A CO2 treatment method and absorption device based on liquid organic amine

Abstract

The present invention relates to the technical field of positive pressure oxygen respirators, and in particular to a CO2 treatment method and absorption device based on liquid organic amines. The CO2 absorption device based on liquid organic amines provided by the present invention comprises a shell, an organic amine absorption liquid, a pipeline, and an air inlet located at the bottom of the shell box body and an air outlet located at the top of the shell box body; the organic amine absorption liquid is filled in the gap between the pipeline and the inner wall of the shell, the air inlet is connected to one end of the pipeline, the air outlet is connected to the other end of the pipeline, and a gas separation membrane is provided on the pipeline. The novel CO2 chemical treatment method and device proposed by the present invention based on the combined strategy of combining liquid organic amine absorbent and MOFs membrane can eliminate various adverse effects, improve treatment efficiency, and reduce the weight and volume of the CO2 absorption tank.

Description

Technical Field

[0001] The present invention relates to the technical field of positive pressure oxygen respirators, and in particular to a CO2 treatment method and absorption device based on liquid organic amine. Background Art

[0002] Positive pressure oxygen respirators are mainly used by mine rescuers or firefighters when they are engaged in disaster relief and handling accidents. They can also be used by specially trained personnel in defense, chemical, nuclear, petroleum, metallurgical tunnels and other departments in toxic, harmful and hypoxic environments. They are individual respiratory protective equipment. The CO2 content in the air does not exceed 0.04%, and the CO2 concentration exhaled by the human body is about 4%, and it will continue to accumulate in a closed environment. When the CO2 content is 1% to 2%, it will not cause significant changes in breathing conditions; when the CO2 content reaches 4% to 5%, it will cause tinnitus and temple throbbing; when the CO2 content reaches 8%, it will cause severe headaches and dizziness; when the CO2 content reaches 10%, it will cause people to lose consciousness or even die. Therefore, as an important component module in the isolated positive pressure oxygen respirator, the processing capacity of the CO2 absorption tank is directly related to the overall performance of the isolated positive pressure oxygen respirator.

[0003] At present, positive pressure oxygen respirators mainly use CO2 absorbents to treat CO2, and they are all solid alkaline substances, including lime and soda lime, usually in the form of spherical, hemispherical and cylindrical particles with uniform particle size. The CO2 absorbent is filled in a cylindrical tank with an elliptical cross-section, supported by porous plates above and below, and filled with sponge-like materials to reduce dust from entering the airbag or breathing passage. This structure and chemical absorbent have made important contributions to reducing casualties in emergency rescue.

[0004] However, the currently known isolated positive pressure oxygen respirators and the CO2 absorbents used, such as lime and soda lime, have the following disadvantages: (1) the absorbents are prone to react with CO2 in the air and become ineffective; (2) a large amount of heat is released during use, which has an adverse effect on subsequent human breathing and is prone to causing respiratory burns; (3) the absorbent replacement process is complicated; (4) alkaline dust is easily raised during use; (5) CO2 gas usually flows preferentially through the gaps between particles with smaller steric hindrance, forming a fixed airflow channel, resulting in some absorbents not functioning and reducing the overall absorption efficiency; (6 ) After carbon dioxide reacts with calcium lime or sodium lime, a dense salt layer will be formed on the surface, which makes the central calcium lime or sodium lime unable to contact with CO2 gas, resulting in low absorption efficiency; (7) In order to ensure the use time, the amount of CO2 absorbent is usually prepared to 10 to 20 times the theoretical amount, which not only causes a large amount of absorbent waste, but also increases the volume and weight of the absorption tank, increases the user's burden, and affects the user experience and rescue efficiency; (8) For safety reasons, no matter how long the respirator is used, the absorbent must be replaced before the next use, resulting in a high absorbent consumption. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a CO2 treatment method and absorption device based on liquid organic amine. The novel CO2 chemical treatment method and device proposed by the combination strategy based on the combination of liquid organic amine absorbent and MOFs membrane can eliminate various adverse effects, improve the treatment efficiency, and reduce the weight and volume of the CO2 absorption tank.

[0006] In a first aspect, the present invention provides a CO2 absorption device based on liquid organic amines, comprising: an outer shell, an organic amine absorption liquid, a pipeline, and an air inlet located at the bottom of the outer shell box body and an air outlet located at the top of the outer shell box body; the organic amine absorption liquid is filled in the gap between the pipeline and the inner wall of the outer shell, the air inlet is connected to one end of the pipeline, the air outlet is connected to the other end of the pipeline, and a gas separation membrane is provided on the pipeline.

