OVERALL VOLUMETRIC MASS-TRANSFER COEFFICIENT IN A MODIFIED REVERSED FLOW JET LOOP BIOREACTOR WITH LOW-DENSITY PARTICLES

Experiments were conducted using glass beads and low-density particles such as polyurethane and polystyrene which are comparable to bioparti cles found in biological applications to evaluate the overall volumetr ic mass transfer coefficient (K(L)a) in a modified reversed flow jet l oop bioreactor having the liquid outlet at the top section of the reac tor. The influence of the gas and liquid flow rates, draft tube to rea ctor diameter ratio, solids loading and physical properties of solids on K,a were studied. The K,a was found to increase with the increased gas and liquid flow rates. The K,a values were found to be higher in t he bubbly flow region i.e., at the lower range of energy dissipation r ates. The optimum draft tube to reactor diameter ratio and solids load ing with respect to maximum K(L)a were found to be 0.4 and 0.9 x 10(-3 ) m(3) (epsilon(s)=0.025) respectively. Dimensionless correlations wer e presented to predict the experimental values in terms of operational and geometrical variables.