CN219291376U

CN219291376U - System for synthesizing hydroxy acid

Info

Publication number: CN219291376U
Application number: CN202320121480.1U
Authority: CN
Inventors: 陈恩之; 苗迎彬; 赵风轩; 赵培朝; 谯映辉; 邓闯; 冯琪淞; 梁兴吕
Original assignee: CHONGQING HUAFON CHEMICAL CO LTD
Current assignee: CHONGQING HUAFON CHEMICAL CO LTD
Priority date: 2023-01-16
Filing date: 2023-01-16
Publication date: 2023-07-04
Anticipated expiration: 2033-01-16

Abstract

The utility model provides a system for synthesizing hydroxy acid, including the heat exchange column, reation kettle, the flash tank, the rectifying column, be provided with the filler section in the heat exchange column, its top sets up first top of the tower distributor, its lateral wall sets up cobalt salt catalyst import, the bottom of heat exchange column is through first pipeline feed to the reation kettle, set up the bottom of the tower distributor in the reation kettle, be used for linking to each other with the air source, the vapour phase export of reation kettle links to each other with the heat exchange column through the second pipeline, be located the below of filler section, the liquid phase export of reation kettle is through the third pipeline feed to the flash tank, the vapour phase export of flash tank links to each other with the lower part of rectifying column through the fourth pipeline, the oil phase export of flash tank links to each other with the lower part of rectifying column through the fifth pipeline, the aqueous phase export of flash tank links to each other with the tower reboiler material passageway of rectifying column through the sixth pipeline, be located the upper reaches of tower reboiler medium passageway. The utility model has simple structure and convenient operation, can effectively improve the utilization rate of heat energy and reduce the synthesis cost of hydroxy acid.

Description

System for synthesizing hydroxy acid

Technical Field

The utility model relates to the field of chemical industry, in particular to a system for synthesizing hydroxy acid.

Background

Dicarboxylic acids are important chemical precursor materials in the polymer chemistry industry and in organic synthesis. Adipic acid is a representative material in dicarboxylic acids, which is currently produced mainly via the process of cyclohexanol/cyclohexanone oxidation. Representative routes are: 1) The cyclohexane is oxidized to form cyclohexanol-cyclohexanone (ka oil), and the ka oil is oxidized to produce adipic acid; 2) Cyclohexene is hydrated to form cyclohexanol, and cyclohexanol is oxidized to produce adipic acid. In the first production route, the single-pass conversion rate of cyclohexane in the step of oxidizing cyclohexane to produce ka oil is low (the conversion rate of cyclohexane is usually lower than 6 percent), the operation condition of the reaction process is not easy to control, and accidents are easy to happen. The cyclohexene hydration route of the second production route has significant advantages in terms of safety of the process operation, but still has the following problems: 1) High purity requirement on cyclohexene and water raw materials. As the solubility of cyclohexene and cyclohexane and other upstream materials in water is close, the content of cyclohexane impurities in the cyclohexene raw material is reduced as much as possible, so that the negative influence of the cyclohexane impurity dissolution effect on the reaction rate is reduced; the oxygen content of the water in the raw material has an influence on the hydration reaction and must be reduced as much as possible; 2) The hydration reaction rate is slow. Cyclohexene has very little solubility in water due to polarity differences; causing a limitation of the reaction concentration to the reaction rate; 3) The single pass conversion is low. Cyclohexene hydration reactions are thermodynamic equilibrium limited reactions, and it has been reported that cyclohexene single pass conversion can only reach around 12% even with prolonged residence time of the cyclohexene starting material in the slurry reactor. 4) The reaction operation and subsequent separation and recycling costs are high. Since the reaction system is a three-phase complex system of oil phase (cyclohexene) -water phase-solid phase (molecular sieve). Strong stirring is needed to form an emulsifying system so as to improve the mass transfer of the reaction; the catalyst generates corresponding abrasion consumption in the stirring process, and the tiny catalyst generated by abrasion brings difficulty to the subsequent material separation; in addition, due to the single pass conversion of cyclohexene, a large amount of unreacted cyclohexene material needs to be recycled.

In addition to the representative routes described above, other routes for adipic acid synthesis have also been reported. us5166421 reports a process for preparing adipic acid from butadiene by two hydroformylation processes. The overall adipic acid yield of this route is not high and the cost of the noble metal catalyst used is high. gb1402480 reports a process for preparing dicarboxylic acids by adding a cyclic mono-olefin to a saturated aliphatic dibasic acid having 4 to 12 carbon atoms to form the corresponding dibasic ester, and oxidizing the resulting ester. The method has the advantages that the reaction raw materials used in the addition reaction step are solid-liquid two phases, so that the intermittent operation can be only performed, the reaction efficiency is low, and the final product and the raw materials are not easy to separate.

Therefore, based on the current state of the art, there is still a need to develop new adipic acid production processes in order to achieve the technical effects of high conversion, high selectivity, low unit consumption and low cost.

Disclosure of Invention

The utility model aims at overcoming the defects of the prior art, and provides a system for synthesizing hydroxy acid, which has the advantages of simple structure and convenient operation, can effectively improve the heat energy utilization rate and reduce the synthesis cost of hydroxy acid.

The technical scheme for realizing the aim of the utility model is as follows: the utility model provides a system for synthesizing hydroxy acid, includes heat exchange tower, reation kettle, flash tank, rectifying column, be provided with the filler section in the heat exchange tower, the top of heat exchange tower sets up first top of the tower distributor for link to each other with the cyclohexane source, the lateral wall of heat exchange tower sets up cobalt salt catalyst import, the bottom of heat exchange tower is through first pipeline to reation kettle feed, set up bottom of the tower distributor in the reation kettle for link to each other with the air source, the vapor phase export of reation kettle links to each other with the heat exchange tower through the second pipeline, is located the below of filler section, and the liquid phase export of reation kettle links to each other the flash tank feed through the third pipeline to the flash tank, the vapor phase export of flash tank links to each other with the middle part of rectifying column through the fourth pipeline, and the water phase export of flash tank links to each other with the tower bottom material passageway of rectifying column through the sixth pipeline, is located the reboiler medium passageway's of bottom.

And the third pipeline is connected with a seventh pipeline and is used for being connected with a desalted water source.

And the inlet of the tower bottom distributor is provided with a heat exchanger, and the medium inlet of the heat exchanger is connected with the tower top of the heat exchange tower through a pipeline.

The rectifying tower is a packed tower, and the downstream ends of the fourth pipeline and the fifth pipeline correspond to the packed sections of the rectifying tower.

The top of the rectifying tower is provided with a second tower top distributor which is used for being connected with a reflux liquid source.

The technical scheme has the following beneficial effects:

1. the system for synthesizing the hydroxy acid comprises a heat exchange tower, a reaction kettle, a flash tank and a rectifying tower, wherein the heat exchange tower utilizes reaction heat generated by the reaction kettle, is used for preheating materials entering the heat exchange tower, improves the utilization rate of the reaction heat in the reaction kettle, reduces the energy consumption of the reaction kettle, further achieves the purpose of reducing unit consumption and cost, the reaction kettle provides conditions and space for raw material reaction, the flash tank is used for separating an oxidation liquid sent by the reaction kettle, the oxidation liquid is separated into a vapor phase and a liquid phase (the liquid phase is layered into an oil phase and a water phase), and the rectifying tower is used for separating and purifying to obtain the hydroxy acid as a target product. The heat exchange tower is characterized in that a filler section is arranged in the heat exchange tower, a first tower top distributor is arranged at the top of the heat exchange tower and is used for being connected with a cyclohexane source, a cobalt salt catalyst inlet is formed in the side wall of the heat exchange tower, the bottom of the heat exchange tower is used for feeding a reaction kettle through a first pipeline, and cyclohexane raw materials are uniformly dispersed through the first tower top distributor and pass through the filler section and then are mixed with the added cobalt salt catalyst to be sent to the reaction kettle. The reaction kettle is internally provided with a tower bottom distributor which is used for being connected with an air source, a vapor phase outlet of the reaction kettle is connected with a heat exchange tower through a second pipeline, the vapor phase outlet of the reaction kettle is positioned below a filler section, air is taken as an oxidant, enters the reaction kettle in a bubbling mode through the tower bottom distributor and is fully mixed with cyclohexane, the contact area of the oxidant and the cyclohexane is effectively improved, the reaction efficiency and the reaction effect are improved, in addition, air is added into the reaction kettle in a bubbling mode, a gas ring is formed for a liquid phase of the cyclohexane, a cobalt salt catalyst is promoted to be uniformly distributed in the vapor phase, the efficient and balanced progress of the cyclohexane catalytic oxidation reaction is ensured, the generation of byproducts is avoided, the purity of a target product is improved, the vapor phase (vapor phase cyclohexane) carries heat to return to the heat exchange tower, and the filler section and the cyclohexane form full mass transfer and heat transfer, the raw cyclohexane is heated, and impurities are not introduced. The liquid phase outlet of the reaction kettle feeds the flash tank through a third pipeline, the vapor phase outlet of the flash tank is connected with the lower part of the rectifying tower through a fourth pipeline, the oil phase outlet of the flash tank is connected with the middle part of the rectifying tower through a fifth pipeline, the water phase outlet of the flash tank is connected with the tower bottom reboiler material channel of the distilling tower through a sixth pipeline and is positioned at the upstream of the tower bottom reboiler medium channel, namely, the vapor phase of flash evaporation enters the lower part of the rectifying tower, the non-flash oil phase enters the middle part of the rectifying tower, so that the oxidation liquid is fed at different positions of the rectifying tower, the gas-liquid phase exchange of the rectifying tower is facilitated, and the aim of heat recycling is fulfilled. The water phase enters a rectifying tower through a tower bottom reboiler, and is continuously heated and concentrated until being qualified.