[0007] Preferably, the pipeline is arranged with gas separation membranes and hard plastics at intervals; preferably, the gas separation membranes are embedded in the hard plastics.

[0008] Further preferably, the hard plastic is polyethylene, polystyrene, polystyrene or epoxy resin.

[0009] Preferably, the air inlet and the air outlet are provided with sealing joints; the air inlet is used to connect with the breathing mask pipeline, and the air outlet is used to connect with the airbag.

[0010] Preferably, the organic amine absorption liquid uses an organic amine containing chemical groups that are affinity to CO2 molecules, including hydroxyl, amino and carboxyl groups; the molecular weight of the organic amine is 41-382.

[0011] Preferably, the organic amine absorption liquid is a two-phase system of diethylenetriamine and pentamethyldiethylenetriamine, and the molar ratio of diethylenetriamine to pentamethyldiethylenetriamine is 1 to 10:1.

[0012] Further preferably, the gas separation membrane is a MOFs membrane; the selectivity of the gas separation membrane to CO2 gas is ≥95%, and the MOFs membrane is one or more of a polyamide filter membrane, a polysulfone filter membrane, and a polyether polyketone filter membrane.

[0013] Further preferably, the pipe is spiral, the outer diameter of the spiral pipe is 85% to 95% of the inner diameter of the shell, the outer diameter of the spiral pipe is 5 to 10 mm, the number of turns of the spiral pipe is 5 to 10 turns; and / or the width of the gap between the pipe and the shell is 4 to 10 mm.

[0014] Further preferably, the CO2 absorption device maintains the CO2 content below 0.5% within 40 minutes.

[0015] In a second aspect, the present invention provides a liquid organic amine-based CO2 treatment method, which uses the above-mentioned liquid organic amine-based CO2 absorption device.

[0016] The beneficial effects of the present invention are at least that: the present invention adopts a method of combining liquid organic amine with MOFs porous separation membrane, which avoids the problems of deterioration, high temperature, dust, cumbersome material replacement, fixed channels, dense salt layers, excessive material consumption, large volume, high weight, etc. compared with the traditional chemical treatment method of sodium lime and soda lime, and the side effects are suppressed, the absorption efficiency is improved, and it has the advantages of high safety, high reliability and environmental friendliness. In addition, the consumption of liquid organic amine and separation membrane is small, which reduces the weight and volume of the CO2 absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a novel carbon dioxide absorber based on liquid organic amine provided in an embodiment of the present invention;

[0019] Figure 2A cross section of a novel carbon dioxide absorber based on liquid organic amine provided in an embodiment of the present invention;

[0020] Figure 3 Comparison of the absorption capacity of the organic amine-based carbon dioxide absorber provided in the embodiment of the present invention and the traditional absorber;

[0021] Among them, 1-housing; 2-air inlet; 3-air outlet; 4-gap; 5-pipeline; 6-gas separation membrane; 7-hard plastic. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] If no specific technology or conditions are specified in the embodiments of the present invention, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the devices, instruments, reagents, etc. is not specified, they are all conventional products that can be purchased through regular channels. The raw materials used in the present invention can be easily purchased in the domestic product market.

[0024] In the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] An embodiment of the present invention provides a CO2 absorption device based on liquid organic amines, comprising: an outer shell, an organic amine absorption liquid, a pipeline, and an air inlet located at the bottom of the outer shell box body and an air outlet located at the top of the outer shell box body; the organic amine absorption liquid is filled in the gap between the pipeline and the inner wall of the outer shell, the air inlet is connected to one end of the pipeline, the air outlet is connected to the other end of the pipeline, and a gas separation membrane is provided on the pipeline.

[0027] In the embodiment of the present invention, the organic amine method for capturing CO2 has the advantages of fast absorption speed, large absorption amount, low cost, and recyclable absorbent. The use of organic amine to replace lime and soda lime is based on the following technical principles: (1) Liquid organic amine is a continuous flow liquid substance, and the filling operation is very convenient. In addition, there is no alkaline dust problem and no pores. The proportion of failure caused by reaction with CO2 in the air is very low; (2) The alkalinity of organic amine is weaker than that of lime and soda lime, so the heat generated by the reaction with CO2 is relatively small; (3) When liquid organic amine reacts with CO2, CO2 enters the organic amine solution in a diffusion manner and undergoes intermolecular chemical reaction. There is no fixed channel and no dense salt layer, and the efficiency is very high; (4) Liquid organic amine has high fluidity and can react with CO2 almost according to the stoichiometric ratio. Therefore, the demand for CO2 absorbent is greatly reduced, which is beneficial to reducing the volume and weight of the absorption tank; (5) Compared with solid granular lime and soda lime, liquid organic amine has a relatively small consumption due to its low actual demand. The present invention uses MOFs porous membrane for efficient separation of CO2-containing gas, and has high selectivity and adsorption characteristics. In particular, the organic amine absorption liquid is combined with the MOFs porous separation membrane, and the CO2 obtained through the MOFs porous separation membrane reacts with the organic amine absorption liquid in a flowing state, which can not only effectively avoid bubbling, but also improve the absorption efficiency. Compared with the existing method, the present invention adopts a method of combining liquid organic amine with MOFs porous separation membrane, and the side effects are suppressed, and the absorption efficiency, weight and volume are optimized.

