Ekstraktiotislausta

Ekstraktiotislausta, sometimes referred to as extractive distillation in English, is a chemical engineering process used to separate components of a mixture that have very close boiling points or form azeotropes. This technique combines distillation and liquid-liquid extraction into a single unit operation.

The core principle of ekstraktiotislausta involves introducing a third component, known as an entrainer or solvent, into the distillation column. This entrainer is carefully chosen to alter the relative volatilities of the components to be separated. By selectively interacting with one or more of the original components, the entrainer changes their vapor pressures and thus their boiling behavior within the column.

In a typical setup, the feed mixture is introduced into the middle section of the distillation column. The entrainer is usually fed near the top. As the mixture ascends and descends, the entrainer preferentially associates with one of the components, effectively "extracting" it into a different phase or significantly reducing its volatility relative to the other components. This allows for a cleaner separation.

The entrainer is then separated from the desired product in a subsequent distillation step, and it is often recycled back into the process to improve efficiency and reduce costs. Ekstraktiotislausta is particularly useful in industries like petrochemicals and fine chemicals where precise separation of difficult-to-distill mixtures is crucial. Common applications include the separation of aromatic hydrocarbons from aliphatic hydrocarbons and the breaking of azeotropes. The effectiveness of the process relies heavily on the appropriate selection of the entrainer and the operating conditions of the distillation column.