DE19639965A1 - Separation of components of a gas mixture through membranes - Google Patents

Abstract

Process for the separation of one or more gaseous components of a gas mixture by passing the mixture over a membrane consisting of a micro-porous layer which supports a "dense" layer in contact with a liquid absorbent. Also claimed is the equipment required for this process. Preferably a desorption process is carried out in a vessel identical to the absorption vessel by passing steam at least 110 deg C. into the gas space. The membrane materials must therefore withstand temperatures of about 150 deg C. The absorbed gas is then released and transported across the membrane. The support layer is made of micro-porous PTFE. The dense layer, having a thickness of about 1 mu m, is made of perfluorodioxol, namely a perfluorated ionomer layer.

Description

The invention relates generally to the field of gas absorption using so-called membrane contactors. In particular, the invention relates a method for separating one or more gaseous com components from a gas phase, also a process for desorbing a gas component absorbed by a liquid absorbent from this absorbent. Finally, the invention relates to a plant for separating a gaseous component from a gas phase.

The gas absorption with membrane contactors mentioned at the outset belongs to the general technical field of gas separation, that is the Ab separation of one or more gaseous components from one Gas phase.

A specific example of such a separation of a gas component the exhaust gas purification is from a gas phase, for example from Exhaust gases from a power plant or CO₂ from natural gas. Furthermore is removed with the help of "gas separation" SO₂ from exhaust gases or at least at least the proportion of SO₂ in these exhaust gases largely reduced.

In addition to the examples given above, processes for gas Use separation indirectly to B. the share of one or to increase several gas components in a gas phase, for example increase the percentage of oxygen in air by other ingredients such as B. CO₂, are selectively removed from the gas phase.

Another example is the dehumidification of gases separating water vapor from a gas.

The following description of the invention relates specifically to the Ab separate CO₂ from exhaust gases, although the expert sees that Invention is not limited to this particular field of application.  

A widely used process for gas separation ver uses so-called "packed columns", which are containers with one built-in packing bed, which for example from top to bottom flowed through by an absorption liquid and at the same time in the counter current, that is, from the bottom upwards through which the gas mixture flows from which a gas component is to be removed. In the area of Packing bed, the gas component to be separated reacts with the Ab sorption liquid and is discharged with it from the container. The gas escaping from the top of the container contains a reduced one Share of the gas component mentioned, ideally contains the above gas escaping from the container is the separated gas component practically no more.

Even today, these packed columns are still used for gas separation used; because due to long experience the professional world is with this Technology trusted.

Are disturbing in this gas separation with the aid of packed columns their high weight and large space requirements. Control of the separation process is relatively complex and difficult. In addition, the Erection of plants with packed columns whose considerable Against investment costs.

Recent research and development work in the field of Gas separation is directed towards the use of membranes. The gas separation using membranes can be roughly divided into Processes using so-called selective membranes, and Processes that use non-selective membranes.

Gas separation using so-called selective membranes is e.g. B. described in WO 90/15662. In the stream of a gas mixture a multilayer membrane is introduced, consisting of a about 200 microns thick, microporous support or support layer and an active one on the inflow side of the carrier layer  Layer. This active layer is a perfluorodioxole layer with a 1 µm thick. This active layer is a non-porous layer, also known as a "dense layer". The mechanism of gas separation is that the active layer for the various components of the gas mixture fed to the membrane on the high pressure side is differently permeable. The through the membrane After gas permeation, the gas molecules pass through the active layer relatively quickly through the microporous carrier layer. A special An advantage over the packed columns is that not must be worked with liquids. The selective membranes allow gas separation plants modular expansion with relatively little Weight and small space requirement.

From US-A-5 116 650 (Bowser) is a gas permeable, main material known for gas filters and the like, known with a body made of porous PTFE as a carrier material a coating of an amorphous copolymer of 10-11 mol% Tetrafluoroethylene and additionally 90-60 mol% perfluoro-2,2-dimethyl-1,3-dioxole having. The coating is said to be the porous of the porous Do not clog PTFE, but only thinly over the pore structure pull so that the continuous porosity of the material is preserved.

EP-A-0 108 499 (Swick) also describes gas / gas separation membrane used to separate hydrogen sulfide known from a gas mixture, the membrane being a porous Carrier (made of PTFE) and has a thin coating layer, which for Hydrogen sulfide is permeable.

