阅读说明：本技术 一种改性多孔膜材料、制备方法以及二氧化碳的液膜分离方法 (Modified porous membrane material, preparation method and liquid membrane separation method of carbon dioxide ) 是由 范益群 徐鹏 邱鸣慧 符开云 陈献富 孔祥力 龚大为 于 2019-08-21 设计创作，主要内容包括：本发明涉及一种用于增强液膜分离二氧化碳的膜改性方法,该方法是将含有胺类基团的有机物接枝在膜材料上,然后在多孔膜的孔道内负载水制得支撑液膜用于二氧化碳的混合气分离实验。本发明通过化学接枝反应引入胺类基团,使水作为膜液时具有一定的碱性,相比较于碱性溶液作为膜液,可以避免有效碱性物质的流失,同时二氧化碳的渗透通量也得到了提高。(The invention relates to a membrane modification method for enhancing carbon dioxide separation of a liquid membrane. The invention introduces amine groups through chemical grafting reaction, so that water has certain alkalinity as membrane liquid, and compared with alkaline solution as membrane liquid, the invention can avoid loss of effective alkaline substances and improve the permeation flux of carbon dioxide.)

1. The modified porous membrane material is characterized in that the membrane material is an inorganic porous material, and amine-containing groups are modified in pore channels of the membrane material.

2. The modified porous membrane material of claim 1, wherein in one embodiment, the amine group is one of a primary amine, a secondary amine, or a tertiary amine group.

3. The modified porous membrane material of claim 1, wherein in one embodiment, the inorganic porous material is porous alumina, porous titania, porous zirconia, or porous silica.

4. The modified porous membrane material of claim 1, wherein in one embodiment, the membrane material has an average pore size of 1 to 200 nm; in one embodiment, the membrane material geometry is flat or tubular.

5. The method for preparing the modified porous membrane material of claim 1, comprising the steps of: dissolving a silane coupling agent containing amine groups in an organic solvent to serve as a modifier; and immersing the porous membrane material in a modifier for grafting reaction, and after the reaction is finished, cleaning and drying to obtain the modified porous membrane material.

6. The method of claim 5, wherein in one embodiment, the silane coupling agent containing an amine-based group: selected from, for example, N-dimethyl-3-aminopropyltrimethoxysilane, (3-aminopropyl) trimethoxysilane; the organic solvent is at least one of ethanol, acetone, Dimethylacetamide (DMAC) and Tetrahydrofuran (THF).

7. The preparation method of the modified porous membrane material according to claim 5, wherein the reaction conditions are that the temperature is 20-40 ℃ and the reaction time is 1-24 h.

8. A method for liquid membrane separation of carbon dioxide, comprising the steps of: water is used as a solvent and loaded in the pore channels of the modified porous membrane material to form a liquid membrane; then contacting with the mixed gas containing carbon dioxide to make the carbon dioxide permeate the film layer.

9. The method for liquid membrane separation of carbon dioxide according to claim 8, wherein the carbon dioxide-containing gas mixture is CO₂And is at least N₂、CH₄、H₂、O₂He, and CO gas.

10. Use of the modified porous membrane material of claim 1 for increasing the separation factor or permeate flux in a liquid membrane separation process of carbon dioxide.

Technical Field

The invention belongs to the modification of a membrane material, and particularly relates to amination modification of a membrane material supporting a liquid membrane and application of the membrane material in enhancing carbon dioxide separation.

Background

In recent years, the greenhouse effect has been one of the most concerned environmental problems, and the main source of the greenhouse effect is CO₂This is mainly discharged from power plants, steel plants, chemical plants, and the like. In view of preventing global warming, development of a technology for efficiently collecting and recovering carbon dioxide is urgent. In addition to this, with CH₄The main component of natural gas production also contains CO₂The recovery of CO from natural gas is required₂Prevention of CO₂And corrosion of gas pipes during gas delivery. In addition, there are many substances containing CO₂And requires the removal of CO₂The system to be treated.

