Method and catalyst for the purification of phenol

 

The invention relates to a process for the production of phenol Kukolnik method. Purification of phenol, obtained by the decomposition of gidroperekisi hydroperoxide and containing detachable hard at his distillation of impurities is carried out by contacting phenol with alumiinium a catalyst consisting of a mixture of aluminum oxide and zirconium oxide and sulphate of aluminum and zirconium at a temperature of 90-200^oC and space velocity of the feedstock 1-6 h^-1. The catalyst contains sulfates in the amount of 5-15 wt. % (in terms of ion SO₄), oxides of 5-30% (in terms of Al₂O₃). For the preparation of the catalyst, a mixture of boehmite and pseudoboehmite (ratio of from 1: 3 to 3: 1 by weight). Carry out the precipitation of the hydroxides of zirconium, and the above-mentioned mixture of hydroxides of aluminum, received mixed hydroxides of aluminum and zirconium, sulfation aqueous solution of sulfuric acid, peptizer also using an aqueous solution of sulfuric acid, after which produce a screw extrusion obtained catalyst mass and heat treatment of the extrudates. The technical result - the application aljumotsinkovanija catalyst results in high purity phenol free from impurities present in the phenol-circlee to the process of production of phenol and acetone Kukolnik method.

Raw phenol obtained by the decomposition of gidroperekisi hydroperoxide with an acid catalyst, does not meet consumer properties, because it contains admixtures of hydroxyacetone (HA), 2-methylbenzofuran (2-MBF), alpha-methylstyrene (AMS), acetophenone (AF), oxides of mesityl (Ω) and dimethylphenylcarbinol (DMPC) and needs to be cleaned from these impurities.

Relatively clean target phenol is obtained by fractional pickup of the product of decomposition of gidroperekisi cumene with separation from lower boiling and higher boiling components [U.S. Patent 4251325, 1978]. However, even when functioning properly rectifying node allocated phenol contains albeit relatively small, but potentially dangerous amounts of such impurities as HA and 2-MBF.

Known methods of purification of raw phenol impurities from the use of different heterogeneous catalysts, in which the above impurities become almost completely in high-boiling compounds, subject to further separation from the product of the phenol by distillation. The exception is HA, depending on the efficiency of the catalyst can turn into a 2-MBF or higher boiling products. Thus, in the course of the catalytic conversion of the>For example, a method of producing phenol of high purity by contacting the raw material phenol, obtained by decomposition of gidroperekisi cumene, with a heterogeneous catalyst comprising a gamma-alumina with a specific surface area and specific surface acidity centers. While aliphatic and aromatic carbonyl compounds present in the raw material phenol, into the high-boiling products, which are relatively easily separated from the desired product by the method of rectification [U.S. Patent 5264636, 1992]. The disadvantage of this method is not sufficiently high activity of the catalyst, especially when a relatively low content of impurities in the phenol-raw (to 0.15 wt.% or less), resulting in a low degree of decrease in the content of 2-MBF in the target product.

Closest to the proposed method according to the essential characteristics and the achieved result is a method of purification of phenol from by-products of the oxidation of cumene by processing the raw phenol in contact with a catalyst comprising an activated aluminosilicate, followed by the separation of the formed high-boiling components by the method of d is s synthetic acidic aluminosilicate catalyst amorphous or crystalline, or get out of the gel, or by acid treatment of aluminosilicate clays of the bentonite type.

The effective temperature of the cleaning process is 50-200^oWith that allows you to clean both in liquid and in the vapor phase. Thus the higher the catalyst activity and the higher the process temperature, the less contact time required to achieve the necessary degree of purification of phenol. However, during the operation of the catalyst gradually deactivated due to the deposition in the pores of those reaction products, which process temperatures are in the solid state. For regeneration of the catalyst has to be rinsed with purified phenol.

The disadvantage of this method of purification of phenol is also that present HA significantly (up to 80%) is converted to silica-alumina catalyst in difficult detachable from phenol 2-MBF.

The purpose of the present invention is the obtaining of phenol with high purity by making the impurities present in the raw material phenol produced by the decomposition of gidroperekisi cumene. This goal is achieved by treatment of phenol containing impurities of aliphatic and aromatic carbonyl is of xadow and sulfate of zirconium with a total content of the mixture of the sulfates of aluminum and zirconium (in terms of SO₄from 5 to 15 wt.% and with a total content of the oxide of aluminum sulfate from 5 to 30 wt.% (in terms of aluminum oxide).

The process is carried out at a temperature of 90-200^oWith and relative volumetric feed rate of raw materials from 1 to 6 h^-1. Received after contacting phenol with the proposed catalyst by distillation produce almost pure phenol.

Thus, there is a complete conversion contained in the raw material phenol impurities in high-boiling compounds which are easily separated from phenol, including HA no more than 30% is converted to 2-MBF.

A distinctive feature of the proposed method of purification of phenol is using aljumotsinkovanija catalyst comprising a mixture of oxides and sulfates of aluminum and zirconium at a given temperature process and a given volume relative feed rate of the raw material.

