Flexible Batch Process and Plant Design Using Mixed-Logic Dynamic Optimization: Single-Product Plants

Abstract

Batch manufacturing plants require the frequent adaptation of production facilities to incorporate internal and external uncertainties. The introduction of flexibility in the design of general-purpose plants represents a cornerstone for the design and retrofit of batch processes along the plant's lifecycle. Moreover, the integration of batch process development decisions during the plant design also contributes to handle uncertainty. This paper presents a novel optimization-based approach for the flexible design of batch plants by integrating process synthesis and plant allocation decisions, such as feedforward control trajectories of processing conditions or the selection of operating modes and equipment items. To do so, a modeling strategy based on Mixed-Logic Dynamic Optimization and two-stage stochastic formulation is used to maximize the expected profit taking into account several uncertain scenarios. Moreover, a heuristic algorithm is proposed to solve the resulting problem that is characterized by a great complexity, consisting of an iterative procedure with embedded deterministic solutions of the integrated problem. The proposed approach is illustrated through the design of a single-product batch plant to carry out a competitive reaction process.

A modeling strategy for integrated batch process development based on mixed-logic dynamic optimization

“…However, this similarity does not represent homogeneity in the optimal solution of each subsystem, but adaptability of the model to provide favorable solutions by evaluating the decisions trade-offs. Actually, previous research on flexible plant design [24] has proved the enhancement of batch plant flexibility by combining process synthesis decisions, like dynamic control profiles, with plant allocation decisions, like batch sizing.…”

“…However, divide and conquer strategies jeopardize the efficiency of the resulting process. On the one hand, the sequential solution of batch process development involves losing a significant part of the interaction among the degrees of freedom, thus restricting the system trade-off evaluation according to global industrialscale objectives [24]. On the other hand, the direct implementation of fixed recipes in existing equipment may force its operation in extreme and even infeasible conditions [25].…”