Method and separator for separating a target gas from a substance mixture

Abstract

The invention relates to a method (100) for separating a target gas from a substance mixture. The method (100) comprises: - introducing (101) the substance mixture into a housing (201) in which a plurality of electrodes (203) are arranged; - applying (103) a voltage to the electrodes (203) in order to enrich the target gas at the electrodes (203); - flooding (105) the housing (201) with ionic liquid; - reversing (107) the voltage applied to the electrodes (203) in order to expel the target gas from the electrodes (203); - discharging (109) the target gas from the housing (201). The invention further relates to a separator (200) for separating a target gas from a substance mixture and to an energy converter (300) for converting energy.

Description

[0001] R.414315

[0002] - 1 -

[0003] Description

[0004] title

[0005] Methods and separators for separating a target gas from a mixture of substances

[0006] The presented invention relates to a method for separating a target gas from a mixture of substances, a separator for separating a target gas from a mixture of substances and an energy converter for converting energy according to the attached claims.

[0007] State of the art

[0008] Methods and systems for separating gases from mixtures of substances, such as carbon dioxide from the air or exhaust gas from an internal combustion engine, are known. Typically, the mixture is passed over electrodes to which a voltage is then applied.

[0009] A separator located between the electrodes electrically isolates them. Ions from an ionic liquid, however, can pass through the separator, thus enabling charge equalization. To bind the deposited gas, the flow of electrons and ions must be driven by applying a voltage. The gas is released by reversing the polarity of the voltage.

[0010] To separate the gas, a vacuum is applied to a housing containing the electrodes and maintained for a specified time. R.414315

[0011] - 2 -

[0012] Disclosure of the invention

[0013] Within the scope of the presented invention, a method for separating a target gas from a mixture of substances, a separator for separating a target gas from a mixture of substances, and an energy converter for converting energy are presented. Further features and details of the invention will become apparent from the respective dependent claims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the separator and the energy converter according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal references.

[0014] The presented invention serves in particular to enable the rapid separation of a target gas from a mixture of substances. In particular, the presented invention serves to provide an improved method for separating carbon dioxide from a mixture of substances.

[0015] Thus, according to a first aspect of the presented invention, a method for separating a target gas from a mixture of substances is presented.

[0016] The presented method comprises introducing the mixture into a housing in which a plurality of electrodes are arranged, applying a voltage to the electrodes to enrich the target gas at the electrodes, flooding the housing with ionic liquid, reversing the voltage applied to the electrodes to drive the target gas out of the electrodes, and removing the target gas from the housing.

[0017] The presented invention is based on an ionic liquid with which a housing containing electrodes for separating a target gas is flooded. Flooding the entire housing with the ionic liquid expels or minimizes residual gas from the housing, thus minimizing any harmful effects of the residual gas on the separation process. R.414315

[0018] - 3 -

[0019] Accordingly, the electrodes in the housing are completely surrounded or soaked with ionic liquid, so that they can operate in an anaerobic atmosphere and expel correspondingly large quantities of target gas per unit of time.

[0020] Optionally, using the presented method, it is possible to forego applying a negative pressure or a vacuum to the housing, since the influence of residual gas remaining in the housing when the target gas is expelled from the electrodes is negligible.

[0021] It may be intended that the ionic liquid is saturated with the target gas.

[0022] By means of an ionic liquid saturated with the target gas, such as carbon dioxide, the target gas driven out of the electrodes is directly converted into a gas phase and deposited on a surface of the ionic liquid.

[0023] It may be stipulated that the target gas is carbon dioxide.

[0024] The presented method is particularly suitable for separating carbon dioxide from a mixture of substances, such as air or exhaust gas from a combustion unit of a chemical energy converter, in particular an internal combustion engine or a heating system.

[0025] It may also be provided that after the target gas has been removed from the housing, the ionic liquid is expelled from the housing.

[0026] By expelling the ionic liquid, e.g., by applying a vacuum to the housing and / or by opening a drain valve, the housing is prepared to receive a further quantity of fresh mixture. Accordingly, after the ionic liquid has been expelled from the housing, the described process can be repeated to successively separate a target gas from a large quantity of mixture. R.414315

[0027] - 4 -

[0028] It may also be provided that the ionic liquid is driven out of the casing by a mass flow of fresh mixture.

[0029] In the event that a flowing mass stream of a mixture, such as exhaust gas from an internal combustion engine, is provided, the potential energy supplied by the mass stream can be used to expel the ionic liquid from the housing. For this purpose, the mass stream can, for example, be guided through an inlet into the housing that is opposite an outlet for the removal of the ionic liquid, so that the mass stream forces the ionic liquid into the outlet.

[0030] It may also be provided that a negative pressure is created in the housing after it has been flooded with the ionic liquid.

[0031] A negative pressure, particularly a vacuum in the flooded housing, causes gases to be expelled from the ionic liquid. This means that if the negative pressure is applied before the voltage is applied to the electrodes, any residual gas present in the ionic liquid is expelled, and if the negative pressure is applied after the voltage is applied, the target gas is expelled from the ionic liquid. To achieve this, valves can be closed to block the inlet and / or outlet of the housing when the negative pressure is applied.

