CN111909120A - Energy-saving separation process of water-containing ternary azeotropic system - Google Patents
Energy-saving separation process of water-containing ternary azeotropic system Download PDFInfo
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- CN111909120A CN111909120A CN202010734748.XA CN202010734748A CN111909120A CN 111909120 A CN111909120 A CN 111909120A CN 202010734748 A CN202010734748 A CN 202010734748A CN 111909120 A CN111909120 A CN 111909120A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/04—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
- C07D307/06—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms
- C07D307/08—Preparation of tetrahydrofuran
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/005—Processes comprising at least two steps in series
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- C—CHEMISTRY; METALLURGY
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- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/04—Purification; Separation; Use of additives by distillation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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Abstract
The invention provides an energy-saving separation process of a water-containing ternary azeotropic system, which comprises the following steps: preheating raw materials, feeding the preheated raw materials into a first separation tower, and conveying materials extracted from the bottom of the tower to a second separation tower for further rectification; the steam extracted from the top of the second separation tower exchanges heat with the material at the bottom of the first separation tower and is extracted as product tetrahydrofuran, and the toluene finished product extracted from the bottom of the second separation tower exchanges heat with the raw material and is extracted as product toluene; and (3) refluxing the material extracted from the top of the first separation tower, conveying the material to a membrane separation component for dehydration, and extracting and collecting the dehydrated retentate (namely a tetrahydrofuran finished product) serving as a heat exchange medium to exchange heat with the material at the bottom of the second separation tower to obtain the product tetrahydrofuran. The energy-saving separation of the water-containing ternary azeotropic system is carried out by using the method, the steam potential of the retentate of the membrane separation component is fully utilized, the integration of energy is realized, the energy consumption is reduced, and the consumption of primary steam is reduced. The whole device is simple and convenient to operate and stable in operation.
Description
Technical Field
The invention belongs to the field of dehydration and refining processes of mixed organic solvents, and particularly relates to an energy-saving separation process of a water-containing ternary azeotropic system.
Background
The distillation separation method is mostly adopted for the mixed solvent in industry, and for the mixed solvent system containing water, because one or more solvents form a binary azeotropic system or a multi-azeotropic system with water, the purification and the refining of the mixed solvent become complicated. The conventional rectification method has high energy consumption and complex process, and a third component is required to be added for an azeotropic system, so that the recovered solvent contains impurities, and the purity and the use quality of the product are influenced.
The membrane separation technology taking the steam permeation dehydration membrane as the core takes the steam partial pressure difference of the removed components as the driving force, shows great advantages in the field of organic solvent dehydration, has simple process route and low energy consumption, does not introduce a third component, and has high product purity. For a water-containing ternary azeotropic system used in the fine chemical industry, which has a complex system and contains certain impurities, a high-efficiency, reliable and energy-saving process needs to be found, and the problems of high energy consumption and low product purity of conventional rectification are solved.
Disclosure of Invention
The invention aims to solve the problems of high rectification energy consumption and the like of a ternary azeotropic system, and provides an energy-saving separation process of a water-containing ternary azeotropic system, which comprises the following steps: (1) conveying the raw materials to heat exchange equipment at a mass flow rate of 1800-2200 kg/h for preheating, after preheating to 50-70 ℃, feeding the raw materials into a first separation tower with an operating pressure of 75-85 kPa for rectification, and conveying materials extracted from the bottom of the first separation tower to a second separation tower with an operating pressure of 0.1-0.2 MPa for further rectification; (2) transferring heat between a tetrahydrofuran finished product extracted from the top of the second separation tower and a material at the bottom of the first separation tower, extracting the tetrahydrofuran product after heat exchange, transferring a toluene finished product extracted from the bottom of the second separation tower to heat exchange equipment to exchange heat with the raw material, and then extracting the toluene product; (3) and (3) refluxing the material extracted from the top of the first separation tower, conveying the material to a membrane separation component for dehydration, taking the dehydrated retentate (namely a tetrahydrofuran finished product) as a heat exchange medium to exchange heat with the material at the bottom of the second separation tower, extracting and collecting the product tetrahydrofuran, and directly discharging the permeate (namely water vapor) out of the system through a permeate treatment component.
