A liquid mixture of 30 mole% benzene (B), 25 mole% toluene (T), 45 mole% xylene (X) is fed to a distillation column. The bottoms product contains 98 mole% X, and no B. Moreover, 96% of the X fed to the column is recovered in this bottoms stream. The overhead product is fed to a second distillation column, and the overhead product from the second column contains 97% of the B fed to the second column. The composition of the second overhead stream is 94%B and 6% T.
a. Draw and label a flow chart for this process and do a degree of freedom analysis to prove that, for an assumed basis, molar flow rates and compositions of all streams can be calculated.
b. Calculate the percentage of the benzene in the process feed (i.e., the feed to the first column) that emerges in the overhead product from the second column, and the percentage of the T in the process feed that emerges in the bottoms product from the second column.