[0032] Due to the ionic liquid, the application of the vacuum can be particularly fast, i.e., for a short period of, for example, a few seconds, especially between 2 seconds and 50 seconds.

[0033] It may also be provided that the mixture is an exhaust gas emitted by a combustion unit.

[0034] The presented method has proven particularly suitable in tests for separating carbon dioxide from the exhaust gas of a combustion unit, such as a heating system or an internal combustion engine used to burn carbon-containing fuels. R.414315

[0035] - 5 -

[0036] It may also be provided that, when flooding the housing with the ionic liquid, the ionic liquid is at least partially passed through the housing repeatedly.

[0037] By repeatedly passing the ionic liquid through the housing, the housing is purged with the ionic liquid, so that essentially all residual gas is expelled from the housing. A recirculation circuit for the ionic liquid between a reservoir supplying the ionic liquid and the housing can be used for this purpose. The recirculation circuit can, for example, include a recirculation pump.

[0038] According to a second aspect, the presented invention relates to a separator for separating a target gas from a mixture of substances.

[0039] The presented separator comprises a housing, a plurality of electrodes arranged in the housing, a reservoir in which ionic liquid is stored, a piping system that fluidly connects the reservoir to the housing, a pump configured to pump ionic liquid from the reservoir via the piping system into the housing, and a discharge system configured to remove target gas accumulating in the housing.

[0040] The presented separator is particularly suitable for carrying out the presented procedure.

[0041] The piping system may include at least one switchable valve configured to release the fluid-conducting connection between the reservoir and the casing in a release position and to close it in a blocking position, wherein the draining system includes at least one switchable valve configured to release a fluid flow from the casing in a release position and to block it in a blocking position. R.414315

[0042] - 6 -

[0043] A switchable valve for blocking or releasing a drainage system for removing fluid from the housing allows control of a reaction taking place in the housing, for example by moving the valve to its release position to drain accumulated target gas in the housing or to its blocking position to allow complete flooding of the housing with ionic liquid.

[0044] It may also be provided that the drainage system includes a vacuum pump configured to apply a vacuum to the housing.

[0045] By applying a vacuum inside the housing, residual gas can be expelled from the housing, especially from the housing containing ionic liquid.

[0046] It may also be provided that the separator includes a computing unit configured to control the separator and to carry out a possible implementation of the presented procedure.

[0047] In the context of the presented invention, a computing unit is understood to be a computer, in particular a cloud computer, a processor, a control unit or any other programmable circuit.

[0048] According to a third aspect, the presented invention relates to an energy converter for converting energy.

[0049] The presented energy converter comprises a combustion unit and a possible embodiment of the presented separator, wherein an exhaust gas line of the combustion unit is fluidly coupled to the separator, and wherein the separator is configured to separate carbon dioxide from an exhaust gas provided by the combustion unit.

[0050] Due to the separator presented, the combustion unit shown, which could be, for example, an internal combustion engine or a heating system, is particularly climate-friendly. R.414315

[0051] - 7 -

[0052] Advantages described in detail for the method of separating a target gas from a mixture of substances according to the first aspect of the invention apply equally to the separator for separating a target gas from a mixture of substances according to the second aspect of the invention and to the energy converter for converting energy according to the third aspect of the invention, and vice versa.

[0053] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination.

[0054] They each show schematically:

[0055] Figure 1 shows a possible embodiment of the presented method,

[0056] Figure 2 shows a possible embodiment of the presented energy converter with a possible embodiment of the presented separator in a first operating position,

[0057] Figure 3 shows the separator according to Figure 2 in a second operating position,

[0058] Figure 4 shows the separator according to Figure 2 in a third operating position, and

[0059] Figure 5 shows the separator according to Figure 2 in a fourth operating position.

[0060] Figure 1 shows a method 100 for separating a target gas from a mixture of substances.

[0061] The method 100 comprises an introduction step 101 in which the mixture is introduced into a housing in which a plurality of electrodes are arranged, an application step 103 in which a voltage is applied to the electrodes- R.414315

[0062] - 8 - is placed to enrich the target gas at the electrodes, a flooding step 105 in which the housing is flooded with ionic liquid, a reversal step 107 in which the voltage applied to the electrodes is reversed to drive the target gas out of the electrodes, and a discharge step 109 in which the target gas is discharged from the housing.

[0063] In Fig. 2 an energy converter 300 for converting energy with a separator 200 for separating a target gas from a mixture of substances, namely an exhaust gas of a combustion unit 301 of the energy converter, as indicated by arrow 303, is shown.

[0064] The separator 200 comprises a housing 201, a plurality of electrodes 203 arranged in the housing 201, a reservoir 205 in which ionic liquid is stored, a piping system 207 which fluidly connects the reservoir 205 to the housing 201, a pump 209 which is configured to pump ionic liquid from the reservoir 205 via the piping system 207 into the housing 201, and a discharge system 211 which is configured to discharge target gas accumulating in the housing 201 from the housing 201.

[0065] A first switching valve 213 is arranged in the piping system 207 to block or release the flow of ionic liquid through the piping system 207.

