A process for the production of n-hexane

Abstract

The present application belongs to the field of oil refining and chemical industry, and discloses a method for producing n-hexane. The method adopts a light naphtha normalization reaction matched with isoparaffin cycle process to produce n-hexane. The isoparaffin cycle part is to separate isopentane and isohexane in the light naphtha raw material and reaction product by distillation for normalization reaction, and n-hexane in the light naphtha raw material and reaction product is taken as the product. The normalization reaction part adopts a gas phase or a hydrogenation reaction process mainly in gas phase to mix isopentane and isohexane with hydrogen for normalization reaction. The light naphtha normalization reaction matched with isoparaffin cycle process has high normalization reaction efficiency and can maximize the production of n-hexane.

Description

Technical Field

[0001] This invention belongs to the fields of oil refining and chemical engineering, and specifically relates to a method for producing n-hexane. Background Technology

[0002] Naphtha is an important raw material for the production of aromatics and olefins in the oil refining and chemical industries, and it is also one of the blending components of finished gasoline. Generally speaking, the naphtha fraction from its initial boiling point to 80°C is called light naphtha. Light naphtha is mainly used for gasoline blending and the production of olefin products.

[0003] Light naphtha in refineries mainly comes from straight-run light naphtha, hydrocracked light naphtha, reformed pentane oil, and reformed residue oil. Because these light naphthas have low octane ratings (RON), they typically lower the average octane rating in the gasoline blending pool when used as components in finished gasoline products. In an environment of overcapacity in crude oil processing and reductions in finished gasoline production, light naphtha is finding it increasingly difficult to enter the gasoline blending pool.

[0004] Analyzing the price trends of n-pentane and n-hexane over the years, their market prices have been better than those of light naphtha and refined gasoline.

[0005] Under the same operating conditions, the higher the n-alkane content in naphtha, especially light naphtha, the higher the yield of ethylene and butadiene in the cracking products. Studies have shown that naphtha with a n-alkane mass percentage greater than 98.2%, when used as a feedstock for ethylene cracking, increases gas yield from 85.8% to 96.1%, ethylene yield from 31.4% to 47.2%, and the total yield of ethylene, propylene, and butadiene trienes from 52.1% to 65.9% under industrial operating conditions compared to naphtha feedstock.

[0006] Straight-run light naphtha contains more than 40% isoalkanes; reformed pentane oil contains more than 70% isoalkanes; hydrocracking light naphtha and reformed raffinate oil contain more than 80% isoalkanes.

[0007] Therefore, there is an urgent need to propose a new method for producing n-hexane. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for producing n-hexane. The method proposed in this invention employs a light naphtha n-alkanes reaction coupled with an isoalkane recycling process to produce n-hexane. The light naphtha n-alkanes reaction utilizes a gas-phase or predominantly gas-phase hydrocatalytic method, which significantly increases the proportion of n-alkanes in the light naphtha, thus facilitating n-hexane production.

[0009] To achieve the above objectives, the present invention provides a method for producing n-hexane, the method comprising the following steps:

[0010] S1: Light naphtha feedstock is sent to the depentanizer after heat exchange with the bottom product of the depentanizer, to obtain the top product and bottom product of the depentanizer.

[0011] S2: A portion of the bottom material of the depentane tower is sent to the deweighting column after being heat-exchanged with the light naphtha feedstock and the bottom product of the deweighting column as the bottom product of the depentane tower, so as to obtain the hexane fraction, the liquid phase product at the top of the deweighting column, and the bottom material of the deweighting column.

[0012] S3: The hexane fraction, the liquid product at the top of the de-hexane column, is sent to the isohexane column after heat exchange with the product at the bottom of the isohexane column to obtain the isohexane fraction, the liquid product at the top of the isohexane column, and the n-hexane fraction, the product at the bottom of the isohexane column.

[0013] S4: The isohexane-rich product from the top liquid phase of the isohexane removal column is mixed with hydrogen to obtain a mixture; the mixture is heated and then subjected to an ortho-reaction to obtain an ortho-reaction product; before the heating treatment, the mixture and the ortho-reaction product are subjected to heat exchange treatment.

