Spinning band distillation is a technique used to separate liquid mixtures which are similar in boiling points. When liquids with similar boiling points are
distilled
Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the hea ...
, the vapors are mixtures, and not pure compounds.
Fractionating column
A fractionating column or fractional column is an essential item used in the distillation of liquid mixtures to separate the mixture into its component parts, or fractions, based on the differences in volatilities. Fractionating columns are used in ...
s help separate the mixture by allowing the mixed vapors to cool, condense, and vaporize again in accordance with
Raoult's law. With each condensation-vaporization cycles, the vapors are enriched in a certain component. A larger surface area allows more cycles, improving separation.
Spinning band distillation takes this concept one step further by using a spinning helical band made of an inert material such as metal or
Teflon
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemo ...
to push the rising vapors and descending condensate to the sides of the column, coming into close contact with each other. This speeds up equilibration and provides for a greater number of condensation-vaporization cycles.
Applications
Spinning band distillation may sometimes be used to recycle waste solvents which contain different solvents, and other
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
s.
See also
*
Spinning cone Spinning cone columns are used in a form of low temperature vacuum steam distillation to gently extract volatile chemicals from liquid foodstuffs while minimising the effect on the taste of the product. For instance, the columns can be used to remov ...
* The French Wikipedia webpage fo
Spinning Band Distillationcontains more information than the English language version (here) and a few images that are missing from this webpage.
References
* B/R Instrument Corporation
accessed 27 Oct, 2006.
* B/R Instrument Corporation
accessed 27 Oct 2006.
* Marshall Space Flight Center
Accessed 27 Oct 2006.
{{Distillation
Distillation
Separation processes
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