Ion exchange resin for condensate polishing and preparation method and system thereof
By preparing strong acid cation exchange resin and strong base anion exchange resin with uniform particle size, the problems of small reaction surface area and large fluid resistance in the condensate polishing system were solved, achieving efficient water treatment and stable equipment operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-21
- Publication Date
- 2026-03-13
AI Technical Summary
In existing condensate polishing systems, uneven resin particle size leads to a small reaction surface area and high fluid resistance, and the system is prone to clogging under high flow rate conditions, affecting equipment operating efficiency and safety.
Strongly acidic cation exchange resins and strongly basic anion exchange resins with particle sizes of 500-700 μm and particle size uniformity coefficients of less than 1.1 were used to conduct suspension polymerization by spraying the dispersed phase through a pressure-type fine atomizing nozzle, thus preparing ion exchange resins with good uniformity. Combined with sulfonation and chloromethylation reactions, the reaction specific surface area was increased and the fluid resistance was reduced.
It increases the specific surface area of the reaction, reduces fluid resistance, decreases ion penetration leakage, extends the service life of the resin, and optimizes the operational stability of the equipment, meeting the water quality requirements under high flow rate conditions in nuclear power plants.
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Figure CN121648987A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of water treatment technology, and in particular to an ion exchange resin for condensate polishing, and its preparation method and system. Background Technology
[0002] In related technologies, nuclear power units employ passive advanced pressurized water reactor technology, and the quality of the secondary loop water directly affects the service life of the steam generator and the safe operation of the unit. In existing conventional condensate polishing systems, the resins mostly utilize traditional suspension polymerization processes, resulting in a Gaussian particle size distribution and a uniformity coefficient (UC) typically greater than 1.4. Fine-particle resins (<400μm) cause a sharp increase in bed pressure drop and easily clog filter elements; coarse-particle resins (>800μm) have slow reaction kinetics and are prone to ion "penetration" leakage. Operating under the high-flow-rate conditions unique to these condensate polishing systems presents problems such as small reaction surface area or high fluid resistance. Summary of the Invention
[0003] The purpose of this application is to provide an ion exchange resin for condensate polishing, as well as a preparation method and system, to solve the problems of small reaction surface area and large fluid resistance.
[0004] To solve the above-mentioned technical problems, this application is implemented as follows:
[0005] In a first aspect, embodiments of this application provide an ion exchange resin, comprising: a strongly acidic cation exchange resin and / or a strongly basic anion exchange resin, wherein the particle size of the strongly acidic cation exchange resin and / or the strongly basic anion exchange resin is 500-700 μm and the particle size uniformity coefficient is less than 1.1.
[0006] Secondly, embodiments of this application also provide a method for preparing an ion exchange resin, the method comprising:
[0007] The monomer, porogen, crosslinking agent and initiator are mixed to obtain the dispersed phase;
[0008] The dispersed phase is injected into a continuous aqueous phase containing a dispersant using a pressure-type fine atomizing nozzle. The injection frequency of the pressure-type fine atomizing nozzle and the injection flow rate of the dispersed phase are adjusted to disperse the dispersed phase into monodisperse droplets and carry out suspension polymerization to obtain copolymer white spheres.
[0009] The copolymer white spheres are subjected to sulfonation to obtain the strongly acidic cation exchange resin, and / or the copolymer white spheres are subjected to chloromethylation and amination to obtain the strongly basic anion exchange resin.
[0010] The strong acid cation exchange resin and / or the strong base anion exchange resin have a particle size of 500-700 μm and a particle size uniformity coefficient of less than 1.1.
[0011] Thirdly, embodiments of this application also provide a system in which the ion exchange resin as described in the first aspect is used during operation.
[0012] The ion exchange resins provided in this application include: a strong acid cation exchange resin and / or a strong base anion exchange resin. The particle size of the strong acid cation exchange resin and / or the strong base anion exchange resin is 500-700 μm and the particle size uniformity coefficient is less than 1.1. The strong acid cation exchange resin and / or the strong base anion exchange resin are less likely to cause ion "penetration" leakage, which can increase the reaction specific surface area and reduce fluid resistance. Attached Figure Description
[0013] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a flowchart of a method for preparing an ion exchange resin according to an embodiment of this application. Detailed Implementation
[0015] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those described herein, and the objects distinguished by "first" and "second" are generally of the same class, without limiting the number of objects; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, "A or B" covers three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0016] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.
