Pretreatment method for resin catalyst for bisphenol A synthesis

Abstract

To provide a pretreatment process for a resin catalyst for synthesizing bisphenol A.SOLUTION: The pretreatment process comprises the following steps: first, purging the resin catalyst with gas to empty residual liquid in the resin catalyst; next, allowing the vented resin catalyst to be in contact with a replacement washing solution for static replacement, and emptying the replacement washing solution; then, allowing the obtained resin catalyst to be in contact with the replacement washing solution for static replacement; and finally, allowing a leachate to be in contact with the resin catalyst and emptying the leachate, to obtain a pretreated resin catalyst. This effectively removes water in a resin catalyst for bisphenol A synthesis, the water content in the resin catalyst being less than 1.0 wt.%, reduces the amount of phenol used as the washing solution, reduces material consumption and energy consumption, and also reduces the cost of the pretreatment process.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for pretreating a resin catalyst for bisphenol A synthesis, and more particularly to a method for reducing the water content in a resin catalyst for bisphenol A synthesis. [Background technology]

[0002] Bisphenol A (BPA), whose chemical name is 2,2-bis(4-hydroxyphenyl)propane, is a widely used organic chemical raw material produced by the condensation reaction of phenol and acetone in the presence of a catalyst. It is primarily used in the production of polymeric materials such as polycarbonate and epoxy resin.

[0003] The ion exchange resin method for synthesizing bisphenol A is widely used in industry due to its simple process flow, low corrosion to equipment, and low waste emissions. The catalyst used in this method is an ion exchange resin obtained by sulfonation or thiol modification using styrene or substituted styrene as the monomer, divinylbenzene as the crosslinker, and liquid paraffin as the porogen. It is characterized by high catalytic activity and good selectivity. Ion exchange resin catalysts have a smooth pore structure and appropriate acidity and strength. However, residual synthetic monomers, crosslinkers, and porogens during the resin preparation process can cause side reactions and even block the pores, affecting catalytic performance. Furthermore, residual water in the ion exchange resin can upset the balance of the bisphenol A synthesis reaction, reducing the conversion rate and occupying the active centers of the catalyst, reducing catalytic activity and slowing the reaction rate. Therefore, ion exchange resins must be pretreated before use to remove residues and water from the resin synthesis.

[0004] Patent Document 1 discloses an industrial-scale continuous process for producing bisphenol by reacting a ketone with a phenol, in which the phenol and the ketone are directly contacted with a modified ion exchange resin catalyst to react and obtain bisphenol. Patent Document 2 discloses a method for preparing bisphenol A, in which phenol and acetone are directly contacted with an acidic ion exchange resin catalyst and an alkyl mercaptan cocatalyst during the reaction process to produce bisphenol A. Patent Document 3 discloses a method for preparing bisphenol 2,2-bis(4'-hydroxyphenyl)propane, in which an antioxidant is contacted with the ion exchange resin catalyst to form a treated and promoted catalyst before the reaction of phenol, acetone, and the catalyst, thereby improving the catalyst's stability and catalytic reaction performance. However, these reports on the production of bisphenol A do not address the pretreatment of the resin to reduce the water content, activation methods, and standard requirements, which are important factors affecting the efficient catalysis of bisphenol A synthesis by the resin catalyst and catalyst stability.

[0005] Currently, the industrial pretreatment method for resin catalysts used in bisphenol A synthesis involves using the reactant phenol as a wash solution, which is injected into a fixed-bed reactor filled with a resin catalyst and brought into contact with the resin catalyst to replace or wash away the residue and water in the resin. Although this method can remove the residue and water from the resin, it takes a long time to operate, requires a large amount of phenol wash solution, increases pretreatment costs, and makes it difficult to reduce the water content of the resin to below 1.0% by weight.

