Device for producing mesitylene and durene through disproportionation of high-boiling-point aromatic hydrocarbon solvent

Abstract

The utility model discloses a device for producing mesitylene and durene through disproportionation of a high-boiling-point aromatic hydrocarbon solvent in the field of chemical production equipment, which comprises a tower body, a tower bottom discharge port is arranged at the bottom of the tower body, a gas phase outlet is arranged at the top of the tower body, and the gas phase outlet is connected with a condensing heat exchanger. The tower body comprises a lower disproportionation reaction section and an upper rectifying section, a catalyst layer is arranged in the disproportionation reaction section, and a feeding hole is formed in the lower part of the side surface of the disproportionation reaction section; the rectifying section is provided with five layers from top to bottom, each layer comprises a filler layer, a liquid collecting device is arranged below the filler layer, and the side surface of the liquid collecting device is connected with the outside through a side line extraction opening. According to the device, light components, mesitylene, intermediate components, durene and heavy components are collected through different side line extraction ports, separation can be carried out according to different boiling points of the light components, the mesitylene, the intermediate components, the durene and the heavy components, and the device is simple in equipment and low in energy consumption.

Description

Technical Field

[0001] The utility model relates to chemical production equipment, in particular to a device for simultaneously producing mesitylene and durene. Background Art

[0002] High boiling point aromatic solvent (SA for short) is a general term for a series of solvents composed of isomers of C9 and C10 heavy aromatics, mainly organic compounds composed of aromatics such as unisex trimethylol, 1-trimethylol, mesitylene, unisex tetramethylol, 1-tetramethylol, durene, n-propylbenzene, and isopropylbenzene. SA has the characteristics of high boiling point, low odor, low volatility, no water and olefins, no chlorine and heavy metals, good leveling, and excellent solubility. It has a wide range of applications in the industrial field. SA is mainly used in heavy machinery and equipment maintenance, metal cleaning and rust prevention, asphalt and paint, hydrogen peroxide production, pesticide emulsifiers, printing inks, coatings and resin solvents.

[0003] Mesitylene, colorless transparent liquid, melting point a Type-45℃; p Type -51℃, boiling point 164.7℃, relative density 0.864g / cm3, refractive index (nD) 1.4994, flash point 44℃. Autoignition point 550℃. Mesitylene is mainly used as a raw material for organic synthesis, used to prepare trimesic acid, and used as an antioxidant, epoxy resin curing agent, polyester resin stabilizer, and alkyd resin plasticizer.

[0004] Durene, white powder or monoclinic crystal, melting point 79.2℃, boiling point 196.8℃, relative density 0.8918g / cm3, flash point 73℃, soluble in ethanol, ether, benzene, insoluble in water. Durene is mainly used to prepare pyromellitic anhydride, and is also used to produce polyimide resins, dyes, plasticizers, surfactants, etc.

[0005] There are two main methods for preparing mesitylene: synthesis method and separation and purification method. The first type of synthesis method is divided into isomerization method and alkylation method: the isomerization method is to use trimethylol as raw material to carry out isomerization reaction to produce trimethylol; the alkylation method uses C9 aromatic mesitylene enriched liquid and propylene to obtain mesitylene through multiple alkylation or propylene and isobutylene combined alkylation. The second type of separation and purification method is to use C9 mixed aromatics, which are by-products of catalytic reforming, ethylene, paraxylene units, etc. in the petrochemical process, as raw materials, and directly distill and separate to extract the trimethylollene contained therein. Among a large number of by-product C9 mixed aromatics, 6-12% of trimethylollene is generally contained.

[0006] The process synthesis routes of tetramethylbenzene mainly include distillation-crystallization method and chemical synthesis method. One is the distillation-crystallization method, which uses the by-products in the processing of petroleum and coal, mainly the heavy components of methanol-to-gasoline or C10 heavy aromatics as raw materials for distillation-crystallization purification; the other is the chemical synthesis method, which mainly includes the alkylation reaction of trimethylbenzene and methanol, the isomerization reaction of trimethylbenzene, the isomerization reaction of tetramethylbenzene, etc.

[0007] Invention patent CN113045379A1 discloses a method for the alkylation-isomerization co-production of mesitylene and durene in the field of organic chemical production technology of C8 or C9 aromatics, wherein C8 or C9 aromatics and methanol are subjected to alkylation reaction to generate mesitylene and durene enriched liquid; trimethylol and durene are obtained through multiple fractionation, and the partial trimethylol, 3-trimethylol, partial tetramethylol and 3-tetramethylol separated in the reaction are returned to the isomerization reactor for isomerization reaction to generate mesitylene and durene enriched liquid, and cyclic separation is performed to obtain mesitylene and durene. This method has high product selectivity, few by-products, stable finished product quality, and is suitable for industrial production.