[0017] To make the technical problems, technical solutions and advantages of this application clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.
[0018] This application provides an ion exchange resin, comprising: a strongly acidic cation exchange resin and / or a strongly basic anion exchange resin, wherein the particle size of the strongly acidic cation exchange resin and / or the strongly basic anion exchange resin is 500-700 μm and the particle size uniformity coefficient is less than 1.1.
[0019] In this embodiment, the ion exchange resin includes at least one of the strong acid cation exchange resin and the strong base anion exchange resin. The particle size of the strong acid cation exchange resin and / or the strong base anion exchange resin is 500-700 μm and the particle size uniformity coefficient is less than 1.1. 95% of the ion exchange resins have a particle size difference of less than 100 μm. The ion exchange resin is not prone to ion "penetration" leakage, which can increase the reaction specific surface area and reduce fluid resistance.
[0020] Optionally, when the ion exchange resin includes the strongly basic anion exchange resin, the kinetic mass transfer coefficient of the strongly basic anion exchange resin is greater than 0.026 cm / s.
[0021] In this embodiment, the kinetic mass transfer coefficient of the strongly basic anion exchange resin is greater than 0.026 cm / s, which improves the mass transfer efficiency.
[0022] Optionally, the ion exchange resin has an average crushing strength greater than or equal to 1000 g / bead and a permeation ball rate greater than 95%.
[0023] In this embodiment, the average crushing strength of the ion exchange resin is greater than or equal to 1000 g / bead and the permeation ball rate is greater than 95%, so as to achieve "zero breakage" during long-term high-flow-rate operation. The strong acid cation exchange resin or the strong base anion exchange resin, which is not easily broken, hardly produces any debris, thereby further deteriorating the pressure difference and having mechanical stability.
[0024] The ion exchange resins provided in this application include: a strong acid cation exchange resin and / or a strong base anion exchange resin. The particle size of the strong acid cation exchange resin and / or the strong base anion exchange resin is 500-700 μm and the particle size uniformity coefficient is less than 1.1. The strong acid cation exchange resin and / or the strong base anion exchange resin are less likely to cause ion "penetration" leakage, which can increase the reaction specific surface area and reduce fluid resistance.
[0025] The ion exchange resins of this application have been described above. The preparation method of the above-described ion exchange resins will be further described below.
[0026] This application also provides a method for preparing ion exchange resin. For example... Figure 1 As shown, Figure 1 This is a flowchart of the ion exchange resin preparation method provided in the embodiments of this application, such as... Figure 1 As shown, it includes the following steps:
[0027] Step 101: Mix the monomer, porogen, crosslinking agent and initiator to obtain the dispersed phase;
[0028] In this step, the monomer, porogen, crosslinking agent and initiator are mixed to obtain a dispersed phase.
[0029] Optionally, the monomers include styrene and divinylbenzene (DVB), wherein the divinylbenzene may account for 80% of the total mass of the monomers, and the mass of the divinylbenzene may be adjusted according to actual conditions. This application does not limit the mass of the divinylbenzene or its proportion in the total mass of the monomers.
[0030] Step 102: Using a pressure-type fine atomizing nozzle, the dispersed phase is injected into a continuous aqueous phase containing a dispersant. The injection frequency of the pressure-type fine atomizing nozzle and the injection flow rate of the dispersed phase are adjusted to disperse the dispersed phase into monodisperse droplets and perform suspension polymerization to obtain copolymer white spheres.
[0031] In some embodiments, the spray frequency of the pressure-type fine atomizing nozzle can be set to 1500Hz. The spray frequency can be adjusted according to actual conditions, and the spray frequency described in this application is not limited.
[0032] In this step, the dispersed phase is injected into a continuous aqueous phase containing a dispersant using a pressure-type fine atomizing nozzle. The injection frequency of the pressure-type fine atomizing nozzle and the injection flow rate of the dispersed phase are adjusted to disperse the dispersed phase into monodisperse droplets. Suspension polymerization can be carried out in the suspension polymerization system when the monodisperse droplets are stable to obtain copolymer white spheres with a particle size within the target range (i.e., 500-700 μm), eliminating the need for mechanical sieving. Exemplarily, in some embodiments, the ambient temperature can be raised to 90°C and polymerization can be carried out for 8 hours. The porogen is then recovered by distillation to obtain copolymer white spheres with a particle size of 650 μm and a particle size uniformity coefficient (UC) of 1.03. This application does not limit the polymerization conditions and environment and can adjust them according to actual conditions.
