Regarding the issue of distillation component concentrations
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Taking alcohol recovery as an example, during reflux, if the alcohol concentration in the gas phase is much higher than that in the liquid phase, will the concentrations of both phases (referring to the light component) still be higher in the gas phase and lower in the liquid phase after mass and heat transfer?
This is absolutely necessary! Isn’t that right?
For the equilibrium relationship y=mx, look at the coefficient m. If m=100, y=0.9 in the gas phase and x=0.01 in the liquid phase, then there is still a trend of y increasing while x decreasing ； Conversely, if x becomes 0.001, then y must decrease while x must increase, which corresponds to the transfer of alcohol from the gas phase to the liquid phase
The reflux liquid is what condenses from the gas phase; why are the compositions of these two streams so different?
Can this limit value be calculated?
Does your reflux not go through condensation?
It’s not complete distillation; to be more precise, the concentration of the feed is very low, and then it is pumped back from the bottom of the tank to the top as reflux. I’m not sure if this explanation is clear enough
Sure, you can check the saturated vapor pressure by using Raoult’s law for calculations