However, the use of selective membranes is that described above Kind of not always satisfactory because the selectivities are low are and the permeabilities for each to be separated Gas components are low, with the result that with high Pressing on the side of the active layer needs to be worked.  

The above-mentioned section of gas separation plants that working with non-selective membranes is based on the fact that certain membranes permeable to gases, but liquids are impermeable. One separates in so-called gas / liquid contactors microporous, hydrophobic, non-selective membrane that to Separating gas component containing gas phase from a liquid Absorbent, for example a water-miscible or aqueous, aminic absorbent (e.g. monoethanolamine, which leads to an An 30% is mixed with water). Non-selective ones are known Membranes made of polyethylene (PE), polypropylene (PP) and polytetrafluor ethylene (PTFE).

In WO 95/26225, various properties are described under different membrane materials. Also find yourself in this publication explanations of works which in turn in Ver bonded with the different membrane materials were. So z. B. reports that by comparison of absorber modules with hollow fibers made of PP, PE and PTFE was found that the membranes made of PP and PE with time in their absorption ability to abate. In addition, because of this he knowledge focused on PTFE membranes, although certain PTFE Show disadvantages.

As further stated in WO 95/26 225, it has been found in the investigation of absorber modules with PP and PE membranes that such membranes tend to leak. The permeation of liquid absorbent to the gas side supposedly makes the operating conditions unstable. In the publication, therefore, as a solution to the problem of leakage of liquid absorbent towards the gas side, it is proposed to use a liquid as the absorber liquid which cannot penetrate the membrane towards the gas side thereof. A special parameter of an absorber liquid that meets this requirement is its surface tension, which should be more than 60 × 10 ^-3 N / m at 20 ° C. at 20 ° C.

According to WO 95/26225, the focus is on ge wanted to avoid leakage of liquid absorbent Gas side towards the choice of absorption liquid.

Specifically, by setting a minimum surface tension Permeation of the absorption liquid can be prevented.

However, the inventors of the present invention are based on sub Searches come to the conclusion that the surfaces are too small voltage is not necessarily the cause of pore breakthroughs in the Membrane is; because pore openings due to insufficient surfaces voltage should be immediately after contacting the respective Fluid occur. However, the inventors have found that the Permeation of the liquid absorbent to the gas side in the known Membranes can only be detected after a few weeks. From this it can be concluded that the surface tension is certainly not alone decisive for the permeation of liquid through the membrane.

As further causes of liquid permeation to the gas side are still considered: the adhesion potential, which is hydro phobic surfaces is relatively strong, the adsorption by electro static interactions, evaporation and condensation binary mixtures with a hygroscopic component.

The object of the present invention is a method for absorbing a gaseous component from a gas phase indicate which stable operating conditions in long-term operation guaranteed. In addition, a method for desorbing one of a liquid absorbent absorbed gas component from the liquid absorbent can be specified. Finally, the invention aims a system for separating a gaseous component from a  Create gas phase. These three objects of the invention are achieved by one first, a second and a third aspect of the invention achieved.

According to a first aspect of the invention, a method is involved for separating one or more gaseous components from one Gas phase, in which the gas phase over a microporous carrier layer and a dense layer applied on the support layer in contact brought with a liquid absorbent, e.g. B. one with water miscible or aqueous, amine absorbent. The "membrane" is is designed such that the permeation of liquid absorbent on the gas side is permanently prevented.

While in the above-mentioned WO 95/26 225 the liquid absorbent is selected or adjusted in such a way that leakage to the gas side is prevented especially in the case of membranes which are not made of PTFE, the present invention takes a different approach. According to the invention, the membrane is designed in such a way that the permeation of liquid absorbent to the gas side is permanently prevented; this makes it possible to use virtually any absorption liquids, even those with surface tensions of less than z. B. 60 × 10 ^-3 N / m at 20 ° C.

In a particularly preferred embodiment, the membrane contains a microporous PTFE carrier layer and the relatively thin dense layer, but a high one for polar gases Permeability. This "dense layer", i.e. H. non-porous Layer, has a thickness of 0.1 µm. . . 10 µm, preferably from 1 Micrometer. A perfluorodioxole layer is the preferred layer used. This layer is in WO 90/15662 discussed above explained in detail. For more details on this material reference is made to this publication. The substance is e.g. B. from the DuPont sold under the trade name "Teflon AF".  