[0006] In short, the current reaction process for synthesizing bisphenol A using a resin catalyst does not take into consideration the pretreatment process of the resin catalyst, and in particular, there are no strict limits on the control of the moisture content in the resin catalyst before the reaction, and there is no effective operation scheme for resin pretreatment. Therefore, there is an urgent need to develop a pretreatment method for a resin catalyst for synthesizing bisphenol A that can shorten the pretreatment process time, reduce the amount of washing liquid used during pretreatment, and quickly reduce the moisture content in the resin catalyst to 1.0 wt% or less.

[0007] Therefore, in this invention, in order to address the problems of the pretreatment process of resin catalysts for bisphenol A synthesis, such as the long treatment time, the large amount of phenol used, and the difficulty of controlling the moisture content in the resin catalyst, a new resin catalyst pretreatment method and a suitable, appropriate phenol concentration and amount of phenol used have been developed.The main novelty is that a continuous treatment method of purging, venting, static replacement, and washing is used, and the resin catalyst is statically replaced and washed using phenol aqueous solutions with different concentration gradients, thereby discharging the physically bound water (bound water) inside the resin catalyst particles in the resin catalyst layer and the unbound water that is strongly bound to the resin catalyst and is difficult to desorb. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Chinese Patent No. CN100546963C Publication [Patent Document 2] Chinese Patent No. CN1150150C Publication [Patent Document 3] Chinese Patent No. CN103974925B Publication Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to propose a pretreatment method for a resin catalyst for bisphenol A synthesis, in which the residual liquid in the resin catalyst is emptied, and then the water in the pores of the substance to be replaced is replaced by a static replacement method (the resin catalyst, which is the substance to be replaced after venting the fixed-bed reactor, is stationary relative to the reactor, and phenol, the replacement liquid, comes into contact with the resin catalyst and enters the internal pore structure of the substance to be replaced).

[0010] The resin catalyst after venting is contacted with a replacement wash, the replacement wash is then emptied, and the resin after static replacement is contacted with the replacement wash using the static replacement method. Finally, the resin catalyst is contacted with the eluent using the eluent, and the eluent is emptied, resulting in a resin catalyst with a low water content. This method allows for rapid and effective removal of water from the resin catalyst for bisphenol A synthesis, shortens the resin pretreatment time, and reduces the amount of washing liquid used. [Means for solving the problem]

[0011] In order to achieve the above object, the technical means adopted by the present invention are as follows.

[0012] A method for pretreating a resin catalyst for bisphenol A synthesis, comprising the steps of: (a) purging the resin catalyst with a purge gas to empty the resin catalyst of any residual liquid; (b) a step of contacting the vented resin catalyst with a replacement washing solution using a static replacement method, allowing the resin catalyst to stand and replace, and then emptying the replacement washing solution; (c) again using the static replacement method, contacting the resin catalyst obtained above with a replacement washing liquid and allowing it to stand for replacement; (d) contacting the eluate with the resin catalyst using an elution method and draining the eluate to obtain a pretreated resin catalyst; The replacement washing liquid in the above steps (c) and (b) is an aqueous phenol solution, and the phenol concentration of the aqueous phenol solution in step (c) is higher than the phenol concentration of the aqueous phenol solution in step (b).

[0013] In the above-mentioned method for pretreating a resin catalyst for bisphenol A synthesis, the step (a) specifically includes introducing a purge gas into a fixed-bed reactor from an upper gas inlet, contacting the resin catalyst with the resin catalyst, removing the liquid in the resin catalyst, and obtaining a resin catalyst after being released into the atmosphere; the purge gas is discharged from a gas outlet at the bottom of the fixed-bed reactor; Specifically, in step (b), the outlet of the fixed-bed reactor is closed, the replacement washing liquid is introduced into the fixed-bed reactor through the washing liquid inlet, and brought into contact with the resin catalyst for static replacement. After the static replacement is completed, the washing liquid outlet of the fixed-bed reactor is opened, and a purge gas is introduced to discharge the washing liquid from the outlet at the bottom of the fixed-bed reactor. Specifically, step (c) includes closing the outlet of the fixed-bed reactor, introducing the replacement washing liquid into the fixed-bed reactor through the washing liquid inlet, contacting it with the resin catalyst, and allowing it to stand for replacement; Specifically, in step (d), the eluent is introduced into the fixed-bed reactor through the washing inlet, contacted with the resin catalyst, and eluted. Then, the washing outlet of the fixed-bed reactor is opened, and the eluent is discharged to obtain the pretreated resin catalyst.

