KR100582092B1 - The method of activated carbon catalysts for Phenol synthesis and the Synthetic method of Phenol through its catalysts - Google Patents

Abstract

The present invention relates to an activated carbon catalyst for synthesizing phenol, a method for preparing the same, and a method for synthesizing phenol using the same, and an object thereof is to enable direct conversion of benzene to phenol, and to have an excellent phenol yield, thereby separating and byproducts. The present invention provides an activated carbon catalyst for synthesizing phenol, a method for preparing the same, and a method for synthesizing phenol using the same, which may reduce treatment costs and reduce energy consumption in a process.

The present invention provides activated carbon for phenol synthesis, which can directly synthesize phenol from benzene by using a activated carbon as a support and supporting a transition metal selected from the group consisting of titanium, cobalt, manganese, nickel, iron, copper, and vanadium. It provides a catalyst, a method for preparing the same, and a method for synthesizing phenol using the same.

Phenol synthesis, hydroxylation, activated carbon, acid treatment, heat treatment, transition metal

Description

The method of activated carbon catalysts for Phenol synthesis and the Synthetic method of Phenol through its catalysts}

1 is an acid treatment process chart of activated carbon according to the present invention.

Figure 2 is an exemplary view showing the phenol yield of the activated carbon catalyst supported on the transition metal in accordance with the present invention

3 is an exemplary view showing benzene conversion and phenol selectivity according to the amount of vanadium supported in the present invention.

4 is an exemplary view showing a phenol yield according to the amount of vanadium supported in the present invention

5 is an exemplary view showing another benzene conversion rate and phenol selectivity in the iron loading of the present invention

6 is an exemplary view showing a phenol yield according to the iron loading of the present invention

7 is an exemplary view showing a phenol yield according to the amount of solvent added to the vanadium / iron catalyst according to the present invention

8 is an exemplary view showing benzene conversion and phenol selectivity according to the activated carbon catalyst of the present invention in an acetonitrile solvent.

9 is an exemplary view showing a phenol yield according to the activated carbon catalyst of the present invention in an acetonitrile solvent

10 is an exemplary view showing the benzene conversion rate and phenol selectivity of the present invention iron-supported activated carbon catalyst

11 is an exemplary view showing the phenol yield of the iron-supported activated carbon catalyst of the present invention

The present invention relates to a method for preparing an activated carbon catalyst for phenol synthesis and a method for preparing a phenol using the same, wherein when direct synthesis of benzene to phenol is carried out through a catalyst having a transition metal supported on activated carbon having a high specific surface area and porosity, It relates to a method for producing activated carbon catalyst for phenol synthesis and a method for producing phenol using the same, which can obtain a high phenol yield.

In general, phenol is an important intermediate and final material in the chemical industry, producing 2.4 million tonnes in 2001. 80% of its production is produced through the oxidation of cumene, called hawk proeds. The remainder is produced by the oxidation process of toluene. In the hawk process, phenol is produced in a multi-step process. As a final product, phenol and acetone are obtained in equimolar moles, but acetone has excellent properties as a solvent, but market demand is not greater than that of phenol. On the other hand, in the toloene process, phenol is produced through benzoic acid, but there is a problem in low phenol yield. In addition, the existing commercialization process is made of a multi-stage process as described above, the problem of energy consumption and by-product treatment occurs.

In order to solve this problem, the development of a process in which fewer by-products are produced in one step without going through various steps, ie, gas phase oxidation reaction using nitrous oxide, oxygen and air as oxidant, hydrogen peroxide, oxygen, air A study on the direct conversion of benzene to phenol through the liquid phase oxidation reaction has been actively conducted. The catalysts mainly used in this liquid phase reaction include a copper-supported zeolite catalyst, a copper-substituted hollow pore silicate and alumina. A nosilicate catalyst, a heteropolyacid catalyst encapsulated in MCM-41 and VPI-5, a doubling catalyst supported on silica, and a vanadium catalyst supported on alumina are used.

The present invention has been made in view of the above problems, and its object is to allow direct conversion of benzene to phenol, and to have an excellent phenol yield, thereby reducing the cost of separation and treatment of by-products, and injecting them into the process. It is to provide a method for preparing an activated carbon catalyst for phenol synthesis and a phenol synthesis method using the same, which can reduce energy consumption.

The present invention relates to a catalyst used in the direct hydroxylation reaction of benzene to phenol and a method for producing phenol using the same. The present invention provides an activated carbon catalyst supporting a transition metal with activated carbon as a support, and under the catalyst Benzene, oxidant and solvent are mixed in a proportion to synthesize phenol directly from benzene.

The activated carbon catalyst is prepared by impregnation using a rotary evaporator. As the transition metal, titanium, cobalt, manganese, nickel, iron, copper, vanadium is used, and preferably iron, copper, vanadium.

That is, metal precursors (copper; copper acetate monohydrate, iron; iron nitrate monohydrate, vanadium; vanadyl acetylacetonate, etc.) are dissolved in water, placed in a rotary evaporator, impregnated in activated carbon, dried in an 80 ° dryer, and dried for one day. Firing at 550 ° C. under an atmosphere for 5 hours to prepare an activated carbon catalyst having a transition metal supported thereon. In this case, since the activity does not change in size at 550 ° C. or higher, the catalyst is calcined while maintaining the temperature.

