Membrane separation adsorption coupling device for organic solvent dehydration

Abstract

The utility model discloses a membrane separation adsorption coupling device for organic solvent dehydration, and relates to the technical field of separation equipment. Comprising a raw material tank, a steam generator, an evaporation tank, a membrane separation unit, an adsorption unit, a finished product condenser, a finished product tank, a condenser, a permeable material storage tank and the like. When the organic solvent is subjected to dehydration treatment, primary membrane separation dehydration is firstly performed through steam permeation, and then trace moisture in the solvent is further adsorbed and removed through the adsorption unit connected with the membrane separation unit; the respective advantages of a membrane separation technology and an adsorption separation technology are fully exerted, and the two technologies are coupled to solve the problems that the membrane separation technology is difficult to separate when a low-water-content solvent is separated and the membrane area needs to be remarkably increased, and the adsorption separation technology is short in regeneration period and high in energy consumption when an organic solvent with high water content is treated; the high efficiency and the stability of the dehydration process are ensured, and the method is an efficient organic solvent dehydration scheme which can be continuously operated.

Description

TECHNICAL FIELD

[0001] The utility model relates to separating equipment technical field, concretely relates to a membrane separation adsorption coupling device for organic solvent dehydration. BACKGROUND

[0002] Organic solvent dehydration is a very important link in chemical production and use process, and many organic solvents are easy to form azeotrope with water, so that it is difficult to separate organic solvents from water by conventional rectification, and therefore special rectification methods (such as azeotropic rectification, extraction rectification) are usually used for separation. However, such separation methods need to introduce a third component, and the introduction of other components may affect the purity of the original solvent, and there are problems such as high energy consumption, complex operation and difficult process.

[0003] In contrast, membrane separation technology has obvious economic advantages. The membrane separation process is mainly driven by the pressure difference between the raw material side and the permeation side, but when using this technology to separate high-concentration organic solvents, the small amount of water in the solvent will reduce the driving force across the membrane, increase the separation difficulty, and significantly increase the required membrane area, thereby greatly increasing the investment cost.

[0004] Unlike membrane separation technology, adsorption separation technology has low energy consumption and can be well used for trace water adsorption and separation process, but this separation technology is not very suitable for adsorption and separation of solvents with high water content, because the regeneration process has high energy consumption, and the adsorbent is easily saturated when adsorbing and separating solvents with high water content, and frequent regeneration will seriously shorten the service life of the adsorption column.

[0005] Based on the characteristics of the two separation technologies, it is speculated that if the membrane separation technology and the adsorption separation technology can be coupled, the membrane separation technology can be used to separate and remove most of the water in the solvent, and then the solvent on the retentate side can be further separated by the adsorption separation technology to remove trace water, which can not only reduce the difficulty of membrane separation, but also increase the service life of the adsorption separation unit, reduce the energy consumption required for frequent regeneration, and achieve a synergistic effect. SUMMARY

[0006] The utility model discloses a novel membrane separation adsorption coupling device for organic solvent dehydration, which combines membrane separation technology and adsorption separation technology for the dehydration of organic solvents, can fully exert the advantages of the two separation technologies, and improves the separation efficiency and effect.

[0007] The utility model discloses the technical scheme adopted is: a membrane separation adsorption coupling device for organic solvent dehydration, comprising:

[0008] A raw material tank is used to store organic solvent mother liquor.

[0009] A steam generator for generating steam to feed an evaporation tank;

[0010] An evaporation tank connected to the raw material tank and the steam generator for evaporating the organic solvent mother liquor to separate the light and heavy components;

[0011] A membrane separation unit connected to the evaporation tank for membrane separation and dehydration of the steam generated by the evaporation tank;

[0012] An adsorption unit connected to the retentate side of the membrane separation unit for adsorption and dehydration of the organic solvent after membrane separation and dehydration;

[0013] A product condenser connected to the adsorption unit for condensing the organic solvent product after adsorption and dehydration;

[0014] A product tank connected to the product condenser for collecting the condensed organic solvent product;

[0015] A condenser connected to the permeate side of the membrane separation unit for condensing the permeate;

[0016] A permeate storage tank connected to the condenser for collecting the condensed permeate.

