WO2007069561A1

WO2007069561A1 - Process for production of bisphenol-a

Info

Publication number: WO2007069561A1
Application number: PCT/JP2006/324659
Authority: WO
Inventors: Tatsuo Tanaka
Original assignee: Mitsubishi Chemical Corporation
Priority date: 2005-12-12
Filing date: 2006-12-11
Publication date: 2007-06-21
Also published as: CN101326147B; CN101326147A; KR20080074133A; KR101090194B1

Abstract

Disclosed is a process for production of Bisphenol-A comprising a reaction step of supplying a phenol raw material and an acetone raw material into a reactor filled with an ion exchange resin catalyst to yield a reaction solution containing Bisphenol-A. The process includes a manipulation of temporarily suspending the reaction and subsequently resuming the reaction. For the suspension of the reaction, any one of the following manipulations (a) and (b) is included: (a) reducing the supply of the acetone raw material into the reactor and subsequently suspending the supply of both the acetone raw material and the phenol raw material simultaneously; and (b) suspending the supply of the acetone raw material and subsequently suspending the supply of the phenol raw material. In the process, the liquid part in the reactor after suspending the supply of the phenol raw material has a water content of 0.5 to 2% by weight. The process enables to prevent the deterioration of the ion exchange resin catalyst in the reactor when the reaction is suspended by reason of periodic inspection or the like and also prevent the decrease in activity of the ion exchange resin catalyst after resuming the operation, whereby Bisphenol-A can be produced for a long period in a stable manner.

Description

Specification

Method for producing bisphenol A

Technical field

[0001] The present invention relates to a method for producing bisphenol A, and more specifically, in a method for producing bisphenol A by reacting a phenol raw material with an acetone raw material in the presence of an ion-exchange resin catalyst, the reaction is performed by periodic inspection or the like. Is stopped, the ion exchange resin catalyst in the reactor is prevented from degrading, and the decrease in the activity of the ion exchange resin catalyst is suppressed even after the operation is restarted. The present invention relates to a method for producing bisphenol A that can be produced.

Background art

[0002] Bisphenol A is usually produced by reacting phenol and acetone in the presence of an ion exchange resin catalyst. The reaction is carried out continuously. After the reaction for a certain period, the operation is stopped by regular inspections, and the reaction is resumed after the inspection is completed. During the period from shutdown to restart, the reaction liquid present in the reactor is maintained as it is. At this time, the ion exchange resin catalyst is deteriorated, and countermeasures are being studied. For example, when the operation is stopped, the supply of the acetone raw material is stopped first, the supply of the phenol raw material is stopped after the acetone concentration in the reaction solution falls below a predetermined amount, and the ion exchange resin catalyst is added to the phenol. A method of storing in a liquid is known (for example, see Patent Document 1). In addition, a method is known in which a reaction liquid having a water concentration of 0.2% by weight or more is circulated through the reactor while the operation is stopped (for example, see Patent Document 2). Although the above method has a certain effect on the deterioration of the ion-exchange resin catalyst, the ion-exchange resin catalyst still deteriorates, and the ion-exchange resin catalyst is operated for a long time after restarting operation. In some cases, there was a severe decline in activity, and this was not always a suitable method for industrial-scale production facilities.

[0003] Patent Document 1: JP 2002-255879 A

Patent Document 2: Japanese Patent Laid-Open No. 2005-247781

Disclosure of the invention

Problems to be solved by the invention [0004] The present invention has been made in view of the above circumstances, and an object of the present invention is to produce bisphenol A by reacting phenol and acetone in the presence of an ion-exchange resin catalyst. When the reaction is stopped by periodic inspection, etc., the deterioration of the ion exchange resin catalyst in the reactor is prevented, and the decrease in the activity of the ion exchange resin catalyst is suppressed even after the operation is restarted. Thus, it is an object of the present invention to provide a method for producing bisphenol A capable of producing bisphenol A.

Means for solving the problem

[0005] In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, when the operation is stopped, (a) after the supply of the acetone raw material to the reactor is reduced, the acetone raw material and the phenol raw material are reduced. Includes either the operation of simultaneously stopping the supply, or (b) the operation of stopping the supply of the phenol raw material after stopping the supply of the acetone raw material, and is present in the reactor in the shutdown state. By containing a predetermined amount of water in the reaction solution, it is possible to prevent the deterioration of the ion exchange resin catalyst and to suppress the decrease in the activity of the ion exchange resin catalyst even after the restart of operation, and to stably stabilize the bisphenol over a long period of time. It was found that A can be manufactured, and the present invention has been completed.

