EFFECT OF SUGAR CONSUMPTION ON ETHANOL FERMENTATION IN A TOWER FERMENTER PACKED WITH SELF-AGGREGATING YEAST - MATHEMATICAL-MODELING AND BEDHEIGHT PREDICTION
Cs. Chen et al., EFFECT OF SUGAR CONSUMPTION ON ETHANOL FERMENTATION IN A TOWER FERMENTER PACKED WITH SELF-AGGREGATING YEAST - MATHEMATICAL-MODELING AND BEDHEIGHT PREDICTION, Applied biochemistry and biotechnology, 39, 1993, pp. 491-508
A strain of self-aggregating Saccharomyces uvarum was cultivated in a
6-L tower fermentor for continuous ethanol fermentation. Large aggrega
tes (2-3 mm) were formed and packed in the column. The height of this
packed region depends on the sugar concentration. As sugar concentrati
ons were reduced to below a critical value, most of the large aggregat
es disintegrated into smaller aggregates (0.1-0.2 mm). Above the packe
d bed region, small aggregates and small amount of large aggregates we
re fluidized and formed a well mixed region by the liquid medium and t
he produced carbon dioxide. A mathematical model of a plug flow with c
onsideration of axial dispersion and a Continuous Stirred Tank Reactor
(CSTR) in series is proposed to describe such fermentor. The concentr
ation profile of sugar can be simulated by this model. The height of t
he packed bed region can then be estimated based on the predetermined
critical sugar concentration. Final ethanol concentration and the prod
uctivity of such fermentor can also be predicted.