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Unformatted text preview: Homework 5 Problem 2 HYSYS Thermodynamics COM Interface™ K-values
20 points possible due Friday September 30, 2011 Grader: Israel Problem Statement: A sieve tray distillation column is to be used to separate a propane/propylene mixture. The multicomponent feed to the column is completely vapor at a temperature of 43.3 oC, a pressure of 1668 kPa, and a composition shown below. m , kg/s
m , kg/s
Component ‐6 Acetylene 1.3 X 10
MAPD* 5.4 X 10‐4 Ethylene 1.3 X 10‐6 1,3‐Butene 3.7 X 10‐4 Ethane 3.3 X 10‐4 i‐Butene 1.9 X 10‐4 Propylene 6.41 1‐Butene 1.2 X 10‐4 Propane 4.62 *MAPD refers to the C3 acetylenes (C3H4), methylacetylene and propadiene. Determine the K‐values and relative volatilities for every component versus the heavy key. Method of Solution: Use the Shortcut Distillation Column in DISTILTM to simulate the design generated by hand calculations to separate the feed mixture. Solution: 1) Open the COMThermoTM program. All Programs → AspenTech → Process Modeling v7.2 → Aspen HYSYS Thermodynamics COM Interface 2) Start a new case by clicking Managers from the toolbar and then Fluid Package Manager. 3) The Fluid Package Manager window will open. Click the Add a New Fluid . Since the process streams are hydrocarbon mixtures, Pkgs button select the Peng‐Robinson EOS for both the liquid and vapour states on the Property Package tab. Page 1 of 6 4) Click on the Components tab next. Add the process components by typing the name in the Match box, highlight the appropriate component, and click Select. When the Selected Components List is complete, close the Fluid Package window. 5) On the toolbar click Managers and select Thermodynamic Workbench Manager… Page 2 of 6 6) Highlight Phase Equilibrium and click Add… 7) Select Fluid 1 from the Fluid Package drop down menu. 8) Click on the X to select up to 3 components to be evaluated. Select the light key propylene (C3=) and the heavy key propane (C3). Page 3 of 6 9) Click the plots tab. Keep the analysis type as constant pressure, select the K‐value plot, and enter the column pressure, 1668 kPa. 10) To change the number of significant figures, right click in the graph area and select Graph Control. Click on the Format button under the Axes tab and enter the correct number of significant figures. Page 4 of 6 11) Calculate the relative volatility = Ki/KHK based on the graph results. 12) Change the plot to relative volatility using the drop down menu and compare your results. 13) Click Add on the Workbench Manager window to add another plot. Page 5 of 6 14) Select acetylene and propane (HK) and make the K‐value plot. Calculate the relative volatility and compare the results to the relative volatility plot. Page 6 of 6 ...
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This note was uploaded on 11/14/2011 for the course CHEN 4520 at Colorado.