Design and Operability of an Energy Integrated Distillation Column

Abstract Operability issues are investigated on an energy integrated distillation column. The distillation column separates a nearly binary mixture. The energy integration is achieved using an indirect heat pump between the column condenser and the reboiler. The design aim of the integrated is system to enable operation of the distillation column over its entire operating window, through manipulation of the heatpump variables. An additional aim is to provide the operator with a set of standard distillation column actuators, for controlling the distillation column as a conventional distillation column. This secondary aim is attempted achieved, through selection of the control structure of the heat pump. Both simulation and experimental results illustrate areas within the possible operating window where potential operability problems remain dependent upon the selected control configuration. A very large part of the totally possible operating window may be covered by using just one heat pump control structure. However multivariable control avoids singularity of the multiloop structure.