[0014] In the above technical means, the resin catalyst is an acidic ion exchange resin, and is either a gel type or a macroporous type, and the crosslinking degree of the resin is 1.0% to 20%, the particle size range is 0.4 nm to 5.0 nm, and the moisture content is 20 wt% to 90 wt%.

[0015] In the above technical means, in step (a), the purge gas is used to purge and empty the residual liquid in the resin catalyst, the purge gas enters from the top of the resin catalyst layer, and the residual liquid and tail gas are discharged from the bottom of the resin catalyst layer, and the purge gas is one or a combination of air, ethane, propane, nitrogen, argon, or helium.

[0016] In the above technical means, the purge gas temperature in the step (a) is 40°C to 80°C, the flow rate of the purge gas per minute is 1 to 5 times the amount of resin catalyst charged, and the purge time is 10 to 120 minutes.

[0017] In the above technical means, the temperature of the resin catalyst layer during the standing replacement in step (b) is 45°C to 95°C, the phenol content of the replacement washing solution is 10 to 95% by weight, the temperature of the replacement washing solution is 45°C to 95°C, the amount of replacement washing solution used is 0.5 to 3 times the amount of the resin catalyst charged, and the standing time is 0.5 to 24 hours.

[0018] In the above technical means, the purge gas in step (b) is one or a combination of air, ethane, propane, nitrogen, argon, and helium, the purge gas temperature is 40°C to 80°C, the flow rate of the purge gas per minute is 1 to 5 times the resin catalyst loading amount, and the purge time is 10 to 120 minutes.

[0019] In the above technical means, the temperature of the resin catalyst layer during the standing replacement in step (c) is 45°C to 95°C, the phenol content of the replacement washing solution is 80 to 99.5% by weight, the temperature of the replacement washing solution is 45°C to 95°C, the amount of replacement washing solution used is 0.5 to 3 times the amount of the resin catalyst charged, and the standing time is 0.5 to 24 hours.

[0020] In the above technical means, the eluent in the step (d) is phenol, and the temperature of the eluent is 45°C to 95°C.

[0021] In the above technical means, the flow rate of the eluent per unit time in the step (d) is 0.05 to 0.2 times the amount of resin catalyst loaded, and the elution time is 0.5 to 72 hours.

[0022] The present invention solves the following problems:

[0023] 1. In order to address the problems of the long processing time, large amount of phenol usage, and difficulty in controlling the moisture content in the resin catalyst during the pretreatment process of the resin catalyst for bisphenol A synthesis, a new resin catalyst pretreatment method and its suitable and appropriate phenol concentration and usage amount were developed. The main novelty is the use of a continuous processing method of purging, venting, static replacement, and washing, in which the resin catalyst is statically replaced and washed using phenol aqueous solutions with different concentration gradients. 2. According to literature reports, there are no reports of a resin catalyst pretreatment process in the resin-catalyzed bisphenol A production method or process. Currently, in the industrial setting, phenol, a raw material in the bisphenol A reaction, is typically contacted with a resin catalyst before the resin-catalyzed bisphenol A synthesis reaction to remove water from the resin catalyst. This invention pretreats and dehydrates the resin catalyst using a continuous process of purging, venting, settling, and washing.

[0024] 3. Principle of the present invention: In a continuous treatment method of purging and venting, standing and replacing, and washing, (1) the purge and vent process is to discharge the water between the resin catalyst particles in the resin catalyst layer; (2) standing and replacing process is to discharge the physically bound water (bound water) inside the resin catalyst particles in the resin catalyst layer, using the difference in concentration gradient of the phenol solution in the replacing process to prevent the shrinkage or collapse of the internal porous structure of the resin due to excessive or rapid dehydration of the resin bed layer; (3) washing process is to discharge the phenol solution in the washing process, using the difference in concentration between the phenol in the washing solution and the phenol in the resin catalyst to remove the unbound water that is strongly bound to the resin (resin is formed by the polymerization and cross-linking of styrene and stilbene, and vinyl and phenyl groups readily interact strongly with water) and is difficult to desorb. In summary, the resin catalyst pretreatment process proposed in this invention uses a continuous process of purging, venting, standing, and washing, and utilizes the concentration gradient difference of the washings to sequentially remove bound and unbound water in the resin catalyst layer. This allows for the rapid reduction of the water content in the resin catalyst with a small amount of phenol used, without changing the pore structure or chemical properties of the resin layer. [Effects of the Invention]

[0025] The advantages and benefits of the present invention are as follows:

[0026] (1) The novel pretreatment method for a resin catalyst for bisphenol A synthesis according to the present invention is a dehydration method for resin catalyst pretreatment, which is characterized by being able to quickly remove water from the resin catalyst for bisphenol A synthesis and shortening the pretreatment time for the resin catalyst.

[0027] (2) The novel pretreatment method for resin catalysts used in bisphenol A synthesis according to the present invention is characterized by the invention of a dehydration method for resin catalyst pretreatment, which reduces the amount of phenol used as a wash, reduces material consumption, energy consumption, and the cost of the pretreatment process.

[0028] (3) The novel pretreatment method for a resin catalyst for bisphenol A synthesis according to the present invention is a dehydration method for resin catalyst pretreatment, which can effectively remove water from the resin catalyst for bisphenol A synthesis, and is characterized by the moisture content of the resin catalyst being less than 1.0% by weight. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic flow chart of the technical means for pre-treating a resin catalyst for synthesizing bisphenol A according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, the present invention will be described in more detail through specific examples with reference to the accompanying drawings. However, the following examples are merely illustrative and do not limit the present invention, and are not intended to limit the scope of protection of the present invention.

[0031] The specific implementation steps of the method of the present invention will be described below using specific examples. [Example]

[0032] Example 1 Step (a): One liter of gel-type ion exchange resin catalyst (4% crosslinking, particle size range 0.6-1.5 nm, moisture content 60% by weight) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 50°C. The temperature of the resin catalyst layer was maintained at 50°C during the pretreatment process. The outlet valve at the bottom of the fixed-bed reactor was opened, and nitrogen gas (nitrogen gas flow rate 2 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0033] Step (b): Next, 1.5 liters of an aqueous phenol solution (phenol content: 10% by weight) was preheated to 50°C and added to the fixed-bed reactor to contact with the resin catalyst. The resin catalyst layer was maintained at 50°C and allowed to stand for 5 hours. The outlet valve below the fixed-bed reactor was opened, nitrogen gas (nitrogen gas flow rate: 2 liters / min) was introduced from the top of the fixed-bed reactor, and the settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve below the fixed-bed reactor was closed.

[0034] Step (c): Then, 1.5 liters of an aqueous phenol solution (phenol content 99.5 wt%) was preheated to 50°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 50°C and allowed to stand for 5 hours.

[0035] Step (d): The outlet valve at the bottom of the fixed-bed reactor was opened, and phenol (phenol temperature: 50°C, phenol addition rate: 0.05 L / h) was introduced from the top of the fixed-bed reactor. The washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor, and the mixture was eluted for 24 hours to obtain a pretreated resin catalyst.

[0036] According to the method of this example, the resin catalyst pretreatment time was 35 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.93 wt%, which met the pretreatment requirement that the moisture content of the resin catalyst be less than 1.0 wt%.