[0008] Invention patent CN103483136A1 discloses a method and device for hydroisomerization, distillation and concentration of mesitylene using trimethylol as raw material. The method comprises the following steps: extracting mesitylene from a mixed raw material or concentrated reaction product oil mainly using trimethylol, and then pressurizing the bottom oil with a pump, exchanging heat, and then entering a hydroisomerization reaction distillation tower through a feed port between the distillation section and the catalytic reaction section of the hydroisomerization reaction distillation tower; a part of the heavy components at the bottom of the tower is heated and returned to the bottom of the tower, and another part is used as a heavy separation device; a certain amount of circulating hydrogen is added to the bottom of the tower; the top gas is cooled and enters the gas-liquid separation reflux tank at the top of the tower, and the non-condensable gas at the top of the tank is further cooled and pressurized and heat-exchanged by a circulating machine and then returned to the bottom of the tower. The liquid phase in the tank is a concentrated solution of the reaction product oil, and a part of it is returned to the top of the tower as reflux; the other part is used to extract mesitylene, and the mass content of mesitylene in the concentrated solution of the reaction product oil is not less than 45%, and the content of components with a boiling point lower than or equal to trimethylol in the heavy components at the bottom of the tower is less than 4.0%.

[0009] Utility model patent CN215855846U discloses a device for isomerizing duren from unsymmetrical tetramethylbenzene and 3-tetramethylbenzene, wherein the pipeline at the bottom end of the reactor is connected to the pipeline of separator one through a heat exchanger, cooler one and the pipeline of separator one in sequence, the bottom end of separator one is connected to the isomerized liquid outlet pipeline, and the top end of separator one is connected to the pipeline of separator two through cooler two, the bottom end of separator two is connected to the isomerized liquid outlet pipeline, and the top end of separator two is connected to the pipeline of compressor through separator three, the compressor is connected to the pipeline of heating furnace through the heat exchanger, and the heating furnace is connected to the pipeline at the top end of the reactor; the pipeline between the compressor and the heating furnace is also connected to a hydrogen inlet pipeline and a mixed tetramethylbenzene feed pipeline, and the hydrogen inlet pipeline and the mixed tetramethylbenzene feed pipeline are both arranged before the heat exchanger, and unsymmetrical tetramethylbenzene and 3-tetramethylbenzene are used as raw materials for isomerization to generate duren.

[0010] In summary, the existing alkylation-isomerization, hydroisomerization-distillation, and isomerization devices for producing mesitylene and tetramethylene all have the problems of complex equipment, high energy consumption, many side reactions, and complex post-processing. Utility Model Content

[0011] The utility model aims to provide a device for producing mesitylene and durene by disproportionation of high boiling point aromatic solvents, so that mesitylene and durene can be produced simultaneously by using high boiling point aromatic solvents, and the device has simple equipment and low energy consumption.

[0012] The purpose of the utility model is achieved as follows: a device for producing mesitylene and tetramethylbenzene by disproportionation of high-boiling aromatic solvents comprises a tower body, a tower bottom discharge port is arranged at the bottom of the tower body, a gas phase outlet is arranged at the top of the tower body, the gas phase outlet is connected to a condensing heat exchanger, the tower body comprises a disproportionation reaction section in the lower section and a rectifying section in the upper section, a catalyst layer is arranged in the disproportionation reaction section, and a feed port is arranged at the lower part of the side of the disproportionation reaction section; the rectifying section is provided with five layers from top to bottom, each layer comprises a packing layer, a liquid collecting device is arranged below the packing layer, and the side of the liquid collecting device is connected to the outside through a side line production port.

[0013] Furthermore, the gas phase outlet is connected to the tube side inlet of the condensing heat exchanger, the tube side outlet of the condensing heat exchanger discharges non-condensable gas, and the condensate outlet of the condensing heat exchanger is connected to an automatic water separator, which includes a process water outlet at the bottom and an organic phase outlet at the side.

[0014] Furthermore, the shell side inlet of the condensing heat exchanger is connected to the high boiling point aromatic solvent, and the shell side outlet of the condensing heat exchanger is connected to the feed port after being mixed with water through a preheater.

