RU2068404C1 - Process for preparing simultaneously phenol, acetone and alfa-methylstyrene - Google Patents

Abstract

FIELD: simultaneous preparation of phenol and acetone by decomposition of cumene hydroperoxide. SUBSTANCE: preparation of phenol, scetone and alpha-methylstyrene is carried by acid decomposition of isopropyl benzene peroxide in two steps: at 60-70 C at first step and 80-100 C at second step in reaction mixture, and isopropyl benzene is added thereto in amount of 18-25 wt%. Decomposed reaction mixture is subjected to washing from catalyst with water in amount of 13-20 % vol%. EFFECT: more efficient preparation process. 5 tbl

Description

 The invention relates to the technology of basic organic synthesis, specifically to the production of phenol, acetone through cumene.

 Phenol is used in the production of caprolactam, diphenylolpropane phenol-formaldehyde resins, in medicine.

 Acetone is widely used as a solvent in the production of diphenylol propane, as well as for the synthesis of many organic substances.

 α-methylstyrene is a monomer in the production of synthetic rubbers and plastics.

 An industrial method for the joint production of phenol and acetone is to obtain isopropylbenzene hydroxide (GPIPB), followed by its decomposition in the presence of sulfuric acid into phenol and acetone. a-methylstyrene in this process is a product of adverse reactions, it is purified and isolated salable according to GOST-19916-74.

Known methods of decomposition GPIPB
in the presence of sulfuric acid and water in an amount of 0.4 to 4.5% at a temperature of 50 to 120 ^o C (1);
decomposition in the presence of sulfuric acid and water additives in a mass ratio of isopropylbenzene hydroperoxide and water 1 (0.008 0.023) (2);
There is a known method for the joint production of phenol, acetone and a-methylstyrene by acid decomposition of isopropylbenzene hydroperoxide in two steps, in the 1st step at a temperature of 40-70 ^° C in the presence of ammonia or water additives at a ratio of ammonia acid (7.6 - 11.5) 1 or water acid (16.7 50) 1, followed by exposure of the reaction mixture to the second stage of the displacement reactor at a temperature of 80 - 100 ^o C and a pressure of 0.3 to 0.5 MPa.

 Acetone is additionally introduced into the displacement reactor in an amount of 10-40 wt. on the reaction mass of decomposition. The exposure of the reaction mass in the displacement reactor is usually carried out for 5 to 25 minutes

 The disadvantages of existing, known methods of decomposition of GPIPB are the relatively low yield of the target products of phenol and a-methylstyrene from the theoretically possible, the high content of salts, sulfates, in the phenolic resin due to the low efficiency of extraction of the catalyst, sulfuric acid, from the reaction mass. The high salt content in the process streams in the phenolic resin causes clogging of the equipment, prevents the use of resin as boiler fuel, and complicates the process of destructive processing.

 The catalyst, sulfuric acid, in the reaction mass in the existing processes is neutralized with alkali. Due to the formation of a stable emulsion, sedimentation of the reaction mixture from sodium sulfates is ineffective. For this reason, frequent boiling of rectification columns takes place, the salts remaining in the reaction mass are concentrated in phenolic resin.

 The aim of the invention is to increase the yield of phenol and a-methylstyrene, complete extraction of salts from the reaction mass of the catalyst to obtain a desalted phenolic resin.

The goal is achieved by carrying out the acid decomposition of IPB hydroperoxide in two stages at a temperature of 60 70 ^o C in the first stage and 80 - 100 ^o C in the second.

 The decomposition is carried out in a reaction mass medium, to which isopropylbenzene is additionally introduced in an amount of 18 25 wt. The decomposed reaction mass is subjected to washing from the catalyst with water, the amount of water for washing is taken 15 20 vol.

 Dilution of GPIPB with isopropylbenzene makes it possible to increase the selectivity of the decomposition process, to increase the degree of conversion of DMPA to a-methylstyrene, thereby increasing the yield of a-MS, and increasing the yield of phenol.

 The presence of a diluent introduced with isopropylbenzene in the reaction mass within the indicated limits facilitates the complete extraction of the catalyst, sulfuric acid, water and thus the complete desalination of the phenolic resin.

Distinctive features of the method are:
the decomposition of isopropylbenzene hydroperoxide is carried out in a reaction mass medium, to which isopropylbenzene is additionally introduced in an amount of 18 25 wt. the decomposed reaction mass is subjected to washing with water from the catalyst, the amount of water for washing is taken 15 20 vol.

 Example 1. In technical isopropylbenzene hydroperoxide containing 1.8% isopropylbenzene, 6.5% dimethylphenylcarbinol (DMF), 1% acetophenone, 90.7% isopropylbenzene hydroperoxide, 20 wt. isopropylbenzene.

The prepared mixture and an aqueous solution of sulfuric acid in an amount of 0.5% are continuously fed into a reactor with a stirrer and a jacket for a coolant. The decomposition of GPIPB is carried out at a temperature of 65 ^o C. The resulting reaction mass is kept for 6 minutes in a boiling water bath. Then water is added to the mixture in an amount of 15 vol. and washed with shaking from sulfuric acid. After delamination for 4 hours, sulfuric acid is absent in the reaction mass. The composition of the reaction mass decomposition is shown in table. one.

 The yield of phenol from the theory is 99.7%. The yield of a-methylstyrene is 75.9%. There is no sulfate content in the resin.

Example 2 (comparisons). Isopropylbenzene technical hydroperoxide containing 1.9% IPB, 1% acetophenone, 6.2% DMFK, 90.9% GPIPB is continuously fed into the reactor with a stirrer and a jacket for a coolant. Into hydroperoxide, acetone was introduced in an amount of 17.9 wt. by weight of HPA, water in a ratio of water acid 20 1 and an aqueous solution of sulfuric acid in an amount of 0.5%
Decomposition is carried out at a temperature of 65 ^o C in the 1st stage and in a boiling water bath (100 ^o C) in the 2nd stage. Exposure to the 2nd stage is carried out for 7 minutes. Then the reaction mass is neutralized with an aqueous alkali solution and left to delaminate for 4 hours.

 The composition of the resulting reaction mass is shown in table. 2.

 The yield of phenol from the theory of 99.01% The yield of a-methylstyrene 76% The content of sodium sulfate in the reaction mass of 0.04 wt. in phenolic resin 0.5 wt.

 Example 3. In technical isopropylbenzene hydroperoxide containing 1.2% isopropylbenzene, 6.9% dimethylphenylcarbinol, 1% acetophenone, 90.9% GPIPB, 25 wt. isopropylbenzene.

The resulting mixture and a solution of sulfuric acid in an amount of 0.5% are continuously fed into the stirred reactor. Decomposition is carried out at a temperature of 60 ^° C. The resulting reaction mass is kept in a boiling water bath for 7 minutes. Then water is added to the mixture in a volume of 20% and washed with shaking from sulfuric acid. After 4 hours of settling, sulfuric acid is absent in the reaction mass.

 The composition of the reaction mass decomposition is shown in table. 3.

The yield of phenol from the theory is 99.62%. The yield of a-methylstyrene is 72.2%. The washing of the reaction mixture from the catalyst is complete, and the ions are qualitatively BaCl ₂ $\genfrac{}{}{0ex}{}{\text{-}}{\text{4}}$ after 4 hours there is no sludge.

Example 4. The reactor is continuously fed technical hydroperoxide composition: isopropylbenzene 20 wt. acetophenol 1% dimethylphenylcarbinol 5.2% IPB hydroperoxide 73.8% solution of sulfuric acid in an amount of 0.5 vol. Decomposition is carried out at a temperature of 65 ^o C.

 The resulting reaction mass was incubated for 10 min in a boiling water bath. Then water is added to the mixture in an amount of 18 vol. and washed with shaking from sulfuric acid.

After 4 hours of delamination, sulfuric acid is absent in the reaction mass. Sodium sulfates in phenolic resin 0.005%
The composition of the reaction mass decomposition is shown in table. 4.

The yield of phenol from the theory of 99.56% The yield of α-methylstyrene 90.8%
The results of the experiments decomposition GPIPB in comparison with the prototype are shown in table. 5.

The use of the method of decomposition of isopropylbenzene hydroperoxide in the reaction mass medium, to which isopropylbenzene is additionally introduced in an amount of 18
25 wt. allows you to increase the yield of phenol from theory to 99.7% and a-methylstyrene to 90.8% to obtain phenolic resin without salts, sulfates, which will greatly simplify its applicability as a boiler fuel and in the process of destructive processing.

 The economic effect of introducing a method for producing phenol, acetone and a-methylstyrene is the sum of the additional production of phenol and a-methylstyrene due to an increase in their yield, simplification of the processing of phenolic resin, simplification of the scheme for the isolation of isopropylbenzene hydroperoxide.

Information sources
1. US patent N 4358618, 1982.

 2. A.S. USSR N 1208757, 1985.

Claims (1)

The method of co-production of phenol, acetone and alpha-methylstyrene by decomposition of isopropylbenzene hydroperoxide in two stages at 60 70 ^o C in the first stage and 60 100 ^o C in the second stage in the presence of an acid catalyst with its subsequent removal and distillation of the reaction mixture, characterized in that technical hydroperoxide add isopropylbenzene in an amount of 18 25% of the total mass of the reaction mixture and the decomposition products are washed with water taken in an amount of 15 25% of the volume of the reaction mixture.

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