Estimating Pure Component Properties in Hysys

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Exercise DP.1:

Estimating Pure Component Properties in Hysys

Workshop Report Requirements:

1. Create a graph of the vapor pressure in psia of cyclohexanol, cyclohexanol and high boiler as a function of temperature from 50 to 450 F. Print and submit these graphs. 2. Compare the pure component critical properties ( Critical Temperature, Critical Pressure) given in the design problem statement against the values used by Hysys. ( To view properties of a component, View the Basis Environment and then click the component of interest. You can now View the component properties. Include this comparison in your report.

To accomplish this, it will be necessary to choose the appropriate base property package ( to select the thermodynamic property models to be used in the simulation) , add the components, and finally either tabulate or plot the desired data as a function of temperature. It should be noted that the one component, the high boiler, is not listed in the Pure Component Library. So we will have to create a hypothetical compound similar to the highboiler and generate its pure component properties.

Instructions for Preparing the Input to this Problem:

1) Open Hysys and from the File Menu, choose New / Case. This will open the Simulation Basis Manager as shown in Figure 1.

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Figure 1:Simulation Basis Manager

2) First, the desired fluid package ( ie. thermodynamic models) needs to selected. This is accomplished by clicking the Add button. The Fluid Package: Basis 1 screen will appear. From the list of packages choose the Wilson method as it is known to be accurate for this system. The Vapor model should be set to SRK ( Soave-Redlich-Kwong) as the system is not ideal. Note that the default selection is Ideal. If you click on this cell you can change the selection. The value entry area is located at the top of the wndow. There is a small pull down arrow which shows you available options. Select SRK from this option set. 3) Next click on the Components Tab.

To Add Components Listed in the Component Library:

1) The components that are listed in the library are cyclohexanol, cyclohexanone, and hydrogen. To add these components do the following:

a) Type the name of the component to be added in the Match box, for example hydrogen. b) Hydrogen will appear in the component box. Highlight it and click on the Add Pure button. This is all that is necessary to add a component that is listed in Hysys’s library. Follow the same procedure and input cyclohexanol and cyclohexanone. The results are shown in Figure 2.

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Figure 2:Selected Components
Creating the High Boiler:

1) Select the Hypothetical Option under Add Comps. The Hypothetical Manager page will appear as shown in Figure 3.

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Figure 3: Initial Screen for Creation of Hypothetical Group

2) Click on the Quick Create A Hypo Component button. This will bring up the screen shown in Figure 4.

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Figure 4: Component Builder
Note: the component’s name can be changed by simply clicking once on the cell and then typing High Boiler followed by enter. 3) The highboiler will be defined by inputting it's structure into HYSYS. HYSYS will then be able to estimate the pure component data for the component. Click on the Structure Builder button. This will bring up the following screen shown in Figure 5.

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Figure 5: UNIFAC Component Builder

4) From this screen, one will be able to build a molecule based on sub-groups. Figure 6 is the structure for the highboiler.

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Figure 6: Molecular Structure of High Boiler

5) The results in Table 1 show what sub-groups are needed.
Table 1

Groups Necessary to Build the High Boiler

|Sub-Group |Number to Add | |CH2 |9 | |CHOH |1 | |CHOCH |1...
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