[0066] Furthermore, the piping system 207 includes a check valve 217, which prevents ionic liquid flowing from the housing 201 into the storage tank 205 from flowing back into the storage tank.

[0067] A second switching valve 215 is arranged in the drainage system 211 to block or release the flow of fluid through the drainage system 211.

[0068] A feed path 219 directs exhaust gas from the combustion unit 301 into the housing 201. For this purpose, the feed path 219 includes a feed valve 221, which is open (R.414315).

[0069] - 9 - can be opened to release a mass flow of exhaust gas into housing 201, or closed to block a mass flow of exhaust gas into housing 201.

[0070] In the operating state shown in Fig. 2, exhaust gas flows through the feed path 219 into the housing 201 and accumulates there.

[0071] By applying a voltage to the electrodes 203, carbon dioxide contained in the exhaust gas is deposited on the electrodes 203. The first switching valve 213 and the second switching valve 215 are in their closed position, respectively.

[0072] In the operating state shown in Fig. 3, the feed valve 221 is closed, and ionic liquid saturated with carbon dioxide is pumped into the housing 201 by the pump 209. Accordingly, the first switching valve 213 is in its enabling position, i.e., open.

[0073] Residual gas displaced from the housing 201 can be blown out via an optional vent 223.

[0074] In the operating state shown in Fig. 4, the voltage applied to the electrodes 203 is reversed relative to the operating state shown in Figs. 2 and 3, so that carbon dioxide deposited on the electrodes 203 is carried out of the electrodes 203 and accumulates in the housing 201 at the top.

[0075] By switching the second switching valve 215 into its release position, the enriched carbon dioxide is discharged via the discharge system 211 into, for example, a storage tank.

[0076] In the operating state shown in Fig. 5, the feed valve 221 is open again, so that exhaust gas flowing into the housing 201 forces the ionic liquid located in the housing 201 into the storage tank 205, and the operating state according to Fig. 2 is established. R.414315

[0077] - 10 -

[0078] Optionally, to transfer the ionic liquid from the housing 201 to the storage tank 205, as indicated by arrow 225, a negative pressure can be created in the housing 201 by the pump 209.

Claims

R.414315 - 11 - Claims 1. Method (100) for separating a target gas from a mixture of substances, wherein the method (100) comprises: Introducing (101) the mixture into a housing (201) in which a plurality of electrodes (203) are arranged, Applying (103) a voltage to the electrodes (203) to enrich the target gas at the electrodes (203), Flooding (105) the housing (201) with ionic liquid, Reversing (107) the voltage applied to the electrodes (203) to drive the target gas out of the electrodes (203) and removing (109) the target gas from the housing (201).

2. Method (100) according to claim 1 , characterized in that the ionic liquid is saturated with the target gas.

3. Method (100) according to claim 1 or 2, characterized in that the target gas is carbon dioxide.

4. Method (100) according to one of the preceding claims, characterized in that after the target gas has been removed from the housing (201) the ionic liquid is expelled from the housing (201).

5. Method (100) according to claim 4, characterized in that the ionic liquid is driven out of the housing (201) by a mass flow of fresh mixture. R.414315 - 12 - 6. Method (100) according to one of the preceding claims, characterized in that after flooding (105) the housing (201) with the ionic liquid, a vacuum is created in the housing (201).

7. Method (100) according to one of the preceding claims, characterized in that the mixture of substances is an exhaust gas emitted by a combustion unit (301).

8. Method (100) according to one of the preceding claims, characterized in that when flooding (105) the housing (201) with the ionic liquid, the ionic liquid is at least partially repeatedly passed through the housing (201).

9. Separator (200) for separating a target gas from a mixture of substances, the separator (200) comprising: a housing (201), a plurality of electrodes (203) arranged in the housing (201), a reservoir (205) in which ionic liquid is stored, a piping system (207) that fluidly connects the reservoir (205) to the housing (201), a pump (209) configured to pump ionic liquid from the reservoir (205) via the piping system (207) into the housing (201), and - a drainage system (211) configured to remove target gas accumulating in the housing (201) from the housing (201). R.414315 - 13 - 10. Separator (200) according to claim 9, characterized in that the piping system (207) comprises at least one switchable valve (213) configured to release the fluid-conducting connection between the storage unit (205) and the housing (201) in a release position and to block it in a blocking position, wherein the discharge system (211) comprises at least one switchable valve (215) configured to release a fluid flow from the housing (201) in a release position and to block it in a blocking position.

11. Separator (200) according to claim 9 or 10, characterized in that the drainage system (211) comprises a vacuum pump configured to apply a vacuum to the housing (201).

12. Separator (200) according to one of claims 9 to 11, characterized in that the separator (200) comprises a computing unit configured to control the separator (200) and to perform a method (100) according to one of claims 1 to 8.

13. Energy converter (300) for converting energy, wherein the energy converter (300) comprises: a combustion unit (301) and a separator (200) according to any one of claims 9 to 12, wherein an exhaust gas line of the combustion unit (301) is fluidly coupled to the separator (200), and wherein the separator (200) is configured to separate carbon dioxide from an exhaust gas provided by the combustion unit (301).

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