[0015] Furthermore, the liquid collecting device of the first to fourth layers among the five layers of the distillation section includes a liquid baffle plate on one side and a liquid storage tank on the other side, the liquid storage tank and the liquid baffle plate are connected via a honeycomb perforated plate, and the corresponding side line production outlet is connected to the liquid storage tank; the liquid collecting device of the fifth layer includes a diversion collector, and the corresponding side line production outlet is connected to the bottom of the diversion collector.

[0016] Furthermore, the side line outlets corresponding to the five layers of the distillation section are connected to the light component collecting device, the mesitylene collecting device, the intermediate component collecting device, the mesitylene collecting device and the heavy component collecting device in sequence from top to bottom.

[0017] When the utility model is working, the high boiling point aromatic solvent first enters the condensing heat exchanger, is preliminarily heated, and then is mixed with water in the preheater, and then enters the disproportionation reaction section together, and enters the distillation section after the disproportionation reaction, and distills out mesitylene and tetramethylbenzene. The evaporated gas finally enters the condensing heat exchanger through the gas phase outlet, and after condensation, the non-condensable gas is discharged. At the same time, the condensed liquid passes through the automatic water separator to separate the process water and the organic phase, and the residual liquid is discharged from the discharge port at the bottom of the tower. Compared with the prior art, the utility model collects light components, mesitylene, intermediate components, tetramethylbenzene and heavy components through different side line extraction ports, and can be separated according to their different boiling points, and mesitylene and tetramethylbenzene are obtained at the same time. The device is simple and the energy consumption is low. High boiling point aromatic solvents can be used for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model.

[0019] Figure 2 This is a schematic diagram of the tower structure.

[0020] Figure 3 for Figure 2 A partial enlarged view of middle A.

[0021] In the figure, 1 is the discharge port at the bottom of the tower, 2 is the feed port, 3 is the preheater, 4 is the liquid collecting device, 401 is the liquid baffle plate, 402 is the orifice plate, 403 is the liquid storage tank, 404 is the side line extraction port, 5 is the tower body, 6 is the packing layer, 7 is the gas phase outlet, 8 is the condensation heat exchanger, 9 is the automatic water separator, 10 is the flow guide collector, 11 is the catalyst layer, L1 is the disproportionation reaction section, and L2 is the distillation section. DETAILED DESCRIPTION

[0022] like Figure 1-3As shown, a device for producing mesitylene and tetramethylbenzene by disproportionation of high-boiling point aromatic solvents comprises a tower body 5, a bottom discharge port 1 is provided at the bottom of the tower body 5, a gas phase outlet 7 is provided at the top of the tower body 5, and the gas phase outlet 7 is connected to a condensing heat exchanger 8. The tower body 5 comprises a disproportionation reaction section L1 in the lower section and a rectifying section L2 in the upper section. A catalyst layer 11 is provided in the disproportionation reaction section L1, and the catalyst layer 11 can be filled with one or more layers. A feed port 2 is provided at the lower part of the side of the disproportionation reaction section L1; the rectifying section L2 is provided with five layers from top to bottom, each layer comprises a packing layer 6, a liquid collecting device 4 is provided below the packing layer 6, and a side of the liquid collecting device 4 is connected to the outside through a side line production port 404.

[0023] The gas phase outlet 7 is connected to the tube side inlet of the condensing heat exchanger 8, and the tube side outlet of the condensing heat exchanger 8 discharges non-condensable gas. The condensate outlet of the condensing heat exchanger 8 is connected to the automatic water separator 9, and the automatic water separator 9 includes a process water outlet at the bottom and an organic phase outlet on the side.

[0024] The shell side inlet of the condensing heat exchanger 8 is connected to the high boiling point aromatic solvent, and the shell side outlet of the condensing heat exchanger 8 is connected to the feed inlet 2 after being mixed with water through the preheater 3 .

[0025] The liquid collecting device 4 of the first to fourth layers of the five layers of the distillation section L2 includes a liquid baffle plate 401 on one side and a liquid storage tank 403 on the other side, the liquid storage tank 403 and the liquid baffle plate 401 are connected via a honeycomb orifice plate 402, and the corresponding side line production port 404 is connected to the liquid storage tank 403; the liquid collecting device 4 of the fifth layer includes a diversion collector 10, and the corresponding side line production port 404 is connected to the bottom of the diversion collector 10. The diversion collector 10 can be a conical structure.

