Dispersing type anti-scaling agent for styrene device as well as preparation method and use method of dispersing type anti-scaling agent

Abstract

The invention discloses a dispersing type anti-scaling agent for a styrene device as well as a preparation method and a use method of the dispersing type anti-scaling agent. The dispersing type anti-scaling agent comprises the following raw material components in percentage by mass: 5-20% of an anti-coking component, 5-35% of an income increasing component, 5-35% of a dispersing component, 5-25% of a demulsification component and 35-60% of a solvent. The dispersing type anti-scaling agent in the scheme not only can effectively inhibit styrene polymerization, but also can improve the yield of styrene and reduce the generation amount of styrene tar in the rectification process; even if a part of styrene is subjected to polymerization reaction, the dispersing components in the anti-scaling agent can disperse the styrene into the material, and polymer scales adhered to the surface of equipment can be dispersed and cleaned; in addition, a demulsification component in the anti-scaling agent has a targeted adsorption and wrapping effect on polymers dispersed in the materials, and oil-water separation is accelerated; therefore, the operation cycle of the styrene device is prolonged; and the catalyst does not contain nitrogen and sulfur elements, so that the subsequent desulfurization and denitrification process of styrene tar is not influenced.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, and in particular to a dispersed anti-fouling agent for a styrene device and a preparation method and a use method thereof. Background Art

[0002] At present, most of the methods for producing styrene in the world adopt the ethylbenzene gas phase catalytic dehydrogenation process, that is, using ethylbenzene as the raw material, with the help of catalysts such as iron oxide-chromium or zinc oxide, using multi-stage adiabatic or tubular isothermal reactors, dehydrogenation to styrene in the presence of steam. The dehydrogenation product crude styrene after ethylbenzene dehydrogenation contains styrene, ethylbenzene and by-products benzene, toluene and a small amount of tar, etc., and further distillation is required to obtain high-purity styrene.

[0003] During the distillation process, styrene is very likely to undergo free radical polymerization under the initiation of metal ions, trace oxygen and heat, which not only leads to material loss of styrene, but the generated polymers will adhere to and accumulate on the distillation tower plates or packings, reboilers, material pipelines, etc., causing the tower pressure difference to increase and the reboiler to switch frequently, affecting the long-term operation of the device. Therefore, anti-scaling agents are needed to solve this problem.

[0004] So far, domestic and foreign researchers have proposed many methods to inhibit the polymerization of styrene. For example, the patent application with publication number US2013 / 0204053A1 proposes the use of hydroxybenzyl alcohol and a dehydration catalyst to add a styrene solution. After the hydroxybenzyl alcohol is dehydrated, a quinone styrene inhibitor is formed to inhibit the polymerization of styrene. The patent application with publication number US2016 / 0272586A1 studies a stable lipophilic hydroxylamine compound to slow down the polymerization of vinyl unsaturated compounds, which can reduce the amount of polymer generated at a certain concentration. The patent application with publication number CN103467230A has developed a water-soluble styrene inhibitor, which selects free radicals or their derivatives, amine substances, antioxidants, reducing agents and dispersing components as composite components, and is composed in a certain ratio. The synergistic effect between the components can be used to slow down the polymerization of styrene, and water is used as a solvent to reduce the use of organic solvents that are harmful to the environment and human body. The patent application with publication number CN104193576A uses a polymerization inhibitor compounded with quinone compounds and quinoline compounds, which can effectively extend the operation time of the styrene device, improve the output and quality of styrene products, and reduce the emission of tar from the styrene device. The patent application with publication number CN114751805A mixes free radical substituents, quinone compounds, ether compounds, metal deactivators, and dispersed components in a certain proportion and adds them to a solvent to obtain a green and environmentally friendly styrene polymerization inhibitor with good inhibition effect and long action time.

