2- A continuous fractionating column, operating at atmospheric pressure, is to be designed to separate a mixture containing 15.67 per cent CS,and 84.33 per cent CCI, into an overhead product

containing 91 per cent CS, and a waste of 97.3 per cent CCI, all by mass. A plate efficiency of 70 per cent and a reflux of 3.16kmol/kmol of product may be assumed. Using the following data, determine the number of plates required. The feed enters at 290 K with a specific heat capacity C, of 1.7 kJ/kgK and a boiling point of 336 K. The latent heats of CS, and CCI,are 25.9 kJ/kmol. WHERE Mw of C=35.5g/mol, C=12 , S=32 CS, in the vapour 0 8.23 15.55 26.6 33.2 49.5 63.4 74.7 82.9 87.8 93.2(Mole per cent): CS, in the liquid 0 2.36 6.15 11.06 14.35 25.85 33.0 53.18 66.30 75.75 86.04(Mole per cent):