Method to Regenerate Ammonia for the Capture of Carbon Dioxide

Compared to the conventional MEA process for the capture of carbon dioxide from flue gas, the ammonia scrubbing technique provides advantages of lower material costs and less corrosion to absorber, as well as the potential for saving energy, which will eventually make the process less expensive. However, in addition to the highly volatile nature of ammonia, the lack of a method to separate ammonia from CO2 after thermal decomposition of ammonium bicarbonate also hinders the ammonia scrubbing technique from being applied in practice. This paper investigates a method to regenerate ammonia so as to allow for the ammonia scrubbing technique to be practical in the capture of CO2. In the new method, a weakly basic ion-exchange resin containing amine functional groups is used to regenerate ammonia through absorbing carbonic acid at ambient temperatures from ammonium bicarbonate, the main product formed after the absorption of CO2 by ammonia. The resin can then be regenerated when it is heated by water at tempera...