Linear alkylbenzene production process and linear alkylbenzene production equipment

Abstract

The invention discloses a linear alkylbenzene production process and a linear alkylbenzene production device. The invention adopts a reactive distillation method to carry out an alkylbenzene reaction. The alkylbenzene reaction is an exothermic reaction. The heat released by the reaction can be used as a distillation heat source to achieve full utilization of process energy, thereby reducing production energy consumption. In addition, the heat generated by the alkylation reaction is absorbed by the rising airflow, which can also prevent the temperature of the reaction section from being too high, causing the catalyst to be sintered and then causing the activity to decrease. The catalyst used in the linear alkylbenzene production process of the invention is a solid acid catalyst, which is non-corrosive to the reaction equipment and easy to regenerate and recycle. In the production process, the reaction and distillation occur simultaneously, and the reaction product continuously flows into the linear alkylbenzene separation tower for separation, which is conducive to the alkylation reaction to proceed in the forward direction. In general, the linear alkylbenzene production process of the invention has low energy consumption, low operating difficulty, long catalyst service life, high conversion rate of linear alkylbenzene, and very few reaction by-products.

Description

Technical Field

[0001] The invention relates to the technical field of alkylbenzene production, and in particular to a linear alkylbenzene production process and linear alkylbenzene production equipment. Background Art

[0002] Linear alkylbenzene (LAB) is an important aromatic organic chemical raw material. Linear alkylbenzene (LAB) can be used to produce linear alkylbenzene sulfonic acid (LAS). LAS has now become the main raw material for household and industrial detergents.

[0003] The method of preparing LAB by alkylation of benzene with linear olefins in liquid phase belongs to the traditional Friedel-Crafts type reaction, which mainly uses Lewis acids such as AlCl3, BF3, H2SO4, H3PO4, HF, etc. as catalysts. The HF process is the most widely used in industry, while traditional liquid acid catalysts such as HF and AlCl3 seriously corrode equipment and pollute the environment during the production process, and the product and catalyst are not easy to separate. Because the HF process has many shortcomings and disadvantages, researchers are constantly studying to develop solid acid catalysts that are non-corrosive to reaction equipment and easy to regenerate or recycle. At present, the more mature solid acid process in industrial application is UOP's Detal alkylation process. In the Detal process, olefins and benzene are mixed and flow through a fixed bed reactor containing a solid acid catalyst. The entire reaction is carried out in the liquid phase, and the reactant stream is directly sent to the fractionation part. Compared with the HF acid process, the HF stripping tower, aluminum chloride processor, and the entire HF regeneration part and tail gas treatment part have been eliminated.

[0004] The traditional HF process for producing alkylbenzene requires the use of special alloy materials in the construction of the device, and requires the construction of HF regeneration, stripping, storage systems, acidic water vapor absorption and neutralization systems, which will produce wastes such as tar, calcium fluoride and fluorine-containing aluminum oxide. The environmental protection management and testing investment is large, and the environmental protection cost is high. The Detal process uses a non-corrosive solid acid catalyst, and the entire production device can be made of carbon steel. Compared with the HF acid process, the Detal catalytic reaction conditions are more stringent (the reaction temperature and pressure are high, and the benzene circulation ratio is large), and the energy consumption and material consumption are high, which makes it at a disadvantage in the comparison of the total cost components of the product; the catalyst life of the Detal process is only 24 hours, and there is a defect of rapid deactivation, resulting in a short operating cycle of the catalyst and frequent regeneration. In order to maintain the liquid-solid reaction, a higher operating pressure (3.5MPa) is required, which increases the difficulty of operation and energy consumption. Summary of the invention

[0005] The purpose of the present invention is firstly to provide a linear alkylbenzene production process with low energy consumption, low operation difficulty, long catalyst service life, high linear alkylbenzene conversion rate and very few reaction by-products.

[0006] The present invention also aims to provide a linear alkylbenzene production device with low energy consumption, low operation difficulty, high linear alkylbenzene conversion rate and very few reaction by-products.

[0007] To achieve the above object of the invention, the present invention first provides a linear alkylbenzene production process, comprising:

[0008] Provide linear alkylbenzene production equipment and linear alkylbenzene production raw materials;

[0009] The linear alkylbenzene production raw materials include linear olefins and benzene;

[0010] The linear alkylbenzene production equipment comprises a linear alkylbenzene reaction device and a linear alkylbenzene separation device connected to the linear alkylbenzene reaction system;

[0011] The linear alkylbenzene reaction device comprises a linear alkylbenzene reaction distillation tower, a benzene reflux system and a first reboiler connected to the linear alkylbenzene reaction distillation tower; the linear alkylbenzene reaction distillation tower comprises a first distillation section, a reaction section and a first stripping section arranged in sequence from top to bottom; a solid acid catalyst is arranged in the reaction section;

[0012] The reaction section and / or the first rectifying section are provided with an olefin inlet; the first rectifying section and the first stripping section are both provided with a benzene input port;

[0013] The inlet of the benzene reflux system is connected to the first rectifying section, and the outlet of the benzene reflux system is connected to the first rectifying section and the first stripping section; the first reboiler is connected to the first stripping section;

[0014] During the production process, linear olefins and benzene enter the linear alkylbenzene reaction distillation tower via the olefin inlet and the benzene inlet respectively; part of the reflux benzene collected by the benzene reflux system enters the linear alkylbenzene reaction distillation tower via the first distillation section, and the other part enters the linear alkylbenzene reaction distillation tower via the first stripping section; during the production process, it is also necessary to supplement fresh raw benzene to the linear alkylbenzene reaction distillation tower, and this part of fresh raw benzene enters the linear alkylbenzene reaction distillation tower via the first stripping section.

[0015] Optionally, a benzene output port and a first benzene input port are provided on the first distillation section, a second benzene input port is provided on the first stripping section, and the benzene reflux system includes a first condenser connected to the benzene output port, a first reflux tank connected to the first condenser, and a first reflux pump connected to the first reflux tank, the first benzene input port and the second benzene input port, respectively, and the first reflux pump is used to pump out the liquid benzene collected in the first reflux tank, a part of which is transported to the first benzene input port via a pipeline, and the other part is transported to the second benzene input port via a pipeline.

[0016] Optionally, fresh raw benzene added to the linear alkylbenzene reaction distillation tower during the production process enters the linear alkylbenzene reaction distillation tower via the second benzene input port;

[0017] The linear alkylbenzene production equipment further includes a first heater connected to the second benzene input port to heat fresh raw benzene and reflux benzene input through the second benzene input port.

