Industrial naphthalene production system and method

Abstract

The invention relates to the technical field of industrial naphthalene production, and discloses an industrial naphthalene production system. Comprising a pretreatment tower, a distillation tower, a raw material feeding pipe, an industrial naphthalene cooler, a carbolic oil condensation cooler, a carbolic oil reflux tank, a carbolic oil extraction pipe, a first reflux pump, a first tower bottom circulating pump, a tower bottom reboiler, an industrial naphthalene condenser, an industrial naphthalene reflux tank, a second reflux pump, an industrial naphthalene extraction pipe, a heating furnace, a second tower bottom circulating pump and a feeding preheater, and a washing oil extraction pipe and a washing oil cooler. The invention further provides a production method applying the production system. According to the method, qualified industrial naphthalene is directly produced without dephenolization, sodium sulfate wastewater which is difficult to treat is not generated, and the method is green and environment-friendly. In addition, an atmospheric and vacuum process is adopted, redundant heat of the distillation tower is used for preheating raw materials and heating the pretreatment tower, and the energy consumption of the device can be reduced while the product quality is improved. The embodiment of the invention further provides a production method using the production system.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial naphthalene production, and in particular to an industrial naphthalene production system and method. Background Art

[0002] Naphthalene is a polycyclic aromatic hydrocarbon formed by two benzene rings connected through sharing two carbon atoms, with the chemical formula C 10 H8. It has colorless and shiny flaky crystals, is easy to sublimate, and has a special smell; it is insoluble in water but easily soluble in organic solvents such as ethanol, ether, and benzene. Naphthalene is an important organic chemical raw material and is widely used in synthetic fibers, rubber, resins, fuels, and the production of explosives, pesticides, etc. The resources of naphthalene mainly come from coking naphthalene and petroleum naphthalene. In terms of resource volume, coking naphthalene has excellent conditions. At present, except for a few factories that produce refined naphthalene according to needs, most factories produce industrial naphthalene products.

[0003] Industrial naphthalene generally refers to naphthalene products with a crystallization point of not less than 77.5 °C, a naphthalene content of not less than 95%, and other indicators meeting the national quality standard GB / T 6699-2015. The industrial naphthalene produced in China is mainly used for the production of phthalic anhydride, and then various fibers, plastics, plasticizers, resins, and paints are produced using phthalic anhydride as a raw material.

[0004] With the trend of centralization and large-scale of tar processing, the industrial naphthalene processing technology also correspondingly adopts large-scale and continuous rectification process flows. Most of China adopts the double-furnace and double-column continuous rectification process for industrial naphthalene and the single-furnace and double-column pressurized continuous rectification process flow.

[0005] Taking the naphthalene-containing fraction extracted from tar distillation as the raw material for industrial naphthalene production, to complete the production process of industrial naphthalene, it is generally divided into three stages, namely pretreatment of the raw material, preliminary distillation, and rectification. The pretreatment of the raw material is to chemically remove phenols or pyridine compounds in the naphthalene-containing fraction with alkali liquor or acid liquor in the fraction de-phenolization section. The fraction after chemical treatment enters the preliminary distillation tower and the rectification tower for distillation, and industrial naphthalene products are taken out from the top of the rectification tower. The heat of the distillation tower is provided by a heating furnace. However, the sodium sulfate process wastewater generated during this process is very difficult to treat. The existing industrial naphthalene distillation adopts the single-furnace and double-column pressurized continuous rectification process flow. In this process, the preliminary distillation tower operates at atmospheric pressure, and the rectification tower operates under pressure. Since the rectification tower operates under pressure, the operating temperature also increases accordingly, resulting in increased energy consumption. Summary of the Invention

[0006] The purpose of the present invention is to provide an environmentally friendly and energy-saving industrial naphthalene production system and method.

