阅读说明：本技术 一种含双环戊二烯的粗苯加氢精制提取环戊烷工艺 (Process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene ) 是由 张先茂 夏大寒 王瑜 王泽� 王国兴 陈凯 王栋斌 金建涛 郑峰伟 周正 瞿玖 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种含双环戊二烯的粗苯加氢精制提取环戊烷工艺,该方法对一种含双环戊二烯的粗苯原料进行预处理、加氢精制、环戊烷蒸馏精制、芳烃分离与精制,分离出纯度＞99.9%的环戊烷、硫含量＜0.5ppm的精苯、甲苯、混二甲苯,使产品价值最大化,实现工艺的最大经济效益。(The invention discloses a process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene, which comprises the steps of pretreating a crude benzene raw material containing dicyclopentadiene, hydrofining, distilling and refining cyclopentane, separating and refining aromatic hydrocarbon, separating cyclopentane with the purity of more than 99.9%, refined benzene with the sulfur content of less than 0.5ppm, toluene and mixed xylene, maximizing the product value and realizing the maximum economic benefit of the process.)

1. A process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene is characterized in that: crude benzene is derived from a byproduct of coal gas production, the mass content of dicyclopentadiene is 10-14%, and the bromine number is 45-72 gBr₂100g of diene, 8.9-15 gI₂100g of; the crude benzene is subjected to raw material pretreatment, hydrofining, cyclopentane distillation refining, aromatic hydrocarbon separation and refining to prepare cyclopentane, benzene, toluene, xylene and non-aromatic hydrocarbon, and the specific process comprises the following steps:

(a) pretreatment of raw materials:filtering a crude benzene raw material containing dicyclopentadiene, feeding the crude benzene raw material into a de-heavy tower (2) through a buffer tank (1), removing heavy components with more than nine carbon atoms at the bottom of the de-heavy tower (2), pyrolyzing dicyclopentadiene to generate cyclopentadiene, and separating benzene front components containing dicyclopentadiene and being lower than 80 ℃ from the tower topHeavy components with the temperature of more than or equal to 80 ℃ are separated from the side line of the tower(ii) a Benzene front componentAnd heavy componentsRespectively entering a hydrofining unit for reaction;

(b) and (3) hydrofining: hydrofining adopts low-temperature low-pressure high-space velocity three-stage hydrogenation process, and the separated benzene front componentMixed with hydrogen and then enters a first-stage hydrogenation reactor (3) from top to bottom, the first-stage hydrogenation reaction is a reduction state Ni-S catalyst, and the saturated benzene front componentHydrogenating cyclopentadiene to produce cyclopentene and cyclopentane; benzene front component after first-stage hydrogenationHeavy componentMixing with hydrogen, exchanging heat with a heat exchanger, entering a second-stage hydrogenation reactor (4) from top to bottom, performing second-stage hydrogenation reaction to obtain a sulfurized Ni-Mo catalyst, and performing hydrogenation saturationResidual olefins in the feedstock; the components after the second-stage hydrogenation are mixed with hydrogen, then the mixture is subjected to heat exchange by a heat exchanger, then the mixture enters a heating furnace for heating, then the mixture enters a three-stage hydrogenation reactor (5) from top to bottom for desulfurization and denitrification refining, sulfur and nitrogen impurities in the mixture are removed by hydrogenation, the three-stage hydrogenation reaction is a sulfide Co-Mo catalyst, and H is generated by hydrogenation and contains H₂S gas and benzene front components are separated from the top of the stabilizer (6), and heavy components at the bottom of the stabilizer (6) are sent to an aromatic pre-distillation tower (8);

(c) and (3) distillation and refining of cyclopentane: introducing an outlet material at the top of the stabilizing tower (6) into a cyclopentane separation tower (7), wherein a material at the bottom of the cyclopentane separation tower (7) is a cyclopentane pure product, and a material at the top of the cyclopentane separation tower (7) is a light component in benzene front components;