Use alumiinium catalysts for the purification of phenol is not known, which allows to conclude that the non-obviousness of this feature.

The present invention relates to a catalyst for purification of phenol and method of its preparation.

Usually alumina catalysts are prepared by precipitation of the hydroxide is ri 18-25^oWith so-called hot deposition at 100-102^oWith, and the resulting precipitates are mixed in different ratio that allows you to adjust the quality of the product. The precipitation mixture is washed with water from sodium nitrate, plastificator by evaporation and peptization and then the resulting mass is formed into not screw extruder into pellets of the desired size [Patent USSR 1559494, 1990; RF Patent 2058189, publ. in BI 11 20.04.96].

Aljumotsinkovanija catalysts used for other purposes, and not for the purification of phenol, prepared also by precipitation of zirconium hydroxide from a solution of circinelloides (ZrOCl₂8H₂O) ammonia solution, followed by drying of the resulting sludge and processing of 1 N. a solution of sulfuric acid. For forming granules of powder sulfated zirconium hydroxide is mixed with aluminum hydroxide, used as a binder [J. Catal., 153, 218-223 (1995)].

For example, there is a method of cooking aljumotsinkovanija catalyst for the isomerization of paraffin hydrocarbons [U.S. Patent 6326328, 2000 , the prototype]. At the specified method take a mixture of powders of hydroxides of zirconium and aluminium with the addition of sulfatides agent is a salt of ammonium sulfate, stirred, ekstragiruyut datirovany aluminum oxide.

However, the catalyst prepared according to the method prototype is not suitable for the purification of phenol, because it has less activity than the proposed method, and it does not provide the required clearance depth in relation to the content of 2-MBF in the finished product.

The method of preparation of the proposed composition of the catalyst for purification of phenol produced by the decomposition of gidroperekisi cumene, includes the stage of precipitation of hydroxides of aluminum and zirconium, sulfation hydroxides, peptization of the electrolyte solution, screw extrusion catalyst mass and heat treatment of the extrudates. As the source of aluminum compounds used aluminum hydroxide, consisting of boehmite and pseudoboehmite at mass ratio of 1:3-3:1 (in terms of aluminum oxide). As patinator use an aqueous solution of sulfuric acid, which is injected into the catalyst mass at the stage of sulfation and at the stage of peptization.

The essential features of the proposed method are the use of a mixture of boehmite and pseudoboehmite in the ratio indicated for the preparation of compositions, as well as the introduction of sulfuric acid in two steps: at the stage of sulfation and on stage peptization catalyst mass. None commodity phenol impurities in an easily detachable high-boiling compounds.

Methods of cooking alumiinium catalysts proposed composition is not known to us.

Industrial applicability of the proposed catalyst for the purification of phenol and method of its preparation is confirmed by the following examples.

Example 1.

a) Preparation of catalyst 431 g of salt ZrOCl₂8H₂O dissolved in 5.2 l of distilled water. To the resulting solution was poured dropwise within 20 minutes 332 ml NH₄OH with a concentration of about 25%. The precipitate is filtered off and washed with a Buechner funnel water from the ammonium chloride. Received the washed precipitate is dried in a drying Cabinet at 110^oWith in 24 hours. Dried sludge grind at the mill, and the obtained fine powder otsaila through sieve 180 μm. The mass of the powder was 190 g or 147 g in terms of ZrO₂.

Powder process for the sulfation of 1.14 l of 1 n sulfuric acid solution for 1 hour. Then the mixture is filtered from the excess solution, the product is dried at 110^o(10 hours) and then used for forming.

To obtain pseudoboehmite take 3 liters of sodium aluminate solution with a concentration of 100 g/l, the Deposition is carried out by simultaneous discharge in the range from 9.1 to 9.5 for 2 hours. After draining of fluids suspension is subjected to operation stabilization by boiling (102-105^o(C) at a constant pH in the range from 9.1 to 9.3 by the addition of sodium aluminate solution. Get the suspension vitreous sludge pseudoboehmite containing 300 g of Al₂About₃.

To obtain boehmite take 1 l of sodium aluminate solution with a concentration of 100 g/l, the Deposition is carried out by the simultaneous discharge of a specified aluminate solution and a 60% aqueous solution of nitric acid (flow rate 0.7 l) at a temperature of 102-105^oWith (at boiling), pH in the range from 8.5 to 8.9 for 2 hours. Get the suspension chalky sediment boehmite containing 100 g of Al₂About₃.

The resulting suspension of pseudoboehmite and boehmite are mixed and subjected to washing with a Buechner funnel from the impurity salt of sodium nitrate. The washed precipitate is dried for 10 hours at 110^oWith and grind into fine powder passing entirely through a sieve with the hole diameter of 0.25 mm Loss on ignition (SPT) at 850^oWith the obtained dried mixed powder of aluminum hydroxide make up 24.6 wt.%. The ratio of boehmite : pseudoboehmite powder of aluminum hydroxide in terms of Al₂About₃is 1:3.

