(32a) Quantifying the Effect of Stripping Factor on Distillation Efficiency Using Cyclopentanol/Cyclohexanol Test System

The optimal design of distillation columns requires reliable estimates of column efficiencies. Several models and correlations have been developed over the years to predict column efficiencies. However, these models may not be truly representative of actual efficiencies observed in the plant as most experimental data used to develop these models were obtained from distillation tests under total reflux conditions. Since commercial-scale distillation columns operate under non-total reflux, there is a need to obtain accurate experimental data on efficiencies under non-total reflux conditions. Such data will be helpful in developing reliable efficiency models based on both total reflux and non-total reflux conditions.

The stripping factor is an important variable that comes into the picture in the non-total reflux operation of a distillation column. The stripping factor is defined as the ratio of the slope of the equilibrium curve to that of the operating curve or line. In total reflux mode, the stripping factor is close to 1.0; however, in the actual commercial operation, the stripping factor deviates from unity. This study aims to fill the gap in the existing literature and provide new experimental data based on the non-total reflux mode of operation. Therefore, in this study, we present recent results obtained from an Oldershaw column under non-total reflux conditions for a highly viscous cyclopentanol/cyclohexanol test system. An Oldershaw column capable of operating in both total reflux and non-total reflux modes was used to measure point efficiency data over a range of conditions. The experimental results were also compared with the L/V ratios and the product concentrations obtained from column simulation in Aspen Plus®, both of which showed close agreement. Important findings from this ongoing study will be discussed