[0017] Further, the other end of the permeate storage tank is connected to a vacuum pump, which is used to provide negative pressure for the permeate side of the membrane separation unit and the inside of the condenser.

[0018] Further, the membrane separation unit is composed of several membrane assemblies connected in series, and the membrane assemblies are connected to the top of the evaporation tank; the membrane assembly includes a tank body and a membrane separation unit arranged inside the tank body, and the membrane separation unit is composed of a plurality of membrane tubes combined in parallel; the membrane used for membrane separation is a water-priority permeable membrane, and a tank heating jacket is arranged outside the tank body.

[0019] Further, the adsorption unit includes several adsorption columns arranged in parallel, and the column body of the adsorption column is filled with adsorbent, and a column heating jacket is arranged outside the column body to ensure that the temperature inside the adsorption column is higher than the boiling point of the solvent, thereby preventing the organic solvent vapor from condensing when contacting the adsorbent. A sieve plate is arranged in the column body to support the adsorbent.

[0020] Further, the adsorption column is connected to a nitrogen regeneration unit, which includes a nitrogen tank, a heater, and a valve control group; the heater is used to heat the nitrogen flowing out of the nitrogen tank, and the valve control group is used to control the path of the nitrogen flowing into the adsorption column to generate two blowing modes of the adsorption column, i.e., nitrogen forward blowing and reverse blowing, and the regeneration of the adsorption column is achieved by switching between forward blowing and reverse blowing.

[0021] The gas flow direction from top to bottom is consistent with the gravity effect, which helps water or other adsorbents in the adsorbent (molecular sieve) to flow downward with the gas flow, reduces the residence in the bed, but the gas flow may not effectively penetrate the entire molecular sieve bed, resulting in incomplete regeneration at the bottom.

[0022] Different adsorption columns are used alternately, part of the adsorption columns are used for adsorption operation, and the remaining used adsorption columns can be regenerated by the nitrogen regeneration unit, and the regeneration is completed, and the standby is designed, so that the continuous use of the entire membrane separation and adsorption coupling device is realized, and the use efficiency is improved.

[0023] Further, the raw material tank and the evaporation tank are connected through a centrifugal pump, which is used to transport the organic solvent mother liquor in the raw material tank to the evaporation tank, so as to ensure that the evaporation rate of the solvent in the evaporation tank and the rate of the solvent transportation keep dynamic balance.

[0024] Further, a buffer tank is arranged between the membrane separation unit and the adsorption unit, the buffer tank is connected with the retentate side of the membrane separation unit, receives the organic solvent after preliminary membrane separation and dehydration treatment, mainly buffers the pressure fluctuation of the whole process, and ensures that the system runs more stably; The buffer tank is externally provided with a heating jacket to prevent the organic solvent vapor from being condensed into liquid due to temperature reduction.

[0025] Further, the membrane separation and adsorption coupling device further comprises a refrigeration and heating circulator, which is connected with the membrane assembly and the adsorption column in sequence, and is used for providing heat for the membrane assembly and the adsorption column.

[0026] The beneficial effects of the utility model are:

[0027] 1. Compared with the traditional preparation of organic solvent dehydration process, the membrane separation and adsorption coupling device disclosed by the utility model combines membrane separation technology and adsorption separation technology for dehydration of organic solvent, can exert the respective advantages of membrane separation and adsorption separation technology; This technical combination solves the problems of difficult separation and the need to significantly increase the membrane area of membrane separation technology in separating low water content solvent, and the problems of short regeneration cycle and high energy consumption of adsorption separation technology in treating high water content organic solvent;

