Determination of Mass-Transfer Coefficient of CO2in NH3and CO2Absorption by Materials Balance in a Rotating Packed Bed

Abstract

More-accurate overall mass-transfer coefficients in a rotating packed bed (RPB) and local mass-transfer coefficients in different regions of the RPB were deduced by the material balance in order to obtain practical volumetric mass-transfer coefficients in the RPB. Experimental studies on the overall volumetric mass-transfer coefficients (KGa) of CO2 in NH3 and CO2 absorption into water in the RPB was carried out under different conditions. The experimental results indicated that there was a great difference between the value of KGa and KGa* attained by different boundary conditions. And it was concluded that an accurate design equation should be adopted to achieve a practical value of KGa in the RPB. It was also found that the KGa of CO2 increased with the increase of rotation speed, liquid volumetric flow rate, gas volumetric flow rate, NH3/CO2 molar ratio, and the decrease of temperature. The KGa of CO2 in the simultaneous absorption process of NH3 and CO2 was 2–6 times higher than that in the single CO2 absorption process.