METHOD FOR SEPARATING WATER FROM A GASEOUS WORKING MEDIUM, AND WATER SEPARATOR FOR A WORKING MEDIUM

Abstract

The invention relates to a method for separating water from a gaseous working medium (2), at least the following steps being carried out: providing an ionic hygroscopic liquid (4) in a reaction chamber (3); supplying the water-containing working medium (2) and conducting the working medium (2) through the ionic liquid (4), wherein water bonds with the ionic liquid (4) and is thereby separated from the working medium; and discharging the dried working medium (7). The invention further relates to a corresponding water separator (1) and to a water separator system (15).

Claims

1. A method of separating water out of a gaseous working medium, characterized in that at least the following steps are conducted: a) holding a hygroscopic ionic liquid in a reaction chamber; b) feeding the water-containing working medium into the reaction chamber and passing the working medium through the ionic liquid, wherein water is bound by the ionic liquid and hence separated out of the working medium; c) removing the dried working medium.

2. The method as claimed in claim 1, characterized in that the method is executed as a continuous method, wherein a working medium inlet for introducing the water-containing working medium into the reaction chamber and a clean medium outlet for discharging the dried working medium from the reaction chamber are provided in the reaction chamber, wherein the working medium to be dried is conducted upward through the ionic liquid counter to the field of gravity in the reaction chamber.

3. The method as claimed in claim 1, characterized in that the ionic liquid is reprocessed by heating the reaction chamber and removing the water separated out in vaporous form via a water outlet, wherein the ionic liquid is heated until the water content has been reduced to a predefined value, wherein the ionic liquid is heated for this purpose over an empirically determined heating time or the water content is determined by means of at least one of the following measures: determining the fill level of the ionic liquid; determining the mass of the ionic liquid; determining the mass of water separated out; and determining the electrical conductivity value of the ionic liquid.

4. The method as claimed in claim 1, characterized in that the ionic liquid is exchanged for reprocessing, wherein water-laden ionic liquid is especially drawn off from the reaction chamber and reprocessed ionic liquid is fed into the reaction chamber, and wherein the ionic liquid is exchanged continuously, wherein particles collected in the separation method are more filtered out at the same time.

5. The method as claimed in claim 3, characterized in that the distilled water obtained in the reprocessing is collected, wherein the ionic liquid is freed of particles beforehand by means of at least one filter.

6. The method as claimed in claim 1, characterized in that any dead space in the reaction chamber is reduced down to a desired level by means of raising the liquid level of the ionic liquid, down to a predefined safety margin from the clean medium outlet and/or the water outlet.

7. The method as claimed in claim 1, characterized in that the dried working medium to be removed is conducted through at least one coalescence filter in order to execute fine separation of water fractions before it is removed as clean medium and provided to a downstream process.

8. The method as claimed in claim 1, characterized in that, in step b), the separation of water out of the working medium in the reaction chamber is conducted at pressures in the reaction chamber in the range from 1 bar to 551 bar and/or at temperatures in the reaction chamber in the range from +60 C. to +250 C.

9. A water separator for a gaseous working medium to be dried, characterized in that the water separator comprises at least the following components: a liquid-tight reaction chamber to accommodate a hygroscopic ionic liquid, wherein the reaction chamber is filled with the hygroscopic ionic liquid, and wherein the reaction chamber is designed to bear an elevated pressure relative to the ambient atmosphere of the reaction chamber; a closable working medium inlet for introducing the gaseous and water-containing working medium to be dried into the reaction chamber, wherein the working medium inlet is arranged beneath the reaction chamber; and a closable clean medium outlet for removing the dried working medium from the reaction chamber, wherein the clean medium outlet is arranged above the reaction chamber.

10. The water separator as claimed in claim 9, characterized in that at least one preferably closable water outlet is additionally arranged above the reaction chamber, wherein evaporating water can be removed from the reaction chamber via the water outlet, in the course of reprocessing of the ionic liquid in the reaction chamber, and wherein the reaction chamber has at least one heating element for boiling off the water.