If the gas component to be separated is water vapor, the tight one is Layer an ionomer layer, preferably a perfluorinated ionomer layer, e.g. B. "Nafion" (trade name of DuPont).

With gas components to be separated, such as CO₂, SO₂, H₂S or NH₃ the absorbent is preferably an amine absorbent compatible with these Gases undergo a chemical reaction. When water is separated Vapor from a gas phase is used as the absorbent glycol, in particular Triethylene glycol used, which with the water molecules a physi Kalic bond enters.

As is clear from the prior art discussion above, such a membrane has already been used in the prior art, however as a so-called "selective membrane", which is used for certain gases is permeable, but not for other gases. The present However, the invention is based on a completely different mechanism of gas separation, namely on the use of a liquid absorbent, which one or more gas components due to a chemical Separates reaction from a gas mixture. These mechanisms of Gas / liquid contactors are fundamentally different from those so-called selective membranes in gas / gas separators, in which very high pressures are generated on the side of the active layer need to get only the desired polar gas through the layer forward.

The gas / liquid contactors, on the other hand, get the entire gas phase into the membrane and in contact with the absorbent, then only the component (s) to be absorbed reacts with the absorbent (react).

While due to the gas / gas separators with selective membrane the enormous pressures on the high pressure side of the mechanism of the gas separation seems plausible and understandable was the usability of one such a membrane with a relatively thick carrier layer and  thin active layer with gas / liquid membrane contactors expect; because those prevailing in this type of gas separator Gas pressures on the gas side of the membranes are significantly lower (about 2 to 10 kPa above atmospheric pressure) than the pressures on the High pressure side of gas / gas separators (5 to 10 MPa).

A particular advantage of using a Membrane that has a permeation of liquid, amine absorbent prevents the gas side, is the reversibility of the in the Ab chemical reaction taking place between the absorbent and the gas component. Because of this property, one can Desorbing method using similar equipment and ver Carry out driving steps, such as the procedure for disconnecting one Gas component from a gas phase.

According to a second aspect of the invention, a method is involved for desorbing one from a liquid, miscible with water or aqueous absorbent absorbed gas component from the liquid absorbent, in which the absorbent is a microporous Carrier layer and a dense layer applied thereon, both up approx. 150 ° C are temperature stable, is brought into contact with the Ab sorbent is supplied with thermal energy at least in the vicinity of the membrane is, and the desorbed gas component from that of the absorbent opposite side of the layer arrangement (membrane) is transported away.

The membrane is designed to allow the permeation of liquid Absorbing on the gas side permanently prevented.

The chemical reaction between the liquid absorbent (e.g. Mo noethanolamine) and the gas component to be separated (e.g. CO₂ Exhaust gas) on the absorber side can be reversed by supplying energy. At temperatures above the temperature at which the Connection between the absorbent and the separated gas again disintegrates (with amine / CO₂ compounds this temperature is 110-130 ° C)  can by means of this reverse reaction by supplying heat in a desorber membrane module the gas component (e.g. CO₂) be desorbed from the liquid absorbent. The desorbed gas will then passed on to further treatment, for example as process gas used and the like.

According to a third aspect of the invention, the invention provides Plant for the separation of one or more gaseous components from a gas phase, characterized by the following features:

• a) an absorber membrane module, in particular in accordance with the method according to claim 1, flows through the liquid absorbent on the one hand and the gas phase on the other hand a membrane, for which purpose the absorber membrane module
  • a1) a gas inlet;
  • a2) a gas outlet;
  • a3) an absorbent inlet;
  • a4) an absorbent outlet; and
  • a5) has a membrane structure which contains a microporous support layer and a dense layer applied thereon.

Through this membrane structure, the permeation of liquid Ab sorbent permanently prevented on the gas side.

Such an installation is made by a suitable connection of the inlets and Outlets formed in a circuit in which the system fol the following additional features:

• b) a liquid absorber flows through and contains a desorber membrane module, in particular in accordance with the method according to claim 2
  • b1) an absorbent inlet;
  • b2) an absorbent outlet;
  • b3) a gas outlet;
  • b4) means for supplying heat to the absorbent nearby
  • b5) a membrane structure which is formed in accordance with the membrane in the absorber membrane module.

