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AspenTech Incorporations Aspen Hysys V8.8 Anees Ahmad Typewriter Cases Solved in Hysys Version 8.0 are same as Version 8.8 Anees Ahmad Typewriter Chemical Process Principles Matbal-001H Revised: Nov 7, 2012 1 Cyclohexane Production with Aspen HYSYS® V8.0 Lesson Objectives 1. Construct an Aspen HYSYS flowsheet simulation of the production of cyclohexane via benzene hydrogenation Become familiar with user interface and tools associated with Aspen HYSYS Prerequisites 2. Aspen HYSYS V8.0 Knowledge of chemical process operations Background/Problem 3. Construct an Aspen HYSYS simulation to model the production of cyclohexane via benzene hydrogenation. The simplified flowsheet for this process is shown below. Fresh benzene and hydrogen feed streams are first fed through a heater to bring the streams up to reactor feed temperature and pressure conditions. This feed mixture is then sent to a fixed-bed catalytic reactor where 3 hydrogen molecules react with 1 benzene molecule to form cyclohexane. This simulation will use a conversion reactor block to model this reaction. The reactor effluent stream is then sent to a flash tank to separate the light and heavy components of the mixture. The vapor stream coming off the flash tank is recycled back to the feed mixture after a small purge stream is removed to prevent impurities from building up in the system. The majority of the liquid stream leaving the flash tank goes to a distillation column to purify the cyclohexane product, while a small portion of the liquid stream is recycled back to the feed mixture to minimize losses of benzene. Process operating specifications are listed on the following page. Matbal-001H Revised: Nov 7, 2012 2 Feed Streams Benzene Feed (BZFEED) Composition (mole fraction) Hydrogen - Nitrogen - Methane - Benzene 1 Total Flow (lbmol/hr) 100 Temperature (°F) 100 Pressure (psia) 15 Hydrogen Feed (H2FEED) Hydrogen 97.5 Nitrogen 0.5 Methane 2.0 Benzene - Total Flow (lbmol/hr) 310 Temperature (°F) 120 Pressure (psia) 335 Distillation Column Number of stages 15 Feed stage 8 Reflux Ratio 1.2 Cyclohexane recovery 99.99 mole % in bottoms Condenser Pressure 200 psia Reboiler Pressure 210 psia Feed Preheater Outlet Temperature 300 °F Outlet Pressure 330 psia Reactor Stoichiometry Benzene + 3H2 Cyclohexane Conversion 99.8% of benzene Outlet temperature 400°F Pressure drop 15psi Flash Tank Temperature 120°F Pressure drop 5psi Purge Stream Purge rate is 8% of vapor recycle stream Liquid Split 70% of liquid stream goes to distillation column The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. Matbal-001H Revised: Nov 7, 2012 3 Aspen HYSYS Solution 4. 4.01. Start Aspen HYSYS V8.0, select New on the Start Page to start a new simulation. 4.02. Create a component list. In the Component Lists folder, select the Add button to create a new HYSYS component list. 4.03. Define components. Use the Find button to select the following components: Hydrogen, Nitrogen, Methane, Benzene, and Cyclohexane. 4.04. Select a property package. In the Fluid Packages folder in the navigation pane click Add. Select SRK as the property package. Matbal-001H Revised: Nov 7, 2012 4 4.05. We must now specify the reaction involved in this process. Go to Reactions folder in the navigation pane and click Add to add a reaction set. 4.06. In Reactions | Set-1 select Add Reaction. Select the Hysys radio button and select Conversion. Then click Add Reaction. Once a new reaction (Rxn-1) can be seen on the reaction set page, close the Reactions window shown below. 4.07. Double click on Rxn-1 to define the reaction. In the reaction property window, add components Benzene, Hydrogen, and Cyclohexane to the Stoichiometry Info grid. Enter -1, -3, and 1, respectively, for stoichiometry coefficients. In the Basis grid select Benzene as Base Component, Overall for Rxn Phase, 99.8 for Co, and 0 for both C1 and C2. This indicates that the reaction will convert 99.8% of benzene regardless of temperature. Close this window when complete. Matbal-001H Revised: Nov 7, 2012 5 4.08. Attach this reaction set to a fluid package by clicking the Add to FP button. Select Basis-1 and click Add Set to Fluid Package. The reaction set should now be ready. 4.09. We are now ready to enter the simulation environment. Click the Simulation button in the bottom left of the screen. Matbal-001H Revised: Nov 7, 2012 6 4.10. First we will place a Mixer and a Heater block onto the flowsheet. 