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A new approach for k L a determination by gassing‐out method in pneumatic bioreactors
Author(s) -
Cerri Marcel Otavio,
Nordi Esperança Mateus,
Colli Badino Alberto,
Perencin de Arruda Ribeiro Marcelo
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4937
Subject(s) - bioreactor , airlift , sensitivity (control systems) , electrode , analytical chemistry (journal) , chemistry , process dynamics , transient (computer programming) , biological system , process (computing) , process engineering , mechanics , computer science , materials science , chromatography , physics , electronic engineering , engineering , organic chemistry , biology , operating system
BACKGROUND Determination of the volumetric oxygen transfer coefficient ( k L a ) is very important for bioreactor design and process analysis. Among all the methods available, the gassing‐out technique is one of the simplest and most widely used for this task. However, this method is very sensitive to the probe dynamics (due to delay effects), which can lead to inaccuracy in the k L a determination. This is especially pronounced for airlift bioreactors, where the circulation time affects the initial dynamics of the assay (a transient effect). In the present work, a new method for k L a determination is proposed. RESULTS Values of k L a and the electrode response time ( τ e ) were determined experimentally, employing the traditional gassing‐out method and the method proposed here. The latter was shown to be reliable, easier to apply, and suitable for the simultaneous determination of k L a and electrode sensitivity ( k e = 1/ τ e ), without any need for additional assays. CONCLUSION The new method overcomes the effects of probe delay on k L a determination, making the procedure faster and simpler. © 2016 Society of Chemical Industry