System and method for recovering ammonia from a chilled ammonia process
View Patent ↗An ammonia recovery system and method for removing ammonia from a gas stream is provided. The system includes an ammonia recovery vessel for contacting a solution, having a dissolved acidic salt, with the gas stream, having ammonia. The dissolved acidic salt solution absorbs the ammonia in the gas stream to provide an ammonia-lean gas stream and an ammonia-rich solution. The ammonia-rich solution is heated within an ammonia stripper to release the ammonia from the ammonia-rich solution to thereby generate an ammonia-rich gas stream and the solution having dissolved acidic salt. A heat exchanger heats the dissolved acidic salt from the ammonia stripper prior to the solution being provided to the ammonia recovery system. The acidic salt has a low thermal decomposition.
1. An ammonia recovery system for removing ammonia from a gas stream, the system comprising:
an ammonia recovery vessel for contacting a solution having a dissolved acidic salt with the gas stream having ammonia wherein the dissolved acidic salt solution absorbs the ammonia in the gas stream to provide ammonia-lean gas stream and an ammonia-rich solution;
an ammonia stripper including a vessel that receives and heats the ammonia-rich solution from the vessel to release the ammonia from the ammonia-rich solution to generate an ammonia rich gas stream comprising ammonia and water, and the solution having dissolved acidic salt;
a heat exchanger for receiving the dissolved acidic salt solution from the ammonia stripper and heating the solution prior the solution being provided to the ammonia recovery vessel;
wherein the acidic salt has a low thermal decomposition temperature.
2. The ammonia recovery system of claim 1 , further includes a second heat exchanger for heating the ammonia-rich solution prior to entering the ammonia stripper.
3. The ammonia recovery system of claim 1 , further includes a second heat exchanger that exchanges heat from the ammonia-lean solution from the ammonia stripper with the ammonia-rich solution provided to the ammonia stripper.
4. The ammonia recovery system of claim 1 , wherein the acidic salt has a thermal decomposition temperature between 50 and 300 degrees Celsius.
5. The ammonia recovery system of claim 1 , wherein the acidic salt includes at least one of ammonium acetate and ammonium phosphate.
6. The ammonia recovery system of claim 1 , further includes a carbon capture system having an absorption vessel that contacts the gas stream with a chilled solution having ammonia to absorb CO 2 from the flue gas stream to generate a CO 2 rich solution and the gas stream having ammonia.
7. The ammonia recovery system of claim 1 , wherein the gas stream is a flue gas stream from a combustion process.
8. The ammonia recovery system of claim 6 , further includes a regeneration vessel for receiving the CO 2 rich solution and heating the solution to provide a CO 2 rich gas stream and a CO 2 lean absorption solution which is recycled back to the absorber vessel.
9. The ammonia recovery system of claim 1 , further comprising a direct contact cooling vessel for cooling the gas stream prior to entering the absorption vessel.
10. The ammonia recovery system of claim 9 , further comprising a pipe to provide the water from the direct contact cooling vessel to the second heat exchanger to preheat the ammonia-lean solution from the ammonia stripper prior to entering the ammonia recovery vessel.
11. A method of removing ammonia from a gas stream, the method comprising:
contacting within a first vessel a solution having a dissolved acidic salt with the gas stream having ammonia wherein the dissolved acidic salt solution absorbs the ammonia in the gas stream to provide ammonia-lean gas stream and an ammonia-rich solution;
heating within a second vessel the ammonia-rich solution to release the ammonia from the ammonia-rich solution to generate an ammonia rich gas stream comprising ammonia and water, and a solution having dissolved acidic salt;
heating the dissolved acidic salt solution;
providing the heated dissolved acidic salt solution back to the first vessel;
wherein the acidic salt has a low thermal decomposition temperature.
12. The method of claim 11 , further comprising heating the ammonia-rich solution prior to entering the second vessel.
13. The method of claim 11 , further comprising exchanging heat from the ammonia-lean solution from the second vessel with the ammonia-rich solution provided to the second vessel.
14. The method of claim 11 , wherein the acidic salt has a thermal decomposition temperature between 50 and 300 degrees Celsius.
15. The method of claim 11 , wherein the acidic salt includes at least one of ammonium acetate and ammonium phosphate.
16. The method of claim 11 , further comprising contacting in a third vessel the gas stream with a chilled solution having ammonia to absorb CO 2 from the flue gas stream to generate a CO 2 rich solution and the gas stream having ammonia.
17. The method of claim 11 , wherein the gas stream is a flue gas stream from a combustion process.
18. The method of claim 16 , further comprising heating the CO 2 rich solution to provide a CO 2 rich gas stream and a CO 2 lean absorption solution which is recycled back to the third vessel.
19. The method of claim 16 , further comprising cooling in a fourth vessel the gas stream prior to entering the third vessel.
20. The method of claim 19 , further comprising providing water from the fourth vessel to preheat the ammonia-lean solution from the second vessel prior to entering the first vessel.