[0018] Optionally, the linear alkylbenzene separation device comprises a linear alkylbenzene separation tower and a linear alkylbenzene collection and reflux system and a second reboiler connected to the linear alkylbenzene separation tower; the linear alkylbenzene separation tower comprises a second rectifying section and a second stripping section arranged in sequence from top to bottom; the inlet and the outlet of the linear alkylbenzene collection and reflux system are both connected to the second rectifying section, and the second reboiler is connected to the second stripping section;

[0019] The second distillation section is provided with a linear alkylbenzene outlet and a linear alkylbenzene inlet, and the linear alkylbenzene collecting reflux system comprises a second condenser connected to the linear alkylbenzene outlet, a second reflux tank connected to the second condenser, and a second reflux pump respectively connected to the second reflux tank and the linear alkylbenzene inlet.

[0020] Optionally, the linear alkylbenzene collection and reflux system further comprises a heat exchanger disposed between the linear alkylbenzene output port and the second condenser;

[0021] The linear alkylbenzene production equipment further includes a second heater located between the heat exchanger and an olefin input port on the linear alkylbenzene reactive distillation tower.

[0022] Optionally, the number of the olefin inlets is 3 or more; the projection intervals of the 3 or more olefin inlets on the radial cross section of the linear alkylbenzene reactive distillation tower are evenly distributed;

[0023] The linear alkylbenzene reaction distillation tower is cylindrical and has the same diameter in each region, and the ratio of the height to the diameter of the linear alkylbenzene reaction distillation tower is 5-100:1;

[0024] In the linear alkylbenzene reactive distillation tower, the ratio of the heights of the first distillation section, the reaction section and the first stripping section is 0-10:20-50:40-80.

[0025] Optionally, during the production process, the molar ratio of the reflux benzene fed into the linear alkylbenzene reactive distillation tower via the benzene reflux system to the linear olefin fed per unit time is 1-5:1, and the molar ratio of the feed rate of the supplemented fresh raw benzene to the linear olefin fed per unit time is 1-1.1:1;

[0026] The temperature range of the first rectifying section is 80-120°C, and the temperature range of the reaction section and the first stripping section are both 150-300°C;

[0027] During the production process, the pressure in the linear alkylbenzene reaction distillation tower is 0-0.3 MPa(g).

[0028] Optionally, a fixing device for fixing the solid acid catalyst is further provided in the reaction section;

[0029] The solid acid catalyst includes the following components and their mass proportions: molecular sieve 1 / 2-9 / 10, binder 1 / 10-1 / 2; the molecular sieve includes one or more of H-MCM-36, H-MCM-49, H-MCM-56, H-PSH-3, H-SSZ-25, H-ITQ-1, H-ITQ-2, H-ZSM-5, H-ZSM-12, H-ZSM-35, and H-β.

[0030] Specifically, in some embodiments, the linear olefin is mixed with alkanes; the linear alkylbenzene production equipment further includes an alkane separation device connected to the linear alkylbenzene separation device.

[0031] The present invention also provides a linear alkylbenzene production device, comprising: a linear alkylbenzene reaction device and a linear alkylbenzene separation device connected to the linear alkylbenzene reaction system;

[0032] The linear alkylbenzene reaction device comprises a linear alkylbenzene reaction distillation tower and a benzene reflux system and a first reboiler connected to the linear alkylbenzene reaction distillation tower; the linear alkylbenzene reaction distillation tower comprises a first distillation section, a reaction section and a first stripping section arranged in sequence from top to bottom;

[0033] The reaction section and / or the first rectifying section are provided with an olefin inlet; the first rectifying section and the first stripping section are both provided with a benzene input port;

[0034] The inlet of the benzene reflux system is connected to the first distillation section, and the outlet of the benzene reflux system is connected to the first distillation section and the first stripping section; the first reboiler is connected to the first stripping section.

[0035] Beneficial effects of the present invention:

[0036] (1) The present invention adopts reactive distillation to carry out alkylbenzene reaction. Alkylbenzene reaction is an exothermic reaction. The heat released by the reaction can be used as a distillation heat source to fully utilize the process energy, thereby reducing production energy consumption. In addition, the heat generated by the alkylation reaction is absorbed by the rising airflow, which can also prevent the temperature of the reaction section from being too high, causing the catalyst to be sintered and then causing the activity to decrease.

[0037] Preferably, the linear alkylbenzene reactive distillation tower is provided with a plurality of olefin inlets, so that the raw linear olefin can be fed in multiple streams, thereby increasing the instantaneous benzene-olefin ratio of the reaction, thereby increasing the yield of the target product (i.e., linear alkylbenzene), reducing the total benzene-olefin ratio required for the reaction, and reducing production costs.

[0038] (2) The catalyst used in the linear alkylbenzene production process of the present invention is a solid acid catalyst, which is non-corrosive to the reaction equipment and easy to regenerate and recycle. Furthermore, the present invention also selects a solid acid catalyst with simple components, easy preparation, and low production cost. The solid acid catalyst has high olefin conversion rate, high 2-LAB selectivity, and good stability.

[0039] (3) In the linear alkylbenzene production process of the present invention, liquid benzene entering from the top of the linear alkylbenzene reaction distillation tower (i.e., the first distillation section) enters the reaction section and continuously washes the catalyst located in the reaction section, thereby washing away coking materials (such as charcoal, etc.) formed on the surface of the catalyst, thereby preventing the catalyst from being covered by coking materials and causing the activity to decrease, thereby extending the service life of the catalyst.

[0040] (4) In the linear alkylbenzene production process of the present invention, reaction and distillation occur simultaneously, and the reaction product continuously flows into the linear alkylbenzene separation tower for separation, which is conducive to the alkylation reaction proceeding in the forward direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope of the present invention.

[0042] Figure 1 A schematic structural diagram of an embodiment of a linear alkylbenzene production device used in the linear alkylbenzene production process of the present invention;

[0043] Figure 2The present invention is a schematic structural diagram of another embodiment of a linear alkylbenzene production device used in the linear alkylbenzene production process of the present invention.

[0044] Description of main component symbols:

[0045] 10. Linear alkylbenzene reactive distillation tower; 11. First distillation section; 12. Reaction section; 13. First stripping section; 21. First reboiler; 30. Linear alkylbenzene separation tower; 31. Second distillation section; 32. Second stripping section; 22. Second reboiler; 41. First condenser; 42. First reflux tank; 43. First reflux pump; 51. First heater; 52. Second heater; 60. Heat exchanger; 71. Second condenser; 72. Second reflux tank; 73. Second reflux pump; 80. Alkane separation tower; 81. Third distillation section; 82. Third stripping section; 23. Third reboiler; 91. Third condenser; 92. Third reflux tank; 93. Third reflux pump. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0047] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0048] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present invention, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0049] In various embodiments of the present invention, the expression "A or / and B" includes any combination or all combinations of the words listed simultaneously, and may include A, may include B, or may include both A and B.

[0050] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "lateral", "top", "bottom", "inside", "outside" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0051] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0052] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. Unless otherwise specified, all terms used herein (including technical terms and scientific terms) have the same meanings as those generally understood by ordinary technicians in the field to which the various embodiments of the present invention belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present invention.

[0053] See also Figure 1 The present invention provides a linear alkylbenzene production process, comprising:

[0054] Provide linear alkylbenzene production equipment and linear alkylbenzene production raw materials;

[0055] The linear alkylbenzene production raw materials include linear olefins and benzene;

[0056] The linear alkylbenzene production equipment comprises a linear alkylbenzene reaction device and a linear alkylbenzene separation device connected to the linear alkylbenzene reaction system;

[0057] The linear alkylbenzene reaction device comprises a linear alkylbenzene reaction distillation tower 10 and a benzene reflux system and a first reboiler 21 connected to the linear alkylbenzene reaction distillation tower 10; the linear alkylbenzene reaction distillation tower 10 comprises a first distillation section 11, a reaction section 12 and a first stripping section 13 arranged in sequence from top to bottom; a solid acid catalyst is arranged in the reaction section 12; the inlet of the benzene reflux system is connected to the first distillation section 11, and the outlet of the benzene reflux system is connected to the first distillation section 11 and the first stripping section 13; the first reboiler 21 is connected to the first stripping section 13;

[0058] The reaction section 12 and / or the first rectifying section 11 are provided with an olefin inlet; the first rectifying section 11 and the first stripping section 13 are both provided with a benzene input port;

[0059] During the production process, linear olefins and benzene enter the linear alkylbenzene reaction distillation tower 10 via the olefin inlet and the benzene inlet respectively; part of the reflux benzene collected by the benzene reflux system enters the linear alkylbenzene reaction distillation tower 10 via the first distillation section 11, and the other part enters the linear alkylbenzene reaction distillation tower 10 via the first stripping section 13; during the production process, it is also necessary to supplement fresh raw benzene to the linear alkylbenzene reaction distillation tower 10, and this part of fresh raw benzene enters the linear alkylbenzene reaction distillation tower 10 via the first stripping section 13.

[0060] Specifically, the linear alkylbenzene separation device includes a linear alkylbenzene separation tower 30 and a linear alkylbenzene collecting reflux system and a second reboiler 22 connected to the linear alkylbenzene separation tower 30; the linear alkylbenzene separation tower 30 includes a second distillation section 31 and a second stripping section 32 arranged in sequence from top to bottom; the inlet and outlet of the linear alkylbenzene collecting reflux system are both connected to the second distillation section 31, and the second reboiler 22 is connected to the second stripping section 32.

[0061] Specifically, a reaction product feed port is provided on the linear alkylbenzene separation tower 30, a portion of the linear alkylbenzene separation tower 30 located above the reaction product feed port is a second rectification section 31, and a portion located below the reaction product feed port is a second stripping section 32. Obviously, the division method of the second rectification section 31 and the second stripping section 32 is common knowledge in the art.

[0062] Specifically, the working principle of the linear alkylbenzene production equipment of the present invention is:

[0063] Before entering the linear alkylbenzene reaction distillation tower 10, the linear olefin and benzene are both in liquid state. After entering the linear alkylbenzene reaction distillation tower 10, benzene is vaporized into gaseous benzene in the first stripping section 13, and the gaseous benzene evaporates from the bottom of the tower to the top of the tower, that is, the flow path of the gaseous benzene in the tower is from bottom to top. After entering the linear alkylbenzene reaction distillation tower 10, the linear olefin remains in liquid state, that is, the flow path of the linear olefin in the tower is from top to bottom. Therefore, in the linear alkylbenzene reaction distillation tower 10, the linear olefin contacts with the gaseous benzene in reverse direction and undergoes alkylation reaction in the reaction section 12 to generate linear alkylbenzene;

[0064] Preferably, the number of the olefin inlets is 3 or more. Optionally, the projection intervals of the 3 or more olefin inlets on the radial cross section of the linear alkylbenzene reactive distillation tower 10 are evenly distributed;

[0065] Since the linear olefin enters the linear alkylbenzene reaction distillation tower 10 via multiple olefin inlets, that is, the linear olefin enters the linear alkylbenzene reaction distillation tower 10 in multiple streams, and since the concentration ratio of the benzene to olefin mixture per unit cross-sectional area is higher than that of a single stream feed, the instantaneous benzene-olefin ratio of the alkylation reaction can be increased, thereby increasing the selectivity of the target product, so that only a very small amount of by-products (heavy alkylbenzenes) are generated during the reaction, and at the same time, the total benzene-olefin ratio required for the alkylation reaction can be reduced, saving raw material costs;

[0066] In the alkylation reaction, in order to obtain high selectivity of the alkylation reaction, the amount of benzene added is usually excessive. Therefore, in the linear alkylbenzene reaction distillation tower 10, the gaseous benzene that does not participate in the alkylation reaction enters the benzene reflux system from the top of the tower (i.e., the first distillation section 11) to be condensed, collected and refluxed into the linear alkylbenzene reaction distillation tower 10. A part of the reflux benzene enters the linear alkylbenzene reaction distillation tower 10 from the top of the tower (i.e., the first distillation section 11), and the other part enters the linear alkylbenzene reaction distillation tower 10 from the bottom of the tower (i.e., the first stripping section 13); wherein, the reflux benzene entering the linear alkylbenzene reaction distillation tower 10 from the top of the tower (i.e., the first distillation section 11) can absorb the heat of the first distillation section 11, thereby reducing the temperature of the first distillation section 11, and preventing the temperature of the first distillation section 11 from being too high, resulting in the gasification of linear olefins and then volatilization from the linear alkylbenzene reaction distillation tower 10;

[0067] The linear olefin reacts with benzene in the reaction section 12 to generate a reaction product, wherein the reaction product includes linear alkylbenzene and a small amount of heavy alkylbenzene, wherein the linear alkylbenzene is a product obtained by combining a benzene molecule with a linear olefin molecule, and the heavy alkylbenzene is a product obtained by combining a benzene molecule with two or more linear olefin molecules;

[0068] The reaction products (including linear alkylbenzene and heavy alkylbenzene) generated in the reaction section 12 enter the bottom of the tower (i.e., the first stripping section 13) and are introduced into the first reboiler 21 for heating. The vaporized part of the heated reaction products is returned to the linear alkylbenzene reaction distillation tower 10 to provide the required heat for heat transfer and mass transfer in the linear alkylbenzene reaction distillation tower 10. A part of the unvaporized reaction products in the first reboiler 21 is transported to the linear alkylbenzene separation device via a pipeline to separate the linear alkylbenzene from the heavy alkylbenzene.

