KR102024896B1 - Process for the preparation of bisphenol A - Google Patents
Process for the preparation of bisphenol A Download PDFInfo
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- KR102024896B1 KR102024896B1 KR1020160035096A KR20160035096A KR102024896B1 KR 102024896 B1 KR102024896 B1 KR 102024896B1 KR 1020160035096 A KR1020160035096 A KR 1020160035096A KR 20160035096 A KR20160035096 A KR 20160035096A KR 102024896 B1 KR102024896 B1 KR 102024896B1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
- C07C37/84—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by crystallisation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/685—Processes comprising at least two steps in series
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C39/00—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring
- C07C39/12—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring polycyclic with no unsaturation outside the aromatic rings
- C07C39/15—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring polycyclic with no unsaturation outside the aromatic rings with all hydroxy groups on non-condensed rings, e.g. phenylphenol
- C07C39/16—Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes
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- Crystallography & Structural Chemistry (AREA)
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Abstract
The present invention relates to a method for producing bisphenol A, and more particularly, by applying ultrasonic waves during the melting process performed to melt the solid chunks generated in the crystallization process during the production of bisphenol A, to shorten the melting time, By extending the melting cycle to increase the operating time of the crystallization process, there is an effect of improving the process efficiency for the production of bisphenol A.
Description
In the present invention, by applying ultrasonic wave during the melting process performed to remove the solid chunks generated in the crystallization process in the preparation of bisphenol A, the time required for the melting process is shortened, the melting process execution period is extended, and thus the crystallization process It relates to a method for producing bisphenol A to increase the operating time of the process efficiency.
Bisphenol A is prepared by reacting an excess of phenol with acetone in the presence of an acid catalyst. In order to obtain high-purity bisphenol A from this reaction product, low boiling point substances including water are removed, and crystallization is performed to precipitate the adduct crystals of bisphenol A and / or bisphenol A and phenol, and the adduct crystal product Bisphenol A is obtained by solid-liquid separation of the containing slurry followed by removal of phenol from the recovered solid adduct.
When the bisphenol A is industrially produced and utilized, a continuous crystallization method is used for efficient purification while obtaining a large capacity. In the continuous crystallization method, a suspension containing the adduct crystals of phenol-bisphenol A obtained in the crystallizer is subjected to solid-liquid separation to recover the solid adduct crystal product, and the liquid phase remains in the remaining material. The liquid portion contains about 70% by weight of phenol, about 15% by weight of bisphenol A, and the remaining other by-products, and for recycling the phenol contained in the liquid part, a reaction mother liquid having undergone a process of removing some by-products. Is circulated and supplied to the reactor which requires excess phenol. In addition, the adduct crystal product is recovered and melted again for transfer to the next process or storage tank.
In particular, the process of forming the adduct crystal product may specifically use a method of an evaporative crystallization process, in which a volatile liquid aliphatic hydrocarbon such as pentane or hexane is used as cooling water, as described in US Pat. No. 4,927,978. .
As described above, the evaporation crystallization process through cooling has an advantage of effectively forming an adduct crystal product, but as the process proceeds, phenol remaining as a by-product forms a solid chunk inside the crystallizer.
Since the generation of chunks reduces not only the efficiency of the overall process but also the recycling and use efficiency of raw materials, the efficient removal of these chunks is an important process in the preparation of bisphenol A.
As a method for washing the chunk inside the crystallizer without breakage, conventionally, a method of performing a thawing process in which the crystallizer is stopped and cleaned through heating of the vessel is used.
However, the melting method of the chunk through the natural melting method usually takes 2 to 3 days, considering that it may be different depending on the scale of the process or the amount of the chunks formed, and particularly, a sufficient temperature among them. The heating up of the furnace and the holding time of the melting reaction took about 40 hours or more, which resulted in an increase in idle time and thus a huge loss of production opportunity.
Therefore, there is a need for an improved proposal for reducing the time required for the melting process and improving the efficiency of the overall process.
In order to solve the above-mentioned conventional problems, the inventors of the present invention, after conducting multifaceted studies, apply ultrasonic waves simultaneously with heating to remove chunks generated during the crystallization process of phenol-bisphenol A adducts. It can be melted more quickly and efficiently, there is no need to excessively increase the heating temperature and time to complete the present invention by confirming that it is also efficient in energy saving.
