Enhancement of oxygen absorption into sodium sulfite solutions

Abstract

AbstractOxygen absorption enhancement in a sodium sulfite solution was studied in the absence and presence of copper catalyst both for absorption across the liquid surface in a stirred cell and for absorption from individual bubbles rising through a turbulent liquid. The enhancement factor was determined from the ratio of oxygen and argon mass transfer coefficients, measured under identical experimental conditions in the same batch of liquid. It has been found that the oxygen absorption is not chemically enhanced, as long as the mass transfer coefficient, kL0, is high enough, i.e., higher than the value 1.4 × 10−4 m sec−1 for the sulfite solution we used. An analysis of our data as well as literature data indicates that the sulfite system is poorly suited for studies of the volumetric mass transfer coefficient of physical absorption (kL0a) in fermentors, inasmuch as oxygen absorption can be chemically enhanced while the degree of enhancement depends on the operating conditions of batch aeration, as well as on the concentration of trace impurities with catalytic effects upon the sulfite solution used.