That is, the gist of the present invention is that bisphenol A includes a reaction step of supplying a phenol raw material and an acetone raw material to a reactor filled with an ion exchange resin catalyst to obtain a reaction liquid containing bisphenol A. Including the operation of restarting the reaction after the reaction has been stopped, and when stopping the reaction, (a) after reducing the supply of the acetone raw material to the reactor, the acetone raw material and the phenol raw material Including the operation of stopping the supply of phenol raw materials at the same time, or (b) the operation of stopping the supply of phenol raw materials after stopping the supply of aceton raw materials, and after the supply of phenol raw materials is stopped. The present invention resides in a method for producing bisphenol A, characterized in that the water concentration in the liquid part in the reactor is 0.5 to 2% by weight.

The invention's effect

[0007] According to the present invention, when a reaction is stopped by periodic inspection or the like, the reaction is stopped by a method for producing bisphenol A by reacting phenol and acetone in the presence of an ion exchange resin catalyst. In addition to preventing deterioration of the ion exchange resin catalyst in the vessel, Bisphenol A can be produced stably over a long period of time by suppressing the decrease in the activity of the exchange resin catalyst.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of embodiments of the present invention, and the present invention is not limited to these contents. The method for producing bisphenol A of the present invention includes at least a reaction step in which a phenol raw material and an acetone raw material are supplied to a reactor filled with an ion exchange resin catalyst to obtain a reaction liquid containing bisphenol A. To do.

[0009] The reaction step in the present invention usually uses a reactor filled with ion-exchange resin as a catalyst. The phenol feed and acetone feed fed to the reactor are reacted stoichiometrically in excess of phenol. The molar ratio of phenol to acetone (phenol Z acetone) is usually 3 to 30, preferably 5 to 20. The liquid space velocity of the raw material mixture supplied to the reactor is usually 0.2 to 50 Zh. The reaction temperature is usually 30 to 120 ° C, preferably 55 to: LO 0 ° C. The reaction pressure is usually normal pressure to 600 kPa (absolute pressure).

[0010] The above phenol raw material is a raw material mainly composed of phenol. The ability to use pure phenol Other compounds may include bisphenol A, its 2,4-heteroisomer, chroman, trisphenol, and cyclic dimers of isopropanol phenol. The mother liquor separated in the recovery process for recovering bisphenol A, the reaction liquid treated in the impurity treatment process, etc. can be used as they are, or a mixture of these can be recycled. For example, the typical composition when using the mother liquor separated in the recovery process for recovering bisphenol A is 12-30% by weight for bisphenol A and its isomers, and 70-88% by weight for phenol. is there.

[0011] The acetone raw material is a raw material mainly composed of acetone. Pure acetone can be used, but it may contain impurities such as water. Acetone separated and collected in the acetone circulation process can be used as it is or by recycling a mixture with pure acetone.

[0012] The ion exchange resin of the catalyst is not particularly limited, and preferably contains a strong acid cation exchange resin such as a sulfonic acid type, more preferably a partially strong acid cation exchange resin. A resin modified with a cocatalyst such as a wamine compound is used. Examples of ioamine compounds include 2- (4 pyridyl) ethanethiol, 2 mercaptoethylamine, 3-mercaptopropylamine, N, N dimethyl-3-mercaptopropylamine, N, N-zine — Common promoters used in the synthesis of bisphenol A, such as butyl-4-mercaptobutyramine and 2,2 dimethylthiazolidine. The amount of cocatalyst, with respect to acid groups of acidic ion exchangers in (a sulfonic acid group in the case of a sulfonic acid type), usually 2 to 30 mole ^_0/0, preferably from 5 to 20 mol%. Also, a method of mixing a cocatalyst such as alkyl mercaptan with a phenol raw material or an acetone raw material and supplying it to the reactor can be used.