[0037] Example 2 Step (a): One liter of gel-type ion exchange resin catalyst (crosslinking degree 8%, particle size range 0.4-1.5 nm, moisture content 30 wt%) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 70°C. The temperature of the resin catalyst layer was maintained at 70°C during the pretreatment step. The outlet valve at the bottom of the fixed-bed reactor was opened, and air (air flow rate 2.5 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 60 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0038] Step (b): Next, 1.5 liters of an aqueous phenol solution (phenol content 95% by weight) was preheated to 70°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 70°C and allowed to stand for 4 hours. The outlet valve below the fixed-bed reactor was opened, and air (air flow rate 2.5 liters / min) was introduced from the top of the fixed-bed reactor. The settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor and purged for 60 minutes, after which the outlet valve below the fixed-bed reactor was closed.

[0039] Step (c): Then, 1.5 liters of an aqueous phenol solution (phenol content 98.5 wt%) was preheated to 70°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 70°C and allowed to stand for 4 hours.

[0040] Step (d): The outlet valve at the bottom of the fixed-bed reactor was opened, and phenol (phenol temperature: 70°C, phenol addition rate: 0.1 L / h) was introduced from the top of the fixed-bed reactor. The washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor, and the mixture was eluted for 20 hours to obtain a pretreated resin catalyst.

[0041] According to the method of this example, the resin catalyst pretreatment time was 30 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.95 wt%, which met the pretreatment requirement that the moisture content of the resin catalyst be less than 1.0 wt%.

[0042] Example 3 Step (a): One liter of macroporous ion-exchange resin catalyst (crosslinking degree 6%, particle size range 0.8-2.0 nm, moisture content 65% by weight) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 45°C. The temperature of the resin catalyst layer was maintained at 45°C during the pretreatment step. The outlet valve at the bottom of the fixed-bed reactor was opened, and argon gas (argon gas flow rate 2 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0043] Step (b): Next, 2 liters of an aqueous phenol solution (phenol content: 52.5% by weight) was preheated to 45°C and added to the fixed-bed reactor to contact with the resin catalyst. The resin catalyst layer was maintained at 45°C and allowed to stand for 5 hours. The outlet valve at the bottom of the fixed-bed reactor was opened, argon gas (argon gas flow rate: 2 liters / min) was introduced from the top of the fixed-bed reactor, and the settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0044] Step (c): Then, 2 liters of an aqueous phenol solution (phenol content: 80% by weight) was preheated to 45°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 45°C and allowed to stand for 8 hours.

[0045] Step (d): The outlet valve at the bottom of the fixed-bed reactor was opened, and phenol (phenol temperature: 45°C, phenol addition rate: 0.15 L / h) was introduced from the top of the fixed-bed reactor. The washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor, and the mixture was eluted for 20 hours to obtain a pretreated resin catalyst.

[0046] According to the method of this example, the resin catalyst pretreatment time was 33 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.92 wt%, which met the pretreatment requirement of the moisture content of the resin catalyst being less than 1.0 wt%.

[0047] Example 4 Step (a): One liter of macroporous ion-exchange resin catalyst (crosslinking degree 10%, particle size range 0.5-1.2 nm, moisture content 25% by weight) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 90°C. The temperature of the resin catalyst layer was maintained at 90°C during the pretreatment step. The outlet valve at the bottom of the fixed-bed reactor was opened, and nitrogen gas (nitrogen gas flow rate 1.5 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0048] Step (b): Next, 2.5 liters of an aqueous phenol solution (phenol content 75% by weight) was preheated to 90°C and added to the fixed-bed reactor to contact with the resin catalyst. The resin catalyst layer was maintained at 90°C and allowed to stand for 3 hours. The outlet valve below the fixed-bed reactor was opened, nitrogen gas (nitrogen gas flow rate 1.5 liters / min) was introduced from the top of the fixed-bed reactor, and the settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve below the fixed-bed reactor was closed.