[0033] Step 103: Sulfonate the copolymer white spheres to obtain the strongly acidic cation exchange resin, and / or chloromethylate and amination the copolymer white spheres to obtain the strongly basic anion exchange resin.
[0034] Exemplarily, in some embodiments, after the copolymer white spheres are dried, dichloroethane is added to swell them, concentrated sulfuric acid is added dropwise, and a sulfonation reaction is carried out at 100°C for 6 hours, followed by washing until neutral, to obtain a strongly acidic cation exchange resin. Alternatively, after the copolymer white spheres are dried, chloromethyl ether is added for chloromethylation, and amination reaction is carried out with trimethylamine to obtain a strongly basic anion exchange resin. In the above steps of functionalizing the ion exchange resin, the environmental conditions and reaction time can be adjusted according to actual conditions, and this application does not limit the environmental conditions and reaction time.
[0035] By employing microparticle controlled polymerization technology, the particle size uniformity coefficient of the obtained strong acid cation exchange resin and strong base anion exchange resin is controlled to be below 1.1, and the central particle size is positioned at 500-700 μm. This minimizes fluid resistance while ensuring the reaction specific surface area.
[0036] Optionally, the method further includes:
[0037] The ion exchange resin is purified to remove unreacted monomers, oligomers, and linear polymeric organic impurities remaining in the ion exchange resin.
[0038] In this embodiment, the ion exchange resin is purified to remove unreacted monomers, oligomers, and linear polymeric organic impurities remaining in the ion exchange resin.
[0039] Optionally, the purification treatment of the ion exchange resin includes:
[0040] The ion exchange resin was subjected to gradient temperature pure water cleaning;
[0041] The cleaned ion exchange resin is subjected to a first treatment, the first treatment comprising at least one of the following:
[0042] High-temperature pure water rinsing, vacuum suction treatment, or solvent extraction treatment.
[0043] For example, in some embodiments, the ion exchange resin can be sequentially passed through ultrapure water countercurrent cleaning columns at 45°C, 70°C, and 90°C, and the resin can remain in each section of the ultrapure water countercurrent cleaning column for 2 hours to perform gradient temperature pure water cleaning. The temperature of the ultrapure water countercurrent cleaning column and the residence time of the ion exchange resin in each section of the ultrapure water countercurrent cleaning column can be adjusted according to actual conditions. This application does not limit the temperature of the ultrapure water countercurrent cleaning column or the residence time of the ion exchange resin in each section of the ultrapure water countercurrent cleaning column.
[0044] Further, the cleaned ion exchange resin undergoes a first treatment, which includes at least one of high-temperature pure water rinsing, vacuum suction treatment, or solvent extraction treatment. The high-temperature steam stripping treatment includes placing the cleaned ion exchange resin in a cleaning tower and introducing hot water (pure water) at 60-70°C for treatment, with a rinsing water volume of 1-5 bv, to deeply remove residual organic matter. It should be noted that the environmental conditions and time of the high-temperature pure water rinsing can be adjusted according to actual conditions, and this application does not limit the environment and time of the high-temperature pure water rinsing.
[0045] A combined process of "gradient temperature pure water cleaning + first treatment" is used to remove trace amounts of organic residues from the pores of the ion exchange resin by utilizing the penetrating power of high-temperature pure water or other treatments. According to relevant testing methods, such as the "Inspection Specification for Substation Automation Systems" (DL / T 1077) or equivalent national standard testing methods, after soaking the ion exchange resin in 60℃ warm water for 24 hours, the total organic carbon (TOC) leaching value is less than 10 ppm.
[0046] Optionally, when the ion exchange resin includes the strongly basic anion exchange resin, the first treatment of the washed ion exchange resin includes:
[0047] The cleaned strong base anion exchange resin was solvent extracted by an ethanol-water solution, and the extracted strong base anion exchange resin was subjected to a first treatment.
[0048] In this embodiment, based on gradient temperature pure water washing, an alcohol-water mixed solvent extraction is added to remove residual amine odors and oligomers using an ethanol aqueous solution before proceeding to the first treatment.
