METHOD AND ARRANGEMENT FOR SEPARATING CARBON DIOXIDE FROM A FEED STREAM CONTAINING CARBON DIOXIDE

Abstract

A process is proposed for separating carbon dioxide from a feed stream containing carbon dioxide, in which at least part of the feed stream is subjected to temperature swing adsorption to obtain a first and a second successive stream, wherein, in each case relative to the feed stream, the first subsequent stream is depleted in carbon dioxide and the second subsequent stream is enriched in carbon dioxide, and at least part of the second subsequent stream is subjected to membrane separation to obtain a third and a fourth subsequent stream, the third subsequent stream being depleted in carbon dioxide and the fourth subsequent stream being enriched in carbon dioxide, in each case relative to the second subsequent stream. A corresponding arrangement is also an object of the invention.

Claims

1. A method for the separation of carbon dioxide from a carbon dioxide-containing feed stream, wherein at least a part of the feed stream is subjected to a temperature swing adsorption to obtain a first and a second successive stream, the first successive stream being depleted in carbon dioxide and the second successive stream being enriched in carbon dioxide, in each case in relation to the feed stream, and at least a part of the second successive stream is subjected to a membrane separation to obtain a third and a fourth successive stream, the third successive stream being depleted in carbon dioxide and the fourth successive stream being enriched in carbon dioxide, in each case relative to the second successive stream, wherein at least a part of the fourth successive stream is subjected to a compression and partial liquefaction in a heat exchanger to obtain a gaseous and a liquid fraction, the gaseous fraction being depleted in carbon dioxide and the liquid fraction being enriched in carbon dioxide, in each case relative to the fourth subsequent flow, at least a part of the gaseous fraction is again subjected to the temperature swing adsorption together with the feed stream and at least part of the liquid fraction is subjected to an expansion and used as refrigerant in a heat exchanger for partial liquefaction.

2. The method according to claim 1, in which a content of carbon dioxide in the feed stream is 5 0.1 to 2 mole percent or 0.1 to 5 mole percent and/or in the first successive stream is 0.0001 to 1 mole percent or 0.001 to 0.1 mole percent and/or in the second successive stream is 0.5 to 10 mole percent and/or in the third successive stream is 0.5 to 5 mole percent and/or in the fourth successive stream is 50 to 90 mole percent and/or in the gaseous fraction is 20 to 70 or 30 to 80 mole percent and/or in the liquid fraction is 90 to 99.999 mole percent.

3. The method according to claim 1, wherein the feed stream is formed using natural gas.

4. The method according to claim 3, wherein the feed stream is withdrawn from a natural gas pipeline and at least a portion of the first successive stream is fed back into the natural gas pipeline.

5. The method according to claim 3, wherein at least a portion of the first successive stream is subjected to a liquefaction.

6. The method according to claim 1, wherein the heat exchanger used in the partial liquefaction is a plate heat exchanger.

7. The method according to claim 1, wherein the feed stream comprises methane and one or more further components selected from water and hydrocarbons boiling higher than methane, ethane or propane, and wherein, in each case relative to the feed stream, the first successive stream is depleted in the one or more further components and the second successive stream is enriched in the one or more further components.

8. The method according to claim 1, wherein a portion of the first successive stream is used to regenerate an adsorbent in the temperature swing adsorption.

9. The method according to claim 8, wherein the regeneration of the adsorbent is carried out at a temperature of 100 to 300 ° C.

10. An arrangement for separating carbon dioxide from a feed stream containing carbon dioxide and configured to subject at least a part of the feed stream to a temperature swing adsorption to obtain a first and a second successive stream, the first successive stream being depleted in carbon dioxide and the second successive stream being enriched in carbon dioxide, in each case relative to the feed stream, and subject at least a part of the second successive stream to a membrane separation to obtain a third and a fourth successive stream, the third successive stream being depleted in carbon dioxide and the fourth successive stream being enriched in carbon dioxide, in each case relative to the second successive stream, wherein means that are configured to subject at least a part of the fourth successive stream to a compression and a partial liquefaction to obtain a gaseous and a liquid fraction, the gaseous fraction being depleted in carbon dioxide and the liquid fraction being enriched in carbon dioxide, in each case relative to the fourth successive stream, and subject at least a part of the gaseous fraction together with the feed stream to a temperature swing adsorption and subject at least part of the liquid fraction to an expansion and use it as refrigerant in a heat exchanger used in the partial liquefaction.

