A method and system for separating the product of anthracene alkylation

Abstract

The present invention relates to the technical field of alkyl anthracene production, and particularly relates to a method and a system for separating anthracene alkylation reaction products. The method includes: (1) introducing a liquid material containing anthracene alkylation reaction products into a first distillation column for vacuum distillation I; (2) introducing the first bottom product into an alkyl anthracene tank for gas-liquid separation to obtain a first gas phase and a first liquid phase; introducing the first liquid phase into a second distillation column for vacuum distillation II; (3) introducing the second top product into a condenser for condensation treatment to respectively obtain a second gas phase and a second liquid phase, refluxing a part of the second liquid phase to the second distillation column, and introducing the remaining part of the second liquid phase into a monoalkyl anthracene tank for gas-liquid separation to obtain a third gas phase and a monoalkyl anthracene product. The method provided by the present invention can prevent the distillation pipeline from being blocked by easily condensable substances while realizing the efficient separation of anthracene alkylation reaction products.

Description

Technical Field

[0001] The present invention relates to the technical field of alkyl anthracene production, and particularly relates to a method and a system for separating anthracene alkylation reaction products. Background Art

[0002] Hydrogen peroxide is an important green basic chemical with a very wide range of industrial applications. China has been the world's largest producer of hydrogen peroxide for many consecutive years. In 2020, the domestic production capacity was approximately 19 million tons (calculated as hydrogen peroxide solution with a mass fraction of hydrogen peroxide of 27.5%).

[0003] Currently, the main process technologies for producing hydrogen peroxide at home and abroad are the anthraquinone method. 2-Alkyl anthraquinone in this process, as the "carrier" of the process, directly affects the quality and output of hydrogen peroxide.

[0004] The process route for preparing 2-alkyl anthraquinone by oxidizing 2-alkyl anthracene is considered a green production process technology with broad application prospects due to its advantages such as simple process flow, wide raw material sources, and low environmental pollution.

[0005] Among them, the key raw material 2-alkyl anthracene can be prepared by anthracene alkylation reaction technology. Under the action of acid catalysis, anthracene can undergo an alkylation reaction with an alkylating agent. After the reaction product system is treated by a special separation technology, the target product 2-alkyl anthracene can be obtained. Then, by using a specific oxidation technology, the purpose of efficiently preparing 2-alkyl anthraquinone from 2-alkyl anthracene can be achieved.

[0006] US4255343A, CN107602368A, CN107670686A, and Armengol E in the paper have all disclosed the alkylation method of anthracene, but none of them have given a method for separating 2-alkyl anthracene from the anthracene alkylation reaction products.

[0007] In-depth analysis of the anthracene alkylation reaction system shows that both the raw material anthracene and the product alkyl anthracene are polycyclic aromatic hydrocarbons with high boiling points and high melting points. Limited by catalytic activity and selectivity, the anthracene alkylation products are mostly mixtures. Therefore, in order to obtain 2-alkyl anthracene, it is necessary to develop an efficient separation technology for the anthracene - multiple alkyl anthracene mixture system to provide intermediate raw materials for the preparation of 2-alkyl anthraquinone.

[0008] According to the difference in the boiling points of the components of the alkylation products, the anthracene alkylation mixture can be separated by vacuum distillation. The difficulty lies in that the melting point of anthracene reaches 215°C. Once there is a problem with the pipeline insulation, it is extremely easy to cause blockage, seriously affecting the continuous and stable operation of the process. In addition, anthracene is extremely easy to sublime, and the sublimation temperature is difficult to control, significantly increasing the chance of pipeline blockage. If the problem of pipeline blockage can be solved, vacuum distillation is still the most promising separation method for industrial applications.

[0009] Both CN109704910A and CN111825510A have disclosed a separation method for a mixture containing an anthracene alkylation reaction product. The separation steps include: alkylation solvent separation, melt crystallization, and multi-stage vacuum distillation. Although this method can achieve a good separation effect, the process is too complex, the operation difficulty is large, and the energy consumption of crystallization and vacuum distillation is high, resulting in a high industrial application cost. Summary of the Invention

[0010] The object of the present invention is to overcome the defects of easy blockage of pipelines and low separation efficiency existing in the existing alkyl anthracene separation technology.

[0011] To achieve the above object, the first aspect of the present invention provides a method for separating an anthracene alkylation reaction product, the method comprising:

[0012] (1) In the presence of a solvent, introducing a feed liquid containing an anthracene alkylation reaction product into a first distillation column for vacuum distillation I to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds, controlling the conditions of the vacuum distillation I such that the content of the alkyl anthracene component in the first distillate is not greater than 1.0 wt% and the content of the alkyl anthracene component in the first bottom product is not less than 99.0 wt%, and the alkyl anthracene component includes monoalkyl anthracene and alkyl anthracene heavy components;

[0013] (2) Introducing the first bottom product into an alkyl anthracene tank for gas-liquid separation to obtain a first gas phase and a first liquid phase; introducing the first gas phase into a first baffle tank for condensation treatment, and introducing the first liquid phase into a second distillation column for vacuum distillation II to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene, controlling the conditions of the vacuum distillation II such that the content of monoalkyl anthracene in the second top product is not less than 99.0 wt%;

[0014] (3) Introducing the second top product into a condenser for condensation treatment to respectively obtain a second gas phase and a second liquid phase, refluxing a part of the second liquid phase to the second distillation column, and introducing the remaining part of the second liquid phase into a monoalkyl anthracene tank for gas-liquid separation to obtain a third gas phase and a monoalkyl anthracene product; and

[0015] Introducing the second gas phase into a second baffle tank for condensation treatment;

