The absorption capacity of CO2 in piperazine (PZ) promoted 2-diethylaminoethanol (DEAE) aqueous solution was measured. The viscosities of both CO2-unloaded and CO2-loaded PZ-DEAE aqueous solutions were measured and then modelled. The temperatures ranged from 303.2 K to 323.2 K. The mass fraction of PZ and DEAE respectively ranged from 0 to 0.075 and 0.3 to 0.5. The temperature and concentration dependences of absorption capacity were determined. The effects of temperature, mass fraction and CO2 loading on viscosities are demonstrated. (C) 2016 Elsevier Ltd.