[0007] To achieve the above object, the present invention provides an industrial naphthalene production system, including a pretreatment tower, a distillation tower, a raw material feed pipe, an industrial naphthalene cooler, a phenol oil condensation cooler, a phenol oil reflux tank, a phenol oil extraction pipe, a first reflux pump, a first bottom circulation pump, a bottom reboiler, an industrial naphthalene condenser, an industrial naphthalene reflux tank, a second reflux pump, an industrial naphthalene extraction pipe, and a heating furnace;

[0008] The pretreatment tower is a vacuum tower, and the distillation tower is an atmospheric tower;

[0009] The raw material feed pipe is communicated with the industrial naphthalene cooler, the industrial naphthalene cooler is communicated with the middle part of the pretreatment tower, the phenol oil condensation cooler is communicated with the top of the pretreatment tower, the phenol oil reflux tank is communicated with the phenol oil condensation cooler, the inlet end of the first reflux pump is communicated with the phenol oil reflux tank, and the outlet end of the first reflux pump is communicated with the top of the pretreatment tower and the phenol oil extraction pipe;

[0010] The inlet end of the first bottom circulation pump is communicated with the bottom of the pretreatment tower, the outlet end of the first bottom circulation pump is communicated with the bottom reboiler and the middle part of the distillation tower, and the bottom reboiler is communicated with the bottom of the pretreatment tower;

[0011] The bottom reboiler is communicated with the top of the distillation tower, the industrial naphthalene condenser is communicated with the bottom reboiler, the industrial naphthalene reflux tank is communicated with the industrial condenser, the inlet end of the second reflux pump is communicated with the industrial naphthalene reflux tank, the outlet end of the second reflux pump is communicated with the top of the distillation tower and the industrial naphthalene cooler, and the industrial naphthalene extraction pipe is communicated with the industrial naphthalene cooler;

[0012] Both ends of the heating furnace are communicated with the bottom of the distillation tower.

[0013] As a preferred solution, it further includes a second bottom circulation pump, a feed preheater, and a wash oil extraction pipe,

[0014] The inlet end of the second bottom circulation pump is communicated with the bottom of the distillation tower, the outlet end is communicated with the feed preheater and the heating furnace, and the heating furnace is communicated with the bottom of the distillation tower,

[0015] The feed preheater is located between the industrial naphthalene cooler and the distillation tower, so that the raw material feed pipe, the industrial naphthalene cooler, the feed preheater, and the middle part of the pretreatment tower are communicated in sequence,

[0016] The wash oil extraction pipe is communicated with the feed preheater.

[0017] As a preferred solution, it further includes a wash oil cooler, which is located between the wash oil extraction pipe and the feed preheater, and connects the feed preheater, the wash oil cooler and the wash oil extraction pipe in sequence.

[0018] As a preferred solution, it further includes an extraction pump, which is connected to the phenol oil reflux tank, and the extraction pump makes the pretreatment tower operate under negative pressure.

[0019] The present invention also provides a method for producing industrial naphthalene, which uses the above production system and includes the following steps:

[0020] The raw material three-component mixed oil enters the industrial naphthalene cooler from the raw material feed pipe, exchanges heat with industrial naphthalene and then enters the pretreatment tower;

[0021] The phenol oil steam extracted from the top of the pretreatment tower is condensed and cooled by the phenol oil condensation cooler and then enters the phenol oil reflux tank. Part of the phenol oil in the phenol oil reflux tank is sent to the top of the pretreatment tower by the first reflux pump to control the temperature at the top of the pretreatment tower, and the other part is sent out.

[0022] The naphthalene wash oil at the bottom of the pretreatment tower is sent to the bottom reboiler by the first bottom circulation pump. After the naphthalene wash oil exchanges heat with the industrial naphthalene extracted from the top of the distillation tower in the bottom reboiler, part of it is sent to the bottom of the pretreatment tower to supply heat to the whole tower, and the other part is sent to the distillation tower.