[0016] Introducing the third gas phase into a third baffle tank for condensation treatment;

[0017] Introducing the second bottom product into an alkyl anthracene heavy component tank for gas-liquid separation to obtain a fourth gas phase and an alkyl anthracene heavy component product; introducing the fourth gas phase into a fourth baffle tank for condensation treatment;

[0018] Among them, the structures of the first baffle tank, the second baffle tank, the third baffle tank, and the fourth baffle tank are the same or different, and each independently includes:

[0019] A tank body, which is provided with a fluid separation chamber; and

[0020] A vertical baffle, which is arranged in the fluid separation chamber for separating fluids;

[0021] Among them, a fluid inlet pipe section extending from the circumferential side of the fluid separation chamber, a fluid outlet pipe section extending from the top of the fluid separation chamber, and a discharge port pipe section extending from the lowest point of the fluid separation chamber are provided on the tank wall of the tank body.

[0022] The second aspect of the present invention provides a system for separating anthracene alkylation reaction products, and the system includes:

[0023] A first distillation column, which is used to carry out vacuum distillation I of a liquid material containing anthracene alkylation reaction products therein to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds;

[0024] A second distillation column, which is in fluid communication with the alkyl anthracene tank and is used to carry out vacuum distillation II of a first liquid phase from the alkyl anthracene tank therein to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene;

[0025] A baffle tank, which includes a first baffle tank in fluid communication with the alkyl anthracene tank, a second baffle tank in fluid communication with the condenser, a third baffle tank in fluid communication with the monoalkyl anthracene tank, and a fourth baffle tank in fluid communication with the alkyl anthracene heavy component tank; the first baffle tank is used to carry out condensation treatment of a first gas phase from the alkyl anthracene tank therein, the second baffle tank is used to carry out condensation treatment of a second gas phase from the condenser therein, the third baffle tank is used to carry out condensation treatment of a third gas phase from the monoalkyl anthracene tank therein, and the fourth baffle tank is used to carry out condensation treatment of a fourth gas phase from the alkyl anthracene heavy component tank therein;

[0026] A product tank, which includes an alkyl anthracene tank arranged on a pipeline between the first distillation column and the second distillation column, a monoalkyl anthracene tank connected to the top of the second distillation column through a condenser, and an alkyl anthracene heavy component tank connected to the bottom of the second distillation column; and

[0027] A condenser.

[0028] In the method provided by the present invention, in view of the characteristics of high boiling point and easy condensation of anthracene and anthracene alkylation products, a multi-stage vacuum distillation system with a baffle tank is adopted to prevent the distillation pipeline from being blocked by easily condensable substances while achieving efficient separation of anthracene alkylation reaction products.

[0029] In the method provided by the present invention, during distillation, a distillation solvent is introduced into the distillation column. Anthracene and anthracene precursor compounds gradually start to evaporate under distillation conditions. The solution formed by the distillation solvent and anthracene partially refluxes into the distillation column for repeated distillation, and part of it flows into the top product tank for collection; after the introduced distillation solvent enters the distillation column, it also starts to vaporize in large quantities and is distilled out together with anthracene and enters the top condenser for condensation. In the atmosphere of a large number of vaporized and liquefied distillation solvent molecules, anthracene and anthracene precursor compounds cannot undergo sublimation and solidification crystallization, but dissolve in the distillation solvent to form a solution and flow together, thus solving the problem that anthracene and anthracene precursor compounds easily block the top pipeline; the bottom product tank collects a series of alkyl anthracenes, and the baffle tank installed between the bottom product tank and the vacuum pipeline solves the problem of blockage of the bottom pipeline.

[0030] In the method provided by the present invention, through the introduction of the distillation solvent and the baffle tank, controlling its circulation between the top of the column and the top condenser, and at the same time regulating the feeding position, temperature and dosage, so that it dissolves anthracene to form a solution and is smoothly withdrawn together, which can not only achieve efficient separation of anthracene, but also solve the problem of high easy condensation during anthracene distillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a process flow diagram of a preferred specific embodiment of the method of the present invention;

[0032] Figure 2 is a schematic structural diagram of a preferred specific embodiment of the baffle tank of the present invention.

[0033] DESCRIPTION OF THE REFERENCE NUMERALS

[0034] 10 Tank body 11 Fluid separation chamber

[0035] 12 Fluid inlet pipe section 13 Fluid outlet pipe section

[0036] 14 Discharge port pipe section 15 Cylindrical section

[0037] 16 Reduced diameter section 20 Vertical baffle

[0038] 30 First distillation column 40 Second distillation column

[0039] 50 Product tank 51 Alkyl anthracene tank

[0040] 52 Monoalkyl anthracene tank 53 Alkyl anthracene heavy component tank

[0041] 60 Baffle tank 61 First baffle tank

[0042] 62 Second baffle tank 63 Third baffle tank

[0043] 64 Fourth baffle tank 70 Solvent tank

[0044] 80 Raw material tank 90 Condenser

[0045] 111 Fluid channel Detailed implementation mode

[0046] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0047] The inventors of the present invention have studied and found that the boiling point of anthracene is 340 °C. The alkyl anthracene products and anthracene homologues have a boiling point difference from each other, and product separation can be achieved through vacuum distillation technology. However, the technical difficulty lies in that the melting point of anthracene is as high as 215 °C. Separating high-melting-point anthracene solely by vacuum distillation technology has a large operation difficulty, and the pipeline is prone to clogging problems, affecting the continuous and stable operation of the process. In addition, anthracene is extremely prone to sublimation, and the sublimation process is difficult to control, significantly increasing the chance of pipeline blockage. In view of this, the inventors have provided the solution of the present invention.

