Preparation method and application of modified resin inhibitor for reducing acid regurgitation of acetate in storage process

Abstract

The invention provides a preparation method and application of a modified resin inhibitor for reducing acid regurgitation of acetate in the storage process, macroporous adsorption resin is modified to obtain the modified resin inhibitor, the preparation method comprises the following steps: S1, the macroporous adsorption resin and a nano inorganic material are mixed and heated, and a mixture is obtained; paraformaldehyde and hydrogen chloride are added for a reaction, and an intermediate product is obtained; and S2, adding triethanolamine into the intermediate product, and reacting to obtain the modified resin inhibitor. The prepared modified resin inhibitor can effectively reduce acid regurgitation and moisture in the storage process of acetate, guarantees the quality of acetate, is easy to operate, easy to separate, free of pollution, long in service life and not prone to inactivation, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of acetate production, and mainly to a preparation method and application of a modified resin inhibitor for reducing acid regurgitation of acetate during storage. Background Art

[0002] Acetate products are widely used in the fields of solvents, plasticizers, surfactants and polymer monomers. Among the technical indicators of acetate, water content and acid content are important test items. If they exceed certain indicators, the performance of downstream products will be affected. Therefore, during the production process, the water content and acid content of the acetate coming out of the distillation tower and entering the finished product metering tank must be strictly controlled by adjusting the process conditions. However, after entering the product storage tank from the finished product metering tank, the acid content may increase after a long storage time. This phenomenon is generally called acid reflux. Due to the large volume of the storage tank, once acid reflux occurs, the acid content cannot be quickly reduced and needs to be returned to the refining system for reprocessing. Not only is the processing volume large, but it also increases energy consumption and is difficult to operate.

[0003] Controlling the moisture and acid content by adjusting the production process cannot completely remove trace moisture and acidic substances in acetate products. The stored acetate still contains a certain amount of moisture and acidic substances, which creates conditions for the acetate to undergo acid reversion during storage. Therefore, it is necessary to control the moisture and acid content in acetate. Ordinary water-absorbent resins cannot remove acid in a targeted manner and may absorb more acetate while removing acid. If used for a long time, they will lose their function due to swelling. Chemical deacidifiers cannot absorb moisture, and using both at the same time is not easy to operate and difficult to separate from acetate.

[0004] In summary, it is necessary to develop a new technical solution to solve the defects and shortcomings in the existing technology. Summary of the invention

[0005] The present invention provides a preparation method of a modified resin inhibitor for reducing acid regurgitation of acetate during storage and application thereof. The modified resin inhibitor prepared by the preparation method of the modified resin inhibitor for reducing acid regurgitation of acetate during storage can simultaneously react with water and acid in acetate to reduce the content of water and acid.

[0006] An object of the present invention is to provide a method for preparing a modified resin inhibitor for reducing acid regurgitation of acetate during storage, the method comprising the following steps:

[0007] S1, mixing a macroporous adsorption resin and a nano-inorganic material and heating them, adding paraformaldehyde and hydrogen chloride to react, and obtaining an intermediate product;

[0008] S2. Add triethanolamine to the intermediate product to react to obtain a modified resin inhibitor.

[0009] Furthermore, in step S1, the nano inorganic material is selected from one or more of natural sodium montmorillonite powder, nano silicon dioxide, and nano sefoam.

[0010] Furthermore, in step S1, the particle size of the nano inorganic material is 1-20 nm.

[0011] Furthermore, in step S1, the macroporous adsorption resin is selected from a strongly basic styrene-based anion exchange resin.

[0012] Furthermore, in steps S1 and S2, the mass ratio of the macroporous adsorption resin, nano-inorganic material, paraformaldehyde, hydrogen chloride and triethanolamine is (2-5):1:(1-2):(0.3-0.6):(2-2.5).

[0013] Furthermore, in step S1, the heating temperature is 50-70°C.

[0014] Furthermore, in step S1, the reaction time is 4-8 hours.

[0015] Furthermore, in step S2, the reaction temperature is 50-70°C.

[0016] Furthermore, in step S2, the reaction time is 0.5-1.5h.