[0023] The industrial naphthalene steam extracted from the bottom of the distillation tower exchanges heat with the naphthalene wash oil from the bottom of the pretreatment tower in the bottom reboiler, then enters the industrial naphthalene condenser, is further condensed and cooled and then enters the industrial naphthalene reflux tank. Part of the industrial naphthalene in the industrial naphthalene reflux tank is sent to the top of the distillation tower by the second reflux pump to control the top temperature, and the other part is sent to the industrial naphthalene cooler and sent out after cooling.

[0024] As a preferred solution, it further includes:

[0025] The wash oil at the bottom of the distillation tower is sent to the heating furnace by the second bottom circulation pump, and the other part is sent to the feed preheater. The wash oil in the heating furnace is heated and then sent to the bottom of the distillation tower to supply heat to the whole tower, and the wash oil in the feed preheater is sent out after heat exchange.

[0026] As a preferred solution, the raw material three-component mixed oil is heated to 120 - 150 °C after heat exchange with the wash oil in the feed preheater and then enters the pretreatment tower.

[0027] As a preferred solution, the phenol oil sent from the phenol oil reflux tank to the top of the pretreatment tower controls the temperature at the top of the pretreatment tower to be 90 - 120 °C.

[0028] As a preferred solution, the temperature of the naphthalene washing oil drawn from the bottom of the pretreatment tower is 190-200 °C, and the temperature of the naphthalene washing oil sent to the bottom of the pretreatment tower after heat exchange in the bottom reboiler is 200-210 °C.

[0029] As a preferred solution, the industrial naphthalene sent from the industrial naphthalene reflux tank to the top of the distillation tower controls the temperature at the top of the distillation tower to be 210-225 °C.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] After the raw material three-component mixed oil of the present invention enters the pretreatment tower, a part of the phenol oil drawn from the top of the pretreatment tower is sent out, thereby reducing the phenol content and producing qualified industrial naphthalene products. Therefore, the present invention directly produces qualified industrial naphthalene without phenol removal, does not generate difficult-to-treat sodium sulfate wastewater, and is green and environmentally friendly. In addition, the pretreatment tower of the present invention operates under reduced pressure, and the distillation tower operates under normal pressure, which can solve the corrosion problem of the equipment caused by the three-component mixed oil of raw materials without phenol removal. In addition, the industrial naphthalene in the distillation tower exchanges heat with the three-component mixed oil of raw materials and exchanges heat with the naphthalene washing oil in the pretreatment tower to supply the heat of the whole pretreatment tower, so that the present invention only needs one heating furnace. Therefore, the present invention adopts the atmospheric and vacuum distillation process, and the excess heat of the distillation tower is used for raw material preheating and pretreatment tower heating, which can reduce the energy consumption of the device while ensuring the product quality. Brief Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the industrial naphthalene production system in the first embodiment of the present invention.

[0033] Figure 2 It is a schematic structural diagram of the industrial naphthalene production system in the second embodiment of the present invention.

[0034] In the figure, 1 - pretreatment tower; 2 - distillation tower; 3 - raw material feed pipe; 4 - industrial naphthalene cooler; 5 - phenol oil condensation cooler; 6 - phenol oil reflux tank; 7 - phenol oil extraction pipe; 8 - first reflux pump; 9 - first bottom circulation pump; 10 - bottom reboiler; 11 - industrial naphthalene condenser; 12 - industrial naphthalene reflux tank; 13 - second reflux pump; 14 - industrial naphthalene extraction pipe; 15 - heating furnace; 16 - extraction pump; 17 - product cooler; 18 - second bottom circulation pump; 19 - feed preheater; 20 - washing oil extraction pipe; 21 - washing oil cooler. Detailed Embodiments

[0035] The following combines the drawings and embodiments to further describe in detail the specific embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0039] Embodiment 1

