What are the precautions for extractive distillation?

As a large amount of extractant is added (xs>0.6 is generally required), the amount of descending liquid in the tower is far greater than the amount of ascending steam, resulting in poor vapor-liquid contact. The tray and hydrodynamic conditions should be considered in the design.

Because the relative volatility between components is adjusted by the amount of extractant, when the top product is unqualified, it can not be adjusted by increasing reflux. The general adjustment methods are: ① increase the amount of extractant; (2) reduce the feed rate, at the same time reduce the top of the tower product extraction;

When deciding the tower diameter and designing the tray structure, N- methylmorpholine manufacturers should not only calculate according to the steam quantity, but also pay attention to a large amount of extractant in the liquid stream.

The following professional chemical raw materials companies introduce the method of selecting extractant for everyone. The selection principle of extractive distillation additives (also known as extractant) is:

(1) high selectivity, that is, the relative volatility between components can be greatly increased by adding a small amount of additives;

(2) The volatility is small, that is, it has a boiling point much higher than that of the feed liquid component;

(3) It has enough mutual solubility with the raw material liquid, and there is no liquid phase separation phenomenon on the tray;

④ The source is abundant and the price is cheap. Water and some polar organic compounds are the most common additives.