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“The temperature at the top of the distillation tower increases, and the content of heavy components in the top product increases." Can anyone please explain, I understand exactly the opposite! :L
Distillation is a complex system problem. If you do not consider it systematically but study a single variable, there will be no rules.
Generally speaking, when other influencing factors remain unchanged, reducing the reflux volume at the top of the distillation tower will increase the top temperature, which will increase the content of heavy components in the top product.
This post was last edited by CHANGBAISHI on 2020-3-12 16:20 Distillation towers are widely used. What does the so-called "heavy component" mean? It is best to create a small schematic diagram to illustrate the properties of the medium to facilitate discussion.
The light and heavy components are for the raw material components you are processing. From the top to the bottom of the distillation tower, the components become heavier in sequence. After observation, you will find that the temperature increases in sequence. So when the temperature at the top of your tower increases, relatively heavier components are extracted from the top of the tower, which means that the heavy components increase. You should be able to understand this!
When the temperature is high, things with high boiling points are distilled out, and of course heavy components increase.
Then I have always understood it like this, "Heavy components are in liquid state, and light components are in gaseous state." Is this understanding completely wrong?
You can learn about the two concepts of "distillation range" and "boiling range". The fractions flowing out of our distillation tower at different locations are different. This distinguishing point is temperature. You can think of the liquid components as overweight components that cannot be vaporized under the existing process conditions, while the components in the tower are progressively heavier from top to bottom!
The situation you mentioned is generally in two states. One is that as the light components continue to evaporate, the heavy components at the top of the tower increase and the temperature rises.； In another situation, the tower must be overflowing due to improper temperature control of the tower kettle.