃ ) ₃ · 3H ₂ O, 85.5 g of Fe (NO ₃ ) ₃ · 9H ₂ O, and 3.73 g of Co (NO ₃ ) ₂ · 6H ₂ O, 5.1 g of Cr (NO ₃ ) After preparing a solution (solution A) in which ₂ · 4H ₂ O was dissolved in 300 g of deionized water, the co-precipitation process was performed by dropwise addition while adjusting the pH. Subsequent processes were performed in the same manner as in Example 1 to prepare a parent powder, and then CaSiO ₃ [Wallastonite CaO (45.12) SiO ₂ (50.68) fine powder, not more than 200mesh after pulverization] The catalyst was prepared using the same method and conditions as in Example 1, and then subjected to the alkylation reaction in the same manner.

The reaction results are shown in Table 3 below. The by-products of m, p-cresol were 120 ppm or less compared to 2,6-dimethylphenol, the TMP by-product was 2.0% or less, and the long-term reaction stability of the catalyst was also excellent.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 340 99.99 97.28 0.10 0.011 0.01 1.87 240 340 99.99 97.44 0.12 0.008 0.01 1.70 1500 343 99.99 97.57 0.40 0.007 0.01 1.42

Example  4

Catalyst: In _(0.125) Fe _(0.825) Co _(0.05) V _(1.0) O _x [90 wt%] / MgAl ₂ O ₄ [10 wt%]

After preparing the same parent powder as in Example 2, MgAl ₂ O ₄ (High purity chemical company product, after the grinding 200mesh or less) to prepare a catalyst and the post-treatment in the same method and shipbuilding as in Example 1, the alkylation reaction was carried out in the same manner.

The reaction results are shown in Table 4 below, and the by-product amount of m, p-cresol was 140 ppm or less compared to 2,6-dimethylphenol.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 340 100 96.71 0.03 0.013 0.01 2.26 240 340 100 96.94 0.02 0.012 0.01 2.05 360 345 100 96.59 0.04 0.013 0.01 2.47

Comparative example  One

Catalyst: Fe _(1.0) Co _(0.05) V _(1.0) O _x

The composition catalyst was prepared in the same manner as in Example 1, and the phenol methylation reaction was performed under the same method and conditions except that the reaction temperature was 345 ° C.

The reaction results are shown in Table 5 below. The by-product amount of m, p-cresol was 350 ppm or more compared to 2,6-dimethylphenol, and the TMP by-product was 3.4% or less.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 345 99.97 91.49 3.14 0.035 0.05 3.05 240 345 96.53 63.71 33.05 0.025 0.17 1.83 360 350 99.96 95.29 1.19 0.027 0.05 2.48

Comparative Example 2

Catalyst: In _(0.125) Fe _(0.825) Co _(0.05) V _(1.0) O _x [99 weight%] / MgO [1 weight%]

A magnesium acetate (Mg (CH ₃ COO) ₂ .4H ₂ O) solution corresponding to 1% by weight of magnesium oxide was added to the catalyst mother powder (A) of Example 1, mixed uniformly, and dried and tableted. Thereafter, the mixture was worked up under the same conditions and methods as in Example 1, and the methylation reaction of phenol was performed at 345 ° C.

The reaction results are shown in Table 6, and when the catalyst was directly improved with alkaline earth metal components, the catalytic activity decreased drastically and the by-product amount of 2,4-DMP increased rapidly.

Reaction time (hr)
Reaction temperature
(℃)
Phenolic Conversion Rate (%)
Selectivity 2,6-dimethylphenol (%) o-cresol (%) m, p-cresol (%) 2,4-dimethylphenol (%) Trimethylphenol (%) 120 345 94.48 66.10 31.03 0.015 0.14 1.73 240 345 86.61 34.13 63.26 0.008 0.80 0.92

Claims (16)

An alkylation catalyst of phenol, represented by the following general formula (1):
[Formula 1]
In _a Fe _b V ₁ O _x (A) M 2 (B)]
In Chemical Formula 1,
Catalyst components such as In, Fe, and V exist in an oxide state,
a and b represent the atomic ratio of each of In and Fe components based on the composition 1 of V, a is 0.05-1.0, b is 0.05-1.0,
x is a number determined according to the values of a, b and the oxidation states of In, Fe, and V components based on the composition 1 of the vanadium component,
M2 represents silicate, aluminate or aluminum silicate of alkaline earth metals, A and B are in weight percent, A has a value in the range of 70 to 99, and B has a value in the range of 1 to 30. An alkylation catalyst of phenol, represented by the following formula (2):
(2)
In _a Fe _b V ₁ M1 _c O _x (A) M2 (B)]
In Chemical Formula 2,
Catalyst components such as In, Fe, V, and M1 exist in an oxide state,
M1 represents at least one component selected from the group consisting of cobalt (Co), nickel (Ni), manganese (Mn), molybdenum (Mo), zinc (Zn), bismuth (Bi) and chromium (Cr),
a, b, and c represent the atomic ratios of the In, Fe, and M1 components based on the composition 1 of V, a is 0.05 to 1.0, b is 0.05 to 1.0, and c is 0 to 0.5,
x is a number determined according to the values of a, b, c and the oxidation states of In, Fe, V, and M1 components based on the composition 1 of the vanadium component,
M2 represents silicate, aluminate or aluminum silicate of alkaline earth metals, A and B are in weight percent, A has a value in the range of 70 to 99, and B has a value in the range of 1 to 30. The catalyst according to claim 1 or 2, wherein a is 0.07 to 0.7. The catalyst according to claim 1 or 2, wherein the parent component (A) of the catalyst is in the range of 75 to 95% by weight and the M2 component (B) is in the range of 5 to 25% by weight. The catalyst according to claim 1 or 2, wherein M2 is at least one selected from silicate, aluminate or aluminum silicate of alkaline earth metals. 6. The catalyst of claim 5 wherein the silicate of the alkaline earth metal is magnesium silicate or calcium silicate. The catalyst according to claim 1 or 2, wherein the catalyst is for producing 2,6-dimethylphenol by methylation of phenol. A method for producing 2,6-dimethylphenol comprising reacting phenol and methanol,
A reaction method comprising reacting the phenol and the methanol-containing reaction in a gaseous state under a flow of hydrogen-containing gas on the catalyst according to claim 1. 9. A process according to claim 8 wherein the catalyst is reduced before feeding the reactants. 9. The production process according to claim 8, wherein the phenol: methanol = 1: 2 to 1: 8 molar ratio. The production method according to claim 8, wherein the reaction temperature is 250 to 500 ° C. The method of claim 9, wherein the reduction of the catalyst is carried out at 300 ~ 400 ℃ using a hydrogen / nitrogen mixed gas. The production method according to claim 8, wherein the reaction pressure is carried out at normal pressure to 3 atmospheres. 9. The process according to claim 8, wherein water is added to the reactants containing phenol and methanol. 15. The process according to claim 14, wherein water is added in an amount of 3 molar ratio or less based on phenol. The method according to claim 8, wherein after the reaction, the catalyst is regenerated and repeatedly used by a decarbonization process under a flow of air in a state filled with a reactor.