[0049] Step (c): Then, 1.5 liters of an aqueous phenol solution (phenol content 90% by weight) was preheated to 90°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 90°C and allowed to stand for 3 hours.

[0050] Step (d): The outlet valve below the fixed-bed reactor was opened, and phenol (phenol temperature 90°C, phenol addition amount 0.125 L / h) was introduced from the top of the fixed-bed reactor, and the washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor. The mixture was eluted for 21 hours to obtain a pretreated resin catalyst.

[0051] According to the method of this example, the resin catalyst pretreatment time was 28 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.90 wt%, which met the pretreatment requirement of the moisture content of the resin catalyst being less than 1.0 wt%.

[0052] Example 5 Step (a): One liter of gel-type ion-exchange resin catalyst (10% crosslinking, particle size range 0.5-1.2 nm, moisture content 27% by weight) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 80°C. The temperature of the resin catalyst layer was maintained at 80°C during the pretreatment step. The outlet valve at the bottom of the fixed-bed reactor was opened, and helium gas (helium gas flow rate 2.5 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 60 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0053] Step (b): Next, 2 liters of an aqueous phenol solution (phenol content: 80% by weight) was preheated to 80°C and added to the fixed-bed reactor to contact with the resin catalyst. The resin catalyst layer was maintained at 80°C and allowed to stand for 4 hours. The outlet valve at the bottom of the fixed-bed reactor was opened, and helium gas (helium gas flow rate: 2.5 liters / min) was introduced from the top of the fixed-bed reactor. The settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor and purged for 60 minutes, after which the outlet valve at the bottom of the fixed-bed reactor was closed.

[0054] Step (c): Then, 2 liters of aqueous phenol solution (phenol content 95 wt%) was preheated to 80°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 80°C and allowed to stand for 4 hours.

[0055] Step (d): The outlet valve at the bottom of the fixed-bed reactor was opened, and phenol (phenol temperature: 80°C, phenol addition rate: 0.2 L / h) was introduced from the top of the fixed-bed reactor. The washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor, and the mixture was eluted for 20 hours to obtain a pretreated resin catalyst.

[0056] According to the method of this example, the resin catalyst pretreatment time was 30 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.98 wt%, which met the pretreatment requirement that the moisture content of the resin catalyst be less than 1.0 wt%.

[0057] Example 6 Step (a): One liter of gel-type ion-exchange resin catalyst (crosslinking degree 6%, particle size range 1.2-2.5 nm, moisture content 40 wt%) was loaded into a fixed-bed reactor, and the resin catalyst layer was preheated to 65°C. The temperature of the resin catalyst layer was maintained at 65°C during the pretreatment step. The outlet valve at the bottom of the fixed-bed reactor was opened, and nitrogen gas (nitrogen gas flow rate 2.5 L / min) was introduced from the top of the fixed-bed reactor. The residual liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0058] Step (b): Next, 2.0 liters of an aqueous phenol solution (phenol content: 70% by weight) was preheated to 65°C and added to the fixed-bed reactor to contact with the resin catalyst. The resin catalyst layer was maintained at 65°C and allowed to stand for 6 hours. The outlet valve at the bottom of the fixed-bed reactor was opened, nitrogen gas (nitrogen gas flow rate: 2.5 liters / min) was introduced from the top of the fixed-bed reactor, and the settled liquid was discharged from the outlet at the bottom of the fixed-bed reactor. After purging for 30 minutes, the outlet valve at the bottom of the fixed-bed reactor was closed.

[0059] Step (c): Then, 1.5 liters of an aqueous phenol solution (phenol content 90% by weight) was preheated to 65°C and added to the fixed-bed reactor to contact with the resin catalyst, and the resin catalyst layer was maintained at 65°C and allowed to stand for 6 hours.

