Problem 2. Distillation with multiple units (60 points) One hundred kilomoles per hour of a liquid mixture (the process feed) containing 30.0 mole% benzene (B), 25.0% toluene (T), and the balance xylene (X) is fed to a distillation column. The bottoms product contains 98.0 mole% X and no B, and 96.0% of the X in the feed is recovered in this stream. The overhead product is fed to a second column. The overhead product from the second column contains 97.0% of the B in the feed to this column. The composition of this stream is 94.0 mole% B and the balance T. a) Assume that the process is continuous and at steady-state. Draw and label a flowchart of the process. (A draft flowchart is shown below, but note that this is not properly labeled.) b) Do the degree-of-freedom analysis to prove that the molar flow rates and compositions of all process streams can be calculated from the given information. (Hint: You would have to do the degree-of-freedom analysis on all systems around which material balances can be made; there are 3 of them.) c) Indicate the order that you will solve the equations to calculate the unknown process variables. In each equation (or pair of simultaneous equations), circle the variable(s) for which you would solve. Do not do the calculations. (See example in class). d) Solve for the value of all the unknowns (flowrates and mole fractions). 100 kmols/h COLUMN 1 D1 kmols/h COLUMN 2 D2 kmols/h Process feed 30.0 mole%B 25.0 mole %T balance is X Overhead product 1 with B, T, and X Overhead product 2 94 mole%B balance is T (contains 97.0% of the B in the feed to this column) B1 kmols/h B2 kmols/h Bottoms product 2 (may contain B, T, and X) Bottoms product 1 98.0 mole%X There is no B (contains 96.0% of the X in the feed to this column)