Method for reducing regeneration energy

Patent metadata

Field	Value
Publication number	US-9522359-B2
Application number	US-201113981227-A
Country	US
Kind code	B2
Filing date	Sep 16, 2011
Priority date	Feb 2, 2011
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A process and an apparatus are described, which remove acid gas from a gas stream in a manner that generates a product gas stream at a higher temperature while consuming less energy than the existing technology. The process requires maintaining a positive product gas temperature differential. The apparatus enables the positive gas temperature differential to be maintained by manipulating the absorber column operating conditions and/or the solvent chemistry to increase the amount of absorption and reaction in the absorber.

First claim

What is claimed is:

1. A method of removing acid gases from a gas stream, comprising the steps of:
providing an absorber column;
providing the gas stream to the absorber column;
providing a lean solvent solution stream comprising an aqueous amine-based solvent solution to the absorber column;
contacting the gas stream and the lean solvent solution stream in the absorber column to produce a product gas depleted of acid gases and a rich solvent solution;
measuring a product gas temperature of the product gas in the absorber column at a first location proximal to where the lean solvent solution stream first contacts the gas stream;
measuring a lean solvent temperature of the lean solvent solution stream at a second location proximal to where the lean solvent solution stream first contacts the gas stream;
providing a regenerator;
providing the rich solvent solution to the regenerator to produce a regenerated solvent solution stream;
providing a heating unit wherein the regenerated solvent solution stream from the regenerator is heated by heat exchange relationship with heating fluid from the heating unit;
adjusting at least one of the lean solvent temperature, a recirculation rate of the lean solvent solution stream, and a solvent-to-water ratio of the lean solvent solution stream to result in a product gas temperature elevation greater than 5° C., thereby reducing regeneration energy, wherein the product gas temperature elevation is the difference between the product gas temperature and the lean solvent temperature; and
discharging a product gas stream of the product gas from the absorber column.

2. The method according to claim 1 , wherein the gas stream comprises a flue gas.

3. The method of claim 1 wherein the product gas stream discharged from the absorber column is depleted of CO 2 gas when compared to the provided gas stream.

4. The method of claim 1 further comprising measuring at least one operational parameter selected from the group consisting of the recirculation rate of the lean solvent solution stream and the solvent-to-water ratio of the lean solvent solution stream.

5. The method according to claim 1 , wherein the solvent-to-water ratio is adjusted to adjust the product gas temperature elevation.

6. The method of claim 5 , wherein the product gas temperature elevation is increased by increasing the solvent-to-water ratio.

7. The method according to claim 1 , wherein the solvent solution circulation rate is adjusted to adjust the product gas temperature elevation.

8. The method according to claim 7 wherein the product gas temperature elevation is increased by decreasing the solvent solution circulation rate.

9. The method of claim 1 , wherein the lean solvent temperature is adjusted to adjust the product gas temperature elevation.

10. The method according to claim 9 , wherein the product gas temperature elevation is increased by increasing the lean solvent temperature.

Assignees

• Vitse Frederic
• Schubert Craig Norman
• General Electric Technology Gmbh
• Dow Global Technologies Llc

Inventors

• Vitse Frederic
• Schubert Craig Norman

Classifications

• B01D53/1462 Primary

  Removing mixtures of hydrogen sulfide and carbon dioxide · CPC title

• B01D53/346

  Controlling the process · CPC title

• B01D53/1412 Primary

  Controlling the absorption process · CPC title

• B01D2252/20489

  with two or more hydroxyl groups · CPC title

• Y02C10/06

  Cross-Sectional Technologies · mapped topic