[0040] Such as Figure 1As shown in the figure, an industrial naphthalene production system according to a preferred embodiment of the present invention includes a pretreatment tower 1, a distillation tower 2, a raw material feed pipe 3, an industrial naphthalene cooler 4, a phenol oil condensation cooler 5, a phenol oil reflux tank 6, a phenol oil extraction pipe 7, a first reflux pump 8, a first bottom circulation pump 9, a bottom reboiler 10, an industrial naphthalene condenser 11, an industrial naphthalene reflux tank 12, a second reflux pump 13, an industrial naphthalene extraction pipe 14, and a heating furnace 15; the pretreatment tower 1 is a vacuum tower, and the distillation tower 2 is an atmospheric tower; the raw material feed pipe 3 is communicated with the industrial naphthalene cooler 4, the industrial naphthalene cooler 4 is communicated with the middle part of the pretreatment tower 1, the phenol oil condensation cooler 5 is communicated with the top of the pretreatment tower 1, the phenol oil reflux tank 6 is communicated with the phenol oil condensation cooler 5, the inlet end of the first reflux pump 8 is communicated with the phenol oil reflux tank 6, and the outlet end of the first reflux pump 8 is communicated with the top of the pretreatment tower 1 and the phenol oil extraction pipe 7; the inlet end of the first bottom circulation pump 9 is communicated with the bottom of the pretreatment tower 1, and the outlet end of the first bottom circulation pump 9 is communicated with the bottom reboiler 10 and the middle part of the distillation tower 2, and the bottom reboiler 10 is communicated with the bottom of the pretreatment tower 1; the bottom reboiler 10 is communicated with the top of the distillation tower 2, the industrial naphthalene condenser 11 is communicated with the bottom reboiler 10, the industrial naphthalene reflux tank 12 is communicated with the industrial condenser, the inlet end of the second reflux pump 13 is communicated with the industrial naphthalene reflux tank 12, and the outlet end of the second reflux pump 13 is communicated with the top of the distillation tower 2 and the industrial naphthalene cooler 4, and the industrial naphthalene extraction pipe 14 is communicated with the industrial naphthalene cooler 4; both ends of the heating furnace 15 are communicated with the bottom of the distillation tower 2.

[0041] After the raw material three - mixed oil of this embodiment enters the pretreatment tower 1, a part of the phenol oil extracted from the top of the pretreatment tower 1 is sent out, thereby reducing the phenol content and producing qualified industrial naphthalene products. Therefore, in this embodiment, qualified industrial naphthalene is directly produced without phenol removal, and no difficult - to - treat sodium sulfate wastewater is generated, which is green and environmentally friendly. In addition, the pretreatment tower 1 of this embodiment operates under reduced pressure, and the distillation tower 2 operates under normal pressure, which can solve the corrosion problem of the equipment caused by the raw material three - mixed oil without phenol removal. In addition, the industrial naphthalene in the distillation tower 2 exchanges heat with the raw material three - mixed oil and exchanges heat with the naphthalene washing oil in the pretreatment tower 1 to supply heat to the whole pretreatment tower 1. Therefore, only one heating furnace 15 is required for the present invention. Therefore, the present invention adopts the atmospheric and vacuum process, and the excess heat of the distillation tower 2 is used for raw material preheating and heating of the pretreatment tower 1, which can reduce the energy consumption of the device while ensuring the product quality.

[0042] The production system of this embodiment further includes an extraction pump 16, and the extraction pump 16 is communicated with the phenol oil reflux tank 6, and the extraction pump 16 makes the pretreatment tower 1 operate under negative pressure. Optionally, the extraction pump 16 is a liquid - ring vacuum pump.

[0043] In addition, the production system further includes a product cooler 17, which is located between the industrial naphthalene cooler 4 and the industrial naphthalene extraction pipe 14, enabling the industrial naphthalene cooler 4, the product cooler 17, and the industrial naphthalene extraction pipe 14 to be connected in sequence. After the industrial naphthalene exchanges heat with the raw material three-component mixed oil, it is further cooled and then sent out.

[0044] Embodiment 2

[0045] The difference between this embodiment and Embodiment 1 is that, based on Embodiment 1, the production system of this embodiment adds a heat exchange part.

