Premium
Enhancement of the overall volumetric oxygen transfer coefficient in a stirred tank bioreactor using ethanol
Author(s) -
Bi Yonghong,
Hill Gordon A.,
Sumner Robert J.
Publication year - 2001
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450790322
Subject(s) - impeller , distilled water , mass transfer coefficient , mass transfer , bioreactor , bubble , oxygen , ethanol , materials science , chromatography , chemistry , continuous stirred tank reactor , analytical chemistry (journal) , thermodynamics , mechanics , physics , organic chemistry
Ethanol was observed to improve the oxygen mass transfer rate into a well‐mixed bioreactor. The effects of impeller speed and ethanol concentration on the oxygen transfer from air to the water phase and on the average bubble diameter in a stirred tank bioreactor are reported and modelled. The results show that the oxygen mass transfer coefficient ( kLa ) increases from 0.002 to 0.017 s −1 (for distilled water) due to the increase of impeller speed from 135 to 600 rpm. With increasing ethanol concentration from 0 to 8 g/L, the oxygen mass transfer coefficients increase from 0.015 to 0.049 s −1 and from 0.017 to 0.076 s −1 , for impeller speeds of 450 and 600 rpm, respectively. The average bubble diameter decreased from 7.0 mm to 1.7 mm in pure distilled water as the impeller speed was increased from 135 to 600 rpm. When ethanol was present in the aqueous phase, the bubble diameter fell from 6.0 mm to 0.6 mm as the impeller speed was similarly increased.