[0069] In the linear alkylbenzene separation device, the linear alkylbenzene separation tower 30 is used to separate the linear alkylbenzene and heavy alkylbenzene in the reaction product. In the linear alkylbenzene separation tower 30, under the control of temperature and pressure, the linear alkylbenzene is transformed into a gaseous state and enters the linear alkylbenzene collection reflux system from the top of the tower (i.e., the second distillation section 31), and the heavy alkylbenzene is kept in a liquid state and collected at the bottom of the tower (i.e., the second stripping section 32);

[0070] The linear alkylbenzene collecting and reflux system is used to condense and collect the gaseous linear alkylbenzene volatilized from the top of the tower (i.e., the second distillation section 31), and a part of the collected linear alkylbenzene is directly extracted as a product, and the other part is refluxed to the linear alkylbenzene separation tower 30 for secondary purification to further improve the purity of the linear alkylbenzene and remove the heavy alkylbenzene mixed in the linear alkylbenzene to the greatest extent;

[0071] In the linear alkylbenzene separation device, the second reboiler 22 is used to heat the heavy alkylbenzene located at the bottom of the tower (i.e., the second distillation section 32), and the vaporized heavy alkylbenzene after heating is returned to the linear alkylbenzene separation tower 30 to provide the required heat for heat transfer and mass transfer in the linear alkylbenzene separation tower 30; a part of the unvaporized heavy alkylbenzene in the second reboiler 22 can be directly extracted as a product, or can be refluxed to the linear alkylbenzene reaction distillation tower 10 to undergo an alkyl transfer reaction with benzene to generate linear alkylbenzene.

[0072] Taking the alkylation reaction of C8 straight-chain olefins and benzene as an example, the reaction equations of the alkylation reaction, alkylation side reaction and transalkylation reaction are described as follows:

[0073] The reaction formula of alkylation reaction (linear olefin reacts with benzene to form linear alkylbenzene) is:

[0074]

[0075] The reaction formula for the alkylation side reaction (straight-chain olefins react with benzene to form heavy alkylbenzenes) is:

[0076]

[0077] The reaction equation for the transalkylation reaction is:

[0078]

[0079] Specifically, during the alkylbenzene reaction, the liquid benzene entering from the first distillation section 11 can continuously flush the catalyst located in the reaction section 12, thereby inhibiting the occurrence of coking on the catalyst surface, avoiding a reduction in catalyst activity, and extending the service life of the catalyst.

[0080] In the linear alkylbenzene production process of the present invention, alkylation reaction and distillation occur simultaneously, and the reaction product is continuously transferred to the linear alkylbenzene separation tower 30, which is conducive to the reaction proceeding in the forward direction.

[0081] In one embodiment of the present invention, the number of the olefin inlets is 4, wherein 3 olefin inlets are located on the reaction section 12 , and 1 olefin inlet is located on the first distillation section 11 .

[0082] Specifically, the linear alkylbenzene reaction distillation tower 10 is cylindrical and has the same diameter in each region. The ratio of the height to the diameter of the linear alkylbenzene reaction distillation tower 10 is 5-100:1, and more preferably 5-50:1.

[0083] Specifically, in the linear alkylbenzene reactive distillation tower 10, the ratio of the heights of the first distillation section 11, the reaction section 12 and the first stripping section 13 is 0-10:20-50:40-80.

[0084] Specifically, the linear olefin includes one or more of C8 to C24 linear olefins, for example, one or more of C8 linear olefins, C10 linear olefins, C13 linear olefins, C15 linear olefins, C17 linear olefins, C20 linear olefins, C22 linear olefins, and C24 linear olefins.

[0085] Specifically, the first distillation section 11 is provided with a benzene output port and a first benzene input port, the first stripping section 13 is provided with a second benzene input port, the benzene reflux system includes a first condenser 41 connected to the benzene output port, a first reflux tank 42 connected to the first condenser 41, and a first reflux pump 43 connected to the first reflux tank 42, the first benzene input port and the second benzene input port, respectively, the first reflux pump 43 is used to pump out the liquid benzene collected in the first reflux tank 42, a part of which is transported to the first benzene input port via a pipeline, and the other part is transported to the second benzene input port via a pipeline.

[0086] Specifically, the fresh raw benzene added to the linear alkylbenzene reaction distillation tower 10 during the production process enters the linear alkylbenzene reaction distillation tower 10 through the second benzene input port.

[0087] Preferably, the linear alkylbenzene production equipment also includes a first heater 51 connected to the second benzene input port to heat the fresh raw benzene and reflux benzene input through the second benzene input port, so that they have a higher temperature before entering the linear alkylbenzene reaction distillation tower 10, which is beneficial to maintaining the temperature in the linear alkylbenzene reaction distillation tower 10 stable.

[0088] Specifically, the second distillation section 31 is provided with a linear alkylbenzene outlet and a linear alkylbenzene inlet, and the linear alkylbenzene collecting reflux system includes a second condenser 71 connected to the linear alkylbenzene outlet, a second reflux tank 72 connected to the second condenser 71, and a second reflux pump 73 connected to the second reflux tank 72 and the linear alkylbenzene inlet, respectively. The second reflux pump 73 is used to pump out the liquid linear alkylbenzene collected in the second reflux tank 72, a part of which is extracted as a product, and the other part enters the linear alkylbenzene separation tower 30 through the linear alkylbenzene inlet for secondary purification to improve the purity of linear alkylbenzene.

[0089] Optionally, the linear alkylbenzene collection and reflux system also includes a heat exchanger 60 disposed between the linear alkylbenzene output port and the second condenser 71, wherein the heat exchanger 60 is used to perform heat exchange between gaseous linear alkylbenzene and linear olefins used as production raw materials, and to cool the gaseous linear alkylbenzene using the linear olefins, and to heat the linear olefins using the gaseous linear alkylbenzene to increase the temperature of the linear olefins.

[0090] Preferably, the linear alkylbenzene production equipment further comprises a second heater 52 located between the heat exchanger 60 and the olefin input port on the linear alkylbenzene reaction distillation tower 10, and the second heater 52 is used to further heat the linear olefin to keep the temperature in the linear alkylbenzene reaction distillation tower 10 stable.

[0091] Specifically, during the production process, the molar ratio of the reflux benzene input into the linear alkylbenzene reaction distillation tower 10 via the benzene reflux system to the linear olefin fed per unit time is 1-5:1, and the molar ratio of the feed rate of the supplementary fresh raw benzene to the linear olefin fed per unit time is 1-1.1:1.

[0092] In general, in the entire alkylbenzene production process, the ratio of the total amount of benzene added as a production raw material into the linear alkylbenzene reaction distillation tower 10 to the total amount of linear olefins is 1-1.1:1.

[0093] By using excess benzene to react with linear olefins, a high conversion rate and high selectivity of the alkylation reaction can be achieved, the yield of linear alkylbenzenes can be increased, and the yield of heavy alkylbenzenes can be reduced.

[0094] Specifically, in the linear alkylbenzene reactive distillation tower 10, the temperature range of the first distillation section 11 is 80-120°C, and the temperature ranges of the reaction section 12 and the first stripping section 13 are both 150-300°C.

[0095] Specifically, during the production process, the pressure in the linear alkylbenzene reaction distillation tower 10 is 0-0.3 MPa (g). Specifically, the pressure in the linear alkylbenzene reaction distillation tower 10 gradually increases from the top to the bottom.

[0096] Specifically, in the reaction section 12, the total mass space velocity of the linear olefin and benzene is 1-5h -1 , the mass space velocity of straight chain olefins is 0.2-0.3h -1 .

[0097] Specifically, the mass ratio of the portion of the reaction product heated by the first reboiler 21 that refluxes into the linear alkylbenzene reaction distillation tower 10 to the portion that flows into the alkylbenzene separation tower is 3-5:1.

[0098] Specifically, in the linear alkylbenzene separation tower 30, both the second rectifying section 31 and the second stripping section 32 are provided with plates, the number of plates in the second rectifying section 31 is 1-40, and the number of plates in the second stripping section 32 is 1-40.

[0099] Specifically, in the linear alkylbenzene separation tower 30, the temperature of the second rectifying section 31 is 120-250°C, and the temperature of the second stripping section 32 is 200-300°C.

[0100] Specifically, the pressure in the linear alkylbenzene separation tower 30 is 0-200 KPa. Specifically, the pressure in the linear alkylbenzene separation tower 30 gradually increases from the top to the bottom.

[0101] Specifically, the mass ratio of the linear alkylbenzene collected by the linear alkylbenzene collection and reflux system and refluxed into the linear alkylbenzene separation tower 30 to the mass ratio of the linear alkylbenzene recovered as a product is greater than 0.3.

[0102] Specifically, the first rectifying section 11, the first stripping section 13, the second rectifying section 31, and the second stripping section 32 may be plate tower sections or packed tower sections. The plate tower sections may be provided with any applicable tower plates, and the packed tower sections may be filled with random packing or regular packing.

[0103] Specifically, the reaction section 12 is further provided with a fixing device for fixing the solid acid catalyst, and the reaction section 12 is not provided with a tower plate or a filler.

[0104] Specifically, the solid acid catalyst includes the following components and their mass proportions: molecular sieve 1 / 2-9 / 10, binder 1 / 10-1 / 2.

[0105] Specifically, the molecular sieve includes one or more of H-MCM-36, H-MCM-49, H-MCM-56, H-PSH-3, H-SSZ-25, H-ITQ-1, H-ITQ-2, H-ZSM-5, H-ZSM-12, H-ZSM-35, and H-β.

[0106] Optionally, the molecular sieve includes the following components and their mass parts: 20-100 parts of H-MCM-36, 20-100 parts of H-MCM-49, 20-100 parts of H-MCM-56, 20-100 parts of H-PSH-3, 20-100 parts of H-SSZ-25, 20-100 parts of H-ITQ-1, 20-100 parts of H-ITQ-2, 20-100 parts of H-ZSM-5, 20-100 parts of H-ZSM-12, 20-100 parts of H-ZSM-35, and 20-100 parts of H-β zeolite.

[0107] Preferably, the molecular sieve includes the following components and their mass parts: 20-50 parts of H-MCM-36, 20-50 parts of H-MCM-49, 20-50 parts of H-MCM-56, 20-50 parts of H-PSH-3, 20-50 parts of H-SSZ-25, 20-50 parts of H-ITQ-1, 20-50 parts of H-ITQ-2, 20-50 parts of H-ZSM-5, 20-50 parts of H-ZSM-12, 20-50 parts of H-ZSM-35, and 20-50 parts of H-β zeolite.

[0108] Specifically, the binder includes one or more of Al2O3, SiO2, TiO4, kaolin, montmorillonite, and bentonite.

[0109] Optionally, the preparation method of the solid acid catalyst comprises:

[0110] Add a binder to the catalyst (molecular sieve) and mix evenly with 0.5-0.6 mol / L HNO3 to form the catalyst. The forming process is carried out according to the conventional method.

[0111] The formed catalyst is placed in an oven at 60-120°C for drying for 1-10 hours, and then calcined in a muffle furnace at 400-700°C for 1-10 hours;

[0112] At a pressure of 0.1-0.5 MPa(g), 100% water vapor (mass space velocity of water 1-6 h -1) Treating the catalyst at 400-600° C. for 2-20 hours and drying at 100-150° C. for 5-10 hours to obtain the solid acid catalyst used in the alkylbenzene production process of the present invention.

[0113] Normally, the alkylation reaction of straight-chain olefins with benzene will produce various straight-chain alkylbenzene isomers such as 2-LAB, 3-LAB, 4-LAB, and 5-LAB. Among them, 2-LAB has a long "tail" when sulfonated, which can improve solubility and washing performance and has the best biodegradability. It is the most needed product in industry. Therefore, the catalyst used in LAB production needs to have a high selectivity for 2-LAB.

[0114] Specifically, the 2-LAB refers to a linear alkylbenzene obtained by combining the carbon atom at position 2 of a linear olefin with benzene, and the 3-LAB refers to a linear alkylbenzene obtained by combining the carbon atom at position 3 of a linear olefin with benzene, wherein positions 2 and 3 of the carbon atom are the numbers of the carbon atoms in the linear olefin, the terminal carbon atom of the linear olefin is the carbon atom at position 1, and positions 2 and 3 refer to two numbers arranged in sequence from one end numbered 1 to the other end. It can be understood that the linearity of 2-LAB is greater than that of 3-LAB.

