(78c) Design of an Automated Control System for a Continuous Distillation Column and Its Implementation into the Unit Operations Laboratory Experimental Program

A research program is described that transforms a manually operated continuous-flow, pilot-scale distillation column into a fully automated system based upon a process logic controller (PLC) with a customized operator interface. The new system provides an advanced platform to investigate both steady-state and process dynamics of either binary or multicomponent distillation to support both student training and research in advanced separation processes. The automation package is based upon a Siemens series 505 PLC with a Wonderware Intouchâ„¢ human machine interface (HMI). Various field instruments used to measure local pressures, temperatures, flow rates and specie concentrations are connected to the PLC using a special-purpose hardware interface. The process and instrumentation diagram, instrumentation, operator interface and experimental protocols are described along with process safety aspects. The HMI is configured so the user can operate the system using either manual or automatic modes. The user can define a timed-sequence for the process input variables from which the corresponding system output responses can be displayed in real-time. An advanced experimental program developed for the undergraduate level Unit Operations Laboratory courses based on the automated system is described. This experimental program will enhance student educational outcomes in the core Chemical Engineering curriculum areas of separations, mass and heat transfer, phase equilibria, and process control.