Explorative analysis of advanced solvent processes for energy efficient carbon dioxide capture by gas-liquid absorption

CO2 capture by gas-liquid absorption needs solvents able to overcome existing barriers for wide-scale adoption including high energy requirement, slow reaction rate, insufficient CO2 loading capacity, solvent degradation and corrosiveness, poor selectivity or limited operating window. It is challenging if not impossible for single or blended solvents to satisfy all these requirements and reach technology readiness level sufficient for economically viable deployment in large-scale CO2 capture systems, especially in the energy sector. Therefore, innovative advanced solvent processes (ASPs) attract attention as a new technology that may overcome existing barriers in CO2 capture by gas-liquid absorption. Due to significant research funding in the area of advanced solvent processes over a few recent years many new ASPs have been developed. Thus this study delivers an explorative analysis of ASPs suitable for energy efficient CO2 capture by gas-liquid absorption. The emphasis is put on ASPs such as two immiscible liquid phases, precipitating solvents, catalysed solvents, microencapsulated solvents, liquid membrane solvents, ionic liquids, and polarity-swing-assisted solvents. The analysis shows that some of recently developed ASPs made huge progress in terms of reduced energy requirement for capturing CO2. However, most advanced solvent processes have insufficient technology readiness level and, in addition, there is still place for further energy efficiency improvement. Therefore, research efforts capable of bringing ASPs to commercialisation and wide-scale adoption in real large-scale CO2 capture applications are required in next few years. (C) 2016 Elsevier Ltd. All rights reserved.