(223b) An Improved Overall Efficiency Correlation Based on Total and Non-Total Reflux Data

The optimal design and performance of a distillation column depend heavily on reliable estimates of the column efficiencies. Different models and correlations have been developed to predict distillation tray efficiencies, but most of these models are based on efficiency data obtained under total reflux conditions. However, the actual operation of a commercial distillation column is based on non-total reflux conditions. Therefore, the current efficiency models may not accurately represent real-world efficiencies. There is a need to develop more reliable models that use data from both total reflux and non-total reflux conditions while accounting for a range of physical properties.

Using the point efficiency data at non-total reflux conditions from our recent study, we evaluated the original O’Connell and Duss & Taylor correlations. Both the correlations underpredicted the point efficiency for the non-total reflux conditions. We modified the Duss & Taylor correlation using both non-total reflux data and total reflux data to evaluate overall column efficiency. We also performed several case studies with the purpose of ultimately developing a modified correlation with the best fit. The validation of the proposed correlation was performed using Chan and Garcia's database, and it was found that the revised correlation predicted overall column efficiency well.