[0048] As described above, the first aspect of the present invention provides a method for separating anthracene alkylation reaction products, and the method includes:

[0049] (1) In the presence of a solvent, introducing the feed liquid containing anthracene alkylation reaction products into the first distillation column 30 for vacuum distillation I to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds, and controlling the conditions of the vacuum distillation I so that the content of the alkyl anthracene component in the first distillate is not greater than 1.0 wt% and the content of the alkyl anthracene component in the first bottom product is not less than 99.0 wt%, and the alkyl anthracene component includes monoalkyl anthracene and alkyl anthracene heavy components;

[0050] (2) Introduce the first bottom product into the alkyl anthracene tank 51 for gas-liquid separation to obtain a first gas phase and a first liquid phase; introduce the first gas phase into the first baffle tank 61 for condensation treatment, and introduce the first liquid phase into the second distillation column 40 for vacuum distillation II to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene, and control the conditions of the vacuum distillation II so that the content of monoalkyl anthracene in the second top product is not less than 99.0 wt%.

[0051] (3) Introduce the second top product into the condenser 90 for condensation treatment to obtain a second gas phase and a second liquid phase respectively, reflux part of the second liquid phase to the second distillation column 40, and introduce the remaining part of the second liquid phase into the monoalkyl anthracene tank 52 for gas-liquid separation to obtain a third gas phase and a monoalkyl anthracene product; and

[0052] Introduce the second gas phase into the second baffle tank 62 for condensation treatment;

[0053] Introduce the third gas phase into the third baffle tank 63 for condensation treatment;

[0054] Introduce the second bottom product into the alkyl anthracene heavy component tank 53 for gas-liquid separation to obtain a fourth gas phase and an alkyl anthracene heavy component product; introduce the fourth gas phase into the fourth baffle tank 64 for condensation treatment;

[0055] Wherein, the structures of the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64 are the same or different, and each independently includes:

[0056] A tank body 10, internally provided with a fluid separation chamber 11; and

[0057] A vertical baffle 20, arranged in the fluid separation chamber 11 for separating fluids;

[0058] Wherein, a fluid inlet pipe section 12 extending from the circumferential side of the fluid separation chamber 11, a fluid outlet pipe section 13 extending from the top of the fluid separation chamber 11, and a discharge port pipe section 14 extending from the lowest point of the fluid separation chamber 11 are provided on the tank wall of the tank body 10.

[0059] In the present invention, the anthracene precursor compound represents an alkylating agent polymer, which refers to a mixture of components lighter than anthracene in the first distillate of the first distillation column.

[0060] In the present invention, the alkyl anthracene heavy component represents the component other than monoalkyl anthracene in alkyl anthracene.

[0061] In the present invention, introducing the first gas phase into the first baffle tank for condensation treatment, introducing the second gas phase into the second baffle tank for condensation treatment, introducing the third gas phase into the third baffle tank for condensation treatment, and introducing the fourth gas phase into the fourth baffle tank for condensation treatment are to separate and remove the residual anthracene and anthracene precursor compounds in the first gas phase, the second gas phase, the third gas phase, and the fourth gas phase from the product, thereby solving the problem that the anthracene and anthracene precursor compounds are likely to block the pipeline.

[0062] Preferably, in step (1), the conditions of the first vacuum distillation include: the liquid phase temperature is 250 - 350 °C, the gas phase temperature is 120 - 250 °C, the distillation pressure is 1 - 10 KPa, and the top reflux ratio is 0.1 - 4.

[0063] More preferably, in step (1), the conditions of the first vacuum distillation include: the liquid phase temperature is 280 - 320 °C, the gas phase temperature is 150 - 220 °C, the distillation pressure is 3 - 8 KPa, and the top reflux ratio is 0.2 - 2.

[0064] Preferably, in step (1), the conditions of the first vacuum distillation include: the total tower packing height is 1000 - 3000 mm, and more preferably 1200 - 2500 mm.

[0065] Preferably, in step (1), the feeding temperature of the solvent is 150 - 300 °C, and the ratio of the solvent dosage to the mass of anthracene in the feed liquid is 0.1 - 30:1.

[0066] More preferably, in step (1), the feeding temperature of the solvent is 180 - 280 °C, and the ratio of the solvent dosage to the mass of anthracene in the feed liquid is 1 - 15:1.

[0067] Preferably, the feeding position of the solvent is at the upper end of the top layer of the packing.

[0068] Preferably, in step (2), the conditions of the second vacuum distillation include: the liquid phase temperature is 250 - 400 °C, the gas phase temperature is 150 - 300 °C, the distillation pressure is 0.5 - 2 KPa, and the top reflux ratio is 0.1 - 4.

[0069] More preferably, in step (2), the conditions of the second vacuum distillation include: the liquid phase temperature is 300 - 350 °C, the gas phase temperature is 180 - 250 °C, the distillation pressure is 0.7 - 1.5 KPa, and the top reflux ratio is 0.2 - 2.

[0070] Preferably, in step (2), the conditions of the second vacuum distillation include: the total tower packing height is 1000 - 3000 mm, and more preferably 1200 - 2500 mm.

[0071] Preferably, the boiling point of the solvent is 200 - 340 °C.

[0072] More preferably, the solvent is selected from at least one of alkanes, halogenated hydrocarbons, aromatic hydrocarbons, alcohols, ketones, esters, and ethers, and the alkanes are selected from at least one of straight-chain alkanes and / or branched-chain alkanes having C 12 -C 19 of the straight-chain alkanes and / or branched-chain alkanes.