In another aspect, the present invention provides an apparatus for use in the above process, comprising a first separation column, a membrane separation module and a second separation column, wherein: the membrane separation component is provided with a material inlet, a retentate outlet and a permeate outlet; the second separation tower is provided with a material inlet, a tower top gas material outlet and a tower bottom material outlet; the top of the first separation tower is connected with a material inlet of the membrane separation assembly; the bottom of the first separation tower is connected with a material inlet of a second separation tower; the retentate outlet of the membrane separation module is connected with the second separation tower.
The device and the method of the invention are used for energy-saving separation of the water-containing ternary azeotropic system, the steam potential of the retentate of the membrane separation component is fully utilized, the integration of energy is realized, the energy consumption is reduced, and the consumption of primary steam is reduced. The whole device is simple and convenient to operate and stable in operation.
Drawings
FIG. 1 is a schematic flow diagram of an energy-saving separation device containing a ternary azeotropic system, wherein:
1. a first heat exchange device; 2. a first separation column; 3. a membrane separation module; 4. a second separation column; 5. a second heat exchange device; 6. a third heat exchange device; 7. a permeate processing assembly; 8. a fourth heat exchange device; 9. a fifth heat exchange device.
Detailed Description
The following detailed description of the invention refers to the accompanying drawings.
The invention provides an energy-saving separation process of a water-containing ternary azeotropic system, which comprises the steps of preheating raw materials, then feeding the preheated raw materials into a first separation tower for separation, feeding materials at the top of the first separation tower into a membrane separation component for dehydration, and directly discharging a solvent at the membrane permeation side after dehydration out of the system; conveying the tower bottom material of the first separation tower to a second separation tower for further separation, and taking the tower top steam of the second separation tower as a heat exchange medium to exchange heat with the tower bottom material of the first separation tower to obtain a tetrahydrofuran product; conveying the finished product toluene extracted from the second separation tower to heat exchange equipment to exchange heat with the raw material, and cooling to obtain a toluene product; and the solvent on the membrane retentate side is used as a heat exchange medium to exchange heat with the material at the bottom of the second separation tower, and the tetrahydrofuran product is obtained after heat exchange.
In order to better implement the method provided by the invention, the invention provides a device special for energy-saving separation of the water-containing ternary azeotropic system used in the method, and the method uses the device. The energy-saving separation device of the water-containing ternary azeotropic system comprises a membrane separation unit and a rectification unit, wherein: the membrane separation unit comprises a first heat exchange device 1 and a membrane separation assembly 2; the first heat exchange device 1 is provided with a raw material inlet, a raw material outlet, a heat exchange medium inlet and a heat exchange medium outlet; the membrane separation component 2 is provided with a raw material inlet, a retentate outlet and a permeate outlet; a retentate outlet of the membrane separation component 2 is connected with a material inlet of the rectification unit; a material outlet of the rectification unit is connected with a heat exchange medium inlet of the first heat exchange device 1; the retentate outlet of the membrane separation component 2 is also connected with the material outlet of the rectification unit.
And (4) feeding the tetrahydrofuran water azeotrope subjected to primary rectification into a membrane separation unit, and performing a membrane separation process. Water molecules penetrate through the molecular sieve membrane to form permeate, and the permeate is discharged out of the system by the permeate treatment component. The tetrahydrofuran with larger molecular size is intercepted by the molecular sieve membrane to obtain the tetrahydrofuran product. And in the system design, heat exchange is formed between the product and the material so as to recycle the product heat source to heat the material.
In a particular embodiment, a first separation column 2, a membrane separation module 3 and a second separation column 4 are included, wherein: the membrane separation component is provided with a material inlet, a retentate outlet and a permeate outlet; the second separation tower 4 is provided with a material inlet, a tower top gas material outlet and a tower bottom material outlet; the first separation tower 2 is connected with a first heat exchange device 1 and is provided with a second heat exchange device 5 at the top of the tower and a third heat exchange device 6 at the bottom of the tower; the second separation tower 4 is provided with a tower bottom fourth heat exchange device, and a tower top gas outlet is connected with a fourth heat exchange device 9; the top gas outlet of the second separation tower 4 is also connected with a third heat exchange device 6; the top of the first separation tower 2 is connected with a material inlet of a membrane separation component 3; the bottom of the first separation tower 2 is connected with a material inlet of a second separation tower 4; the permeate outlet of the membrane separation module 3 is connected with a permeate processing module 7; the retentate outlet of the membrane separation module 3 is connected to the second separation column 4 via a fourth heat exchange device 8.