11. The water separator as claimed in claim 9, characterized in that at least one exchange outlet is additionally provided, beneath the reaction chamber, for supply of ionic liquid into the reaction chamber and for removal of ionic liquid from the reaction chamber.

12. The water separator as claimed in claim 9, characterized in that at least one inlet and at least one separate outlet are provided in the reaction chamber for the ionic liquid, such that the ionic liquid in the reaction chamber is continuously exchangeable.

13. The water separator as claimed in claim 9, characterized in that the clean medium outlet is put into flow connection with a coalescence filter set up for fine separation of water fractions from the dried working medium.

14. A water separator system for drying a working medium, characterized in that the water separator system has at least one water separator comprising a liquid-tight reaction chamber to accommodate a hygroscopic ionic liquid, wherein the reaction chamber is filled with the hygroscopic ionic liquid, and wherein the reaction chamber is designed to bear an elevated pressure relative to the ambient atmosphere of the reaction chamber; a closable working medium inlet for introducing the gaseous and water-containing working medium to be dried into the reaction chamber, wherein the working medium inlet is arranged beneath the reaction chamber; and a closable clean medium outlet for removing the dried working medium from the reaction chamber, wherein the clean medium outlet is arranged above the reaction chamber and at least one reprocessing apparatus for reprocessing the ionic liquid for the reaction chamber, wherein the reprocessing apparatus has at least one particulate filter for filtering out particulate impurities, and has at least one heating element for evaporating water that has separated out and at least one water outlet for removing evaporated water.

Description

[0055] The invention described above is elucidated in detail hereinafter against the technical background in question with reference to the accompanying drawings, which show preferred embodiments. The figures show.

[0056] FIG. 1: a water separator with a heating element; and

[0057] FIG. 2: a water separator system with a separate reprocessing apparatus.

[0058] FIG. 1 shows a water separator 1 in which a reaction chamber 3 filled with an ionic liquid 4 up to a liquid level 18 is provided. A heating element 10 which projects into the reaction chamber 3 can be used to heat the ionic liquid 4. At the lower end of the reaction chamber 3, a working medium inlet 5 is provided, via which (water-containing) gaseous working medium 2 to be dried, preferably natural gas or hydrogen, can be introduced into the reaction chamber 3.

[0059] Additionally provided is a clean medium outlet 6 at the top end of the reaction chamber 3, which in this example is arranged in a lid 29 (see below) of the reaction chamber 3. A dried working medium 7 can be removed via the clean medium outlet 6.

[0060] The reaction chamber 3 in operation preferably extends along a vertical longitudinal axis or cylinder axis, with the working medium inlet 5 and the clean medium outlet 6 opposite one another along the longitudinal axis. The reaction chamber 3 may have a cylindrical chamber wall 8 that extends along the longitudinal axis and may be closed at the bottom by a base joined to the wall (apart from any inlets and outlets). At the upper end, the reaction chamber 3 is preferably closed by the lid or cylinder head 29, which can be screw-connected to the wall 8 via screws, of which only the screwholes 23 are shown here in schematic form.

[0061] Additionally provided above the reaction chamber 3 is a water outlet 6 via which water vapor can be removed in the course of reprocessing of the ionic liquid 4, for example by means of heating of the ionic liquid 4 by means of the heating element 10. The clean medium outlet 6 and the water outlet 9 (see below) are preferably formed in the lid 29.

[0062] In addition, an exchange outlet 11 is arranged beneath the reaction chamber 3, via which the ionic liquid 4 can be supplied to and removed from the reaction chamber 3. In this example, the clean medium outlet 6 can be closed by means of the clean medium shutoff valve 21, for example when the ionic liquid 4 is being reprocessed (by means of heating). In addition, the water outlet 9 can also be closed by means of a water shutoff valve 22, for example during the separation phase when the water-containing working medium 2 is being dried. In addition, in this preferred example, a coalescence filter 14 is flow-connected to the clean medium outlet 6 downstream of the reaction chamber 3, and is set up and provided for fine separation of the residual water content in the dried working medium 7. Thereafter, a clean medium 20 can be fed to a downstream process or to a storage means. The dead volume of the reaction chamber 3 is very small here and is especially limited merely to a safety margin 19 between the liquid level 18 and the lid 29. Thus, the dead volume in the reaction chamber 3 is much smaller than is the case, for example, with beds. The water separator 1 shown here is particularly compact and allows continuous performance of the separation of water from the gaseous working medium.

