Regarding atmospheric pressure columns, why does an increase in the amount of product taken off via side streams lead to a rise in temperature?
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As the title suggests, regarding atmospheric distillation columns, why does an increase in the amount of product taken off via side streams lead to an increase in the temperature of those side streams? The explanation that LZ came up with is that more oil with a high temperature was drawn out, which caused the temperature to rise. Could any experienced expert provide a more academic and formal explanation?
Is it the increase in tower top temperature? Increasing the side-line reflux raises the tower top temperature, which will decrease it
An increased extraction volume indicates a higher bubble point temperature of the product, as well as a higher weight of the components
In a atmospheric pressure column, for each tray, there is a gas-liquid phase equilibrium. The more material that is taken off as a side stream, the lower the liquid load becomes, and this equilibrium is disrupted; it is necessary to establish a new equilibrium, which results in the heavier components moving upward and the overall temperature rising as well.
4th floor is correct. The withdrawal of side streams is generally limited; if it is too much, the equilibrium of the tower is disrupted and the reflux cannot be maintained!
Internal reflux decreases, the gas-liquid equilibrium is disrupted, the heavier components increase, and a new equilibrium is established
The amount of material drawn off through the side line is high, which reduces the internal reflux; this disrupts the equilibrium, and it becomes necessary to re-establish this equilibrium, resulting in the upward movement of heavier components as well as an increase in temperature.
It’s actually an issue of internal recirculation; if too much is pulled out, the internal recirculation decreases