[0049] Optionally, when the ion exchange resin includes the strongly basic anion exchange resin, the kinetic mass transfer coefficient of the strongly basic anion exchange resin is greater than 0.026 cm / s.
[0050] In this embodiment, 95% of the strongly basic anion exchange resin has a particle size difference of less than 100 μm. This uniform particle size almost eliminates the "channeling" effect, improves the mass transfer efficiency, and makes the kinetic mass transfer coefficient (MTC) of the strongly basic anion exchange resin greater than 0.026 cm / s, exhibiting excellent kinetic performance.
[0051] Optionally, the average crushing strength of the strongly acidic cation exchange resin or the strongly basic anion exchange resin is greater than or equal to 1000 g / bead and the permeation balling rate is greater than 95%. In this embodiment, by optimizing the mass ratio of the crosslinking agent and the pore structure, the average crushing strength of the strongly acidic cation exchange resin or the strongly basic anion exchange resin is greater than or equal to 1000 g / bead and the permeation balling rate is greater than 95%, so as to achieve "zero breakage" during long-term high-flow-rate operation. This type of non-breakable strongly acidic cation exchange resin or strongly basic anion exchange resin produces almost no debris, thereby further worsening the pressure differential.
[0052] Obviously, the ion exchange resin preparation method provided in this application has the technical effects brought about by the ion exchange resin described above, and will not be repeated here.
[0053] This application also provides a nuclear power plant condensate polishing system, wherein the system uses the ion exchange resin described in the above embodiments.
[0054] Under high linear velocity conditions, such as when the operating linear velocity is greater than 120 m / h, the effluent quality of the nuclear power plant condensate polishing system using the ion exchange resin is superior to the effluent quality standard requirements of nuclear power plant condensate polishing systems. The effluent quality of the nuclear power plant condensate polishing system meets the indicators that the sodium ion concentration is less than or equal to 0.05 μg / L, the chloride ion concentration is less than or equal to 0.1 μg / L, and the sulfate ion concentration is less than or equal to 0.1 μg / L, which significantly extends the service life of the ion exchange resin and the operating cycle of the nuclear power plant condensate polishing system.
[0055] In this embodiment, the condensate polishing system of the nuclear power plant can be a secondary loop condensate polishing system for third-generation nuclear power technology (such as the State Nuclear Power AP / CAP series nuclear power plants), or it can be a condensate polishing system for other nuclear power plants. This application does not limit this.
[0056] It should be noted that the system in this embodiment corresponds to the ion exchange resin described above. The implementation methods in the above embodiments are all applicable to the embodiments of this system and can achieve the same technical effect. The system provided in this application embodiment can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Therefore, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail here.
[0057] The strongly acidic cation exchange resin and the strongly basic anion exchange resin provided in this application were mixed at a volume ratio of 2:1 and compared with a commercially available brand of resin. The differences in physicochemical properties are shown in the table below:
[0058]
[0059] Under test conditions of a mixed bed column diameter of 100 mm, a bed height of 1200 mm, an operating flow rate of 120 m / h, and an influent salinity of 100 ppb, the effluent quality of the nuclear power plant condensate polishing system under simulated operating conditions is shown in the table below:
[0060]
[0061] The test results above show that the ion exchange resin in the above embodiments fully meets the conditions specified in this application, such as a particle size of 500-700 μm, a particle size uniformity coefficient of less than 1.1, and an average crushing strength greater than or equal to 1000 g / bead. Especially at an ultra-high flow rate of 120 m / h, relying on its uniform particle structure and high strength, it not only produces excellent effluent quality (meeting the requirements of sodium ion concentration less than or equal to 0.05 μg / L, chloride ion concentration less than or equal to 0.1 μg / L, and sulfate ion concentration less than or equal to 0.1 μg / L), but also exhibits significantly reduced pressure drop and extremely low TOC leaching, fully meeting the application requirements of condensate polishing systems in nuclear power plants.
[0062] To verify the advantages of the ion exchange resin selected in this application in terms of differential pressure performance, the following comparative examples were set up using the controlled variable method.
[0063] Comparative Example 1:
[0064] An ion exchange resin with a uniformity coefficient of 1.08 and a narrow particle size distribution was used. The resin bed height was set to 1200 mm, and the system was operated at room temperature and an empty bed flow rate of 0.02 m / s. The bed pressure differential was 2.52 kPa.
