Debottlenecking the Retrofitted Thermally Coupled Distillation Sequence

Abstract

The thermally coupled distillation sequence (TCDS) has attracted increasing interest in a range of chemical processes because of its potential energy and capital cost savings in multicomponent separations. In addition, the TCDS has attracted particular attention in retrofit projects because of its lower energy requirements compared to the existing conventional column sequence, easy design, and small modification. This, however, can create a bottleneck in the column. The main aim of this study was to identify bottlenecks in a retrofitted TCDS systematically using a hydraulic performance indicator and fractional utilization of area (FUA), and to propose a novel strategy for the use of a side reboiler or a side condenser for debottlenecking of the column. A practical method using the response surface methodology (RSM) is proposed for TCDS design and optimization. The optimum TCDS structure can be observed in a practical manner while minimizing the simulation runs. The use of a side reboiler or a side condens...