Method for measuring high temperature resistance of resin

Abstract

The invention discloses a method for measuring the high-temperature resistance of resin, and belongs to the technical field of high-temperature-resistant precision treatment resin testing. According to the method, the process of field resin failure is simulated through high-temperature sodium chloride solution treatment, then the resin is regenerated through acid and alkali, and the process of failure regeneration of the field resin under the high-temperature condition is repeatedly reduced, so that the temperature resistance of the new resin can be rapidly evaluated; and the service life of the resin can be predicted according to the relationship between the regeneration times and the crushing strength reduction rate.

Description

Technical Field

[0001] The invention belongs to the technical field of high temperature resistant fine treatment resin testing, and in particular relates to a method for determining the high temperature resistant performance of a resin. Background Art

[0002] With the development of thermal power generation, the requirements for the quality of steam water have become more stringent. Ion exchange resins are widely used in the fine treatment system of condensate and heat network hydrophobicity. However, the temperature resistance of resins has certain limits. If the water temperature entering the resin bed is too high, the exchange groups of the resin will be thermally decomposed, causing the resin skeleton to be destroyed, the strength to decrease, the wet true density to increase, and the life span to be shortened. Therefore, higher requirements are put forward for the heat resistance of the ion exchange resins used, that is, the resins are required to be able to be used for a long time at higher temperatures, with stable physical and chemical properties and excellent water quality.

[0003] At present, the method for screening high temperature resistant resins mainly refers to the "Determination Method of Heat Resistance and Antioxidant Performance of Strong Base Anion Exchange Resins for Water Treatment" (DL / T 953-2018). The specific method is to keep the OH type strong base anion exchange resin in a constant temperature water bath at 90°C for 48 hours, measure the strong group exchange capacity of the resin before and after heating, and calculate its decline rate to judge the heat resistance of the strong base anion exchange resin. This method can make a preliminary judgment on the heat resistance of the anion resin, but due to the complex conditions such as on-site temperature, regeneration acid and alkali, and treatment time, the method sets a single condition and cannot fully evaluate whether the physical and chemical properties of the resin are suitable for this site. Moreover, it is only for the heat resistance evaluation method of anion resin without cation resin, and it is even more impossible to predict the service life of the resin. If the high temperature conditions on site are simulated by extending the treatment time and changing the reaction temperature to calculate the decline rate of the strong group, a long-term dynamic test is required, which is not fast and convenient enough.

[0004] Therefore, a new method for determining the high temperature resistance of resin is proposed, which can not only better restore the high temperature conditions on site, but also more quickly judge the high temperature resistance of resin, thereby providing guidance for the screening of high temperature resistant resins and is of great significance for actual production. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for measuring the high temperature resistance of a resin.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions, including:

[0009] The transformed ion exchange resin is placed in a double-layer casing ion exchange column;

[0010] Heating: Heat pure water and 0.5-1.5 mol / L NaCl solution in a water bath, turn on the peristaltic pump switch, and circulate the pure water quickly between the exchange column and the water bath at a flow rate of 40-50 mL / min. When the temperature of the resin in the chromatography column no longer rises, remove the exchange column, shake it up and down to remove the bubbles in the resin layer;

[0011] High temperature failure: Pass NaCl solution into the exchange column, start the peristaltic pump, set the flow rate to 4-6mL / min, and after the addition of sodium chloride, pass high-temperature pure water to clean the resin, so that the resin is completely ineffective in a high temperature environment;

[0012] Cooling: drain the water in the double-layer sleeve exchange column, insert the water inlet and outlet pipes of the peristaltic pump into a beaker filled with room temperature water, turn on the peristaltic pump, and use room temperature water to cool the resin in the resin column. After the resin cools to room temperature, drain the water in the sleeve and turn off the peristaltic pump;

[0013] Resin regeneration: Use room temperature regeneration solution to pass through the exchange column at a flow rate of 5-10 mL / min to completely transform and regenerate the resin;

[0014] According to actual needs, the resin is subjected to multiple high-temperature repeated failure and regeneration treatments; after the treatments are completed, the crushing strength of the resin particles is evaluated.

[0015] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the transformed ion exchange resin is a new ion exchange resin in hydrogen or hydroxyl form.

[0016] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the transformed ion exchange resin is a new ion exchange resin in hydrogen or hydroxyl form.

[0017] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the transformation adopts the method described in GB / T 5476-2013.

[0018] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the temperature of the water bath heating is adjusted according to the temperature that the resin needs to withstand.

[0019] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the sign of the end of the cleaning in the high temperature failure is to add silver nitrate solution to clarify the water effluent from the ion exchange column.

[0020] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the regeneration liquid includes hydrochloric acid or sodium hydroxide solution.