[0028] 2. In this application, the membrane separation technology is selected as steam permeation. Compared with pervaporation, the coupling process selected as steam permeation can effectively avoid damage to the membrane caused by impurities in the raw material passing through the membrane surface in liquid state, and can reduce the phenomenon of concentration polarization; 3. The gaseous liquid flowing out from the retentate side after membrane separation can directly enter the adsorption unit for dehydration, meeting the feed demand of the adsorption unit, without the need for additional vaporization equipment, which can significantly reduce energy loss;

[0029] 4. In this application, the membrane module and the adsorption column are both provided with heating jackets, which can ensure the constant temperature in the membrane separation process and the adsorption separation process, ensure that the temperature in the adsorption column is higher than the boiling point of the solvent, and prevent the organic solvent vapor from condensing when contacting the adsorbent during the adsorption process;

[0030] 5. In this new type, the adsorption unit is connected with the nitrogen regeneration unit, the nitrogen regeneration unit includes a valve control group for controlling the path of nitrogen flowing into the adsorption column, two blowing modes of positive blowing and reverse blowing of nitrogen in the adsorption column are generated, and the regeneration of the adsorption column is realized by switching of the positive blowing and the reverse blowing. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a front view of the membrane separation and adsorption coupling device for organic solvent dehydration;

[0032] Figure 2 It is a front view of the membrane separation and adsorption coupling device for organic solvent dehydration;

[0033] Figure 3 It is a front view of the membrane separation and adsorption coupling device for organic solvent dehydration;

[0034] Figure 4 It is a front view of the membrane separation and adsorption coupling device for organic solvent dehydration;

[0035] Figure 5 It is a flow chart of the membrane separation and adsorption coupling device for organic solvent dehydration;

[0036] Figure 6 It is a structural schematic diagram of the membrane module;

[0037] Figure 7 It is a structural schematic diagram of the adsorption column;

[0038] In the drawings: 1-steam generator, 2-raw material tank, 3-centrifugal pump, 4-evaporation tank, 5-thermometer, 6-pressure gauge, 7-first membrane module, 8-second membrane module, 9-buffer tank, 10-first adsorption column, 11-second adsorption column, 12-heater, 13-permeate storage tank, 14-product condenser, 15-product tank, 16-flow controller, 17-vacuum pump, 18-condenser, 19-valve control group, 20-refrigeration and heating circulator;

[0039] 71 - tank body, 72 - membrane separation unit, 73 - tank body heating jacket, 74 - heat source inlet, 75 - heat source outlet, 76 - tank body upper head, 77 - tank body lower head;

[0040] 101 - column body, 102 - adsorbent, 103 - upper head, 104 - lower head, 105 - column heating jacket, 106 - heat source stream inlet, 107 - heat source stream outlet, 108 - sieve plate. DETAILED DESCRIPTION

[0041] The following examples further illustrate the content of the present application, but should not be construed as limiting the present application. Modifications and replacements made to the method, steps or conditions of the present application, without departing from the essence of the present application, all belong to the protection scope of the present application.

[0042] In the description of the present application, it is understood that the terms "mounting", "connection", "connecting" should be interpreted broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or connection through intermediate medium, or internal connection of two elements. For those skilled in the art, the meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In addition, in the description process of the embodiments of the present application, the device position relationship of "up", "down", "front", "back", "left", "right" and the like in all the figures are based on the drawings.

[0043] To solve the problems of high energy consumption and high cost of organic solvent dehydration in the prior art, the present application provides a membrane separation and adsorption coupling device for organic solvent dehydration, and the specific structure is referred to Figures 1-5 The device comprises a steam generator 1, a raw material tank 2, an evaporation tank 4, a membrane separation unit, an adsorption unit, a finished product condenser 14, a product tank 15, a condenser 18 and a permeate storage tank 13.

[0044] The steam generator 1 is connected with the evaporation tank 4 and is used to generate steam for the evaporation tank 4.

[0045] The raw material tank 2 is used to store the organic solvent mother liquor which needs to be dehydrated, and is connected with the centrifugal pump 3 and the evaporation tank 4. Under the action of the centrifugal pump 3, the organic solvent mother liquor in the raw material tank 2 is transported to the evaporation tank 4, so as to ensure that the evaporation rate of the solvent in the evaporation tank 4 and the transportation rate of the solvent keep dynamic balance.