[0014] S5: The ortho-configuration reaction product is cooled and separated into a gaseous product and a liquid product; the gaseous product is sent downstream for processing or pressurized and recycled as hydrogen for the ortho-configuration reaction; the liquid product is sent to the stabilizer after heat exchange with the bottom product of the stabilizer, resulting in a gaseous product at the top of the stabilizer, a liquid product at the top of the stabilizer, and the bottom product of the stabilizer; the bottom product of the stabilizer is sent to the depentanizer after heat exchange with the liquid product.

[0015] The technical solution of the present invention has the following beneficial effects:

[0016] (1) The method proposed in this invention employs a light naphtha ortho-alkanes reaction coupled with an isoparaffin recycling process. The light naphtha ortho-alkanes reaction utilizes a gas-phase or predominantly gas-phase hydrocatalytic method, which significantly increases the proportion of n-alkanes in the light naphtha, thus benefiting the production of n-hexane. The n-hexane produced by this invention can be sent to an olefins unit as feedstock, greatly improving the yield of ethylene and trienes and the conversion rate of the cracking reaction. It can also be sold directly as a product.

[0017] (2) The method for producing n-hexane by the light naphtha n-aromaization reaction and the isoparaffin recycling process proposed in this invention has a low hydrogen-to-oil molar ratio, a short process, a small equipment footprint, and low operating costs.

[0018] (3) The light naphtha ortho-conversion method proposed in this invention adopts a gas-phase or gas-phase-based hydrogen catalysis method and a downward reactor; the downward reactor is equipped with a feed distributor at the inlet and an outlet collector at the bottom, resulting in high ortho-conversion reaction efficiency.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0021] Figure 1 A schematic diagram of the process flow for a method of producing n-hexane provided in Embodiment 1 of the present invention is shown.

[0022] The annotations in the attached figures are explained as follows:

[0023] Isohexane removal column: 502—Hexane-rich fraction, the side stream product of the n-pentane removal column after heat exchange in the third heat exchanger; 503—Isohexane-rich liquid product, the top liquid product, of the isohexane removal column; 504—Gas product, the top gas product, of the isohexane removal column; 505—Bottom product, of the isohexane removal column; 506—Bottom product, the bottom product, of the isohexane removal column after heat exchange in the third heat exchanger; 507—Bottom product, the bottom product, of the isohexane removal column after cooling in the second bottom cooler; 551—Isohexane removal column; 552—Third heat exchanger; 553—Third cooler; 554—Third gas-liquid separator; 555—Third heater; 556—Second bottom cooler.

[0024] Depentanizer: 702—Light naphtha feedstock after heat exchange in the seventh heat exchanger, 703—Pentane fraction, liquid product at the top of the depentanizer, 704—Gas product at the top of the depentanizer, 705—Bottom product of the depentanizer, 706—Bottom product of the depentanizer after heat exchange in the seventh heat exchanger, 751—Depentanizer, 752—Seventh heat exchanger, 753—Seventh cooler, 754—Seventh gas-liquid separator, 755—Seventh heater;

[0025] De-weighting column: 802—Bottom product of the de-pentane column after heat exchange in the eighth heat exchanger, 803—Hexane fraction, liquid product at the top of the de-weighting column, 804—Gas product at the top of the de-weighting column, 805—Bottom product of the de-weighting column, 851—De-weighting column, 852—Eighth heat exchanger, 853—Eighth cooler, 854—Eighth gas-liquid separator, 855—Eighth heater, 856—Fourth bottom cooler;