In the energy-saving separation device containing the water ternary azeotropic system, the following components are adopted:
the first heat exchange device 1 provides a place for heat exchange between the raw material and the finished product toluene, the toluene from the tower bottom of the second separation tower 4 enters the first heat exchange device 1 as a heat exchange medium, heat is exchanged to the mixed raw material of the water-containing toluene tetrahydrofuran and the water-containing tetrahydrofuran from the tower top steam of the first separation tower 3, and the temperature and the pressure of the mixed raw material entering the membrane separation assembly 2 are improved. According to the process requirements, the first heat exchange device 1 can be selected from, but not limited to, a fixed tube-plate type tube-and-tube heat exchanger, a floating head type tube-and-tube heat exchanger, a U-shaped tube-and-tube heat exchanger, a spiral plate type heat exchanger, a spiral tube wound heat exchanger and a plate type heat exchanger.
The first separation tower 2 is used for realizing the rectification and removal of the tetrahydrofuran azeotropic component, the normal-pressure azeotrope of tetrahydrofuran and water is extracted from the tower top, and the mixed material of toluene and tetrahydrofuran is extracted from the tower bottom. The first separation column 2 may be selected from, but not limited to, a tray column, a packed column.
The membrane separation unit is used for realizing the high-efficiency separation of isopropanol and water. For this purpose, the membrane separation unit is preferably an inorganic molecular sieve membrane separation unit, consisting of n (n is a positive integer) molecular sieve membrane modules 3. The membrane assembly can be a single tube pass or a plurality of tube passes, and the area of the single membrane assembly can be controlled between 5 square meters and 300 square meters. The number n of membrane modules arranged in each set is determined according to the separation purpose; when n is greater than 1, the membrane modules can be connected in series or in parallel according to the material condition, the separation target and the like. On the other hand, from the component structure, the present invention can adopt, but is not limited to, specific forms such as a thermostatic membrane component or a baffle-type membrane component. In the embodiment of the present invention, the molecular sieve membrane module may be specifically exemplified by, but not limited to, a plate-type, tubular-type, hollow fiber-type or spiral plate-type molecular sieve membrane module, preferably a tubular-type molecular sieve membrane module. Suitable types of molecular sieves include LTA, SOD, FAU, MOR, FER, MFI, PHI, BEA, CHA, ERI, and mixed crystal molecular sieve membranes thereof, preferably type A molecular sieve membranes.
The second separation tower 4 is used for realizing the rectification separation of tetrahydrofuran and toluene, tetrahydrofuran steam is extracted from the tower top, and toluene materials are extracted from the tower bottom. The second separation column 4 may be selected from, but not limited to, a tray column, a packed column.
The second heat exchange means 5 receives the overhead vapour from the first separation column 3 and condenses it to produce reflux. The second heat exchange device 5 can be selected from, but is not limited to, a fixed tube-plate type tube-and-tube heat exchanger, a floating head type tube-and-tube heat exchanger, a U-shaped tube-and-tube heat exchanger, a spiral plate type heat exchanger, a spiral tube wound heat exchanger, and a plate type heat exchanger.
The third heat exchange device 6 provides a heat exchange place for the toluene-tetrahydrofuran mixture and the tetrahydrofuran vapor, wherein the tetrahydrofuran vapor from the top of the second separation tower 4 enters the third heat exchange device 6 as a heat exchange medium to exchange heat with the toluene-tetrahydrofuran mixture, and the toluene-tetrahydrofuran mixture is heated and then enters the second separation tower 4. According to the process requirement, the third heat exchange device 6 can be selected from, but not limited to, a fixed tube-plate type tube-and-tube heat exchanger, a floating head type tube-and-tube heat exchanger, a U-shaped tube-and-tube heat exchanger, a spiral plate type heat exchanger, a spiral tube wound heat exchanger and a plate type heat exchanger.
