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Difference between revisions of "Distillation"
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|Name= Distillation}} | |Name= Distillation}} | ||
<onlyinclude>'''Distillation''' is the process of separating | <onlyinclude>'''Distillation''' is the process of separating components or substances from a liquid mixture by using selective boiling and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components in the mixture. In industrial applications, distillation is a physical separation process, not a chemical reaction. The application of distillation covers various options, for example purification of alcohol, desalination, crude oil refining, or making liquefied gases from air.</onlyinclude> | ||
==Feedstock== | ==Feedstock== | ||
=== Origin and composition === | === Origin and composition === | ||
Since distillation is limited for the use of liquid mixtures, the feedstock needs to be in liquid form. Examples in the field of [[biowaste]] here are fermented biowaste resources (as bioethanol) or bio oils. <ref name=":0">{{Cite journal|title=Techno-economic assessment of hybrid extraction and distillation processes for furfural production from lignocellulosic biomass|year=2017-12|author=Le Cao Nhien, Nguyen Van Duc Long, Sangyong Kim, Moonyong Lee|journal=Biotechnology for Biofuels|volume=10|issue=1|page=81|doi=10.1186/s13068-017-0767-3}}</ref><ref name=":1">{{Cite journal|title=Renewable diesel blendstocks produced by hydrothermal liquefaction of wet biowaste|year=2018-11|author=Wan-Ting Chen, Yuanhui Zhang, Timothy H. Lee, Zhenwei Wu, Buchun Si, Chia-Fon F. Lee|journal=Nature Sustainability|volume=1|issue=11|page=702–710|doi=10.1038/s41893-018-0172-3}}</ref> | |||
=== Pre-treatment === | |||
For a distillation no specific pre-treatment is needed since it is used to separate different fraction within a process chain. To gain a liquid product from bio waste resources, [[fermentation]] or [[hydrothermal processing]] (hydrothermal liquefaction) are possible pre-treatment technologies. Sometimes there are combination options with other technologies, such as [[extraction]] or [[esterification]], for higher efficiencies.<ref name=":0" /><ref name=":1" /> | |||
With distillation, it is not possible to completely purify a mixture of components, as this would require each component in the mixture to have a zero partial pressure. If ultra-pure products are the goal, then further chemical separation must be applied. | |||
==Process and technologies== | ==Process and technologies== | ||
[[File:Colonne distillazione.jpg|thumb | [[File:Total Reflux.png|thumb|219x219px|Distillation column]] | ||
Distillation exploits differences in ''relative volatilities'' of the feed mixture components. In a distillation column a feed stream enters in the middle of the column and two streams leave, one at the top and one at the bottom. Components with ''lower boiling points'' are concentrated in the stream leaving the top while components with ''higher boiling points'' are concentrated in the stream leaving the bottom. | |||
Separation is achieved by controlling the column temperature and pressure profiles to take advantage of differences in the relative volatility of the mixture components and therefore tendency to change phase. The lighter, lower boiling point components evaporate to the top of the column and the heavier, higher boiling point components condense to the bottom of the column. | |||
This application is often referred to as ''rectification'', which is a successive distillation. A simple distillation is not often used for industrial applications. The main advantages of rectification are that the system can be operated continuously and that the separation effect is many times greater than that of a simple distillation. The reason for this lies in the several countercurrent contacts of the vapour with the liquid. Therefore, rectification is preferred to sequential single distillations.[[File:Colonne distillazione.jpg|thumb|Typical industrial distillation towers|237x237px]] | |||
A plant that performs distillation is called a ''distillery''. The apparatus used to perform distillation is called a ''still''. | |||
Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids). Dry distillation may involve chemical changes such as destructive distillation or cracking and is not | ==== Dry distillation ==== | ||
Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids). Dry distillation may involve chemical changes such as destructive distillation or cracking and is not further addressed under this article. | |||
==Products== | ==Products== | ||
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==References== | ==References== | ||
* [[:en:distillation|Distilation]] in Wikipedia | * [[:en:distillation|Distilation]] in Wikipedia | ||
*[https://neutrium.net/unit-operations/distillation-fundamentals/ Distilliation Fundamentals] at Neutrium | |||
[[Category:Pre-processing]] | [[Category:Pre-processing]] | ||
[[Category:Post-processing]] | [[Category:Post-processing]] | ||
[[Category:Technologies]] | [[Category:Technologies]] | ||