solution

17.6, 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% ethanol in water. with traces of acetaldehyde and fusel oil. is concentrated to 50 mol%. The concentration of alcohol in the wastewater is reduced to less than 0.1 mol%. 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 °C. The column will operate at I atmosphere. Detenmine: a. The number of theoretical stages b. An estimate of the stage efficiency C. The number of actual stages needed Design a suitable sieve plate for conditions below the feed point. Equilibrium data for the system ethanol-water, at 760 mmHg, mol fractions ethanol: Liquid Phase 0.019 0.072 0.124 0.234 0.327 0.508 0573 0.676 0.747 0.894 Vapor Phase boiling Point C 95.5 89.0 85.3 82.7 81.5 79.8 793 78.7 78.4 78.2 0.170 0.389 0.470 0.545 0.583 0.656 0.684 0.739 0.782 0.894 Reference: Carey and Lewis (1932)