[0046] As Figure 2 shown, in this embodiment, the production system further includes a second bottom circulating pump 18, a feed preheater 19, and a wash oil extraction pipe 20. The inlet end of the second bottom circulating pump 18 is connected to the bottom of the distillation column 2, and the outlet end is connected to the feed preheater 19 and the heating furnace 15. The heating furnace 15 is connected to the bottom of the distillation column 2. The feed preheater 19 is located between the industrial naphthalene cooler 4 and the distillation column 2, enabling the raw material feed pipe 3, the industrial naphthalene cooler 4, the feed preheater 19, and the middle part of the pretreatment column 1 to be connected in sequence. The wash oil extraction pipe 20 is connected to the feed preheater 19. In this embodiment, a part of the wash oil at the bottom of the distillation column 2 exchanges heat with the raw material three-component mixed oil through the feed preheater 19 for heating the raw material three-component mixed oil, and another part is sent to the bottom of the distillation column 2 after being heated by the heating furnace 15 to supply heat to the whole column, further utilizing the heat of the intermediate product, increasing the temperature of the raw material three-component mixed oil entering the pretreatment column 1, and reducing energy consumption. And the wash oil sent into the feed preheater 19 is sent out as a product through the wash oil extraction pipe 20. Therefore, the production system of this embodiment can produce industrial naphthalene, phenol oil, and wash oil, and at the same time avoid accumulation in the pretreatment column 1 and the distillation column 2.

[0047] Furthermore, the industrial naphthalene production system further includes a wash oil cooler 21, which is located between the wash oil extraction pipe 20 and the feed preheater 19, enabling the feed preheater 19, the wash oil cooler 21, and the wash oil extraction pipe 20 to be connected in sequence. The feed preheater 19 is further cooled and then extracted through the wash oil cooler 21.

[0048] The other structures of this embodiment are the same as those of Embodiment 1 and will not be elaborated here.

[0049] Embodiment 3

[0050] In a preferred embodiment of the present invention, an industrial naphthalene production method uses the production system of Embodiment 1 or Embodiment 2 and includes the following steps:

[0051] The raw material three-component mixed oil enters the industrial naphthalene cooler 4 from the raw material feed pipe 3, exchanges heat with the industrial naphthalene, and then enters the pretreatment column 1;

[0052] The phenol oil vapor extracted from the top of the pretreatment tower 1 is condensed and cooled by the phenol oil condenser cooler 5 and then enters the phenol oil reflux tank 6. Part of the phenol oil in the phenol oil reflux tank 6 is sent to the top of the pretreatment tower 1 by the first reflux pump 8 to control the temperature at the top of the pretreatment tower 1, and the other part is sent out.

[0053] Part of the naphthalene washing oil at the bottom of the pretreatment tower 1 is sent to the bottom reboiler 10 by the first bottom circulation pump 9. After the naphthalene washing oil exchanges heat with the industrial naphthalene extracted from the top of the distillation tower 2 in the bottom reboiler 10, part of it is sent into the bottom of the pretreatment tower 1 to supply heat to the whole tower, and the other part is sent into the distillation tower 2.

[0054] The industrial naphthalene vapor extracted from the bottom of the distillation tower 2 exchanges heat with the naphthalene washing oil from the bottom of the pretreatment tower 1 in the bottom reboiler 10, then enters the industrial naphthalene condenser 11, and after further condensation and cooling, it enters the industrial naphthalene reflux tank 12. Part of the industrial naphthalene in the industrial naphthalene reflux tank 12 is sent to the top of the distillation tower 2 by the second reflux pump 13 to control the top temperature, and the other part is sent to the industrial naphthalene cooler 4 and sent out after cooling.

[0055] Part of the washing oil at the bottom of the distillation tower 2 is sent into the heating furnace 15 by the second bottom circulation pump 18, and the other part is sent to the feed preheater 19. The washing oil in the heating furnace 15 is heated and then sent into the bottom of the distillation tower 2 to supply heat to the whole tower, and the washing oil in the feed preheater 19 is sent out after heat exchange.

