Modeling and Simulation of a Distillation Column using MATLAB

In this work, the modeling and simulation of a distillation column has been done. The distillation column has been simulated by varying parameters such as the inlet feed composition, relative volatility of the feed and reflux ratio of the column to study the effects of these parameters on the product composition. This has been done using the MATLAB software. MATLAB is a high level language and can be used to model energy consumption and for developing control algorithms. Effects of various parameters with respect to the independent variable have been obtained. Graphs have been plotted to show the effects of each parameter, and how variation in them might affect product quality. Graphs have been analyzed and the results obtained have been interpreted. The distillate concentration obtained decreases as the feed condition increases from superheated vapour (q<0) to feed below bubble point (q>1). So, in order to achieve higher distillate concentrations the vapour fraction of the feed must be increased and liquid fraction must be decreased. This can be done by increasing the amount of preheat to the feed before it enters the distillation column. As the reflux ratio of the distillation column increases, the distillate concentration also increases. Thus, efficiency of separation of a distillation column can be increased if it is operated at higher reflux ratio. Moreover, as the relative volatility of the feed increases then the distillate concentration increases even at constant reflux ratio. Thus, in order to achieve higher separation efficiencies, efforts must be made to increase the relative volatility of the feed by adding entrainers (salt). Increasing the distillate concentration from a distillation column would ensure higher product purity and minimize the requirement of distillation trays. This would reduce the overall cost of the plant and increase the net revenue earned.