[0115] The solid acid catalyst selected by the present invention has a high 2-alkylbenzene selectivity (up to 50%), and the catalyst has a one-way service life of up to 3 months, avoiding repeated regeneration of the catalyst, reducing the difficulty of operation and saving energy consumption.

[0116] In addition, the existing solid acid catalysts usually have complex components and complicated preparation methods, while the solid acid catalyst used in the present invention has simple components, is easy to prepare, and has low production cost.

[0117] In the linear alkylbenzene production process of the present invention, the conversion rate of linear olefins is greater than 99.5%, and the conversion rate refers to the ratio of the amount of linear olefins participating in the reaction to the total amount of linear olefins entering the linear alkylbenzene reaction distillation tower 10. In addition, in the linear alkylbenzene produced by the present invention, the mass proportion of 2-LAB is greater than 50%, and the mass proportion of 3-LAB is greater than 35%.

[0118] It is understood by those skilled in the art that when impurities such as alkanes are mixed in the linear olefins used as the production raw materials, since the alkanes do not participate in the alkylation reaction, they will be mixed with the reaction products, resulting in the linear alkylbenzene separated from the linear alkylbenzene separation tower 30 also being mixed with alkanes. In view of this situation, it is necessary to add an alkane separation device to the linear alkylbenzene production equipment to remove the alkanes in the linear alkylbenzene.

[0119] Specifically, Figure 2As shown, the linear alkylbenzene production equipment may further include an alkane separation device connected to the linear alkylbenzene separation device.

[0120] Specifically, the alkane separation device includes an alkane separation tower 80, an alkane collection reflux system connected to the alkane separation tower 80, and a third reboiler 23;

[0121] The alkane separation tower 80 includes a third distillation section 81 and a third stripping section 82 which are sequentially arranged from top to bottom. The alkane collecting reflux system is connected to the third distillation section 81 , and the third reboiler 23 is connected to the third stripping section 82 .

[0122] Specifically, the alkane collection and reflux system includes a third condenser 91 connected to the third distillation section 81, a third reflux tank 92 connected to the third condenser 91, and a third reflux pump 93 connected to the third reflux tank 92 and the third distillation section 81, respectively. The third reflux pump 93 is used to pump out the alkanes collected in the third reflux tank 92, a part of which is produced as a by-product, and the other part enters the third distillation section 81 for cooling to achieve temperature control of the third distillation section 81.

[0123] Specifically, the third reboiler 23 is used to heat the linear alkylbenzene located at the bottom of the tower (the third distillation section 82), and the vaporized linear alkylbenzene after heating is returned to the alkane separation tower 80 to provide the required heat for heat transfer and mass transfer in the alkane separation tower 80; a portion of the linear alkylbenzene that is not vaporized in the third reboiler 23 can be directly extracted as a product.

[0124] Specifically, in the alkane separation tower 80, the third distillation section 81 and the third stripping section 82 are both provided with trays, the number of trays in the third distillation section 81 is 1-40, and the number of trays in the third stripping section 82 is 1-40.

[0125] Specifically, in the alkane separation tower 80, the temperature of the third rectification section 81 is 90-200°C, and the temperature of the third stripping section 82 is 150-250°C.

[0126] Specifically, the pressure in the alkane separation tower 80 is 0-300 KPa. Specifically, the pressure in the alkane separation tower 80 gradually increases from the top to the bottom.

[0127] Specifically, for the case where alkanes are mixed in the linear olefins, the linear olefins are usually provided in the form of Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products, such as Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products containing C8-C13 linear olefins, Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products of C10-C15 linear olefins, Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products of C13-C18 linear olefins, Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products of C15-C20 linear olefins, and Fischer-Tropsch synthetic oil or linear alkane dehydrogenation products of C19-C24 linear olefins.

[0128] Specifically, in the case where alkanes are mixed in the linear olefins, the carbon number difference between the longest-chain alkane and the shortest-chain alkane should be less than 5, otherwise the alkane separation device cannot completely separate the alkanes from the linear alkylbenzenes; when the linear olefins do not contain alkanes, the carbon number of the linear olefins is not limited.

[0129] The linear alkylbenzene production process of the present invention is described in detail below in the form of specific embodiments.

[0130] Example 1

[0131] The straight-chain olefin used in this Example 1 is a C8 straight-chain olefin.

[0132] The linear alkylbenzene reactive distillation tower 10 has an inner diameter of 50 mm and a height of 3000 mm, wherein the height of the first distillation section 11 is 150 mm, the height of the reaction section 12 is 1200 mm, and the height of the first stripping section 13 is 1650 mm.

[0133] During the entire alkylbenzene production process, the ratio of the total amount of benzene added as a production raw material into the linear alkylbenzene reaction distillation tower 10 to the total amount of linear olefins is 1.05:1.

[0134] The reaction conditions and results are shown in Table 1. The results show that the mass proportion of C8 linear alkylbenzene in the reaction product is more than 95%, and the mass proportion of 2-LAB in the linear alkylbenzene is greater than 50%, and the mass proportion of 3-LAB is greater than 35%.

[0135] Table 1 Example 1 Reaction conditions and reaction results

[0136] Experiment No. 1 2 3 <![CDATA[WHSV of linear olefin (h -1 )]]> 0.20 0.25 0.30 Pressure of reaction section 12 (MPa(g)) 0.1～0.15 0.1～0.15 0.1～0.15 Temperature of reaction section 12 (°C) 150-200 150-200 150-200 Temperature of the first stripping section 13 (°C) 250-300 250-300 250-300 Reaction product composition (wt%) C8 linear alkylbenzene 98.42 97.64 96.08 Heavy Alkyl Benzene 1.58 2.36 3.92 Linear alkylbenzene composition (wt%) 2-LAB 51.39 51.02 50.74 3-LAB 36.04 35.89 35.66

[0137] Example 2

[0138] The straight-chain olefin used in this Example 2 is a C12 straight-chain olefin.

[0139] The linear alkylbenzene reactive distillation tower 10 has an inner diameter of 60 mm and a height of 3000 mm, wherein the height of the first distillation section 11 is 240 mm, the height of the reaction section 12 is 1260 mm, and the height of the first stripping section 13 is 1500 mm.

