Very few unbiased publications have appeared in the literature comparing control effectiveness using MPC versus a well-designed conventional control system. Most of the MPC applications reported have considered fairly simple processes with a small number of manipulated variables. There are no published reports that discuss the application of MPC to an entire complex chemical plant, with one notable exception. It is found that a good control structure provides effective control, independent of any particular controller algorithm, while a poor one cannot be greatly improved with any algorithm (MPC or PID controllers). In this paper, a Gas Plant is simulated in a rather realistic environment by HYSYS, and the obtained data is in connection with MATLAB (R). To have more realistic simulations, the model of process is simulated in HYSYS (R), and the data is transferred (real-time) to MATLAB (R) for identification and control purposes.