Technical and Energy Performance of an Advanced, Aqueous Ammonia-Based CO₂ Capture Technology for a 500 MW Coal-Fired Power Station

Abstract

Using a rate-based model, we assessed the technical feasibility and energy performance of an advanced aqueous-ammonia-based postcombustion capture process integrated with a coal-fired power station. The capture process consists of three identical process trains in parallel, each containing a CO2 capture unit, an NH3 recycling unit, a water separation unit, and a CO2 compressor. A sensitivity study of important parameters, such as NH3 concentration, lean CO2 loading, and stripper pressure, was performed to minimize the energy consumption involved in the CO2 capture process. Process modifications of the rich-split process and the interheating process were investigated to further reduce the solvent regeneration energy. The integrated capture system was then evaluated in terms of the mass balance and the energy consumption of each unit. The results show that our advanced ammonia process is technically feasible and energy-competitive, with a low net power-plant efficiency penalty of 7.7%.

Systematic study of aqueous monoethanolamine‐based CO2 capture process: model development and process improvement

“…The cold rich stream was split to recover the energy contained in the upcoming high temperature water vapor; meanwhile the rich solvent was heated to release part of the CO 2 . This process has proven to be effective in process simulations as well as in the Tarong pilot plant trials . In this study, the unsplit stream was introduced at the stage 5 (20 stages in total) after crossing the heat exchanger while the split stream was fed to the top of the stripper.…”

Renewable absorbents for CO2 capture: from biomass to nature

“…Compared to the benchmark absorbent − MEA, ammonia has several advantages, such as a lower heat requirement for CO 2 desorption, no absorbent degradation, low absorbent cost, and capacity for simultaneous removal of CO 2 and SO 2 from flue gas. Therefore, aqueous ammonia solution (AA) can be used as an alternative absorbent for CO 2 capture from flue gas, and research on pilot plants has been carried out . Ammonia is also an essential feedstock for chemical engineering and fertilizer for crop production.…”

Process enhancement in aqueous ammonia PCC using a direct contact condenser

“…Subsequently, this change will affect the absorption equilibrium in the absorber and eventually the rich loading. Li et al . have optimized the rich‐split fraction for aqueous ammonia PCC pilot‐plant trials and reported that, at 5% rich‐split fraction, the regeneration duty can be reduced from 3.27 to and the condensate duty dropped from 1.45 to .…”

“…This reduction includes 11.6% in the reboiler duty and 73.1% for the condenser. According to Li et al ., increasing the rich‐split fraction will substantially reduce the heat of vaporization and subsequently the condenser duty, but would also noticeably increase the sensible heat and the reboiler duty. For example, at a 10% rich‐split fraction, the reboiler duty was even higher than the conventional reboiler duty by 1.8%, while the condenser duty was substantially reduced by 94.4%.…”