[0140] During the entire alkylbenzene production process, the ratio of the total amount of benzene added as a production raw material into the linear alkylbenzene reaction distillation tower 10 to the total amount of linear olefins is 1.08:1.

[0141] The reaction conditions and results are shown in Table 2. The results show that the mass proportion of C12 linear alkylbenzene in the reaction product is more than 95%, and the mass proportion of 2-LAB in the linear alkylbenzene is greater than 50%, and the mass proportion of 3-LAB is greater than 35%.

[0142] Table 2 Example 2 reaction conditions and reaction results

[0143] Experiment No. 1 2 3 <![CDATA[WHSV of linear olefin (h -1 )]]> 0.20 0.25 0.30 Pressure of reaction section 12 (MPa(g)) 0.12～0.17 0.12～0.17 0.12～0.17 Temperature of reaction section 12 (°C) 160-190 160-190 160-190 Temperature of the first stripping section 13 (°C) 240-280 240-280 240-280 Reaction product composition (wt%) C12 linear alkylbenzene 98.33 97.78 96.67 Heavy Alkyl Benzene 1.67 2.22 3.33 Linear alkylbenzene composition (wt%) 2-LAB 51.48 51.32 50.63 3-LAB 36.29 35.75 35.42

[0144] Example 3

[0145] The linear olefin used in this Example 3 is a mixed olefin, and the mixed olefin includes C8 linear olefin, C10 linear olefin and C12 linear olefin.

[0146] The linear alkylbenzene reactive distillation tower 10 has an inner diameter of 40 mm and a height of 3000 mm, wherein the height of the first distillation section 11 is 300 mm, the height of the reaction section 12 is 1200 mm, and the height of the first stripping section 13 is 1500 mm.

[0147] During the entire alkylbenzene production process, the ratio of the total amount of benzene added as a production raw material to the linear alkylbenzene reaction distillation tower 10 to the total amount of linear olefins is 1.1: 1. The reaction conditions and results are shown in Table 2. The results show that the mass proportion of linear alkylbenzenes (the sum of C8 linear alkylbenzenes, C10 linear alkylbenzenes and C12 linear alkylbenzenes) in the reaction product reaches more than 95%, and the mass proportion of 2-LAB in the linear alkylbenzenes is greater than 50%, and the mass proportion of 3-LAB is greater than 35%.

[0148] Table 3 Example 3 reaction conditions and reaction results

[0149] Experiment No. 1 2 3 <![CDATA[WHSV of linear olefin (h -1 )]]> 0.20 0.25 0.30 Pressure of reaction section 12 (MPa(g)) 0.13～0.16 0.13～0.16 0.13～0.16 Temperature of reaction section 12 (°C) 170-200 170-200 170-200 Temperature of the first stripping section 13 (°C) 260-290 260-290 260-290 Reaction product composition (wt%) C8 linear alkylbenzene 22.72 22.34 22.33 C10 linear alkylbenzene 36.16 36.16 35.85 C12 linear alkylbenzene 39.44 38.94 38.84 Heavy Alkyl Benzene 1.67 2.54 2.97 Linear alkylbenzene composition (wt%) 2-LAB 51.68 51.24 50.63 3-LAB 36.26 35.77 35.21

[0150] Example 4

[0151] The straight-chain olefin used in this Example 4 is a C8-C12 straight-chain olefin, in which an alkane is doped.

[0152] The linear alkylbenzene reactive distillation tower 10 has an inner diameter of 50 mm and a height of 3000 mm, wherein the height of the first distillation section 11 is 200 mm, the height of the reaction section 12 is 1400 mm, and the height of the first stripping section 13 is 1400 mm.

[0153] During the entire alkylbenzene production process, the ratio of the total amount of benzene added as a production raw material into the linear alkylbenzene reaction distillation tower 10 to the total amount of linear olefins is 1.06:1.

[0154] The reaction conditions and results are shown in Table 4. The results show that the mass proportion of linear alkylbenzenes (the sum of C8-C12 linear alkylbenzenes) in the reaction product is more than 95%, and the mass proportion of 2-LAB in the linear alkylbenzenes is greater than 50%, and the mass proportion of 3-LAB is greater than 35%.

[0155] Table 4 Example 4 reaction conditions and reaction results

[0156] Experiment No. 1 2 3 Mass space velocity of linear olefins (h-1) 0.20 0.25 0.30 Pressure of reaction section 12 (MPa(g)) 0.14～0.18 0.14～0.18 0.14～0.18 Temperature of reaction section 12 (°C) 180-200 180-200 180-200 Temperature of the first stripping section 13 (°C) 270-300 270-300 270-300 Reaction product composition (wt%) C8 linear alkylbenzene 14.25 14.03 13.98 C9 linear alkylbenzene 12.67 12.54 12.3 C10 linear alkylbenzene 20.31 20.26 20.04 C11 linear alkylbenzene 35.46 35.4 35.21 C12 linear alkylbenzene 16.03 15.98 15.74 Heavy Alkyl Benzene 1.28 1.79 2.73 Linear alkylbenzene composition (wt%) 2-LAB 51.73 51.37 50.24 3-LAB 36.21 35.75 35.09

[0157] In summary, the linear alkylbenzene production process of the present invention has the following advantages:

[0158] (1) The present invention adopts reactive distillation to carry out alkylbenzene reaction. Alkylbenzene reaction is an exothermic reaction. The heat released by the reaction can be used as a distillation heat source to fully utilize the process energy, thereby reducing production energy consumption. In addition, the heat generated by the alkylation reaction is absorbed by the rising airflow, which can also prevent the temperature of the reaction section 12 from being too high, causing the catalyst to be sintered and then causing the activity to decrease.

[0159] Preferably, the linear alkylbenzene reactive distillation tower is provided with a plurality of olefin inlets, so that the raw linear olefin can be fed in multiple streams, thereby increasing the instantaneous benzene-olefin ratio of the reaction, thereby increasing the yield of the target product (i.e., linear alkylbenzene), reducing the total benzene-olefin ratio required for the reaction, and reducing production costs.

[0160] (2) The catalyst used in the linear alkylbenzene production process of the present invention is a solid acid catalyst, which is non-corrosive to the reaction equipment and easy to regenerate and recycle. Furthermore, the present invention also selects a solid acid catalyst with simple components, easy preparation, and low production cost. The solid acid catalyst has high olefin conversion rate, high 2-LAB selectivity, and good stability.

