Condensers are an integral part of a distillation process. As we have seen, the vapor feed from the distillation column can enter either a partial condenser or a complete condenser. Consider a system where the vapor feed which is a mixture of benzene and toluene is fed to a condenser that operates at 80o C. The composition of the product from the condenser is 95 mol% B.
a. Estimate the minimum pressure that the condenser can act as a partial condenser. Is the temperature a dewpoint or bubblepoint temperature? Why?
b. Estimate the minimum pressure at which it can operate as a total condenser. Is the temperature a dewpoint or bubblepoint temperature? Why?
c. If the condenser operates as a total condenser and the mole ratio of reflux (recycle back to the column) to product is 1.5, find the molar flow rates and composition of the feed and reflux streams. The product flow rate is 50 kmole/hr.
d. Using the same flow rates as in part c, calculate the operating pressure of a partial condenser where the reflux and the overhead product are in equilibrium, as well as the compositions of the feed and reflux streams.
e. Draw a Pxy diagram that shows this process. Label the important points on it (in other words the points that allowed you to draw the diagram). The shape of the curve is not worth any points by itself.