The feed mole fractions are methanol \(=0.2\), ethanol \(=0.5\), and \(1-\) propanol \(=0.3\). The feed is at \(75^{\circ} \mathrm{C}\), the flow rate is \(1000.0 \mathrm{kmol} / \mathrm{h}\), and pressure is at 1.0 bar. We want each product to have mole fraction of 0.99 or greater. Use Figure 11-9A (methanol product distillate from the first column, ethanol product distillate from second column, and 1propanol product bottoms from second column). Operate both columns at a constant pressure of 1.0 bar. Both columns have total condensers and kettle-type reboilers. Each column has only one feed. Column 1 has \(\mathrm{N}(\) Aspen notation \()=40\). Column 2 has reflux ratio \(=2.0\).
Preliminary: What VLE correlation will you use, and why?

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First, find conditions that give methanol, ethanol, and 1-propanol products that are all 99.0 mol% or greater. Record the conditions that worked: Column 1. Aspen N = 40 (given), Aspen feed location condition 1 on the Setup- (e.g., distillate flow rate) and Configuration tab value Configuration tab Column 2. Aspen N = operating operating condition 1 Initial results: (e.g., 3 operating condition 2 on the Setup- and value Aspen feed location = on the Setup-Configuration distillate tab flow rate) and value ; reflux ratio = 2.0 (specified). Methanol mole fraction in methanol product: Ethanol mole fraction in ethanol product: 1-Propanol mole fraction in 1-propanol product: Second, for column 1, keep all variables except for the reflux ratio and the feed location constant. Find the optimum feed location for N = 40. Then, with N = 40 and the optimum feed stage, find the lowest reflux ratio that gives the methanol mole fraction within the range 0.99000 to 0.99004. Column 1.Aspen N reflux ratio = product = 40(specified), Aspen optimum feed location = methanol mole fraction in methanol Third, with changes in column 1, the products from column 2 may no longer meet specifications. If this is the case, find conditions that work but keep the reflux ratio = 2.0 and do not change column 1. If column 2 already meets the specifications or once column 2 meets the specifications, keep all variables except for N and the feed location constant. Find the optimum feed location. Reduce N as much as possible while using the optimum feed location and obtaining ethanol and 1-propanol product mole fractions that are greater than or equal to 0.99000. Column 2.Aspen N = Aspen optimum feed location = operating condition 1 on the Setup-Configuration tab (e.g., distillate flow rate) and value reflux ratio = 2.0. Ethanol mole fraction in ethanol product: 1-Propanol mole fraction in 1-propanol product: