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其它类型的蒸馏

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核心提示:In rotary evaporation a vacuum distillation apparatus is used to remove bulk solvents from a sample. Typically the vacuum is generated by a water aspirator or a membrane pump. In a kugelrohr a short path distillation apparatus is typically used (gen


      In rotary evaporation a vacuum distillation apparatus is used to remove bulk solvents from a sample. Typically the vacuum is generated by a water aspirator or a membrane pump.

      In a kugelrohr a short path distillation apparatus is typically used (generally in combination with a (high) vacuum) to distill high boiling (> 300 °C) compounds. The apparatus consists of an oven in which the compound to be distilled is placed, a receiving portion which is outside of the oven, and a means of rotating the sample. The vacuum is normally generated by using a high vacuum pump.

      The process of reactive distillation involves using the reaction vessel as the still. In this process, the product is usually significantly lower-boiling than its reactants. As the product is formed from the reactants, it is vaporized and removed from the reaction mixture. This technique is an example of a continuous vs. a batch process; advantages include less downtime to charge the reaction vessel with starting material, and less workup.

      Destructive distillation involves the strong heating of solids (often organic material) in the absence of oxygen (to prevent combustion) to evaporate various high-boiling liquids, as well as thermolysis products. The gases evolved are cooled and condensed as in normal distillation. The destructive distillation of wood to give methanol is the root of its common name - wood alcohol.

      Pervaporation is a method for the separation of mixtures of liquids by partial vaporization through a non-porous membrane.

      Dry distillation, despite its name, is not truly distillation, but rather a chemical reaction known as pyrolysis in which solid substances are heated in a strongly reducing atmosphere and any volatile fractions are collected.

      Extractive distillation is defined as distillation in the presence of a miscible, high boiling, relatively non-volatile component, the solvent, that forms no azeotrope with the other components in the mixture.

      Flash evaporation (or partial evaporation) is the partial vaporization that occurs when a saturated liquid stream undergoes a reduction in pressure by passing through a throttling valve or other throttling device. This process is one of the simplest unit operations.

      Freeze distillation is an analogous method of purification using freezing instead of evaporation. It is not truly distillation, and does not produce products equivalent to distillation. This process is used in the production of ice beer and ice wine to increase ethanol and sugar content, respectively.

      Codistillation is distillation which is performed on mixtures in which the two compounds are not miscible.

      在旋转蒸发中,使用真空蒸馏设备将大量的溶剂从样品内除去。真空由水抽子或隔膜泵产生。

      在kugelrohr蒸馏中,通常使用短程蒸馏设备(一般与高真空结合),以蒸馏高沸点(> 300 °C)的化合物。该设备包括一个放置被蒸馏的化合物的炉子,一个处于炉子外的接收部分以及样品旋转设备。一般使用高真空泵来产生真空。

      反应蒸馏的过程涉及到用作反应釜的蒸馏釜。在这一过程中,反应产物的沸点比反应物沸点低得多。产物由反应物形成的同时,就被汽化并从反应混合物中去除。该技术是连续式蒸馏与间歇式蒸馏相对的例子。优点包括:给反应釜内添加原料的停工时间少;工作量小。

      分解蒸馏涉及到对固体物质(常为有机物)在缺氧条件下的强烈加热(以防燃烧),以蒸馏去各种高沸液体及热分解产物。与常规蒸馏一样,分解蒸馏中所产生的气体被冷却并冷凝下来。产出甲醇的木材分解蒸馏是甲醇普通名称(木醇)的根源。

      渗透蒸发是一种通过非多孔膜对液体混合物进行部分汽化的分离方法。

      干馏,尽管名称如此,但实际上不是蒸馏,而是一种广为人知的热分解反应,反应中,固体物质在强烈的减压状态下受热,任何挥发性组分都被收集下来。

      淬取蒸馏的定义为:有易混合的、高沸的、相对难挥发的组分和溶剂存在下的蒸馏,且这些组分和溶剂不与混合物中的其它组分形成恒沸物。

      快速蒸发(或部分蒸发)是让饱和液流通过节流阀或其它节流装置,使其经历压力减小而发生的部分汽化。


      冷冻蒸馏是一种用冷冻代替汽化的类似的提纯方法。它其实不是蒸馏,也不产生与蒸馏等同的产物。此法用于冰啤酒和冰葡萄酒的生产中,以分别增加乙醇和糖的含量

      共馏是对由不易混合的两种化合物组成的混合物进行的蒸馏。

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      关键词: 类型 蒸馏
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