Quantification of oxygen transfer coefficients in simulated hydrocarbon-based bioprocesses in a bubble column...

This study investigates the overall volumetric oxygen transfer coefficient (K_La) in multiphase hydrocarbon-based bioprocess under a range of hydrocarbon concentrations (H_C), solid loadings (deactivated yeast) (S_L) and superficial gas velocities (U_G) in a bubble column reactor (BCR). K_La increased with increasing U_G in the air-water system; due to an increase in the number of small bubbles which enhanced gas holdup. In air-water-yeast systems, the initial addition of yeast increased K_La significantly. Further increases in S_L reduced K_La, due to increases in the bubble size with increasing S_L. K_La decreased when H_C was added in air-water-hydrocarbon systems. However, U_G, S_L and H_C affected K_La differently in air-water-yeast-hydrocarbon systems: an indication of the complex interactions between the yeast and hydrocarbon phases which changed the system's hydrodynamics and therefore affected K_L. This work illustrates the effect of the operating conditions (S_L, H_C and U_G) on oxygen transfer behaviour in multiphase systems.