[0056] Specifically, the raw material three - mixed oil is heated to 120 - 150 °C after heat exchange with the washing oil in the feed preheater 19 and then enters the pretreatment tower 1. The phenol oil sent from the phenol oil reflux tank 6 to the top of the pretreatment tower 1 controls the temperature at the top of the pretreatment tower 1 to be 90 - 120 °C. The temperature of the naphthalene washing oil extracted from the bottom of the pretreatment tower 1 is 190 - 200 °C, and the temperature of the naphthalene washing oil sent into the bottom of the pretreatment tower 1 after heat exchange in the bottom reboiler 10 is 200 - 210 °C. The industrial naphthalene sent from the industrial naphthalene reflux tank 12 to the top of the distillation tower 2 controls the temperature at the top of the distillation tower 2 to be 210 - 225 °C.

[0057] In this embodiment, the temperature of the raw material three - mixed oil entering the raw material feed pipe 3 is about 85 °C. It enters the industrial naphthalene cooler 4 through the raw material feed pipe 3, and then is sent to the feed preheater 193. After heat exchange with the washing oil, the temperature rises to about 136 °C and enters the pretreatment tower 1. The phenol oil vapor extracted from the top of the pretreatment tower 1 is condensed and cooled to 25 - 40 °C by the phenol oil condenser cooler 5 and then enters the phenol oil reflux tank 6. Part of the phenol oil in the phenol oil reflux tank 6 is sent to the top of the pretreatment tower 1 to control the top temperature at 98 - 110 °C, and the remaining phenol oil is sent out as a product.

[0058] The temperature of the naphthalene-wash oil drawn from the bottom of the pretreatment tower 1 is 190 - 200°C. A part of it is sent to the bottom reboiler 10 through the first bottom circulation pump 9, and the other part is sent into the distillation tower 2. After the naphthalene-wash oil in the bottom reboiler 10 exchanges heat with the refined naphthalene drawn from the top of the distillation tower 2, its temperature rises to about 208°C and is sent to the bottom of the pretreatment tower 1 to supply heat to the whole tower.

[0059] The refined naphthalene vapor drawn from the top of the naphthalene distillation tower 2 exchanges heat with the naphthalene-wash oil fraction at the bottom of the pretreatment tower 1 in the bottom reboiler 10, and its temperature drops to about 215°C. Then it enters the refined naphthalene condenser 11, is further condensed and cooled to about 155°C, and enters the refined naphthalene reflux tank 12. A part of the refined naphthalene in the refined naphthalene reflux tank 12 is sent to the top of the distillation tower 2 to control the top temperature at 210 - 225°C. The other part of the refined naphthalene is cooled by the refined naphthalene cooler 4, and then cooled again to 90 - 100°C by the product cooler 17 using warm water. The refined naphthalene is sent out as a product.

[0060] A part of the wash oil at the bottom of the distillation tower 2 is sent to the bottom of the distillation tower 2 through the second bottom circulation pump 18 after being heated by the heating furnace 15 to supply heat to the whole tower. The other part passes through the feed preheater 19 and the wash oil cooler 21 successively, and is cooled by the raw material three-component mixture oil and circulating water and then sent out.

