Organic solvent dehydration system and method based on coupling of adsorption filtration and molecular sieve membrane dehydration

Abstract

The invention discloses an organic solvent dehydration system based on adsorption filtration and molecular sieve membrane dehydration coupling. The organic solvent dehydration system comprises a centrifugal pump, a filter A, a filter B, an adsorber A, an adsorber B, a heat exchanger, a membrane separation group vacuum assembly, a condenser, a buffer tank, a wastewater receiving tank, a product receiving tank and the like, the organic solution is endowed with mechanical energy and static pressure energy through a centrifugal pump and then enters a filter to remove large-particle impurities and a small part of other impurities; after large-particle impurities and a small part of other impurities are removed from the organic solution, the organic solution enters an adsorber to remove other specific impurities (metal ions, high-viscosity components, easily-polymerized components and the like); the organic solution is heated to a specific temperature through a heat exchanger after specific impurities are removed in an adsorber, and enters a membrane assembly for dehydration; dehydrating the organic solution to a specific water content in a membrane separation assembly; waste liquid generated by the membrane component is condensed and then enters the wastewater receiving tank; and the product dehydrated by the membrane module is cooled and then enters a product receiving tank.

Description

Technical Field

[0001] The present invention relates to a technical system for the purification and utilization of organic solvents, and particularly to a system and method for coupling filtration and molecular sieve membrane dehydration. Background Art

[0002] The dehydration and recovery of organic solvents refer to the dehydration and recovery treatment of water-containing organic solvents generated industrially. The current main dehydration methods are distillation, membrane separation, and adsorption. In particular, the molecular sieve membrane separation process is a separation method developed and applied in recent years, which has the advantages of low energy consumption, convenient operation, good separation effect, etc. The membrane separation method uses the difference in the adsorption and permeation rates of different components by the separation membrane to achieve the purpose of separation (CN214004476U). However, in the actual production process, the raw material composition is usually relatively complex. Large particle impurities, metal ions, high-viscosity components, and easily polymerizable components (such as ethers and aldehydes) contained in the raw materials will greatly reduce the separation efficiency and service life of the molecular sieve membrane.

[0003] Filtration adsorption is a well-developed purification method in industry, which can effectively remove large particle impurities in fluids. It can also effectively reduce metal ions, high-viscosity components, easily polymerizable components, etc. in fluids by selecting the functional layer of the filtration adsorption device. (CN 117205683 A, CN 113274780B) Summary of the Invention

[0004] The present invention is made in view of the above situation. The first object of the present invention is to provide an organic solvent dehydration system based on the coupling of adsorption filtration and molecular sieve membrane dehydration; the second object of the present invention is to provide an organic solvent dehydration method for the system.

[0005] The organic solvent dehydration system based on the coupling of adsorption filtration and molecular sieve membrane dehydration described in the present invention includes a centrifugal pump, Filter A, Filter B, Adsorber A, Adsorber B, heat exchanger, membrane separation unit, vacuum assembly, condenser, buffer tank, waste water receiving tank, product receiving tank, etc.; the organic solvent to be treated obtains static pressure energy, kinetic energy, etc. through the centrifugal pump and enters the filter to remove large particle impurities; then it enters the adsorber to remove specific impurities (metal ions, high-viscosity components, easily polymerizable components, etc.), and then enters the raw material side of the membrane module; the vacuum group is connected to the permeate side of the membrane module; the product enters the product receiving tank after being cooled by the heat exchanger. The waste liquid enters the waste water receiving tank after being condensed;

[0006] Preferably, the organic solution is an aqueous solution of methanol, ethanol, propanol, isopropanol (IPA), tetrahydrofuran, acetone, N-methylpyrrolidone (NMP), dimethyl carbonate, ethyl methyl carbonate, ether, dimethyl sulfoxide, etc. with good water solubility.

