Systems and methods for ammonia recovery, acid gas separation, or combination thereof
The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.
1 . A process comprising:
absorbing ammonia using a first aqueous solution comprising an acidic common ion salt to form a second solution comprising an ammonia-rich aqueous ammonia-common ion salt; and
absorbing carbon dioxide into the second solution under conditions to form a precipitate comprising an ammonia-carbon dioxide salt.
2 . The process of claim 1 wherein the acidic common ion salt comprises ammonium nitrate, or ammonium sulfate, or ammonium chloride.
3 . The process of claim 1 wherein the acidic common ion salt comprises ammonium acetate.
4 . The process of claim 1 wherein the conditions comprise cooling the second solution to a temperature to form the precipitate.
5 . The process of claim 1 further comprising filtering the precipitated ammonia-carbon dioxide salt.
6 . A process comprising:
absorbing ammonia using a first aqueous solution comprising an acidic common ion salt to form a second solution comprising an ammonia-rich aqueous ammonia-common ion salt; and
absorbing carbon dioxide into the second solution to form an ammonia-carbon dioxide salt.
7 . The process of claim 6 further comprising precipitating at least a portion of the ammonia-carbon dioxide salt.
8 . The process of claim 7 further comprising filtering the precipitated ammonia-carbon dioxide salt.
9 . The process of claim 7 wherein cooling is employed for the precipitating.
10 . The process of claim 7 wherein the acidic common ion salt comprises ammonium nitrate, or ammonium sulfate, or ammonium chloride.
11 . The process of claim 7 wherein the acidic common ion salt comprises ammonium acetate.