The permeate processing module 7 is used for receiving the permeate from the membrane separation module 3 and further processing the permeate to directly discharge the permeate. The permeate processing component can be selected from but not limited to a vacuum unit and a vacuum unit with steam condensation recovery.
The fourth heat exchange device 8 receives the tower bottom material from the second separation tower 4, and the tower bottom material is condensed to generate reflux. The fourth heat exchange device 8 can be selected from, but is not limited to, a fixed tube-plate type tube-and-tube heat exchanger, a floating head type tube-and-tube heat exchanger, a U-shaped tube-and-tube heat exchanger, a spiral plate type heat exchanger, a spiral tube wound heat exchanger, and a plate type heat exchanger.
Said fifth heat exchange means 9 receives the tetrahydrofuran vapors and condenses them further to obtain the product tetrahydrofuran. The fifth heat exchange device 9 can be selected from, but is not limited to, a fixed tube-plate type tube-and-tube heat exchanger, a floating head type tube-and-tube heat exchanger, a U-shaped tube-and-tube heat exchanger, a spiral plate type heat exchanger, a spiral tube wound heat exchanger, and a plate type heat exchanger.
In the structural description of the above-mentioned device, the components that can be determined by those skilled in the art through the prior art in this field are not described, and these components can be exemplified but not limited to: piping for connecting the various devices, raw storage tanks for storing and/or supplying aqueous toluene tetrahydrofuran, product storage tanks for receiving/processing toluene and tetrahydrofuran products, and the like. In addition, in combination with the above description, those skilled in the art can determine the most appropriate device selection and type according to the design requirements and requirements under the guidance of the prior art, and it is needless to describe this.
In combination with the energy-saving separation device of the ternary azeotropic system containing water in the above embodiment, the energy-saving separation process of the ternary azeotropic system containing water according to the present invention can be further described as the following steps:
(1) conveying raw materials containing 3-15 wt% of water, 5-20 wt% of toluene and 70-80 wt% of tetrahydrofuran to a first heat exchange device at a mass flow rate of 1800-2200 kg/h for preheating 1, preheating to 60 +/-2 ℃, then rectifying in a first separation tower 2 with an operating pressure of 75-85 kPa, and conveying materials extracted from the bottom of the first separation tower 2 to a second separation tower 4 with an operating pressure of 0.1-0.2 MPa for further rectification; the first separation tower 2 is operated under negative pressure, the temperature of the top of the tower is 52-62 ℃, the temperature of a tower kettle is 65-75 ℃, and the reflux ratio of the top of the tower is 0.5-3; the temperature of the top of the second separation tower 4 is 70-85 ℃, the temperature of the bottom of the second separation tower is 110-130 ℃, and the reflux ratio of the top of the second separation tower is 0.5-3;
(2) exchanging heat between a tetrahydrofuran finished product extracted from the top of the second separation tower 4 and a material at the bottom of the first separation tower 2 in third heat exchange equipment 6, extracting the tetrahydrofuran product after heat exchange through fifth heat exchange equipment 9, conveying a toluene finished product extracted from the bottom of the second separation tower 4 to first heat exchange equipment 1 to exchange heat with the raw material, and then extracting the toluene product;
(3) exchanging heat of the material extracted from the top of the first separation tower 2 through a second heat exchange device 5, refluxing part of the heat exchanged material to the first separation tower 2, conveying part of the heat exchanged material to a membrane separation component 3 for dehydration, extracting and collecting dehydrated retentate (namely tetrahydrofuran finished product) serving as a heat exchange medium and tower bottom material of a second separation tower 4 as product tetrahydrofuran after exchanging heat with a fourth heat exchange device 8, and directly discharging the permeate (namely water vapor) out of the system through a permeate treatment component 7; the pressure of the retentate side of the membrane separation assembly is 0.5-0.7 MPa, the temperature is 120-140 ℃, and the permeate side is operated in vacuum.
The optimization of the overall solution according to the invention should take into account the influence of the combination of technical features on the overall solution in addition to the application of the above-mentioned preferred technical features. The invention provides a specific embodiment of the energy-saving separation process of the water-containing ternary azeotropic system to specifically illustrate the implementation mode and effect of the invention. In this example, the energy-saving separation apparatus containing a ternary azeotropic system is used in the method as illustrated in fig. 1, and the selection of each device in the apparatus is as follows:
the first heat exchange device 1 is a fixed tube-plate type tubular heat exchanger.