[0061] In summary, the embodiment of the present invention provides a refined naphthalene production system, which includes a pretreatment tower 1, a distillation tower 2, a raw material feed pipe 3, a refined naphthalene cooler 4, a phenol oil condensation cooler 5, a phenol oil reflux tank 6, a phenol oil extraction pipe 7, a first reflux pump 8, a first bottom circulation pump 9, a bottom reboiler 10, a refined naphthalene condenser 11, a refined naphthalene reflux tank 12, a second reflux pump 13, a refined naphthalene extraction pipe 14, a heating furnace 15, a second bottom circulation pump 18, a feed preheater 19, a wash oil extraction pipe 20 and a wash oil cooler 21. After the raw material three-component mixture oil enters the pretreatment tower 1, a part of the phenol oil drawn from the top of the pretreatment tower 1 is sent out, thereby reducing the phenol content and producing qualified refined naphthalene products. Therefore, the embodiment of the present invention directly produces qualified refined naphthalene without phenol removal, and does not generate difficult-to-treat sodium sulfate wastewater, which is green and environmentally friendly. In addition, the pretreatment tower 1 in the embodiment of the present invention operates under reduced pressure, and the distillation tower 2 operates under normal pressure, which can solve the corrosion problem of the equipment caused by the raw material three-component mixture oil without phenol removal. Moreover, the refined naphthalene in the distillation tower 2 exchanges heat with the raw material three-component mixture oil and exchanges heat with the naphthalene-wash oil in the pretreatment tower 1 to supply heat to the whole pretreatment tower 1, so that only one heating furnace 15 is needed in the embodiment of the present invention. Therefore, the embodiment of the present invention adopts the atmospheric and vacuum distillation process, and the excess heat of the distillation tower 2 is used for raw material preheating and heating of the pretreatment tower 1, which can reduce the energy consumption of the device while ensuring the product quality. The embodiment of the present invention also provides a production method using the above production system.

[0062] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. An industrial naphthalene production system, characterized in that, It includes a pretreatment tower (1), a distillation tower (2), a raw material feed pipe (3), an industrial naphthalene cooler (4), a phenol oil condensation cooler (5), a phenol oil reflux tank (6), a phenol oil extraction pipe (7), a first reflux pump (8), a first bottom circulation pump (9), a bottom reboiler (10), an industrial naphthalene condenser (11), an industrial naphthalene reflux tank (12), a second reflux pump (13), an industrial naphthalene extraction pipe (14), and a heating furnace (15); The pretreatment tower (1) is a vacuum tower, and the distillation tower (2) is an atmospheric tower; The raw material feed pipe (3) is communicated with the industrial naphthalene cooler (4), the industrial naphthalene cooler (4) is communicated with the middle part of the pretreatment tower (1), the phenol oil condensation cooler (5) is communicated with the top of the pretreatment tower (1), the phenol oil reflux tank (6) is communicated with the phenol oil condensation cooler (5), the inlet end of the first reflux pump (8) is communicated with the phenol oil reflux tank (6), and the outlet end of the first reflux pump (8) is communicated with the top of the pretreatment tower (1) and the phenol oil extraction pipe (7); The inlet end of the first bottom circulation pump (9) is communicated with the bottom of the pretreatment tower (1), the outlet end of the first bottom circulation pump (9) is communicated with the bottom reboiler (10) and the middle part of the distillation tower (2), and the bottom reboiler (10) is communicated with the bottom of the pretreatment tower (1); The bottom reboiler (10) is communicated with the top of the distillation tower (2), the industrial naphthalene condenser (11) is communicated with the bottom reboiler (10), the industrial naphthalene reflux tank (12) is communicated with the industrial condenser, the inlet end of the second reflux pump (13) is communicated with the industrial naphthalene reflux tank (12), the outlet end of the second reflux pump (13) is communicated with the top of the distillation tower (2) and the industrial naphthalene cooler (4), and the industrial naphthalene extraction pipe (14) is communicated with the industrial naphthalene cooler (4); Both ends of the heating furnace (15) are communicated with the bottom of the distillation tower (2).

2. The industrial naphthalene production system according to claim 1, wherein It further includes a second bottom circulation pump (18), a feed preheater (19), and a wash oil extraction pipe (20), The inlet end of the second bottom circulation pump (18) is communicated with the bottom of the distillation tower (2), and the outlet end is communicated with the feed preheater (19) and the heating furnace (15), and the heating furnace (15) is communicated with the bottom of the distillation tower (2), The feed preheater (19) is located between the industrial naphthalene cooler (4) and the distillation tower (2), so that the raw material feed pipe (3), the industrial naphthalene cooler (4), the feed preheater (19), and the middle part of the pretreatment tower (1) are communicated in sequence, The wash oil extraction pipe (20) is communicated with the feed preheater (19).