[0026] Normalization reaction: 1—Feed, 2—Hydrogen gas for normalization reaction, 3—Mixture, 4—Mixture after heat exchange in the fourth heat exchanger, 5—Mixture after heating in the fourth heater, 6—Product of normalization reaction, 7—Product of normalization reaction after heat exchange in the fourth heat exchanger, 8—Product of normalization reaction after air cooler, 9—Product of normalization reaction after cooling in the fourth cooler, 10—Liquid phase product, 11—Liquid phase product after heat exchange in the fifth heat exchanger, 12—Bottom product of stabilizer column, 13—Passage, 14—Stabilizer column 15—Top liquid product of the stabilizer column; 16—Top gaseous product of the stabilizer column; 101—Ortho-structure reactor; 102—Fourth heat exchanger; 103—Fourth heater; 104—Air cooler; 105—Fourth cooler; 106—Fifth gas-liquid separator; 107—Stabilizer column; 108—Fifth heat exchanger; 109—Fifth cooler; 110—Fifth heater; 111—Fourth gas-liquid separator; 112—Compressor; 201—Feed distributor; 202—Catalyst bed; 203—Outlet collector. Detailed Implementation

[0027] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] This invention provides a method for producing n-hexane, the method comprising the following steps:

[0029] S1: Light naphtha feedstock is sent to the depentanizer after heat exchange with the bottom product of the depentanizer, to obtain the top product and bottom product of the depentanizer.

[0030] S2: A portion of the bottom material of the depentane tower is sent to the deweighting column after being heat-exchanged with the light naphtha feedstock and the bottom product of the deweighting column as the bottom product of the depentane tower, so as to obtain the hexane fraction, the liquid phase product at the top of the deweighting column, and the bottom material of the deweighting column.

[0031] S3: The hexane fraction, the liquid product at the top of the de-hexane column, is sent to the isohexane column after heat exchange with the product at the bottom of the isohexane column to obtain the isohexane fraction, the liquid product at the top of the isohexane column, and the n-hexane fraction, the product at the bottom of the isohexane column.

[0032] S4: The isohexane-rich product from the top liquid phase of the isohexane removal column is mixed with hydrogen to obtain a mixture; the mixture is heated and then subjected to an ortho-reaction to obtain an ortho-reaction product; before the heating treatment, the mixture and the ortho-reaction product are subjected to heat exchange treatment.

[0033] S5: The ortho-configuration reaction product is cooled and separated into a gaseous product and a liquid product; the gaseous product is sent to downstream processing or pressurized and recycled as hydrogen for the ortho-configuration reaction; the liquid product is sent to the stabilizer after heat exchange with the bottom product of the stabilizer, to obtain the top gaseous product of the stabilizer, the top liquid product of the stabilizer, and the bottom product of the stabilizer; the bottom product of the stabilizer is sent to the depentanizer after heat exchange with the liquid product.

[0034] The light naphtha feedstock referred to in this invention mainly refers to naphtha fractions from the initial boiling point to 80°C, including straight-run light naphtha, hydrocracked light naphtha, reformed pentane oil, reformed residue oil, etc.

[0035] According to the present invention, preferably, in step S1, the overhead material of the depentanizer is sequentially cooled and separated into gas and liquid phases to obtain the gas phase product from the overhead of the depentanizer and the pentane fraction, which is the liquid phase product from the overhead of the depentanizer.

[0036] According to the present invention, preferably, in step S2:

[0037] Another portion of the bottom material of the depentanizer is heated and refluxed back to the depentanizer for distillation circulation.

[0038] A portion of the bottom material of the de-weighting component tower is heated and then refluxed back to the bottom of the de-weighting component tower for distillation circulation, while the other portion is sent out of the production unit as the bottom product of the de-weighting component tower after heat exchange and cooling. The bottom product of the de-weighting component tower is a C7+ component.

[0039] The material at the top of the deweighting column is sequentially cooled and separated into gas and liquid phases to obtain the gas phase product at the top of the deweighting column and the hexane fraction, which is the liquid phase product at the top of the deweighting column.

[0040] According to the present invention, preferably, in step S3:

[0041] The overhead material of the isohexane stripping tower is sequentially cooled and separated into gas and liquid phases to obtain the overhead gas phase product of the isohexane stripping tower and the overhead liquid phase product of the isohexane stripping tower, which is rich in isohexane.

[0042] A portion of the bottom material from the isohexane stripper is heated and refluxed back to the bottom of the isohexane stripper for distillation circulation, while the other portion, as the bottom product of the isohexane stripper, is sent out of the production unit after heat exchange and cooling.

