CN110038448B

CN110038448B - Liquid-permeable and gas-barrier fluid composite membrane system

Info

Publication number: CN110038448B
Application number: CN201910461291.7A
Authority: CN
Inventors: 侯旭; 刘静; 盛智芝; 雷奕; 吕薇
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2021-03-23
Anticipated expiration: 2039-05-30
Also published as: CN110038448A

Abstract

The invention discloses a high-efficiency liquid-gas-barrier fluid composite membrane system, which comprises a solid porous membrane and functional fluid, wherein the functional fluid infiltrates the solid porous membrane to form a fluid gate control channel through which transported fluid can pass, and the liquid-gas-barrier system with the separation efficiency up to 100% can be obtained by transporting the liquid at the same flow rate more easily than the transported gas, and has wide application prospect in the fields of environment, energy, chemical reactors, medicine, aerospace and the like. The method effectively solves the problems that the traditional membrane separation method cannot realize the functions of liquid permeation and gas barrier, is easy to pollute, has short service life, low separation efficiency, high investment cost and the like, utilizes a fluid composite membrane system to carry out gas-liquid separation, and is a novel microporous membrane gas-liquid separation technology which has low investment cost, high efficiency separation and easy industrial popularization.

Description

Liquid-permeable and gas-barrier fluid composite membrane system

Technical Field

The invention relates to the technical field of microporous membrane separation, in particular to a liquid-permeable and gas-barrier fluid composite membrane system.

Background

The film science has very important significance in solving the problems in the fields of energy, water resources, environment, biomedicine, ships and submarines, aerospace and the like faced by the contemporary human, and the film material also plays an important role in the life of people, for example: sewage treatment and air purification in daily life; multi-phase separation in chemical production; ion monitoring in analytical testing, and the like. The rapid development of the society has sharply increased requirements on the functional application of the materials and the durability of the materials, and also puts higher requirements on various properties of the film materials.

At present, the separation mechanisms of the common gas-liquid separation technology mainly comprise a gravity settling type, a filtration separation type, an inertia collision type, a centrifugal separation type, diffusion and the like, and a plurality of practical gas-liquid separators are developed according to the mechanisms, however, most of the devices are large and complex, the energy consumption is high, and the microporous membrane is adopted for gas-liquid separation, so that the complexity of the system can be reduced, and the parasitic energy consumption can be reduced. As is well known, gas molecules are small and therefore pass through membranes more easily than liquids, and the function of passing liquids through while blocking gases (i.e., liquid-permeable gas barriers) is mostly difficult to achieve with common membrane separation methods. The hydrophilic membrane is used for realizing the passive water drainage and air resistance functions, however, in the industrial aspect, one of the biggest problems of the filtering membrane is the pollution problem, the blockage of the pore channel of the filtering membrane can not only cause the reduction of the filtering efficiency, but also can cause secondary pollution to the filtered substances, the reduction of the separation efficiency is caused, the gas-liquid separation effect is influenced, and the separation cost is increased.

The fluid composite membrane system enables the transportation of substances to be carried out on the liquid surface by compounding the gating fluid and the microporous membrane, overcomes the defect of membrane pollution caused by liquid-solid contact in the separation of the traditional microporous membrane, and has excellent anti-fouling performance, thereby greatly improving the production efficiency and reducing the investment scale and the operation cost. The fluid composite membrane system can be widely applied to various aspects such as environment, energy, chemical reactors, medicines and the like, in addition, as the liquid discharge and gas resistance of the system are not dependent on gravity as a driving force, the system can meet the requirements of China space stations and manned deep space detectors on gas-liquid separation technology, and the research of the space gas-liquid separation technology undoubtedly lays a foundation for the development of future aerospace industry in China.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the fluid composite membrane system which can enable liquid to easily permeate to block gas is obtained by compounding the porous membrane with the functional fluid and adjusting parameters such as membrane structure, pore size, flow rate of transported fluid and the like, and the separation efficiency is effectively improved to meet the application requirement of gas-liquid separation of the microporous membrane.

The invention is based on the liquid gating technology, compounds the solid porous membrane with the functional fluid to construct a fluid composite membrane system, obtains a liquid-permeable gas-barrier system with the separation efficiency of 100 percent, and has wide application prospect in the fields of environment, energy, chemical reactors, medicine, aerospace and the like. The method effectively solves the problems that the traditional membrane separation method cannot realize the functions of liquid permeation and gas barrier, is easy to pollute, has short service life, low separation efficiency, high investment cost and the like, utilizes a fluid composite membrane system to carry out gas-liquid separation, and is a novel microporous membrane gas-liquid separation technology which has low investment cost, high efficiency separation and easy industrial popularization.

It is an object of the present invention to provide a liquid-permeable, gas-barrier fluid composite membrane system in order to solve the above-mentioned problems.

The invention realizes the purpose through the following technical scheme:

the invention comprises a solid porous membrane and a functional fluid, wherein the functional fluid infiltrates the solid porous membrane to form a fluid-gated channel for transporting fluid, and the fluid-gated channel is easier to pass through than a gas when the liquid is transported at the same flow rate.

The wettability of the functional fluid and the solid porous membrane is greater than the wettability of the transport fluid and the solid porous membrane.

The functional fluid is immiscible with the transport fluid.

The solid porous membrane structure is a woven mesh structure.

The solid porous membrane with the knitted reticular structure is made of a metal material or a polymer net membrane.

The transport fluid is a gas single phase or a liquid single phase or a mixture of gas and liquid phases.

The liquid is easier to pass through the fluid gate control channel than gas when being transported at the same flow rate, and the liquid transporting method is characterized in that the transported liquid is difficult to obtain through a pressure test when passing through the fluid gate control channel, and the membrane passing is easy to pass if the membrane passing pressure is lower.

The invention has the beneficial effects that:

compared with the prior art, the invention utilizes a simple method to construct a fluid composite membrane system which is easy for industrial scale production, realizes the function of no excessive liquid-gas passing (namely, liquid permeability and gas resistance) which is difficult to realize by the traditional membrane, can realize 100 percent high-efficiency separation of gas and liquid, has effective stain resistance, can be recycled, prolongs the service life, reduces the actual operation cost, and can fully meet the application requirements of various fields of energy, environment, medicine, aerospace and the like on microporous membrane separation technology.

Drawings

Figure 1 is a schematic diagram of a fluid composite membrane system of example 1;

FIG. 2 is an SEM photograph of the stainless steel net used in example 1;

FIG. 3 is a gas-liquid pressure test chart in example 1;

FIG. 4 is a plan view of a gas-liquid separating apparatus according to example 1;

FIG. 5 is a diagram of the embodiment 1 for realizing the complete gas-liquid separation;

FIG. 6 is a diagram showing the structure of the gas-liquid separator of example 2 for separating the tail gas of a PEM fuel cell.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

example 1:

referring to fig. 1, the high performance liquid-permeable, gas-barrier, fluid composite membrane system of the present invention comprises a solid porous membrane 1 and a functional fluid 2, wherein the functional fluid 2 infiltrates the solid porous membrane 1 to form a fluid-gated channel through which transport fluid 3 can pass, wherein the fluid-gated channel is easier to pass than the transport gas when transporting liquid at the same flow rate. The wettability of the functional fluid 2 and the solid porous membrane 1 is greater than the wettability of the transport fluid 3 and the solid porous membrane 1, and the functional fluid 2 and the transport fluid are immiscible. When the transport fluid 3 is a gas-liquid mixture, only liquid can pass through the composite membrane, and gas cannot pass through the composite membrane.

The solid porous membrane is made of a stainless steel mesh with a woven mesh structure, the aperture of the stainless steel mesh is 20 micrometers, the thickness of the stainless steel mesh is 180 micrometers, the diameter of the stainless steel mesh is 25 mm, the functional fluid is made of simethicone, the viscosity of the simethicone is 500 cP, the simethicone infiltrates the stainless steel mesh to form a fluid gate control channel through which transport fluid can pass, and the transport fluid is air, ultrapure water or a mixture of the air and the ultrapure water. The wettability of the dimethyl silicon oil and the stainless steel mesh is larger than that of the transport fluid and the stainless steel mesh, and the dimethyl silicon oil and the transport fluid are immiscible. The high-efficiency liquid-gas-barrier fluid composite membrane system is packaged in a sealed outer shell, and pressure tests are carried out at the flow rate of 1 mL/min, and it can be seen from figure 3 that the critical pressures of air and ultrapure water passing through the membrane are 1870 Pa and 860 Pa respectively, so that ultrapure water is easier to pass through a fluid gate control channel than air in the process of transporting ultrapure water.

