WO2004092102A1

WO2004092102A1 - Method of recovering phenol in bisphenol a production

Info

Publication number: WO2004092102A1
Application number: PCT/JP2004/005239
Authority: WO
Inventors: Masahiro Iwahara; Jun Mase
Original assignee: Idemitsu Kosan Co., Ltd.
Priority date: 2003-04-14
Filing date: 2004-04-13
Publication date: 2004-10-28
Also published as: TW200508187A; JP4615831B2; CN1771218B; CN1771218A; TWI324145B; JP2004315387A

Abstract

In a process for bisphenol A production which comprises cleaning with phenol a strongly acid ion-exchange resin partially modified with a sulfur-amine compound, subsequently condensing phenol with acetone in the presence of the cleaned ion-exchange resin as a catalyst, distilling the resultant liquid reaction mixture under vacuum to separate it into a top fraction and a bottom fraction containing bisphenol A, concentrating the bottom fraction and crystallizing the concentrate, and recovering the bisphenol A from the crystallization product, the phenol solution resulting from the cleaning is distilled to recover the phenol. Thus, the phenol can be recovered, without adversely influencing the quality of bisphenol A, from the phenol solution resulting from the cleaning of the strongly acid ion-exchange resin.

Description

Description Method for recovering phenol in the production of bisphenol A

The present invention relates to a method for recovering phenol in the production of bisphenol A [2,2-bis (4-hydroxyphenyl) propane]. More specifically, in the industrial production process of bisphenol A, a strongly acidic ion-exchange resin is used. The present invention relates to a method for recovering phenol that can be reused from a phenol solution after washing without harming the quality of bisphenol A. Also, the present invention relates to a method for recycling phenol that reuses collected phenol. Background art

Bisphenol A is known to be an important compound as a raw material for engineering plastics such as polycarbonate resin and polyarylate resin, or epoxy resin, and the demand for bisphenol A has been increasing in recent years.

In the production of bisphenol A, a strongly acidic ion exchange resin partially modified with an iodiamine-containing compound is used as a catalyst. An example of the production of bisphenol A using such a catalyst is pyridine A method is disclosed in which a phenol and a ketone are condensed in the presence of a sulfonic acid-based cation exchange resin partially modified with alkanediol, and the preferred modification rate is said to be 2 to 20%. (For example, refer to Japanese Patent Application Laid-Open No. 57-35533). Also disclosed is a method for producing bisphenol A with a good selectivity by dividing acetone into at least two reaction zones by using pyridine alkane thiols as a diamine-containing compound. It is also disclosed that the rate is 2 to 40%, preferably 3 to 30% (for example, see Japanese Patent Application Laid-Open No. H11-246658).

When impurities containing zeo or nitrogen flow out of the strongly acidic ion exchange resin partially modified with ioamine-containing compounds, the quality of the product deteriorates. The reaction starts after washing the resin with phenol, but no method has been proposed to recover the phenol used for washing. Disclosure of the invention

The present invention has been made in view of the above circumstances, and recovers a reusable phenol from a phenol solution after washing a strongly acidic ion exchange resin without adversely affecting the quality of bisphenol A. It aims to provide a method and a method for recycling phenol that reuses collected phenol.

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, in the production of bisphenol A, obtained by washing a strongly acidic ion-exchange resin partially modified with an iodamine-containing compound with phenol. It has been found that the above object can be achieved by subjecting the obtained phenol solution to a distillation treatment. The present invention has been completed based on this knowledge.

That is, in the present invention, a strong acid ion-exchange resin partially modified with an iodamine compound is washed with phenol to form a catalyst. By distilling under reduced pressure, a top fraction and a bottom fraction containing bisphenol A are separated, and a liquid obtained by concentrating the bottom fraction is crystallized, and bisphenol A is recovered from the crystallized product. In the production of phenol, there is provided a method for recovering phenol, comprising recovering phenol by distilling the phenol solution after washing. To offer.

Further, the present invention provides a method for recycling phenol, wherein the recovered phenol is used as a raw material for the condensation reaction or as a crystal washing liquid for the crystallization. BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, examples of the iodiamine compound in the strongly acidic ion exchange resin partially modified with the iodiamine compound include mercaptoaminopyridines such as 3-mercaptoaminopyridine; mercaptoalkylamines such as 2-mercaptoethylamine; Examples thereof include thiazolidines such as 2-dimethylthiazolidine, aminothiophenols such as 4-aminothiophenol, and pyridinealkanethiols such as 4-pyridineethanethiol. Of these, 4-pyridineethanethiol, 2,2-dimethylthiazolidine and 2-mercaptoethylamine are preferred.

Examples of the strongly acidic ion exchange resin include sulfonic acid ion exchange resins such as sulfonated styrene dibutylbenzene copolymer, s / rehonidani crosslinked styrene polymer, phenolic aldehyde aldehyde sulfonic acid resin, and benzeneformaldehyde sulfonic acid resin. And the like.

There is no particular limitation on the method of partially modifying a strongly acidic ion-exchange resin using the above-mentioned diamine-containing compound, and a conventionally known method can be used. For example, the denaturation can be carried out by reacting a strongly acidic ion exchange resin with a diamine-containing compound in a suitable solvent, preferably an aqueous solvent such as water, so as to obtain a desired modification rate. The reaction may be carried out at room temperature, or may be carried out by heating if necessary. By this reaction, an ion exchange group (a sulfonic acid group in a sulfonic acid type ion exchange resin) is contained. The amino group in the thioamine compound reacts with the amino group, and the thio group is introduced into a part of the ion exchange group to be modified.

Here, the “denaturation rate” of the strongly acidic ion exchange resin means a molar modification rate of the strongly acidic ion exchange resin by the iodamine compound containing the strongly acidic ion exchange group. In the present invention, the modification rate of the strongly acidic ion exchange resin with the diamine-containing compound is preferably 5 to 50%, more preferably 8 to 35%. If the modification rate is less than 5% or more than 50%, the yield of bisphenol A may decrease.

In the phenol recovery method of the present invention, a strongly acidic ion exchange resin partially modified with a diamine-containing compound (hereinafter sometimes simply referred to as ion exchange resin) is washed with phenol before the start of the reaction. Washing is performed continuously or batchwise, and is preferably performed until the nitrogen concentration in the phenol solution after washing becomes 0.01 to 5 mass ppm. If the nitrogen concentration in the phenol solution after washing is too high, the quality of bisphenol A deteriorates. Also, if a large amount of phenol is used so that the nitrogen concentration is too low, the time required for cleaning is increased, and it is economically disadvantageous.

When performing cleaning in a continuous, LHS V (liquid hourly space velocity) is generally 0. 0 2 ~: LO hr- preferably 0. 0 5~ 5 hr ^_1. When LHS V is less than 0. 0 2 ^hr-1, there is a possibility that the efficiency is time consuming is deteriorated, and when it is more than 1 0 hr one ^1, which may be required a large amount of phenol. The washing temperature is preferably 45 to 110 ° C, more preferably 55 to 85 ° C. If the washing temperature is too high, decomposition of the ion exchange resin proceeds, and if the washing temperature is too low, phenol may be solidified.

In the production of bisphenol A according to the present invention, a strong acid ion exchange resin partially washed with a diamine compound, which has been washed with phenol as described above, is used as a catalyst, and in the presence of this catalyst, A phenol and acetone are subjected to a condensation reaction in a reaction column to obtain a reaction product liquid. The reaction method is Although not particularly limited, a fixed bed continuous reaction or a batch reaction is preferred. LHSV of the fixed bed In continuous reaction feed mixture (liquid hourly space velocity) is generally 0. 2~3 0 h τ ~ preferably from 0. 5~ 2 0 hr ^1. The reaction temperature is 50-100. C, preferably 60 to 90 ° C., and the phenol-acetone ratio is 4 to 30 (molar ratio), preferably 6 to 20 (molar ratio).

By distilling the reaction product liquid obtained by the above condensation reaction under reduced pressure, a top fraction from which unreacted acetone, by-product water and some phenol were removed from the top of the reaction tower was obtained. From the bottom of the column, a bottom fraction containing bisphenol A and phenol is obtained. The conditions for the distillation under reduced pressure of the reaction product solution were as follows: a pressure of 6.7 to 8.0 kPa and a temperature of 70 to L80. C is preferred.

The above bottom fraction containing bisphenol A and phenol is concentrated to form a concentrated solution having a high concentration of bisphenol A, and bisphenol A is crystallized from the concentrated solution. The bottoms fraction can be concentrated by distilling off excess phenol by distillation, and the concentration of bisphenol A should be 20 to 50% by mass. Is preferred. If this concentration is as low as 20% by mass, the recovery of bisphenol A decreases, and if this concentration is higher than 50% by mass, it becomes difficult to transfer the slurry after crystallization. Crystallization can be performed by cooling the above concentrated solution to 40 to 70 ° C. By crystallization, an adduct of bisphenol A and phenol is obtained as crystals, and the adduct is separated from the concentrated liquid by a method such as filtration or centrifugal filtration.

The separated adduct of bisphenol A and phenol is heated and melted at 100 to 200 ° C. and distilled under reduced pressure to remove phenol from the adduct. The distillation is preferably carried out at a pressure of 1.3 to 13.3 1 1? & A temperature of 150 to 190 ° C. The phenol may be removed from the adduct of bisphenol A and phenol by steam stripping. Bisphenol A in a molten state from which phenol has been removed is turned into droplets by a general granulation device, cooled and solidified into a product.

Before the start of the reaction, the phenol solution obtained by washing with a strongly acidic ion-exchanged resin phenol partially denatured with a diamine-containing compound can be distilled under reduced pressure to recover the phenol. The vacuum distillation conditions are preferably a pressure of 5.3 to 66.7 kPa and a temperature of 100 to 170 ° C, a pressure of 7 to 50 kPa and a temperature of 120 to 150. C is more preferred.

In this vacuum distillation, each component may be separated under different conditions by using one distillation column, or each component may be separated by using several distillation columns. In the distillation of the phenol solution, it is preferable to distill together with the overhead fraction obtained by distilling the reaction product under reduced pressure from the viewpoint of effective use of the distillation column. When the distillation of the phenol solution after the washing is performed together with the overhead fraction, the mixing of the phenol solution and the overhead fraction may be performed continuously or discontinuously. The mixing ratio between the phenol solution after the washing and the fraction at the top of the column is not particularly limited. Before distilling the mixture of the phenol solution and the overhead fraction, the mixture may be heated to 40 to 80 ° C, preferably 50 to 70 ° C, to remove acetone. It is preferable from the viewpoint of recovery and effective use of acetone.

The phenol recovered from the phenol solution after washing or from the mixture of the phenol solution and the overhead fraction is preferably purified by distillation to remove water or by distillation. After this operation, it may be further purified by an ion exchange resin. In this case, an acid-type ion-exchange resin can be used as the ion-exchange resin.

The recovered phenol can be used as a raw material for a condensation reaction of phenol with acetone. Further, it can be used as a washing solution for an adduct of phenol A and phenol obtained as crystals during crystallization. Example

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1

A packed bed reactor having an inner diameter of 13 mm and a height of 900 mm was filled with 74 milliliters of a strongly acidic ion-exchange resin denatured with 17% of water-swollen 4-pyridine ethanethiol. This ion exchange resin was washed with 300 milliliters of water while maintaining the temperature at 60 ° C., and then washed with 300 milliliters of phenol, and the washed phenol solution was collected in a flask. This phenol solution contains 11 mass of water. /. It contained 3.5 mass ppm of nitrogen and 0.8 mass ppm of nitrogen. The phenol solution was heated at normal pressure to remove water.

Next, the phenol in the phenol solution was recovered at 170 ° C. under reduced pressure (66 kPa). The recovered phenol contained 1,000 mass ppm of water, but did not contain any zeolite or nitrogen.

From the inlet of the packed bed reactor, the reaction was carried out at 80 ° C under the conditions of a phenol noacetone ratio of 14 (molar ratio) and a liquid hourly space velocity of 6 h- ¹ . The conversion of acetone was 95%.

At 170 ° C and reduced pressure, unreacted acetone, generated water and some phenol were distilled off from the reaction solution, and separated into a top fraction and a bottom fraction. Excess phenol is distilled off by distilling the bottom fraction under reduced pressure at 154 ° C to adjust the concentration of bisphenol A to 40% by mass. The concentrated solution is cooled at 43 ° C and crystallized. An adduct of bisphenol A and phenol was obtained. For the evaluation of hue of bisphenol A, the hue after standing at 260 ° C. for 10 minutes in an air atmosphere was determined. Hue was determined visually using an APHA standard solution. The hue was 10 (APHA).

Example 2 Bisphenol A was produced in the same manner as in Example 1 except that phenol recovered from the phenol solution after washing in Example 1 and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 10 (AP HA).

Example 3

The top distillate obtained in Example 1 and the phenol solution after washing in Example 1 were mixed at a mass ratio of 1: 1 and heated to 110 ° C. under normal pressure to obtain a mixture. Seacetone and water were removed. Next, the phenol was recovered at a reduced pressure of 170 ° C. and purified with a sulfonic acid type cation exchange resin. Bisphenol A was produced in the same manner as in Example 1 except that purified phenol and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 10 (APHA).

Comparative Example 1

Bisphenol A was produced in the same manner as in Example 1 except that phenol obtained by removing only water from the phenol solution after washing in Example 1 and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 25 (APHA).

Comparative Example 2

The reaction product solution in Example 1 and the phenol solution after washing in Example 1 were mixed at a mass ratio of 1: 1, and unreacted acetone, water and some phenol were removed at 170 ° C. under reduced pressure. It was distilled off and separated into a top fraction and a bottom fraction. This bottom fraction was treated in the same manner as in Example 1 to produce bisphenol A. The hue of the obtained bisphenol A was 35 (APHA).

Example 4

A packed-bed reactor with an inner diameter of 13 mm and a height of 900 mm was filled with 74 milliliters of a strongly acidic ion exchange resin denatured by 23% with 2,2-dimethylthiazolidine. While maintaining the ion exchange resin at a temperature of 60 ° C, After washing with milliliters of water, phenol was washed with 300 milliliters, and the washed phenol solution was collected in a flask. This phenol solution contained 11% by mass of water, 3.6% by mass of ppm, and 0.7 mass ppm of nitrogen. The phenol solution was heated at normal pressure to remove water.

Next, the phenol in the phenol solution was recovered at 170 ° C. under reduced pressure (66 kPa). The recovered phenol contained 1,000 mass ppm of water, 0.2 mass ppm of zeolite, and 0.1 mass ppm of nitrogen. The inlet of the packed bed reactor, phenol / acetone ratio of 1 0 (mole ratio) The reaction was carried out at 80 ° C under conditions of liquid hourly space velocity 6 h ^1. The conversion of acetone was 65%. Next, the reaction product solution was treated in the same manner as in Example 1 to produce bisphenol A. The hue of the obtained bisphenol A was 10 (APHA).

Example 5

Bisphenol A was produced in the same manner as in Example 4 except that phenol recovered from the phenol solution after washing in Example 4 and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 10 (AP HA).

Example 6

The overhead fraction obtained in Example 4 and the phenol solution after washing in Example 4 were mixed at a mass ratio of 1: 1 and heated to 110 ° C. under normal pressure to obtain a mixture. Acetone and water were removed. Next, the phenol was recovered at 170 ° C. under reduced pressure, and purified with a sulfonic acid type cation exchange resin. Bisphenol A was produced in the same manner as in Example 1 except that purified phenol and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 10 (APHA).

Comparative Example 3 Bisphenol A was produced in the same manner as in Example 4 except that phenol obtained by removing only water from the phenol solution after washing in Example 4 and acetone were used as reaction raw materials. The hue of the obtained bisphenol A was 25 (APHA).

Comparative Example 4

The reaction product solution in Example 4 and the phenol solution after washing in Example 4 were mixed at a mass ratio of 1: 1, and unreacted acetone, water and some phenol were distilled off at 170 ° C and reduced pressure. And separated into a top fraction and a bottom fraction. This bottom fraction was treated in the same manner as in Example 4 to produce bisphenol A. The hue of the obtained bisphenol A was 35 (APHA). Industrial applicability

According to the present invention, in the industrial production process of bisphenol A, phenol can be recovered from the phenol solution after washing the strongly acidic ion exchange resin without adversely affecting the quality of bisphenol A.

Claims

The scope of the claims

1. A strongly acidic ion-exchange resin partially modified with a diamine-containing compound is washed with phenol to form a catalyst, and then the phenol and acetone are subjected to a condensation reaction in the presence of the catalyst, and the reaction product is distilled under reduced pressure Thus, the top fraction and the bottom fraction containing bisphenol A are separated, and a liquid obtained by concentrating the bottom fraction is crystallized, and bisphenol A is recovered from the crystallized product to produce bisphenol A. 3. The method for recovering phenol according to claim 1, wherein the phenol solution after the washing is subjected to distillation treatment to recover phenol.

2. The recovery method according to claim 1, wherein the phenol solution after the washing is subjected to a distillation treatment together with a top component obtained by distilling the reaction product under reduced pressure to recover the phenol.

3. The scope of the request to remove acetone and water by heating the phenol solution after washing and the top component obtained by distilling the reaction product under reduced pressure before the distillation treatment is described in item 2 of the request. Collection method.

4. The recovery method according to claim 1, wherein the iodiamine-containing compound is one or more selected from 2,2-dimethylthiazolidine, 2-aminoethanethiol and 4-pyridineethanethiol.

5. A method for recycling phenol, wherein the phenol recovered by the method according to any one of claims 1 to 4 is used as a raw material for the condensation reaction.

6. A method for recycling phenol, wherein the phenol recovered by the method according to any one of claims 1 to 4 is used as a crystal washing solution for the crystallization.