Dividing wall columns: Fundamentals and recent advances

Different distillation sequences for the separation of near-ideal multicomponent mixtures have been proposed in the past. These sequences included both conventional and thermally coupled distillations. Investigations of these sequences based on thermodynamics and steady-state simulations aimed for identifying the economic and energetic favourable configuration. Dividing wall columns have shown to be superior to conventional distillation sequences in certain cases. For this reason dividing wall columns gained increasing application in the last years. More than 90 applications in production scale are known. The advantages are obvious. Depending on the case considered the energy and investment costs are reduced up to 30% compared to conventional technologies. The footprint is significantly smaller. Also advantageous is the higher flexibility of these systems in comparison to conventional column sequences. For temperature-sensitive products the thermal stress is reduced since the product is reboiled only once. Especially for high price products the product quality can be raised by simultaneously increasing the separation yield.