2. The third pipeline is connected with a seventh pipeline and is used for being connected with a desalted water source, and the oxidation liquid generated in the reaction kettle is washed by adding desalted water, so that acid water generated in the chlorination reaction can be sufficiently washed and separated from the oil phase.

3. The inlet of the tower bottom distributor is provided with a heat exchanger, and the medium inlet of the heat exchanger is connected with the tower top of the heat exchange tower through a pipeline, so that the heat of the exothermic vapor phase can be further utilized, the temperature of air in the reaction kettle is increased, and the aim of reducing the energy consumption of the reaction kettle is achieved.

Further description is provided below with reference to the drawings and detailed description.

Drawings

FIG. 1 is a schematic diagram of the connection of the system of the present utility model.

In the drawing, 1 is a heat exchange tower, 2 is a reaction kettle, 3 is a flash tank, 4 is a rectifying tower, 5 is a first tower top distributor, 6 is a cobalt salt catalyst inlet, 7 is a tower bottom distributor, 8 is a heat exchanger, 9 is a second tower top distributor, 101 is a first pipeline, 102 is a second pipeline, 103 is a third pipeline, 104 is a fourth pipeline, 105 is a fifth pipeline, 106 is a sixth pipeline, and 107 is a seventh pipeline.

Detailed Description

In the utility model, all the raw materials are commercial products.

Example 1

Referring to fig. 1, a system for synthesizing hydroxy acid comprises a heat exchange tower 1, a reaction kettle 2, a flash tank 3 and a rectifying tower 4. Be provided with the filler section in the heat exchange column 1, the top of heat exchange column 1 sets up first top of the tower distributor 5 for link to each other with the cyclohexane source, the lateral wall of heat exchange column 1 sets up cobalt salt catalyst import 6, is located the below of filler section, the bottom of heat exchange column 1 is through first pipeline 101 to reation kettle 2 feed, and specifically, first pipeline connection is at reation kettle's lateral wall middle part. The reaction kettle 2 is internally provided with a tower bottom distributor 7 which is used for being connected with an air source, a vapor phase outlet of the reaction kettle 2 is connected with the heat exchange tower 1 through a second pipeline 102 and is positioned below a filling section, a liquid phase outlet of the reaction kettle 2 is used for feeding a flash tank 3 through a third pipeline 103, specifically, an inlet of the tower bottom distributor 7 is provided with a heat exchanger 8 which is positioned outside the reaction kettle, a medium inlet of the heat exchanger 8 is connected with the tower top of the heat exchange tower 1 through a pipeline, an inlet of the tower bottom distributor is connected with a material channel of the heat exchanger, and a seventh pipeline 107 is connected with the third pipeline 103 for being connected with a desalted water source so that acid water generated by a chlorination reaction can be sufficiently washed, separated from an oil phase and effectively removed from reaction heat of the chlorination reaction. The vapor phase outlet of the flash tank 3 is connected with the lower part of the rectifying tower 4 through a fourth pipeline 104, the oil phase outlet of the flash tank 3 is connected with the lower part of the rectifying tower 4 through a fifth pipeline 105, the water phase outlet of the flash tank 3 is connected with a tower bottom reboiler material channel of the distilling tower through a sixth pipeline 106 and is positioned at the upstream of a tower bottom reboiler medium channel, the rectifying tower 4 is a packed tower, the downstream ends of the fourth pipeline 104 and the fifth pipeline 105 correspond to the packed section of the rectifying tower, and a second tower top distributor 9 is arranged at the top of the rectifying tower and is used for being connected with a reflux liquid source.

Example 2

The hydroxy acid was synthesized using the system for synthesizing hydroxy acid of example 1, comprising the steps of:

1) Cyclohexane enters a heat exchange tower through a tower top distributor, and the flow is 10m ³ Mixing with cobalt salt catalyst, and feeding into a reaction kettle, wherein the content of the cobalt salt catalyst is 2ppm;

2) Air enters a reaction kettle through a tower bottom distributor, catalytic oxidation reaction is carried out at the temperature of 140-150 ℃ to obtain oxidation solution, and the flow rate of the air is 1000Nm ³ And/h, controlling the pressure of the reaction kettle to be 1MPa, wherein the generated vapor phase returns to the heat exchange tower through a second pipeline, and after the mass transfer and heat transfer are carried out on the filler section of the heat exchange tower and cyclohexane, the vapor phase is discharged out of the heat exchange tower, and the air entering the reaction kettle is continuously preheated;

3) The oxidation liquid generated in the reaction kettle is sent to a flash evaporation tank through a third pipeline, and the flow is 12m ³ And adding desalted water into the third pipeline through the seventh pipeline, wherein the flow rate is 1m ³ /h；

4) The vapor phase formed in the flash tank is sent to a rectifying tower through a fourth pipeline, the separated oil phase is sent to the rectifying tower through a fifth pipeline, the separated water phase is sent to the rectifying tower after being heated, specifically, the separated water phase is mixed with the circulating liquid of the tower bottom liquid of the rectifying tower, the temperature is raised to 85 ℃ through a reboiler at the tower bottom of the rectifying tower, the mixture enters the tower bottom of the rectifying tower, the tower top pressure of the rectifying tower is controlled to be 55kPa, the tower bottom temperature is 85 ℃, the tower top temperature is 78 ℃, the mass transfer and the heat transfer of the liquid phase and the vapor phase are carried out on the packing section of the rectifying tower, the hydroxy acid is obtained at the tower bottom of the rectifying tower, the content of the hydroxy acid is 24-26wt%, the conversion rate is 8.7%, and the yield is 79%.

Claims

1. A system for synthesizing hydroxy acids, characterized by: comprises a heat exchange tower (1), a reaction kettle (2), a flash tank (3) and a rectifying tower (4),

a filler section is arranged in the heat exchange tower (1), a first tower top distributor (5) is arranged at the top of the heat exchange tower (1) and is used for being connected with a cyclohexane source, a cobalt salt catalyst inlet (6) is arranged on the side wall of the heat exchange tower (1),

the bottom of the heat exchange tower (1) is used for feeding the reaction kettle (2) through a first pipeline (101),

the reaction kettle (2) is internally provided with a tower bottom distributor (7) which is used for being connected with an air source, a vapor phase outlet of the reaction kettle (2) is connected with the heat exchange tower (1) through a second pipeline (102) and is positioned below the filling section, a liquid phase outlet of the reaction kettle (2) is used for feeding the flash tank (3) through a third pipeline (103),

the vapor phase outlet of the flash tank (3) is connected with the lower part of the rectifying tower (4) through a fourth pipeline (104), the oil phase outlet of the flash tank (3) is connected with the middle part of the rectifying tower (4) through a fifth pipeline (105), and the water phase outlet of the flash tank (3) is connected with the tower bottom reboiler material channel of the rectifying tower through a sixth pipeline (106) and is positioned at the upstream of the tower bottom reboiler medium channel.

2. The system for synthesizing a hydroxy acid according to claim 1, wherein: the third pipeline (103) is connected with a seventh pipeline (107) for being connected with a desalted water source.

3. The system for synthesizing a hydroxy acid according to claim 1, wherein: the inlet of the tower bottom distributor (7) is provided with a heat exchanger (8), and the medium inlet of the heat exchanger (8) is connected with the tower top of the heat exchange tower (1) through a pipeline.

4. The system for synthesizing a hydroxy acid according to claim 1, wherein: the rectifying tower (4) is a packed tower, and the downstream ends of the fourth pipeline (104) and the fifth pipeline (105) correspond to the packed sections of the rectifying tower.

5. The system for synthesizing a hydroxy acid according to claim 1, wherein: the top of the rectifying tower (4) is provided with a second tower top distributor (9) which is used for being connected with a reflux liquid source.