Reducing CO2 emissions of internally heat-integrated distillation columns for separation of close boiling mixtures

A model developed originally for crude oil distillation units has been applied to a standalone internally heat integrated distillation column (HIDiC) to evaluate emissions levels and to generate design options for direct carbon dioxide emissions reduction. Simulations indicate that for propylene–propane separation, an ideal (no reboiler) HIDiC enables a reduction in emissions of 83% and of 36%, compared to conventional and heat pump alternatives, respectively. Integrating a turbine to drive the compressor, in conjunction with a suitable fuel is the key to the minimization of the emissions associated with the operation of a HIDiC. Importantly, while substantial emission reductions are achieved, the process economics are improved.