[0005] However, since styrene is very active and has a high polymerization activity, it is difficult to completely terminate its polymerization reaction. The inhibitors proposed in the published literature all slow down the polymerization of styrene to a certain extent by capturing styrene chain free radicals, but cannot completely terminate the polymerization, and the yield of styrene cannot be improved; moreover, although the polymer scale adhering to the surface of the equipment can be dispersed and cleaned, the polymer dispersed in the material is very easy to emulsify, which will still affect the long-term operation of the device. The raw materials used contain nitrogen and sulfur elements. During the combustion treatment of styrene tar, it is easy to cause excessive nitrogen oxides, which does not meet environmental protection requirements and affects the desulfurization and denitrification process. Most of the solvents used in the above inventions are easy to pollute the environment and have low inhibition efficiency, which is easy to cause waste of resources and secondary pollution.

[0006] Therefore, research on multifunctional environmentally friendly anti-scaling agents that do not contain nitrogen and sulfur elements has become a research hotspot in this industry. Summary of the invention

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a dispersed anti-scaling agent for a styrene device and a preparation method and a use method thereof. The dispersed anti-scaling agent can extend the operating cycle of the styrene device and the raw materials do not contain nitrogen and sulfur elements.

[0008] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0009] A dispersed anti-scaling agent for a styrene device comprises the following raw material components by mass percentage: anti-scorch component: yield-increasing component: dispersing component: demulsifying component: solvent = (5-20): (5-35): (5-35): (5-25): (35-60).

[0010] Preferably, the anti-scorch component is one of 3,6-di-tert-butyl-9,10-phenanthrenequinone, di(2-hydroxy-3,5-di-tert-butylphenyl)methane, 2,5-di-tert-butyl-1,4-benzoquinone, 2,6-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,4-benzoquinone and 4,4'-methylenebis(3,5-di-tert-butyl-2,6-dihydroxybenzoic acid).

[0011] Preferably, the yield-increasing component is selected from one of octaethylene glycol monododecyl ether, vanillin octanediol acetal polyoxyethylene ether and hydrogenated rosin alcohol polyoxyethylene ether.

[0012] Preferably, the dispersing component is selected from one of propylene glycol alginate, isopropyl myristate and sorbitan monopalmitate.

[0013] Preferably, the demulsifying component is selected from one of polyol block copolymers, epoxy resin alkoxy polymers and propylene glycol polyoxypropylene polyoxyethylene polyether.

[0014] Preferably, the solvent is selected from one of ethyl lactate, isoethylene glycol and dimethyl isosorbide.

[0015] A method for preparing the dispersed anti-fouling agent for a styrene device as described above comprises compounding an anti-scorch component, a yield increasing component, a dispersing component, a demulsifying component and a solvent in proportion, heating and stirring, fully dissolving, mixing evenly, and cooling to obtain the anti-fouling agent.

[0016] Preferably, the heating temperature is 40-60°C and the stirring time is 2-6h.

[0017] A method for using the above-mentioned dispersed anti-scaling agent for a styrene device, based on the crude styrene material flow rate, the added concentration of the anti-scaling dispersant is 100-1000ppm.

[0018] The dispersed anti-scaling agent for a styrene device provided by the present invention comprises an anti-coking component, a yield-increasing component, a dispersing component, a demulsifying component and a solvent, and its action mechanism is as follows: the anti-coking component has a coking and descaling effect, can significantly reduce the coking rate of a distillation tower tray, a reboiler, a material pipeline and the like in a styrene production process, and prevents the initiation of styrene polymerization by high temperature; the yield-increasing component can better stabilize the styrene component in the system during the distillation process, passivate or inhibit the polymerization reaction of the material at high temperature, thereby better extracting styrene, and achieving the purpose of improving the styrene yield; the dispersing component can disperse the generated polymer in the material, so that it is not easy to adhere to the surface of the equipment to block the tower, or remove the scale that has adhered to the surface of the equipment and flow away with the material; the demulsifying component has a targeted adsorption and wrapping effect on the polymer dispersed in the material, can effectively reduce the thickness and strength of the oil-water emulsion interface film, and accelerate the oil-water separation. In this way, by utilizing the synergistic effects of anti-scorch, dispersion, yield increase and demulsification, on the one hand, styrene polymerization is inhibited to a large extent and the yield of styrene is increased; on the other hand, even if some styrene is still polymerized, the polymer can be dispersed into the material through the dispersion effect, so that it is not easy to adhere and deposit on the surface of the equipment, and the demulsification component can inhibit the emulsification of the polymer dispersed in the material. Therefore, the dispersed anti-scaling agent for styrene device proposed by the present invention can inhibit the generation of scale in the styrene distillation system, increase the yield of styrene, meet production requirements, and extend the operation cycle of the device.

