The mathematical model of the column is obtained by performing a total mass balance and partial mass balances to component “ i .” The Fenske-Underwood-Gilliland method is used to find the functional relationship between the compositions of the bottom and the dome of the column.
How do you select a light key and a heavy key?
If you line up all the components in the order of their boiling points, and draw a line between two of them, the more volatile component is called the light key and the less volatile component is called the heavy key. For this example, you choose the first column in the process shown in Fig. 5-4.
What are the disadvantages of vacuum distillation?
The main and most obvious disadvantage of vacuum distillation is the high cost of equipment. Only a few can afford to pay for this hobby. And this despite the fact that the advantages of the method have not yet been proven.
What is light and heavy key?
Combo box which lets the user to choose the light key in the inlet mixture. Light key is the most volatile (e.g. ethanol), while heavy key is the less volatile (e.g. water). Heavy Key in Feed. String. Combo box which lets the user to choose the heavy key in the inlet mixture.
Does Fenske equation include reboiler?
The Fenske equation applies to distillation systems with constant relative volatility. Note that the form of the Fenske equation shown calculates the minimum number of plates; it does not include the reboiler (hence the -1 on the right hand side).
What is weeping in distillation column?
what is weeping in distillation? Weeping is when liquid flows downward through the holes in a distillation tray. If the vapor rate is too low the liquid may be able to drop to the next stage through the holes, resulting in less than optimal vapor/liquid contact (and therefore less than optimal separation).
What is Theta in Underwood equation?
where Underwood constant, θ is calculated as the root of following equation: where, 1 < θ < αLK and q is the quality of feed. Select an operating reflux ratio, R as a factor of minimum reflux ratio, typically a factor of 1.2 is considered. Number of stages, N is calculated based on Gilliland’s correlation.
What is the major advantage using vacuum distillation?
The primary advantage of vacuum distillation is that it allows for distilling heavier materials at lower temperatures than those that would be required at atmospheric pressure, thus avoiding thermal cracking of the components.
Why is vacuum distillation used?
A vacuum distillation is used when the boiling point of the compound (or the solvent) is too high (Tb>150 oC) in order to distill the compound (or the solvent off) without significant decomposition. The setup is similar to a micro-scale or semi-macroscale distillation.
