阅读说明：本技术 一种煤焦油加氢阻垢剂及其制备方法 (Coal tar hydrogenation scale inhibitor and preparation method thereof ) 是由 付鑫 林向阳 程文武 李有金 杨闯 孔凡龙 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种煤焦油加氢阻垢剂及其制备方法,所述阻垢剂成分按重量百分比包括：含芳胺基的梳形聚合物分散剂20～34%,缓蚀分散剂15～26%,自由基型阻聚剂5～8%,抗氧剂10～15%,溶剂20～50%；本发明阻垢剂可用于抑制煤焦油加氢装置预热换热器、加热炉管、管线等高温设备的结垢并清除已经形成的垢物,同时改善酚类物质对设备、管线的腐蚀问题。本发明阻垢剂添加的含芳胺基的梳形聚合物分散剂高温稳定性好,分子中拥有多个芳胺基和长链烷基基团,大大增强了分散剂与垢物的结合力,对垢物具有更好的清除分散作用。(The invention discloses a coal tar hydrogenation scale inhibitor and a preparation method thereof, wherein the scale inhibitor comprises the following components in percentage by weight: 20-34% of arylamine-containing comb-shaped polymer dispersant, 15-26% of corrosion inhibition dispersant, 5-8% of free radical type polymerization inhibitor, 10-15% of antioxidant and 20-50% of solvent; the scale inhibitor can be used for inhibiting the scaling of high-temperature equipment such as a preheating heat exchanger, a heating furnace tube, a pipeline and the like of a coal tar hydrogenation device, removing scale substances formed, and simultaneously improving the corrosion problem of phenolic substances to the equipment and the pipeline. The comb-shaped polymer dispersant containing arylamine groups added in the scale inhibitor has good high-temperature stability, and the molecules of the comb-shaped polymer dispersant contain a plurality of arylamine groups and long-chain alkyl groups, so that the binding force of the dispersant and the scale is greatly enhanced, and the comb-shaped polymer dispersant has better cleaning and dispersing effects on the scale.)

1. The coal tar hydrogenation scale inhibitor is characterized by comprising the following components in percentage by weight: 20-34% of arylamine-containing comb-shaped polymer dispersant, 15-26% of corrosion inhibition dispersant, 5-8% of free radical type polymerization inhibitor, 10-15% of antioxidant and 20-50% of solvent.

2. The coal tar hydrogenation scale inhibitor according to claim 1, characterized in that: the preparation method of the comb-shaped polymer dispersant containing arylamine groups comprises the following steps:

mixing arylamine, sodium bicarbonate and solvent, heating and stirring, slowly adding 4-vinyl benzyl chloride to react to obtain N-4-vinyl benzyl arylamine, dissolving N-4-vinyl benzyl arylamine and α olefin of C8-C20 in toluene, adding catalyst under the protection of nitrogen gas to make copolymerization so as to obtain the comb-shaped polymer dispersing agent containing correspondent arylamine group.

3. The coal tar hydrogenation scale inhibitor according to claim 2, wherein the arylamine group-containing comb polymer dispersant has the following structural formula:

wherein R is one of phenyl, naphthyl, p-hydroxyphenyl and quinolyl; p is 1 to 13, m is 2 to 80, and n is 2 to 80.

4. The coal tar hydrogenation scale inhibitor according to claim 1, characterized in that: the corrosion inhibition dispersing agent adopts alkyl imidazoline quaternary ammonium salt surfactant TA 80.

5. The coal tar hydrogenation scale inhibitor according to claim 1, characterized in that: the free radical polymerization inhibitor adopts phosphorous acid tris (4-hydroxy-2, 2,6, 6-tetramethyl piperidine nitroxide free radical) ester and sebacic acid bis (4-hydroxy-2, 2,6, 6-tetramethyl piperidine nitroxide free radical) ester.

