Mixed‐logic dynamic optimization applied to batch distillation process design

Abstract

An approach for the optimal configuration and sequencing of complex batch-distillation processes is presented. The proposed method is based on formulating a mixed-logic dynamic optimization problem in which a performance index is minimized subject to a disjuncti®e dynamic model and constraints. The disjuncti®e model comprises a gi®en set of equipment modules, such as stacks of trays of different size or feed and product ®essels, a®ailable for the distillation process under consideration along with logical relationships pro®ided by the design context. The optimization based on this model may yield uncon®entional design and operational strategies, and thus impro®e the economic efficiency to a significant extent. The logic-based solution technique proposed in this work offers some fa®orable properties when compared to established mixed-integer dynamic optimization problem solution techniques reported in the literature. The design of a multistage batch-distillation process ser®es as an example to illustrate the proposed modeling and solution method.

Integrated scheduling and dynamic optimization of batch processes using state equipment networks

“…15 Solution methods of MLDOs are discussed along with reformulation techniques for disjunctions and differential algebraic equations (DAEs). To start, we first elucidate how both facets can be tied together in the context of a state equipment network (SEN), which is a flow sheet superstructure we rely on to account for the graphical and also mathematical representation of a process.…”

“…In addition, we show the development of a hybrid discrete-continuous model based on the SEN that eventually gives rise to a mixed-logic dynamic optimization problem (MLDO). 15 Solution methods of MLDOs are discussed along with reformulation techniques for disjunctions and differential algebraic equations (DAEs). Many successful research studies on discrete dynamic systems have been reported from various fields, e.g., integrated design and control, 16 synthesis of rice drying processes 17 and simultaneous scheduling and control optimization in polymer grade transitions.…”

Time‐optimal control of automobile test drives with gear shifts

“…Mixed-integer optimal control problems (MIOCPs) in ordinary differential equations (ODEs) have gained increasing interest over the last years, see references [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. This is probably due to the fact that the underlying processes have a high potential for optimization.…”

Review of Mixed‐Integer Nonlinear and Generalized Disjunctive Programming Methods

“…The dynamic models with mixed discrete and continuous variables are called hybrid systems (which are MIDO problems in general). Start-up and shut-down operations [262], batch systems [263], and grade transitions [258,259] are some of the main applications of optimization of hybrid systems. Several hybrid formulations have been developed and implemented in recent years [264][265][266][267][268][269][270][271].…”