Question 2 [30 marks] A tray distillation column fractionates a mixture of n-hexane, n-heptane, and n-octane. The liquid leaving the last tray (lowermost tray) is introduced to a reboiler which operates

at 413 K and 3.07 bara. The composition of the liquid entering the reboiler is shown in Table 2. Table 2. Composition of liquid entering reboiler. Composition (mol basis) Component n-hexane n-heptane n-octane 0.12 0.78 0.1 a. Calculate the boil-up ratio of this operation. [10 marks] b. Determine the composition of the vapor entering the last tray (lowermost tray) of the column. [10 marks] 2 c. There is a suggestion from a newly joined process engineer to increase the reboiler temperature to 420 K while maintaining the pressure and feed composition the same. Evaluate the feasibility of this suggestion. You need to support your evaluation with detailed calculations. [10 marks]