In addition, the activated carbon may be activated carbon subjected to acid treatment or acid treatment and heat treatment. That is, as shown in FIG. 1, 5M nitric acid (HNO ₃ ) is added to activated carbon (Norit AC) and refluxed near the break point of 60 ° C. to 70 ° C. nitric acid for 4 hours, and then 80 Activated carbon (NACH) treated with a certain amount of nitric acid by drying at or above ℃ can be used. In addition, activated carbon treated with nitric acid under a nitrogen atmosphere at 600 ° C. to 1100 ° C. may be used as a support.

The present invention is intended to directly synthesize phenol by reacting benzene and hydrogen peroxide under the above activated carbon catalyst. In this case, since the mixture of benzene and hydrogen peroxide does not mix well with water contained in a large amount of benzene and hydrogen peroxide, acetone or acetonitrile is further added thereto to uniformly mix benzene and hydrogen peroxide, and the mixed solvent is benzene. The molar ratio (benzene: solvent) of 1: 4.65-1: 6.58 is maintained on the basis of. A relatively large amount of solvent causes the reactant mixture to be diluted, thereby restricting access to the catalytically active site. Therefore, since the amount of the solvent has a greater influence on the reaction, the mixing ratio of the reactants benzene, hydrogen peroxide and acetonitrile was controlled by limiting the molar ratio of benzene and solvent.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and examples.

Example 1

Titanium, cobalt, manganese, nickel, iron, copper and vanadium precursors are dissolved in water and then placed in a rotary evaporator and impregnated with activated carbon.Then, they are placed in an 80 ° C dryer and dried for 24 hours, and then at 550 ° C for 5 hours under nitrogen atmosphere. By firing, an activated carbon catalyst having 0.5 wt% of titanium, cobalt, manganese, nickel, iron, copper, and vanadium supported on activated carbon is prepared.

Phenol direct synthesis experiment from benzene was used in the SUS reactor, the reactant and the activated carbon catalyst loaded with the 0.5wt% transition metal is completely mixed using a magnetic stirrer. At this time, the reaction was carried out for 5 hours at 65 ℃, the reactant is composed of benzene as the main raw material, 30% hydrogen peroxide and a solvent as an oxidizing agent, the reactants are benzene, acetonitrile as a solvent, hydrogen peroxide as an oxidizing agent 1: 1: 6.0. The mixture was tested by mixing in a molar ratio of. Also, 0.1 g of the catalyst was used, and the reaction product was analyzed by HPLC (Waters 2690) equipped with a C18 column and a UV detector (wavelength: 254 nm). The mobile phase of LC was mixed at a composition of 42 vol% water and 58 vol% acetonitrile and flowed at 1.0 ml / min.

The result of phenol yield by the activated carbon catalyst loaded with the transition metal as described above is shown in FIG. 2, and it can be seen that iron, copper, and vanadium have better reaction characteristics than other transition metals. .

Example 2

After dissolving vanadium precursor material (vanadyl acetylacetonate) in water and putting it in a rotary evaporator, it was impregnated in activated carbon, and dried in an 80 ° C. dryer for one day, and then calcined at 550 ° C. for 5 hours under a nitrogen atmosphere. , Activated carbon catalyst supported on activated carbon at 1.0wt%, 2.0wt%, 5.0wt%. Phenol direct synthesis experiments and reaction products from benzene are the same as in Example 1.

Figure 3 is an exemplary view showing the benzene conversion and phenol selectivity according to the vanadium supported amount of the present invention, Figure 4 shows an exemplary view showing the phenol yield according to the vanadium supported amount of the present invention, vanadium 5.0wt% supported catalyst It can be seen that the phenol yield of about 13% is obtained.

Example 3

Iron nitrate monohydrate was dissolved in water and then placed in a rotary evaporator, impregnated in activated carbon, and then dried in an 80 ° C. dryer for one day, and then calcined at 550 ° C. for 5 hours under a nitrogen atmosphere. An activated carbon catalyst supported on activated carbon at%, 1.0wt%, 2.0wt%, 5.0wt% is prepared. Phenol direct synthesis experiments and reaction products from benzene are the same as in Example 1.

5 is an exemplary view showing different benzene conversion and phenol selectivity in the iron loading of the present invention, and FIG. 6 is an exemplary view showing the phenol yield according to the iron loading of the present invention. The results show that, in the case of a catalyst loaded with 5.0 wt% of iron, the yield of about 16% is higher than that of the phenol of the vanadium catalyst.

Example 4

7 is an exemplary view showing the phenol yield according to the solvent addition amount of the vanadium / iron catalyst according to the present invention, the activated carbon catalyst and 5.0 wt% iron supported on activated carbon with 5.0 wt% of vanadium according to Examples 2 and 3 Activated carbon supported on activated carbon was prepared, and 20.8 g of acetone, 14.7 g of acetonitrile, 20.8 g of acetonitrile, and 20.8 g of acetonitrile were added as a solvent during phenol direct synthesis experiment from benzene under the activated carbon catalyst. The reaction product was analyzed accordingly.

When acetonitrile was added 14.7 g (solvII), the highest reactivity was observed. When acetonitrile was added 14.7 g, iron showed higher phenol yield than vanadium, and acetonitrile 20.8 g ( solvIII) It can be seen that the vanadium catalyst has a higher yield than the iron catalyst.

Example 5

5M nitric acid is added to activated carbon and refluxed at 60 ° C. to 70 ° C. for 4 hours, and then dried at 80 ° C. or higher to prepare activated carbon treated with a certain amount of nitric acid. In addition, the activated carbon treated with nitric acid under nitrogen atmosphere was heat treated at 600 ° C, 750 ° C, and 1100 ° C. These were named as NACH-600N, NACH-750N, and NACH-1100N, respectively, and the benzene conversion rate of the activated carbon catalyst under acetonitrile solvent And phenol selectivity were examined and the results are shown in FIG. 8.

FIG. 8 shows an exemplary view showing benzene conversion and phenol selectivity according to the present invention activated carbon catalyst in acetonitrile solvent. The conversion of benzene was only slightly different, but no significant change was observed, but the selectivity of phenol was NACH. -600N was the highest observed.

The yield of phenol according to this result is as shown in FIG. Figure 9 shows an exemplary view showing the phenol yield according to the activated carbon catalyst of the present invention in acetonitrile solvent, it can be seen that the phenol yield under the activated carbon catalyst subjected to acid treatment, acid treatment and heat treatment.

Example 6

5M nitric acid was added to the activated carbon and refluxed at 60 ° C. to 70 ° C. for 4 hours, and then dried at 80 ° C. or higher to prepare activated carbon treated with a certain amount of nitric acid. Thus, nitric acid treatment under nitrogen atmosphere was performed. Activated carbon is heat-treated at 600 ° C., 750 ° C., and 1100 ° C. to produce activated carbon.

Iron nitrate monohydrate was dissolved in water and then placed in a rotary evaporator, activated carbon (A), acid treated activated carbon (B), acid treated and activated carbon (C) heat treated at 600 ° C., heat treated at 750 ° C. Activated carbon (D), benzene conversion and phenol selectivity of the activated carbon (E) catalyst heat-treated at 1100 ° C. were observed, and the results are shown in FIGS. 10 and 11. (Acetonitrile was used for the solvent at this time.)

10 is an exemplary view showing the benzene conversion rate and phenol selectivity of the iron-supported activated carbon catalyst of the present invention, Figure 11 is an illustration showing the phenol yield of the iron-supported activated carbon catalyst of the present invention, from the acid It can be seen that the activated carbon catalyst (C) loaded with 5 wt% iron treated and heat treated at 600 ° C. shows the best reactivity.

As in Examples 1 to 6, it can be seen that a high phenol yield can be obtained in the direct synthesis of benzene to phenol under a catalyst using activated carbon as a support of the transition metal, and acid treated the activated carbon used as a support Alternatively, when the acid treatment and heat treatment are performed, very good phenol yield can be obtained.

In addition, it can be seen that the phenol yield can be improved when the amount of the transition metal supported and the molar ratio of benzene and solvent are added under selected conditions.

Comparative Example 1

Direct conversion of benzene to phenol was carried out under a conventional zeolite catalyst, and benzene conversion, phenol selectivity, and yield thereof are shown in Table 1 below.

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As described above, it can be seen that the conventional zeolite catalyst is represented by 10% or less in terms of yield of phenol.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, the present invention is to use a transition metal supported catalyst having a high specific surface area and porous activated carbon as a support for direct synthesis of phenol, thereby broadening the field of application of activated carbon and saving energy input to the separation process in the existing process. High phenol yields can be obtained to meet the demand for phenol, the basic and intermediate product of chemicals.

In addition, through the pre-treatment and heat treatment of activated carbon, the optimum molar ratio of benzene and solvent can improve the phenol yield.

Claims (7)

delete delete A method for producing a catalyst used in the direct synthesis of benzene to phenol; The catalyst is dissolved in water, one transition metal precursor selected from the group consisting of titanium, cobalt, manganese, nickel, iron, copper, vanadium, put in a rotary evaporator, and impregnated in activated carbon, put it in a dryer for 24 hours at 80 ℃ After drying, firing is maintained at 550 ° C. under a nitrogen atmosphere. The activated carbon was added with 5M nitric acid and refluxed at 60 ° C. to 70 ° C. for 4 hours, dried at 80 ° C., and then heat-treated at 600 ° C. to 1100 ° C. Catalyst preparation method. delete Under the catalyst prepared by the method of claim 3, benzene and hydrogen peroxide are reacted, and acetone or acetonitrile is added to the benzene and hydrogen peroxide as a solvent, and the benzene and the solvent are added at a molar ratio of 1: 4.6 to 6.58. Phenol synthesis method using an activated carbon catalyst, characterized in that provided. delete delete

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