Current status and challenges of the ammonia-based CO2 capture technologies toward commercialization

The present work reviews the current status and prospects of ammonia-based CO2 capture technology, an alternative to conventional amine-based CO2 capture technology. The absorption chemistry and engineering issues for the process development and commercialization are dealt with. Representative developers at pilot-scale testing are Alstom, Powerspan, Commonwealth Scientific and Industrial Research Organization, and Research Institute of Industrial Science & Technology, while lab- and bench-scale studies have at Korea Institute of Energy Research, Tsinghua University and Norwegian University of Science & Technology, etc. Published works on CO2 capture using aqueous ammonia state the removal efficiency of CO2 can be 90% and the product purity exceeds 98%, implying that the technical feasibility has been proven. Although being said that it is in the pre-stage of commercialization, some technical issues including the ammonia slip should be resolved to secure economic plausibility. Suggestions are made for the successful development of ammonia-based CO2 capture process for commercialization: suppression of ammonia vaporization, heat integration, minimization of absorbent flow rate, and bicarbonate-prevalent operation.