With such a system you can practically identical training Membrane modules for both the absorber side and the desorber insert side. For example, one uses an arrangement Flat membranes, but an arrangement of membrane hollow fibers is preferred, on the inner liquid side there is a thin perfluoro Dioxole layer is located, the hollow fibers inserted in a housing are closed, which is traversed by gas, while the ends of the individual hollow fibers to an absorbent collection inlet or outlet are connected. The one containing the gas component to be separated Gas mixture is passed into the absorber module so that the gas mixture flows around the hollow fibers and the gas mixture penetrates into the membrane and the gas component to be absorbed from the liquid absorbent is recorded. The be with the gas component loaded absorbent is directed to the desorber module and through there headed the analog module module. The module is at for example by the inflow of steam on the gas side or with the help a special heater on z. B. 120 ° C (with amine / CO₂-Ver bonds) heated, the released on the liquid side CO₂ permeated through the membrane to the gas side. From the outside of the Hollow fibers can then the resulting gas z. B. sucked off by vacuum will. It can also with the help of a purge gas, e.g. B. ent ent be removed. If, as preferred, the heat supply by means of water steam occurs, the desorbed gas together with the steam away. Then from the desorber membrane module Gas component freed absorbent back to the absorber membrane module.  

The present invention focuses on the use of a special design of the membrane, so that the procurement alone the membrane permeability of the liquid absorbent to the gas side is prevented. Responsible for the failure to Liquid permeation to the gas side is primarily that of the relatively thin PTFE layer, very thin active layer from z. B. "Teflon-AF®" on the side of the liquid. This material forms a "dense layer", in contrast to the "microporous" Carrier layer. Surprisingly, it has been shown that this "dense Layer "the gas component to the liquid absorbent in sufficient lets the crowd through. The dense layer consists of an amorphous Polymer of perfluoro-2,2-dimethyl-1,3-dioxole (perfluorodioxole) ent speaking of the disclosure of WO 90/15662. This publication goes to an invention from 1989. The above explained beat according to WO 95/26 225, namely the setting of a min least surface tension of the liquid absorbent to avoid the Liquid permeation to the gas side is based on an invention 1994. The inventors of the latter proposal are open bar as well as the rest of the experts do not suspect that the 1989 membrane used for gas / gas separators for Gas / liquid membrane contactors could be suitable.

In the following, exemplary embodiments of the invention are described with reference to the Drawing explained in more detail. Show it:

Fig. 1 shows a plant for separating a gaseous component from a gas phase, as well as to regenerate the liquid absorbent used for the separation,

Fig. 2 is a schematic longitudinal sectional view of an absorber membrane module, as it can be used in the system according to Fig. 1, and

Fig. 3 is a schematic sectional view through a membrane used according to the Invention.

The system, generally designated 1 in FIG. 1, is used to purify exhaust gas from a power plant operated with fossil fuels. The exhaust gas contains, among other things, a share of e.g. B. about 6% CO₂. This exhaust gas is introduced via a gas inlet AG1 into an absorber membrane module A and leaves with only a portion of z. B. 1% CO₂ module A through a gas outlet AG2.

Most of the absorber membrane module A (5% CO₂) of the exhaust gas with the help of the described below, as Membrane contactor trained absorber membrane module A from the Exhaust gas removed. For this, a mixture of water with 30% mono ethanolamine (MEA) via an absorbent inlet AF1 into the absorber initiated membrane module A, absorbs CO₂ by chemical reaction and is connected via a connecting line V1 as a MEA loaded with CO₂ from an absorbent outlet AF2 of the absorber membrane module A one Desorber membrane module D fed.

The desorber membrane module D contains the absorbent inlet DF1 and an absorbent outlet DF2. The desorber membrane module D is about an energy supply device DQ thermal energy Q is supplied. In the front lying example, the thermal energy Q is increased by hot steam guided; alternatively, an electrical or other powered Heating device may be provided.

