The mass transfer performance of CO2 absorption into blended DEEA/MEA solutions was investigated in a lab-scale absorber packed with Sulzer DX structured packing using a standard orthogonal array with an L-25(5(6)) matrix. The volumetric overall mass transfer coefficient (K(G)a(V)) was evaluated at various key operating conditions over a amine concentration range of 2.00-5.00 kmol/m(3), CO2 lean loading of 0.15-0.35 mol CO2/mol amine, over a wide CO2 partial pressure range of 6-18 kPa, a liquid feed temperature range of 303.15-343.15 K, with liquid flow rate 3.90-11.70 m(3)/m(2).h, and 30.47-47.87 kmol/m(2).h inert gas flow rate. The results show that these key operating parameters have significant effects on K(G)a(V). Also, based on orthogonal analysis, it was clear that the order of importance for the contribution to KGav of the six investigated factors was as follows: CO2 lean loading > CO2 partial pressure > Liquid feed temperature > Amine concentration > Liquid flow rate > Inert gas flow rate and the optimization of the experimental combination was B(1)C(1)D(2)A(3)E(3)F(2). (C) 2017 Published by Elsevier B.V.