6. The coal tar hydrogenation scale inhibitor according to claim 1, wherein the antioxidant is at least one selected from 2,2 '-methylenebis (4-methyl-6-tert-butylphenol), 2, 6-di-tert-butyl-4-methoxyphenol, tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxy) phenylpropionic acid ] pentaerythritol ester, β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester, N-di-sec-butyl-p-phenylenediamine, N-isopropyl-N' -phenyl-p-phenylenediamine, N '-phenyl-p-phenylenediamine, N-cyclohexyl-N-phenyl-p-phenylenediamine, N-sec-octyl-N' -phenyl-p-phenylenediamine and N- (4-tert-octylphenyl) -1-naphthylamine.

7. The coal tar hydrogenation scale inhibitor according to claim 1, characterized in that: the solvent adopts kerosene, diesel oil or heavy aromatics.

8. The preparation method of the coal tar hydrogenation scale inhibitor as claimed in any one of claims 1 to 7, characterized by comprising the following steps: weighing the components in proportion, heating and stirring at 50-70 ℃ for 3-5 hours, and cooling to room temperature.

9. The coal tar hydrogenation scale inhibitor as claimed in any one of claims 1 to 7 is used for inhibiting the generation of new scales on a coal tar hydrogenation device and/or removing scales attached to the surface of the device.

10. The use of claim 9, which comprises injecting the anti-scalant directly into the pipeline or feed pump pre-oil ahead of the fouling site by means of a metering pump; preferably, the addition concentration of the coal tar hydrogenation scale inhibitor is 10-200 mug/g; more preferably, the concentration of the additive is 30 to 120 [ mu ] g/g.

Technical Field

The invention belongs to the technical field of coal chemical industry, and particularly relates to a scale inhibitor suitable for high-temperature equipment of a coal tar hydrogenation device.

Background

Chinese energy is characterized by more coal, less oil and less gas. With the rapid development of domestic industry, the demand for petroleum is continuously increasing, and the import amount of petroleum is gradually increased year by year. In 2014, the external dependence of China oil is 60% breakthrough, the external dependence of China oil is expected to reach 68% in 2020, and the search for a new way for preparing fuel oil is of great importance.

Coal tar is a liquid byproduct generated in coal chemical production processes such as coal coking, semi coke production, coal gas production, lignite pyrolysis and the like, has a very complex composition, and mainly comprises aromatic hydrocarbon, aliphatic hydrocarbon, naphthenic hydrocarbon, heterocyclic compounds and the like. At present, the coal tar yield of China breaks through 2000 kiloton/a. However, coal tar has not been effectively utilized for a long time, and most of the coal tar is roughly combusted as low-end fuel oil.

Coal tar hydrogenation technology originated in germany in the 30's of the 20 th century. This technology was not currently put to industrial use due to the high reaction pressure requirements. Later, the research of this technology was forced to stop due to the extensive discovery and exploitation of oil. After the 21 st century, the development of coal hydrogenation technology in China has been promoted by the rapid development of coal chemical industry. The coal tar hydrogenation technology is characterized in that under the action of high temperature, high pressure and a catalyst, a large amount of unsaturated hydrocarbons, aromatic hydrocarbons, colloid and asphaltene in the coal tar are saturated through hydrofining and hydrocracking to obtain saturated hydrocarbons with low molecular weight, and meanwhile, heteroatom and metal impurities such as S, N, O and the like are removed through hydrogenation to improve the stability of the saturated hydrocarbons, so that naphtha fraction and fuel oil fraction are obtained to become light petroleum product raw materials. The coal tar hydrogenation technology has made significant progress in China over the past 20 years. Since 2010, domestic coal tar hydrogenation projects are accelerated to the ground, and by 2017, the capacity of the built coal tar hydrogenation device reaches 700 ten thousand t/a, and more than 30 coal tar hydrogenation projects are built. Under the current requirements of building an environment-friendly society and sustainable development in China, the application of the coal tar hydrogenation technology has the advantages of high environmental protection, low cost, stable quality and the like, so that the coal tar hydrogenation process is a direction for the vigorous development of the oil refining industry in the future.

