Modeling of a distillation column using bond graphs

Abstract

Modeling and simulating distillation columns is not a new enterprise. All of the models described in the literature either contain algebraic loops or simplifying assumptions that render the model ill-equipped for dynamic simulations. The structure and the equations that represent a trayed distillation column are explored using bond graphs. Bond graphs model the power flow in a system, an inherently instructive way to view complex systems. The power of bond graphs is evident by providing a clear, graphical representation of a distillation column that systematically organizes the equations and possible approximations. The model of a distillation column is explored in general and then by using a specific model developed by Steven Gallun. Results of this study reveal several ways of eliminating the algebraic loops and producing a dynamic model. The bond graph model can be expanded by introducing other elements including chemical reactions and thermal interaction with other columns.