KR101090194B1 - Process for production of bisphenol-A - Google Patents

Abstract

A method for producing bisphenol A comprising a reaction step of obtaining a reaction solution containing bisphenol A by supplying a phenol raw material and acetone raw material to a reactor filled with an ion exchange resin catalyst, the method including the operation of stopping the reaction once and then resuming it. When stopping the reaction, (a) reducing the supply of acetone raw material to the reactor and then simultaneously stopping the supply of the acetone raw material and the phenol raw material, or (b) supplying the phenol raw material after stopping the supply of the acetone raw material. The water concentration of the liquid part in a reactor after stopping supply of a phenol raw material is included in any operation of stopping operation | movement of 0.5 to 2 weight%. By the production method, when the reaction is stopped by periodic inspection or the like, the deterioration of the ion exchange resin catalyst in the reactor is prevented, and the deactivation of the ion exchange resin catalyst is suppressed even after the operation is resumed, and bisphenol A is stably maintained for a long time. It can manufacture.

Ion Exchange Resin Catalyst, Phenolic, Acetone, Bisphenol A, Catalyst Degradation Prevention

Description

Process for production of bisphenol-A

TECHNICAL FIELD The present invention relates to a method for producing bisphenol A. 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 reactor is stopped when the reaction is stopped by periodic inspection or the like. The present invention relates to a method for producing bisphenol A, which prevents deterioration of the ion exchange resin catalyst in the inside and suppresses the deactivation of the ion exchange resin catalyst even after the operation is resumed, thereby stably producing bisphenol A over a long period of time.

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 is carried out for a certain period of time, the operation is stopped by periodic inspection, and the reaction is resumed after the inspection is completed. While resuming from the shutdown, the reaction liquid present in the reactor is maintained as it is, but deterioration of the ion exchange resin catalyst occurs at this time, and a countermeasure thereof has been studied. For example, a method is known in which the supply of acetone raw material is first stopped when the operation is stopped, the supply of the phenol raw material is stopped after the acetone concentration in the reaction solution reaches a predetermined amount or less, and the ion exchange resin catalyst is stored in the phenol liquid (for example, See Patent Document 1). Moreover, the method of carrying out circulation circulation of the reaction liquid whose water concentration is 0.2 weight% or more to a reactor is stopped (for example, refer patent document 2). Although the above method has a certain effect on the deterioration of the ion exchange resin catalyst, the deterioration of the ion exchange resin catalyst may still occur, and the deactivation of the ion exchange resin catalyst in the case of long-term operation after resuming operation may be severe. It was not necessarily a suitable method for industrial scale production equipment.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-255879

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

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

The present invention has been carried out in view of the above circumstances, and an object thereof is to provide ion exchange in a reactor when the reaction is stopped by periodic inspection or the like in a method of producing bisphenol A by reacting phenol and acetone in the presence of an ion exchange resin catalyst. The present invention provides a method for producing bisphenol A, which can prevent deterioration of the resin catalyst and suppress the deterioration of the ion exchange resin catalyst even after the operation is resumed, and can produce bisphenol A stably over a long period of time.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, as a result of earnestly examining, when the operation stops, (a) operation | movement which stops the supply of acetone raw material and a phenol raw material simultaneously after reducing supply of acetone raw material to a reactor, or (b ) Deterioration of the ion exchange resin catalyst by including a predetermined amount of water in the reaction liquid present in the reactor during the shutdown, including any operation of stopping the supply of the phenol raw material after stopping the supply of the acetone raw material. In addition to being able to prevent the reaction, the inventors found that bisphenol A can be stably produced over a long period of time by suppressing the activity deterioration of the ion exchange resin catalyst even after resumption of operation, thereby completing the present invention.

That is, the gist of the present invention is to supply a phenol raw material and acetone raw material to a reactor filled with an ion exchange resin catalyst, and stop the reaction once as a method for producing bisphenol A including a reaction step of obtaining a reaction solution containing bisphenol A. An operation of resuming later, and when the reaction is stopped, (a) reducing the supply of acetone raw material to the reactor and then simultaneously stopping the supply of the acetone raw material and the phenol raw material, or (b) stopping the supply of the acetone raw material. It exists in the manufacturing method of bisphenol A which includes any operation | movement of stopping supply of a phenol raw material after making it, and the water concentration of the liquid part in a reactor after stopping supply of a phenol raw material is 0.5 to 2 weight%. do.

Effects of the Invention

According to the present invention, in the method of producing bisphenol A by reacting phenol and acetone in the presence of an ion exchange resin catalyst, preventing deterioration of the ion exchange resin catalyst in the reactor when the reaction is stopped by periodic inspection or the like. Even after the operation is resumed, the deactivation of the ion exchange resin catalyst can be suppressed, and bisphenol A can be produced stably over a long period of time.

Best Mode for Carrying Out the Invention

Hereinafter, although this invention is demonstrated in detail, description of the element | module described below is a typical example of embodiment of this invention, and this invention is not limited to these content. The manufacturing method of bisphenol A of this invention includes the reaction process of supplying a phenol raw material and acetone raw material to the reactor which filled the ion exchange resin catalyst at least, and obtaining the reaction liquid containing bisphenol A.

In the present invention, the reaction process usually uses a reactor packed with an ion exchange resin as a catalyst. The phenol raw material and the acetone raw material supplied to the reactor are stoichiometrically reacted in excess of phenol. The molar ratio (phenol / acetone) of phenol and 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 / h. The reaction temperature is usually 30 to 120 ° C, preferably 55 to 100 ° C. The reaction pressure is usually atmospheric pressure to 600 kPa (absolute pressure).

The said phenol raw material is a raw material which has phenol as a main component. Pure phenol can be used, but other compounds may include bisphenol A, its 2,4-isomer, chroman, trisphenol, cyclic dimer of isopropenylphenol and the like. The mother liquor separated by the collection | recovery process of collect | recovering bisphenol A, the reaction liquid processed by the impurity treatment process, etc. can be used as it is or these mixed liquids can be recycled. For example, representative compositions in the case of using the mother liquor separated by a recovery process for recovering bisphenol A are 12 to 30% by weight of bisphenol A and isomers thereof and 70 to 88% by weight of phenol.

The acetone raw material is a raw material containing acetone as a main component. Pure acetone may be used, but may contain impurities such as water. The acetone separated and recovered by the acetone circulation process can be used as it is or by recycling the mixed solution of pure acetone.

The ion exchange resin of the catalyst is not particularly limited, and preferably a strong acid cation exchange resin such as a sulfonic acid type, more preferably a resin modified with a cocatalyst such as a sulfur-containing amine compound partially containing a strong acid cation exchange resin is used. do. Examples of the sulfur-containing amine compound include 2- (4-pyridyl) ethanethiol, 2-mercaptoethylamine, 3-mercaptopropylamine, N, N-dimethyl-3-mercaptopropylamine, N, N-di- and general cocatalysts used for the synthesis of bisphenol A, such as n-butyl-4-mercaptobutylamine and 2,2-dimethylthiazolidine. The amount of the supercatalyst used is usually 2 to 30 mol%, preferably 5 to 20 mol% with respect to the acid group (sulfonic acid group in the case of the sulfonic acid type) in the acidic ion exchanger. Moreover, the method of mixing cocatalysts, such as alkyl mercaptan, with a phenol raw material or acetone raw material and supplying them to a reactor can be used.

In the manufacturing method of bisphenol A of this invention, there is no restriction | limiting in particular in each process performed following the said reaction process, For example, a well-known method can be employ | adopted. Examples of the steps carried out following the reaction step include a low boiling point component separation step of separating the reaction mixture obtained in the reaction step into a component containing bisphenol A and a low boiling point component containing unreacted acetone. Crystallization step of crystallizing the adduct with phenol to obtain a slurry; recovery step of separating the slurry obtained in the crystallization step into crystals and mother liquor and recovering bisphenol A as crystals of the adduct with phenol; adduct obtained in the recovery step After melting the crystals and removing phenol by means of distillation or the like, a dephenol process for obtaining bisphenol A and at least a part of the separated mother liquor are subjected to alkali heat treatment, followed by distillation to separate the hard and heavy components, and the heavy components. Impurity treatment process for recombination reaction treatment, low boiling point component The acetone circulation process etc. which isolate | recover and collect | recover unreacted acetone from the low boiling point component obtained at the lith process, and circulate to a reaction process are mentioned.

In the manufacturing method of this invention, the said process including a reaction process is continuously operated, and reaction is stopped by periodic inspection etc. The reaction is stopped by (a) stopping the supply of the acetone raw material and the phenol raw material simultaneously after reducing the supply of the acetone raw material to the reactor, or (b) stopping the supply of the phenol raw material after stopping the supply of the acetone raw material. Although it can carry out by operation of any operation, since operation (b) can reduce acetone concentration in a reactor outlet quickly, it is preferable. In the said operation (b), before stopping supply of acetone raw material, you may perform the operation which reduces supply of acetone raw material continuously or stepwise.

Unreacted acetone in the reaction liquid is either reacted with the phenol or discharged out of the reactor together with the reaction liquid until the supply of the acetone raw material is reduced or until the supply of the acetone raw material is stopped and the supply of the phenol raw material is stopped. The acetone concentration gradually decreases. The timing for stopping the supply of the phenol raw material is not particularly limited, but 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. Moreover, it is preferable to use pure phenol as a phenol raw material used after reducing supply of said acetone raw material or stopping supply of acetone raw material.

In the production method of the present invention, it is important that the water concentration in the liquid portion in the reactor after stopping the supply of the phenol raw material is 0.5 to 2% by weight, preferably 0.5 to 1% by weight. If the moisture concentration is less than 0.5% by weight, the effect of suppressing the action of deterioration of the ion exchange resin catalyst is small, and when it is operated for a long time, the activity concentration of the ion exchange resin catalyst can be seen, so that the moisture concentration is 0.5% by weight or more. On the other hand, if the moisture concentration exceeds 2% by weight, since the water does not easily come out of the ion exchange resin catalyst layer at the time of restarting operation, a decrease in activity immediately after restarting the operation may be seen, and dehydration operation is performed in advance before the reaction is resumed. Needs to be. Therefore, it is necessary to maintain a moisture concentration of 2% by weight or less, which does not require dehydration operation and shows no significant deterioration even after the operation is resumed.

The reaction liquid immediately after stopping the supply of the acetone raw material contains water generated in the reaction, but the water content decreases by supplying only the phenol raw material after reducing or stopping the supply of the acetone raw material. In order to bring the water concentration in the reactant into 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 moisture content is in the above range.

Since the water concentration in the liquid portion in the reactor can be measured, for example, by a Karl Fischer type water concentration meter or gas chromatography, the measurement may be performed using this, or by adding a calculated amount of water or hydrous phenol to the liquid after the measurement. Moisture concentration can be adjusted. The presence of water in the above range in the liquid portion in the reactor can suppress the action of the substance that degrades the ion exchange resin catalyst.

Although it does not specifically limit about the method of resuming a reaction, The method of restarting by supplying both a phenol raw material and acetone raw material simultaneously, the method of starting supply of a phenol raw material first, and then starting supply of acetone raw material etc. are mentioned. have. Especially, the method of supplying gradually increasing a phenol raw material to predetermined amount, and starting supply of acetone raw material immediately after the supply amount of a phenol raw material reaches a predetermined amount is preferable.

Hereinafter, although this invention is demonstrated also in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

Examples 1-3 and Comparative Examples 1-2:

15 mol% of sulfonic acid groups of sulfonic acid type cation exchange resin ("Dionion SK104H" manufactured by Mitsubishi Chemical Corporation) as a catalyst in a fixed bed reactor (radius of the bottom surface = 0.2 m) is modified with 2- (4-pyridyl) ethanethiol 125 L of the prepared cation exchange resin was charged. Phenolic feedstock (feed = 95 kg / h) containing 86.3% by weight of phenol, 13.7% by weight of other compounds (including bisphenol A and isomers thereof) and 300 ppm by weight of water, 99.7% by weight of acetone and 0.3 of water Acetone raw material (feed amount = 3.5 kg / h) containing a weight% was supplied, and reaction was performed at the reaction temperature of 58 degreeC for 180 days. The acetone conversion rate immediately after the start of the reaction was 98.5% and the acetone conversion rate after driving for 180 days was 91.5%. Then, the supply of the acetone raw material to the reactor was stopped, and water was supplied to the reactor along with the phenol raw material at the feed amount shown in Table 1. 3 hours after the supply of the acetone raw material was stopped, the acetone concentration of the effluent from the reactor was 0.05% by weight in all cases, and the water concentration was the values shown in Table 1, so the supply of the phenol raw material and water to the reactor was stopped. Quantitative analysis of water and acetone was carried out using a gas chromatography apparatus equipped with a fused silica capillary column and a TCD detector (manufactured by Shimadzu Corporation, GC-14B, measurement at 220 ° C., carrier gas at He). Was carried out.

The catalyst was left at 75 ° C. for 30 days without removing the reaction solution in the reactor. Thereafter, the phenol raw material (feed amount = 95 kg / h) and acetone raw material (feed amount = 3.5 kg / h) having the same composition as before the operation was stopped, and the reaction was resumed at the reaction temperature of 58 ° C. The acetone conversion rate immediately after the reaction was resumed was the value shown in Table 1. After the reaction was resumed, the acetone conversion was gradually lowered and the acetone conversion was 80% in the days shown in Table 1.

In Comparative Example 2, the acetone conversion rate immediately after the resumption of the reaction showed a low value, but this is considered to be because a large amount of water still remains inside the reactor. As a result of measuring the acetone conversion rate 48 hours after the resumption of the reaction, the recovery was continued to 90.5%. As a result, the reaction continued in the same manner as in the other examples. As a result, the acetone conversion rate reached 80% in 135 days from the resumption of the reaction.

Comparative Example 3:

The reaction was carried out in the same apparatus, raw materials, and conditions as in Example 1. The acetone conversion rate after driving for 180 days was 91.5%. In addition, the supply of phenol and acetone was stopped at the same time without reducing the supply of acetone. The acetone concentration in the effluent from the reactor immediately before the supply stop was 0.35% by weight, and the water concentration was 0.9% by weight. The reaction liquid in the reactor was not removed, and the catalyst was left at 75 ° C. for 30 days while the catalyst was present in the reaction liquid. Then, the phenol raw material (feed amount = 95 kg / h) and acetone raw material (feed amount = 3.5 kg / h) were supplied to the reactor, and reaction was resumed at reaction temperature of 58 degreeC. The acetone conversion rate immediately after the reaction was resumed was 86.5%. After driving for 100 days, the acetone conversion rate reached 80%.

While the present invention has been described in connection with the embodiment which is considered to be the most practical and preferred at the present time, the present invention is not limited to the embodiments disclosed in the present specification, and the gist of the invention can be read from the claims and the entire specification. Or it can be appropriately changed in a range not contrary to the idea, it should be understood that the case accompanied by such a change is the technical scope of the present invention.

Claims (2)

A method for producing bisphenol A comprising a reaction step of obtaining a reaction solution containing bisphenol A by supplying a phenol raw material and acetone raw material to a reactor filled with an ion exchange resin catalyst, the method including the operation of stopping the reaction once and then resuming it. When stopping the reaction, (a) reducing the supply of acetone raw material to the reactor and then simultaneously stopping the supply of the acetone raw material and the phenol raw material, or (b) supplying the phenol raw material after stopping the supply of the acetone raw material. Operation of stopping the reaction, and during the stop of the reaction, the catalyst is present in the reaction liquid without removing the reaction liquid, and the water concentration in the liquid portion in the reactor after stopping the supply of the phenol raw material is 0.5 to 2 Method for producing bisphenol A, characterized in that the weight%. The process for producing bisphenol A according to claim 1, wherein the supply of phenol raw material is stopped after the concentration of acetone at the outlet of the reactor becomes 0.1 wt% or less.