The reverse chemical reaction takes place in the desorber membrane module D as in the absorber membrane module A because the chemical reaction is reversed by the supply of thermal energy Q. This chemical reaction separates the CO₂ from the MEA loaded with the CO₂. For this purpose, the desorber membrane module D can be constructed identically to the absorber membrane module A, which will be explained in more detail below. The MEA largely freed from the CO₂ comes from the Aborbensauslaß DF2 via the connecting line V2 and the pump P to the absorbent inlet AF1 of the absorber membrane module 1 , whereby the circuit of the absorber liquid is closed.

That from the gas side of the membrane in the desorber membrane module D withdrawn CO₂ can be processed further.

FIG. 2 shows, by way of example only, a possible embodiment for the absorber membrane module A and / or the desorber membrane module D.

The module here should be the absorber membrane module A. It contains the gas inlet AG1 and the gas outlet AG2, which are formed at diametrically opposite ends of the jacket of a cylindrical housing 20 . The end faces of the cylindrical housing 20 are closed by a plate 22 or 24 formed from potting compound. The two plates 22 and 24 are penetrated by the ends of hollow fiber membranes 25 which are open at the end and which penetrate the cylindrical housing 20 essentially in the axial direction.

In Fig. 2 only a few hollow fiber membranes 25 are shown representative of a variety of such hollow fibers. The formation of hollow fiber membranes has already been disclosed by the applicant in an earlier patent application (DE-A-44 12 756; Witzko).

At the two end faces of the cylindrical housing 20 and the closure plates 22 and 24 located therein, covers 26 and 27 connect, which form a cavity 28 and 29 with the respective end face. The covers 26 and 27 open into hose or pipe couplable connecting stub for the absorbent inlet AF1 and the absorbent outlet AF2.

The mixture of MEA / water is introduced via the absorbent inlet AF1 and the adjoining chamber 28 into the front ends of the hollow fiber membranes 25 . The liquid absorbent flows through the bundle of hollow fiber membranes 25 and takes up the majority of the CO₂ from the 6% CO₂-containing exhaust gas. The exhaust gas is introduced via the gas inlet AG1 into the interior of the cylindrical housing 20 and flows in counterflow, that is, counter to the direction of flow of the liquid absorbent, to the exhaust gas outlet AG2, the exhaust gas with the CO₂ contained therein covering the outer surface of the individual hollow fibers 25 . The direction of flow of the liquid absorbent in the hollow fibers is indicated by solid arrows, the flow path of the exhaust gas is indicated by dashed arrows. The left in Fig. 2 ends of the individual hollow fibers 25 open into the chamber 29 , and from this chamber 29 , the mixture loaded with CO₂ of MEA / water flows into the absorbent outlet AF2.

The exhaust gas flowing out of the gas outlet AG2 contains only 1% CO₂. The liquid absorbent flowing out via the outlet AF2 reaches the desorber membrane module via the connecting line V1 shown in FIG. 1.

The desorber membrane module is constructed similarly to the module shown schematically in FIG. 2, but the gas inlet AG1 can be open or closed; because at the gas outlet, the CO₂ gas is sucked off, which has been desorbed by chemical reaction at elevated temperature from the CO₂-laden MEA / water mixture. For this purpose, the module shown schematically in Fig. 2 is washed with water vapor, so that a temperature of more than 110 ° C prevails within the housing 20 . At this temperature, the chemical reaction taking place in the absorber membrane module A is reversed for the purpose of absorption of a gas component (CO₂), so there is a desorption of CO₂ in the desorber membrane module D.

Fig. 3 shows a section through a membrane. The membrane shown in FIG. 3 represents the hollow fibers 25 contained in the module according to FIG. 2.

The inside of the individual hollow fibers by flowing liquid (MEA, mixed with water) is indicated at 10 at the bottom in FIG. 3. The membrane 2 , which is composed of two layers, contains a carrier layer 4 made of microporous PTFE (ePTFE), which has a thickness of approximately 200 micrometers. On this microporous support layer there is a "dense layer" of perfluorodioxole, and beyond this layer 6 flows the exhaust gas 8 to be freed from CO₂. For details of the membrane 2 shown in FIG. 3 with its two layers 4 and 6 , reference is made to the above-mentioned WO 90/15662.

While exemplary embodiments of the invention have been explained above, the person skilled in the art understands that the invention is not restricted to these specific details. The invention can be removed not only for separating CO₂ from exhaust gases, natural gas and the like, but it can also be used to separate other gas components with the help of gas / liquid membrane contactors. Of course, the module shown schematically in FIG. 2 is only an example of a number of possible module designs.