[0073] Preferably, the alkanes are selected from at least one of straight-chain alkanes and / or branched-chain alkanes having C 12 -C 17 of the straight-chain alkanes and / or branched-chain alkanes.

[0074] Preferably, the halogenated hydrocarbons are selected from at least one of trichlorobenzene, tetrachlorobenzene, tribromobenzene, tetrabromobenzene, chloro-C 10 -C 18 alkanes and bromo-C 10 -C 18 alkanes.

[0075] According to a preferred specific embodiment, the aromatic hydrocarbon is an alkyl-substituted benzene, and the total carbon number of the substituted alkyl groups is 4 - 12.

[0076] More preferably, the aromatic hydrocarbon is selected from at least one of butylbenzene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, triethylbenzene, tetraethylbenzene, dipropylbenzene, tripropylbenzene, dibutylbenzene, and dipentylbenzene.

[0077] According to another preferred specific embodiment, the aromatic hydrocarbon is a phenyl-substituted alkane.

[0078] More preferably, the aromatic hydrocarbon is selected from at least one of diphenylmethane and its alkyl-substituted derivatives, and diphenylethane and its alkyl-substituted derivatives.

[0079] Even more preferably, the aromatic hydrocarbon is selected from at least one of diphenylmethane, methyldiphenylmethane, and 1,2-diphenylethane.

[0080] According to another preferred specific embodiment, the aromatic hydrocarbon is naphthalene and / or an alkyl-substituted naphthalene, and the total carbon number of the substituted alkyl groups is 1 - 4.

[0081] More preferably, the aromatic hydrocarbon is selected from at least one of naphthalene, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, diethylnaphthalene, propylnaphthalene, methylethylnaphthalene, and butylnaphthalene.

[0082] Preferably, the alcohols are selected from at least one of benzyl alcohol, glycerol, diethylene glycol, triethylene glycol, and tetraethylene glycol.

[0083] Preferably, the ketone is selected from at least one of 1,1,3-trimethylcyclohexenone, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone.

[0084] Preferably, the ester is selected from at least one of dicarboxylic acid esters, ethyl benzoate, dimethyl phthalate, dibutyl phthalate, ethylene carbonate, propylene carbonate, and trioctyl phosphate.

[0085] Preferably, the ether is selected from at least one of ethylene glycol monophenyl ether, diethylene glycol monobutyl ether, diphenyl ether, and sulfolane.

[0086] Preferably, according to Figure 1 and Figure 2 as shown, the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64 each independently include a plurality of the vertical baffles 20. The plurality of vertical baffles 20 are sequentially and alternately spaced and connected at the vertical two ends of the tank body 10 to form a fluid channel 111 that extends circuitously. The fluid outlet pipe section 13 is located at the end of the fluid channel 111.

[0087] The inventors found that the number of baffles in the baffle tank should be determined comprehensively according to the material processing capacity and the content of anthracene and anthracene compounds in the material. The larger the material processing capacity and the higher the content of anthracene and anthracene compounds, the more baffles are required, so that anthracene and anthracene compounds can be intercepted more efficiently.

[0088] Preferably, the tank body 10 includes a cylindrical section 15 arranged vertically and a reduced-diameter section 16. The diameter of the reduced-diameter section 16 decreases from top to bottom, and the discharge port pipe section 14 is located at the lowest point of the reduced-diameter section 16.

[0089] Specifically, the tank body 10 is assembled vertically by the cylindrical section 15 and the reduced-diameter section 16. The upper opening of the reduced-diameter section 16 is large, and the lower opening is small. In this way, the condensed anthracene can be concentrated at the lowest point of the reduced-diameter section 16 and discharged from the discharge port pipe section 14, facilitating discharging.

[0090] Preferably, the reduced-diameter section 16 is in a hemispherical shape or a conical shape.

[0091] Preferably, the radius of the upper opening of the reduced-diameter section 16 is the same as the radius of the cylindrical section 15.

[0092] Preferably, the height of the cylindrical section 15 is 100 - 500 mm, and the radius of the cylindrical section 15 is 50 - 300 mm.

[0093] More preferably, the height of the cylindrical section 15 is 150 - 300 mm, and the radius of the cylindrical section 15 is 100 - 200 mm.

[0094] Preferably, the number of the vertical baffles 20 is 1 - 10.

[0095] More preferably, the number of the vertical baffles 20 is 2 - 5.

[0096] Preferably, the materials forming the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64 are each independently selected from at least one of stainless steel, plexiglass, and polyester resin.

[0097] Preferably, the stainless steel is selected from at least one of ferritic stainless steel, austenitic stainless steel, austenitic - ferritic duplex stainless steel, precipitation - hardening stainless steel, and martensitic stainless steel. The inventor found that selecting the tank body material in accordance with the principles of heat resistance and corrosion resistance to organic substances can make it more convenient for the discharge of anthracene and anthracene - like compounds.

[0098] Preferably, in the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64, independently of each other, the gas phase enters the tank body 10 from the fluid inlet pipe section 12, undergoes condensation and separation through the fluid separation chamber 11, and anthracene and homologues of anthracene are obtained from the discharge port pipe section 14.

