Comb-type copolymer dispersant butter inhibitor

Abstract

The invention discloses a comb-type copolymer dispersant butter inhibitor, and belongs to the technical field of chemical engineering. Aiming at the technical problem that butter is easy to generate, not easy to disperse and not easy to discharge out of an alkaline washing tower in the process of preparing ethylene through cracking, the invention provides the comb-shaped copolymer, structures such as DOTA, phenolic hydroxyl groups and benzene rings are introduced into the structure of the comb-shaped copolymer, and a polymerization reaction can be prevented from generating butter through the effects of oxidation resistance, metal ion chelation, similar compatibility and the like; the invention also provides a butter inhibitor which comprises a polymerization inhibitor, an antioxidant, a comb copolymer, a surfactant and a solvent. Generation of butter can be effectively reduced, the butter is promoted to be dispersed and discharged out of the alkaline washing tower, and the technical effect of effectively reducing the pressure difference can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and specifically to a comb copolymer dispersant butter inhibitor. Background Art

[0002] During the process of ethylene production by pyrolysis, a large amount of acidic gases such as H2S and CO2 are generated. Through the caustic washing process, polymers will be produced during the caustic washing of the pyrolysis gas. These polymers are liquids and are prone to form a yellow viscous state when in contact with air, which is usually called "butter". It will seriously affect the normal operation of the caustic washing tower and the caustic washing effect, consume a large amount of caustic liquor, and at the same time, a large amount of butter is prone to polymerize and scale, blocking the distributors and fillers in the tower, resulting in tower blockage, shortening the operation cycle of the caustic washing tower.

[0003] The mechanism of butter formation includes: First, during the caustic washing of the pyrolysis gas, diolefins or other unsaturated hydrocarbons are prone to form free radicals under the action of trace oxygen and metal ions, and cross-linked polymers are generated by the free radicals. Second, aldehydes or ketones in the pyrolysis gas cause aldol condensation or alcohol aldol condensation (Aldol Condensation) reactions under the action of alkali. That is, aldehydes or ketones with active hydrogen atoms on the ɑ-position carbon atoms of two molecules can undergo an addition reaction under the action of alkali to form β-carbonyl aldehydes, and further add up to polymers with a certain molecular weight.

[0004] The prior art CN110294662A provides a butter inhibitor mixed with diethylhydroxylamine, imidazoline, and ammonium dihydrogen phosphate. This inhibitor forms a protective film on the inner wall of the caustic washing tower by the adsorption of imidazoline, and has a relatively good inhibitory effect mainly on free radical polymerization. However, this method still uses a large amount of polymerization inhibitors and cannot effectively increase the dispersibility of butter.

[0005] The prior art CN118108567A discloses a butter inhibitor for the MTO caustic washing tower, including the following components in mass percentage: diethylhydroxylamine, ammonium dihydrogen phosphate, sodium gluconate, hydroxylamine sulfate, phytate, quaternized polyethyleneimine, guanidinized polyethyleneimine, DMF, carbohydrazide, water; according to the test data records, although the above method can effectively reduce the output of polymers, it is still difficult to increase the dispersibility of butter, which is not conducive to the discharge of the generated butter and will still increase the pressure difference.

[0006] The aggregation of butter in the caustic liquor is likely to cause blockage of the caustic washing tower, and in severe cases, the device will stop running. Therefore, in view of the technical problems existing in the prior art, it is still urgent to develop a more effective butter inhibitor. Summary of the Invention

[0007] In order to overcome the deficiencies of the above prior art, the present invention provides a comb copolymer dispersant butter inhibitor.

[0008] The technical solution for achieving the object of the present invention is as follows: A comb-shaped copolymer dispersant, characterized in that it has the following structural formula (I), (I), where m and n are any integers selected from 5 to 100, and the molar ratio of monomers A, B, and C for preparing the copolymer is x:y:z = (4 - 7):(3 - 5):(3 - 8).

[0009] The preparation method of the copolymer of formula (I) is as follows: S1: Synthesis of monomer A: Under a nitrogen atmosphere, dissolve 3,4-dihydroxy mandelic acid in the solvent anhydrous DMF (N,N-dimethylformamide), and sequentially add EDC and NHS, and stir for activation to obtain a 3,4-dihydroxy mandelic acid activation solution; Drop the 3,4-dihydroxy mandelic acid activation solution into the solution of polyethylene glycol diamine (H2N-PEGm-NH2), stir, and react fully to obtain a 3,4-dihydroxy mandelic acid-modified polyethylene glycol compound; Dissolve acrylic acid in a phosphate buffer solution with pH 5.5, add EDC and NHS, and stir at room temperature for 1 hour to fully activate the carboxyl group of acrylic acid to form an acrylic acid carboxyl activation solution.

[0010] Dissolve the 3,4-dihydroxy mandelic acid-modified polyethylene glycol compound in a phosphate buffer solution with pH 5.5, add the acrylic acid carboxyl activation solution thereto, stir and react fully to obtain monomer A.

[0011] The molar dosage ratio of 3,4-dihydroxy mandelic acid, polyethylene glycol diamine, and acrylic acid is (1 - 1.1):(1 - 1.05):(0.95 - 1).

[0012] S2: Synthesis of monomer B: Dissolve polyethylene glycol diamine (NH2-PEGn-NH2) in a phosphate buffer solution, and under stirring conditions, dropwise add a DOTA-NHS ester solution, and stir and react fully to obtain a DOTA-PEG-NH2 solution; Dissolve acrylic acid in a phosphate buffer solution with pH 5.5, add EDC and NHS, and stir at room temperature for 1 hour to fully activate the carboxyl group of acrylic acid to form an acrylic acid carboxyl activation solution; Drop the acrylic acid carboxyl activation solution into the DOTA-PEG-NH2 solution, and stir and react fully to obtain monomer B.

[0013] The molar dosage ratio of DOTA-NHS, polyethylene glycol diamine, and acrylic acid is (1 - 1.1):(1 - 1.05):(1 - 0.95).

[0014] S3: Under a nitrogen atmosphere, monomers A, B, and C are dissolved in an isopropanol solution, heated and stirred, and the temperature is raised to 85 °C. 2,2'-Azobis(2-methylbutyronitrile) is dissolved in isopropanol and added to the reaction system. The reaction is carried out for 4 hours. Subsequently, the initiator 2,2'-azobis(2-methylbutyronitrile) is supplemented and added, and the reaction continues for 4 h. Then the reaction is stopped, followed by dialysis purification and freeze-drying; the molar dosage ratio of monomers A, B, and C is (4-7):(3-5):(3-8).

[0015] The present invention also provides a butter inhibitor, which, by weight, comprises: 3-8 parts of a polymerization inhibitor, 1-10 parts of an antioxidant, 5-16 parts of a comb-shaped copolymer dispersant, 3-5 parts of a surfactant, and 50-80 parts of deionized water.

[0016] The polymerization inhibitor is selected from at least one of propanolamine, isopropanolamine, and hydrazine hydrate.

[0017] The antioxidant is selected from at least one of N,N-diethylhydroxylamine and sodium thiosulfate.

[0018] The surfactant is selected from at least one of sodium dodecylbenzenesulfonate and alkylphenol polyoxyethylene ether.

[0019] Beneficial effects

[0020] The present invention provides a butter inhibitor of a comb-shaped copolymer dispersant, which can effectively reduce the formation of butter in the caustic scrubber, and can effectively enhance the dispersion of butter, and then discharge it from the caustic scrubber, which can effectively reduce the pressure difference and extend the operation cycle.

[0021] The present invention provides a comb-shaped copolymer dispersant, and the copolymer is formed by copolymerizing monomer A, monomer B, and monomer C. Polyethylene glycol long chains with compatibilizing effects are introduced into monomers A and B, which can effectively enhance the water solubility of the dispersant in the caustic scrubber. Secondly, 3,4-dihydroxymandelic acid is introduced into monomer A. It has two phenolic hydroxyl groups and has antioxidant activity, which can reduce the oxygen content in the caustic solution, reduce the generation of free radicals caused by oxidation reactions, and after the phenolic hydroxyl groups are oxidized, benzoquinone substances are generated. The benzoquinone substances can combine with free radicals to prevent free radical reactions and effectively reduce the amount of butter generated by free radical reactions. Moreover, 3,4-dihydroxymandelic acid has a benzene ring and is hydrophobic. It can enhance the dispersibility of the already generated butter through the principle of similar compatibility and the π-π conjugation effect of the benzene ring. DOTA is introduced into monomer B. DOTA has structures with multiple carboxyl groups and amines and has a strong chelating effect on metal ions, which can effectively reduce the content of metal ions in the caustic solution, thereby reducing the catalytic effect of metal ions on free radical reactions and reducing the generation of butter. Moreover, DOTA is highly water-soluble and can improve the hydrophilicity of the comb-shaped copolymer dispersant. Monomer C has a benzene ring, which can effectively adjust the hydrophobicity of the comb-shaped copolymer dispersant, effectively adjust the amphiphilicity of the high comb-shaped copolymer dispersant, and enhance the dispersibility of butter.

[0022] The butter inhibitor provided by the present invention contains a comb-shaped copolymer dispersant, a polymerization inhibitor, and a surfactant, which can effectively cooperate and synergistically inhibit the generation of butter and improve the dispersion degree of butter. Brief Description of the Drawings

[0023] Figure 1 It is the infrared spectrum diagram of the comb-shaped copolymer dispersant.

[0024] Figure 2 It is the synthesis route diagram of the comb-shaped copolymer dispersant. Detailed Embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0026] Now, the raw materials used in the examples and comparative examples are described as follows: 3,4-Dihydroxymandelic acid: Purchased from Shanghai Yuanye Bio-Technology Co., Ltd.

[0027] 2,2'-Azobis(2-methylbutyronitrile): Purchased from Hubei Xinjiecheng Chemical Technology Co., Ltd.

[0028] DOTA-NHS: purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0029] The component raw materials used in each parallel experiment or comparative experiment are all of the same type, and the experimental methods adopted are all carried out under the same conditions. Except for the homemade comb-type copolymer dispersant, other chemical raw materials are all commercially available raw materials.

[0030] The comb copolymer dispersant is prepared by the following method: S1: Synthesis of Monomer A: Under nitrogen atmosphere, 3,4-dihydroxymandelic acid was dissolved in anhydrous DMF (N,N-dimethylformamide) solvent, EDC and NHS were added in sequence, and stirred for activation to obtain a 3,4-dihydroxymandelic acid activated solution; the molar ratio of 3,4-dihydroxymandelic acid, EDC, and NHS was 1:1:1.1; The activated 3,4-dihydroxymandelic acid solution was added dropwise to the polyethylene glycol diamine (H2N-PEG9-NH2) DMF solution, stirred, reacted fully, and freeze-dried to obtain a polyethylene glycol compound modified with 3,4-dihydroxymandelic acid; the molar ratio of 3,4-dihydroxymandelic acid to polyethylene glycol diamine was 1.1:1.05; Acrylic acid was dissolved in a phosphate buffer solution at pH 5.5, EDC and NHS were added, and the mixture was stirred at room temperature for 1 hour to fully activate the carboxyl group of acrylic acid to form an acrylic acid carboxyl group activation solution; the molar ratio of acrylic acid, EDC and NHS was 1:1:1.1.

[0031] The polyethylene glycol compound modified with 3,4-dihydroxymandelic acid is dissolved in a phosphate buffer solution at pH 7.4, and the acrylic acid carboxyl activation solution is added thereto, and stirred to react sufficiently to obtain monomer A.

[0032] The molar ratio of 3,4-dihydroxymandelic acid, polyethylene glycol diamine and acrylic acid is 1.1:1.05:0.95.

[0033] S2: Synthesis of monomer B: Dissolve polyethylene glycol diamine (NH2-PEG9-NH2) in pH 7.4 phosphate buffer, add DOTA-NHS ester solution dropwise under stirring, stir well to react, and obtain DOTA-PEG9-NH2 solution; the molar ratio of DOTA-NHS to polyethylene glycol diamine is 1.1:1.05; Dissolve acrylic acid in phosphate buffer solution with pH 5.5, add EDC and NHS, stir at room temperature for 1 hour to fully activate the carboxyl group of acrylic acid, and form an activated solution of acrylic acid carboxyl group; drop the activated solution of acrylic acid carboxyl group into DOTA-PEG9-NH2 solution, stir and react fully to obtain monomer B; the molar dosage ratio of DOTA-NHS, polyethylene glycol diamine, and acrylic acid is 1.1:1.05:0.95.

[0034] S3: Under a nitrogen atmosphere, dissolve monomer A, monomer B, and monomer C in isopropanol solution, heat and stir, raise the temperature to 85 °C, dissolve 2,2'-azobis(2-methylbutyronitrile) in isopropanol and add it to the reaction system, react for 4 hours, subsequently supplement and add the initiator 2,2'-azobis(2-methylbutyronitrile), continue to react for 4 h, stop the reaction, dialyze and purify, and freeze-dry. The molar dosage ratio of monomer A, monomer B, and monomer C is 5:5:3.

[0035] The infrared spectrum of the comb copolymer prepared by the above specific method is shown in Figure 1 ; Figure 1 It shows that: the amide peak is at 1673 cm -1 , the stretching vibration of the phenolic C-O bond appears at 1240 cm -1 , the broad peak of the stretching vibration of the phenolic hydroxyl group appears between 3200 - 3550 cm -1 , and the characteristic peak of the C-C stretching vibration of the benzene ring appears at about 1600 cm -1 .

[0036] Examples 1 - 4 A butter inhibitor, characterized in that, by weight, it contains: hydrazine hydrate (polymerization inhibitor) 3 - 8 parts, N,N-diethylhydroxylamine (antioxidant) 1 - 10 parts, comb copolymer dispersant (self-made) 5 - 16 parts, sodium dodecylbenzenesulfonate (surfactant) 3 - 5 parts, deionized water 50 - 80 parts, mix according to the ratio and stir evenly.

[0037] Comparative Examples 1 - 4 The preparation method is the same as that of Examples 1 - 4, except that the components or dosages of the butter inhibitor are adjusted.

[0038] Table 1 Formulation table of butter inhibitors in Examples 1 - 4 and Comparative Examples 1 - 4

[0039] Performance detection test of the butter inhibitor: The gas injection volume of the caustic scrubber is 120 t / h. Inject the butter inhibitors of Examples 1 - 4 and Comparative Examples 1 - 4 into the caustic scrubber by an electromagnetic pump. The injection volume of the butter inhibitor is 80 kg / h. The device runs for 168 h, and calculate the content of the polymer in the caustic solution. The calculation method is as follows: 1) Polymer content in the lye: Record the mass of the lye sample taken from the 5L caustic scrubber as M1. After filtering through three layers of filter paper, remove the filter paper together with the solid product and dry it at 60°C for 3 hours to obtain the dried material (M2). The mass of the three-layer filter paper is M3. Calculate the polymer content in the lye according to the following formula; Polymer content in the lye % = (M2 - M3) / M1 × 100%.

[0040] 2) Pressure difference of the caustic scrubber: Record the pressure values of the pressure gauges at the top and bottom of the tower at 168 hours and calculate the pressure difference.

[0041] Table 2 Test results of the performance detection of the butter inhibitor

[0042] From the test results of the performance detection of the butter inhibitor in Table 2, it can be seen that the butter inhibitors described in Examples 1-4 can effectively reduce the content of polymers (butter) and the pressure difference of the caustic scrubber. From Comparative Example 3, it can be seen that in the absence of the action of the comb copolymer dispersant, the content of polymers and the pressure difference increase significantly, which fully proves that the comb copolymer dispersant has a significant effect of reducing polymer polymerization, and at the same time can also increase polymer dispersion, helping the polymers to be discharged with the alkaline water and reducing the adhesion to the caustic scrubber and increasing the pressure difference; from Comparative Example 1, it can be seen that in the absence of the action of the polymerization inhibitor, the content of polymers and the pressure difference are also relatively small, further confirming the role of the comb copolymer dispersant in preventing polymerization and reducing the pressure difference. From Comparative Examples 2 and 4, it can be seen that the effects of the antioxidant and the surfactant are relatively weak, but the antioxidant can enhance the antioxidant effect of the butter inhibitor and further prevent the free radical polymerization reaction, and the surfactant can further enhance the dispersion performance of the polymers (butter), thereby reducing the pressure difference.

[0043] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the relevant technical fields can understand and utilize the present invention well.

Claims

1. A comb-shaped copolymer dispersant, characterized in that, It has the following structural formula (I), (I), m and n are selected from any integers of 5 to 100, and the molar ratio of monomers A, B, and C for preparing the copolymer is x:y:z = (4 - 7):(3 - 5):(3 - 8).

2. The comb copolymer dispersant according to claim 1, characterized in that: The preparation method of the comb-shaped copolymer dispersant is as follows, S1: Synthesis of monomer A: Under a nitrogen atmosphere, dissolve 3,4-dihydroxy mandelic acid in the solvent anhydrous N,N-dimethylformamide (DMF), and successively add EDC and NHS, and stir for activation to obtain a 3,4-dihydroxy mandelic acid activation solution; Drop the 3,4-dihydroxy mandelic acid activation solution into the polyethylene glycol diamine H2N-PEGm-NH2 solution, stir, and react fully to obtain a polyethylene glycol compound modified with 3,4-dihydroxy mandelic acid; Dissolve acrylic acid in phosphate buffer, add EDC and NHS, and stir at room temperature to fully activate the carboxyl group of acrylic acid to form an acrylic acid carboxyl activation solution; Dissolve the polyethylene glycol compound modified with 3,4-dihydroxy mandelic acid in phosphate buffer, add the acrylic acid carboxyl activation solution thereto, stir and react fully to obtain monomer A; S2: Synthesis of monomer B: Dissolve polyethylene glycol diamine NH2-PEGn-NH2 in phosphate buffer, and dropwise add DOTA-NHS ester solution under stirring conditions, and stir and react fully to obtain a DOTA-PEG-NH2 solution; Dissolve acrylic acid in phosphate buffer, add EDC and NHS, and stir at room temperature to fully activate the carboxyl group of acrylic acid to form an acrylic acid carboxyl activation solution; Drop the acrylic acid carboxyl activation solution into the DOTA-PEG-NH2 solution, and stir and react fully to obtain monomer B; S3: Under a nitrogen atmosphere, dissolve monomer A, monomer B, and monomer C in isopropanol solution, heat and stir, raise the temperature, dissolve 2,2'-azobis(2-methylbutyronitrile) in isopropanol and add it to the reaction system, react for 4 hours, and subsequently supplement and add the initiator 2,2'-azobis(2-methylbutyronitrile), continue to react for 4 h, stop the reaction, dialyze and purify, and freeze-dry.

3. The comb copolymer dispersant according to claim 2, wherein: In step S1, the molar dosage ratio of 3,4-dihydroxy mandelic acid, polyethylene glycol diamine, and acrylic acid is (1-1.1):(1-1.05):(0.95-1).

4. The comb copolymer dispersant according to claim 2, wherein: In step S2, the molar dosage ratio of DOTA-NHS, polyethylene glycol diamine, and acrylic acid is (1-1.1):(1-1.05):(1-0.95).

5. The comb copolymer dispersant according to claim 2, wherein: In step S3, the molar dosage ratio of the monomer A, monomer B, and monomer C is (4-7):(3-5):(3-8).

6. A butter inhibitor comprising the comb copolymer dispersant according to any one of claims 1-5, characterized in that, By weight, it contains: 3-8 parts of polymerization inhibitor, 1-10 parts of antioxidant, 5-16 parts of comb-shaped copolymer dispersant, 3-5 parts of surfactant, and 50-80 parts of deionized water.

7. The butter inhibitor according to claim 6, characterized in that, The polymerization inhibitor is selected from at least one of propanolamine, isopropanolamine, and hydrazine hydrate.

8. The butter inhibitor according to claim 6, characterized in that, The antioxidant is selected from at least one of N,N-diethylhydroxylamine and sodium thiosulfate.

9. The butter inhibitor according to claim 6, wherein The surfactant is selected from at least one of sodium dodecylbenzenesulfonate and alkylphenol polyoxyethylene ether.

10. Use of the comb-shaped copolymer dispersant according to any one of claims 1-5 in the preparation of a butter inhibitor.

Images