MULTICOMPONENT DISTILLATION CALCULATIONS USING SIMPLIFIED TECHNIQUES

Short-cut techniques for simulation of simple distillation columns, and complex columns incorporating sidedraw products and interstage heat exchange are presented. The advantageous features of these techniques over rigorous tray-by-tray calculations are the short computer execution times and low core storage requirements. These features, in conjunction with the high accuracy attained when compared to rigorous solution techniques make the presented models ideal for simulation of distillation columns on small real-time computers, where they can be used as part of online optimization and closed-loop control systems. The models are also particularly useful in generating overall and component mass balances as a starting guess for more rigorous tray-by-tray calculations. The robustness of the models is such that they converge to a mass balanced solution in excess of 99.9% of the time.