The multiple dividing wall column could separate multi-substance mixtures in a single apparatus and thus reduce investment and energy costs. However, this complex process has so far remained a pipe dream for developers. This could now change: The first plant worldwide has been put into operation and should come as close as possible to the thermodynamic optimum.
Ötzi's contemporaries in the Neolithic Age were already busy coking as soon as they had tamed the fire: Pitch and tar, and later essential oils, were extracted early on using simple distillation vessels made of clay. The ancient Arabs knew how to distil crude oil, which they called naft, and developed the alembic distillation helmet, which allowed the distillation of alcohol. From then on, things went from strength to strength: there was hardly a medieval alchemist's room without a still simmering away. At the latest with the extraction of countless hydrocarbons, separation by evaporation became the basis of value chains in the chemical, pharmaceutical and energy industries.
Distillation is one of the oldest thermal separation processes known to mankind. Today, house-sized columns and crackers form the core of large chemical sites and characterize the image of the industry. And even if, in the course of defossilization, the industry is considering alternative raw materials or electric heating of the apparatus, the fundamental necessity of separating substances thermally remains unchanged.
But "thermal" also means energy-intensive: Around ten percent of the energy generated worldwide is required for distillation processes - there's no changing that. Or is there? A team of researchers led by Professor Thomas Grützner from the Institute of Chemical Engineering in Ulm is working on a small revolution in process engineering: a multiple dividing wall column.
