MINLP Optimization of the Hybrid Separation Process Distillation/Melt Crystallization

Abstract

MINLP Optimization of the Hybrid Separation Process Distillation/Melt CrystallizationThe hybrid separation process distillation/melt crystallization offers a cost wise attractive alternative compared to conventional distillation processes. In this work, the systematic and cost optimal design of this combination process is considered.The focus is on the optimal choice of operating and structural degrees of freedom.

Design of hybrid distillation/melt crystallisation processes for separation of close boiling mixtures

“…These two variants have been compared in the literature, wherein it was demonstrated that it is always preferable to place the crystallisation before the distillation [27,28]. The performance of the crystallisation units is similar in both variants; the advantages of variant V include the lower energy demand and lower investment costs in the column due to the reduction of the column feed [27,28]. Hence, it is sufficient to consider only variants I and V in the evaluation of alternatives using rigorous models in the next step.…”

“…The process variants for the separation of the binary system, which are used in the initial search space, are provided in Fig. 5 [27]. Variant I is the stand-alone distillation.…”

Design of Dividing‐Wall Columns by Mixed‐Integer Nonlinear Programming Optimization

“…The mGBD algorithm with the fix-and-discard-strategy was successfully applied in heterogeneous distillation processes [11]. An older version that differs in the formulation of Lagrangian function was used for the design of hybrid separation processes [10,40,41]. Although the quality of the optimum was confirmed by parameter studies and different initial values of the optimization variables, global optimality cannot be proven in a strict mathematical sense.…”