The integrated gasification combined cycle (IGCC) is getting much more attention due to the rich reserves of coal around the world. In general, the absorption rate of a physical method such as the IGCC system is weaker than that of a chemical method, but it needs much less energy during the regeneration process. In this study, the main objective is to estimate the performance enhancement for CO2 gas absorption and regeneration by using SiO2/DI water and Al2O3/DI water nanofluids. The key parameters are the concentrations of SiO2 and Al2O3 nanoparticles and the system pressure during the regeneration process. It is found that the maximum CO2 absorption and regeneration performance enhancements are 23.5% and 11.8% at 0.01 vol% of SiO2 nanoparticles, respectively. However, in the case of Al2O3 nanoparticles, the CO2 absorption performance increases 23.5% at 0.01 vol%, but the regeneration performance decreases 11.2% at 0.01 vol%, respectively. The enhancement mechanisms for CO2 absorption and regeneration by nanoparticles are summarized and proposed in this study. (C) 2015 Elsevier Ltd. All rights reserved.