**5. Conclusion**

The analyses of two closed loops at a distillation process were presented at this chapter. The design specification presented at the references was attended through the use of an exhaustive search algorithm to obtain the best response according to the performance indices Integral Absolute Error (IAE). MATLAB code used to apply this algorithm is effective and generated a better response than that presented at references. Using MATLAB and SIMULINK it was designed a Smith Predictor algorithm and an enhanced control system was obtained. The MATLAB toolboxes used to analyse the control system was very useful to enhance the control system design. The digital representation of the control system was calculated with digital control systems commands.