[0060] Step (d): The outlet valve at the bottom of the fixed-bed reactor was opened, and phenol (phenol temperature: 65°C, phenol addition rate: 0.2 L / h) was introduced from the top of the fixed-bed reactor. The washing liquid was discharged from the outlet at the bottom of the fixed-bed reactor, and the mixture was eluted for 20 hours to obtain a pretreated resin catalyst.

[0061] According to the method of this example, the resin catalyst pretreatment time was 33 hours, and the moisture content of the resin catalyst after treatment was reduced to 0.96 wt%, which met the pretreatment requirement that the moisture content of the resin catalyst be less than 1.0 wt%.

[0062] Table 1 summarizes the moisture content of the resin catalyst before treatment, the pretreatment time, and the moisture content of the resin catalyst after pretreatment for the examples of the present invention. Table 1 shows that when the pretreatment method for a resin catalyst of the present invention is used, the pretreatment time is 28 to 35 hours if the requirement of a moisture content of less than 1.0% by weight of the resin catalyst after pretreatment is met. When viewed in conjunction with the above examples of the present invention, it can be seen that the pretreatment method for a resin catalyst of the present invention shortens the pretreatment time, reduces the amount of washing liquid used, and can quickly and efficiently meet the requirement of a moisture content of less than 1.0% by weight in the pretreatment of a resin catalyst.

[0063] [Table 1]

[0064] Both the prior art and the examples of the present invention use phenol as a wash solution. The differences are as follows: (1) in the prior art, the resin catalyst is washed with phenol alone to dehydrate it, a process that takes time and requires a large amount of phenol; (2) in the examples of the present invention, the resin is pretreated and dehydrated using a continuous process of purging, venting, settling, and washing. Specifically, the present invention uses a purge and vent to drain the water between the resin catalyst particles in the resin catalyst layer. In the settling step, an aqueous phenol solution is used as the replacement solution to replace and drain the physically bound water (bound water) inside the resin catalyst particles in the resin catalyst layer. In the washing step, the phenol in the wash solution is strongly bound to the resin and removes the unbound water (unbound water). The two methods also differ in treatment conditions, wash solution concentration, and amount of wash solution used.

[0065] From the perspective of pretreatment effectiveness, the method of the present invention can rapidly remove water from resin catalysts for bisphenol A synthesis, shorten the pretreatment time for the resin catalyst, and effectively remove water from the resin catalyst for bisphenol A synthesis, resulting in a water content of less than 1.0 wt%. This technical solution has good pretreatment effects and is applicable to resin catalysts with different water contents. The water content of the resin catalyst obtained by the method of the present invention is significantly reduced to 1.0 wt%, meeting the catalytic performance and stability requirements for synthesizing bisphenol A from acetone and phenol. However, the high water content of untreated resin catalysts (25-60 wt%) affects catalytic activity. In particular, an increase in water content leads to a decrease in phenol conversion, a decrease in bisphenol A yield, and an increase in by-products, making it impossible to meet industrial production requirements. This demonstrates the technical necessity and advantages of adopting the method of the present invention.

[0066] Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to the above embodiments, and various simple modifications can be made to the technical means of the present disclosure within the scope of the technical idea of ​​the present disclosure, and such simple modifications are equally included in the scope of protection of the present disclosure.

[0067] Furthermore, the specific technical features described in the above specific embodiments can be combined in any suitable manner if there is no contradiction, but to avoid unnecessary repetition, the present disclosure omits various possible combinations.

[0068] It should be noted that the various embodiments of the present disclosure can be combined in any manner, and as long as they do not contradict the spirit of the present disclosure, they should also be considered as the contents disclosed in the present disclosure.

Claims

1. A method for pretreating a resin catalyst for bisphenol A synthesis, comprising: (a) purging a resin catalyst in a reactor using a purge gas and discharging residual liquid in the resin catalyst from the reactor; (b) contacting the vented resin catalyst with a replacement washing solution using a static replacement method, and performing static replacement; and discharging the replacement washing solution from the reactor after the static replacement; (c) again using the static replacement method, contacting the resin catalyst obtained above with a replacement washing liquid and allowing it to stand for replacement; (d) contacting an eluate, which is phenol, with the resin catalyst using an elution method, and discharging the eluate from the reactor after contact to obtain a pre-treated resin catalyst; The replacement washing liquid in the step (c) and the step (b) is an aqueous phenol solution, and the phenol concentration of the aqueous phenol solution in the step (c) is higher than the phenol concentration of the aqueous phenol solution in the step (b).

