The experimental results for CO2 absorption in aqueous tri sodium phosphate (TSP) were presented for total TSP concentrations from 1.0 to 2.0 kmol/m(3), temperatures from 303.14 to 333.14 K and inlet CO2 partial pressures from 10.13 to 20.26 kPa. The solubility of CO2 increased with increasing concentrations of TSP from 1.0 to 2.0 kmol/m(3) at fixed CO2 partial pressure and temperature. Temperature showed positive effect on CO2 solubility and it was increased continuously from 313.14 to 333.14 K. The solubility of CO2 also increased slightly with inlet partial pressure of CO2 in the gas stream. The maximum CO2 solubility in TSP was found as 0.960 mol CO2/mol absorbent at 333.14 K and 2.0 kmol/m(3) TSP concentration. The results of experimental CO2 solubility in aqueous TSP was compared to monoethanol amine (MEA) and other amines mostly used in acid gas treating. (C) 2012 Elsevier B.V. All rights reserved.