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Modeling the influence of slurry concentration on Saccharomyces cerevisiae cake porosity and resistance during microfiltration
Author(s) -
Mota Manuel,
Flickinger Michael C.
Publication year - 2012
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.1636
Subject(s) - microfiltration , slurry , yeast , filtration (mathematics) , porosity , chemistry , suspension (topology) , chromatography , membrane , cross flow filtration , materials science , composite material , biochemistry , mathematics , statistics , homotopy , pure mathematics
Filtration of an isotonic suspension of baker's yeast through a 0.45‐μm membrane was studied at two different pressures, 40 and 80 kPa, for yeast concentrations ranging from 0.14 to 51 kg/m 3 (dry weight). For a yeast volume fraction above 0.06 (∼21.8 kg/m 3 ), the porosity of the yeast cake is less dependent on the suspension concentration. For highly diluted suspensions, the specific cake resistance approaches a minimum that depends on the filtration pressure. Correlation functions of cake porosity and specific cake resistance were obtained for the concentration range investigated showing that the Kozeny–Carman coefficient increases when the applied pressure increases. Both filtration pressure and slurry concentration can be process controlled. In the range of moderate yeast concentration, the filtrate flux may be increased by manipulating the filtration pressure and the slurry concentration, thereby improving the overall process efficiency. The complex behavior of yeast cakes at high slurry concentration can be described by a conventional model as long as part of yeast cells are assumed to form aggregates, which behave as single bigger particles. The aggregation effect may be accounted for using a binary mixture model. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012