2.) Refer to one of the BP-Composition curves for Cyclohexane - Toluene above. Starting with a mixture of 15% cyclohexane and 85% toluene, to produce distillate having a purity of greater than 90% cyclohexane, what is the minimum number of theoretical plates that a fractional distillation apparatus would need? Show a sketch of how you determined this.
3.) How many simple distillations would produce the same result in Question 2.)?
Each step is equivalent to a simple distillation. The graph shows that starting with a mixture that is 20% cyclohexane and 80% toluene, a fractionation column having an efficiency equal to three theoretical plates would be needed to result in distillate that is 95% pure. A fourth theoretical plate would result in distillate that is about 99% pure cyclohexane. BOILING POINT- COMPOSITION CURVE MOI 90 Cyclohexane 100 90 80 70 60 50 40 30 20 10 0 115 110 u 105 100 Vapor 90 F 85 80 75 Liquid 0 10 20 30 40 50 60 70 80 90 100 M0196 Toluene >
