Distillation of ethyl ester and butyl ester. The separation of ethyl ester and butyl ester is related to the difference in physical properties. For ethyl ester, it is more active and has a slightly lower boiling point; for butyl ester, it is relatively stable and has a slightly higher boiling point.

At the beginning of distillation, the device is complete, and it is refined. Mixed esters are contained in the kettle, and heat is applied under fire. Because of the low boiling point, ethyl ester is vaporized first, rises up, and is reformed into a liquid through the condenser, which is collected in other vessels. This is the state of initial distillation, and ethyl ester is mostly concentrated here.

However, if you want a pure product, you need to re-distillate it. The liquid of the first distillation, impurities still exist, re-enter the kettle, and heat it at a controlled temperature. When the boiling point of ethyl ester is reached, the ethyl ester is vaporized and escaped again, and it is collected by fine condensation, resulting in a purer ethyl ester.

As for butyl ester, after the initial distillation, the rest of the kettle is mostly butyl ester and high boiling point impurities. When heated to the boiling point of butyl ester, butyl ester is vaporized, and after condensation into a liquid, the product of butyl ester is also obtained.

The essence of distillation is to care about accurate temperature control, observe the state of gasification, and be careful about condensation. If the temperature is too high, impurities will easily come out with the ester; if it is too low, the vaporization will be slow and time-consuming. The condenser needs good heat conduction to make the steam quickly cool into a liquid without loss.

From this perspective, the distillation of ethyl ester and butyl ester is based on physical properties, techniques are essential, and hard work is required to obtain the best pure ester.