1. A method for pretreating a resin catalyst for bisphenol A synthesis, comprising:

2. In the step (a), a purge gas is introduced into a fixed-bed reactor from an upper gas inlet, brought into contact with a resin catalyst, and liquid in the resin catalyst is removed to obtain a resin catalyst after being released into the atmosphere; the purge gas is discharged from a gas outlet at the bottom of the fixed-bed reactor; In the step (b), the outlet of the fixed-bed reactor is closed, the replacement washing liquid is introduced into the fixed-bed reactor through the washing liquid inlet, brought into contact with the resin catalyst, and statically replaced; after the static replacement is completed, the washing liquid outlet of the fixed-bed reactor is opened, a purge gas is introduced, and the washing liquid is discharged from the outlet at the bottom of the fixed-bed reactor; In the step (c), the outlet of the reactor is closed, the replacement washing liquid is introduced into the fixed-bed reactor through the washing liquid inlet, and the replacement washing liquid is brought into contact with the resin catalyst and allowed to stand for replacement; In the step (d), an eluent, which is phenol, is introduced into the fixed-bed reactor through a washing inlet, brought into contact with the resin catalyst, eluted, and the washing outlet of the fixed-bed reactor is opened, and the eluent is discharged to obtain a pretreated resin catalyst.

2. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 1.

3. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the resin catalyst is an acidic ion exchange resin, either a gel type or a macroporous type, and the degree of cross-linking of the resin is 1.0% to 20%, the particle size range is 0.4 nm to 5.0 nm, and the moisture content is 20 wt% to 90 wt%.

4. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein in step (a), the residual liquid in the resin catalyst is purged and discharged from the reactor using a purge gas, the purge gas enters from the top of the resin catalyst layer, and the residual liquid and tail gas are discharged from the bottom of the resin catalyst layer, and the purge gas is one or a combination of air, ethane, propane, nitrogen, argon, or helium.

5. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the purge gas temperature in step (a) is 40°C to 80°C, the flow rate of the purge gas per minute is 1 to 5 times the amount of the resin catalyst charged, and the purge time is 10 to 120 minutes.

6. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the temperature of the resin catalyst bed during the static replacement in step (b) is 45°C to 95°C, the phenol content of the replacement washing solution is 10 to 95% by weight, the temperature of the replacement washing solution is 45°C to 95°C, the amount of the replacement washing solution used is 0.5 to 3 times the amount of the resin catalyst charged, and the static replacement time is 0.5 to 24 hours.

7. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the purge gas in step (b) is one or a combination of air, ethane, propane, nitrogen, argon, and helium, the purge gas temperature is 40°C to 80°C, the flow rate of the purge gas per minute is 1 to 5 times the amount of the resin catalyst charged, and the purge time is 10 to 120 minutes.

8. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the temperature of the resin catalyst layer during the standing replacement in step (c) is 45°C to 95°C, the phenol content of the replacement washing solution is 80 to 99.5% by weight, the temperature of the replacement washing solution is 45°C to 95°C, the amount of the replacement washing solution used is 0.5 to 3 times the amount of the resin catalyst charged, and the standing time is 0.5 to 24 hours.

9. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the temperature of the eluent in step (d) is 45 to 95°C.

10. 3. The method for pretreating a resin catalyst for bisphenol A synthesis according to claim 2, wherein the flow rate per hour of the eluent in step (d) is 0.05 to 0.2 times the amount of the resin catalyst loaded, and the elution time is 0.5 to 72 hours.

Images