[0046] Evaporation tank 4, connecting raw material tank 2 and steam generator 1, using hot steam to evaporate the organic solvent mother liquor inside, so that the light and heavy components are separated. By adjusting the opening of the valve on the connecting pipeline between steam generator 1 and evaporation tank 4, the amount of steam can be changed, thereby adjusting the temperature of evaporation tank 4.

[0047] Membrane separation unit, composed of two membrane assemblies (first membrane assembly 7 and second membrane assembly 8) in series, connected to the top of evaporation tank 4, used for membrane separation and dehydration of the steam generated in evaporation tank 4. Thermometer 5 and pressure gauge 6 are provided on the connecting pipeline between evaporation tank 4 and membrane separation unit to monitor the temperature and pressure in evaporation tank 4 in real time.

[0048] The first and second membrane assemblies 7 / 8 are the same structure, taking the first membrane assembly 7 as an example, the first membrane assembly 7 includes a tank body 71 and a membrane separation unit 72 provided inside it, the membrane separation unit 72 is composed of a plurality of membrane tubes in parallel, the membrane used for membrane separation is a water-priority permeable membrane, which can be removed and replaced, a tank heating jacket 73 is provided outside the tank body 71 for heating the tank body 71, a heat source inlet 74 and a heat source outlet 75 are provided correspondingly on the tank heating jacket 73, the tank heating jacket 73 is used to ensure the constant temperature during membrane separation. The top and bottom of the tank body 71 are respectively provided with a tank upper head 76 and a tank lower head 77, and a permeation side outlet is provided on the upper head 21. This design makes the membrane separation unit 72 can effectively carry out the dehydration operation of organic solvent, at the same time has good temperature control ability and operation flexibility.

[0049] The permeation side outlet of the membrane assembly is connected with the condenser 18 for condensing the water permeated through the membrane (i.e. permeate); the condenser 18 is connected with the permeate storage tank 13, and the condensed permeate flows into the permeate storage tank 13 for storage. The other end of the permeate storage tank 13 is connected with a vacuum pump 17, which is used to provide negative pressure inside the permeation side of the membrane assembly and the condenser 18, thereby improving the separation efficiency of water.

[0050] A buffer tank 9 is provided between the membrane separation unit and the adsorption unit, which is connected with the retentate side of the first and second membrane assemblies 7 / 8, receives the organic solvent after preliminary dehydration treatment, and plays a role in stabilizing the pressure fluctuation of the system, ensuring the system runs more smoothly. The buffer tank 9 is provided with a heating jacket outside, which can prevent the organic solvent vapor from condensing into liquid due to temperature reduction when the system is running.

[0051] The adsorption unit is connected with the retentate side of the membrane separation unit through the buffer tank 9, and includes two adsorption columns (a first adsorption column 10 and a second adsorption column 11) connected in parallel, which are connected with the buffer tank 9 and loaded with adsorbents (such as molecular sieves), and the organic solvent gas after membrane separation dehydration is contacted with the adsorbents in the adsorption columns, so that the organic solvent after preliminary dehydration is dehydrated again to remove the residual trace water in the organic solvent.

[0052] The first and second adsorption columns 10 / 11 have the same structure, and the first adsorption column 10 is taken as an example. The column body 101 of the first adsorption column 10 is filled with adsorbents 102, which can be replaced as needed. The top and bottom of the column body 101 are sealed by an upper end cover 103 and a lower end cover 104 respectively to ensure the sealing of the device. A connecting port is arranged on the upper end cover 103 and the lower end cover 104 respectively to facilitate operation. A column heating jacket 105 is arranged outside the column body 101 to heat the column body 101, maintain the temperature in the adsorption column, and ensure that the temperature in the adsorption column is higher than the boiling point of the solvent to prevent the organic solvent vapor from condensing when contacting the adsorbents during the adsorption process. A heat source inlet 106 and a heat source outlet 107 are arranged on the column heating jacket 105 correspondingly. A sieve plate 108 is arranged in the column body 101 to support the adsorbents 102, so that the adsorbents 102 can be evenly distributed and stabilized in the column body 101. The above design of the adsorption column can ensure that the adsorption unit has good temperature control capability and can efficiently dehydrate the organic solvent.