In a coal tar hydrogenation device, before entering a hydrogenation reactor, coal tar needs to be heated to a proper reaction temperature through heat exchange of a heat exchanger and temperature rise of a heating furnace. In actual industrial production, after the coal tar is heated to more than 200 ℃, the coal tar is easy to coke and deposit on the surfaces of the heat exchanger, the heating furnace tube, the pipeline and other equipment which flow through the coal tar, so that the heat transfer effect of the heat exchanger and the heating furnace is poor, the energy consumption is increased, the treatment capacity of the device is reduced, even the pipeline is blocked, the shutdown and scale removal are forced, the operation cost is increased, the start-up period is shortened, and the economic benefit is reduced. At present, the scaling problem of high-temperature equipment such as a heat exchanger, a heating furnace and the like becomes an important factor for restricting the long-term stable operation of a coal tar hydrogenation device.

There are generally two methods to solve the problem of equipment fouling. One method is to improve equipment and process flow, such as adding pretreatment equipment for desalting, dewatering and the like, installing a filter, cutting heavy distillate oil, improving the flow rate of oil and the like, and has certain effects, but the method has limitations and only can play a role in delaying the scaling speed. The other method is a chemical method, which is to add a trace amount of scale inhibitor into oil to inhibit the generation of coke scale and simultaneously remove the coke scale which is deposited on the surface of equipment. The method has the advantages of no change of process flow, no need of stopping, convenient and flexible use, low capital investment and the like, and is widely applied to the oil refining industry at present. However, the coal tar hydrogenation technology is developed later, and compared with petroleum heavy distillate, the coal tar has the characteristics of high content of colloid and asphaltene, high content of heteroatoms, high content of solid impurities and the like, so that the problems of coking and scale deposition are more likely to occur. At present, no scale inhibitor specially aiming at a coal tar hydrogenation device appears. Therefore, the invention of the scale inhibitor which can be suitable for the coal tar hydrogenation device is very important.

Disclosure of Invention

The invention aims to solve the problem of coking and scale deposition of high-temperature equipment such as a preheating heat exchanger, a heating furnace tube, a pipeline and the like of a coal tar hydrogenation device, and provides a coal tar hydrogenation scale inhibitor which is small in dosage, green and environment-friendly and excellent in scale inhibition and scale removal performance and a preparation method thereof; the scale inhibitor can inhibit the generation of new scales, and can simultaneously remove the scales attached to the surface of equipment on line, thereby providing necessary conditions for energy conservation, consumption reduction and long-period operation of a coal tar hydrogenation device.

In order to achieve the purpose, the invention provides a coal tar hydrogenation scale inhibitor, which comprises the following components in percentage by weight: 20-34% of arylamine-containing comb-shaped polymer dispersant, 15-26% of corrosion inhibition dispersant, 5-8% of free radical type polymerization inhibitor, 10-15% of antioxidant and 20-50% of solvent.

In an embodiment of the present invention, the present invention provides an arylamine group-containing comb polymer dispersant prepared by the following method: mixing arylamine, sodium bicarbonate and a solvent, heating and stirring, and slowly adding 4-vinylbenzyl chloride for reaction to obtain N-4-vinylbenzyl arylamine; then N-4-vinyl benzyl arylamine and C₈～C₂₀α olefin is dissolved in toluene, and a catalyst is added for copolymerization under the protection of nitrogen to obtain the comb-shaped polymer dispersant containing corresponding arylamine groups, wherein in some embodiments of the invention, the arylamine is selected from one of aniline, 1-aminonaphthalene, 4-aminophenol and 4-aminoquinoline, and in other embodiments of the invention, the solvent is selected from one of water, ethanol and isopropanol tetrahydrofuran.

In some preferred embodiments of the present invention, the arylamine group-containing comb polymer dispersant has the following structural formula:

wherein R is one of phenyl, naphthyl, p-hydroxyphenyl and quinolyl; p is 1-13, m is 2-80, and n is 2-80;

in some embodiments of the invention, R is naphthyl; p is 11.

