The absorption of carbon dioxide from nitrogen-carbon dioxide mixture was investigated in a hollow fiber membrane module using methyldiethanolamine/monoethanolamine (MDEA/MEA) aqueous solutions and distilled water. The experimental results showed that both the CO2 absorption flux and fractional removal increased with increasing content of MEA in mixed amines and increasing liquid flow rate. For the non-wetted operation mode, a mathematical model to simulate the behavior Of CO2 removal by mixed amines in hollow fiber modules was developed and solved. The simulation results agreed well with the experimental data. Moreover, approximate solution using conventional mass transfer models also validates the availability of the mathematical model. Theoretical results also indicate the depletion of MEA is much greater than that of MDEA during the CO2 absorbed in mixed amines. (c) 2006 Elsevier B.V. All rights reserved.