3. The industrial naphthalene production system according to claim 2, wherein, It further includes a wash oil cooler (21), and the wash oil cooler (21) is located between the wash oil extraction pipe (20) and the feed preheater (19), so that the feed preheater (19), the wash oil cooler (21), and the wash oil extraction pipe (20) are connected in sequence.

4. The industrial naphthalene production system according to claim 1 or 2, characterized in that, It further includes an extraction pump (16), which is communicated with the phenol oil reflux tank (6), and the extraction pump (16) makes the pretreatment tower (1) operate under negative pressure.

5. A method for producing industrial naphthalene, characterized in that, Adopting the production system according to any one of claims 1-4, it includes the following steps: The raw material three-component mixed oil enters the industrial naphthalene cooler (4) from the raw material feed pipe (3), exchanges heat with industrial naphthalene and then enters the pretreatment tower (1); The phenol oil steam extracted from the top of the pretreatment tower (1) is condensed and cooled by the phenol oil condensation cooler (5) and then enters the phenol oil reflux tank (6). Part of the phenol oil in the phenol oil reflux tank (6) is sent to the top of the pretreatment tower (1) by the first reflux pump (8) to control the temperature at the top of the pretreatment tower (1), and the other part is sent out; Part of the naphthalene washing oil at the bottom of the pretreatment tower (1) is sent to the bottom reboiler (10) by the first bottom circulation pump (9). After the naphthalene washing oil exchanges heat with the industrial naphthalene extracted from the top of the distillation tower (2) in the bottom reboiler (10), part of it is sent to the bottom of the pretreatment tower (1) to supply heat to the whole tower, and the other part is sent to the distillation tower (2); The industrial naphthalene steam extracted from the bottom of the distillation tower (2) exchanges heat with the naphthalene washing oil from the bottom of the pretreatment tower (1) in the bottom reboiler (10), then enters the industrial naphthalene condenser (11), is further condensed and cooled and then enters the industrial naphthalene reflux tank (12). Part of the industrial naphthalene in the industrial naphthalene reflux tank (12) is sent to the top of the distillation tower (2) by the second reflux pump (13) to control the top temperature, and the other part is sent to the industrial naphthalene cooler (4) and sent out after cooling.

6. The industrial naphthalene production method according to claim 5, characterized in that, It further includes: Part of the washing oil at the bottom of the distillation tower (2) is sent into the heating furnace (15) by the second bottom circulation pump (18), and the other part is sent to the feed preheater (19). The washing oil in the heating furnace (15) is heated and then sent to the bottom of the distillation tower (2) to supply heat to the whole tower, and the washing oil in the feed preheater (19) is sent out after heat exchange.

7. The industrial naphthalene production method according to claim 6, characterized in that, The raw material three-component mixed oil is heated to 120-150°C after heat exchange with the washing oil in the feed preheater (19) and then enters the pretreatment tower (1).

8. The method for producing industrial naphthalene according to claim 5, characterized in that, The phenol oil sent from the phenol oil reflux tank (6) to the top of the pretreatment tower (1) controls the temperature at the top of the pretreatment tower (1) to be 90-120°C.

9. The industrial naphthalene production method according to claim 5, characterized in that, The temperature of the naphthalene washing oil extracted from the bottom of the pretreatment tower (1) is 190-200°C, and the temperature of the naphthalene washing oil sent to the bottom of the pretreatment tower (1) after heat exchange in the bottom reboiler (10) is 200-210°C.

10. The industrial naphthalene production method according to claim 5, characterized in that, The industrial naphthalene sent from the industrial naphthalene reflux tank (12) to the top of the distillation tower (2) controls the temperature at the top of the distillation tower (2) to be 210-225°C.

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