This paper investigates some aspects of the parastillation process, which employs a unique distillation column. A laboratory scale apparatus was used to study the parastillation column. Experiments were carried out under total and partial reflux conditions, using an ethanol-water system. Experiments were conducted to analyze the influence of the vapour flow rate and reboiler initial ethanol concentration on the hydrodynamic conditions. Limiting operating conditions were defined. Murphree separation efficiencies were calculated and discussed.