SYSTEMS & 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 for separating or recovering basic gases comprising:
(a) absorbing ammonia from an ammonia containing gas stream into an ammonia-lean, an ammonia-ultra-lean, or ammonia free solution, to form an ammonia-rich solution; (b) enriching said ammonia-rich solution with one or more acid gases to form an ammonia-rich, acid gas rich solution; and
(c) concentrating said ammonia-rich, acid gas rich solution using one or more membranes to form a first retentate and a permeate wherein said permeate is suitable for use as at least a portion of the ammonia-ultra-lean or ammonia-free solution in step (a); and
(d) adding said first retentate to a larger volume of ammonia-acid gas solution to form a first combined solution; and
(e) further concentrating said first combined solution using a membrane to form a second retentate and a second permeate wherein the second permeate comprises an amount of water that is the same or greater than an amount of water in the first retentate.