An activated solution based on amino acid salt was proposed as a CO2 absorbent. Piperazine (PZ) was selected as an activating agent and added into the aqueous glycine salt to form the activated solution. A coupling process, which associated the activated solution with a PP hollow fiber membrane contactor, was set up. An experimental and theoretical analysis for CO2 capture was performed. The performances of CO2 capture by the coupling process were evaluated using the PZ activated solution and the non-activated glycine salt solution. A numerical model for the simulation of the hollow fiber membrane gas-liquid mass transfer was developed. Typical parameters such as outlet gas phase CO2 concentration, capture efficiency, and mass transfer coefficient for the activated solution were determined experimentally. The effects of operation temperature and liquid CO2-loading on mass transfer coefficient and capture efficiency were discussed in this work. Axial and radial concentration profiles of CO2 in the fiber lumen and mass transfer flux were simulated by the model. Results show that the performances of the PZ activated glycine salt solution are evidently better than that of the non-activated glycine salt solution in the membrane contactor for CO2 capture. Elevation of the operation temperatures can enhance the overall mass transfer coefficient. The activated solution can maintain higher capture efficiency especially in the case of high CO2-loadings. The gas phase CO2 concentration with the activated solution is lower than that with the non-activated solution whether along axial or radial distances in the fiber lumen. The model simulation is validated with experimental data.