[0099] The present invention exemplarily provides Figure 2 a schematic structural diagram to illustrate a preferred specific embodiment of the structures of the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64, wherein the first baffle tank 61, the second baffle tank 62, the third baffle tank 63, and the fourth baffle tank 64 each independently include:

[0100] a tank body 10, provided therein with a fluid separation chamber 11; and

[0101] vertical baffles 20, disposed in the fluid separation chamber 11 for separating fluids;

[0102] Among them, a fluid inlet pipe section 12 extending from the circumferential side of the fluid separation chamber 11, a fluid outlet pipe section 13 extending from the top of the fluid separation chamber 11, and a discharge port pipe section 14 extending from the lowest point of the fluid separation chamber 11 are provided on the tank wall of the tank body 10; two vertical baffles 20 are spaced and connected at the vertical two ends of the tank body 10 to form a circuitously extending fluid channel 111, and the fluid outlet pipe section 13 is located at the end of the fluid channel 111; the tank body 10 includes a cylindrical section 15 arranged vertically and a reduced-diameter section 16, the diameter of the reduced-diameter section 16 decreases from top to bottom, and the discharge port pipe section 14 is located at the lowest point of the reduced-diameter section 16; the reduced-diameter section 16 is in a hemispherical shape; the radius of the upper opening of the reduced-diameter section 16 is the same as the radius of the cylindrical section 15.

[0103] The following combines Figure 1 Provide a process flow of a preferred specific embodiment of the method for separating anthracene alkylation reaction products of the present invention:

[0104] The solvent from the solvent tank 70 and the liquid material containing the anthracene alkylation reaction product from the raw material tank 80 are respectively introduced into the first distillation tower 30 for vacuum distillation I to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds. Control the conditions of the vacuum distillation I so that the content of the alkyl anthracene component in the first distillate is not more than 1.0 wt% and the content of the alkyl anthracene component in the first bottom product is not less than 99.0 wt%. The alkyl anthracene component includes monoalkyl anthracene and alkyl anthracene heavy components;

[0105] The first bottom product is introduced into the alkyl anthracene tank 51 (product tank 50) for gas-liquid separation to obtain a first gas phase and a first liquid phase; the first gas phase is introduced into the first baffle tank 61 (baffle tank 60) for condensation treatment, and the first liquid phase is introduced into the second distillation tower 40 for vacuum distillation II to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene. Control the conditions of the vacuum distillation II so that the content of monoalkyl anthracene in the second top product is not less than 99.0 wt%;

[0106] The second top product is introduced into the condenser 90 for condensation treatment to respectively obtain a second gas phase and a second liquid phase, and a part of the second liquid phase is refluxed to the second distillation tower 40, and the remaining part of the second liquid phase is introduced into the monoalkyl anthracene tank 52 (product tank 50) for gas-liquid separation to obtain a third gas phase and a monoalkyl anthracene product; and

[0107] The second gas phase is introduced into the second baffle tank 62 (baffle tank 60) for condensation treatment;

[0108] The third gas phase is introduced into a third baffle tank 63 (baffle tank 60) for condensation treatment;

[0109] The second bottom product is introduced into an alkyl anthracene heavy component tank 53 (product tank 50) for gas-liquid separation to obtain a fourth gas phase and an alkyl anthracene heavy component product; the fourth gas phase is introduced into a fourth baffle tank 64 (baffle tank 60) for condensation treatment.

[0110] Under the preferred specific embodiments of the present invention, compared with the prior art, the method provided by the present invention can prevent the distillation pipeline from being blocked by easily condensable substances while achieving efficient separation of the anthracene alkylation reaction product.

[0111] As described above, the second aspect of the present invention provides a system for separating an anthracene alkylation reaction product, and the system includes:

[0112] A first distillation column 30, which is used to perform vacuum distillation I on a liquid material containing an anthracene alkylation reaction product therein to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds;

[0113] A second distillation column 40, which is in fluid communication with an alkyl anthracene tank 51 and is used to perform vacuum distillation II on a first liquid phase from the alkyl anthracene tank 51 therein to obtain a second bottom product containing an alkyl anthracene heavy component and a second top product containing monoalkyl anthracene;

[0114] A baffle tank 60, which includes a first baffle tank 61 in fluid communication with the alkyl anthracene tank 51, a second baffle tank 62 in fluid communication with a condenser 90, a third baffle tank 63 in fluid communication with a monoalkyl anthracene tank 52, and a fourth baffle tank 64 in fluid communication with an alkyl anthracene heavy component tank 53; the first baffle tank 61 is used to perform condensation treatment on a first gas phase from the alkyl anthracene tank 51 therein, the second baffle tank 62 is used to perform condensation treatment on a second gas phase from the condenser 90 therein, the third baffle tank 63 is used to perform condensation treatment on a third gas phase from the monoalkyl anthracene tank 52 therein, and the fourth baffle tank 64 is used to perform condensation treatment on a fourth gas phase from the alkyl anthracene heavy component tank 53 therein;

[0115] A product tank 50, which includes an alkyl anthracene tank 51 disposed on a pipeline between the first distillation column 30 and the second distillation column 40, a monoalkyl anthracene tank 52 connected to the top of the second distillation column 40 through a condenser 90, and an alkyl anthracene heavy component tank 53 connected to the bottom of the second distillation column 40; and

[0116] A condenser 90.

[0117] It should be noted that the distillation column in the present invention can adopt various distillation apparatuses well-known in the art. Exemplarily, it can be a sieve plate column or a packed column, and more preferably a packed column. The distillation process in the present invention can be intermittent or continuous.

[0118] The inventors found that installing a baffle tank at a position where anthracene and anthracene compounds are prone to condensation can better prevent the distillation pipeline from being blocked by easily condensable substances.

[0119] The present invention will be described in detail below through examples. Unless otherwise specified, the following examples all adopt the Figure 1 shown process flow.

[0120] In the following examples, various raw materials used are commercially available products unless otherwise specified.

