NRB: Single-Unit Example 2

Another Single Unit Material Balance Example

One thousand kilograms per hour of a mixture containing equal parts by mass of methanol and water is distilled. Product streams leave the top and bottom of the distillation column. The flow rate of the bottom stream is measured and found to be 673 kg/h, and the overhead stream is analyzed and found to contain 96.0 wt% methanol.

Determine the flow and composition of all of the streams.

The first step is to draw the flowchart. Let's start there...

How many Unknowns are there?
How many different Species (material balances) are there?
How many Process Specifications are we given?
How many Physical Constraints are there?
The total number of Degrees of Freedom is