[0043] According to the present invention, preferably, in step S4:

[0044] The orthoconfiguration reaction is carried out in an orthoconfiguration reactor;

[0045] The orthomorphization reactor is a gas-phase orthomorphization reactor or a gas-phase-dominant orthomorphization reactor.

[0046] The orthomorphic reactor is a downward-flowing reactor, which is provided with a feed inlet, a feed distributor, a catalyst bed and an outlet collector from top to bottom.

[0047] In this invention, "gas-phase-dominant ortho-catalytic reactor" refers to a hydrogenation catalytic method in which the reaction occurring in the reactor is mainly gas-solid or mainly gas-liquid-solid.

[0048] According to the present invention, preferably, after the mixture is heated, it enters the ortho-configuration reactor through the feed inlet, passes through the feed distributor, and is fed into the catalyst bed for ortho-configuration reaction to obtain ortho-configuration reaction products, which are then discharged from the bottom of the ortho-configuration reactor through the outlet collector.

[0049] The ortho-configuration reaction described in this invention is a gas-solid or gas-liquid-solid multiphase catalytic reaction. The resistance to the ortho-configuration reaction comes from three aspects: the mass transfer and diffusion process of light naphtha into the catalyst active sites of the catalyst bed, the diffusion process of hydrogen from the catalyst surface into the catalyst active sites, and the ortho-configuration reaction process itself. The intrinsic activity of the ortho-configuration reaction process is determined by the catalyst itself; however, to increase the catalytic reaction rate, it is necessary to increase the rate of the rate-controlling step. On the one hand, a highly active ortho-configuration catalyst with multiple active sites, high specific surface area, and high stability can be used; on the other hand, specialized internals can be used to improve the homogeneity of gas-liquid phase mixing. For example, after passing through a feed distributor, hydrogen is uniformly distributed in the light naphtha bulk stream, which can effectively improve the mass transfer coefficient and thus accelerate the reaction rate.

[0050] In this invention, the catalyst in the catalyst bed is a catalyst well known to those skilled in the art that is suitable for the normalization reaction, and the composition, particle shape, and size of the catalyst can satisfy the normalization reaction conditions proposed in this invention.

[0051] According to the present invention, preferably, in step S4, in order to accommodate different processing scales, and considering the current equipment processing level and the actual situation of the engineering construction project, the number of ortho-configuration reactors is 1 to 8, preferably 1 to 4, and more preferably 1 to 2; when the number of ortho-configuration reactors is greater than or equal to 2, the ortho-configuration reactors are arranged in series and / or in parallel, preferably in a symmetrical parallel arrangement.

[0052] According to the present invention, preferably, in step S4, the molar ratio of hydrogen gas used in the ortho-configuration reaction to isopentane-rich product from the top liquid phase of the deisopentane tower is 0.1:99.9 to 90:10, more preferably 5:95 to 80:20, and even more preferably 5:95 to 67:33.

[0053] According to the present invention, preferably, in step S4, the conditions for the ortho-configuration reaction include: a reaction temperature of 150–200°C, a pressure of 3–3.6 MPaG, and a weight hourly space velocity of 0.3–50 h⁻¹. -1 More preferably, the conditions for the ortho-configuration reaction include: a reaction temperature of 120–250°C, a pressure of 2.0–4.0 MPaG, and a weight hourly space velocity of 1–10 h⁻¹. -1 More preferably, the conditions for the ortho-configuration reaction include: a reaction temperature of 150–250°C, a pressure of 2.0–4.0 MPaG, and a weight hourly space velocity of 1–2 h⁻¹. -1 .

[0054] According to the present invention, preferably, in step S5:

[0055] The cooling method includes feeding the orthoformation reaction product into an air cooler and / or a cooler for cooling;

[0056] The material at the top of the stabilizer is sequentially cooled and separated into gas and liquid phases to obtain the gaseous product and liquid product at the top of the stabilizer. The gaseous product is sent out of the stabilizer for downstream processing, and a portion of the liquid product is refluxed back to the stabilizer for distillation circulation, while the other portion is sent out as the liquid product at the top of the stabilizer for downstream processing.

