Optimal Synthesis of Liquid-Liquid Extraction Networks

In this work, we present a methodology for the global optimization of liquid-liquid extraction networks, through the Infinite DimensionAl State-space (IDEAS) approach. The IDEAS conceptual framework gives rise to an Infinite linear program (ILP). The solution of a series of finite dimensional linear programs is the values that converge to the infinite program's infimum. The proposed optimal design methodology will be demonstrated in a case study. A detailed liquid-liquid extraction model is used in the IDEAS context. It employs a LLE thermodynamic model based on modified Raoult's law, with an NRTL equation consisting of binary interaction parameters to model the non-ideality of the liquid phase. Despite the complex and the nonlinear nature of the underlying thermodynamic model, the IDEAS approach yields nevertheless a linear program formulation of the global minimum capital cost. ighted linear combination of the liquid hold-up and plate area.