Minimum Reflux of Complex Distillation Columns: Adiabatic Flash Method on Enthalpy-Composition Diagram

摘要

In this work, the minimum reflux of Petyluk system for ideal ternary mixtures is considered. The minimum reflux is calculated with adiabatic flash solutions and the Boundary Value Method (Doherty and Malone, 2001). In this case, the roots of adiabatic flash of specified products (Pre-fractionator and later the Main Colum of Petlyuk) are used to determine when the enriching and stripping sections coincides. Aspen Plus steady state simulation shows that this methodology estimates the minimum reflux values. Pentane-Hexane-Heptane mixture (ideal thermodynamically system) was considered. This methodology can estimate the minimum reflux ratio for Petlyuk columns for ternary ideal mixtures, but it can be used to conventional columns. With the minimum reflux calculated, a stage-by-stage method solution can be used to estimate the number of stages, feed stage and interconnecting stages of Petlyuk column using the appropriate reflux ratio. Because this methodology could use rigorous thermodynamic models (equation of state or activity models), potential applications of non-ideal mixtures could be considered in the design of Petlyuk or other TCDS.