Recent developments in aqueous ammonia-based post-combustion CO2 capture technologies

Aqueous ammonia (NH3) is a promising alternative solvent for the capture of industrial CO2 emissions, given its high chemical stability and CO2 removal capacity, and low material costs and regeneration energy. NH3 also has potential for capturing multiple flue gas components, including NOx, SOx and CO2, and producing value-added chemicals. However, its high volatility and low reactivity towards CO2 limit its economic viability. Considerable efforts have been made to advance aqueous NH3-based post-combustion capture technologies in the last few years: in particular, General Electric's chilled NH3 process, CSIRO's mild-temperature aqueous NH3 process and SRI International's mixed-salts (NH3 and potassium carbonate) technology. Here, we review these research activities and other developments in the field, and outline future research needed to further improve aqueous NH3-based CO2 capture technologies. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.