(d) aromatic hydrocarbon separation and refining: the components at the bottom of the stabilizer (6) enter an aromatic pre-distillation tower (8) for separation, and BT fraction containing benzene and toluene extracted from the top of the aromatic pre-distillation tower (8) enters an extractive distillation tower (10); the top discharge of the extractive distillation tower (10) is the extraction solvent oil, the bottom of the extractive distillation tower (10) is the mixed oil rich in aromatic hydrocarbon and extractant, and the mixed oil enters an extractant recovery tower (11) after heat exchange; after the extraction agent is separated by the extraction agent recovery tower (11), BT and a small amount of alkane are arranged at the top of the extraction agent recovery tower (11), an extraction agent is arranged at the bottom of the extraction agent recovery tower (11), the extraction agent returns to the extraction rectification tower (10) after heat exchange, and materials at the top of the extraction agent recovery tower (11) enter a benzene refining tower (12); pure benzene is separated from the top of the refined benzene tower (12), toluene and a small amount of benzene and methylcyclohexane are discharged from the bottom of the refined benzene tower (12), and the discharged from the bottom of the refined benzene tower (12) is sent to a toluene tower (13); separating a small amount of benzene and methylcyclohexane mixture from the top of the toluene tower (13), and recycling the mixture to the previous working section, wherein the tower kettle of the toluene tower (13) is a qualified toluene product; the XS fraction at the bottom of the aromatic hydrocarbon pre-distillation tower (8) enters a xylene distillation tower (9), C5 fraction is extracted at the top of the tower, C9 component is extracted at the bottom of the tower, and xylene products are extracted at the side line of the aromatic hydrocarbon pre-distillation tower (8).

2. The method of claim 1, wherein the dicyclopentadiene-containing crude benzene is hydrorefined to extract cyclopentaneThe process is characterized in that: in the step (a), crude benzene containing dicyclopentadiene is filtered and enters a heavy component removal tower (2) from a buffer tank (1), dicyclopentadiene is pyrolyzed in a tower kettle of the heavy component removal tower (2) to generate cyclopentadiene, and benzene front component containing cyclopentadieneDistilling from the top of the heavy component removal tower (2), and hydrogenating cyclopentadiene in a first-stage hydrogenation reactor to prepare cyclopentane.

3. The process for hydrofining and extracting cyclopentane from dicyclopentadiene-containing crude benzene, which is characterized by comprising the following steps: in the step (b), the catalyst used in the first-stage hydrogenation is a Ni-S catalyst, and the catalyst is reduced and used, wherein the reaction conditions are that the temperature is 10-90 ℃, the pressure is 2.0-4.0 MPa, and the airspeed is 0.5-2.0 h^-1And the volume ratio of hydrogen to oil is 400-800: 1.

4. The process for hydrofining and extracting cyclopentane from crude benzene containing dicyclopentadiene as claimed in claim 1, wherein in step (b), the catalyst used in the second stage hydrogenation is Ni-Mo catalyst, and the catalyst is used after vulcanization, and the reaction conditions are 160-190 ℃, 2.0-4.0 MPa pressure and 0.5-2.0 h airspeed^-1And the volume ratio of hydrogen to oil is 400-800: 1.

5. The process for hydrofining and extracting cyclopentane from dicyclopentadiene-containing crude benzene, which is characterized by comprising the following steps: in the step (b), the catalyst used in the three-stage hydrogenation is a Co-Mo catalyst, and the catalyst is used after vulcanization, wherein the reaction conditions are that the temperature is 240-320 ℃, the pressure is 2.0-4.0 MPa, and the airspeed is 0.5-2.0 h^-1And the volume ratio of hydrogen to oil is 400-800: 1.

6. The process for hydrofining and extracting cyclopentane from dicyclopentadiene-containing crude benzene, which is characterized by comprising the following steps: the temperature of a tower kettle of the pentane separation tower (7) is 70-74 ℃, the temperature of a tower top is 62-66 ℃, the system pressure is 0.04-0.10 MPa, the reflux ratio is 1.4-2.8, the tower kettle material of the pentane separation tower (7) is a pure cyclopentane product, the mass content of cyclopentane in the tower kettle is not less than 99.9%, the tower top material of the pentane separation tower (7) is a light component in a mixed cyclopentane component, and the mass content of cyclopentane in the tower top is not more than 2.5%.

Technical Field

The invention belongs to the technical field of coal chemical industry, and particularly relates to a process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene.

Background

The crude benzene containing dicyclopentadiene is a byproduct of novel coal chemical industry such as coal-made natural gas, coal-made oil, coal-made methanol and the like, mainly comprises components such as aromatic hydrocarbon, dicyclopentadiene and alkane, and has a boiling range of 40-180 ℃. The crude benzene contains dicyclopentadiene about 12%, pure benzene about 25%, toluene, xylene and the like about 10%, and olefin about 40-90 gBr₂100g, the diene value is 5-15 gI₂100g, sulfur content over 3000 ppm. The crude benzene contains a large amount of dicyclopentadiene, aromatic hydrocarbon and other high value-added petrochemical products, wherein dicyclopentadiene is pyrolyzed to produce cyclopentadiene, and then cyclopentane is prepared by hydrogenation. Cyclopentane can replace the fluorinion which has destructive effect on the atmosphereHydrocarbons (CFCS) are used in refrigeration products to benefit the protection of the ozone layer, and cyclopentane is a common organic solvent in the chemical industry. After the cyclopentane is extracted by the treatment of the hydrogenation product, the aromatic hydrocarbon is separated, the benzene, the toluene and the mixed xylene are separated, the product value is maximized, and the maximum economic benefit is realized.