[0021] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the concentration of the hydrochloric acid is 0.5-1.5 mol / L, and the concentration of the sodium hydroxide solution is 1-2 mol / L.

[0022] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the concentration of the hydrochloric acid is 1 mol / L, and the concentration of the sodium hydroxide solution is 2 mol / L.

[0023] As a preferred solution of the method for determining the high temperature resistance of the resin of the present invention, the resin regeneration includes cation resin regeneration and anion resin regeneration.

[0024] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the regeneration of the cationic resin includes, if the ion exchange resin before the transformation is a hydrogen-type resin, passing a room temperature hydrochloric acid solution through the exchange column at a flow rate of 4 to 5 mL / min to completely transform the resin into a chloride-type.

[0025] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the regeneration of the cationic resin includes, if the ion exchange resin before the transformation is a hydrogen-type resin, passing 250 mL of a 1 mol / L hydrochloric acid solution at room temperature through the exchange column at a flow rate of 5 mL / min to completely transform the resin into a chloride-type.

[0026] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the anion resin regeneration includes, if the ion exchange resin before the transformation is a hydroxide type resin, passing a room temperature sodium hydroxide solution through the exchange column at a flow rate of 8 to 10 mL / min to completely convert the resin into the hydroxide type.

[0027] As a preferred embodiment of the method for determining the high temperature resistance of the resin of the present invention, the anion resin regeneration includes, if the ion exchange resin before the transformation is a hydroxide type resin, passing 500 mL of a 1 mol / L sodium hydroxide solution and 500 mL of a 2 mol / L sodium hydroxide solution at room temperature through an exchange column at a flow rate of 10 mL / min respectively, so that the resin is completely converted to the hydroxide type.

[0028] Beneficial effects of the present invention:

[0029] The present invention simulates the process of on-site resin failure by treating with a high-temperature sodium chloride solution, then regenerates the resin with acid and alkali, and repeatedly restores the process of on-site resin failure and regeneration under high-temperature conditions. The heat resistance of the new resin can be quickly evaluated, and the service life of the resin can be predicted through the relationship between the number of regenerations and the crushing strength reduction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0031] Figure 1 It is a schematic diagram of the process of the present invention.

[0032] Figure 2 The crushing strength results of the resins before and after the transformation in Example 1 are distributed as follows: (a) cationic resin; (b) anionic resin. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0036] The raw materials used in the present invention are all commercially available unless otherwise specified.

[0037] The crushing strength performance test of the material prepared in the embodiment of the present invention is carried out as follows:

[0038] Start and preheat the particle strength tester, use a plastic straw to suck a screened resin onto the test bench, place the resin particle directly under the pressure head, start the pressure head, and record the pressure value displayed when the resin particle is broken. This value is the crushing strength of the resin particle.

[0039] Example 1

[0040] This embodiment provides a method for determining the high temperature resistance of a resin. Figure 1 , specifically:

[0041] A power plant uses high temperature resistant resin to treat heat network drainage. The water temperature does not exceed 80℃. Hydrochloric acid solution or sodium hydroxide solution is used for regeneration. There are 6 sets of ion exchange resins on site. Each set of resin is regenerated 4 times a year on average. It is necessary to evaluate whether the purchased high temperature resistant resin can meet the service life of 2 years. The specific operation steps are as follows:

[0042] 1) Take 25 mL of ion exchange resin and place it in a double-layer sleeve ion exchange column;

[0043] 2) Prepare 500 mL of pure water and 250 mL of 1 mol / L NaCl solution respectively and heat them to 80°C in a water bath;

[0044] 3) Turn on the peristaltic pump switch to circulate the high-temperature pure water quickly between the exchange column and the water bath at the maximum flow rate. The resin in the chromatography column is heated. At the same time, as the water temperature increases, the dissolved oxygen content in the water decreases, and bubbles are generated in the resin layer. When the temperature no longer increases, remove the exchange column and shake it up and down to remove the bubbles in the resin layer;

[0045] 4) Pass a high-temperature NaCl solution into the exchange column, start the peristaltic pump, set the flow rate to 5 mL / min, and after the addition of sodium chloride is completed, pass high-temperature pure water to clean the resin, so that the resin is completely ineffective in a high-temperature environment;

[0046] 5) After the transformation is completed, drain the high-temperature water in the double-layer sleeve exchange column, insert the inlet and outlet pipes of the peristaltic pump into a beaker filled with room temperature water, turn on the peristaltic pump, and use room temperature water to cool the resin in the resin column. After the resin cools to room temperature, drain the water in the sleeve and turn off the peristaltic pump.

[0047] 6) Regeneration of cationic resin: Use 250mL of 1mol / L hydrochloric acid solution at room temperature to pass through the exchange column at a flow rate of 5mL / min to completely convert the hydrogen-type resin to the chloride-type;

[0048] 7) Anion resin regeneration: 500 mL of 1 mol / L sodium hydroxide solution and 500 mL of 2 mol / L sodium hydroxide solution at room temperature were passed through the exchange column at a flow rate of 10 mL / min to completely convert the chlorine-type resin to the hydroxide-type;

[0049] 8) The resin is repeatedly deactivated and regenerated at high temperature for 8 times;

[0050] 9) taking out the treated ion exchange resin and measuring the crushing strength of 30 to 50 resin particles using a particle strength tester;

[0051] 10) Count the measurement results and evaluate the crushing strength of the resin.

[0052] The test results of a certain brand of high temperature resistant resin purchased by the test power plant after transformation 8 times are shown in Table 1.

[0053] Table 1 Resin crushing strength before and after transformation

[0054]

[0055] The results show that after the resin failed at high temperature and was regenerated 8 times, the crushing strength of the resin decreased due to the expansion and contraction of the resin skeleton. The average crushing strength of the positive resin decreased from 7.14N / particle to 6.99N / particle, a decrease of 2.10%, and the average crushing strength of the negative resin decreased from 10.27N / particle to 8.12N / particle, a decrease of 20.97%. It meets the requirement that the average crushing strength of the operating resin should be no less than 300g / particle (about 2.9N / particle), that is, the resin should be able to meet the service life of 2 years.

[0056] The present invention simulates the process of on-site resin failure by treating with a high-temperature sodium chloride solution, then regenerates the resin with acid and alkali, and repeatedly restores the process of on-site resin failure and regeneration under high-temperature conditions. The heat resistance of the new resin can be quickly evaluated, and the service life of the resin can be predicted through the relationship between the number of regenerations and the crushing strength reduction rate.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for determining the high temperature resistance of a resin, characterized in that: include, The transformed ion exchange resin is placed in a double-layer casing ion exchange column; Heating: Heat pure water and 0.5-1.5 mol / L NaCl solution in a water bath, turn on the peristaltic pump switch, and circulate the pure water quickly between the exchange column and the water bath at a flow rate of 40-50 mL / min. When the temperature of the resin in the chromatography column no longer rises, remove the exchange column, shake it up and down to remove the bubbles in the resin layer; High temperature failure: Pass NaCl solution into the exchange column, start the peristaltic pump, set the flow rate to 4-6mL / min, and after the addition of sodium chloride, pass high-temperature pure water to clean the resin, so that the resin is completely ineffective in a high temperature environment; Cooling: drain the water in the double-layer sleeve exchange column, insert the water inlet and outlet pipes of the peristaltic pump into a beaker filled with room temperature water, turn on the peristaltic pump, and use room temperature water to cool the resin in the resin column. After the resin cools to room temperature, drain the water in the sleeve and turn off the peristaltic pump; Resin regeneration: Use room temperature regeneration solution to pass through the exchange column at a flow rate of 5-10 mL / min to completely transform and regenerate the resin; According to actual needs, the resin is repeatedly subjected to high-temperature failure and regeneration treatments for multiple times; After the treatment, the crushing strength of the resin pellets was evaluated.

2. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The transformed ion exchange resin is a new ion exchange resin of hydrogen type or hydroxyl type.

3. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The transformation adopts the method recorded in GB / T5476-2013.

4. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The temperature of the water bath heating is adjusted according to the temperature that the resin needs to withstand.

5. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The sign of the completion of the cleaning in the high temperature failure is that the effluent from the ion exchange column is clarified by adding silver nitrate solution.

6. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The regeneration solution includes hydrochloric acid or sodium hydroxide solution.

7. The method for determining the high temperature resistance of a resin according to claim 1 or 5, characterized in that: The concentration of the hydrochloric acid is 0.5-1.5 mol / L, and the concentration of the sodium hydroxide solution is 1-2 mol / L.

8. The method for determining the high temperature resistance of a resin according to claim 1, wherein: The resin regeneration includes cation resin regeneration and anion resin regeneration.

9. The method for determining the high temperature resistance of a resin according to claim 7, wherein: The regeneration of the cation resin includes, if the ion exchange resin before the transformation is a hydrogen-type resin, passing a room temperature hydrochloric acid solution through the exchange column at a flow rate of 4-5 mL / min to completely transform the resin into a chloride-type.

10. The method for determining the high temperature resistance of a resin according to claim 7, wherein: The anion resin regeneration includes, if the ion exchange resin before transformation is a hydroxide type resin, passing a room temperature sodium hydroxide solution through an exchange column at a flow rate of 8-10 mL / min to completely transform the resin into a hydroxide type.

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