Effects of temperature, flow rate, number of stages and a heads column on congener removal in fuel‐ethanol distillation: a simulation study

Abstract BACKGROUND Industrial fuel‐ethanol units must remove trace volatile congeners (acetaldehyde, ethyl acetate, carbon dioxide) to meet quality requirements. In Brazilian systems, a small heads column (“Column D”) is often placed above the stripper. This study evaluated the effect of Column D in removing congeners by comparing it to other systems that do not have it. RESULTS Steady‐state simulations of a beer‐ethanol stripper coupled to a rectifier were performed in a commercial process simulator. In the stripper alone, the configuration with Column D removed 42.39% acetaldehyde and 51.72% ethyl acetate, whereas simplified arrangements without Column D removed only 5.31–18.91% acetaldehyde and 1.72–11.62% ethyl acetate. After rectification, however, total acetaldehyde removals became similar for all feeds (91.50% compared to 88.14% and 86.06%), and ethyl acetate removals also approached each other (55.63% compared to 58.97% and 41.06%), showing that the rectifier can recover most of the separation initially provided by Column D. CONCLUSION The results indicate that while Column D can improve removal of congeners such as acetaldehyde and ethyl acetate in stand‐alone stripper simulations, its benefits become less pronounced once the rectifier column is considered. Analysis further reveals that feed composition is an important factor for ethyl acetate removal: at lower ethanol concentrations, ethyl acetate can be more effectively stripped due to its higher relative volatility. These findings suggest that careful adjustments of process parameters can match or surpass the separation efficiency given by an additional column, potentially reducing both operational costs and ethanol losses. © 2026 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).