Abstract: | The volumetric mass transfer coefficient kLa in a 0.1 m‐diameter bubble column was studied for an air‐slurry system. A C9‐C11 n‐paraffin oil was employed as the liquid phase with fine alumina catalyst carrier particles used as the solid phase. The n‐paraffin oil had properties similar to those of the liquid phase in a commercial Fischer‐Tropsch reactor under reaction conditions. The superficial gas velocity UG was varied in the range of 0.01 to 0.8 m/s, spanning both the homogeneous and heterogeneous flow regimes. The slurry concentration ?S ranged from 0 to 0.5. The experimental results obtained show that the gas hold‐up ?G decreases with an increase in slurry concentration, with this decrease being most significant when ?S < 0.2. kLa/?G was found to be practically independent of the superficial gas velocity when UG > 0.1 m/s is taking on values predominantly between 0.4 and 0.6 s–1 when ?S = 0.1 to 0.4, and 0.29 s–1, when ?S = 0.5. This study provides a practical means for estimating the volumetric mass transfer coefficient kLa in an industrial‐size bubble column slurry reactor, with a particular focus on the Fischer‐Tropsch process as well as high gas velocities and high slurry concentrations. |