[0007] Preferably, an interlock control system is provided for the flow rate, pressure, and temperature control between the devices;

[0008] Preferably, the membrane module includes components such as a supporting heat exchanger, a membrane separator, a vacuum unit, a storage tank, etc.;

[0009] Preferably, the Filter A, Filter B, Adsorber A, and Adsorber B can be placed after the heat exchanger and before the membrane module;

[0010] Preferably, only one of the filtration component and the adsorption component can be introduced into the system, or both components can be introduced;

[0011] Preferably, the functional layers of the Filter A and Filter B components are: paper filter elements, chemical fiber filter elements, metal mesh filter elements, sintered metal powder filter elements, PP filter elements, wire gap filter elements, activated carbon filter elements, etc.;

[0012] Preferably, the functional layers of the Adsorber A and Adsorber B components are: zeolite molecular sieves, activated carbon, alumina, metal-organic frameworks (MOF), polyacrylamide, etc.;

[0013] The present invention provides a dehydration and purification method for the dehydration system, comprising the following steps:

[0014] (1) The organic solution is given mechanical energy and static pressure energy by a centrifugal pump and then enters the filter to remove large particulate impurities and a small part of other impurities;

[0015] (2) After the organic solution removes large particulate impurities and a small part of other impurities, it enters the adsorber to remove other specific impurities (metal ions, high-viscosity components, polymerizable components, etc.).

[0016] (3) After the organic solution removes specific impurities in the adsorber, it is heated to a specific temperature by a heat exchanger and enters the membrane module for dehydration;

[0017] (4) The organic solution is dehydrated in the membrane separation module to a specific water content.

[0018] (5) The waste liquid generated by the membrane module enters the waste water receiving tank after condensation.

[0019] (6) The product after dehydration treatment by the membrane module is cooled and then enters the product receiving tank.

[0020] Beneficial effects

[0021] Compared with the prior art, the present invention has obvious outstanding substantial features and remarkable advantages:

[0022] By coupling the processes of adsorption filtration and molecular sieve membrane dehydration, the present invention can effectively intercept the impurities that affect the efficiency of the molecular sieve membrane before the membrane separation module, avoid the influence on the membrane separation efficiency, and reduce the investment and use and maintenance costs of the membrane module. Description of the drawings

[0023] Figure 1 This is a schematic structural diagram of the organic solvent dehydration system based on the coupling of adsorption filtration and molecular sieve membrane dehydration of the present invention. Detailed implementation manners

[0024] This part will describe in detail the specific embodiments of the present invention, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be construed as a limitation on the protection scope of the present invention.

[0025] Example 1

[0026] The system purifies the ethanol - water organic solution as follows:

[0027] An ethanol - aqueous solution containing 5 wt% water and 1000 ppm sodium ions is used as the raw material.

[0028] (1) An ethanol - aqueous solution containing 5 wt% water and ~500 ppm sodium ions is given mechanical energy and static pressure energy by a centrifugal pump and then enters a filter to remove large - particle impurities and a small part of other impurities.

[0029] (2) After the ethanol - aqueous solution containing 5 wt% water and ~500 ppm sodium ions removes large - particle impurities and a small part of other impurities, it enters an adsorber (the functional layer of the adsorber is a cation - exchange resin) to reduce the sodium ion concentration to below 1000 ppb.

[0030] (3) The ethanol - aqueous solution containing 5 wt% water and ~500 ppm sodium ions is heated to a specific temperature through a heat exchanger after the sodium ion concentration is reduced in the adsorber and then enters the membrane module for dehydration.

[0031] (4) The ethanol - aqueous solution containing 5 wt% water and ~500 ppm sodium ions is dehydrated to below 1000 ppm in the membrane separation module.

[0032] (5) The waste liquid generated by the membrane module enters the waste - water receiving tank after condensation.

[0033] (6) The product after dehydration treatment by the membrane module is cooled and then enters the product receiving tank.

[0034] The durability test shows that the efficiency of the membrane module decreases by 0.35% after 240 h.

