Simulation studies of the characteristics of a cryogenic distillation column for hydrogen isotope separation

•A dynamic model of a hydrogen isotope distillation column has been presented.•Packed distillation tower has been simulated as equivalent tray tower using HETP.•Dynamic composition profiles for the isotopic species have been derived.•Effect of various parameters on column's separation performance has been studied.•Column hydraulic behaviour and effect of tritium's decay heat have been evaluated.

Cryogenic distillation is a very widely applied technique for separating the components of a mixture of hydrogen isotopes, which may contain up to six isotopic species. This work presents a simple dynamic model for evaluating the major performance characteristics of a cryogenic distillation column for hydrogen isotope separation. Liquid hold up, pressure drop and flooding point have been predicted for the tower using known packing characteristics and fluid properties. The column has been modelled as an equivalent tray tower using a known value of the height equivalent to theoretical plate (HETP) and its dynamic behaviour and separation performance under various conditions have been predicted. The effect of parameters like temperature, reflux ratio, feed point location and feed composition on the final isotopic contents of top and bottom products at steady state has also been studied. Consequences of neglecting the decay heat of tritium in distillation calculations have also been evaluated. This model is intended for preliminary column design work using data from literature, without the need for prior experimental activity.