[0121] In the following examples, the mass fraction (product purity) of the product is calculated by the gas chromatography peak area; the total product yield is calculated according to the following formula:

[0122]

[0123] Example 1

[0124] In this example, the feed liquid containing the anthracene alkylation reaction product was introduced into the first distillation column for distillation separation to obtain a distillate containing the alkylation solvent and a bottom product containing anthracene and a series of alkyl anthracene products. The distillation conditions included: the liquid phase temperature was 275 °C, the gas phase temperature was 170 °C, the distillation pressure was 5 KPa, the top reflux ratio was 0.5, and the total packed height of the column was 1600 mm. The feed temperature of the distillation solvent was 200 °C, and the ratio of the amount of the distillation solvent used to the mass of anthracene in the feed liquid was 1.5:1. The feed position of the distillation solvent was at the upper end of the top layer of the packing.

[0125] The mass fraction of the alkyl anthracene obtained at the top of the column was 2.5%, the mass fraction of the alkyl anthracene obtained at the bottom of the column was 97.5%, and the total yield of the alkyl anthracene product was 94%.

[0126] The bottom product of the first distillation column was introduced into the second distillation column for distillation separation to obtain a top product containing monoalkyl anthracene and a bottom product containing alkyl anthracene heavy components. The distillation conditions included: the liquid phase temperature was 308 °C, the gas phase temperature was 209 °C, the distillation pressure was 1.5 KPa, the top reflux ratio was 0.6, and the total packed height of the column was 1700 mm.

[0127] The mass fraction of the monoalkyl anthracene obtained at the top of the column was 96.2%, the mass fraction of the monoalkyl anthracene obtained at the bottom of the column was 7.5%, and the total yield of the monoalkyl anthracene product was 91%.

[0128] The system can still operate normally after continuous operation for 168 hours.

[0129] Example 2

[0130] This example is carried out by a method similar to that of Example 1, except that: the top reflux ratio of the first distillation column is 0.6, and the top reflux ratio of the second distillation column is 0.9.

[0131] The mass fraction of alkyl anthracene obtained at the top of the first distillation column is 2.4%, the mass fraction of alkyl anthracene obtained at the bottom of the column is 98.1%, and the total yield of the alkyl anthracene product is 94%.

[0132] The mass fraction of monoalkyl anthracene obtained at the top of the second distillation column is 97.1%, the mass fraction of monoalkyl anthracene obtained at the bottom of the column is 6.9%, and the total yield of the monoalkyl anthracene product is 91%.

[0133] The system can still operate normally after continuous operation for 168 hours.

[0134] Example 3

[0135] This example is carried out by a method similar to that of Example 1, except that: the top reflux ratio of the first distillation column is 0.7, and the top reflux ratio of the second distillation column is 1.2.

[0136] The mass fraction of alkyl anthracene obtained at the top of the first distillation column is 2.2%, the mass fraction of alkyl anthracene obtained at the bottom of the column is 98.5%, and the total yield of the alkyl anthracene product is 94%.

[0137] The mass fraction of monoalkyl anthracene obtained at the top of the second distillation column is 97.8%, the mass fraction of monoalkyl anthracene obtained at the bottom of the column is 6.1%, and the total yield of the monoalkyl anthracene product is 91%.

[0138] The system can still operate normally after continuous operation for 168 hours.

[0139] Example 4

[0140] This example is carried out by a method similar to that of Example 1, except that: the top reflux ratio of the first distillation column is 0.8, and the top reflux ratio of the second distillation column is 1.5.

[0141] The mass fraction of alkyl anthracene obtained at the top of the first distillation column is 2.0%, the mass fraction of alkyl anthracene obtained at the bottom of the column is 98.9%, and the total yield of the alkyl anthracene product is 94%.

[0142] The mass fraction of monoalkyl anthracene obtained at the top of the second distillation column is 98.6%, the mass fraction of monoalkyl anthracene obtained at the bottom of the column is 5.2%, and the total yield of the monoalkyl anthracene product is 91%.

[0143] The system can still operate normally after continuous operation for 168 hours.

[0144] Example 5

[0145] This example is carried out by a method similar to that of Example 1, except that: the top reflux ratio of the first distillation column is 1, and the top reflux ratio of the second distillation column is 1.8.

[0146] The mass fraction of alkyl anthracene obtained at the top of the first distillation column is 1.9%, the mass fraction of alkyl anthracene obtained at the bottom of the column is 99.3%, and the total yield of the alkyl anthracene product is 94%.

[0147] The mass fraction of monoalkyl anthracene obtained at the top of the second distillation column is 99.1%, the mass fraction of monoalkyl anthracene obtained at the bottom of the column is 4.3%, and the total yield of the monoalkyl anthracene product is 91%.

[0148] The system can still operate normally after continuous operation for 168 hours.

[0149] Example 6

[0150] This example is carried out by a method similar to that of Example 1, except that: the top reflux ratio of the first distillation column is 0.1, and the top reflux ratio of the second distillation column is 0.15.

[0151] The mass fraction of alkyl anthracene obtained at the top of the first distillation column is 4.9%, the mass fraction of alkyl anthracene obtained at the bottom of the column is 95.8%, and the total yield of the alkyl anthracene product is 94%.

[0152] The mass fraction of monoalkyl anthracene obtained at the top of the second distillation column is 95.3%, the mass fraction of monoalkyl anthracene obtained at the bottom of the column is 6.4%, and the total yield of the monoalkyl anthracene product is 91%.

[0153] The system can still operate normally after continuous operation for 168 hours.

[0154] Comparative Example 1

[0155] This comparative example is carried out by a method similar to that of Example 1, except that: a baffle tank is not installed in the system for separating the anthracene alkylation reaction product. Thus, the process flow of this comparative example is:

[0156] The feed liquid containing the anthracene alkylation reaction product is introduced into the first distillation column for distillation separation, and then the bottom product obtained is directly introduced into the second distillation column for distillation separation.