4.11. Double click on the mixer (MIX-100) to open the mixer property window. Create 2 inlet streams: H2FEED, BZFEED; and 1 outlet stream: ToPreHeat. Matbal-001H Revised: Nov 7, 2012 7 4.12. Go to the Worksheet tab to define streams H2FEED and BZFEED. First we will define the Conditions of each stream. For H2FEED, enter a Temperature of 120°F, a Pressure of 335 psia, and a Molar Flow of 310 lbmole/hr. For BZFEED, enter a Temperature of 100°F, a Pressure of 15 psia, and a Molar Flow of 100 lbmole/hr. Note that you can change the global unit set to Field if the units are different than those displayed below. Matbal-001H Revised: Nov 7, 2012 8 4.13. Next we will define the Composition of the two feed streams. In the Worksheet tab go to the Composition form. Enter the compositions shown below. You will notice that after inputting the composition, the mixer will successfully solve for all properties. 4.14. Double click on the heater block (E-100) to configure the heater. Select stream ToPreHeat as the inlet and create an outlet stream called R-IN. Add an energy stream called PreHeatQ. Matbal-001H Revised: Nov 7, 2012 9 4.15. Go to the Worksheet tab and specify the outlet stream R-IN temperature and pressure. Enter 300°F for Temperature and 330 psia for Pressure. Matbal-001H Revised: Nov 7, 2012 10 4.16. The flowsheet should look like the following at this point. 4.17. We will now add a Conversion Reactor to the flowsheet. Press F12 on the keyboard to open the UnitOps window. Select the Reactors radio button and select Conversion Reactor. Press Add. 4.18. In the Conversion Reactor property window, select the inlet stream to be R-IN, and create a Liquid Outlet called LIQ and a Vapour Outlet called VAP. In the Parameters form, enter a Delta P of 15 psi. Matbal-001H Revised: Nov 7, 2012 11 Matbal-001H Revised: Nov 7, 2012 12 4.19. In the Reactions tab, select Set-1 for Reaction Set. Notice that when the reactor solves, the contents of the reactor are entirely in the vapor phase, therefore there is no liquid flow leaving the bottom of the reactor. Matbal-001H Revised: Nov 7, 2012 13 4.20. Next we will add a Cooler to the main flowsheet to cool down the vapor stream leaving the reactor. 4.21. Double click on the cooler block (E-101) to open the cooler property window. Select VAP as the inlet stream and create an outlet stream called COOL. Also add an energy stream called COOLQ. In the Parameters form enter a Delta P of 5 psi. Matbal-001H Revised: Nov 7, 2012 14 4.22. Go to the Worksheet tab to specify the outlet stream temperature. Enter 120°F for the Temperature of stream COOL. The cooler will solve. Matbal-001H Revised: Nov 7, 2012 15 4.23. We will now add a Separator block to separate the vapor and liquid phases of streamCOOL. From the model palette add a Separator to the flowsheet. 4.24. Double click on the separator block (V-100). Select COOL as the inlet stream and create liquid and vapor outlet streams called LIQ1 and VAP1. The separator should solve. Matbal-001H Revised: Nov 7, 2012 16 4.25. The flowsheet should now look like the following. 4.26. We will now add 2 Tee blocks, 1 for each of the separator outlet streams. One tee will be used to purge a portion of the vapor stream to prevent impurities from building up in the system. The other tee will be used to recycle a portion of the liquid back to the mixer and the rest of the liquid will be fed to a distillation column. Matbal-001H Revised: Nov 7, 2012 17 4.27. Double click on the first Tee block (TEE-100). Select stream VAP1 as the inlet, and create 2 outlet streams VAPREC, and PURGE. Matbal-001H Revised: Nov 7, 2012 18 4.28. Go to the Parameters page and enter 0.08 for the Flow Ratio for stream PURGE. 4.29. You can rotate the icon for a block by selecting the icon and clicking the Rotate button in the Flowsheet/Modify tab in the ribbon. Matbal-001H Revised: Nov 7, 2012 19 4.30. Double click the second Tee block (TEE-101). Select LIQ1 for the inlet stream and create 2 outlet streams LIQREC, and ToColumn. 4.31. In the Parameters tab enter a Flow Ratio of 0.7 for stream ToColumn. Matbal-001H Revised: Nov 7, 2012 20 4.32. The flowsheet should now look like the following. (FAQ) Useful Option To Know: Saving Checkpoints Save “checkpoints” as you go. Once you have a working section of the flowsheet, save as a new file name, so you can revert to an earlier checkpoint if the current one becomes too complex to troubleshoot or convergence errors become persistent. Matbal-001H Revised: Nov 7, 2012 21 4.33. We are now ready to connect the recycle streams back to the mixer. On the main flowsheet, add 2 Recycle blocks. Matbal-001H Revised: Nov 7, 2012 22 4.34. Double click on the first recycle block (RCY-1). Select stream VAPREC as the inlet stream and create an outlet stream called VAPToMixer. 