Simulations On The Operation And Adjustment Of The Combined Removal Of CO₂ And SO₂ Process Based On Aqueous Ammonia

Aqueous ammonia,a new absorbent used in carbon capture and storage,has seen promising application in the combined removal of CO₂ and SO₂ in flue gas from coal-fired power plants.The ammonia-based combined removal technology has been extensively studied by simulation,and by experiment with a pilot scale plant.This study dealt with a highly complex and highly coupled combined removal process,in order to develop the methodology for operation,adjustment,and optimization of the process.The techno-economic performance of the process when applied to large-scale power plants was also demonstrated.The models of physical properties and chemical reactions of the process were developed and verified based on pertinent studies.Design parameters determined in accordance with the pilot plant,further explored were the operating profiles of core components,in which all relevant operating parameters'influence on performance indicators were examined for each component.Furthurmore,some of the key parameters were optimized during the process,the liquid flow rate in desulfurization cycle being 800kg/h while the flow rate,ammonia concentration,CO₂ loading of the lean flow in decarburization being 4000 kg/h,5 wt%and 0.2 mol/mol NH₃ respectively.A full solution to the operation and adjustment of the process was developed.This study also developed a technique to characterize the operation of the process,in which the optimized operating interval can be identified.Presented in the operation and adjustment solution were the selection of initial parameters,the adjustment to optimized interval,the adaptability to fluctuation,fine-tuning during the accumulation of byproducts,and the disposal of byproducts.The techno-economic performance of the process when applied to a 650 MW coal-fired power plant was evaluated and compared to the process optimized by employing rich-split configuration.The net power generation efficiency decreased from 38.9%to24.7%and 24.2%respectively when the process and the optimized process were adopt,and the levelized cost of electricity soared from 64.5$/?MWh?to 141.7 and 131.0$/?MWh?,with a corresponding CO₂ avoided cost of 99.6 and 88.3$/t CO₂.