The first separation tower 2 is a packed tower.
The membrane separation component 3 is a tubular molecular sieve membrane component; the molecular sieve membrane is an A-type molecular sieve membrane.
The second separation tower 4 is a packed tower.
The second heat exchange device 5 is a fixed tube-plate type tubular heat exchanger.
The third heat exchange device 6 is a fixed tube-plate type tubular heat exchanger.
The permeate treatment component 7 adopts a vacuum unit with steam condensation and recovery.
The fourth heat exchange device 8 is a fixed tube-plate type tubular heat exchanger.
And the fifth heat exchange device 9 adopts a fixed tube-plate type tubular heat exchanger.
The energy-saving separation process of the water-containing ternary azeotropic system implemented by combining the device comprises the following steps:
(1) conveying raw materials containing 3 wt% of water, 17 wt% of toluene and 80 wt% of tetrahydrofuran to a fixed tube plate type tubular heat exchanger 1 at a mass flow rate of 2000kg/h, preheating to 60 ℃, and then rectifying in a packed tower 2 with an operating pressure of 80kPa (absolute pressure), 20 theoretical plates, a tower top temperature of 57 ℃, a tower bottom temperature of 70 ℃ and a tower top reflux ratio of 2; mixed liquid of tetrahydrofuran and toluene is extracted from the bottom of the packed tower 2, the mass flow rate is 646kg/h, the temperature is 70 ℃, 47.3 percent of tetrahydrofuran, 52.65 percent of toluene and less than 0.05 percent of water are contained, the mixed liquid is conveyed to a packed tower 4, the operation pressure is 0.15MPa, the number of theoretical plates is 25, the operation temperature of the top of the tower is 78 ℃, the operation temperature of the bottom of the tower is 120 ℃, and the reflux ratio is 2, and the packed tower 4 is further rectified;
(2) the mass flow rate of a tetrahydrofuran finished product extracted from the top of a packed tower 4 is 303kg/h, the mass fraction is more than 99.9%, the tetrahydrofuran finished product exchanges heat with materials at the bottom of a packed tower 2 in a fixed tube-plate type tubular heat exchanger 6, the tetrahydrofuran product after heat exchange is cooled to 40 ℃ by the fixed tube-plate type tubular heat exchanger 9 and then extracted, the mass flow rate of a toluene finished product extracted from the bottom of the packed tower 4 is 343kg/h, the mass fraction of the toluene is 99%, the temperature is 120 ℃, the tetrahydrofuran finished product is conveyed to the fixed tube-plate type tubular heat exchanger 1 to exchange heat with raw materials, and then the toluene product is extracted;
(3) after heat exchange is carried out on the material extracted from the top of the packed tower 2 through a fixed tube plate type tubular heat exchanger 5, part of the material flows back to the packed tower 2, part of the material is conveyed to a tubular molecular sieve membrane component 3 for dehydration, an A-type molecular sieve membrane is installed in the tubular molecular sieve membrane component 3, and the membrane area is set to be 48m2The steam pressure of the raw material on the membrane side is 0.6MPa, the temperature is 130 ℃, the vacuum operation is adopted on the permeation side, and the vacuum pressure is 1 kPa; the water content of the dehydrated retentate tetrahydrofuran finished product is 0.4 wt%, the dehydrated retentate tetrahydrofuran finished product is used as a heat exchange medium to exchange heat with the tower bottom material of the packed tower 4 in a fixed tube-plate type tubular heat exchanger 8, and the dehydrated retentate tetrahydrofuran finished product is collected as the tetrahydrofuran product after heat exchange; the mass flow rate of the permeate water vapor is 55kg/h, and the permeate water vapor is condensed to 0 ℃ by a vacuum unit 7 with steam condensation recovery and directly discharged out of the system.
