JP3425772B2 - Cleaning method of ion exchange resin - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning an ion exchange resin. More specifically, the present invention is a method for washing an ion-exchange resin that efficiently removes the organic compound from an ion-exchange resin to which the organic compound used in various organic synthesis reactions adheres and facilitates subsequent handling such as disposal. It is about the method. [0002] In recent years, the use of ion exchange resins as catalysts in organic synthesis reactions has been actively studied, and various reactions using the ion exchange resins have been industrially put to practical use. This is because when ordinary chemicals are used as a catalyst, post-treatment such as removal of the catalyst from the reaction mixture is complicated, whereas when an ion exchange resin is used as a catalyst,
This is because it has advantages such as easy post-treatment of the reaction mixture. In particular, a fixed bed continuous reaction system in which a granular ion exchange resin is charged into a reactor and a raw material is continuously supplied to and reacted with the reactor is advantageous in that the post-treatment is extremely simple and easy. As an example using such an ion exchange resin as a catalyst,
There is production of 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A). Bisphenol A is known to be an important compound as a raw material for engineering plastics such as polycarbonate resins and polyarylate resins, and epoxy resins, and the demand for bisphenol A has tended to increase in recent years. The bisphenol A is produced by condensing excess phenol with acetone in the presence of an acidic catalyst and optionally a cocatalyst such as a sulfur compound, and using a cation exchange resin as the acidic catalyst. A method for producing bisphenol A has been put to practical use. In the production of bisphenol A, when the ion exchange resin of the catalyst is discarded due to deterioration or the like, the catalyst is usually washed with phenol or the like to elute most of the reaction products in the catalyst, and then disposed of. Is performed. However, since phenol and a trace amount of phenolic compounds remain in the catalyst to be discarded, the catalyst emits a phenolic odor, and phenol is a compound that is not preferable for safety and health. In fact, it is difficult to handle the catalyst in disposal. Incidentally, the allowable concentration of phenol is 5 ppm. As described above, when an ion exchange resin is used as a catalyst in an organic synthesis reaction, when the catalyst is discarded,
In many cases, the handling of the catalyst is made difficult by the organic compounds which are not preferable in terms of safety and health remaining therein. [0003] Under such circumstances, the present invention is to efficiently remove an organic compound from an ion-exchange resin to which the organic compound used for various organic synthesis reactions adheres. It is another object of the present invention to provide a method for cleaning an ion exchange resin which facilitates subsequent handling such as disposal. Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, brought into contact water and / or steam with an ion exchange resin having an organic compound attached thereto. Has found that the object can be achieved. The present invention has been made based on such findings. That is, the present invention, when removing the organic compound from the ion-exchange resin to which the organic compound is attached,
An object of the present invention is to provide a method for cleaning an ion exchange resin, which comprises contacting the ion exchange resin with water and / or steam. In the method of the present invention, in order to remove the organic compound from the ion-exchange resin to which the organic compound has adhered, water and / or steam is used as a washing medium, and this is brought into contact with the ion-exchange resin and washed. A method is used. The water used for this washing is 40 to 100
The one having a temperature of 100 ° C. is preferable, and the steam having a temperature of 100 ° C. or more is used. The washing operation is usually performed at normal pressure. The amount of the washing medium used is appropriately selected depending on the type of the organic compound attached to the ion exchange resin. For example, when the organic compound is phenol, the amount of the washing medium (in terms of water volume) / the amount of the ion exchange resin (the phenol swelling amount) Volume) ratio is usually 0.05 to 6, preferably
0.2-4. If this ratio is less than 0.05, the removal of phenol is not sufficient, while if it exceeds 6, the effect is hardly changed. [0005] The method of the present invention is preferably applied to remove phenol and phenolic compounds from the cation exchange resin used as a catalyst in the production of bisphenol A. In the production of this bisphenol A, a fixed bed continuous reaction system is usually used in which a raw material mixture containing phenol and acetone is continuously supplied to a reactor filled with a cation exchange resin and reacted. [0006] In addition to phenol and acetone, a co-catalyst may be added to the raw material mixture, if desired, for the purpose of increasing the selectivity and the reaction rate. As this co-catalyst, for example,
Alkyl mercaptans such as methyl mercaptan, ethyl mercaptan, n-octyl mercaptan; thiocarboxylic acids such as thioglycolic acid and β-mercaptopropionic acid; aminoalkanethiols such as 2-aminoethanethiol; mercapto alcohols such as mercaptoethanol; Is mentioned. Also, acetone /
The phenol molar ratio is usually selected in the range of 1/30 to 1/3, preferably 1/15 to 1/5. This molar ratio is 1
If the ratio is less than 30/30, the reaction rate is too slow.
When the ratio exceeds 2, the generation of impurities increases, and the selectivity of bisphenol A decreases. On the other hand, the molar ratio of the cocatalyst / acetone is usually selected in the range of 0.1 / 100 to 20/100, preferably 1/100 to 10/100. When the molar ratio is less than 0.1 / 100, the effect of improving the reaction rate and the selectivity of bisphenol A is not sufficiently exhibited,