[0019] The anti-scaling agent of the present invention is easy to use. The anti-scaling agent can be added to the styrene distillation tower feed, reboiler or tower top reflux at a certain concentration. The added concentration of the anti-scaling agent is generally 100-1000ppm of the styrene distillation tower feed amount.

[0020] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0021] 1. The dispersed anti-scaling agent used in styrene units can not only effectively inhibit styrene polymerization, but also improve the yield of styrene and reduce the amount of styrene tar generated during the distillation process; even if some styrene undergoes polymerization, the dispersing components in the anti-scaling agent can disperse it into the material, making it less likely to adhere to the surface of the equipment and avoid clogging the tower. At the same time, the polymer scale adhering to the surface of the equipment can also be dispersed and cleaned; in addition, the demulsifying component in the anti-scaling agent has a targeted adsorption and wrapping effect on the polymer dispersed in the material, which can effectively reduce the thickness and strength of the oil-water emulsion interface film and accelerate oil-water separation; and it can disperse the scale adhering to the surface of the equipment without emulsifying the material, thereby extending the operation cycle of the styrene unit;

[0022] 2. The components of the anti-scaling agent used do not contain nitrogen and sulfur elements, and do not affect the subsequent desulfurization and denitrification process of styrene tar; the solvent used is an environmentally friendly organic solvent, which reduces the harm to the environment and human body. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below, which is intended to be used to explain the present invention but should not be construed as limiting the present invention. The protection scope of the present invention is not limited thereto.

[0024] Example 1

[0025] Add 100g of 3,6-di-tert-butyl-9,10-phenanthrenequinone, 150g of vanillin octanediol acetal polyoxyethylene ether, 150g of isopropyl myristate, 150g of epoxy resin alkoxy polymer and 450g of dimethyl isosorbide into a container, heat and stir at 50°C for 3h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0026] Example 2

[0027] Add 200g of di(2-hydroxy-3,5-di-tert-butylphenyl)methane, 100g of octaethylene glycol monododecyl ether, 150g of propylene glycol alginate, 100g of polyol block copolymer and 450g of isoethylene glycol into a container, heat and stir at 40°C for 2h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0028] Example 3

[0029] Add 100g of 4,4'-methylenebis(3,5-di-tert-butyl-2,6-dihydroxybenzoic acid), 150g of hydrogenated rosin alcohol polyoxyethylene ether, 100g of sorbitan monopalmitate, 50g of polyol block copolymer and 600g of isoethylene glycol into a container, heat and stir at 40°C for 3h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0030] Example 4

[0031] Add 150g of 2,6-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,4-benzoquinone, 250g of octaethylene glycol monododecyl ether, 50g of isopropyl tetradecanoate, 50g of propylene glycol polyoxypropylene polyoxyethylene polyether and 500g of ethyl lactate into a container, heat and stir at 60°C for 5h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0032] Example 5

[0033] Add 80g of 2,5-di-tert-butyl-1,4-benzoquinone, 100g of hydrogenated rosin alcohol polyoxyethylene ether, 350g of propylene glycol alginate, 70g of polyol block copolymer and 400g of isoethylene glycol into a container, heat and stir at 50°C for 5h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0034] Example 6

