In the manufacture of absolute alcohol by fermentation, the product is separated and purified using several stages of distillation. In the first stage, a mixture of 5 mol per cent ethanol in water, with traces of acetaldehyde and fuel oil, is concentrated to 50 mol per cent. The concentration of alcohol in the wastewater is reduced to less than 0.1 mol per cent. Design a sieve plate column to perform this separation, for a feed rate of 10,000 kg/hour. Treat the feed as a binary mixture of ethanol and water. Take the feed temperature as 20 ŽC. The column will operate at 1 atmosphere. Determine:
a) the number of theoretical stages,
b) an estimate of the stage efficiency,
c) the number of actual stages needed.

d) Design a suitable sieve plate for conditions below the feed point.