Accordingly, an object of the present invention is to shorten the melting time for removing the chunks generated in the crystallization process of bisphenol A, and to reduce the energy required, and to extend the melting cycle for removing the chunks. By increasing the operating time of the bisphenol A to improve the overall efficiency of the process.
In order to achieve the above object, the present invention
Introducing bisphenol A and phenol into the crystallization unit;
Performing a crystallization process to produce a phenol-bisphenol A adduct;
Recovering the crystallized phenol-bisphenol A adduct and performing a purification process; And
In the manufacturing method of bisphenol A comprising the step of recovering the obtained bisphenol A after the purification step,
It provides a method for producing bisphenol A, characterized in that the ultrasonic application during the crystallization process.
At this time, the ultrasonic application is characterized in that it is introduced during the thawing (thawing) process for removing the chunks generated during the crystallization process.
In addition, the melting step is characterized in that the heating so that the temperature in the crystallizer is 70 ~ 150 ℃.
In the method for preparing bisphenol A of the present invention, ultrasonic waves are applied during the melting process performed to remove the solid chunks generated in the crystallization process, thereby shortening the time required for the melting process for removing the chunks and extending the cycle of performing the melting process. And according to this increase the operating time of the crystallization process has the effect of improving the process efficiency for the production of bisphenol A.
1 is a flowchart illustrating a method for preparing bisphenol A according to the present invention.
Figure 2 is a schematic diagram of an experimental model for confirming the ultrasonic melting effect according to the present invention, a schematic diagram illustrating the operation of the ultrasonic melter after immersing a flask containing a solid phenol in a thermostat.
3 is an experimental result image of Example 1 for confirming the ultrasonic melting effect according to the present invention, after the ultrasonic wave is applied to the solid phenol heated to 43 ℃.
4 is an experimental result image of Example 2 for confirming the ultrasonic melting effect according to the present invention, after the ultrasonic wave is applied to the solid phenol heated to 48 ℃.
5 is an experimental result image of Comparative Example 1 for confirming the phenol fusion effect according to the conventional method, it is a result image after the same time as the embodiment without the ultrasonic wave applied to the solid phenol heated to 43 ℃.
Hereinafter, the content of the present invention will be described in more detail. However, the following contents are described only for the most representative embodiments in order to help the understanding of the present invention, and the scope of the present invention is not limited thereto, and the present invention should be understood to cover all ranges equivalent to the following contents.
According to the method for preparing bisphenol A of the present invention, the time required for the melting process for removing the chunks by applying ultrasonic waves together with heat in a thawing process performed to remove the chunks generated in the crystallization process of the phenol-bisphenol A adduct. This paper proposes a method to improve the productivity of Bispannel A by greatly reducing the number of steps, extending the melting cycle, and increasing the operating time of the crystallization process.
The chunk referred to in the specification of the present invention is produced in the crystallization process of the phenol-bisphenol A adduct and means a solidified material containing phenol, bisphenol A, and some impurities.
1 is a flowchart illustrating a method for preparing bisphenol A according to the present invention.
Referring to Figure 1, bisphenol A according to the present invention comprises the steps of (S1) adding bisphenol A and phenol to the crystallization unit; (S2) performing a crystallization process to produce a phenol-bisphenol A adduct; (S3) recovering the crystallized phenol-bisphenol A adduct and performing a purification process; And (S4) recovering the bisphenol A obtained after the purification process.
Hereinafter, a method for preparing bisphenol A according to the present invention will be described in detail for each step.
(S1) Raw material crystallization step
First, bisphenol A and an excess of phenol are introduced into the crystallizer using a raw material supply nozzle. The weight ratio of bisphenol A to phenol in the raw material may preferably be 1: 1 to 1: 6, and more preferably the raw material may contain about 35% bisphenol A, about 65% phenol, and other impurities. have.
The bisphenol A and phenol are then circulated through the draft tube and the annular space in the crystallizer and mixed through the impeller rotation at the center of the crystallizer, and finally the mixed bisphenol A and phenol are formed in the form of a suspension.
The crystallizer used in the present invention is generally in the form of a cylindrical vessel and creates an annular space in the vessel and is arranged concentrically, a circulator for circulating the liquid in the vessel through the draft tube and the annular space, the circumference of the inner wall of the cylindrical vessel It is equipped with a plurality of cooling water nozzles to be equipped with a return to introduce the evaporative cooling water into the vessel.
(S2) performing the crystallization process
Next, a crystallization process is performed to obtain an adduct of phenol-bisphenol A as a crystal product.
