To remove the methylene chloride, one can just have it evaporate by heating. Y do we nid to distill d solvent?

Question

That is, to remove methylene chloride to get the caffeine... y do we need to distill d solvent?

Answer 1

Distillation promotes the recycling of the solvent.
you just cannot waste it by evaporation!!
As a bonus when you distill methylene chloride ,you can immidiately reuse it for the next batch( no need for purification). thus you save money and time both by distillation instead of evaporation by heating.


Methylene chloride is a chemical used as a solvent to extract caffeine from many raw materials. Molecules of caffeine bond to molecules of methylene chloride. The materials are softened in a water bath or in steam. The next step is to process the materials with methylene chloride by either of two methods:
Using the "direct" method, caffeine is removed by directly soaking the materials in methylene chloride.
Using the "indirect" method, caffeine, which is water soluble, is extracted by soaking the materials in water. Many of the flavors and oils are also extracted during this process, so the solution is treated with methylene chloride and then returned to the material for reabsorption of the flavorings.

Answer 2

just use a rotavapor and you recover the methylene chloride and the dry caffeine.