Bioreactor engineering allows modeling the conditions of real life biological processes. Particularly, oxygen represents one of the most important factors for life, and the understanding and control of its mass transfer in bioreactors is one of the most challenging problems in the industry. The aim of this study was to develop an optical approach for measuring the oxygen mass transfer coefficient (k La). An assembly was constructed for this purpose, consisting of a stirred tank bioreactor, a high-intensity light source, a luminometer and a digital camera. Air flux supply and stirring velocity of the bioreactor were tested over a range of thirty-five values. The air bubbles generated were counted and their diameters were measured from photographs. The luminometer measured light obstruction due to bubbles. A polarography electrode sensor measured the dissolved oxygen in water to correlate it with the optical approach. The results showed a close correlation between k La and light obstructed due to bubbles of air. The bubble diameter and holdup results suggest that the size of the bubbles decreases and becomes more homogeneous as stirring speed increases. A multivariable linear model for k La as a function of the measured light obstruction and air flux injection was constructed. A strong correlation between this model and results was obtained. This approach avoids the need for chemical sensors for sensing systems, with a noninvasive and nondestructive methodology to determine the k La for dilute solutions. This technique could be developed to evaluate a scaled-up bioreactor before running a bioprocess.
|Journal||International Journal of Chemical Reactor Engineering|
|Publication status||Published - Aug 2017|
Bibliographical noteFunding Information:
Financial support was given by CONACyT, Mexico (granted for Jorge Isaac Martínez Corona with CVU 166466 and for Ruben Rogelio Cisneros Garza with CVU 406592, Felipe Robledo-Padilla CVU 173853) and Environmental Bioprocesses Group, Emerging Technologies and Molecular Nutrition, Centro de Biotecnología-FEMSA, Tecnologico de Monterrey.
© 2017 by De Gruyter.
Copyright 2018 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)