[0057] A portion of the bottom material of the stabilizer is heated and refluxed back to the bottom of the stabilizer for distillation circulation, while the other portion is sent to the depentanizer as the bottom product of the stabilizer after heat exchange with the liquid product.

[0058] The liquid phase product at the top of the stabilizer column includes C2 to C4 components;

[0059] The bottom product of the stabilization column is n-formed light naphtha rich in C5-C6 n-alkanes.

[0060] The present invention will be further illustrated by the following examples.

[0061] Example 1

[0062] This embodiment provides a method for processing n-hexane, and the process flow diagram is shown below. Figure 1 As shown, the method includes the following steps:

[0063] S1: Light naphtha feedstock 301 and the bottom product (liquid phase) 705 of the depentanizer are sent to the depentanizer 751 after heat exchange in the seventh heat exchanger 752 to obtain the top material and bottom material of the depentanizer.

[0064] The overhead material of the depentanizer is sequentially cooled and separated by the seventh cooler 753 and the seventh gas-liquid separator 754 to obtain the overhead gas product 704 of the depentanizer and the overhead liquid product pentane fraction 703 of the depentanizer (a portion of which is refluxed back to the depentanizer 751 for distillation circulation).

[0065] The light naphtha feedstock 301 is straight-run light naphtha.

[0066] S2: A portion of the bottom material of the depentanizer is heated and refluxed to the bottom of the depentanizer 751 for distillation circulation. The other portion, as the bottom product 705 of the depentanizer, is sent to the deweighting column 851 after heat exchange with the light naphtha feedstock 301 and the bottom product 805 of the deweighting column through the seventh heat exchanger 752 and the eighth heat exchanger 852, respectively, to obtain the bottom material of the deweighting column and the top material of the deweighting column.

[0067] The material at the top of the deweighting column is sequentially cooled and separated by the eighth cooler 853 and the eighth gas-liquid separator 854 to obtain the gas phase product 804 at the top of the deweighting column and the hexane fraction 803 at the top of the deweighting column (a portion of which is refluxed back to the deweighting column 851 for distillation circulation).

[0068] A portion of the bottom material from the de-weighting column is heated by the eighth heater 855 and then refluxed to the bottom of the de-weighting column 851 for distillation circulation; the other portion is used as the bottom product 805 of the de-weighting column to exchange heat with the bottom product 706 of the depentane de-heating column after heat exchange in the seventh heat exchanger, and then cooled by the fourth bottom cooler 856 before being sent out of the production unit.

[0069] The bottom product 805 of the de-recombined component tower is a C7+ heavy component;

[0070] S3: The hexane fraction 803, the liquid product at the top of the de-hexane column, and the isohexane product 505, the product at the bottom of the de-hexane column, are sent to the isohexane column 551 after heat exchange with the third heat exchanger 552 to obtain the top material and the bottom material of the de-hexane column.

[0071] The overhead material of the isohexane stripper is sequentially cooled and separated by the third cooler 553 and the third gas-liquid separator 554 to obtain the overhead gas product 504 and the overhead liquid product rich in isohexane 503 (a portion of which is refluxed to the isohexane stripper 551 for distillation circulation).

[0072] A portion of the bottom material from the isohexane stripper is heated by the third heater 555 and then refluxed to the bottom of the isohexane stripper 551 for distillation circulation; the other portion, as the bottom product (liquid phase) 505 of the isohexane stripper, exchanges heat with the hexane fraction 803, the liquid phase product at the top of the debinding fraction tower, and is then sent out of the production unit via the second bottom cooler 556; the bottom product 505 of the isohexane stripper is n-hexane.