[0065] Comparative Example 2:
[0066] An ion exchange resin with a uniformity coefficient of 1.2 was used, and all other experimental conditions were exactly the same as those in Comparative Example 1. The bed pressure difference was 3.17 kPa.
[0067] Comparative Example 3:
[0068] An ion exchange resin with a uniformity coefficient of 1.6 and a relatively wide particle size distribution was used. All other experimental conditions remained the same as in Comparative Example 1. The bed pressure difference was 7.15 kPa.
[0069] In this comparative example, as the resin uniformity coefficient increases, the bed pressure difference gradually increases. Wherein:
[0070] The resin with a uniformity coefficient of 1.08 exhibits the lowest pressure drop and best hydrodynamic properties.
[0071] The resin with a uniformity coefficient of 1.2 has a slightly higher pressure differential;
[0072] Resins with a uniformity coefficient of 1.6 have a wide particle size distribution, and small particles easily clog the pores, resulting in a significant increase in pressure differential and poor operational stability.
[0073] Therefore, it can be seen that the ion exchange resin with a uniformity coefficient of less than 1.1 selected in this application can effectively reduce the bed pressure difference, improve the equipment operating efficiency and the service life of the resin.
[0074] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0075] The embodiments of this application have been described above, but this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
Claims
1. An ion exchange resin, characterized in that, include: The strong acid cation exchange resin and / or the strong base anion exchange resin have a particle size of 500-700 μm and a particle size uniformity coefficient of less than 1.
1.
2. The ion exchange resin according to claim 1, characterized in that, When the ion exchange resin includes the strongly basic anion exchange resin, the kinetic mass transfer coefficient of the strongly basic anion exchange resin is greater than 0.026 cm / s.
3. The ion exchange resin according to claim 1, characterized in that, The ion exchange resin has an average crushing strength greater than or equal to 1000 g / bead and a permeation ball rate greater than 95%.
4. A method for preparing an ion exchange resin, characterized in that, The method includes: The monomer, porogen, crosslinking agent and initiator are mixed to obtain the dispersed phase; The dispersed phase is injected into a continuous aqueous phase containing a dispersant using a pressure-type fine atomizing nozzle. The injection frequency of the pressure-type fine atomizing nozzle and the injection flow rate of the dispersed phase are adjusted to disperse the dispersed phase into monodisperse droplets and carry out suspension polymerization to obtain copolymer white spheres. The copolymer white spheres are subjected to sulfonation to obtain the strongly acidic cation exchange resin, and / or the copolymer white spheres are subjected to chloromethylation and amination to obtain the strongly basic anion exchange resin. The strong acid cation exchange resin and / or the strong base anion exchange resin have a particle size of 500-700 μm and a particle size uniformity coefficient of less than 1.
1.
5. The method according to claim 4, characterized in that, The method further includes: The ion exchange resin is purified to remove unreacted monomers, oligomers, and linear polymeric organic impurities remaining in the ion exchange resin.
6. The method according to claim 5, characterized in that, The purification treatment of the ion exchange resin includes: The ion exchange resin was subjected to gradient temperature pure water cleaning; The cleaned ion exchange resin is subjected to a first treatment, the first treatment comprising at least one of the following: High-temperature pure water rinsing, vacuum suction treatment, or solvent extraction treatment.
7. The method according to claim 6, characterized in that, When the ion exchange resin includes the strongly basic anion exchange resin, the first treatment of the washed ion exchange resin includes: The cleaned strong base anion exchange resin was solvent extracted by an ethanol-water solution, and the extracted strong base anion exchange resin was subjected to a first treatment.
8. The method according to claim 4, characterized in that, When the ion exchange resin includes the strongly basic anion exchange resin, the kinetic mass transfer coefficient of the strongly basic anion exchange resin is greater than 0.026 cm / s.
9. The method according to claim 4, characterized in that, The average crushing strength of the strongly acidic cation exchange resin or the strongly basic anion exchange resin is greater than or equal to 1000 g / bead and the permeation ball rate is greater than 95%.
10. A condensate polishing system for nuclear power plants, characterized in that, The system is operated using the ion exchange resin as described in any one of claims 1-3.