[0161] (3) In the linear alkylbenzene production process of the present invention, liquid benzene entering from the top of the linear alkylbenzene reaction distillation tower 10 (i.e., the first distillation section 11) enters the reaction section 12 and continuously flushes the catalyst located in the reaction section 12, thereby flushing away coking materials (such as charcoal, etc.) formed on the surface of the catalyst, thereby preventing the catalyst from being covered with coking materials and causing the activity to decrease, thereby extending the service life of the catalyst.

[0162] (4) In the linear alkylbenzene production process of the present invention, reaction and distillation occur simultaneously, and the reaction product continuously flows into the linear alkylbenzene separation tower 30 for separation, which is conducive to the alkylation reaction proceeding in the forward direction.

[0163] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present invention.

[0164] Those skilled in the art will appreciate that the modules in the device in the implementation scenario can be distributed in the device in the implementation scenario according to the implementation scenario description, or can be changed accordingly and located in one or more devices different from the implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple sub-modules.

[0165] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for producing linear alkylbenzene, characterized in that: include: Provide linear alkylbenzene production equipment and linear alkylbenzene production raw materials; The linear alkylbenzene production raw materials include linear olefins and benzene, and the linear olefins and benzene are both in liquid state; The linear alkylbenzene production equipment comprises a linear alkylbenzene reaction device and a linear alkylbenzene separation device connected to the linear alkylbenzene reaction system; The linear alkylbenzene reaction device comprises a linear alkylbenzene reaction distillation tower, a benzene reflux system and a first reboiler connected to the linear alkylbenzene reaction distillation tower; the linear alkylbenzene reaction distillation tower comprises a first distillation section, a reaction section and a first stripping section arranged in sequence from top to bottom; a solid acid catalyst is arranged in the reaction section; The reaction section and / or the first rectifying section are provided with an olefin inlet; the first rectifying section and the first stripping section are both provided with a benzene input port; the number of the olefin inlets is 3 or more; the projection intervals of the 3 or more olefin inlets on the radial cross section of the linear alkylbenzene reactive distillation tower are uniformly distributed; The reaction section is also provided with a fixing device for fixing the solid acid catalyst; The solid acid catalyst comprises the following components and their mass proportions: molecular sieve 1 / 2-9 / 10, binder 1 / 10-1 / 2; the molecular sieve comprises one or more of H-MCM-36, H-MCM-49, H-MCM-56, H-PSH-3, H-SSZ-25, H-ITQ-1, H-ITQ-2, H-ZSM-5, H-ZSM-12, H-ZSM-35, and H-β; The inlet of the benzene reflux system is connected to the first rectifying section, and the outlet of the benzene reflux system is connected to the first rectifying section and the first stripping section; the first reboiler is connected to the first stripping section; During the production process, linear olefins and benzene enter the linear alkylbenzene reaction distillation tower via the olefin inlet and the benzene inlet respectively; part of the reflux benzene collected by the benzene reflux system enters the linear alkylbenzene reaction distillation tower via the first distillation section, and the other part enters the linear alkylbenzene reaction distillation tower via the first stripping section; during the production process, it is also necessary to supplement fresh raw benzene to the linear alkylbenzene reaction distillation tower, and this part of fresh raw benzene enters the linear alkylbenzene reaction distillation tower via the first stripping section.

2. The process for producing linear alkylbenzene according to claim 1, wherein: The first rectifying section is provided with a benzene output port and a first benzene input port, the first stripping section is provided with a second benzene input port, the benzene reflux system comprises a first condenser connected to the benzene output port, a first reflux tank connected to the first condenser, and a first reflux pump respectively connected to the first reflux tank, the first benzene input port and the second benzene input port, the first reflux pump is used to pump out the liquid benzene collected in the first reflux tank, a part of which is transported to the first benzene input port via a pipeline, and the other part is transported to the second benzene input port via a pipeline.

3. The process for producing linear alkylbenzene according to claim 2, wherein: Fresh raw benzene added to the linear alkylbenzene reaction distillation tower during the production process enters the linear alkylbenzene reaction distillation tower through the second benzene input port; The linear alkylbenzene production equipment further includes a first heater connected to the second benzene input port to heat fresh raw benzene and reflux benzene input through the second benzene input port.

4. The process for producing linear alkylbenzene according to claim 1, wherein: The linear alkylbenzene separation device comprises a linear alkylbenzene separation tower and a linear alkylbenzene collection and reflux system and a second reboiler connected to the linear alkylbenzene separation tower; the linear alkylbenzene separation tower comprises a second rectifying section and a second stripping section arranged in sequence from top to bottom; the inlet and the outlet of the linear alkylbenzene collection and reflux system are both connected to the second rectifying section, and the second reboiler is connected to the second stripping section; The second distillation section is provided with a linear alkylbenzene outlet and a linear alkylbenzene inlet, and the linear alkylbenzene collecting reflux system comprises a second condenser connected to the linear alkylbenzene outlet, a second reflux tank connected to the second condenser, and a second reflux pump respectively connected to the second reflux tank and the linear alkylbenzene inlet.

5. The process for producing linear alkylbenzene according to claim 4, characterized in that: The linear alkylbenzene collection and reflux system further comprises a heat exchanger disposed between the linear alkylbenzene output port and the second condenser; The linear alkylbenzene production equipment further includes a second heater located between the heat exchanger and an olefin input port on the linear alkylbenzene reactive distillation tower.

6. The process for producing linear alkylbenzene according to claim 1, characterized in that: The linear alkylbenzene reaction distillation tower is cylindrical and has the same diameter in each region, and the ratio of the height to the diameter of the linear alkylbenzene reaction distillation tower is 5-100:1; In the linear alkylbenzene reactive distillation tower, the ratio of the heights of the first distillation section, the reaction section and the first stripping section is 0-10:20-50:40-80.

7. The process for producing linear alkylbenzene according to claim 1, characterized in that: During the production process, the molar ratio of the reflux benzene fed into the linear alkylbenzene reaction distillation tower via the benzene reflux system to the linear olefin fed per unit time is 1-5:1, and the molar ratio of the feed rate of the supplemented fresh raw benzene to the linear olefin fed per unit time is 1-1.1:1; The temperature range of the first rectifying section is 80-120°C, and the temperature range of the reaction section and the first stripping section are both 150-300°C; During the production process, the pressure in the linear alkylbenzene reaction distillation tower is 0-0.3 MPa(g).

8. The process for producing linear alkylbenzene according to claim 1, characterized in that: The linear olefin is mixed with alkanes; the linear alkylbenzene production equipment also includes an alkane separation device connected to the linear alkylbenzene separation device.

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