Patent CN105219422B reports a composite extractant suitable for coal-based naphtha and a method for preparing solvent oil, wherein the solvent oil is prepared by using coal-based naphtha as a raw material and performing countercurrent extraction in an extraction tower and then fractionating, and in the example, the sulfur content in the coal-based naphtha is less than 10 ppm. Patent CN106433777B reports a method for preparing monomer cycloparaffins and solvent oil from coal-based naphtha, in which coal-based naphtha and hydrogen are mixed and then enter a hydrodesulfurization reactor and an aromatic hydrogenation saturation reactor for hydrotreating, and then the hydrotreated product is subjected to extractive distillation to obtain high value-added products such as cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, solvent oil No. 6 and solvent oil No. 120, respectively, and the main products of the method are cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, and the like. In patent CN106635139B, an Ni-W-Cu catalyst is applied to a mixture of crude benzene and coal-based naphtha, the active component of the catalyst is mainly Ni-W-Cu-Sm-P, the use temperature is 80-110 ℃, the pressure is 2.0 MPa-3.0 MPa, and the airspeed is 1-2 h^-1And styrene, diolefin and other easily-coked substances in the oil product can be basically and completely removed under the condition that the volume ratio of hydrogen to oil is 50: 1-100: 1, the saturation rate of mono-olefin is more than 20%, and the problem of rapid coking in a subsequent high-temperature working section is solved, wherein the introduction related to cyclopentadiene hydrogenation is not included. Patent CN104974006B describes a full-fraction crude benzene hydrogenation process, which is to divide crude benzene into crude benzene I and crude benzene II, increase the reaction temperature step by step from low temperature of 70 ℃ through a three-stage hydrogenation process, remove unsaturated substances such as styrene, diolefin and the like in the crude benzene, and then prepare non-aromatic hydrocarbon, benzene, toluene, xylene and heavy benzene products through two-stage and three-stage hydrogenation, wherein the process does not produce products related to pentane. Up to now, no studies have been reported on the hydrogenation of crude benzene containing dicyclopentadiene to extract cyclopentane.

Disclosure of Invention

The invention aims to provide a process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene, which is suitable for industrialization. In order to achieve the purpose, the invention adopts the following technical scheme:

a process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene comprises the following steps:

(1) pretreatment of raw materials: filtering a crude benzene raw material containing dicyclopentadiene, feeding the crude benzene raw material into a de-heavy tower 2 through a buffer tank 1, removing heavy components with more than nine carbons at the bottom of the de-heavy tower 2, pyrolyzing the dicyclopentadiene to generate cyclopentadiene, separating a benzene front component I containing dicyclopentadiene and being lower than 80 ℃, and separating a heavy component II being higher than or equal to 80 ℃ from a tower side line; the benzene front component I and the heavy component II respectively enter a hydrofining unit for reaction.

(2) And (3) hydrofining: the hydrogenation part adopts a low-temperature low-pressure high-space velocity three-stage hydrofining process, the separated benzene front component I and hydrogen are mixed and then enter a first-stage hydrogenation reactor 3 from top to bottom, the first-stage hydrogenation reaction is a reduction state Ni-S catalyst and is used after reduction, the reaction conditions are that the temperature is 10-90 ℃, the pressure is 2.0-4.0 MPa, and the space velocity is 0.5-2.0 h^-1The volume ratio of hydrogen to oil is 400-800: 1, and in the saturated benzene front component I, diolefin is hydrogenated to generate cyclopentene and cyclopentane; mixing the benzene front component I and the heavy component II after the first-stage hydrogenation with hydrogen, exchanging heat through a heat exchanger, and then entering a second-stage hydrogenation reactor 4 from top to bottom, wherein the second-stage hydrogenation reaction is a vulcanized Ni-Mo catalyst and is used after vulcanization, and the reaction conditions are that the temperature is 160-190 ℃, the pressure is 2.0-4.0 MPa, and the airspeed is 0.5-2.0 h^-1Adding residual olefin in the hydrogen-oil volume ratio of 400-800: 1 to the hydrogen-saturated raw material; the components after the second-stage hydrogenation are mixed with hydrogen, then the mixture is subjected to heat exchange by a heat exchanger, then the mixture enters a heating furnace for heating, then the mixture enters a three-stage hydrogenation reactor 5 from top to bottom for desulfurization and denitrification refining, sulfur and nitrogen impurities in the mixture are removed by hydrogenation, the three-stage hydrogenation reaction is a vulcanized Co-Mo catalyst and is used after vulcanization, and the reaction condition is that the reaction is carried out under the condition thatThe temperature is 240-320 ℃, the pressure is 2.0-4.0 MPa, and the airspeed is 0.5-2.0 h^-1The volume ratio of hydrogen to oil is 400-800: 1, and H is contained in the hydrogen generated by hydrogenation₂S gas and benzene front components are separated from the top of the stabilizer 6, and heavy components at the bottom of the stabilizer 6 are sent to an aromatic pre-distillation tower 8.