[0035] Example 2

[0036] The system purifies the N - methylpyrrolidone (NMP) - water organic solution as follows:

[0037] An NMP - aqueous solution containing 5 wt% water and 800 ppm amine and amide impurities is used as the raw material.

[0038] (1) The NMP aqueous solution containing 5 wt% water, 800 ppm amine and amide impurities enters a centrifugal pump to obtain mechanical energy and static pressure energy, and then enters a filter to remove large particle impurities and a small part of other impurities;

[0039] (2) After the NMP aqueous solution containing 5 wt% water, 800 ppm amine and amide impurities removes large particle impurities and a small part of other impurities, it enters an adsorber (the functional layer of the adsorber is zeolite molecular sieve) to reduce the concentration of amine and amide impurities to less than 10 ppm.

[0040] (3) The NMP aqueous solution containing 5 wt% water, 800 ppm amine and amide impurities is heated to a specific temperature in a heat exchanger after the concentration of amine and amide impurities in the adsorber is reduced to less than 10 ppm, and then enters a membrane module for dehydration;

[0041] (4) The NMP aqueous solution containing 5 wt% water, 800 ppm amine and amide impurities is dehydrated to less than 200 ppm in a membrane separation module.

[0042] (5) The waste liquid generated by the membrane module enters a waste water receiving tank after condensation.

[0043] (6) The product after dehydration treatment by the membrane module is cooled and then enters a product receiving tank.

[0044] The durability test shows that the efficiency of the membrane module decreases by 0.53% after 240 h.

[0045] Example 3

[0046] The system purifies a tetrahydrofuran water organic solution as follows:

[0047] A tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is used as the raw material.

[0048] (1) The tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol enters a centrifugal pump to obtain mechanical energy and static pressure energy, and then enters a filter to remove large particle impurities and a small part of other impurities;

[0049] (2) After the tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol removes large particle impurities and a small part of other impurities, it enters an adsorber (the functional layer of the adsorber is zeolite molecular sieve) to reduce ethylene glycol to less than 100 ppm.

[0050] (3) After the concentration of impurities in the tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is reduced in the adsorber, it is heated to a specific temperature in a heat exchanger and then enters a membrane module for dehydration;

[0051] (4) The tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is dehydrated to less than 100 ppm in a membrane separation module.

[0052] (5) The waste liquid generated by the membrane module enters the waste water receiving tank after condensation.

[0053] (6) The product after dehydration treatment of the membrane module enters the product receiving tank after cooling down.

[0054] The durability test shows that the efficiency of the membrane module decreases by 0.43% after 240 h.

[0055] Comparative Example 1

[0056] The system purifies the ethanol-water organic solution as follows:

[0057] An ethanol aqueous solution containing 5 wt% water and 1000 ppm sodium ions is used as the raw material.

[0058] (1) An ethanol aqueous solution containing 5 wt% water and ~500 ppm sodium ions is heated to a specific temperature by a heat exchanger and enters the membrane module for dehydration;

[0059] (2) The ethanol aqueous solution containing 5 wt% water and ~500 ppm sodium ions is dehydrated to below 1000 ppm in the membrane separation module.

[0060] (3) The waste liquid generated by the membrane module enters the waste water receiving tank after condensation.

[0061] (4) The product after dehydration treatment of the membrane module enters the product receiving tank after cooling down.

[0062] The durability test shows that the efficiency of the membrane module decreases by 15.4% after 240 h.

[0063] Comparative Example 2

[0064] The system purifies the N-methylpyrrolidone (NMP)-water organic solution as follows:

[0065] An NMP aqueous solution containing 5 wt% water and 800 ppm amine and amide impurities is used as the raw material.

[0066] (1) An NMP aqueous solution containing 5 wt% water and 800 ppm amine and amide impurities is heated to a specific temperature by a heat exchanger and enters the membrane module for dehydration;

[0067] (2) The NMP aqueous solution containing 5 wt% water and 800 ppm amine and amide impurities is dehydrated to below 200 ppm in the membrane separation module.

