Batch Distillation Simulation

The design of a batch distillation column requires a fundamental understanding of each of the parameters that influence column performance. Often times, a desired distillate composition is known, and the design is required to meet these needs. Various other parameters can influence the design of the column including the bottom's composition, the heat input, column efficiency, and the reflux ratio. The purpose of this work is to design a working model to simulate a batch distillation experiment with the intent of producing a constant distillate composition, and the ability to vary other parameters to get a sense of an optimal design.

The model was developed using a combination of Excel and Visual Basic, which work together to simulate the performance of a given column. The implications of a changing bottoms composition require a varying reflux ratio to produce the desired distillate composition. The model acts to vary this ratio throughout the simulation when given certain input parameters. The use of this model can then be used to compare the interactions between the heat input, required time, and the number of trays to determine the most economical design to be employed.

With the simulation complete, the data was compared to experimental results to determine the accuracy of the model. The comparison of the results proved the concept of the simulation, and provided a very close approximation of the required reflux ratio and time required for the experiment. Various factors such as heat loss and column efficiency can be attributed to the error present in the model. The simulation can be used in providing approximate experimental results, and as an initial tool in the design of a new column or existing batch process.