Figure 1 shows a two-stage distillation process for the separation of a propylene-propane mixture to produce 99.5 mol% propylene and 96 mol% propane. 1000 kmol/h of liquid mixture containing 45 mol% propylene and 55 mol% propane is fed to the first distillation column, DC-1. The overhead product leaving DC-1 is fed to the second column, DC-2. The overhead product from the DC-2 contains 96% of propylene in the feed to DC-2. The bottom product from DC-2 consists of pure propylene and recycles to DC-1. n3 kmol/h 0.995 mol C3H6/mol na kmol/h DC2 1000 kmol/h DC1 n4 kmol/h n2 kmol/h 0.96 mol CH3 /mol Figure 1 Separation of propylene-propane in distillation column a) Redraw a completely labelled flowchart of the process. (3 marks) b) Perform the degree of freedom analysis (DOF) for DC-1 and the overall system. (4 marks) c) Calculate the molar flowrates of streams na, na, n3 and nu with their component molar fraction. (9 marks)