Degrees of Freedom: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

Example Problem 1

How many degrees of freedom does this column have?

image for an example problem in the degrees of freedom module
Example Problem 2

A feed containing equimolar amounts of methanol and water is mixed with 10 moles of a 40% aqueous methanol stream. The mixture enters a separation unit that creates two streams. A top stream exits that contains 70 mol% methanol and the rest water. The other stream, which is 70 moles, enters a second separation unit. A top stream exits the second unit as a 50% methanol/50% water mixture. The other stream is unknown. If the fresh feed to the system is 100 moles (the equimolar mixture) and the two top streams exiting the separation units have the same flow rate, find the molar flow rate and composition of the other stream exiting the second separation unit.

Image to help describe an example problem for the Degrees of Freedom Module