Distillation tower
Thread Content
As the content of heavy components in the feed to the distillation column increases, the temperature at the bottom of the column rises. How can this phenomenon be explained?
As the content of heavy components in the feed increases, the amount of vaporization decreases. Since vaporization is an endothermic process, less vaporization means less heat absorption, and therefore the temperature at the bottom of the tower rises.
The question posed by the original poster is quite simple: the difference between heavy components and light components lies in their boiling points; once this is understood, it becomes easy to grasp
The view on the 3rd floor is correct: as the Reconstituted components increases, to maintain the same operating conditions (pressure, top temperature of the tower), it is necessary to increase the bottom temperature of the tower. Everyone, share your opinions
Agree with the opinion from the second floor. In feed of the same mass, if the heavy components increase, according to the energy balance of the entire tower, less heat is carried away by the light components, and therefore more heat remains at the bottom of the tower. There is another reason as well: when the heavy components increase, under the same conditions, the liquid level at the bottom of the tower must rise, and the residence time of the fluid at the bottom of the tower increases, which is also a cause of the temperature rise.
As the Reconstituted components increases, the liquid load in the retention section rises, so it is necessary to increase the heating amount\
In my opinion: I agree with the view expressed on the 3rd floor. Under the same system pressure, for a distillation column that is in equilibrium, an increase in the heavy components at the bottom of the column leads to an increase in the boiling point of the mixture at that location. The temperature will increase accordingly.
Recombinant components have high boiling points and high heat of vaporization; to achieve the same pressure, more heat is required, causing the temperature to rise accordingly
2# No. 18 Agrees with the view
The so-called heavy components are those with high molecular weights and high boiling points. If there is an excess of such components in the feed, and all other conditions remain unchanged, then a relatively larger proportion of heavy components will be present in the vaporized stream from the reboiler, which leads to an increase in temperature
If the feed has changed and you didn’t mention the reboiler temperature, yet the temperature inside the tower has increased, it should be the value for floor 2, right?