In the embodiment described above, CO₂ absorbed from exhaust gases, for example. The invention is of course not be on this gas component as a gas component to be separated limits, it can also, for example, hydrogen sulfide (H₂S) be desorbed.

The MEA absorbent specifically specified above is also not as to understand restrictively. Basically come as absorbers materials the amines known per se, in particular the for absorbing H₂S and CO₂ from natural gases and exhaust gases used alkanolamines (diethanolamine, triethanolamine, diisopro panolamin etc.).  

In the above embodiment, the membrane is designed as a hollow fiber pack ( Fig. 2). The design of the absorber membrane module or the desorber membrane module is not limited to such membrane shapes. B. also flat membranes.

example 1

In order to test the method according to the invention, a membrane test rig was used built, in which a membrane module on the one hand Membrane on a MEA as an absorption fluid carrying liquid flow and on the other hand is coupled to a gas circuit. The liquid circuit barrel contains a pump so that the absorption fluid is constantly on the Membrane surface of the test module strokes.

A Sepa CF test cell from Fa. Osmotics with an effective membrane area of 0.013 m² is used. The liquid flow on the absorption fluid side was 2 l / min. With the help of the pump, in the liquid circuit, consisting of a 30% MEA water solution, circulated. The The temperature of the solution was adjusted to 30-33 ° C.

The gas mixture was a CO₂-air mixture with a CO₂ content between 5.5 and 6.5%. The gas side flow rate the membrane was varied between 1 l / min and 6 l / min, the Gas temperature was set to 30 to 33 ° C. The relative humidity the gas fluctuates between 10% and 15%.

To the CO₂ content of the gas mixture after flowing through To measure the test cell was downstream of the test cell a CO₂ analyzer with which the CO₂ content according to the infrared principle was measured.  

After starting the test, it takes 10 minutes to sets a constant absorption of CO₂.

The membrane was designed as a composite membrane, consisting of a carrier layer made of microporous ePTFE with a 1 µm thick Teflon AF layer applied thereon. Membrane area: 1.3 × 10 ^-3 m². Liquid throughput: 3.3 × 10 ^-5 m³ / s; Liquid temperature: 31.5 ° C; and liquid pressure: 8 kPa.

The gas volume flow was 3.3 × 10 ^-5 m³ / s at a gas temperature of 32.5 ° C after reaching the constant gas absorption.

In order to obtain a measurement value suitable for a comparison, the mass transfer coefficient K calculates:

K = Q / A * ln (Xein / Xaus)

with Q = gas volume flow; A = membrane area; Xein = input CO₂ concentration and Xout = initial CO₂ concentration.

Result: K = 1.03 × 10 ^-3 m / s.

The trial was carried out as a long-term trial, which lasted 10 days lasted, during this 10 day period the membrane remained on the gas side at a pressure of 20 kPa come dry; mass transfer remained constant.

Example 2 (comparative example)

The same experiment as in Example 1 was carried out, with only a different material was used for the membrane, namely a homogeneous microporous membrane made of ePTFE with a Pore size of 0.2 µm and a thickness of 35 µm.  

A K value of K = 3.60 × 10 ^-3 m / s was calculated.

However, after one to two hours of contact with the 30% MEA water solution on the gas side liquid MEA in the form little droplet. In the further course of the experiment, these formed Liquid droplets form a coherent liquid film that obstructed the passage of gas and eventually to a drastic Mass transfer deterioration resulted.

A further test similar to Example 1 was carried out led, but using a microporous ePTFE membrane with a thick layer of FEP formed thereon with a thickness of 5 µm. The calculated K value for this composite membrane was very low and was in the range of measurement inaccuracy, so that closer Information is not useful.

The above description of specific embodiments and examples play the invention relates primarily to the separation of CO₂ a gas phase.

However, as already mentioned at the beginning of the description, is suitable the inventive method as well as the inventive Plant also for dehumidifying gases by removing from a gas phase Water vapor is separated. For this purpose, a membrane Carrier layer with a dense layer of a applied thereon Ionomer, preferably a perfluorinated ionomer used. A such a "dense layer" z. B. from DuPont under the Commercial name "Nafion" distributed. This dense layer leaves the a polar gas forming water molecules, which then with the form a physical bond with the liquid absorbent. The liquid In this case, absorbent is preferably an aqueous glycol solution triethylene glycol is used.