Referring to fig. 4, the liquid-and gas-barrier fluid composite membrane system provided in this example was used as a separation membrane, and was sealed in a gas-liquid separation chamber. The gas-liquid separation cavity comprises a clamping device 3 and a sealing material 4, the clamping device 3 comprises a left clamping piece 31 and a right clamping piece 32, a cavity is formed between the clamping device 3 and the sealing material 4, the solid porous membrane 1 and the functional fluid 2 are arranged in the cavity, the cavity further comprises a fluid separation channel 5 on the left side of the solid porous membrane 1, the fluid separation channel 5 is placed in the horizontal direction, and the separation process does not depend on the action of gravity. And a gas-liquid mixed fluid conveying inlet 6 and a liquid separation outlet 7 which are respectively positioned at two sides of the fluid gate control channel and a gas conveying outlet 8 which is positioned at the same side of the solid porous membrane 1 as the fluid conveying inlet 6 are arranged at two sides of the cavity.

Fig. 5 is a diagram showing the results of gas-liquid separation using the fluid composite membrane system with liquid and gas barriers provided in this embodiment, where the gas-liquid separation efficiency can reach 100%, and high-efficiency gas-liquid separation can be achieved.

Example 2:

as shown in fig. 6: to further illustrate the application of the high performance liquid gas barrier fluid composite membrane system, referring to fig. 6, the gas-liquid separation device (in dashed box 1) shown in fig. 4 is combined with a Proton Exchange Membrane Fuel Cell (PEMFC) (in dashed box 2) to be used as a cathode to generate O₂/H₂And O tail gas is separated, so that water is condensed at the inlet end of the fluid composite Membrane system and then is discharged from the outlet of the rear end through the fluid composite Membrane, oxygen is blocked at the front end of the fluid composite Membrane and is introduced into the air inlet of the cathode of the PEMFC from a pipeline to be recycled as a reaction raw material, the utilization rate of the raw material is improved, the use cost of the PEMFC is saved, and a Membrane Electrode Assembly (MEA) is arranged between the anode and the cathode.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A gas-liquid separation apparatus employing as a separation membrane a liquid-gas-barrier fluid composite membrane system comprising a solid porous membrane and a functional fluid, the functional fluid infiltrating the solid porous membrane to form a fluid-gated channel through which transport fluid passes, transport fluid passing more readily through the fluid-gated channel than transport gas at the same flow rate, characterized in that: the solid porous membrane structure is a woven net structure, and the solid porous membrane of the woven net structure is made of a metal material or a polymer net membrane;

the gas-liquid separation device comprises a gas-liquid separation cavity, the gas-liquid separation cavity comprises a clamping device and a sealing material, the clamping device comprises a left clamping piece and a right clamping piece, a cavity is formed between the clamping device and the sealing material, the solid porous membrane and the functional fluid are arranged in the cavity, the cavity also comprises a fluid separation channel on the left side of the solid porous membrane, the fluid separation channel is placed in the horizontal direction, and the separation process does not depend on the action of gravity; a gas-liquid mixed fluid conveying inlet and a liquid separation outlet which are respectively positioned at two sides of the fluid gate control channel and a gas conveying outlet which is positioned at the same side of the solid porous membrane with the fluid conveying inlet are arranged at two sides of the cavity;

the wettability of the functional fluid and the solid porous membrane is greater than that of the transport fluid and the solid porous membrane, the functional fluid and the transport fluid are immiscible, and the transport fluid is a mixture of a gas phase and a liquid phase.

2. A gas-liquid separation apparatus according to claim 1, wherein the gas-liquid separation apparatus comprises a liquid-permeable gas-barrier fluid composite membrane system as a separation membrane, and further comprises: the difficulty of conveying fluid through the fluid gating channel is obtained through a pressure test, and the passing of the fluid is easy when the membrane pressure is low.