[0053] The first and second adsorption columns 10 / 11 are connected with the nitrogen regeneration unit. The first and second adsorption columns 10 / 11 are used alternately. While one adsorption column is used for adsorption operation, the other adsorption column can be regenerated by the nitrogen regeneration unit, so that the entire membrane separation and adsorption coupling device can be used continuously.

[0054] The nitrogen regeneration unit includes a nitrogen tank (not shown in the figure), a heater 12, and a valve control group 19. The valve control group 19 is composed of valve a, valve b, valve c, and valve d. Valve a and valve b are connected in series, valve c and valve d are connected in series, and then valve a and b are connected in parallel with valve c and d. A flow controller 16 is further arranged on the connecting pipeline of the nitrogen tank and the heater 12.

[0055] When the regeneration operation is performed, open the nitrogen tank to start supplying nitrogen, open the heater 12 to heat the nitrogen to the required high temperature, open the valve a and the valve d, and close the valve b and the valve c. At this time, the high-temperature nitrogen will enter from the top of the adsorption column to be regenerated and flow downward, so as to regenerate the adsorbent in the adsorption column. After a period of regeneration from top to bottom, open the valve b and the valve c, and close the valve a and the valve d. At this time, the flow direction of the nitrogen will be switched to from bottom to top, so as to ensure that each part in the adsorption column is fully regenerated. After the regeneration operation is completed, the adsorption column will return to the standby state, ready for use again. Through the switching operation of the positive blowing and the reverse blowing, the flow direction advantage of the nitrogen can be fully utilized, and the adsorbent in the adsorption column can be thoroughly regenerated, so as to prolong the service life of the adsorption column and improve the regeneration efficiency.

[0056] The finished product condenser 14 is connected with the first and second adsorption columns 10 / 11, and is used for condensing the organic solvent product after the adsorption dehydration. The condensed product is collected in the finished product tank 15.

[0057] The coupling device further comprises a refrigeration and heating circulator 20, which is connected with the first membrane assembly 7, the second membrane assembly 8, the first adsorption column 10 and the second adsorption column 12 in sequence, and is used for providing a heat source for the membrane assemblies and the adsorption columns, so as to prevent the organic solvent gas from being condensed into liquid during the membrane separation and the adsorption separation, thereby affecting the dehydration effect.

[0058] The specific steps of using the coupling device to dehydrate the organic solvent are as follows:

[0059] Open the nitrogen tank to purge the whole device without heating the nitrogen, so as to discharge the air in the device. This step is mainly to isolate the external air and reduce the influence of the moisture in the air on the dehydration effect. Then open the vacuum pump 17 on the permeation side of the membrane assembly, so that the permeation side enters a negative pressure state. This helps to enhance the driving force in the membrane separation process and improve the dehydration efficiency. Open the refrigeration and heating circulator 20 to heat the membrane assemblies and the adsorption columns, so as to ensure that the vaporized organic solvent will not be condensed into liquid due to temperature reduction when entering the membrane assemblies and the adsorption columns, thereby maintaining the dehydration effect of the system. Start the steam generator 1 and open the centrifugal pump 3 to transport the organic solvent in the raw material tank 2 to the evaporation tank 4. The vaporized organic solvent in the evaporation tank 4 enters the membrane assembly for preliminary dehydration. The organic solvent preliminarily dehydrated on the retentate side of the membrane assembly is stored in the buffer tank 9. Thereafter, open the valve related to one of the adsorption columns, so that the membrane-separated and preliminarily dehydrated organic solvent enters the corresponding adsorption column for further adsorption separation. Open the finished product condenser 14, and the high-purity organic solvent vapor after the adsorption separation is condensed into liquid by the finished product condenser 14. The condensed liquid product enters the product tank 15, and finally the high-purity organic solvent is obtained.

[0060] The organic solvent can be selected from, but not limited to, alcohols, esters, ethers, aldehydes, furans, alkanes, and aromatic hydrocarbons, etc.

[0061] The membrane separation adsorption coupling device can effectively solve the problems of high energy consumption and high cost in the prior art, and provides a more efficient and economical method for organic solvent dehydration.

[0062] The basic principle, main features and advantages of the utility model are shown and described above. However, the above description is only a specific embodiment of the utility model, and the technical features of the utility model are not limited to this. Any other implementation mode obtained by any person skilled in the art without departing from the technical scheme of the utility model should be covered in the patent range of the utility model.

Claims

1. A membrane separation adsorption coupling device for organic solvent dehydration, characterized in that, The application relates to a membrane separation and adsorption coupling device. The device comprises: a raw material tank for storing an organic solvent mother liquor; a steam generator for generating steam for feeding an evaporation tank; the evaporation tank is connected with the raw material tank and the steam generator and is used for evaporating the organic solvent mother liquor; a membrane separation unit connected with the evaporation tank and used for carrying out membrane separation and dehydration on the steam generated by the evaporation tank; an adsorption unit connected with the retentate side of the membrane separation unit and used for carrying out adsorption and dehydration on the organic solvent after the membrane separation and dehydration; a product condenser connected with the adsorption unit and used for condensing the organic solvent product after the adsorption and dehydration; a product tank connected with the product condenser and used for collecting the condensed organic solvent product; a condenser connected with the permeate side of the membrane separation unit and used for condensing the permeate; 2. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, a permeate storage tank connected with the condenser and used for collecting the condensed permeate.

3. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, The other end of the permeate storage tank is connected with a vacuum pump, and the vacuum pump is used for providing negative pressure for the permeate side of the membrane separation unit and the inside of the condenser.

4. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, The membrane separation unit is composed of a plurality of membrane assemblies connected in series, and the membrane assemblies are connected with the top of the evaporation tank; the membrane assembly comprises a tank body and a membrane separation unit arranged in the inside of the tank body, the membrane separation unit is composed of a plurality of membrane tubes combined in parallel, the membrane used for the membrane separation is a water-priority permeation membrane, and a tank heating jacket is arranged outside the tank body.

5. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, The adsorption unit comprises a plurality of adsorption columns arranged in parallel, the column body of the adsorption column is filled with an adsorbent, a column heating jacket is arranged outside the column body, and a sieve plate is arranged in the column body and used for supporting the adsorbent.

6. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, Different adsorption columns are used alternately, the adsorption columns are connected with a nitrogen regeneration unit, the nitrogen regeneration unit comprises a nitrogen tank, a heater and a valve control group, the heater is used for heating the nitrogen flowing out of the nitrogen tank, the valve control group is used for controlling the path of the nitrogen flowing into the adsorption column, two blowing modes of positive blowing and reverse blowing of the adsorption column inside are generated, and the regeneration of the adsorption column is realized through switching of the positive blowing and the reverse blowing.

7. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to claim 1, characterized in that, The raw material tank and the evaporation tank are connected through a centrifugal pump, and the centrifugal pump is used for conveying the organic solvent mother liquor in the raw material tank to the evaporation tank.

8. The membrane separation adsorption coupled apparatus oriented to organic solvent dehydration according to any one of claims 3-4, characterized in that, A buffer tank is arranged between the membrane separation unit and the adsorption unit, the buffer tank is connected with the retentate side of the membrane separation unit and receives the organic solvent after the preliminary membrane separation and dehydration treatment, and a heating jacket is arranged outside the buffer tank. The membrane separation and adsorption coupling device further comprises a refrigeration and heating circulator connected with the membrane assembly and the adsorption column in sequence and used for providing heat for the membrane assembly and the adsorption column.

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