(3) And (3) distillation and refining of cyclopentane: introducing an outlet material at the top of the stabilizing tower 6 into a cyclopentane separating tower 7, wherein the temperature of a tower kettle of the cyclopentane separating tower 7 is 70-74 ℃, the temperature of the top of the cyclopentane separating tower 7 is 62-66 ℃, the system pressure is 0.04-0.10 MPa, the reflux ratio is 1.4-2.8, the material at the tower kettle of the cyclopentane separating tower 7 is a pure cyclopentane, and the material at the top of the cyclopentane separating tower 7 is a light component in the benzene front component.

(4) Aromatic hydrocarbon separation and refining: the components at the bottom of the stabilizer 6 enter an aromatic pre-distillation tower 8 for separation, and BT fractions containing benzene and toluene extracted from the top of the aromatic pre-distillation tower 8 enter an extractive distillation tower 10; the top discharge of the extractive distillation tower 10 is the extraction solvent oil, the bottom of the extractive distillation tower 10 is the mixed oil rich in aromatic hydrocarbon and extractant, and the mixed oil enters the extractant recovery tower 11 after heat exchange; after the extraction agent is separated by the extraction agent recovery tower 11, BT and a small amount of alkane are arranged at the top of the extraction agent recovery tower 11, the extraction agent is arranged at the bottom of the extraction agent recovery tower 11, the extraction agent returns to the extraction rectification tower 10 after heat exchange, and the materials at the top of the extraction agent recovery tower 11 enter the benzene refining tower 12; pure benzene is separated from the top of the refined benzene tower 12, the discharge of the tower bottom of the refined benzene tower 12 is toluene and a small amount of benzene and methylcyclohexane, and the discharge of the tower bottom of the refined benzene tower 12 is sent to a toluene tower 13; separating a small amount of benzene and methylcyclohexane mixture from the top of the toluene tower 13, circulating the mixture to the previous working section, and obtaining a qualified toluene product at the bottom of the toluene tower 13; the XS fraction at the bottom of the aromatic hydrocarbon pre-distillation tower 8 enters a xylene distillation tower 9, the C5 fraction is extracted at the top of the tower, the C9 component is extracted at the bottom of the tower, and a xylene product is extracted at the side line of the aromatic hydrocarbon pre-distillation tower 8.

(5) Crude benzene containing dicyclopentadiene enters a heavy component removal tower 2 from a buffer tank 1 after being filtered, dicyclopentadiene is pyrolyzed in a tower kettle of a distillation tower 2 to generate cyclopentadiene, a benzene front component I containing cyclopentadiene is distilled out from the tower top of the heavy component removal tower 2, and cyclopentane is prepared by hydrogenation through a first-stage hydrogenation reactor.

(6) The temperature of a tower kettle of the pentane separation tower 7 is 70-74 ℃, the temperature of a tower top is 62-66 ℃, the system pressure is 0.04-0.10 MPa, the reflux ratio is 1.4-2.8, the tower kettle material of the pentane separation tower 7 is a pure cyclopentane product, the mass content of cyclopentane in the tower kettle is not less than 99.9%, the tower top material of the pentane separation tower 7 is a light component in a mixed cyclopentane component, and the mass content of cyclopentane in the tower top is not more than 2.5%.

The process for extracting cyclopentane by hydrofining crude benzene containing dicyclopentadiene provided by the invention has the following advantages:

(1) the method comprises the steps of carrying out pyrolysis separation pretreatment on raw materials, separating a benzene front component I containing cyclopentadiene and a heavy component II, carrying out hydrogenation saturation on cyclopentadiene in the benzene front component I in a first-stage hydrogenation reactor to generate cyclopentane, mixing the cyclopentane with the heavy component II in a second-stage hydrogenation reactor to hydrogenate and saturate all olefins, then entering a third-stage hydrogenation reactor to carry out hydrodesulfurization and denitrification, finally carrying out separation and extraction on cyclopentane, benzene, toluene, xylene and the like, and maximizing the product value through finish machining.

