Abstract
The rate-based model has been a rigorous model to capture carbon dioxide in packed column,so rate-based model for NH3-CO2-SO2-H2O system was developed. Using absorber and stripper to simulate the process of ammonia to capture carbon dioxide and we found that ammonia-water temperature has an effect on ammonia slip . The second part explores ammonia to capture carbon dioxide in the process of adding NH3 recycle unit to reduce NH3 emissions out of the absorber, and add washing column to the upper of the absorber. Flue gas discharged from Mumorah Power station passing by the pretreatment column to wash away the impurities contained in flue gas such as SOx, NOx ... etc.We combine the pretreatment column and wash column and find that ammonia slip has been controlled at 1.49~33ppm. Ammonia-water can be heated by flue gas latent heat to regenerate NH3 for recycling,thus saving significant amounts of energy.The proposed process has SO2 removal ratio >99.9% and NH3 reuse efficiencies of 99.68%. Besides,the process is strongly adaptable to different scenarios such as high SO2 level in flue gas and high ammonia-water recycle rate . The high SO2 level is beneficial for reducing NH3 emissions, because the acid gas SO2 dissolve into the solution,decreasing the pH value and facilitating the absorption of alkaline NH3 gas.But has a little effect on the CO2 capture unit energy comsuptions.The high ammonia-water recycle rate is also beneficial for reducing NH3 emissions,but it will increase the ammonia recovery unit chilling duty and heat duty.It’s also a little effect on the CO2 capture unit energy comsuptions. The third part is to investigate the branch liquid sulfur impurities split from ammonia recovery unit .Because ammonia react with sulfur dioxide producing ammonium bisulfite and ammonium sulfite (NH4HSO3/(NH4)2SO3) which is unstable and low added value.In order to produce high added value,we add the ozone oxidation process into the system to produce ammonia sulfate((NH4)2SO4).