The method realizes the removal of water through a membrane separation device, and simplifies the purification process of the tetrahydrofuran toluene mixed solvent. The heat source is provided for the first separation tower kettle through the steam at the top of the second separation tower, and the input of the energy of the external heat source of the first separation tower kettle is reduced. The tetrahydrofuran steam high-temperature taste of the membrane separation device provides a heat source for the tower kettle of the second separation tower, and reduces the input of external heat source energy. Preheating the tetrahydrofuran as the raw material by using the high-temperature toluene material extracted from the tower kettle of the second separation tower, and recovering heat energy again. The energy is effectively integrated, and the energy consumption and the operation cost are reduced.
Claims (8)
1. An energy-saving separation process of a ternary azeotropic system containing water is characterized by comprising the following steps:
(1) conveying the raw materials to heat exchange equipment at a mass flow rate of 1800-2200 kg/h for preheating, after preheating to 50-70 ℃, feeding the raw materials into a first separation tower with an absolute pressure of 75-85 kPa for rectification, and conveying the materials extracted from the bottom of the first separation tower to a second separation tower with an operating pressure of 0.1-0.2 MPa for further rectification;
(2) transferring heat between a tetrahydrofuran finished product extracted from the top of the second separation tower and a material at the bottom of the first separation tower, extracting the tetrahydrofuran product after heat exchange, transferring a toluene finished product extracted from the bottom of the second separation tower to heat exchange equipment to exchange heat with the raw material, and then extracting the toluene product;
(3) and (3) refluxing the material extracted from the top of the first separation tower, conveying the material to a membrane separation component for dehydration, taking the dehydrated retentate as a heat exchange medium to exchange heat with the material at the bottom of the second separation tower, extracting and collecting the product tetrahydrofuran, and directly discharging the permeate out of the system through a permeate treatment component.
2. The method according to claim 1, wherein in the step (1), the raw material contains 3-15 wt% of water, 5-20 wt% of toluene and 70-80 wt% of tetrahydrofuran.
3. The method according to claim 1, wherein in the step (1), the first separation tower is operated under negative pressure, the tower top temperature is 52-62 ℃, the tower bottom temperature is 65-75 ℃, and the tower top reflux ratio is 0.5-3.
4. The method according to claim 1, wherein in the step (1), the overhead temperature of the second separation tower is 70-85 ℃, the kettle temperature of the second separation tower is 110-130 ℃, and the overhead reflux ratio is 0.5-3.
5. The method according to claim 1, wherein in the step (3), the pressure of the retentate side of the membrane separation module is 0.5-0.7 MPa, the temperature is 120-140 ℃, and the permeate side is operated under vacuum.
6. The process according to claim 1, characterized in that it uses an energy-saving separation device comprising a ternary azeotropic system containing water, comprising a first separation column (2), a membrane separation module (3) and a second separation column (4), in which:
the membrane separation component (3) is provided with a material inlet, a retentate outlet and a permeate outlet; the second separation tower (4) is provided with a material inlet, a tower top gas material outlet and a tower bottom material outlet;
the top of the first separation tower (2) is connected with a material inlet of a membrane separation assembly (3); the bottom of the first separation tower (2) is connected with a material inlet of a second separation tower (4);
the retentate outlet of the membrane separation module (3) is connected with the second separation tower (4).
7. The method of claim 6, wherein: comprising a first separation column (2), a membrane separation module (3) and a second separation column (4), wherein:
the membrane separation component (3) is provided with a material inlet, a retentate outlet and a permeate outlet; the second separation tower (4) is provided with a material inlet, a tower top gas material outlet and a tower bottom material outlet;
the first separation tower (2) is connected with the first heat exchange equipment (1) and is provided with second heat exchange equipment (5) at the top of the tower and third heat exchange equipment (6) at the bottom of the tower; the second separation tower (4) is provided with a tower bottom fourth heat exchange device (8), and a tower top gas outlet is connected with a fourth heat exchange device (9); the top gas outlet of the second separation tower (4) is also connected with a third heat exchange device (6);
the top of the first separation tower (2) is connected with a material inlet of a membrane separation assembly (3); the bottom of the first separation tower (2) is connected with a material inlet of a second separation tower (4); the permeate outlet of the membrane separation module (3) is connected with a permeate processing module (7); the retentate outlet of the membrane separation module (3) is connected with the second separation tower (4) through a fourth heat exchange device (8).
