Carbon Dioxide Absorption to Sodium Hydroxide Glycerol Solution by a Rotating Packed Bed

Rotating packed bed (RPB) plays an important role in process intensification. The RPB substitutes the centrifugal force for gravitational force to enhance separation process. With the help of the centrifugal force, RPB can provide a wider operating range and better mass transfer efficiency. The absorption of carbon dioxide to sodium hydroxide glycerol/water solution in RPB was investigated. The gas and liquid flow rate, rotating speed, the concentration of sodium hydroxide, and glycerol weight percent were taken into consideration as operating variables to study the influence on absorption fraction, apparent overall volumetric mass transfer coefficient, and enhancement factor. According to experiment results, as the rotating speed, liquid flow rate, and the concentration of sodium hydroxide increased, absorption fraction, apparent overall volumetric mass transfer coefficient, and enhancement factor all increased. But these results were all decreased as gas flow rate increased. Moreover, adding 5 to 13 weight percent glycerol in sodium hydroxide solution could promote chemical absorption efficiency and raised absorption fraction at least 20% higher than sodium hydroxide aqueous solution. In this research, a correlation being applicable for chemical absorption and physical stripping/absorption is presented as: (K_G a)/(D_G a_t^2 ) (1-1.1 V_o/V_t )=0.006〖Re〗_G^0.1 〖Re〗_L^0.4 〖Gr〗_G^0.3 H_y^(-0.4) (1+C_NaOH )^3 (a_t/(a_p^'' ))^0.3