BATCH PROCESS !!!

First of all lets discuss DISTILLATION !!! Distillation is a method of separating two liquid from a  mixture based in the difference in their boiling points or simply , Volatility .

Distillation is a pure UNIT OPERATION , which may as well be the oldest known operation used for the separation of liquid mixtures .

Distillation is many types , now letz throw some light into the most basic one , called BATCH DISTILLATION or BATCH PROCESS generally .

BATCH DISTILLATION , as the name suggests is a form of distillation where the mixture is distilled in “ BATCHES ” , or small volumes.
It means the distillation is carried out separately for different batches . First a batch is distilled , then the second and then the third and so on .

This is in total contrast to the CONTINUOUS  DISTILLATION where the distillation goes on continuously , the feed is continuously fed and the distillate product is continuously collected .

In Batch Distillation ,  as in the case of simple distillation , the liquid mixture is fed into the distillation column where it is vaporised . The lower boiling liquid evaporates first leaving behind the higher boiling liquid , thus effectively separating the mixture . The only difference is it is done in batches .

Batch process is used :

a) for “intermittent” processes ( which alternatively cease and start ) .

b) for small volumes of feed , as it is feasible or say economical for only small volumes . Continuous Distillation does not work out well when we have to distillate only a domestic amount of mixture .

c) when we desire for “flexible” methods , yes , we can easily change the components of the mixture and obtain the same successful distillation process without applying any changes to the operation . No wonder it is called a Unit Operation !!!