Claims (22)

1. A process for separating one or more gaseous com ponents from a gas phase, wherein the gas phase through a microporous support layer (4) and a coating applied to the carrier layer (4) impermeable layer (6) in contact with a liquid absorbent (10) is brought. 2. A method for desorbing a gas component absorbed by a liquid absorbent from the absorbent, in which a microporous carrier layer ( 4 ) and a dense layer ( 6 ) applied to the carrier layer ( 4 ) are brought into contact with the absorbent, at least the absorbent heat energy (Q) is supplied in the vicinity of the layer arrangement, and the desorbed gas component is removed from the side of the layer arrangement facing away from the absorbent. 3. The method according to claim 1 or 2, characterized in that the membrane formed by the support layer and the dense layer has a fluoropolymer layer as the dense layer. 4. The method according to claim 3, characterized in that the A microporous PTFE membrane as a support layer for the membrane has a dense layer. 5. The method according to any one of claims 1 to 4, characterized indicates that the gases to be separated are polar gases. 6. The method according to any one of claims 1 to 5, characterized in that the dense layer ( 6 ) has a thickness of 0.1 µm to 10 µm, preferably of 1 µm. 7. The method according to any one of claims 1 to 6, characterized in that the dense layer ( 6 ) is a perfluorodioxole layer. 8. The method according to any one of claims 1 to 7, characterized records that the liquid absorbent is an aminic absorbent. 9. The method according to any one of claims 1 to 8, characterized records that the gas component to be absorbed CO₂, SO₂, H₂S or Is NH₃. 10. The method according to any one of claims 1 to 9, characterized records that the absorbent is a chemical reaction with the ab separating gas component. 11. The method according to any one of claims 1 to 7, characterized records that the absorbent, preferably an aqueous solution of glycol has triethylene glycol. 12. The method according to any one of claims 1 to 7 and 11, characterized characterized in that the gas component to be separated is water vapor is. 13. The method according to any one of claims 1 to 7, 11 and 12, characterized characterized in that the dense layer is a, especially perfluorinated, Is ionomer layer. 14. The method according to claim 2, characterized in that by the supply of thermal energy at least in the area of the dense layer a temperature of more than 110 ° C is set. 15. The method according to any one of claims 1 to 8, characterized records that the absorbent is an aqueous solution of organic Amines, e.g. B. monoethanolamine or methyldiethanolamine.   16. The method according to any one of claims 1 to 15, characterized in that the layer arrangement is designed as a hollow fiber ( 25 ) through which the absorbent flows. 17. The method according to any one of claims 1 to 16, characterized records that the carrier layer and the dense layer up to about 150 ° C. is temperature resistant. 18. The method according to any one of claims 1 to 17, characterized in that the absorber liquid has a surface tension of less than about 60 × 10 ^-3 N / m. 19. Plant for separating one or more gaseous components from a gas phase, characterized by the following features:

• a) an absorber membrane module (A) is flowed through, in particular in accordance with the method according to claim 1, of a liquid, water-miscible or aqueous absorbent on the one hand and the gas phase on the other hand of a membrane ( 2 ; 25 ), for which purpose the absorber membrane module (A)
  • a1) a gas inlet (AG1);
  • a2) a gas outlet (AG2);
  • a3) an absorbent inlet (AF1);
  • a4) an absorbent outlet (AF2); and
  • a5) a membrane structure ( 25 )

The membrane of the membrane structure is a micro-porous carrier layer with a dense layer ( 6 ) applied thereon. 20. Plant according to claim 19, characterized by the features:

• b) a liquid, water-miscible or aqueous absorbent flows through and contains a desorber membrane module (D), in particular in accordance with the method of claim 2
  • b1) an absorbent inlet (DF1);
  • b2) an absorbent outlet (DF2);
  • b3) a gas outlet (DG);
  • b4) a device (DQ) for supplying heat to the absorbent at least nearby
  • b5) a membrane structure ( 25 ) which is designed like the membrane structure of the absorber membrane module.

21. Plant according to claim 20, in which by connecting the Absorbent inlets and outlets of the absorber membrane module and the desorber membrane module (A, D) forms a circuit.