[0035] Add 100g of 3,6-di-tert-butyl-9,10-phenanthrenequinone, 150g of hydrogenated rosin alcohol polyoxyethylene ether, 200g of sorbitan monopalmitate, 100g of propylene glycol polyoxypropylene polyoxyethylene polyether and 450g of isoethylene glycol into a container, heat and stir at 50°C for 4h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0036] Example 7

[0037] 80g of 4,4'-methylenebis(3,5-di-tert-butyl-2,6-dihydroxybenzoic acid), 200g of octaethylene glycol monododecyl ether, 220g of isopropyl tetradecanoate, 100g of polyol block copolymer and 400g of dimethyl isosorbide were added to a container, heated and stirred at 40°C for 2h, fully dissolved and mixed, cooled to room temperature, filtered to obtain an anti-scaling agent. The anti-scaling performance was evaluated.

[0038] Example 8

[0039] Add 100g of di(2-hydroxy-3,5-di-tert-butylphenyl)methane, 50g of octaethylene glycol monododecyl ether, 100g of isopropyl tetradecanoate, 400g of propylene glycol polyoxypropylene polyoxyethylene polyether and 350g of isoethylene glycol into a container, heat and stir at 50°C for 3h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0040] Example 9

[0041] Add 50g of di(2-hydroxy-3,5-di-tert-butylphenyl)methane, 200g of octaethylene glycol monododecyl ether, 100g of isopropyl tetradecanoate, 150g of polyol block copolymer and 500g of ethyl lactate into a container, heat and stir at 60°C for 4h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0042] Example 10

[0043] Add 80g of 2,6-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,4-benzoquinone, 200g of hydrogenated rosin alcohol polyoxyethylene ether, 100g of sorbitan monopalmitate, 170g of propylene glycol polyoxypropylene polyoxyethylene polyether and 450g of isoethylene glycol into a container, heat and stir at 40°C for 5h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0044] Comparative Example 1

[0045] Add 380g of octaethylene glycol monododecyl ether, 220g of polyol block copolymer and 400g of isosorbide dimethyl ether into a container, heat and stir at 40°C for 4h, fully dissolve and mix, cool to room temperature, and filter to obtain the anti-scaling agent.

[0046] Comparative Example 2

[0047] The commercially available styrene antifouling agent DNBP was used.

[0048] The anti-scaling performance of the anti-scaling agent was evaluated using a simulation device.

[0049] Evaluation of anti-scaling performance: A certain amount of stainless steel filler is loaded into a self-made stainless steel simulation tower, and the filler layer is fixed. The anti-scaling agent and crude styrene material are mixed evenly and added to the tower bottom. Vacuum distillation is carried out at 120-125℃, and the vacuum degree is -70~-100kPa. The styrene extracted from the top of the tower is refluxed to the feed port in the middle of the distillation tower. As the evaluation time increases, scale is continuously deposited on the surface of the filler to form a scale layer. After 72 hours of testing, the styrene tar content in the tower bottom liquid is measured, and the total weight W of scale on the filler surface is calculated and compared with the total weight W0 of scale when no anti-scaling agent is added, and the anti-scaling rate is calculated.

[0050] Anti-scaling rate expression:

[0051] The anti-scaling effect of the anti-scaling agent can be expressed by the anti-scaling rate η:

[0052] Anti-scaling rate

[0053] Wherein, W0 is the total weight of scale without adding anti-scaling agent, and W is the total weight of scale after adding anti-scaling agent.

[0054] The anti-scaling performance evaluation method was used to evaluate the anti-scaling performance of the anti-scaling agents of Examples 1-10 and Comparative Examples 1 and 2. The anti-scaling performance evaluation experimental data of Examples 1-10 and Comparative Examples 1 and 2 are shown in Table 1.

