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US 2017/0361267 A1Published application
Method for the Recovery of Carbon Dioxide from an Absorbent with Reduced Supply of Stripping Steam
AssigneeUnion Engineering A/S
InventorsRasmus Find, Jan Flensted Poulsen
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Abstract
The present invention relates to a method for recovering carbon dioxide from an absorbent rich on gaseous carbon dioxide, in which the energy used for separation of absorbent and carbon dioxide in a stripping column is reduced by using two stripper columns having different operating pressures and recycling heat transfer fluid from the stripper off gas in an energy efficient manner.
Claims16
A method for recovering an acid gas from a liquid acid gas-rich absorbent (L1) comprising, the steps of:
- a. providing the liquid acid gas-rich absorbent (L1) having absorbed acid gas therein,
- b. separating the liquid acid gas-rich absorbent (L1) in a first liquid acid gas-rich fraction (L1_2) and a second liquid acid gas-rich fraction (L1_2);
- c. separating acid gas from the first fraction of the acid gas-rich absorbent stream (L1_1) in a first stripping column (A2_1) having a first pressure, p1, in order to provide a first acid gas-containing gas stream (G1_1) and a first liquid acid gas lean absorbent stream (L2_2);
- d. separating acid gas from the second fraction of the acid gas-rich absorbent stream (L1_2) in a second stripping, column (A2) having a second pressure, p2, using a gaseous stripping medium (G2) in order to provide a second acid gas-containing gas stream (G1_2) and a second liquid acid gas-lean absorbent stream (L2),
- e. mixing the compressed first acid gas-containing gas stream (G1_1) and the second acid gas-containing gas stream (G1_2) to provide a acid gas-containing gas stream (G1);
- f. transferring heat from the acid gas-containing gas stream (G1) to a stream of heat transfer fluid (L4) in order to provide a cooled acid gas-containing stream (G3) and a heated stream (L4);
- g. separating the heated stream (L4′) into a recovered gaseous stripping medium (G4) and a liquid heat carrier (L5);
- h. providing the recovered stripping medium (G4) directly or indirectly to the first stripping column (A2_1) having the first pressure, p1;
- wherein the first pressure, p1, is lower than the second pressure, p2.
6 more elements
Dependencies are inferred from the claim text.