[0157] As a result, during the operation of the system, the system pressure gradually increases, and both the gas phase temperature and the liquid phase temperature gradually increase. The pipeline is severely blocked after the system has been continuously operated for 4 hours, resulting in abnormal operation and basically no product can be collected.

[0158] As can be seen from the above results, the method provided by the present invention can prevent the distillation pipeline from being blocked by easily condensable substances while achieving efficient separation of the anthracene alkylation reaction product.

[0159] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for separating the anthracene alkylation reaction product, characterized in that, the method comprises: (1) In the presence of a solvent, introducing the feed liquid containing the anthracene alkylation reaction product into the first distillation column (30) for vacuum distillation I to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds, controlling the conditions of the vacuum distillation I so that the content of the alkyl anthracene component in the first distillate is not more than 1.0 wt% and the content of the alkyl anthracene component in the first bottom product is not less than 99.0 wt%, and the alkyl anthracene component includes monoalkyl anthracene and alkyl anthracene heavy components; (2) Introducing the first bottom product into the alkyl anthracene tank (51) for gas-liquid separation to obtain a first gas phase and a first liquid phase; introducing the first gas phase into the first baffle tank (61) for condensation treatment, and introducing the first liquid phase into the second distillation column (40) for vacuum distillation II to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene, controlling the conditions of the vacuum distillation II so that the content of monoalkyl anthracene in the second top product is not less than 99.0 wt%; (3) Introducing the second top product into the condenser (90) for condensation treatment to respectively obtain a second gas phase and a second liquid phase, refluxing part of the second liquid phase to the second distillation column (40), and introducing the remaining part of the second liquid phase into the monoalkyl anthracene tank (52) for gas-liquid separation to obtain a third gas phase and a monoalkyl anthracene product; and introducing the second gas phase into the second baffle tank (62) for condensation treatment; introducing the third gas phase into the third baffle tank (63) for condensation treatment; introducing the second bottom product into the alkyl anthracene heavy component tank (53) for gas-liquid separation to obtain a fourth gas phase and an alkyl anthracene heavy component product; introducing the fourth gas phase into the fourth baffle tank (64) for condensation treatment; wherein, the boiling point of the solvent is 200 - 340 °C; wherein, the ratio of the solvent dosage to the mass of anthracene in the feed liquid is 1.5 - 30:1; wherein, the structures of the first baffle tank (61), the second baffle tank (62), the third baffle tank (63), and the fourth baffle tank (64) are the same or different, and each independently includes: a tank body (10) provided with a fluid separation chamber (11) inside; and a vertical baffle (20) disposed in the fluid separation chamber (11) for separating fluids; wherein, a fluid inlet pipe section (12) extending from the circumferential side of the fluid separation chamber (11), a fluid outlet pipe section (13) extending from the top of the fluid separation chamber (11), and a discharge port pipe section (14) extending from the lowest point of the fluid separation chamber (11) are provided on the tank wall of the tank body (10).

2. The method according to claim 1, wherein, in step (1), the conditions of the vacuum distillation I include: the liquid phase temperature is 250 - 350 °C, the gas phase temperature is 120 - 250 °C, the distillation pressure is 1 - 10 KPa, and the top reflux ratio is 0.1 - 4.

3. The method according to claim 1 or 2, Among them, In step (1), the conditions for the first vacuum distillation include: the liquid phase temperature is 280 - 320 °C, the gas phase temperature is 150 - 220 °C, the distillation pressure is 3 - 8 KPa, and the top reflux ratio is 0.2 - 2.

4. The method according to claim 1 or 2, Among them, In step (1), the feed temperature of the solvent is 150 - 300 °C.

5. The method according to claim 1 or 2, Among them, In step (1), the feed temperature of the solvent is 180 - 280 °C, and the ratio of the amount of the solvent to the mass of anthracene in the feed liquid is 1.5 - 15:

1.

6. The method according to claim 1 or 2, Among them, In step (2), the conditions for the second vacuum distillation include: the liquid phase temperature is 250 - 400 °C, the gas phase temperature is 150 - 300 °C, the distillation pressure is 0.5 - 2 KPa, and the top reflux ratio is 0.1 - 4.

7. The method according to claim 6, Among them, In step (2), the conditions for the second vacuum distillation include: the liquid phase temperature is 300 - 350 °C, the gas phase temperature is 180 - 250 °C, the distillation pressure is 0.7 - 1.5 KPa, and the top reflux ratio is 0.2 - 2.

8. The method according to claim 1 or 2, Among them, The solvent is selected from at least one of alkanes, halogenated hydrocarbons, aromatic hydrocarbons, alcohols, ketones, esters, and ethers.

9. The method according to claim 8, Among them, The alkane is selected from at least one of straight-chain alkanes and / or branched-chain alkanes having C 12 -C 19 .

10. The method according to claim 9, Among them, The alkane is selected from at least one of straight-chain alkanes and / or branched-chain alkanes having C 12 -C 17 .

11. The method according to claim 8, Among them, The halogenated hydrocarbon is selected from at least one of trichlorobenzene, tetrachlorobenzene, tribromobenzene, tetrabromobenzene, chloro C 10 -C 18 -alkane and bromo C 10 -C 18 -alkane.

12. The method according to claim 8, Among them, The aromatic hydrocarbon is an alkyl-substituted benzene, and the total carbon number of the substituted alkyl groups is 4 - 12.