In the method for producing bisphenol A of the present invention, there is no particular limitation on each step performed subsequent to the reaction step, and for example, a known method can be employed. For example, each step performed after the reaction step includes a low-boiling component separation step in which the reaction mixture obtained in the reaction step is separated into a component containing bisphenol A and a low-boiling component containing unreacted acetone. A crystallization step of crystallizing bisphenol A from components containing phenol A as crystals of adducts with phenol to obtain a slurry, and separating the slurry obtained in the crystallization step into crystals and a mother liquor. Recovery process for recovering A as an adduct crystal with phenol, melting the adduct crystal obtained in the recovery process, and removing phenol by means such as distillation to remove bisphenol A. In the phenol process, at least a portion of the separated mother liquor is treated with an alkali and then distilled to separate it into a light component and a heavy component. Process, unreacted acetone separated and recovered from the low boiling point components obtained in the low boiling point components separation step, such as acetone circulation step Ru is circulated and the like in the reaction step.

[0014] In the production method of the present invention, after the above steps including the reaction step are continuously operated, the reaction is stopped by periodic inspection or the like. The reaction can be stopped by (a) an operation in which the supply of the acetone raw material and the phenol raw material is simultaneously stopped after the supply of the acetone raw material to the reactor is reduced, or (b) The operation (b) is preferred because the aceton concentration at the outlet of the reactor can be rapidly reduced, although it is carried out by any one of the operations for stopping the supply of the diol raw material. In operation (b) above, Prior to stopping the supply of acetone raw material, an operation to reduce the supply of acetone raw material continuously or in stages may be performed.

[0015] Does the unreacted acetone in the reaction liquid react with phenol until the supply of the acetone raw material is decreased and the supply of the force or acetone raw material is stopped and the supply of the phenol raw material is stopped? Or, it is discharged out of the reactor together with the reaction solution, and the acetone concentration gradually decreases. The timing of stopping the supply of the phenol raw material is not particularly limited, but is after the concentration of acetone at the outlet of the reactor is usually 0.1% by weight or less, preferably 0.05% by weight or less. In addition, it is preferable to use pure phenol as the phenol raw material used after the supply of the acetone raw material is reduced or after the supply of the acetone raw material is stopped.

In the production method of the present invention, the water concentration in the liquid part in the reactor after the supply of the phenol raw material is stopped is 0.5 to 2% by weight, preferably 0.5 to 1% by weight. is important . If the moisture concentration is less than 0.5% by weight, the activity of the ion-exchange resin catalyst is reduced when the operation is continued for a long time with little effect of suppressing the deterioration of the ion-exchange resin catalyst. More than 5% by weight is required. On the other hand, if the water concentration exceeds 2% by weight, the water does not easily escape from the ion exchange resin catalyst layer when the operation is restarted. It is necessary to perform dehydration operation in advance. Therefore, it is necessary to keep the water concentration at 2% by weight or less, since there is no need for dehydration and no significant decrease in activity is observed after restarting operation.

[0017] The reaction solution immediately after the supply of the acetone raw material contains water generated by the reaction, but the amount of water is reduced as only the phenol raw material is supplied after the supply of the acetone raw material is reduced or stopped. Decrease. In order to set the moisture concentration in the reaction product within the above specific range, it is preferable to add water to the phenol raw material or to supply water directly to the reactor so that the water content falls within the above range.

[0018] The water concentration in the liquid part in the reactor can be measured, for example, with a Karl Fischer-type water concentration measuring device, gas chromatography, or the like. The water concentration can be adjusted by adding water or water-containing funnel. By allowing water in the above range to exist in the liquid part of the reactor, ion exchange is performed. It is possible to suppress the action of substances that degrade the conversion resin catalyst.

[0019] The method for restarting the reaction is not particularly limited. A method of restarting by simultaneously supplying both the phenol raw material and the acetone raw material, and supplying the acetone raw material after starting the supply of the phenol raw material first. The method of starting etc. is mentioned. In particular, it is preferable to supply the raw materials in stages while increasing the amount of phenol raw materials, and start supplying the acetone raw materials immediately after the amount of phenol raw materials reaches the predetermined amount.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

[0021] Examples 1-3 and Comparative Examples 1-2:

The fixed bed reactor (radius = 0. 2m bottom), 15 mole ^_0/0 of the sulfonic acid groups of the sulfonic acid type cation-exchange as catalyst榭fat (Mitsubishii匕学Co. "DIAION SK104HJ) is 2- the (4-pyridyl) cation exchange榭脂modified with ethanethiol and 125L filled with. reactor, (including Pisufuwenoru a and its isomers) phenol 86.3 wt ^_0/0, other compounds 13. A phenolic feedstock (feed rate = 95 kgZh) with 7 wt% and 300 wt% water content, and an acetone feedstock (feed rate = 3.5 kg / h) with 99,7 wt% acetone and 0.3 wt% water The reaction was carried out for 180 days at a reaction temperature of 58 ° C. The acetone conversion rate immediately after the start of the reaction was 98.5%, and the acetone conversion rate after 180 days of operation was 91.5%. Therefore, the supply of acetone raw material to the reactor was stopped, and water as well as phenol raw material was supplied to the reactor as shown in Table 1. Three hours after the supply of the acetone raw material was stopped, the acetone concentration in the effluent from the reactor was 0.05% by weight in all examples, and the water concentration was the value shown in Table 1. The supply of phenol raw material and water to the reactor was stopped, and the quantitative analysis of water and acetone was performed using a gas chromatograph equipped with a fused silica aviation ram and TCD detector (Shimadzu GC-14B The measurement was performed at 220 ° C and the carrier gas was He).

[0022] The reaction liquid in the reactor was not withdrawn, and the catalyst was left at 75 ° C for 30 days in a state where the catalyst was present in the reaction liquid. After that, the phenolic feedstock with the same composition as before the shutdown (feed amount = 9 5 kg / h) and an acetone raw material (feed amount = 3.5 kgZh) were fed, and the reaction was resumed at a reaction temperature of 58 ° C. The acetone conversion immediately after restarting the reaction was the value shown in Table 1. After the reaction resumed, the acetone conversion gradually decreased, and the acetone conversion was 80% with the numbers shown in Table 1.

[0023] It should be noted that in Comparative Example 2, the force that showed a low acetone conversion rate immediately after resuming the reaction was considered to be because a large amount of water still remained in the reactor. When the acetone conversion rate was measured 48 hours after the reaction was resumed, it was recovered to 90.5%, and the reaction was continued in the same manner as in the other examples. The rate has reached 80%.

[0024] [Table 1]

[0025] Comparative Example 3

The reaction was carried out using the same equipment, raw materials and conditions as in Example 1. The acetone conversion rate after 180 days of operation was 91.5%. Therefore, the supply of phenol raw material and acetone raw material was stopped at the same time without reducing the supply of acetone raw material. The acetone concentration in the effluent from the reactor immediately before the supply was stopped was 0.35% by weight, and the water concentration was 0.9% by weight. The reaction solution in the reactor was not withdrawn, and the catalyst was left in the reaction solution at 75 ° C. for 30 days. Thereafter, phenol raw material (feed amount = 95 kgZh) and acetone raw material (feed amount = 3.5 kgZh) were fed into the reactor, and the reaction was resumed at a reaction temperature of 58 ° C. The acetone conversion immediately after resuming the reaction was 86.5%. After 100 days of operation, the acetone conversion rate was 80%

[0026] As described above, the most practical and preferred embodiment at the present time Although the present invention has been described in connection with the present invention, the present invention is not limited to the embodiments disclosed in the specification of the present application, and the scope of the claims and the overall strength of the specification. However, it should be understood that such changes are also within the technical scope of the present invention.

Claims

The scope of the claims

[1] A method for producing bisphenol A, which includes a reaction step of supplying a phenol raw material and an acetone raw material to a reactor filled with an ion exchange resin catalyst to obtain a reaction liquid containing bisphenol A. Including the operation of stopping and then restarting, when stopping the reaction, (a) the operation of simultaneously stopping the supply of acetone raw material and phenol raw material after decreasing the supply of acetone raw material to the reactor, or ( b) includes any operation of stopping the supply of the phenol raw material after the supply of the acetone raw material is stopped, and the water concentration in the liquid part in the reactor after the supply of the phenol raw material is stopped 0.5 to 2% by weight A method for producing bisphenol A,

[2] The method for producing bisphenol A according to claim 1, wherein the supply of the phenol raw material is stopped after the concentration of acetone at the outlet of the reactor becomes 0.1% by weight or less.