[0026] The side line outlets 404 corresponding to the five layers of the distillation section L2 are connected to the light component collecting device, the mesitylene collecting device, the intermediate component collecting device, the durene collecting device and the heavy component collecting device in sequence from top to bottom.

[0027] When the device is working, the disproportionation-distillation reaction process conditions are: high boiling point aromatic solvent and water are used as raw materials, the disproportionation catalyst is selected from mordenite, the disproportionation reaction pressure is 1.0MPa, the disproportionation reaction temperature is 280℃, the high boiling point aromatic solvent: water volume ratio = 9:1, and the volume space velocity is 1h -1 .

[0028] Process flow: The high-boiling-point aromatic solvent first enters the condensing heat exchanger 8, then enters the preheater 3 together with water, and then enters the disproportionation reaction section L1 together. The reaction product is rectified by the distillation section L2, and the distillation section L2 extracts the heavy components (197°C for unisomethylbenzene and 205°C for tetramethylbenzene) through the diversion collector 10; the distillation section L2 extracts 192°C for durene, intermediate components (176°C for trimethylbenzene and 168°C for unisomethylbenzene), 164.7°C for mesitylene, and light components (159.2°C for n-propylbenzene and 152°C for isopropylbenzene) through the side line of the liquid storage tank 403. The steam is condensed by the condensing heat exchanger 8, the non-condensable gas is discharged, and the condensed liquid is separated into process water and organic phase by the automatic water separator 9. The process water outlet pipe is bent upward from the bottom and then bent downward, and its bending height is flush with or slightly lower than the organic phase outlet. Usually, the density of process water is greater than the density of organic phase, and organic phase floats on the surface. The automatic water separator 9 can simultaneously flow out process water and organic phase by overflow. The liquid storage tank 403 is used to collect organic materials in different layers, and the liquid baffle plate 401 is used to block the liquid so that it accumulates on the orifice plate 402. The gas evaporated from the lower part can pass through the orifice plate 402, which can make the light component rise and the heavy component go down. The light component, heavy component, intermediate component, mesitylene and tetramethylbenzene are separated by different temperatures.

[0029] The present utility model is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present utility model, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present utility model.

Claims

1. A device for producing mesitylene and durene by disproportionation of high-boiling-point aromatic solvents, comprising a tower body, a bottom discharge port is provided at the bottom of the tower body, a gas phase outlet is provided at the top of the tower body, and the gas phase outlet is connected to a condensing heat exchanger, characterized in that: The tower body comprises a disproportionation reaction section in the lower section and a distillation section in the upper section. The disproportionation reaction section is provided with a catalyst layer, and a feed port is arranged at the lower side of the disproportionation reaction section. The distillation section is provided with five layers from top to bottom, each layer comprises a packing layer, a liquid collecting device is arranged below the packing layer, and a side of the liquid collecting device is connected to the outside through a side line production port.

2. The device for producing mesitylene and durene by disproportionation of high boiling point aromatic hydrocarbon solvents according to claim 1, characterized in that: The gas phase outlet is connected to the tube side inlet of the condensing heat exchanger, the tube side outlet of the condensing heat exchanger discharges non-condensable gas, and the condensate outlet of the condensing heat exchanger is connected to the automatic water separator, which includes a process water outlet at the bottom and an organic phase outlet on the side.

3. The device for producing mesitylene and durene by disproportionation of high boiling point aromatic hydrocarbon solvents according to claim 2, characterized in that: The shell side inlet of the condensing heat exchanger is connected to the high boiling point aromatic solvent, and the shell side outlet of the condensing heat exchanger is connected to the feed port after being mixed with water in a preheater.

4. The device for producing mesitylene and durene by disproportionation of high boiling point aromatic hydrocarbon solvents according to any one of claims 1 to 3, characterized in that: The liquid collecting devices of the first to fourth layers of the five layers of the distillation section include a liquid baffle plate on one side and a liquid storage tank on the other side. The liquid storage tank and the liquid baffle plate are connected via a honeycomb orifice plate, and the corresponding side line production outlet is connected to the liquid storage tank; the liquid collecting device of the fifth layer includes a diversion collector, and the corresponding side line production outlet is connected to the bottom of the diversion collector.

5. The device for producing mesitylene and durene by disproportionation of high boiling point aromatic solvents according to claim 4, characterized in that: The side line outlets corresponding to the five layers of the distillation section are connected to a light component collecting device, a mesitylene collecting device, an intermediate component collecting device, a tetramethylbenzene collecting device and a heavy component collecting device in sequence from top to bottom.

Images