4.35. Double click the second recycle block (RCY-2). Select LIQREC as the inlet stream and create an outlet stream called LIQToMixer. Matbal-001H Revised: Nov 7, 2012 23 4.36. Connect the recycle streams back to the mixer. Double click the mixer block (MX-100). On the Design | Connections sheet add LIQToMixer and VAPToMixer as inlet streams. The flowsheet should converge. 4.37. The flowsheet should now look like the following. Matbal-001H Revised: Nov 7, 2012 24 4.38. We are now ready to add the distillation column to the flowsheet. From the Model Palette add a Distillation Column Sub-Flowsheet. 4.39. Double click on the Distillation Column Sub-flowsheet. This will launch the Distillation Column Input Expert. Enter 15 for # Stages and specify ToColumn as inlet stream on stage 8_Main TS. Select Full Reflux for Condenser, create an Ovhd Vapour Outlet stream called Off Gas, create Bottoms Liquid Outlet stream called Bot, and add a Condenser Energy Stream called Cond Q. When finished click Next. Matbal-001H Revised: Nov 7, 2012 25 4.40. On page 2 of the Distillation Column Input Expert keep the default selections for Reboiler Configuration and click Next. Matbal-001H Revised: Nov 7, 2012 26 4.41. On page 3 of the Distillation Column Input Expert enter a condenser pressure of 200 psia and a reboiler pressure of 210 psia. Click Next. 4.42. On page 4 of the Distillation Column Input Expert leave fields for temperature estimates blank and click Next. On the final page of the column expert enter a molar Reflux Ratio of 1.2 and click Done to configure the column. Matbal-001H Revised: Nov 7, 2012 27 4.43. After completing the input for the column expert the Column property window will open. We want to create a design specification in order to ensure that 99.99% of the cyclohexane is recovered in the bottoms stream. Go to the Design | Specs sheet. Click Add and select Column Component Recovery. In the Comp Recovery window specify Stream for Target Type, Bot@COL1 for Draw, 0.9999 for Spec Value, and Cyclohexane for Components. Close this window when finished. Matbal-001H Revised: Nov 7, 2012 28 4.44. Go to the Specs Summary sheet and make sure that the only active specs are Reflux Ratio and Comp Recovery. The column should converge. 4.45. The flowsheet is now complete and should look like the following. Matbal-001H Revised: Nov 7, 2012 29 This flowsheet is now complete. Conclusion 5. This is a simplified process simulation, however you should now have learned the basic skills to create and manipulate a steady state chemical process simulation in Aspen HYSYS V8.0. Copyright 6. Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Matbal-002H Revised: Nov 7, 2012 1 Calculation of Gasoline Additives with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to specify a mixer Learn how to use the spreadsheet in Aspen HYSYS to perform customized calculations 2. Prerequisites Aspen HYSYS V8.0 3. Background Ethyl tert-butyl ether (ETBE) is an oxygenate that is added to gasoline to improve Research Octane Number (RON) and to increase oxygen content. The goal is to have 2.7% oxygen by weight in the final product. The legal limit is that ETBE cannot exceed more than 17% by volume. For simplicity, we use 2,2,4-trimethylpentane to represent gasoline. Since ETBE's molecular weight is 102.18 g/mol, the ETBE in the product stream can be calculated as following: This yields 17.243% of ETBE by weight in the product stream. Given this, the spreadsheet tool can be utilized to target the ETBE feed to achieve the desired oxygen content. In this tutorial we will calculate: For a certain flow rate of gasoline (e.g., 100 kg/hr), how much ETBE should be added to achieve the oxygen content of 2.7% by weight in the blended gasoline. Check whether or not the legal limit of ETBE content is satisfied. A HYSYS spreadsheet is used to perform calculations on each criterion. Both targets should be met in the simulation. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. Matbal-002H Revised: Nov 7, 2012 2 4. Aspen HYSYS Solution 4.01. Start a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select Add. Add 2,2,4-trimethylpentane and ETBE to the component list. 4.03. Define property package. In the Fluid Packages folder select Add. Select Peng-Robinson as the property package. 