Thermally Coupled Side-Column Configurations Enabling Distillation Boundary Crossing. 1. An Overview and a Solving Procedure

In this paper, the thermally coupled side-rectifier and side-stripper configurations are studied in the separation of component sets with a curved distillation boundary. A solving procedure is introduced that can be used in the determination of the minimum total energy consumption for the studied complex separation structures. The results show that thermally coupled side-column configurations enable distillation boundary crossing with high product now purities. In fact, the achievable purities are higher than is possible with conventional column sequences. It is also noted that in some methanol/ethanol/water separations the energy consumption of the thermally coupled side-stripper configuration may partly decrease with increasing methanol distillate purity.