The crystallization process is carried out in an evaporative cooling manner through a cooling nozzle in the crystallizer.
The cooling nozzle may include a volatile cooling water capable of exhibiting a cooling effect through evaporation. Preferably, the cooling nozzle may be composed of any one or more of volatile aliphatic hydrocarbons, volatile aliphatic carbonyl, and water, and more preferably volatile carbonyl. Or hexane.
The cooling water is sprayed radially through the nozzles, and this injected volatile cooling water is uniformly dispersed in the circulating flow of the raw material solution. In this case, the injection speed of the volatile cooling water may be injected at a speed of preferably 10 to 20 m / sec, more preferably 12 to 18 m / sec for cooling efficiency and side reaction prevention. It can adjust suitably as needed.
The injected cooling water evaporates and lowers and cools the temperature of the crystallizer vessel.
At this time, the cooling water is injected to have a temperature of 0 ~ 70 ℃, preferably 5 ~ 65 ℃, it is controlled to have a cooling temperature of 30 ~ 110 ℃, preferably 35 ~ 105 ℃ by spraying in the crystallization vessel.
The cooling water and the cooling temperature affect the crystal formation and side reactions of the phenol-bisphenol A adduct crystals, and the side reaction of phenol-bisphenol A adduct crystal formation when the cooling water is lowered by spraying the cooling water at a temperature lower than the above range. This can happen. On the contrary, when the cooling temperature is increased by spraying the cooling water at a temperature higher than the above range, crystallization may not sufficiently occur or a desired level of adduct crystal may not be formed.
The phenol-bisphenol A adduct formed through this crystallization process has a composition in which bisphenol A and phenol are physically bonded in a molar ratio of 1: 1. Chunks occur with the formation of the adduct, which leads to problems that cling to the inner wall of the crystallizer or float in suspensions of bisphenol A and phenol, resulting in lower process efficiency.
In order to remove the chunk, a thawing process is performed in which the crystallizer is stopped and the inside of the crystallizer is heated to a temperature higher than a predetermined level. In the melting process, when the temperature inside the crystallizer rises above a certain temperature, the chunk is dissolved, and phenol and bisphenol A present in the chunk again participate in the crystallization process.
Normally, the heating method for the melting process takes a long time of about 2 to 3 days, and in particular, due to an increase in idle time because it takes about 40 hours or more during the heating up and subsequent holding time. Causing a decrease in the production of bisphenol A.
However, the melting process according to the present invention is not merely a conventional method of applying a temperature, but also performs a process of applying ultrasonic waves in the melting process as shown in FIG. 1.
Ultrasonic waves may be applied through an ultrasonic melter (also called an ultrasonic grinder), which converts ultrasonic electrical energy into mechanical vibrations and delivers them to a liquid sample. Due to the vibration and amplitude, expansion (negative pressure) and contraction (positive pressure) occur inside the sample, and cavitation occurs in this process. At this time, a shock wave of high temperature and high pressure is generated, which acts as a very high energy source and can be used for particle dispersing, particle size reduction, and homogenizing in a liquid sample.
Ultrasonic application breaks chunk particles into smaller sizes to shorten the time that the chunks melt and shortens the time required for the entire melting process. Unit output increases.
In addition, the period of the melting process for melting the chunk can be extended to drastically reduce the number of times the melting process is required during the same period. That is, in the case of the existing process, if the melting process was carried out three times in six months, the present invention can secure the same effect with only one time, it is possible to increase the operating time of the crystallizer during the same time compared to the existing process bisphenol A It is possible to further increase the unit yield of.
In addition, in the case of the conventional process, a high production cost was consumed in the production of bisphenol A by performing simple heating for several days, but in the present invention, the same effect can be obtained only by applying ultrasonic waves for several minutes, thereby reducing the production cost. It can be secured.
In the present invention, the frequency of the ultrasonic wave applied to the crystallizer including the solid phase chunk is preferably 20 to 60 kHz, more preferably 30 to 50 kHz. Within this range, it is possible to perform a balanced process without excessive energy waste while ensuring excellent melting efficiency. However, if the range does not impair the object of the present invention, the range of the ultrasonic frequency may vary depending on the amount of generated chunks or the scale of the process.
