Present research work is focused on the analysis of carbon dioxide chemical absorption with tri-nbutylamine (TBA) due to the suitable behavior previously shown by some tertiary amines (mainly methyldiethanolamine). TBA has a negative characteristic due to its low solubility in water that implies the use of an organic co-solvent using several alcohols in present work. Ethanol showed the best experimental results in carbon dioxide absorption rate and loading. A decrease in carbon dioxide loading in comparison with tertiary amines in aqueous solution was observed due to the high chemical interactions between water and ethanol molecules. It was confirmed using monoethanolamine + water + ethanol as chemical solvent and its comparison with the liquid phase in the absence of ethanol. A very important issue for TBA-solvent is the dramatic decrease in solvent degradation under stripping experimental conditions. This fact reduces until a minimum the solvent make-up flow-rate with a very important decrease in the overall process cost. (C) 2018 Elsevier Ltd. All rights reserved.