4.04. Enter the simulation environment by clickingthe Simulation button in the bottom left of the screen. 4.05. Add a Mixer to the flowsheet from the Model Palette. Matbal-002H Revised: Nov 7, 2012 3 4.06. Double click on the mixer (MIX-100). Create two Inlets called ETBE and Gasoline. Create an Outlet called Blend. Matbal-002H Revised: Nov 7, 2012 4 4.07. Define feed streams. Go to the Worksheet tab. For stream ETBE enter a Temperature of 25°C and a Pressure of 1 bar. Leave Mass Flow empty as we will solve for it later. 4.08. In the Composition form under the Worksheet tab, enter a Mole Fraction of 1 for ETBE in the ETBE feed stream. Matbal-002H Revised: Nov 7, 2012 5 4.09. Define gasoline feed stream. In the Conditions form in the Worksheet tab, enter a Temperature of 25°C, a Pressure of 1 bar, and a Mass Flow of 82.76 kg/h. 4.10. In the Composition form enter a Mole Fraction of 1 for 224-Mpentane in the Gasoline stream. The gasoline stream should solve. However. the mixer will not solve because the flow rate of ETBE is still unknown. Matbal-002H Revised: Nov 7, 2012 6 4.11. We will now create a spreadsheet to calculate the target mass flowrate of stream ETBE. Add a Spreadsheet to the flowsheet from the Model Palette. Matbal-002H Revised: Nov 7, 2012 7 4.12. Double click on the spreadsheet (SPRDSHT-1). Go to the Spreadsheet tab and enter the following text in cells A1 and A2. Matbal-002H Revised: Nov 7, 2012 8 4.13. Right click on cell B1 and select Import Variable. Select the following to import the Mass Flow of stream Gasoline to cell B1. Press OK when complete. 4.14. Click cell B2 and enter the following formula: = (B1*0.17243) / (1-0.17243). This will calculate the mass flow rate for stream ETBE. From the background section, we know that in order to reach the oxygen content goal of 2.7%, we will need the gasoline stream to contain 17.243% ETBE by weight. Matbal-002H Revised: Nov 7, 2012 9 4.15. We now wish to export the calculated flow rate in cell B2 to stream ETBE. Right click cell B2 and select Export Formula Result. Make the following selections and click OK when complete. The mixer should now solve. Matbal-002H Revised: Nov 7, 2012 10 4.16. We will now calculate the volume percent of ETBE in the blended stream to make sure that the ETBE content is below the legal limit of 17 volume percent. This can easily be observed in the spreadsheet. In the spreadsheet, enter the following text in cell A4. 4.17. Right click on cell B4 and select Import Variable. Make the following selections to import Master Comp Volume Frac of ETBE in the blended stream. Click OK when complete. Matbal-002H Revised: Nov 7, 2012 11 4.18. The volume fraction of ETBE in the blended stream is 0.1596, which is below the legal limit of 0.17. It is determined that the target flow rate of ETBE to be mixed with this gasoline stream is 17.24 kg/h. Matbal-002H Revised: Nov 7, 2012 12 5. Conclusions For a specified gasoline mass flow rate of 82.76 kg/hr, 17.24 kg/hr of ETBE is needed to achieve 2.7% oxygen content by weight in the final product. Furthermore, after blending, the product does not exceed the legal limit for ETBE of 17% by volume. If gasoline contains a single component, manual calculation should be easy without a simulator. However, real gasoline contains many unknown components and gasoline’s contents vary as feedstock or plant operation conditions change. Therefore, manual calculation becomes very difficult and the use of a simulator such as Aspen HYSYS can be helpful to carry out the calculation. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their re spective companies. Thermodynamics for Chemical Engineers Prop-001H Revised: Nov 16, 2012 1 Generate Ethylene Vapor Pressure Curves with Aspen HYSYS® V8.0 1. Lesson Objectives Generate vapor pressure curves for Ethylene 2. Prerequisites Aspen HYSYS V8.0 Introduction to vapor-liquid equilibrium 3. Background Separation processes involving vapor-liquid equilibrium exploit volatility differences which are indicated by the components’ vapor pressure. Higher vapor pressure means a component is more volatile. Ethylene is an important monomer for polymers and there are many ethylene plants around the world. A vital step in ethylene production is separating it from other compounds and as a result the vapor pressure of ethylene is an important physical property for ethylene production. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement Determine the vapor pressure of ethylene at 5 °C, and its normal boiling point. Also create a plot of vapour pressure versus temperature. Aspen HYSYS Solution 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component List folder select Add. Add Ethylene to the component list. Prop-001H Revised: Nov 16, 2012 2 4.03. Double click on Ethylene to view the pure component properties. Go to the Critical tab. Make a note that the Critical Temperature is 9.2°C and the Normal Boiling Point is -103.8°C. Prop-001H Revised: Nov 16, 2012 3 4.04. Define property methods. Go to the Fluid Packages folder and click Add. Select Peng-Robinson as the property package. 4.05. Move to the simulation environment. Click the Simulation button in the bottom left of the screen. 4.06. Add a Material Stream to the flowsheet. Prop-001H Revised: Nov 16, 2012 4 4.07. Double click on material stream (1). The vapor pressure of liquid is the atmospheric pressure at which a pure liquid boils at a given temperature. The point at which the first drop of liquid begins to boil is called the bubble point, which is found in HYSYS by specifying a vapour fraction of 0. Therefore, we can find the vapor pressure of pure liquid by specifying a temperature and vapour fraction of 0. 4.08. In material stream 1, enter a Vapour Fraction of 0, a Temperature of 5°C, and a Molar Flow of 1 kgmole/h. In the Composition form under the Worksheet tab enter a Mole Fraction of 1 for Ethylene. 4.09. You can see that the Pressure is 45.93 bar. This is equivalent to the vapour pressure of ethylene at this temperature. Next we would like to determine the normal boiling point of ethylene. Instead of specifying temperature, we will specify pressure. Empty the field for temperature and enter a value of 1 bar for Pressure. Prop-001H Revised: Nov 16, 2012 5 4.10. The newly calculated temperature is -104.3°C. This is the boiling temperature of ethylene at a pressure of 1 bar. 4.11. Next we would like to create a plot of vapour pressure versus temperature. First, in the Material Stream 1 window, empty the field for Pressureand enter any Temperature (below critical temperature). This will allow us to vary temperature when we perform a case study. Go to the Case Studies folder in the Navigation Pane and click Add. Prop-001H Revised: Nov 16, 2012 6 4.12. In Case Study 1, click Add to select the variables. Select the Temperature and Pressure of stream 1. In the Independent Variable field enter a Low Bound of -150°C, a High Bound of 0°C, and a Step Size of 10°C. Click Run. Prop-001H Revised: Nov 16, 2012 7 4.13. After running the case study, go to the Plots tab. Here you will see a plot of Pressure vs Temperature. Prop-001H Revised: Nov 16, 2012 8 4.14. Note that by looking at the plot you can verify that at around -104°C the vapour pressure if approximately 1 bar, indicating the normal boiling point. 5. Conclusions As we can see from the generated plot, ethylene is a very volatile component. At 5°C, its vapor pressure is about 45.93 bar. From this analysis, we also see that ethylene’s normal boiling point temperature is about –104 °C. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Prop-003H Revised: Nov 5, 2012 1 Retrieve Pure Component Property Data with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to retrieve property data for pure components in Aspen HYSYS. 2. Prerequisites Aspen HYSYS V8.0 3. Background There are many reasons that we need physical properties of pure components. When we look for a solvent for extractive distillation (a technology that uses a third component, the solvent, to separate two components in a mixture that are difficult to separate directly via distillation), we look for components with normal boiling point temperatures that are higher (but not too much higher) than the components to be separated. For such a case, we need to know the normal boiling point temperatures of candidate solvents during the search. When we look for a solvent for extraction, we need to check the densities of candidate solvents to ensure the two liquid phases formed during extraction have enough differences in density. For the selected solvent, we also need to check its density against the existing liquid phase so that we know which liquid phase is heavier. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement The pre-condition of this example is that 3-methylhexane is now considered a promising candidate solvent for separation of acetone and water. The task is to determine whether the density of 3-methylhexane is different enough from the density of water. We also need to determine which of the two liquid phases formed mainly by these two components is heavier. Prop-003H Revised: Nov 5, 2012 2 Aspen HYSYS Solution 4.01. Create a new case in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select the Add button to add a new component list. Prop-003H Revised: Nov 5, 2012 3 4.03. Enter 3-methylhexane in the Search for box. Aspen HYSYS should display the relevant search results. If the component you are looking for does not appear, you can also use the Filter or Search by drop-down list for different search criteria. Click the < Add button to add the component to the component list. Prop-003H Revised: Nov 5, 2012 4 4.04. To retrieve and view the pure component property data and, double-click the component 3-Mhexane. A new window should appear. 4.05. Go to the Critical tab in the new window. You will see a list of property data in the Base Properties and Critical Properties frames. Note that the Ideal Liquid Density for 3-methylhexane is 690.2 kg/m3. Prop-003H Revised: Nov 5, 2012 5 4.06. In the navigation pane, go to the Components | Component List -1 sheet. Enter water in the Search for box and add the component to the component list. Prop-003H Revised: Nov 5, 2012 6 4.07. Double-click on the component H2O. A new window should appear. Prop-003H Revised: Nov 5, 2012 7 4.08. Go to the Critical tab in the new window. You will see a list of property data in the Base Properties and Critical Properties frames. Note that the Ideal Liquid Density for Water is 998.0 kg/m3. 5. Conclusions The density of 3-methylhexane is around 690.2 kg/m3, which is clearly less than the density of water (998.0 kg/m3). The liquid phase formed mainly by 3-methylhexane should be lighter than the phase formed mainly by water and, thus, the aqueous phase should be at the bottom and the other liquid phase should be at the top. Prop-003H Revised: Nov 5, 2012 8 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Prop-005H Revised: Nov 7, 2012 1 Hypothetical Components and Petroleum Assays with Aspen HYSYS® V8.0 1. Lesson Objectives Create hypothetical components in Aspen HYSYS Characterize a petroleum assay 2. Prerequisites Aspen HYSYS V8.0 3. Background Aspen HYSYS allows you to create non-library or Hypothetical components. These hypothetical components can be pure components, defined mixtures, undefined mixtures, or solids. A wide selection of estimation methods are provided for various Hypo groups to ensure the best representation of behavior for the Hypothetical component in the simulation. In order to accurately model a process containing a crude oil, such as a refinery operation, the oil properties must be defined. It is nearly impossible to determine the exact composition of an oil assay, as there are far too many components in the mixture. This is a situation where hypothetical components are useful. Boiling point measurements of distillate fractions of an assay can be used to characterize the oil properties. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement Create a hypothetical componentgroup in Aspen HYSYS and characterize a petroleum assay to be used in a refinery simulation. Aspen HYSYS Solution 4.01. Start a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select Add. Change the Select field to Hypothetical and enter the Initial and Final Boiling Points for the hypothetical group shown below. Click Generate Hypos when complete. This will generate a group of hypothetical components with estimated properties based on the specified boiling point of each cut. Prop-005H Revised: Nov 7, 2012 2 4.03. Click Add All to add the entire hypothetical group to the component list. Prop-005H Revised: Nov 7, 2012 3 4.04. Define property package. In the Fluid Packages folder select Add. Select Peng-Robinson as the property package. 4.05. Enter the simulation environment by clicking the Simulation button in the bottom left of the screen. Prop-005H Revised: Nov 7, 2012 4 4.06. Add a Material Stream to the flowsheet from the Model Palette. Double click the stream and go to the Composition form under the Worksheet tab. 4.07. You will notice that the mole fractions of all the components are empty. If you would like to assign an oil assay to this stream go to the Petroleum Assay form under the Worksheet tab. Select the option Create New Assay On Stream. Prop-005H Revised: Nov 7, 2012 5 4.08. Click the Petroleum Assay Specifications button. This page allows you to enter assay distillation data or import data from a known oil assay. Prop-005H Revised: Nov 7, 2012 6 4.09. Click the Import From button and select Assay Library to import data from a known assay in the HYSYS assay library. 