In addition, preferably the operating temperature of the crystallizer when the application of the ultrasonic wave is adjusted to a cooling temperature of 30 ~ 110 ℃, preferably 35 ~ 105 ℃. In order to melt the chunks, the temperature is increased, and is preferably heated to 70 to 150 ° C, more preferably to 75 to 145 ° C. The temperature corresponds to an appropriate temperature at which melting can occur effectively without side reactions when melting chunks. That is, the chunk contains phenol and bisphenol A, and their melting point (mp) is 40.5 ° C and 158 ° C, respectively, and the melting point (mp) of the phenol-bisphenol A adduct is 50 to 200 ° C, specifically 90. Taking into consideration that the temperature is ˜120 ° C., the chunk is heated to a temperature of 70 ° C. to 150 ° C. so that the chunk can be smoothly melted.
In this case, the application time of the ultrasonic wave may vary depending on the size, volume, or weight of the chunk to be melted, and the like, and is not particularly limited in the present invention. For example, it is preferable that it is 5 minutes-10 hours, More preferably, it can be set as 30 minutes-5 hours. This is because the fusion of the chunk can occur sufficiently without side reactions within the above preferred application time range. However, the preferred time range is based on the scale of a conventional manufacturing process of bisphenol A, and similarly to the frequency of ultrasonic waves described above, the application time of specific ultrasonic waves can be adjusted to an appropriate time according to the amount of chunks produced and the scale of the process. .
(S3) performing purification process
Next, bisphenol A is obtained from the crystallized phenol-bisphenol A adduct through a purification process.
This purification process
(S3-1) obtaining a phenol-bisphenol A adduct crystallized from the suspension in which the crystallization process is performed in (S2) through a first separation process;
(S3-2) heating and melting the obtained adduct; And
(S3-3) The obtained solution is separated into bisphenol A and phenol through a second separation process.
First, the phenol-bisphenol A adduct crystallized through the first separation process of the suspension subjected to the crystallization step (S2) is obtained (S3-1).
The phenol-bisphenol A adduct in the crystalline state is then separated from the suspension via a first separation process, ie a solid-liquid separation process. The first separation process is carried out using a filtration medium suitable for solid removal. For example, it can be performed on rotary filters, belt filters, and (vacuum) disk filters, as well as suitable centrifuges such as skimmer centrifuges, screen-conveyor centrifuges, or push-type centrifuges. have. Preferably, a pressure rotary filter, particularly preferably a rotary vacuum filter, is used.
The phenol-bisphenol A adduct (filter cake) and the filter liquid (liquid portion) in a crystalline state are separated through the first separation process. At this time, the adduct performs a process for producing a subsequent bisphenol A, and the filter liquid contains about 70% by weight of phenol therein and recycles it to the inside of the crystallizer, as shown in FIG. 1.
Next, the obtained adduct is melted by heating to 100 to 160 ° C (S3-2).
The phenol-bisphenol A adduct is then washed with 40 to 70 ° C. phenol before heating. After the washing, the phenol is recycled into the crystallizer as shown in FIG.
Next, the obtained solution is separated into phenol and bisphenol A through a second separation process such as fractional distillation, that is, a liquid-liquid separation process (S3-3).
At this time, bisphenol A performs the following process for recovery, and phenol is recycled into the crystallizer as shown in FIG. 1.
(S4) recovery process
Next, the bisphenol A separated through the liquid-liquid separation process in (S3) is recovered.
The specific apparatus and process required for recovery are not particularly limited in the present invention, and apparatuses and methods known in the art may be employed.
As described above, the present invention manufactures bisphenol A through a crystallization process, in which the application of ultrasonic waves in the crystallization process reduces the melting time required for melting the chunks as the melting process is performed, while extending the execution cycle of the melting process. By doing so, it is possible to secure an effect of improving efficiency while reducing overall process costs.
Thus prepared bisphenol A can be used as raw materials, intermediates and the like in various fields of chemistry, medicine, biotechnology, engineering and the like, and various polymer materials such as polyacrylates, polyetherimides, modified phenolformaldehyde resins and It can be used as a starting material for the preparation of epoxy resins. For example, polycarbonate may be formed by reacting with phosgene by an interfacial process or by reacting with a diaryl carbonate, preferably diphenyl carbonate, by a melting process.
In order to facilitate understanding of the effects of the present invention described above, Examples and Comparative Examples are described below. However, the following descriptions are merely examples of the contents and effects of the present invention, and the scope and effects of the present invention are not limited thereto.
