Study of the optimization condition of batch sterilization using genetic algorithm

Abstract EN

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 ºC), 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 from120 ºC to 180 ºC.

The B.

Stearothermophilus was selected as the present contaminants.

Another bioreactor of volume (56828) liter was studied at 121 ºC 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.