8. The method of claim 7, comprising the steps of:
(1) conveying raw materials containing 3-15 wt% of water, 5-20 wt% of toluene and 70-80 wt% of tetrahydrofuran to a first heat exchange device at a mass flow rate of 1800-2200 kg/h for preheating (1), after preheating to 60 +/-2 ℃, feeding the raw materials into a first separation tower (2) with an operating pressure of 75-85 kPa for rectification, and conveying materials extracted from the bottom of the first separation tower (2) to a second separation tower (4) with an operating pressure of 0.1-0.2 MPa for further rectification; the first separation tower (2) is operated under negative pressure, the temperature of the top of the tower is 52-62 ℃, the temperature of a tower kettle is 65-75 ℃, and the reflux ratio of the top of the tower is 0.5-3; the temperature of the top of the second separation tower 4 is 70-85 ℃, the temperature of the bottom of the second separation tower is 110-130 ℃, and the reflux ratio of the top of the second separation tower is 0.5-3;
(2) the tetrahydrofuran finished product extracted from the top of the second separation tower (4) exchanges heat with the material at the bottom of the first separation tower (2) in a third heat exchange device (6), the tetrahydrofuran finished product is extracted as product tetrahydrofuran through a fifth heat exchange device (9) after heat exchange, the toluene finished product extracted from the bottom of the second separation tower (8) is conveyed to the first heat exchange device (1) to exchange heat with the raw material, and then the toluene finished product is extracted as product toluene;
(3) exchanging heat of a material extracted from the top of the first separation tower (2) through a second heat exchange device (5), partially refluxing to the first separation tower (2), partially conveying to a membrane separation component (3) for dehydration, extracting and collecting a dehydrated retentate (namely a tetrahydrofuran finished product) serving as a heat exchange medium and a tower bottom material of the second separation tower (4) as a product tetrahydrofuran after exchanging heat with a fourth heat exchange device (8), and directly discharging a permeate (namely water vapor) out of the system through a permeate treatment component (7); the pressure of the retentate side of the membrane separation assembly is 0.5-0.7 MPa, the temperature is 120-140 ℃, and the permeate side is operated in vacuum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010734748.XA CN111909120B (en) | 2020-07-27 | 2020-07-27 | Energy-saving separation process of water-containing ternary azeotropic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN113045386A (en) * | 2021-03-11 | 2021-06-29 | 南京师范大学 | Process method for separating tert-butyl alcohol-tetrahydrofuran-water mixed solvent by rectification-membrane separation integrated process |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102675029A (en) * | 2012-02-25 | 2012-09-19 | 中国石油大学(华东) | Method for separating methylcyclohexane and toluene through differential pressure thermal coupling extractive rectification |
| CN104027996A (en) * | 2013-12-27 | 2014-09-10 | 江苏九天高科技股份有限公司 | A pervaporation rectification coupled system and a use thereof |
| CN106431835A (en) * | 2016-09-19 | 2017-02-22 | 青岛理工大学 | Novel process and equipment for separating ethanol-water by differential pressure thermal coupling distillation |
| CN110938047A (en) * | 2019-11-28 | 2020-03-31 | 江苏九天高科技股份有限公司 | Tetrahydrofuran-benzene-water mixture separation process and device |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102675029A (en) * | 2012-02-25 | 2012-09-19 | 中国石油大学(华东) | Method for separating methylcyclohexane and toluene through differential pressure thermal coupling extractive rectification |
| CN104027996A (en) * | 2013-12-27 | 2014-09-10 | 江苏九天高科技股份有限公司 | A pervaporation rectification coupled system and a use thereof |
| CN106431835A (en) * | 2016-09-19 | 2017-02-22 | 青岛理工大学 | Novel process and equipment for separating ethanol-water by differential pressure thermal coupling distillation |
| CN110938047A (en) * | 2019-11-28 | 2020-03-31 | 江苏九天高科技股份有限公司 | Tetrahydrofuran-benzene-water mixture separation process and device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113045386A (en) * | 2021-03-11 | 2021-06-29 | 南京师范大学 | Process method for separating tert-butyl alcohol-tetrahydrofuran-water mixed solvent by rectification-membrane separation integrated process |
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