At present, CO₂The separation and capture mainly comprises low-temperature liquefaction separation, absorbent separation, adsorption capture, membrane separation and the like. Wherein CO is₂The amine chemical absorption method is mature and has already realized industrial application, but the alcoholamines absorb CO₂Then, the temperature is required to be increased for desorption, and the excessive temperature can cause the degradation (CN 103638780A) of the absorbent, thereby reducing the regeneration degree and the circulation rate of the absorbent. In addition, the energy consumption of the gas desorption tower accounts for the whole CO₂The capture cost is ~ 75%, and the strong corrosion of the amine solvent to the equipment seriously reduces the CO₂The trapping economy and the amine absorption method are difficult to technically break through further due to the characteristics of the amine absorption method; although the principle of low-temperature liquefaction separation is simpler, the required energy consumption is very large, the cost is higher, and the scale of the used device is larger; adsorption processes require pressure, temperature, or bothThe steps required for continuous use are relatively complicated; membrane separation is a relatively new separation technique, but the CO obtained₂The "Robeson ceiling" which is limited in purity and difficult to break through, i.e. the membrane material cannot achieve both a higher permeation rate and a high selectivity.

At present, the supported liquid membrane has a good breakthrough in realizing high selectivity and high permeability, so that researches on the application of the technology in gas separation are gradually valued by researchers. Ionic liquids due to their higher CO₂The dissolution selectivity and the self-volatility are well applied to the supported liquid membrane, but the surface tension is low, so that the requirements on the pore size distribution and the size of the membrane are high, and the membrane-crossing pressure difference cannot be borne, so that the ionic liquid is easy to lose, secondary pollution is caused to the environment, and the ionic liquid is high in price and causes certain economic loss.

In addition, when the porous membrane self-supporting liquid membrane separation method using the ionic liquid in the prior art is adopted, the steps are complicated in the actual operation process. After the separation equipment is replaced by a use site, the liquid membrane needs to be prepared again, so that the operation steps are increased, and the problems of raw material acquisition and the like exist.

Disclosure of Invention

The invention aims to solve the problem of loss of a membrane liquid of a supported liquid membrane and simultaneously reserve the high effect of carbon dioxide of an ionic liquid, and provides a membrane material amination modification method for enhancing the separation of carbon dioxide from a water-supported liquid membrane.

In a first aspect of the present invention, there is provided:

a modified porous membrane material is an inorganic porous material, and amine-containing groups are modified in pore channels of the membrane material.

In one embodiment, the amine group is one containing a primary, secondary or tertiary amine group.

In one embodiment, the inorganic porous material is porous alumina, porous titania, porous zirconia, or porous silica.

In one embodiment, the average pore diameter of the membrane material is 1-200 nm.

In one embodiment, the membrane material geometry is flat or tubular.

In a second aspect of the present invention, there is provided:

the preparation method of the modified porous membrane material comprises the following steps:

dissolving a silane coupling agent containing amine groups in an organic solvent to serve as a modifier; and immersing the porous membrane material in a modifier for grafting reaction, and after the reaction is finished, cleaning and drying to obtain the modified porous membrane material.

In one embodiment, the amine-based group-containing silane coupling agent: selected from, for example, N-dimethyl-3-aminopropyltrimethoxysilane, (3-aminopropyl) trimethoxysilane and the like.

In one embodiment, the organic solvent is at least one of ethanol, acetone, Dimethylacetamide (DMAC), and Tetrahydrofuran (THF).

In one embodiment, the reaction is carried out at a temperature of 20-40 ℃ for 1-24 h.

In a third aspect of the present invention, there is provided:

a method for liquid membrane separation of carbon dioxide, comprising the steps of:

water is used as a solvent and loaded in the pore channels of the modified porous membrane material to form a liquid membrane; then contacting with the mixed gas containing carbon dioxide to make the carbon dioxide permeate the film layer.

In one embodiment, the carbon dioxide-containing gas mixture is CO₂And is at least N₂、CH₄、H₂、O₂And He, CO, etc.