[0063] FIG. 2 provides a water separator system 15 with a water separator 1 and a separate reprocessing apparatus 16, wherein the water separator 1 is of similar construction to that shown in FIG. 1 and, here too, the chamber wall 8 is preferably designed for elevated pressure relative to the surrounding atmosphere. In this case, by contrast with FIG. 1, an inlet 12 and an outlet 13 are provided in the reaction chamber 3, and these thus form two exchange connections 11. The inlet 12 allows the supply of ionic liquid 4 which can be fed in in reprocessed form from the reprocessing apparatus 16. The outlet 13 connects the water separator 1 and the reprocessing apparatus 16, such that the ionic liquid 4 can be fed, here for example by means of a pump 24, to the reprocessing in the reprocessing apparatus 16. In this case, more particularly, a particle filter 17 is provided downstream of the reaction chamber 3 or in the outlet 13, by means of which particles introduced by the water-containing working medium 2 are separable from the ionic liquid 4. In the reprocessing apparatus 16, a heating element 10 is provided, by means of which the ionic liquid 4 which can be introduced via the reprocessing inlet 25 can be heated, such that water is released in vaporous form and can be removed as water vapor 28 via a water outlet 9 of the reprocessing unit 16. The dried ionic liquid is then removed via the reprocessing outlet 26 and is fed in turn via a recycle conduit 27 and the inlet 12 to the reaction chamber 3. By contrast with FIG. 1, it is thus possible to execute a continuous separation and regeneration method, such that this water separator system 15 is especially suitable for continuous processes in which no interruption to the water separation is normally envisaged.

[0064] This method is as far as possible conducted such that a water-containing gaseous working medium 2 is fed to the reaction chamber 3 from beneath by the working medium inlet 5 and rises upward as a result of the lower density or a pressure maintained in the reaction chamber 3 and releases its water content to the ionic liquid as it does so. Subsequently, the dried gaseous working medium ascends out of the ionic liquid 4 and is removed via the clean medium outlet 6. The ionic liquid 4, by contrast, is continuously or alternately removed and heated, and hence the water content is separated out in vaporous form and the regenerated ionic liquid is fed back to the reaction chamber 3, preferably in cooled form.

[0065] In a first example of the invention, water is separated out of a natural gas-containing working medium 2 using one of the above-described ionic liquids, wherein the separation of water out of the working medium is conducted at a temperature in the reaction chamber in the range from +60 C. to +150 C. and a pressure in the reaction chamber 3 of 20 bar to 330 bar.

[0066] In a second example of the invention, water is separated out of a hydrogen-containing working medium 2 using one of the above-described ionic liquids, wherein the separation of water out of the working medium is conducted at a temperature in the reaction chamber 3 in the range from +60 C. to +160 C. and a pressure in the reaction chamber of 16 bar to 250 bar.

[0067] With the water separator proposed here and the corresponding method, it is possible with a reduced construction volume and with superatmospheric pressure to dry a water-containing working medium, optionally in a continuous manner.

TABLE-US-00001 List of reference numerals 1 Water separator 2 Water-containing working medium 3 Reaction chamber 4 Ionic liquid 5 Working medium inlet 6 Clean medium outlet 7 Dried working medium 8 Chamber wall 9 Water outlet 10 Heating element 11 Exchange connection 12 Inlet 13 Outlet 14 Coalescence filter 15 Water separator system 16 Reprocessing apparatus 17 Particle filter 18 Liquid level 19 Safety margin 20 Clean medium 21 Clean medium shutoff valve 22 Water shutoff valve 23 Screwholes 24 Pump 25 Reprocessing inlet 26 Reprocessing outlet 27 Recycle conduit 28 Water vapor 29 Lid (screw-connectable cylinder head)