hysys tutorial

Section II: Tutorials

Tutorial 1

Physical Properties

Problem 1: Physical Properties of Water

Calculate the properties of a stream of water at 25 ºC and 1 atm with mass flow rate of 125

kg/hr.

Process Simulation using HYSYS66

Solution:

Follow the step-by-step instructions to solve the problem.

1- Open a new case.

2- Add a new component list

Tutorial 1 Physical Properties 67

3- Select water from the Components list and then close the active window by clicking on

cross button.

4- The cross button is not seen on the figure and you could move the active window to see

the cross button in order to close it.


5- Select the Fluid Package (Make sure selecting Component List -1in the component list).

6- Add a new Fluid Package

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7- Select the Peng Robinson or SRK equation of state from Property Package.

8- Close the Fluid Package by clicking on cross button. After this step, it is also possible to

import /export the Fluid Package. Enter to Simulation Environment.


9- Drag a material stream to the PFD. (Choose the stream from the Object Palette by

pressing F4 or by F11). Rename the stream if needed.

10- Save the simulation work (e.g., problem-1).


11- For the N components stream, N+2 parameters are needed. Enter 2 out of 3 (temperature,

pressure and vapor fraction) and mass flowrate in the Worksheet/Conditions page:

12- Enter 1 for mole fraction of water in the Worksheet/Composition page.


13- The stream properties can now be calculated (seen in the Worksheet/Properties page).

Items in blue and black indicate user-defined and calculated properties, respectively.

14- By putting the curser on the stream, the Fly-By window appears showing the main

properties of the stream.


Problem 2: T-xy diagram

Plot the T-xy diagram for the binary mixture of 1-butanol and water.


Solution:


1- Open a new case.



3- Select 1-butanol and water from components list then close the active window by

clicking on cross button.





6- Add a new Fluid Package.


7- Select the UNIQUAC activity model from Property Package.

8- Close the Fluid Package by clicking on cross button. After this step, it is possible to

import/export the Fluid Package. You may now enter to Simulation Environment.


9- Drag a material stream to the PFD. (Choose the stream from the Object Palette by

pressing F4 or by F11). Rename the stream to H2O.



11- Select another material stream for 1-butanol. Define both streams (100 °C and 1 atm) as

outlined in the previous problem.

12- Enter the molar flow rate for water stream (e.g., 0.7 kmole/hr) and its composition (mole

fraction=1) in order to fully define this stream. Enter the composition of 1-butanol

stream (mole fraction=1).


13- Use the set function from the Object Palette to keep the total molar flow of these streams

equal to 1. In this way, independent mole fraction variables could be defined for mixture.

14- Double click on the set icon to define the target variable (1-butanol molar flow).


15- Choose H2O as a source stream.

16- Click on the parameters section to define the multiplier and offset in order to keep the

total molar flow rate of these streams equal to 1. The molar flow rate of the second

stream is adjusted so that the total molar flow rates of these two streams remain constant.


17- There are different ways to keep the total molar flow rate of these streams constant

instead of using set. For example, use a mixer (from the object pallet) and set the molar

flow rate of outlet stream to 1 kmole/hr. The flow rate of 1-butanol stream is adjusted

accordingly.

18- Connect the inlet and outlet streams by double clicking on the Mixer. (The stream

properties can now be calculated).


19- In order to plot the T-xy diagram, the bubble and dew point should be calculated for the

water stream flowrate varying from 0 to 1. A Heater and a Cooler are added to the flow

sheet for this purpose.

20- Assume no pressure drop in the Heater and the Cooler (Constant pressure for T-xy).


21- To calculate the bubble and dew point for a given flowrate of water stream (0.7

kmole/hr), set the vapor fraction at the exit of the Heater and Cooler equal to zero and

one, respectively.

22- To plot the figure, press Ctrl+D to open Databook.


23- Click on insert button in order to sample the variables from the flowsheet.

24- Sample the variables from the flowsheet (temperature for S-bubble stream, S-dew stream

and flowrate of water stream).


25- Go to case studies and add a new case.

26- Choose the molar flow as an independent variable (to represent x in T-xy) and the

temperatures as dependent variables (to represent T in T-xy) and then press view.


27- Specify the low, high bound and step size values of independent variable and press start.

28- After the completion of simulation, press Results button to view the T-xy diagram.

.Different thermodynamic models may be selected to generate T-xy diagram and to compare the

simulation data with the experimental data to figure out the proper physical property models to be employed in simulation.


Problem 3 Flash Calculations

Consider a stream of gas (T=40 ºC and P=30 kg/cm2) containing methane, ethane, propane,

n-butane and n-pentane with molar flow rates of 60, 25, 15, 10 and 10 kmole/hr, respectively.

Calculate:

a) Pressure of dew point at 40 ºC.

b) Pressure of bubble point at 40 ºC.

c) Temperature of dew point at 30 kg/cm2.

d) Temperature of bubble point at 30 kg/cm2.

e) Stream enters to a separator. Calculate properties of outlet streams.

f) Plot outlet molar flow rate of ethane in the gas stream as a function of the operating

temperature (sensitivity analysis).

g) Adjust the drum temperature to reach 50% liquid.


Solution:


1- Open a new case.



3- Select components from components list, then close the active window.







7- Select the Peng Robinson equation of state from Property Package.

8- Close the Fluid Package by clicking on cross button. After this step, it is possible to

import/export the Fluid Package. You may now enter to Simulation Environment.


9- Drag a material stream to the PFD and enter two out of three properties (temperature,

pressure and vapor fraction) in the Worksheet/Conditions page.



11- Enter molar flow rate of components in the Worksheet/Composition page.

8- By pressing OK button, the properties of stream will be calculated.


a) For calculating the dew point pressure at 40 ºC, first erase the pressure of the stream. Then

enter 1 in vapor/phase fraction of stream. (Pressure of dew point is 1105.5 kPa).

b) For calculating the bubble point pressure at 40 ºC, enter 0 in vapor/phase fraction of

stream. Pressure of bubble point is 10775 kPa.


c) For calculating the temperature of dew point, erase the temperature, and then enter 30

kg/cm2 for pressure and 1 for vapor fraction. The dew point temperature is 68.092 ºC.

d) For calculating the temperature of bubble point at 30 kg/cm2, enter 0 for vapor/phase

fraction of stream. Temperature of bubble point is calculated to be -73.314 ºC.


e) Return the stream conditions (temperature and pressure) to initial conditions (40 ºC and

30 kg/cm2). Then put a separator on the PFD from the Object Palette (F4).

Double click on the separator to open it. Enter inlet and outlet vapor and liquid streams on

the Design/Connections page. The calculation is performed for an adiabatic separator

immediately.


The properties of streams are seen in the Worksheet/Conditions page.

f) To complete a sensitivity analysis, go to Tools/Databook or press Ctrl+D.


At the first page of Databook, variables appear, use insert to sample variables from

flowsheet.

From the variable navigator, select the object and variable, e.g., choose 1 as object and its

temperature as variable, press add button to select another variable.


Select molar flow rate of ethane from the vapor outlet stream (stream vap).

Then go to the Case Studies page and add a new case study by clicking on the Add button.


Specify temperature as an independent and molar flow rate of ethane as a dependent variable.

Click on the view button and enter low, high bonds and step size values for the independent

variable. Number of states will be calculated by HYSYS.


Press Start button and then go to the Results page to see the plot or table. The results may be

exported to any spreadsheet software for further processing.

g) In order to adjust the drum temperature to reach the 50% liquid, the duty should be

specified for drum to be able to run it isothermally.


At this stage, the specifications for the drum are incomplete. The drum temperature (vap

stream temperature) is now specified to run it.

Close the active window. The drum temperature is now initiated. It could be changed by the

Adjust function to control the bottom flow rate. Drag the adjust function from the object

pallet to the PFD.


Use the spreadsheet to define the new variable being the ratio of liquid stream to feed stream.

Double click on spreadsheet and import the flowrate variables from the flowsheet.


Click on the spreadsheet button and create a new variable (liquid_to_feed_ratio) and

calculate its value (the formula used in cell B4 is the ratio).

Close the active window and double click on Adjust. Specify the drum temperature (vap

stream) as the adjusted variable and the value calculated in spreadsheet as the target value.

Then click on start.


The calculation is now completed.

Click on the Monitor button to view the Adjusted temperature.


Problem 4: Plot the physical and thermodynamic properties

Plot vapor pressure and surface tension of dimethylsulphide as a function of temperature in a

desired range.


Solution:


1- Open a new case.

2- Add a new component list.


3- Select components from components list.







7- Select Peng Robinson equation of state from Property Package.

8- Close the Fluid Package by clicking on cross button. Enter to Simulation Environment.


9- Drag a material stream to the PFD and Rename it to “Feed”. Enter temperature, pressure

and molar flow in the Worksheet/Conditions page.

10- In Worksheet Compositions page, enter mole fraction of the components. The stream is

now calculated for a base case.



12- To plot the surface tension of dimethylsulfide vs. temperature, go to Tools/Databook or

press Ctrl-D.


13- The first page of the Databook is variables.

14- Click on Insert button to sample and add the variables from the flowsheet. Herein,

temperature of feed stream is sampled from the variable navigator.


15- Also, insert the surface tension of the Feed stream.

16- Go to case studies page and add a new case study. Select the temperature as an

independent variable and the surface tension as the dependent variable.


17- Go to the view page and enter low, high bounds and step size values for independent

variables (e.g., -250, 50 and 20).

18- Click on start button. Then go to the Results page to view the results. The results are

shown both in the graph and table format.


19- To plot the vapor pressure of dimethylsulfide vs. temperature, drag the spreadsheet

function to PFD.

20- Click on spreadsheet, press add import button to import the vapor pressure equation

coefficients (10 coefficients) from the navigator scope Basis.


21- Use the Antoine vapor pressure expression where 6 coefficients from a-f are needed as

extracted from the scope navigator (Basis).

22- The coefficients are now imported to the spreadsheet. Press spreadsheet button in order

to enter the equations.


23- Enter the equations in the spreadsheet to complete the calculation. In cell B9, the

temperature is calculated in K.

24- By clicking on the Formula button, all equations used in the spreadsheet are shown.


25- Go to Tools/databook or press Ctrl-D.

26- The first page of Databook is variables.


27- Click on Insert button to sample and add the variables. Herein, the vapor pressure of

methylsulfide is sampled from the Spreadsheet object.

28- Press OK. The variable is now added to the Databook. Click on Case Studies.


29- Go to Case Studies page and add a new case study. Select the temperature as an

independent variable and the vapor pressure as the dependent variable.

30- Go to the view page and enter low, high bounds and step size values for independent

variables (e.g., 0, 250 and 12.5).


31- Click on the Start button. After the completion of simulation, go to the Results page to

view the results. The results are shown both in the Graph and Table format.
