Authors
1 Chemical Engineering Department, University of Technology /Baghdad
2 Chemical Engineering Department, University of Technology/Baghdad
Abstract
The present work is designed to study the parameters interaction of sterilization
processes in batch bioreactors (fermentors of volume 120 liter with medium of 56784 kg).
he parameters include the effects of sterilization temperatures (117-126
o
C), time of
heating, time of holding, and time of cooling on removal of all organisms, and degradation
degree of medium. Direct steam was used for heating at different temperatures ranged
from 120
o
C to 180
o
C. The B.Stearothermophilus was selected as the present contaminants.
Another bioreactor of volume (56828) liter was studied at 121
o
C for the same contaminant
and compared with actual data.
This study is achieved by designed procedure and simulation program useful for
the optimization of batch sterilization cycle in large-scale fermentors. The method of
optimization used is Genetic Algorithm (GAs) which uses probability to find the optimum
condition for the sterilization cycle and to find Del factor; which is the reduction value of
initial to final number of microorganisms, and then evaluate the cost which depend on
amount of steam consumed in the sterilization processes
Graphical relations was indicated that as fermentor size increase, the time of
heating also increase. For low temperature the time of holding was increased and for high
temperature the time of holding was decreased. Also these relations were investigated the
best conditions between holding time and Del factor for degradation at different
temperatures.
Keywords
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