Suggestions for controlling ammonia concentration

https://doi.org/10.1016/j.seppur.2021.118959

“Furthermore, the NH₃ concentration in the CO₂ gas stream generated in the CO₂ desorber has to be limited, aiming at: (i) avoiding solid formation in the condensate streams generated downstream, i.e. either in the condenser of the CO₂ desorber [13], [25], or during CO₂ compression [13]; and, (ii) limiting pipeline corrosion during CO₂ transportation [26]. The introduction of the Rich Solvent Splitting (RSS), i.e. a split of the cold CO₂-rich stream that bypasses the rich/lean heat exchanger and that is fed to the top of the CO₂ desorber, has been found to be an efficient and cost effective solution that: (i) improves the energetic performance of NH₃-based capture processes, (ii) limits the NH₃ slip in the CO₂ gas stream, and (iii) avoids the use of a condenser in the CO₂ desorber, thus avoiding the formation of solids in the resulting condensate [4], [14], [27]. NH₃ is normally further removed from the CO₂ gas stream by scrubbing, using water as washing medium [3], [14], [18], [28], in order to meet the concentration limits of impurities for CO₂ transportation.”