In the following Examples and Comparative Examples it was confirmed whether the effect of the ultrasonic application during the melting process for melting the chunk. The chunks were carried out with phenol for the convenience of experiments, and the temperature at the time of ultrasonication was controlled by the melting point of phenol according to the use of phenol chunks.
Example 1
About 47.05 g (0.5 mole) of molten phenol (m.p 40.5 ° C.) was added to the flask, followed by standing at about 20 ° C. for at least 24 hours to prepare a solid experimental phenol.
After that, as shown in Figure 2, when the water temperature of the ultrasonic melter (Sonicator) was stabilized at 43 ℃, the prepared phenol was installed so as not to touch the bottom of the ultrasonic melter and the ultrasonic melter was operated (using a 40 kHz transducer) ).
As a result of checking the flask after 5 minutes and 10 minutes, it was confirmed that the solid phenol gradually dissolved over time as shown in FIG. 3.
Example 2
About 47.05 g (0.5 mole) of molten phenol (m.p 40.5 ° C.) was added to the flask, followed by standing at about 20 ° C. for at least 24 hours to prepare a solid experimental phenol.
Then, when the temperature of the water introduced into the ultrasonic melter was stabilized at 48 ° C, the prepared phenol was installed so as not to touch the bottom of the ultrasonic melter, and the ultrasonic melter was operated (using a 40 kHz transducer). As a result of checking the flask after 5 minutes, it was confirmed that the solid phenol gradually melted and completely melted after 10 minutes, as shown in FIG. 4.
Comparative Example 1
About 47.05 g (0.5 mole) of molten phenol (m.p 40.5 ° C.) was added to the flask, followed by standing at about 20 ° C. for at least 24 hours to prepare a solid experimental phenol.
Then, when the temperature of the water introduced into the ultrasonic melter was stabilized at 43 ℃, the prepared phenol was installed so as not to touch the bottom of the ultrasonic melter and observed the phenomenon appearing in the flask without operating the ultrasonic melter.
As a result of checking the flask after 5 minutes and 10 minutes, it was confirmed that the solid phenol did not melt as shown in FIG. 5.
Therefore, it can be seen that solid phase phenol (ie, chunk) can be melted quickly and effectively by applying ultrasonic waves according to the present invention based on the experimental results of the Examples and Comparative Examples.
In addition, it can be seen from the results of Examples 1 and 2 that even when ultrasonic waves are applied in the same way, there is a difference in melting efficiency when the temperature at the time of application is different.
From these results, it can be expected that the application of ultrasonic waves in the melting process has the same effect when applied to the chunks presented in the present invention (ie, consisting of phenol, bisphenol A and some impurities). However, temperature control is essential because of the difference in the chunk composition presented.
The production method of bisphenol A of the present invention can improve the production efficiency in various industrial fields that can utilize the bisphenol A process field and purified bisphenol A.
Claims (10)
Performing a crystallization process in an evaporative crystallization method through cooling to produce a phenol-bisphenol A adduct;
Recovering the crystallized phenol-bisphenol A adduct and performing a purification process; And
In the manufacturing method of bisphenol A comprising the step of recovering the obtained bisphenol A after the purification step,
In the crystallization process, the operation of the crystallizer is stopped, and a thawing process is performed to remove chunks, which are solidified materials including phenol, bisphenol A, and impurities,
The melting process is performed by applying ultrasonic waves at a frequency of 20 to 60 kHz while heating the crystallization temperature to 70 to 150 ℃.
The bisphenol A and phenol is a method for producing bisphenol A, characterized in that it is added to the crystallizer in a weight ratio of 1: 1 to 1: 6.
The crystallization process is a method for producing bisphenol A, characterized in that carried out by spraying a cooling water of 0 ~ 70 ℃ to the crystallizer.
The crystallization process is a method for producing bisphenol A, characterized in that the cooling is carried out so that the temperature inside the crystallizer is 30 ~ 110 ℃.
The phenol-bisphenol A adduct is a method for producing bisphenol A, characterized in that physically bonded bisphenol A and phenol in a molar ratio of 1: 1.
The purification process
Obtaining a crystallized phenol-bisphenol A adduct from the suspension obtained through the crystallization process;
Heating and melting the obtained adduct; And
A method for producing bisphenol A, comprising separating the obtained solution into bisphenol A and phenol.
The phenol obtained in the said purification process is recycled to a crystallization method, The manufacturing method of bisphenol A characterized by the above-mentioned.
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