[0073] S4: The isohexane-rich 503, the liquid product from the top of the isohexane removal tower, is mixed with hydrogen 2 for the ortho-reaction as feed 1 to obtain mixture 3; after being heated by the fourth heater 103, mixture 3 enters the ortho-reaction reactor 101 through the feed inlet, passes through the feed distributor 201, and is fed into the catalyst bed 202 for ortho-reaction to obtain ortho-reaction product 6, which is then discharged from the bottom of the ortho-reaction reactor 101 through the outlet collector 203.

[0074] Before the heating process, the mixture 3 and the ortho-formation reaction product 6 are subjected to heat exchange treatment via the fourth heat exchanger 102;

[0075] The molar ratio (hydrogen-to-oil ratio) of hydrogen 2 used in the ortho-configuration reaction to isohexane 503, the liquid product from the top of the deisohexane tower, is 1.5.

[0076] The conditions for the ortho-configuration reaction include: a reaction temperature of 150–200 °C, a pressure of 3–3.6 MPaG, and a weight hourly space velocity of 1.5 h⁻¹. -1 .

[0077] S5: The ortho-configuration reaction product 6 is sequentially cooled and separated into gas and liquid phases by air cooler 104, fourth cooler 105 and fifth gas-liquid separator 106 to obtain gas phase product 16 and liquid phase product 10; the gas phase product 16 is sent to downstream processing; the liquid phase product 10 and the bottom product 12 of the stabilizer are sent to stabilizer 107 after heat exchange with fifth heat exchanger 108 to obtain stabilizer top material and stabilizer bottom material.

[0078] The material at the top of the stabilizer tower is cooled and separated into gas and liquid phases by passing it through the fifth cooler 109 and the fourth gas-liquid separator 111 to obtain the gaseous product 15 and the liquid product 14 at the top of the stabilizer tower. The gaseous product 15 is sent out of the stabilizer tower 107 for downstream processing, and a portion of the liquid product 14 is refluxed back to the stabilizer tower for distillation circulation, while the other portion is sent out as the liquid product 14 at the top of the stabilizer tower for downstream processing.

[0079] A portion of the bottom material of the stabilizer is refluxed to the bottom of the stabilizer 107 via the fifth heater 110 for distillation circulation; the other portion is sent to the depentanizer 751 for component separation after heat exchange with the liquid product 10 as the bottom product 12 of the stabilizer.

[0080] The liquid product 14 at the top of the stabilizer column is a C2 to C4 component;

[0081] The bottom product 12 of the stabilizer column is n-formed light naphtha rich in C6 n-alkanes.

[0082] The composition of the n-structured light naphtha (for feed) and straight-run light naphtha (for feedstock) obtained by the method of this embodiment were compared, and the results are shown in Table 1. As can be seen from Table 1, the yield of n-hexane in the n-structured light naphtha obtained by the method of this embodiment is significantly increased.

[0083] Table 1 Summary of the operation of the production method in Example 1

[0084]

[0085] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for producing n-hexane, characterized in that, The method includes the following steps: S1: Light naphtha feedstock is sent to the depentanizer after heat exchange with the bottom product of the depentanizer, to obtain the top product and bottom product of the depentanizer. S2: A portion of the bottom material of the depentane tower is sent to the deweighting column after being heat-exchanged with the light naphtha feedstock and the bottom product of the deweighting column as the bottom product of the depentane tower, so as to obtain the hexane fraction, the liquid phase product at the top of the deweighting column, and the bottom material of the deweighting column. S3: The hexane fraction, the liquid product at the top of the de-hexane column, is sent to the isohexane column after heat exchange with the product at the bottom of the isohexane column to obtain the isohexane fraction, the liquid product at the top of the isohexane column, and the n-hexane fraction, the product at the bottom of the isohexane column. S4: The isohexane-rich product from the top liquid phase of the isohexane removal column is mixed with hydrogen to obtain a mixture; the mixture is heated and then subjected to an ortho-reaction to obtain an ortho-reaction product; before the heating treatment, the mixture and the ortho-reaction product are subjected to heat exchange treatment. The orthoconfiguration reaction is carried out in an orthoconfiguration reactor; The orthomorphic reactor is a gas-phase-dominant orthomorphic reactor; The ortho-configuration reactor is a downward-flowing reactor, which is provided with an inlet, a feed distributor, a catalyst bed, and an outlet collector from top to bottom. The mixture is heated and then enters the ortho-configuration reactor through the inlet. After passing through the feed distributor, it is fed into the catalyst bed to carry out the ortho-configuration reaction, and the ortho-configuration reaction product is obtained and discharged from the bottom of the ortho-configuration reactor through the outlet collector. The molar ratio of hydrogen gas used in the ortho-configuration reaction to isohexane-rich product from the overhead liquid phase of the isohexane removal column is 0.1:99.9 to 90:

10. The conditions for the ortho-configuration reaction include: a reaction temperature of 150–200 °C, a pressure of 3–3.6 MPaG, and a weight hourly space velocity of 0.3–50 h⁻¹. -1 ; S5: The product of the normalization reaction is cooled and separated into a gaseous product and a liquid product; the gaseous product is sent to downstream processing or pressurized and recycled as hydrogen for the normalization reaction; the liquid product is sent to the stabilizer after heat exchange with the bottom product of the stabilizer, to obtain the gaseous product at the top of the stabilizer, the liquid product at the top of the stabilizer, and the bottom product of the stabilizer; the bottom product of the stabilizer is sent to the depentanizer after heat exchange with the liquid product. The bottom product of the stabilization column is n-formed light naphtha rich in C5-C6 n-alkanes.

2. The method for producing n-hexane according to claim 1, wherein, In step S1, the overhead material of the depentanizer is sequentially cooled and separated into gas and liquid phases to obtain the gas phase product from the overhead of the depentanizer and the pentane fraction, which is the liquid phase product from the overhead of the depentanizer.

3. The method for producing n-hexane according to claim 1, wherein, In step S2: Another portion of the bottom material of the depentanizer is heated and refluxed back to the depentanizer for distillation circulation. A portion of the bottom material of the de-weighting component tower is heated and then refluxed back to the bottom of the de-weighting component tower for distillation circulation, while the other portion is sent out of the production unit as the bottom product of the de-weighting component tower after heat exchange and cooling. The bottom product of the de-weighting component tower is a C7+ component. The material at the top of the deweighting column is sequentially cooled and separated into gas and liquid phases to obtain the gas phase product at the top of the deweighting column and the hexane fraction, which is the liquid phase product at the top of the deweighting column.

4. The method for producing n-hexane according to claim 1, wherein, In step S3: The overhead material of the isohexane stripping tower is sequentially cooled and separated into gas and liquid phases to obtain the overhead gas phase product of the isohexane stripping tower and the overhead liquid phase product of the isohexane stripping tower, which is rich in isohexane. A portion of the bottom material from the isohexane stripper is heated and refluxed back to the bottom of the isohexane stripper for distillation circulation, while the other portion, as the bottom product of the isohexane stripper, is sent out of the production unit after heat exchange and cooling.

5. The method for producing n-hexane according to claim 1, wherein, The orthoconfiguration reactor is a gas-phase orthoconfiguration reactor.

6. The method for producing n-hexane according to claim 5, wherein, The number of ortho-configuration reactors is 1 to 8. When the number of ortho-configuration reactors is greater than or equal to 2, the ortho-configuration reactors are arranged in series and / or in parallel.

7. The method for producing n-hexane according to claim 1, wherein, In step S5: The cooling method includes feeding the ortho-configuration reaction product into an air cooler for cooling; The material at the top of the stabilizer is sequentially cooled and separated into gas and liquid phases to obtain the gaseous product and liquid product at the top of the stabilizer. The gaseous product is sent out of the stabilizer for downstream processing, and a portion of the liquid product is refluxed back to the stabilizer for distillation circulation, while the other portion is sent out as the liquid product at the top of the stabilizer for downstream processing. A portion of the bottom material of the stabilizer is heated and refluxed back to the bottom of the stabilizer for distillation circulation, while the other portion is sent to the depentanizer as the bottom product of the stabilizer after heat exchange with the liquid product. The liquid phase product at the top of the stabilizer column includes C2 to C4 components.

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