Q2

2) A process is to be designed in order to deliver an overhead product comprising 80 mol% benzene from a mixture containing 68 mol% benzene and 32 mol% toluene. The following methods are considered for this separation. In both methods, the pressure is assumed to be atmospheric. For each method, calculate the moles of product per 100 moles of feed, and the number of moles vaporised per 100 moles of feed. a) Continuous flash distillation b) Continuous distillation in a still fitted with a partial condenser, in which 55 mol% of the entering vapours is condensed and returned to the still. The partial condenser is constructed in such a way that vapour and liquid leaving it are in equilibrium, and the holdup in it is negligible