[0068] (3) The waste liquid generated by the membrane module enters the waste water receiving tank after condensation.

[0069] (4) The product after dehydration treatment of the membrane module enters the product receiving tank after cooling down.

[0070] The durability test shows that the efficiency of the membrane module decreases by 25.3% after 240 h.

[0071] Comparative Example 3

[0072] The system purifies the tetrahydrofuran - water organic solution as follows:

[0073] A tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is used as the raw material.

[0074] (1) The tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is heated to a specific temperature by a heat exchanger and enters the membrane module for dehydration.

[0075] (2) The tetrahydrofuran aqueous solution containing 5 wt% water and 3000 ppm ethylene glycol is dehydrated to less than 100 ppm in the membrane separation module.

[0076] (3) The waste liquid generated by the membrane module enters the waste water receiving tank after condensation.

[0077] (4) The product after dehydration treatment by the membrane module is cooled and then enters the product receiving tank.

[0078] The durability test shows that the efficiency of the membrane module decreases by 17.6% after 240 h.

[0079] The data of the decrease in the separation efficiency of the molecular sieve membranes obtained in the examples and comparative examples show that under the same feed conditions, operating pressure and temperature, the coupling of adsorption filtration and molecular sieve membrane dehydration process effectively reduces the loss caused by the membrane separation efficiency. In addition, the actual production requirements can be met by flexibly controlling the materials and quantities of the filtration and adsorption functional layers.

Claims

1. An organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration, characterized in that, It includes the following steps: The dehydration system includes a centrifugal pump, Filter A, Filter B, Adsorber A, Adsorber B, a heat exchanger, a membrane separation unit, a vacuum assembly, a condenser, a buffer tank, a waste water receiving tank, a product receiving tank, etc. The organic solution is given mechanical energy and static pressure energy by the centrifugal pump and then enters the filter to remove large particle impurities and a small part of other impurities. After the organic solution removes large particle impurities and a small part of other impurities, it enters the adsorber to remove other specific impurities (metal ions, high-viscosity components, easily polymerizable components, etc.). After the organic solution removes specific impurities in the adsorber, it is heated to a specific temperature by the heat exchanger and enters the membrane module for dehydration. The organic solution is dehydrated to a specific water content in the membrane separation module. The waste liquid generated by the membrane module enters the waste water receiving tank after condensation. The product after dehydration treatment by the membrane module is cooled and then enters the product receiving tank.

2. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 1, wherein: The organic solution is an aqueous solution of methanol, ethanol, propanol, isopropanol (IPA), tetrahydrofuran, acetone, N-methylpyrrolidone (NMP), dimethyl carbonate, ethyl methyl carbonate, ether, dimethyl sulfoxide, etc. with good water solubility.

3. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 1, characterized in that: An interlock control system is provided for the flow rate, pressure, and temperature control between the devices.

4. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 1, wherein: The membrane module includes a supporting heat exchanger, a membrane separator, a vacuum assembly, a storage tank, etc.

5. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 1, characterized in that: Filter A, Filter B, Adsorber A, and Adsorber B can be placed after the heat exchanger and before the membrane module.

6. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 1, characterized in that: Only one of the filtration module and the adsorption module can be introduced into the system, or both modules can be introduced.

7. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 6, characterized in that: The functional layers of Filter A and Filter B modules are paper filters, chemical fiber filters, metal mesh filters, metal powder sintered filters, PP filters, wire gap filters, activated carbon filters, etc.

8. The organic solvent dehydration system and method based on the coupling of adsorption filtration and molecular sieve membrane dehydration according to claim 6, characterized in that: The functional layers of Adsorber A and Adsorber B modules are zeolite molecular sieves, activated carbon, alumina, metal-organic frameworks (MOF), polyacrylamide, etc.

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