(231d) Reduced Order Modeling of Rate-Based Distillation Columns

This work presents an application of orthogonal collocation to a rigorous, nonequilibrium rate-based packed column. The low order model is constructed with a focus on the feed discontinuity, which is treated as a separate adiabatic flash.

An objective function is defined as the model solution to a combination of degrees of freedom. This definition allows for multiple solutions to a single separation specification to be found. The optimal solution can be subsequently found using an optimization routine. The construction of the objective function ensures that there is always a solution to the design problem.

The resulting low order model has potential use in for the design of distillation trains. If a full-order model is used, numerical difficulties ensue due to the resulting high degree of problem stiffness.