Next, the powder sulfation is s, peptizer solution of sulfuric acid (3.8 ml of a 60% aqueous solution), add in small portions of about 250 ml of water, bringing humidity (SRR) weights to 55 wt. %. The resulting mass is molded on to the screw extruder through a die hole diameter of 2.0 mm extrudates are dried for 8 hours at a temperature of 110^oC, and then calcined in a flow of dry air for 4 hours at 630^oC.

The gross composition of the finished catalyst: 66,2 wt.% ZrO₂; 30 wt.%-Al₂About₃; 5.0 wt. % S. the Total content of sulfates of aluminum and zirconium in the catalyst in terms of SO₄made up 15.0%, the total content of the oxide and sulphate of aluminium in terms of Al₂About₃30 wt.%.

b) Purification of phenol Test obtained aljumotsinkovanija catalyst in the process of purification of phenol is carried out at a temperature of 110^oC and space velocity of the raw material (V)= 1.5 h^-1in running a laboratory setup. The following table shows the composition of the raw cumene produced by the decomposition of gidroperekisi cumene and to be cleaned, and the product of its catalytic purification on the prepared catalyst.

The content of impurities in the phenol was determined by gas chromatography is p>

The catalyst is prepared as in example 1, but the ratio of boehmite : pseudoboehmite (Al₂About₃in a mixed powder of aluminum hydroxide is 3:1. For sulfation precipitate of zirconium hydroxide take 380 ml solution of sulfuric acid. The number of mixed powder of aluminum hydroxide obtained for the mixing of powder sulfated zirconium hydroxide, equal to 13.9, Other parameters are the same as those in example 1.

The total content of sulfates of aluminum and zirconium in the obtained sample calcined (ready) catalyst in terms of SO₄amounted to 5.0 wt.%, the total content of the oxide and sulphate of aluminium in terms of Al₂O₃5 wt. %.

The test received aljumotsinkovanija catalyst in the process of purification of phenol is carried out at a temperature of 110^oC and space velocity of the raw material V=6.0 h^-1. Get a phenol containing mn^-1: HA<1, AMC<1, 2-MBF 50, OM<5, AF<1, DMFC<1.

Take a sample aljumotsinkovanija catalyst preparation and the composition of which is described in example 1. Tests carried out by the method described above at a temperature of 90^oC and space velocity of the feedstock 1.0 hour^-1. Get a phenol containing mn^-1: HA&the pressure and the composition of which is described in example 2. Tests carried out by the method described above at a temperature of 200^oC and space velocity of the feedstock 1.5 h^-1. Get a phenol containing mn^-1: HA<1, AMC<1, 2-MBF 31, OHM<5, AF<1, DMFC<1.

1. U.S. patent 4251325, 1978.

2. U.S. patent 5264636, 1992.

3. U.S. patent 2910511, 1956 (the prototype).

4. Patent USSR 1559494, 1990; RF Patent 2058189, 1996.

5. U.S. patent 6326328, 2000 (prototype).

Claims

1. The method of purification of phenol, obtained from the gidroperekisi of cumene from impurities aliphatic and aromatic carbonyl compounds by contacting phenol with an acid alumoxane catalyst at elevated temperature, followed by separation of the target product by distillation, characterized in that as alumoxane catalyst, a mixture of oxides and sulfates of aluminum and zirconium, with a total content of sulfates of aluminum and zirconium from 5 to 15 wt.% (in terms of ion SO₄and the total content of the oxide and aluminium sulphate 5-30 wt.% (in terms of aluminum oxide) and the process is carried out at 90-200When the volumetric feed rate of raw materials 1-6 h^-1.

2. Kata is arbonelli compounds, comprising a mixture of aluminum oxide and zirconium oxide promoted sulfate, when the total content of sulfates of aluminum and zirconium from 5 to 15 wt.% (in terms of ion SO₄and the total content of the oxide and aluminium sulphate 5-30 wt.% (in terms of aluminum oxide).

3. The method of preparation aljumotsinkovanija catalyst for the purification of phenol from impurities aliphatic and aromatic carbonyl compounds by precipitation of zirconium hydroxide, the mixture of hydroxides of aluminum and zirconium, sulfation hydroxides, peptization of the electrolyte solution, screw extrusion catalyst mass and heat treatment, characterized in that as the source of aluminum compounds used aluminum hydroxide, consisting of a mixture of boehmite and pseudoboehmite, taken in a mass ratio of from 1:3 to 3:1 in terms of aluminum oxide.

4. The method according to p. 3, characterized in that as patinator use an aqueous solution of sulfuric acid.

5. The method according to PP.3 and 4, characterized in that the sulfuric acid solution is introduced into the catalyst mass in two steps: in the precipitate of zirconium hydroxide at the stage of sulfation and on stage peptization in the mixture of powders selfaddressed zirconium hydroxide and a hydroxide of al