(2) In the raw material pretreatment process of the method, dicyclopentadiene is heated and depolymerized at 170 ℃ to produce cyclopentadiene, and the cyclopentadiene enters a first-stage low-temperature hydrogenation from the top of a distillation tower along with a benzene front component I, the cyclopentadiene is subjected to low-temperature hydrogenation to release heat, an activation temperature is provided for olefin hydrogenation of a bed layer under a first-stage catalyst, a heater is omitted, coking of the heater is avoided, cyclopentane is produced after cyclopentadiene hydrogenation, and the added value of a product is improved; meanwhile, aromatic hydrocarbons such as benzene, toluene and xylene are separated and then enter the heavy component II, so that the phenomenon that the aromatic hydrocarbons are saturated in the first-stage hydrogenation process to cause temperature runaway of the reaction is avoided.

(3) In the method, in the three-stage hydrogenation process, cyclopentadiene in the benzene front component I is saturated in a first-stage hydrogenation reactor to generate cyclopentane, all olefins in the saturated heavy component II of a second-stage reactor and the benzene front component I after being mixed are subjected to first-stage hydrogenation reaction and second-stage hydrogenation reaction, the olefins in the raw materials are completely removed, the three-stage hydrogenation reactor is subjected to desulfurization and denitrification, the reaction heat is easy to control, aromatic hydrocarbon loss caused by aromatic hydrocarbon saturation is avoided, the reaction heat can be well distributed through the three-stage hydrogenation process, and the energy consumption of the whole reaction is lowest under the condition of ensuring the optimal product quality.

(4) The method has the advantages that after the crude benzene containing dicyclopentadiene is subjected to hydrotreating, separation and refining, the purity of the product, namely the cyclopentadiene, is more than 99.9 percent, the sulfur content of the refined benzene is less than 0.5ppm, and the added value of the product is improved.

Drawings

FIG. 1 is a schematic diagram of a process flow for extracting cyclopentane from crude benzene containing dicyclopentadiene by hydrogenation. The definition of each label in fig. 1 is:

1 is a buffer tank; 2 is a de-weighting tower; 3 is a first-stage hydrogenation reactor; 4 is a two-stage hydrogenation reactor: 5 is a three-section hydrogenation reactor; 6 is a stabilizing tower; 7 is a cyclopentane separation tower; 8 is an aromatic hydrocarbon pre-distillation tower; 9 is a xylene distillation column; 10 is an extraction rectifying tower; 11 is an extractant recovery tower; 12 is a refined benzene tower; 13 is a toluene column.

Detailed Description

The technical scheme provided by the invention is completely explained in detail by combining the drawings and the specific examples as follows:

the raw materials are treated by the flow in the attached figure, products such as cyclopentane, refined benzene, toluene, xylene and the like are separated, the properties of the raw materials are shown in a table 1, and the properties of the products are shown in a table 2. The crude benzene containing dicyclopentadiene is from a byproduct of a coal gas production device, the first raw material is from a byproduct crude benzene of coal gas production in Guanghui of Xinjiang, the second raw material is from a byproduct crude benzene of coal gas production in Qinghua of Xinjiang, the third raw material is a sample obtained by mixing the first raw material and the second raw material by 50% by mass, and the properties of the sample are shown in Table 1:

TABLE 1 Properties relating to raw materials

Properties of	Raw material one	Raw material II	Raw material III
				Density, g/ml	0.756	0.837	0.801
Distillation range, 10%/50%/100%	37℃/79℃/130℃	54℃/82℃/160℃	43℃/81℃/160℃
				Bromine number, gBr2Per 100g oil	72	45	56
Diene number, gI2Per 100g oil	15	8.9	11.95
				Total sulfur, ppm	3306	2304	2800
Total nitrogen, ppm	239	940	590
				Dicyclopentadiene, wt.%	10	14	12
Benzene, wt%	24	58.1	41
				Toluene, wt.%	9.2	20.8	15
Xylene, wt.%	2	4.9	3.45