If it exceeds 20/100, the effect is not so much improved for the amount. As the cation exchange resin for the catalyst, a sulfonic acid cation exchange resin is preferably used. The sulfonic acid-based cation exchange resin may be a strongly acidic cation exchange resin having a sulfonic acid group, and specific examples thereof include a sulfonated styrene / divinylbenzene copolymer, a sulfonated crosslinked styrene polymer, and phenol formaldehyde- Sulfonic acid resins and benzene formaldehyde-sulfonic acid resins are exemplified. These can be used alone, or
Two or more of them can be used in combination. [0008] The reaction temperature is usually selected in the range of 40 to 150 ° C, preferably 60 to 110 ° C. Reaction temperature 4
If the temperature is lower than 0 ° C., the reaction rate is low, and the viscosity of the reaction solution is extremely high. Also,
If the temperature exceeds 150 ° C., reaction control becomes difficult, the selectivity of bisphenol A decreases, and the cation exchange resin of the catalyst may decompose or deteriorate. The liquid hourly space velocity (LHSV) is usually selected in the range of 0.2 to 30 hr ^-1 , preferably 0.5 to 6 hr ^-1 . In this way, the reaction mixture coming out of the reactor filled with the catalyst is subjected to a post-treatment by a known method, and bisphenol A is taken out. Next, an example of this post-processing will be described. First, concentration is performed prior to crystallization. The concentration conditions are not particularly limited, but are usually at a temperature of 130 to 170.
Concentration is performed under the conditions of 100C and a pressure of 100 to 400 torr. If the temperature is lower than 130 ° C., a high vacuum is required,
On the other hand, when the temperature exceeds 170 ° C., impurities may increase or coloring may occur. Further, the concentration of bisphenol A in the concentrated residue is advantageously in the range of 25 to 40% by weight. If this concentration is less than 25% by weight, the recovery of bisphenol A is low, and if it exceeds 40% by weight, it becomes difficult to transfer the slurry after crystallization. Crystallization of an adduct of bisphenol A and phenol from the concentrated residue is usually performed by a cooling crystallization method. The crystallization temperature at this time is 40-70.
C is preferred. If the crystallization temperature is lower than 40 ° C., the viscosity of the crystallization liquid may increase or solidify. If the crystallization temperature exceeds 70 ° C., the dissolution loss of bisphenol A increases,
Not preferred. Next, the adduct of bisphenol A and phenol thus crystallized is separated by a known method, and is usually subjected to a washing treatment with phenol. Subsequently, the washed adduct is decomposed into bisphenol A and phenol. In this case, the temperature is usually 130 to 200 ° C, preferably 150 to 180 ° C.
, While the pressure is usually 20-150 torr
r is selected in the range. Bisphenol A obtained by this decomposition treatment is substantially completely removed from the residual phenol therein by a method such as steam stripping, so that high-quality bisphenol A can be obtained. The method of the present invention is preferably applied in such a process for producing bisphenol A when the ion exchange resin as a catalyst is disposed of due to deterioration or the like. In this case, before contacting water and / or steam with the ion-exchange resin, if necessary, washing with phenol is performed to distill most of the reaction product, and then water and / or steam is used. The ion exchange resin may be washed according to the method described above. The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 Phenol and acetone as raw materials, ethyl mercaptan as a cocatalyst, and a cation exchange resin as a catalyst (sulfonated styrene-divinylbenzene copolymer, manufactured by Mitsubishi Kasei Kogyo Co., Ltd., trade name: DIAION SK- 104
H] to produce bisphenol A. Next, a fixed bed (1.08 cmφ × 59.2 cm) filled with 50 ml of the cation exchange resin (phenol swollen state).
At 75 ° C. under normal pressure at 10 ml / hr. After 18 hours (water flow rate / catalyst volume ratio = 3.6), the catalyst was extracted and the phenol concentration in the catalyst gas phase was measured, which was 5 ppm. Before washing with water,
Although there was an intense phenol odor, no odor was observed in the cleaning catalyst. Example 2 Example 1 was carried out in the same manner as in Example 1, except that the temperature for washing with water was changed to 85 ° C. Sixteen hours after the start of water flow (water flow rate / catalyst volume ratio = 3.2), the phenol concentration in the catalyst gas phase became 5 ppm. Example 3 In Example 1, instead of water, steam was introduced into the fixed bed at 110 ° C. under normal pressure at a water conversion rate of 10 ml / hr. 2.2 hours after the start of the introduction of steam (introduced steam amount (in terms of water) / catalyst amount volume ratio = 0.44), the phenol concentration in the catalyst gas phase became 5 ppm. Example 4 In Example 3, the cleaning temperature by steam was set to 140 ° C.
Except having set it as above, it implemented similarly to Example 3. One hour after the introduction of steam (introduced steam amount (in terms of water) / catalyst amount capacity ratio = 0.2), the phenol concentration in the catalyst gas phase became 5 ppm. According to the present invention, the organic compound is efficiently removed from the ion-exchange resin to which the organic compound used in various organic synthesis reactions adheres, and the subsequent process such as disposal of the ion-exchange resin is performed. Handling can be facilitated. The method of the present invention is preferably applied particularly for removing phenol and phenolic compounds from a cation exchange resin used as a catalyst in the production of bisphenol A.

Continuation of front page (56) References JP-A-4-150951 (JP, A) JP-A-3-52649 (JP, A) JP-A-53-53590 (JP, A) JP-A-64-51148 (JP, A) JP-A-62-42748 (JP, A) JP-A-52-156772 (JP, A) JP-A-2-135148 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B01J 21/00-38/74

Claims (1)

(57) [Claim 1] In an ion-exchange resin used as a catalyst for producing 2,2-bis (4-hydroxyphenyl) propane, prior to discarding the ion-exchange resin, an organic compound is used. A method for cleaning an ion-exchange resin, comprising contacting the ion-exchange resin with water and / or steam when removing the organic compound from the attached ion-exchange resin.