In a fourth aspect of the present invention, there is provided:

the modified porous membrane material is applied to improving the separation factor or the permeation flux in the liquid membrane separation process of carbon dioxide.

Advantageous effects

In the invention, the amine group is modified on the surface of the porous ceramic material, so that the amine group can be fixed on the surface of the material, and the effect of separating carbon dioxide by a liquid film can be realized by utilizing the structure.

In the invention, the high molecular functional material grafted with amine groups on the membrane material can meet the requirements of selective separation and permeation enhancement of the liquid membrane and can avoid the problem of membrane liquid loss caused by using ionic liquid.

The invention carries out amination modification on the porous membrane material, can graft the carrier for enhancing transmission on the surface of the membrane in an immobilized form, thus avoiding the loss of effective alkaline substances, and the membrane solvent adopted in the experiment is environment-friendly water. In addition, under the condition that the membrane liquid runs off, the liquid membrane can be easily repaired under the condition of carbon dioxide mixed gas containing water vapor by utilizing the hydrophilic property and the pore structure size of the membrane material, so that the stability of the supported liquid membrane can be improved, and the operation is convenient.

By adopting the method, the amine groups are directly immobilized in the porous material, when the separation equipment needs to be replaced by a use place, the equipment can be directly moved, a complex liquid film does not need to be prepared again, simple and easily-obtained water is directly adopted as a medium, and the use convenience of the device is greatly improved.

Drawings

FIG. 1 is an infrared spectrum of an aminated modified porous membrane material.

FIG. 2 is a graph showing the effect of a water supported liquid membrane prepared from a porous membrane material before and after amination modification on gas permeability in a carbon dioxide separation system.

FIG. 3 is a graph of the effect of temperature on carbon dioxide permeability for an un-aminated modified porous membrane.

Detailed Description

The technical scheme of the invention is that a silane coupling agent containing amine groups is dripped into an organic solvent to be dissolved to prepare a modified solution, a porous membrane material is immersed in the modified solution to react, and the porous membrane material is cleaned and dried after the reaction is finished to obtain the membrane material rich in amine groups. Then under the action of surface tension, water is loaded in the membrane pore channels, and the prepared supported liquid membrane is used for separating carbon dioxide gas mixture.

The method for modifying the supporting material is simple and easy to implement, can avoid the problem of membrane liquid loss (having higher requirement on aperture) caused by using the ionic liquid, and can improve the selective separability of the water-supported liquid membrane to carbon dioxide by introducing the amine group.

The membrane liquid used by the water-supported liquid membrane prepared by the invention is green solvent water, has no pollution to the environment and is cheap and easy to obtain.

The porous membrane material adopted by the invention has hydrophilicity, so that water vapor can be conveniently added into carbon dioxide mixed gas, and the liquid membrane can be repaired through capillary condensation.

The modified porous membrane material provided by the invention has the advantages that the inside of the pore channel of the membrane material is modified with amine-containing groups.

In one embodiment, the amine group is one containing a primary, secondary or tertiary amine group.

In one embodiment, the material of the membrane material is an inorganic porous membrane material or a polymer porous membrane material.

In one embodiment, the inorganic porous material is porous alumina, porous titania, porous zirconia, or porous silica.

In one embodiment, the average pore diameter of the membrane material is 1-200 nm.

In one embodiment, the membrane material geometry is flat or tubular.

The preparation method of the modified porous membrane material comprises the following steps:

dissolving a silane coupling agent containing amine groups in an organic solvent to serve as a modifier; and immersing the porous membrane material in a modifier for grafting reaction, and after the reaction is finished, cleaning and drying to obtain the modified porous membrane material.

In one embodiment, the amine-based group-containing silane coupling agent: selected from, for example, N-dimethyl-3-aminopropyltrimethoxysilane, (3-aminopropyl) trimethoxysilane and the like.

In one embodiment, the organic solvent is at least one of ethanol, acetone, Dimethylacetamide (DMAC), and Tetrahydrofuran (THF).

In one embodiment, the reaction is carried out at a temperature of 20-40 ℃ for 1-24 h.