The solubility of hydrogen sulphide (H2S) in aqueous solution of N-methyldiethanolamine (MDEA) in the presence of different mole ratios of 2-((2-aminoethyl)amino)ethanol (AEEA) at low and medium pressures was obtained. The total concentrations of all the solutions have been fixed equal 3.36 mol.L-1 (5.37 total moles of amines.kg(-1) water). The mole ratio of [AEEA]/[MDEA] (mole ratio of AEEA per MDEA in fresh solutions) was set to 0.05, 0.10 and 0.125. The experimental total pressure varied from (7.3 to 1500) kPa and the temperatures were set to (313.2, 328.2, 343.2 and 358.2) K. The experimental values are presented as the total pressure against acid gas loading (mole H2S/total moles of amine). The results show that the AEEA concentration can improve absorption capacity of MDEA aqueous solution as the mole ratio [AEEA]/[MDEA] increases at constant total concentration. The Deshmukh-Mather model and Peng-Robinson equation of state were used for liquid and vapour phases, respectively to correlate the solubility of H2S in aqueous mixtures of AEEA and MDEA. The overall average absolute percent deviation (AAD%) in calculating the total pressure as a function of H2S loading obtained 8.15% for (AEEA-MDEA-H2S-H2O) quaternary system at the entire temperature and pressure ranges in this work. (C) 2016 Elsevier Ltd. All rights reserved.