13. The method according to claim 12, Among them, The aromatic hydrocarbon is selected from at least one of pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, triethylbenzene, tetraethylbenzene, dipropylbenzene, tripropylbenzene, dibutylbenzene, and dipentylbenzene.

14. The method according to claim 8, Among them, The aromatic hydrocarbon is a phenyl-substituted alkane.

15. The method according to claim 14, Among them, The aromatic hydrocarbon is selected from at least one of diphenylmethane and its alkyl-substituted derivatives, and 1,2-diphenylethane and its alkyl-substituted derivatives.

16. The method according to claim 15, Among them, The aromatic hydrocarbon is selected from at least one of diphenylmethane, methyldiphenylmethane, and 1,2-diphenylethane.

17. The method according to claim 8, Among them, The aromatic hydrocarbon is naphthalene and / or an alkyl-substituted naphthalene, and the total carbon number of the substituted alkyl groups is 1 - 4.

18. The method according to claim 17, Among them, The aromatic hydrocarbon is selected from at least one of naphthalene, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, diethylnaphthalene, propylnaphthalene, methylethylnaphthalene, and butylnaphthalene.

19. The method according to claim 8, Among them, The alcohol is selected from at least one of benzyl alcohol, glycerol, diethylene glycol, triethylene glycol, and tetraethylene glycol.

20. The method according to claim 8, Among them, The ketone is selected from at least one of 1,1,3-trimethylcyclohexenone, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone.

21. The method according to claim 8, wherein, The ester is selected from at least one of dimethyl formate, ethyl benzoate, dimethyl phthalate, dibutyl phthalate, ethylene glycol carbonate, propylene glycol carbonate, and trioctyl phosphate.

22. The method according to claim 8, wherein, The ether is selected from at least one of ethylene glycol monophenyl ether, diethylene glycol monobutyl ether, diphenyl ether, and sulfolane.

23. The method according to claim 1 or 2, wherein, The first baffle tank (61), the second baffle tank (62), the third baffle tank (63), and the fourth baffle tank (64) each independently include a plurality of the vertical baffles (20). The plurality of the vertical baffles (20) are sequentially and alternately connected at the vertical two ends of the tank body (10) to form a circuitously extending fluid passage (111), and the fluid outlet pipe section (13) is located at the end of the fluid passage (111).

24. The method according to claim 1 or 2, wherein, The tank body (10) includes a cylindrical section (15) arranged vertically and a reduced-diameter section (16). The diameter of the reduced-diameter section (16) decreases from top to bottom, and the discharge port pipe section (14) is located at the lowest point of the reduced-diameter section (16).

25. The method according to claim 24, wherein, The reduced-diameter section (16) is in a hemispherical shape or a conical shape.

26. The method according to claim 24, wherein, The height of the cylindrical section (15) is 100 - 500 mm, and the radius of the cylindrical section (15) is 50 - 300 mm.

27. The method according to claim 26, wherein, The height of the cylindrical section (15) is 150 - 300 mm, and the radius of the cylindrical section (15) is 100 - 200 mm.

28. The method according to claim 23, wherein, The number of the vertical baffles (20) is 1 - 10.

29. The method according to claim 28, wherein, The number of the vertical baffles (20) is 2 - 5.

30. The method according to claim 1 or 2, wherein, The materials forming the first baffle tank (61), the second baffle tank (62), the third baffle tank (63), and the fourth baffle tank (64) are each independently selected from at least one of stainless steel, plexiglass, and polyester resin.

31. The method according to claim 30, wherein, The stainless steel is selected from at least one of ferritic stainless steel, austenitic stainless steel, austenitic-ferritic duplex stainless steel, precipitation hardening stainless steel, and martensitic stainless steel.

32. The method according to claim 1 or 2, wherein, In the first baffle tank (61), the second baffle tank (62), the third baffle tank (63), and the fourth baffle tank (64), independently of each other, the gas phase enters the tank body (10) from the fluid inlet pipe section (12), undergoes condensation and separation through the fluid separation chamber (11), and anthracene and homologues of anthracene are obtained from the discharge port pipe section (14).

33. A system for separating anthracene alkylation reaction products, characterized in that, the system comprises: a first distillation column (30) for subjecting a liquid material containing anthracene alkylation reaction products to vacuum distillation I therein to obtain a first bottom product and a first distillate containing anthracene and anthracene precursor compounds; a second distillation column (40) in fluid communication with the alkyl anthracene tank (51) for subjecting a first liquid phase from the alkyl anthracene tank (51) to vacuum distillation II therein to obtain a second bottom product containing alkyl anthracene heavy components and a second top product containing monoalkyl anthracene; a baffle tank (60) including a first baffle tank (61) in fluid communication with the alkyl anthracene tank (51), a second baffle tank (62) in fluid communication with the condenser (90), a third baffle tank (63) in fluid communication with the monoalkyl anthracene tank (52), and a fourth baffle tank (64) in fluid communication with the alkyl anthracene heavy component tank (53); the first baffle tank (61) is used for condensing a first gas phase from the alkyl anthracene tank (51) therein, the second baffle tank (62) is used for condensing a second gas phase from the condenser (90) therein, the third baffle tank (63) is used for condensing a third gas phase from the monoalkyl anthracene tank (52) therein, and the fourth baffle tank (64) is used for condensing a fourth gas phase from the alkyl anthracene heavy component tank (53) therein; a product tank (50) including an alkyl anthracene tank (51) disposed on a pipeline between the first distillation column (30) and the second distillation column (40), a monoalkyl anthracene tank (52) connected to the top of the second distillation column (40) through a condenser (90), and an alkyl anthracene heavy component tank (53) connected to the bottom of the second distillation column (40); and a condenser (90).

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