[0055] Table 1: Anti-scaling performance test results of the anti-scaling agents provided in Examples 1-10 and Comparative Examples 1 and 2

[0056]

[0057]

[0058] As can be seen from Table 1, the anti-scaling agent provided by Examples 1 to 10 has a good anti-scaling effect, can effectively inhibit the formation of styrene scale, and the anti-scaling effect is positively correlated with the amount added within a certain range. It can be seen from Examples 1 to 10 and Comparative Example 1 that the anti-scorch component, the dispersing component, the yield-increasing component and the demulsifying component play a synergistic role, wherein the absence of one or more components greatly reduces the anti-scaling performance of styrene, and the content of styrene tar in the tower bottom liquid is also significantly increased. By comparing Example 7 with Comparative Example 2, it can be seen that under the condition of the same injection concentration, the anti-scaling agent prepared in Example 7 has a significantly better ability to inhibit the polymerization of styrene than the currently commercially available styrene inhibitor; it can be seen from Examples 2, 5, 6, 7, 10 and Comparative Example 2 that the content of styrene coal tar in the tower bottom liquid after the reaction of 2, 5, 6, and 7 is lower than that of the currently commercially available styrene inhibitor, which indicates that the anti-scaling agent can reduce the production of styrene coal tar and improve the yield of styrene. The anti-fouling agent of the present invention does not contain N and S elements, and while ensuring excellent polymerization inhibition performance on styrene, it is more green and environmentally friendly, and conforms to the green environmental protection concept advocated today.

[0059] All features described in the description and the appended claims are essential features of the invention both individually and in any combination.

[0060] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Ordinary technicians in the field can change, modify, replace, modify, delete some features, add features or re-combine features to form a technical solution in the above embodiments without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the innovative principles of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A dispersed anti-fouling agent for a styrene device, characterized in that: The raw material components include the following by mass percentage: anti-coking component: yield-increasing component: dispersing component: demulsifying component: solvent = (5-20): (5-35): (5-35): (5-25): (35-60).

2. A dispersed anti-fouling agent for a styrene device according to claim 1, characterized in that: The anti-scorch component is one of 3,6-di-tert-butyl-9,10-phenanthrenequinone, di(2-hydroxy-3,5-di-tert-butylphenyl)methane, 2,5-di-tert-butyl-1,4-benzoquinone, 2,6-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,4-benzoquinone and 4,4'-methylenebis(3,5-di-tert-butyl-2,6-dihydroxybenzoic acid).

3. A dispersed anti-fouling agent for a styrene device according to claim 1, characterized in that: The yield-increasing component is selected from one of octaethylene glycol monododecyl ether, vanillin octanediol acetal polyoxyethylene ether and hydrogenated rosin alcohol polyoxyethylene ether.

4. The dispersed anti-fouling agent for a styrene device according to claim 1, characterized in that: The dispersing component is selected from one of propylene glycol alginate, isopropyl myristate and sorbitan monopalmitate.

5. The dispersed anti-fouling agent for a styrene device according to claim 1, characterized in that: The demulsifying component is selected from one of a polyol block copolymer, an epoxy resin alkoxy polymer and a propylene glycol polyoxypropylene polyoxyethylene polyether.

6. The dispersed anti-fouling agent for styrene equipment according to claim 1, characterized in that: The solvent is selected from one of ethyl lactate, isoethylene glycol and dimethyl isosorbide.

7. A method for preparing a dispersed anti-fouling agent for a styrene device as claimed in any one of claims 1 to 6, characterized in that: The anti-scorch component, the yield-increasing component, the dispersing component, the demulsifying component and the solvent are compounded in proportion, heated and stirred, fully dissolved, mixed evenly, and cooled to obtain the product.

8. The dispersed anti-fouling agent for styrene equipment according to claim 7, characterized in that: The heating temperature is 40-60°C and the stirring time is 2-6h.

9. A method for using a dispersed anti-fouling agent for a styrene device as claimed in any one of claims 1 to 6, characterized in that: Based on the crude styrene material flow rate, the added concentration of the anti-fouling dispersant is 100-1000ppm.

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