4.10. Say, for example, that we want to model a refinery process using Bachaquero heavy crude from Venezuela. Scroll down the list of assays and select Bachaquero, Venezuela. Click Import Selected Assay. Prop-005H Revised: Nov 7, 2012 7 4.11. After a few moments the MacroCut Data window will be filled with distillation cut data for Bachaquero heavy crude. 4.12. Click the Calculate Assay button to assign mole fractions to the hypothetical components defined for the stream. Exit the MacroCut Data window and view the Components form of the material stream. Prop-005H Revised: Nov 7, 2012 8 4.13. The composition for the stream is now defined and will model the properties of the selected petroleum assay through the use of hypothetical components. 5. Conclusions This example demonstrates how to create hypothetical components and how to assign a petroleum assay to a stream in order to model the assay properties in a simulation. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-002H Revised: Nov 6, 2012 1 Flash Calculation in Aspen HYSYS® V8.0 1. Lesson Objective Learn how to model a Flash separator and examine different thermodynamic models to see how they compare. Flash blocks in Aspen HYSYS 2. Prerequisites Aspen HYSYS V8.0 3. Problem We want to investigate Vapor-Liquid separation at different pressures, temperatures and compositions. Assume you have a feed with an equimolar binary mixture of ethanol and benzene at 1 bar and 25°C. Examine the following flash conditions using the heater block in Aspen HYSYS. Use Vapor-Liquid as the Valid Phase in the computation. Condition #1 (P-V Flash): At 1 bar and a vapor fraction of 0.5, find the equilibrium temperature and the heat duty. Condition #2 (T-P Flash): At the temperature determined from Condition #1 and a pressure of 1 bar, verify that the flash model results in a vapor fraction of 0.5 at equilibrium. Condition #3 (T-V Flash): At the temperature of Condition #1, and a vapor fraction of 0.5, verify that the flash model results in an equilibrium pressure of 1 bar. Condition #4 (P-Q Flash): At 1 bar and with the heat duty determined from Condition #1, verify that the temperature and vapor fraction are consistent with previous conditions. Condition #5 (T-Q Flash): At the temperature and heat duty determined from Condition #1, verify that the pressure and vapor fraction are consistent with previous conditions. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Aspen HYSYS Solution: 4.01. Start Aspen HYSYS V8.0. Select New to start a new simulation. 4.02. Create a component list. In the Component Lists folder select Add. Select Ethanol and Benzene. Thermo-002H Revised: Nov 6, 2012 2 4.03. Create a fluid package. In the Fluid Packages folder select Add, and select NRTL as the property package. 4.04. Go to the simulation environment. Click the Simulation button in the bottom left of the screen. 4.05. Place a Heater block onto the flowsheet from the Model Palette. Thermo-002H Revised: Nov 6, 2012 3 4.06. Double click the Heater to open the property window. Create an Inlet stream called FEED, an Outlet stream called OUT, and an Energy stream called Q. 4.07. Specify conditions of FEED stream. Go to the Worksheet tab and enter a Temperature of 25°C, a Pressure of 1 bar (100 kPa), and a Molar flow of 1 kgmole/h. Also enter Mole Fractions of 0.5 for each component on the Composition form. Thermo-002H Revised: Nov 6, 2012 4 4.08. Condition #1 Compute the temperature to get 0.5 vapor fraction at 1 bar. In the Conditions form under Worksheet, enter a Vapour Fraction of 0.5 and a Pressure of 1 bar (100 kPa) for stream OUT. The heater will automatically solve and you will see that the calculated temperature is 67.03°C. 4.09. Condition #2 Compute vapor fraction at 1 bar and at the temperature obtained in Condition #1. Clear the field for Vapour Fraction for stream OUT, then enter a Pressure of 1 bar (100 kPa) and a Temperature of 67.03°C. In order to be able to enter a temperature, you must first empty the entry field for Vapour Fraction. This is done by clicking the entry field and pressing delete on the keyboard. Once a Temperature is entered, the Vapour Fraction will solve. Thermo-002H Revised: Nov 6, 2012 5 4.10. Condition #3 Compute pressure at the temperature obtained in Condition #1 with 0.5 vapor fraction. Delete the value in the Pressure field and enter a Vapour Fraction of 0.5. The pressure should solve. Thermo-002H Revised: Nov 6, 2012 6 4.11. Condition #4 Compute temperature and vapor fraction at 1 bar and using the heat duty obtained in Condition #1. Empty the fields for Temperature and Vapour Fraction in stream OUT. In stream OUT enter a Pressure of 1 bar. In stream Q, enter a Heat Flow of 2.363e004 kJ/h. The Temperature of 67.03°C and Vapour Fraction of .500 are consistent with Condition #1. 