[0028] As a preferred embodiment, the pipeline is arranged with gas separation membranes and hard plastics at intervals; preferably, the gas separation membranes are embedded in the hard plastics.

[0029] In a further preferred embodiment, the hard plastic is polyethylene, polystyrene, polystyrene or epoxy resin.

[0030] In the present invention, when the CO2 absorption device is used, the gas exhaled by the human body slowly passes through the spiral catheter from bottom to top through the air inlet. During this process, the carbon dioxide in the mixed gas will pass through the membrane and react with the organic amine solution to produce a dual effect of membrane absorption and chemical absorption. At the same time, due to the chemical reaction, osmotic pressure will be formed inside and outside the membrane during the absorption process, which helps the carbon dioxide to pass through the membrane and continuously react with the organic amine. The remaining gas after the absorption process flows out from the upper outlet and enters the air bag.

[0031] As a preferred embodiment, the air inlet and the air outlet are provided with sealing joints; the air inlet is used to connect with the breathing mask pipeline, and the air outlet is used to connect with the airbag.

[0032] As a preferred embodiment, the organic amine absorption liquid adopts an organic amine containing chemical groups that are affinity to CO2 molecules, including hydroxyl, amino and carboxyl groups; the molecular weight of the organic amine is 41-382.

[0033] In a preferred embodiment, the organic amine absorption liquid is a two-phase system of diethylenetriamine and pentamethyldiethylenetriamine, and the molar ratio of diethylenetriamine to pentamethyldiethylenetriamine is 1 to 10:1.

[0034] In a further preferred embodiment, the gas separation membrane is a MOFs membrane; the selectivity of the gas separation membrane to CO2 gas is ≥95%, and the MOFs membrane is one or more of a polyamide filter membrane, a polysulfone filter membrane, and a polyether polyketone filter membrane.

[0035] In a further preferred embodiment, the pipe is spiral, the outer diameter of the spiral pipe is 85% to 95% of the inner diameter of the outer shell, the outer diameter of the spiral pipe is 5 to 10 mm, the number of turns of the spiral pipe is 5 to 10 turns; and / or the width of the gap between the pipe and the outer shell is 4 to 10 mm.

[0036] In a further preferred embodiment, the CO2 absorption device maintains the CO2 content below 0.5% within 40 minutes.

[0037] The embodiment of the present invention further provides a liquid organic amine-based CO2 treatment method, which uses the above-mentioned liquid organic amine-based CO2 absorption device.

[0038] The embodiment of the present invention designs liquid organic amines. Organic amines containing chemical groups that are affinity to CO2 molecules, such as hydroxyl, amino, and carboxyl, are preferably selected as the absorption liquid. On this basis, organic amines with low molecular weight are used to reduce the weight of the absorption tank. Liquid organic amines and CO2 molecules can react quickly within 1 second; at the same time, MOFs porous separation membranes are designed. MOFs membranes have a much higher selective absorption of CO2 gas than O2 and N2, and the selectivity should be ≥95%, and have a lower separation driving force for CO2 gas. The present invention also designs the structure, and adopts a suitable method to combine the liquid organic amine and the MOFs porous separation membrane together to better exert the synergistic effect of CO2 treatment without causing liquid seepage or leakage.

[0039] Example 1

[0040] The schematic diagram of the novel CO2 absorber provided in this embodiment is as follows Figure 1 As shown. The absorber device comprises a shell 1, an air inlet 2 located at the lower part of the shell box and an air outlet 3 located at the upper part of the shell box. The air inlet is connected to the internal pipe of the absorption tank. The internal pipe 5 of the absorption tank is spiral, and MOFs absorption membranes are arranged at a certain interval around the pipe. The organic amine absorption solution fills the gap 4 between the outside of the pipe and the inner wall of the absorption tank. Quick sealing joints are left at the air inlet 2 and the air outlet 3. When in use, the air inlet 2 only needs to be connected to the breathing mask pipeline, and the air outlet 3 needs to be connected to the rear air bag.