11. An arrangement according to claim 10, which is configured to perform a method for the separation of carbon dioxide from a carbon dioxide-containing feed stream, wherein the method comprises the steps of: at least a part of the feed stream is subjected to a temperature swing adsorption to obtain a first and a second successive stream, the first successive stream being depleted in carbon dioxide and the second successive stream being enriched in carbon dioxide, in each case in relation to the feed stream, and at least a part of the second successive stream is subjected to a membrane separation to obtain a third and a fourth successive stream, the third successive stream being depleted in carbon dioxide and the fourth successive stream being enriched in carbon dioxide, in each case relative to the second successive stream, wherein at least a part of the fourth successive stream is subjected to a compression and partial liquefaction in a heat exchanger to obtain a gaseous and a liquid fraction, the gaseous fraction being depleted in carbon dioxide and the liquid fraction being enriched in carbon dioxide, in each case relative to the fourth subsequent flow, at least a part of the gaseous fraction is again subjected to the temperature swing adsorption together with the feed stream and at least part of the liquid fraction is subjected to an expansion and used as refrigerant in a heat exchanger for partial liquefaction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 illustrates a method and at the same time an arrangement according to one embodiment of the present invention.

DETAILED DESCRIPTION

[0042] The invention is further explained below with reference to the accompanying drawing, which illustrates one embodiment of the present invention.

[0043] FIG. 1 illustrates a method and at the same time an arrangement according to one embodiment of the present invention.

[0044] In the FIGURE, where applicable, structurally or functionally corresponding elements are illustrated with identical reference signs and are not explained repeatedly for the sake of clarity. If components of a device or arrangement are explained below, the corresponding explanations also relate to a process carried out with it and vice versa.

[0045] FIG. 1 illustrates a process for separating carbon dioxide from a feed stream containing carbon dioxide in accordance with an embodiment of the invention, wherein the process as a whole is designated 100 and the feed stream is designated E.

[0046] In the embodiment illustrated in FIG. 1, at least a portion of the feed stream E is subjected to temperature swing adsorption 10 in the manner described in more detail above to obtain a first and a second successive stream 1, 2, wherein, in each case relative to the feed stream E, the first successive stream 1 is depleted in carbon dioxide and the second successive stream 2 is enriched in carbon dioxide. Furthermore, in the embodiment illustrated in FIG. 1, at least part of the second successive stream 2 is subjected to membrane separation 20 in the manner described in more detail above, while obtaining a third and a fourth successive stream 3, 4, the third successive stream 3 being depleted in carbon dioxide and the fourth successive stream 4 being enriched in carbon dioxide, in each case relative to the second successive stream 2.

[0047] As further illustrated in FIG. 1 and explained in more detail above, at least part of the fourth successive stream 4 is subjected to compression 30 and partial liquefaction and phase separation in units commonly referred to with 40 to obtain a gaseous and a liquid fraction 5, 6, wherein, relative to the fourth successive stream, the gaseous fraction 5 is depleted in carbon dioxide and the liquid fraction 6 is enriched in carbon dioxide. The partial liquefaction takes place in the heat exchanger 41 forming a biphasic stream and the overall process comprises passing the fourth successive stream 4, or a portion thereof, after compression 30, through the heat exchanger 41 and thereafter into a phase separation 42 where said phases are separated.

[0048] In addition, at least part of the gaseous fraction 5 is again subjected to temperature swing adsorption 10 together with the feed stream E and at least part of the liquid fraction 6 is subjected to expansion 43 and used as refrigerant in a heat exchanger 41 for partial liquefaction.

[0049] In the embodiment of the process 100 illustrated herein, the feed stream E is formed using natural gas by taking the feed stream E from a natural gas pipeline NG. At least a portion of the first successive stream 1 may thereby be subjected to liquefaction 50 to obtain liquefied natural gas LNG. However, as illustrated in the form of a dashed arrow, it is also possible to feed back at least part of the first successive stream 1 into the natural gas pipeline NG.

[0050] As indicated by 11 in FIG. 1 as a whole, a portion of the first successive stream 1 may be used to regenerate an adsorbent in the temperature swing adsorption 10 by compressing and heating it.

[0051] In all embodiments, at least a portion of the third successive stream 3 may also be recycled to the temperature swing adsorption 10.