A dimensionless model for predicting the mass‐transfer area of structured packing

The mass‐transfer area of nine structured packings was measured in a 0.427 m ID column via absorption of CO 2 from air into 0.1 kmol/m 3 NaOH. The mass‐transfer area was most strongly related to the specific area (125–500 m 2 /m 3 ), and liquid load (2.5–75 m 3 /m 2 ·h). Surface tension (30–72 mN/m) had a weaker but significant effect. Gas velocity (0.6–2.3 m/s), liquid viscosity (1–15 mPa·s), and flow channel configuration had essentially no impact on the mass‐transfer area. Surface texture (embossing) increased the effective area by 10% at most. The ratio of mass‐transfer area to specific area ( a e / a p ) was correlated within the limits of ±13% for the entire experimental database ${{a_{\rm{e}} } \over {a_{\rm{p}} }}= 1.34 \left[ {\left( {{{\rho _{\rm{L}} } \over \sigma }} \right)g^{1/3} \left( {{Q \over {L_{\rm{p}} }}} \right)^{4/3}} \right]^{\,0.116}$ . © 2010 American Institute of Chemical Engineers AIChE J, 2010