AbstractAqueous ammonia, as an emerging, promising but challenging solvent for CO2 capture, has gained extensive interest over the last few years. Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) and Delta Electricity designed, constructed and commissioned an AU$ 7 million research scale pilot plant at the Munmorah black coal fired power station and used it to test an aqueous ammonia based post combustion capture process in 2009 and 2010. The results from the pilot plant trials were used to address the gap in know-how of the application of aqueous ammonia for post combustion capture of CO2 and other pollutants in the flue gas and to explore the potential of the ammonia process for application in the Australian power sector. This paper presents the results obtained and challenges identified from the pilot plant trials and identifies further research opportunities to improve the technology.