The composition of the feed to a debutaniser is given below. make a preliminary design for a column to recover 98 per cent of the n-butane overhead and 95 per cent of the isopentane from the column base. the column will operate at 14 bar and the feed will be at its boiling point. use the short-cut methods and follow the procedure set out below. use the de priester charts to determine the relative volatility. the liquid viscosity can be estimated using the data given in appendix d.
(a) investigate the effect of reflux ratio on the number of theoretical stages. (b) select the optimum reflux ratio. (c) determine the number of stages at this reflux ratio. (d) estimate the stage efficiency. (e) determine the number of real stages. (f) estimate the feed point. (g) estimate the column diameter.

feed composition (kg/h):
propane c3 (910 kg/h)
isobutane i-c4 (180 kg/h)
n-butane n-c4 (270 kg/h)
isopentane i-c5 (70 kg/h)
normal pentane n-c5 (90 kg/h)
normal hexane n-c6 (20 kg/h)