Example 1:

filtering the first raw material, feeding the filtered first raw material into a de-weighting tower 2 through a buffer tank 1, removing heavy components with more than nine carbon atoms at the bottom of the de-weighting tower 2, pyrolyzing dicyclopentadiene to generate cyclopentadiene, separating a benzene front component I with the temperature of less than 80 ℃ and containing cyclopentadiene from the top of the de-weighting tower 2, and separating a heavy component II with the temperature of more than or equal to 80 ℃ from a side line of the de-weighting tower 2; separated benzene front componentMixed with hydrogen and then enters a first-stage hydrogenation reactor 3 from top to bottom, and first-stage hydrogenation is carried outIs a Ni-S reduction catalyst, and has the reaction temperature of 10 ℃, the pressure of 4.0MPa and the space velocity of 2.0h^-1Carrying out reaction under the condition that the volume ratio of hydrogen to oil is 400:1, saturating diolefin in the benzene front component I, and hydrogenating cyclopentadiene to generate cyclopentene and cyclopentane; the benzene front component I, the heavy component II and hydrogen are mixed after hydrogenation, heat exchange is carried out by a heat exchanger, then the mixture enters a second-stage hydrogenation reactor 4 from top to bottom, the second-stage hydrogenation reaction is sulfuration state Ni-Mo, the reaction temperature is 160 ℃, the pressure is 4.0MPa, and the space velocity is 2.0h^-1Saturating the residual olefin in the raw material under the condition that the volume ratio of hydrogen to oil is 400: 1; the components after the second-stage hydrogenation are mixed with hydrogen, then the mixture is subjected to heat exchange by a heat exchanger, then the mixture enters a heating furnace for heating, then the mixture enters a three-stage hydrogenation reactor 5 from top to bottom for desulfurization and denitrification refining, and a Co-Mo catalyst for the three-stage hydrogenation reaction is prepared at the reaction temperature of 320 ℃, the pressure of 4.0MPa and the space velocity of 2.0h^-1Under the condition that the volume ratio of hydrogen to oil is 400:1, removing sulfur and nitrogen impurities in the oil by hydrogenation; h-containing produced by hydrogenation₂S gas and benzene front components are separated from the top of the stabilizer 6, and heavy components at the bottom of the stabilizer 6 are sent to an aromatic pre-distillation tower 8. And (3) introducing an outlet material at the top of the stabilizing tower 6 into a cyclopentane separation tower 7, wherein the temperature of a tower kettle of the cyclopentane separation tower 7 is 70 ℃, the temperature of the top of the cyclopentane separation tower is 62 ℃, the system pressure is 0.04MPa, the reflux ratio is 1.4, the tower kettle material of the pentane separation tower 7 is a pure cyclopentane product, the content of cyclopentane is 99.99%, the tower top material of the pentane separation tower 7 is a light component in the benzene front component, and the content of cyclopentane at the top of the pentane separation tower 7 is 2.5%. The components at the bottom of the stabilizer 6 enter an aromatic pre-distillation tower 8, and the BT fraction containing benzene and toluene at the top of the aromatic pre-distillation tower 8 enters an extractive distillation tower 10; the top discharge of the extractive distillation tower 10 is the extraction solvent oil, the bottom of the extractive distillation tower 10 is the mixed oil rich in aromatic hydrocarbon and extractant, and the mixed oil enters the extractant recovery tower 11 after heat exchange; after the separation by the extractant recovery tower 11, BT and a small amount of alkane are at the top of the extractant recovery tower 11, extractant is at the bottom of the extractant recovery tower 11, the extractant is subjected to heat exchange and then returns to the extraction rectification tower 10, and BT and a small amount of alkane evaporated at the top of the extractant recovery tower 11 enter the benzene refining tower 12; pure benzene is evaporated from the top of the refined benzene tower 12, the content of pure benzene sulfur is 0.3ppm, and toluene and a small amount of benzene and methylcyclohexane are discharged from the tower bottom of the refined benzene tower 12; the material is fed to a toluene column 13, in which toluene column 13A small amount of benzene and methylcyclohexane mixture is evaporated from the tower top and recycled to the previous working section, and the tower kettle is a qualified toluene product; the XS fraction at the bottom of the aromatic hydrocarbon pre-distillation column 8 enters a xylene distillation column 9, the C5 fraction is extracted from the top of the xylene distillation column 9, the C9 component is extracted from the bottom of the xylene distillation column 9, and a xylene product is extracted from the side line of the column.

Example 2:

filtering the raw material II, feeding the filtered raw material II into a de-heavy tower 2 through a buffer tank 1, removing heavy components with more than nine carbon atoms in the unit, pyrolyzing dicyclopentadiene to produce cyclopentadiene, separating by distillation to obtain a benzene front component I with the temperature of less than 80 ℃ at the top of the de-heavy tower 2, and separating a heavy component II with the temperature of more than or equal to 80 ℃ from a side line of the tower; the benzene front component I and the heavy component II respectively enter a hydrofining unit for reaction. The hydrogenation part adopts a low-temperature low-pressure high-space velocity three-stage hydrofining process, the separated benzene front component I is mixed with hydrogen and then enters a first-stage hydrogenation reactor 3 from top to bottom, the first-stage hydrogenation is a Ni-S reduction catalyst, and the reaction conditions are that the temperature is 90 ℃, the pressure is 2.0MPa and the space velocity is 0.5h^-1Reacting hydrogen and oil in a volume ratio of 800:1, and hydrogenating diolefin in a saturated benzene front component I to generate cyclopentene and cyclopentane; the benzene front component I, the heavy component II and hydrogen are mixed after hydrogenation, heat exchange is carried out by a heat exchanger, then the mixture enters a second-stage hydrogenation reactor 4 from top to bottom, the second-stage hydrogenation reaction is sulfuration state Ni-Mo, the reaction condition is that the temperature is 190 ℃, the pressure is 2.0MPa, and the airspeed is 0.5h^-1Hydrogenation is carried out on the hydrogen-oil volume ratio of 800: 1; saturating the remaining olefins in the feed; the components after the second-stage hydrogenation are mixed with hydrogen, then heat exchange is carried out by a heat exchanger, the mixture enters a heating furnace for heating, and then the mixture enters a third-stage hydrogenation reactor 5 from top to bottom for desulfurization and denitrification refining; the Co-Mo catalyst for three-stage hydrogenation reaction is prepared at the reaction temperature of 240 ℃, the pressure of 2.0MPa and the airspeed of 0.5h^-1Under the condition that the volume ratio of hydrogen to oil is 800:1, removing sulfur and nitrogen impurities in the oil by hydrogenation; h-containing produced by hydrogenation₂S gas and benzene front components are separated from the top of the stabilizer 6, and heavy components at the bottom of the stabilizer 6 are sent to an aromatic pre-distillation tower 8. Introducing the outlet material at the top of the stabilizing tower 6 into a cyclopentane separating tower 7, wherein the tower kettle temperature of the cyclopentane separating tower 7 is 74 ℃, the tower top temperature is 66 ℃, the system pressure is 0.10MPa, and the reflux ratio is 28, the tower bottom material of the pentane separation tower 7 is a cyclopentane pure product, the content of cyclopentane is 99.98%, the tower top material of the pentane separation tower 7 is a light component in the benzene front component, and the content of cyclopentane at the tower top is 2.4%. The components at the bottom of the stabilizer 6 enter an aromatic pre-distillation tower 8, and the BT fraction containing benzene and toluene at the top of the aromatic pre-distillation tower 8 enters an extractive distillation tower 10; the top discharge of the extractive distillation tower 10 is the extraction solvent oil, the bottom of the extractive distillation tower 10 is the mixed oil rich in aromatic hydrocarbon and extractant, and the mixed oil enters the extractant recovery tower 11 after heat exchange; after the separation by the extractant recovery tower 11, BT and a small amount of alkane are at the top of the extractant recovery tower 11, extractant is at the bottom of the extractant recovery tower 11, the extractant is subjected to heat exchange and then returns to the extraction rectification tower 10, and BT and a small amount of alkane evaporated at the top of the extractant recovery tower 11 enter the benzene refining tower 12; pure benzene is evaporated from the top of the refined benzene tower 12, the content of pure benzene sulfur is 0.4ppm, and toluene and a small amount of benzene and methylcyclohexane are discharged from the tower bottom of the refined benzene tower 12; the material is sent into a toluene tower 13, a small amount of mixture of benzene and methylcyclohexane is evaporated at the top of the toluene tower 13 and recycled to the previous working section, and the tower kettle is a qualified toluene product; the XS fraction at the bottom of the aromatic hydrocarbon pre-distillation column 8 enters a xylene distillation column 9, the C5 fraction is extracted from the top of the xylene distillation column 9, the C9 component is extracted from the bottom of the xylene distillation column 9, and a xylene product is extracted from the side line of the column.

Example 3:

filtering the raw material III, feeding the filtered raw material III into a de-weighting tower 2 through a buffer tank 1, removing heavy components with more than nine carbon atoms in the unit, pyrolyzing dicyclopentadiene to produce cyclopentadiene, separating by distillation to obtain a benzene front component I with the temperature of less than 80 ℃ at the top of the de-weighting tower 2, and separating a heavy component II with the temperature of more than or equal to 80 ℃ from a side line of the tower; the benzene front component I and the heavy component II respectively enter a hydrofining unit for reaction. The hydrogenation part adopts a low-temperature low-pressure high-space velocity three-stage hydrofining process, the separated benzene front component I is mixed with hydrogen and then enters a first-stage hydrogenation reactor 3 from top to bottom, the first-stage hydrogenation is a Ni-S reduction catalyst, and the reaction conditions are that the temperature is 30 ℃, the pressure is 3.0MPa and the space velocity is 1.0h^-1Reacting hydrogen and oil in a volume ratio of 600:1, and hydrogenating diolefin in a saturated benzene front component I to generate cyclopentene and cyclopentane; after hydrogenation, mixing the benzene front component I, the heavy component II and hydrogenThe heat exchanger exchanges heat, and then the mixture enters a second-stage hydrogenation reactor 4 from top to bottom, the second-stage hydrogenation reaction is sulfuration state Ni-Mo, the reaction condition is that the temperature is 170 ℃, the pressure is 3.0MPa, and the airspeed is 1.0h^-1Hydrogenation is carried out on the hydrogen-oil volume ratio of 600: 1; saturated first-stage hydrogenation of residual unsaturated olefin; the components after the second-stage hydrogenation are mixed with hydrogen, then heat exchange is carried out through a heat exchanger, the mixture enters a heating furnace for heating, and then the mixture enters a third-stage hydrogenation reactor 5 from top to bottom for desulfurization, denitrification and refining, and sulfur and nitrogen impurities in the mixture are removed through hydrogenation; the Co-Mo catalyst for three-stage hydrogenation reaction has the reaction temperature of 280 ℃, the pressure of 3.0MPa and the space velocity of 1.0h^-1Under the condition that the volume ratio of hydrogen to oil is 600:1, removing sulfur and nitrogen impurities in the oil by hydrogenation; h-containing produced by hydrogenation₂S gas and benzene front components are separated from the top of the stabilizer 6, and heavy components at the bottom of the stabilizer 6 are sent to an aromatic pre-distillation tower 8. And (3) introducing an outlet material at the top of the stabilizing tower 6 into a cyclopentane separation tower 7, wherein the temperature of a tower kettle of the cyclopentane separation tower 7 is 72 ℃, the temperature of the top of the cyclopentane separation tower is 64 ℃, the system pressure is 0.08MPa, the reflux ratio is 2.0, the tower kettle material of the pentane separation tower 7 is a cyclopentane pure product, the content of cyclopentane is 99.98%, the tower top material of the pentane separation tower 7 is a light component in the benzene front component, and the content of cyclopentane at the top of the pentane separation tower 7 is 2.3%. The components at the bottom of the stabilizer 6 enter an aromatic pre-distillation tower 8, and the BT fraction containing benzene and toluene at the top of the aromatic pre-distillation tower 8 enters an extractive distillation tower 10; the top discharge of the extractive distillation tower 10 is the extraction solvent oil, the bottom of the extractive distillation tower 10 is the mixed oil rich in aromatic hydrocarbon and extractant, and the mixed oil enters the extractant recovery tower 11 after heat exchange; after the separation by the extractant recovery tower 11, BT and a small amount of alkane are at the top of the extractant recovery tower 11, extractant is at the bottom of the extractant recovery tower 11, the extractant is subjected to heat exchange and then returns to the extraction rectification tower 10, and BT and a small amount of alkane evaporated at the top of the extractant recovery tower 11 enter the benzene refining tower 12; pure benzene is evaporated from the top of the refined benzene tower 12, the content of pure benzene sulfur is 0.2ppm, and toluene and a small amount of benzene and methylcyclohexane are discharged from the tower bottom of the refined benzene tower 12; the material is sent into a toluene tower 13, a small amount of mixture of benzene and methylcyclohexane is evaporated at the top of the toluene tower 13 and recycled to the previous working section, and the tower kettle is a qualified toluene product; the XS fraction at the bottom of the aromatic hydrocarbon pre-distillation column 8 enters a xylene distillation column 9, the C5 fraction is extracted from the top of the xylene distillation column 9, and the C5 fraction is extracted from the bottom of the xylene distillation column 9C9 components are discharged, and a xylene product is taken out from the side line of the tower.

TABLE 2 product Properties

Item	Raw material one	Raw material II	Raw material III
				Purity of cyclopentane,% of	99.99	99.98	99.98
Sulfur content in refined benzene, ppm	0.3	0.4	0.2
				Saturation ratio of aromatic hydrocarbons,%	0.3	0.2	0.3

It can be seen from the above 3 examples that after raw material pretreatment, hydrorefining, cyclopentane distillation refining, aromatic hydrocarbon separation and refining, the purity of cyclopentane is greater than 99.9%, the sulfur content of refined benzene is less than 0.5ppm, and the product can reach the quality requirements of national standards for petroleum benzene, petroleum toluene, and petroleum mixed xylene. After the crude benzene containing dicyclopentadiene is treated by the process, the product has the highest added value and the process benefit is maximized.