In some embodiments of the invention, the corrosion inhibiting dispersant employs alkyl imidazoline quaternary surfactant TA 80.

In some embodiments of the present invention, the radical polymerization inhibitor is one of tris (4-hydroxy-2, 2,6, 6-tetramethylpiperidinyloxy) phosphite and bis (4-hydroxy-2, 2,6, 6-tetramethylpiperidinyloxy) sebacate. Preferably, the free radical polymerization inhibitor is tris (4-hydroxy-2, 2,6, 6-tetramethylpiperidinyloxy) phosphite.

In some embodiments of the present invention, the antioxidant is at least one of 2,2 '-methylenebis (4-methyl-6-tert-butylphenol), 2, 6-di-tert-butyl-4-methoxyphenol, tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxy) benzenepropanoic acid ] pentaerythritol, β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propanoic acid octadecyl ester, N-di-sec-butyl-p-phenylenediamine, N-isopropyl-N' -phenyl-p-phenylenediamine, N '-phenyl-p-phenylenediamine, N-cyclohexyl-N-phenyl-p-phenylenediamine, N-sec-octyl-N' -phenyl-p-phenylenediamine, and N- (4-tert-octylphenyl) -1-naphthylamine.

In some embodiments of the present invention, the solvent is one of kerosene, diesel oil, and heavy aromatics.

The content of colloid and asphaltene in the coal tar is up to more than 40 percent, and the polycyclic aromatic hydrocarbon, the colloid and the like are easy to dehydrogenate and condense into the asphaltene at high temperature, so that the asphaltene content is further increased; the aromatic condensed ring planar structure of asphaltene molecules in coal tar is easy to mutually stack together through pi-pi conjugation; the coal tar also contains about 10 percent of O, about 1 percent of N and about 0.5 percent of S, and the polar heteroatom groups enhance the associativity among the asphaltenes through the action of hydrogen bonds, so that the size of asphaltene aggregates is increased, and the asphaltene aggregates are finally separated out and deposited on the surface of equipment to become scales; secondly, the coal tar contains more solid particles, mainly coal dust brought by coal gas from a coking chamber of the coke oven, and a plurality of metal mineral substances, wherein the solid particles are dispersed in the coal tar and can be used as 'seed crystals' to adsorb asphaltene in the coal tar and grow gradually, and the small particles can be deposited after growing to a certain degree, so that the deposition of the asphaltene on the metal surface is accelerated; the coal tar also contains a small amount of olefin and diene, and is easy to polymerize into a high-molecular olefin polymer at high temperature; after being deposited on the metal surface, the asphaltene and the olefin polymer are further dehydrogenated and condensed under the action of high temperature, the condensation degree is increased and the adhesion is enhanced along with the prolonging of time, and finally coke scale is formed; in addition, the coal tar contains a large amount of acidic substances such as phenols, and the surface of the stainless steel is corroded at high temperature, so that the surface of the stainless steel becomes rough, and dirt is more easily attached.

The arylamine group-containing comb-shaped polymer dispersant in the scale inhibitor has excellent high-temperature stability, is not easy to decompose, and can adapt to high-temperature environments in heat exchangers and heating furnace pipes; benzene ring structures in the molecules of the dispersing agent can be adsorbed or embedded between lamellar molecules of the dirt through pi-pi conjugation, amino groups can easily generate hydrogen bond action with heteroatoms in the dirt, the adsorption action of the dispersing agent on the surface of the dirt is enhanced, and long-chain alkyl groups can easily extend into a liquid-phase medium; in addition, the comb-shaped polymer structure enables the molecules of the dispersing agent to have a plurality of arylamine groups and long-chain alkyl groups, so that the adsorption force of the dispersing agent on the surface of dirt is greatly enhanced, the dispersing agent is not easy to fall off, and meanwhile, the binding force of the long-chain alkyl groups and a liquid phase medium is enhanced; when the binding force of the dispersing agent to the dirt and the liquid-phase medium is larger than the adsorption force of the surface of the equipment to the dirt or the dirt and the dirt, the dirt is peeled off and is dissolved in the liquid-phase medium in a micelle form. For the scale precursors which are precipitated but not deposited on the surface of the equipment, the dispersing agent can form micelles with the scale precursors, and the micelles can be dispersed in a liquid phase medium, so that the scale precursors are not easy to deposit on the surface of the equipment.