[0017] Furthermore, the modified resin inhibitor needs to be pretreated before use, and the pretreatment includes the following steps:

[0018] L1. Wash the modified resin inhibitor in 50-60℃ water, change the water every 15 minutes, change the water 4-5 times, and then change the water every 30 minutes, a total of 7-8 times, until the water is not brown and there is little foam;

[0019] L2, slowly flow 1mol / L NaOH aqueous solution through the modified resin inhibitor, the volume of the solution is about 2-3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0020] L3, washing the modified resin inhibitor with water having a pH value of about 9, and then flowing a 5wt% NaCl aqueous solution through the modified resin inhibitor, the volume of the solution being about 3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of the solution flowing through per hour;

[0021] L4, flow 1 mol / L HCl aqueous solution through the modified resin inhibitor, the volume of the solution is about 2-3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0022] L5. Rinse the modified resin inhibitor with water until the pH value of the effluent is about 5;

[0023] L6, flow 1mol / L NaOH aqueous solution through the modified resin inhibitor, the volume of the solution is about 3-5 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0024] L7. Rinse the modified resin inhibitor with deionized water until the pH value of the effluent is greater than 8.

[0025] Another object of the present invention is to provide the use of the modified resin inhibitor prepared by the preparation method of the modified resin inhibitor for reducing the acid regurgitation of acetate during storage in the storage of acetate.

[0026] Furthermore, the method for using the modified resin inhibitor after pretreatment comprises the following steps:

[0027] Add 0.01% of the modified resin inhibitor to the acetate finished product storage tank, and replenish it every 60 days. Empty and clean the acetate finished product storage tank at least once a year, remove the modified resin inhibitor in the tank, and add the modified resin inhibitor again after cleaning.

[0028] Furthermore, the acetate includes ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate and mixed butyl acetate.

[0029] The present invention has the following beneficial effects:

[0030] 1. The present invention mixes natural sodium montmorillonite powder with a strong alkaline styrene-based anion exchange resin for modification, and inserts part of the resin monomers into the natural sodium montmorillonite powder interlayer by a solution intercalation polymerization method for polymerization to form a modified resin composite material, thereby improving the mechanical strength and thermal stability, making it difficult to be damaged after swelling, and extending the service life; moreover, metal ions such as iron ions and calcium ions contained in acetate will inactivate the resin. After the strong alkaline styrene-based anion exchange resin is modified by doping with natural sodium montmorillonite powder, the metal ions are adsorbed and replaced, making the resin difficult to be deactivated, and extending the service life.

[0031] 2. The present invention first uses paraformaldehyde to react with a strong basic anion exchange resin and concentrated hydrochloric acid to generate an intermediate product by chloromethylation, and then uses triethanolamine to react with the intermediate product chloromethyl polystyrene to generate a quaternization reaction, so that part of the hydroxyl groups in the triethanolamine are converted into quaternary ammonium groups to generate a modified strong basic styrene anion exchange resin. The triethanolamine contains three hydrophilic hydroxyl groups and can absorb a large amount of water. After being grafted with the strong basic styrene anion exchange resin, the hydroxyl groups that are not cross-linked improve the water absorption capacity of the product modified resin inhibitor, and the modified resin inhibitor is immiscible and non-reactive with acetate, and is easy to separate.

[0032] 3. The modified strong basic styrene anion exchange resin of the present invention contains a quaternary ammonium strong basic group, which can react with acidic substances to neutralize and remove acidic H + , reducing the acid regurgitation of acetate during storage. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0034] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0035] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0036] The following raw materials are used in the embodiments of the present invention:

[0037] 201×7 strong basic anion exchange resin was purchased from Ningbo Zhengguang Resin Co., Ltd.;

[0038] Natural sodium montmorillonite powder, particle size 1-5nm;

[0039] Paraformaldehyde, molecular formula: (CH2O) n , n = 10-100, reagent grade, mass fraction 95%, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0040] Concentrated hydrochloric acid was of analytical grade, with a mass fraction of 37%.

[0041] Example 1

[0042] A modified resin inhibitor for reducing the acid regurgitation of acetate during storage, wherein the preparation method comprises the following steps:

[0043] S1, add 350g 201×7 strong basic anion exchange resin and 100g natural sodium montmorillonite powder to 500g anhydrous ethanol solvent, mix and heat to 60°C, add 150g paraformaldehyde and 120g concentrated hydrochloric acid, mix well, react for 6h, and obtain an intermediate product;

[0044] S2. Add 250 g of triethanolamine to the intermediate product for 1 hour, maintain the temperature at 60° C., stir and react for 2 hours, then cool to 25° C. and filter to obtain a modified resin inhibitor.

[0045] Example 2

[0046] A modified resin inhibitor for reducing the acid regurgitation of acetate during storage, wherein the preparation method comprises the following steps:

[0047] S1, 350g 201×7 strong basic anion exchange resin and 100g natural sodium montmorillonite powder were added to 500g anhydrous ethanol solvent, mixed and heated to 60°C, 100g paraformaldehyde and 120g concentrated hydrochloric acid were added and mixed evenly, and the mixture was reacted for 6h to obtain an intermediate product;

[0048] S2. Add 250 g of triethanolamine to the intermediate product for 1 hour, maintain the temperature at 60° C., stir and react for 2 hours, then cool to 25° C. and filter to obtain a modified resin inhibitor.

[0049] Example 3

[0050] A modified resin inhibitor for reducing the acid regurgitation of acetate during storage, wherein the preparation method comprises the following steps:

[0051] S1, add 250g 201×7 strong basic anion exchange resin and 100g natural sodium montmorillonite powder to 500g anhydrous ethanol solvent, mix and heat to 60°C, add 150g paraformaldehyde and 120g concentrated hydrochloric acid, mix well, react for 6h, and obtain an intermediate product;

[0052] S2. Add 200 g of triethanolamine to the intermediate product for 1 hour, maintain the temperature at 60° C., stir and react for 2 hours, then cool to 25° C. and filter to obtain a modified resin inhibitor.

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 1 is that in step S1, 201×7 strong basic anion exchange resin is replaced by D301 weak basic anion exchange resin, and the other components are the same as the preparation method.

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that in step S1, the natural sodium montmorillonite powder with a particle size of 1-5 nm is replaced by natural sodium bentonite with a particle size of 1-5 nm, and the other components are the same as the preparation method.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 1 is that in step S1, natural sodium montmorillonite powder is not added, and in step S2, after cooling to 25° C., the filtered product and natural sodium montmorillonite powder are mixed and stirred uniformly in a mass ratio of 5:1 to obtain a modified resin inhibitor.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 1 is that in step S2, triethanolamine is replaced by triethylamine, and the other components are the same as the preparation method.

[0061] Application Examples

[0062] The modified resin inhibitor needs to be pretreated before use. The pretreatment includes the following steps:

[0063] L1. Wash the modified resin inhibitor in 50℃ water, changing the water every 15 minutes. After changing the water 5 times, change the water every 30 minutes, a total of 8 times, until the water is not brown and there is little foam;

[0064] L2, slowly flow 1mol / L NaOH aqueous solution through the modified resin inhibitor, the volume of the solution is about 3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0065] L3, washing the modified resin inhibitor with water having a pH value of about 9, and then flowing a 5wt% NaCl aqueous solution through the modified resin inhibitor, the volume of the solution being about 3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of the solution flowing through per hour;

[0066] L4, flow 1 mol / L HCl aqueous solution through the modified resin inhibitor, the volume of the solution is about 3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0067] L5. Rinse the modified resin inhibitor with water until the pH value of the effluent is about 5;

[0068] L6, flow 1 mol / L NaOH aqueous solution through the modified resin inhibitor, the volume of the solution is about 3 times the volume of the modified resin inhibitor, and 1.5 times the bed volume of solution flows through every hour;

[0069] L7. Rinse the modified resin inhibitor with deionized water until the pH value of the effluent is greater than 8.

[0070] The method for using the modified resin inhibitor after pretreatment comprises the following steps:

[0071] Add 0.01% of the modified resin inhibitor to the acetate finished product storage tank, and replenish it every 60 days. Empty and clean the acetate finished product storage tank at least once a year, remove the modified resin inhibitor in the tank, and add the modified resin inhibitor again after cleaning.

[0072] Test Example 1

[0073] Determination of the effect of modified resin inhibitors on the acidity of acetate esters.

[0074] Test method:

[0075] The effects of the modified resin inhibitors prepared in Examples 1-3 and Comparative Examples 1-4 on the acidity of acetate were determined in accordance with the provisions of GB / T12717-2007.

[0076] Under normal production conditions of acetate, 0.01% of the modified resin inhibitor prepared in Examples 1-3 and Comparative Examples 1-4 was added to 7 acetate product storage tanks, respectively. After 60 days, samples were taken from the acetate product storage tanks, and 7 portions of acetate, each with 25 ml, were taken. The samples were placed in colorimetric tubes and sealed. The samples were heated in a water bath at 70° C. for 72 h. The acidity was measured after cooling to room temperature, and the acid regurgitation rate of the acetate was calculated. The lower the acid regurgitation rate, the better the effect of the modified resin inhibitor in reducing acid regurgitation.

[0077] The calculation formula of acid reflux rate X is as follows:

[0078]

[0079] in,

[0080] V0-72 hours of constant temperature heating before the acidity of acetate (the mass fraction of acid in acetate, calculated as acetic acid), the unit is percentage (%);

[0081] V1-72 hours of constant temperature heating after the acidity of acetate (the mass fraction of acid in acetate, calculated as acetic acid), the unit is percentage (%).

[0082] The test results are shown in Table 1.

[0083] Table 1 Inhibitory effect of modified resin inhibitors prepared in Examples 1-3 and Comparative Examples 1-4 on acid reflux

[0084] Initial acidity (wt%) Acidity after 72h (wt%) Acid reflux rate (%) Example 1 0.0012 0.0013 8.3 Example 2 0.0011 0.0012 9.1 Example 3 0.0011 0.0012 9.1 Comparative Example 1 0.0012 0.0020 66.7 Comparative Example 2 0.0012 0.0017 41.7 Comparative Example 3 0.0011 0.0018 63.6 Comparative Example 4 0.0012 0.0016 33.3

[0085] It can be seen from Table 1 that the acid regurgitation rates of Examples 1-3 are very low, only 8.3, 9.1, and 9.1%, respectively, indicating that the modified resin inhibitor has good performance in inhibiting the acid regurgitation of acetate during storage.

[0086] In Comparative Example 1, the 201×7 strong alkaline anion exchange resin is replaced with the D301 weak alkaline anion exchange resin. The prepared modified resin inhibitor has a high acid regurgitation rate after use, reaching 66.7%. This is because the modified resin inhibitor has a weak alkalinity. Although it is easy to neutralize with a strong acidic substance, it is not easy to neutralize with a weakly acidic substance. Therefore, the obtained modified resin inhibitor has a poor effect in reducing acid regurgitation.

[0087] In Comparative Example 2, the natural sodium montmorillonite powder with a particle size of 1-5 nm is replaced by natural sodium-based bentonite with a particle size of 1-5 nm. Natural bentonite is a mineral with montmorillonite as the main mineral component, and its montmorillonite content is 85-90%. The acid regurgitation rate after the modified resin inhibitor is used is relatively high, reaching 41.7%. This is because the natural bentonite contains a small amount of impurities. The presence of impurities weakens its adsorption capacity, thereby making its effect of reducing acid regurgitation poor.

[0088] In Comparative Example 3, natural sodium montmorillonite powder was not added in step S1, and the filtered product was mixed and stirred evenly with the natural sodium montmorillonite powder after cooling to 25° C. in step S2. The acid regurgitation rate after the modified resin inhibitor was used was high, reaching 63.6%. This is because the natural sodium montmorillonite powder was only physically blended with other raw materials, and the resin monomer did not form a composite material with the natural sodium montmorillonite powder through solution intercalation polymerization, and the adsorption effect was weakened. Therefore, the effect of reducing acid regurgitation was poor.

[0089] In Comparative Example 4, the triethanolamine in step S2 was replaced by triethylamine. The acid regurgitation rate of the modified resin inhibitor increased significantly to 33.3% after use. This may be due to the reduced activity of the modified resin inhibitor. Therefore, the effect of reducing acid regurgitation is weaker than that of the modified resin inhibitor with the addition of triethanolamine.

[0090] Test Example 2

[0091] Determination of the effect of modified resin inhibitors on the water content of acetates.

[0092] Test method:

[0093] Place a certain mass of modified resin inhibitor particles evenly on a surface dish, put it in an oven at 105℃±2℃, keep it at constant temperature for more than 4 hours until the mass no longer changes, weigh about 1g of resin in a laboratory environment with a temperature of 25℃±5℃ and a relative humidity of 50%±5%, accurate to 0.001g, record the mass as W1, pour it into a beaker filled with 1000mL of distilled water, let it stand for 60min, take it out and filter the water with a sieve, let it stand for 30min, weigh it and record it as W2. The test results are calculated according to the following formula:

[0094]

[0095] in,

[0096] W1-mass of resin before water absorption, in grams (g);

[0097] W2 - the mass of the resin after absorbing water, in grams (g).

[0098] The test results are shown in Table 2.

[0099] Table 2 Water adsorption effect of modified resin inhibitors of Examples 1-3 and Comparative Examples 1-4

[0100]

[0101] It can be seen from Table 2 that the water absorption rates of Examples 1-3 are all above 90%, indicating that the modified resin contains more hydrophilic hydroxyl groups and can absorb a large amount of water.

[0102] In Comparative Example 1, the 201×7 strong basic anion exchange resin was replaced with the D301 weak basic anion exchange resin. Since the D301 weak basic anion exchange resin is not prone to cross-linking reaction and has fewer hydrophilic groups in its polymer structure, its water absorption capacity is weaker.

[0103] In Comparative Example 2, the natural sodium montmorillonite powder with a particle size of 1-5 nm is replaced by natural sodium bentonite with a particle size of 1-5 nm. Although the natural sodium bentonite has more impurities than the natural sodium montmorillonite powder, the water absorption performance of the formed modified resin composite material is basically not affected by impurities, and a strong water absorption capacity is retained.

[0104] In Comparative Example 3, no natural sodium montmorillonite powder is added in step S1, and the filtered product is evenly mixed with the natural sodium montmorillonite powder after cooling to 25° C. in step S2. The natural sodium montmorillonite powder is only physically blended with other raw materials without forming a composite structure, and its water absorption capacity is not strong.

[0105] In Comparative Example 4, the triethanolamine in step S2 is replaced by triethylamine, and the resulting modified resin composite material substantially does not contain hydrophilic group hydroxyl groups, so its water absorption capacity is relatively weak.

[0106] In summary, the ability of modified resin inhibitors to reduce acid reflux mainly depends on their ability to neutralize acid and remove acid. When the water absorption capacity is strong, it can also inhibit the hydrolysis of acetate to generate acid to a certain extent.

[0107] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0108] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage, It is characterized in that The method for preparing the modified resin inhibitor for reducing the acid regurgitation of acetate during storage comprises the following steps: S1, mixing a macroporous adsorption resin and a nano-inorganic material and heating them, adding paraformaldehyde and hydrogen chloride to react, and obtaining an intermediate product; S2. Add triethanolamine to the intermediate product to react and obtain a modified resin inhibitor.

2. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that The nano inorganic material is selected from one or more of natural sodium montmorillonite powder, nano silicon dioxide and nano seafoam.

3. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 2, It is characterized in that The particle size of the nano inorganic material is 1-20 nm.

4. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that The macroporous adsorption resin is selected from strongly basic styrene-based anion exchange resin.

5. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that The mass ratio of the macroporous adsorption resin, nano-inorganic material, paraformaldehyde, hydrogen chloride and triethanolamine is (2-5):1:(1-2):(0.3-0.6):(2-2.5).

6. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that In step S1, the heating temperature is 50-70°C.

7. The method for preparing a modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that In step S1, the reaction time is 4-8 hours.

8. The method for preparing the modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that In step S2, the reaction temperature is 50-70°C.

9. The method for preparing the modified resin inhibitor for reducing the acid regurgitation of acetate during storage according to claim 1, It is characterized in that In step S2, the reaction time is 0.5-1.5h.

10. Use of the modified resin inhibitor prepared by the method for preparing the modified resin inhibitor for reducing acid regurgitation of acetate during storage according to any one of claims 1 to 9 in the storage of acetate.

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