1,3-丙二醇间歇发酵中的时滞最优控制

Delay optimal control of 1,3-propanediol batch fermentation

在甘油通过间歇发酵转化为1,3-丙二醇的生产过程中,微生物和甘油的初始浓度会影响产物的生产效率。为了最大化1,3-丙二醇生产效率,提出了一个含有约束的时滞最优控制模型。对于该时滞最优控制问题,首先,通过时域变换将其转化为一个等价的最优控制问题;然后,使用罚函数方法来处理其中的约束条件;最后,构造了一种模拟退火与遗传混合算法对其进行求解。数值结果表明,终端时刻1,3-丙二醇的生产效率比已有结果提高了21.12%。

In the batch process of glycerol bioconversion to 1,3-propanediol,the initial biomass and glycerol concentration will affect the productivity of 1,3-propanediol.This paper proposes a constrained delay optimal control model to maximize the productivi-ty of 1,3-propanediol.For this problem,the time-scaling transformation is applied to convert it to an optimal control problem with fixed terminal time.Then,the penalty method is used to deal with the constraints in the optimal control problem.Finally,a hybrid algorithm of simulated annealing and genetic algorithm is developed to solve the resulting problem.Numerical results indicate that the productivity of 1,3-propanediol increases by 21.12% compared with the previous result.