The corrosion inhibition dispersant alkyl imidazoline quaternary ammonium salt surfactant TA80 can be adsorbed on the surface of metal equipment to form a protective layer, so that corrosion of acidic substances such as phenols to the surface of stainless steel at high temperature is inhibited; meanwhile, TA80 can effectively disperse the coal dust particles carried in the coal tar; the data show that the surface of the coal dust is negatively charged, quaternary ammonium cation groups in TA80 can be adsorbed on the surface of the coal dust through electrostatic attraction, and alkyl groups in TA80 extend into a liquid phase, so that the coal dust is dispersed and shielded; on one hand, the deposition of the coal dust is inhibited, and on the other hand, the coal dust is prevented from adsorbing asphaltene in the coal tar.

The free radical polymerization inhibitor is an efficient chain terminator and can inhibit polymerization and scaling of olefin and diene in coal tar.

The antioxidant can eliminate peroxy radicals in the coal tar, thereby inhibiting free radical polymerization reaction initiated by the peroxy radicals.

The effective components of the coal tar hydrogenation scale inhibitor provided by the invention have excellent stability at a high temperature of 250-480 ℃ in equipment such as a heating furnace tube, a heat exchanger and a pipeline, are not easy to decompose, and can be ensured to play respective functions stably. The coal tar hydrogenation scale inhibitor provided by the invention can effectively remove the dirt deposited on the surface of equipment; the dispersion and solubilization effects on existing solid particles and asphaltene aggregates in coal tar can prevent the existing solid particles and asphaltene aggregates from depositing on the surface of equipment; the catalyst has the functions of eliminating peroxy radicals and terminating free radical chain reaction, and effectively inhibits olefin and diene from polymerizing into macromolecular organic matters; has corrosion inhibiting function and can inhibit the corrosion of phenol and other acidic substances on the surface of stainless steel. The purposes of inhibiting and removing the scale are finally achieved through the synergistic effect of the components.

The invention provides a preparation method of a coal tar hydrogenation scale inhibitor, which comprises the steps of weighing the components in proportion, heating and stirring at 50-70 ℃ for 3-5 hours, and cooling to room temperature. The preparation method is simple and convenient, and is green and environment-friendly.

The invention also provides a use method of the coal tar hydrogenation scale inhibitor; the scale inhibitor can be directly injected into a pipeline in front of a scaling part or a front oil material of a feeding pump through a metering pump; the addition concentration of the scale inhibitor in the coal tar is 10-200 mu g/g, preferably 30-120 mu g/g.

Detailed Description

The present invention is described in detail below with reference to examples, which should not be construed as limiting the scope of the present invention.

The arylamine group-containing comb polymer dispersants used in the following examples were obtained by the following preparation method:

mixing and stirring 1-aminonaphthalene, sodium bicarbonate and ethanol, heating to 60-90 ℃, slowly adding 4-vinylbenzyl chloride, and continuously reacting at 60-90 ℃ for 3-5 hours; cooling, filtering, separating filtrate, washing organic layer with saturated saline solution, and drying with anhydrous sodium sulfate; then distilling under reduced pressure to remove unreacted raw materials to obtain N-4-vinyl benzyl naphthylamine; dissolving N-4-vinyl benzyl naphthylamine and 1-hexadecene in toluene, adding a supported titanium catalyst under the protection of nitrogen for copolymerization, and precipitating, washing and drying the copolymerization product by ethanol to obtain the comb-shaped polymer dispersant containing the corresponding arylamine group.

The preparation method of the coal tar hydrogenation scale inhibitor comprises the following steps: