No abstract

Abstrucf -In order to get the highest concentration of citric acid in the fermentation , a model of the multiobjective fuzzy process control is. put forward in this paper. And aslo a series of rules determining the values of the control variables in this model, based on the records of citric acid fermentation , the mathematical models from the scientists on biotechnology and the experience from the engineers on the fermentation control, is set up and refined stepwise. To examine this model and these rules, experiments were conducted on a 1.5" fermenter. The results show that the citric acid concentration reaches 10.39%with the initial glucose concentration 11.30%. in comparison with the citric acid concentration 11.4% with the initis! glucose concentration 14.2% in normal control on a 100 m3 fermenter .The fermentation time is shortened from 70 hours (normal control ) to 63 hours . The residual glucose concentration hits the lowest level 1.36% in this company.