[0041] like Figure 2 The cross-sectional view is shown. The organic amine absorption solution is filled in the gap between the outside of the pipeline and the inner wall of the absorption tank. It can be seen from the cross-sectional view of the spiral conduit 5 in the figure that the conduit is arranged by gas separation membrane 6 and polyethylene hard plastic 7 at intervals. The gas separation membrane 6 is embedded in the hard plastic 6 to ensure sealing. When in use, the gas exhaled by the human body slowly passes through the spiral conduit 5 from bottom to top through the air inlet 2. During this process, the carbon dioxide in the mixed gas will pass through the gas separation membrane 6 and react with the organic amine solution to produce a dual effect of membrane absorption and chemical absorption. At the same time, due to the chemical reaction, osmotic pressure will be formed inside and outside the membrane during the absorption process, which helps carbon dioxide to pass through the membrane and continuously react with the organic amine. The remaining gas after absorption treatment flows out from the upper outlet 3 and enters the air bag.

[0042] The organic amine used in this embodiment is a two-phase system of diethylenetriamine and pentamethyldiethylenetriamine, mixed in a molar ratio of 4:1, and the MOFs absorption membrane used is a commercially available hollow fiber membrane (polyamide filter membrane). The new carbon dioxide absorber based on liquid organic amine provided in this embodiment can maintain the carbon dioxide content below 0.5% within 40 minutes ( Figure 3), compared with the case of using calcium lime and sodium lime as carbon dioxide absorption materials, the working time is extended by 1 times and the component weight is reduced by 60%.

[0043] Example 2

[0044] The structure of Example 1 is still used, except that the mixed solution of organic amine 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and glycerol (i.e., DBU-glycerol system) used has a weight ratio of m(DBU):m(glycerol)=3:2, and the MOFs absorption membrane used is a polyether polyketone membrane. The new carbon dioxide absorber based on liquid organic amine provided in this embodiment can maintain the carbon dioxide content below 0.5% within 50 minutes. Compared with the case where calcium lime and sodium lime are used as carbon dioxide absorption materials, the working time is extended by 1.5 times and the weight of the component is reduced by 50%.

[0045] Comparative Example 1

[0046] This comparative example provides a conventional absorber, which uses commercially available calcium hydroxide granules as absorbent to fill the conventional absorber. The novel carbon dioxide absorber based on liquid organic amine provided in Example 1 of the present invention can maintain the carbon dioxide content below 0.5% within 40 minutes, while the comparative example 1 can only maintain it for 20 minutes ( Figure 3 ), showing that the present invention has high efficiency.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A CO2 absorption device based on liquid organic amine, characterized in that: include: The invention relates to a shell, an organic amine absorption liquid, a pipeline, an air inlet at the bottom of the shell box body and an air outlet at the top of the shell box body; the organic amine absorption liquid is filled in the gap between the pipeline and the inner wall of the shell, the air inlet is connected to one end of the pipeline, the air outlet is connected to the other end of the pipeline, the pipeline is arranged by gas separation membrane and hard plastic at intervals; the gas separation membrane is embedded in the hard plastic; the organic amine absorption liquid is a two-phase system of diethylenetriamine and pentamethyldiethylenetriamine, the molar ratio of diethylenetriamine to pentamethyldiethylenetriamine is 1:1 ~10:1, or the organic amine absorption liquid is a mixed solution of organic amine DBU and glycerol; the gas separation membrane is an MOFs membrane, and the MOFs membrane is one or more of a polyamide filter membrane, a polysulfone filter membrane, and a polyether polyketone filter membrane; the pipeline is spiral, and the outer diameter of the spiral pipeline is 85%~95% of the inner diameter of the outer shell, the outer diameter of the spiral tube is 5~10mm, and the number of turns of the spiral tube is 5~10 turns; the width of the gap between the pipeline and the outer shell is 4~10mm; the CO2 absorption device maintains the CO2 content below 0.5% within 40 minutes.

2. The CO2 absorption device based on liquid organic amine according to claim 1, characterized in that: The hard plastic is polyethylene, polystyrene, polystyrene or epoxy resin.

3. The CO2 absorption device based on liquid organic amine according to claim 1, characterized in that: The air inlet and the air outlet are provided with sealing joints; the air inlet is used to connect with the breathing mask pipeline, and the air outlet is used to connect with the airbag.

4. The CO2 absorption device based on liquid organic amine according to any one of claims 1 to 3, characterized in that: The selectivity of the gas separation membrane to CO2 gas is ≥95%.

5. A CO2 treatment method based on liquid organic amine, characterized in that: A CO2 absorption device based on liquid organic amine as described in any one of claims 1 to 4 is used.

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