4.12. Condition #5 Compute pressure and vapor fraction at the temperature and heat duty obtained in Condition #1.In stream OUT, empty the field for Pressure. Enter a Temperature of 67.03°C. The Pressure and Vapor Fraction should be the same as Condition #1. Thermo-002H Revised: Nov 6, 2012 7 5. Conclusion You have gone through the five flash methods which are most common in Aspen HYSYS. Here is a brief summary. Flash Method T (C) P (bar) V (-) Q (MJ/hr) P-V Flash 67.03 1 0.5 23.63 T-P Flash 67.03 1 0.5099 23.98 T-V Flash 67.03 1 0.5 23.63 P-Q Flash (or P-H) 67.03 1 0.5 23.63 T-Q Flash (or T-H) 67.03 1 0.5 23.63 Specified Computed Feed Condition: ETHANOL/BEZENE (Equimolar mixture) at 1 bar and 25 Celsius. Thermo-002H Revised: Nov 6, 2012 8 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-003H Revised: Nov 6, 2012 1 Steam Tables in Aspen HYSYS® V8.0 1. Objective Learn how to access Steam Tables in Aspen HYSYS, and how to interpret the Steam Table data. 2. Prerequisites Aspen HYSYS V8.0 3. Background Aspen HYSYS offers 2 types of Steam Tables Properties Methods: Property Method Name Models (Steam Tables) Note ASME Steam ASME 1967 The ASME Steam property method uses the: 1967 International Association for Properties of Water and Steam (IAPWS, http://www.iapws.org) correlations for thermodynamic properties STEAM-TA method is made up of different correlations covering different regions of the P-T space. These correlations do not provide continuity at the boundaries, which can lead to convergence problems and predict wrong trends. NBS Steam NBS 1984 The NBS Steam property methods uses the: 1984 International Association for Properties of Water and Steam (IAPWS, http://www.iapws.org) correlations for thermodynamic properties Use the NBS Steam property method for pure water and steam with temperature ranges of 273.15 K to 2000 K. The maximum pressure is over 10000 bar. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. http://www.iapws.org/ http://www.iapws.org/ Thermo-003H Revised: Nov 6, 2012 2 4. Problem Using Aspen HYSYS, we want to calculate saturated steam properties from 100°C to 300°C. We would like to create a table that displays mass enthalpy, mass entropy, pressure, and density. Aspen HYSYS Solution: 4.01. Start Aspen HYSYS V8.0. Select New to start a new simulation. 4.02. Create a component list. In the Component Lists folder, select Add. Add Water to the component list. 4.03. Create a fluid package. In the Fluid Packages folder, select Add. Select NBS Steam as the property package. 4.04. Go to the simulation environment. Thermo-003H Revised: Nov 6, 2012 3 4.05. Add a material stream to the flowsheet from the Model Palette. Double click on the stream to open the property window. Rename this stream STEAM and enter a Mole Fraction of 1 for water. 4.06. In the navigation pane, go to Stream Analysis and click on the dropdown arrow next to Add and select Property Table. In the Select Process Stream window that appears, select STEAM and press OK. 4.07. Next, double click on Property Table-1 to open the property window. Under Independent Variables select Temperature as Variable 1. Enter a Lower Bound of 100°C and an Upper Bound of 300°C. Enter 100 for # of Increments. Select Vapour Fraction for Variable 2 and select State for Mode. Enter a value of 1 for State Values. We are going to be varying the temperature while holding the vapour fraction constant at 1. Thermo-003H Revised: Nov 6, 2012 4 4.08. We must now define the dependent properties that we are interested in viewing results for. Go to the Dep. Prop form under the Design tab. Select Add. Here we will add Mass Enthalpy, Mass Entropy, Pressure, and Mass Density. Thermo-003H Revised: Nov 6, 2012 5 4.09. Click Calculate to generate the property table. Results can be viewed in the Performance tab of the property table window. Thermo-003H Revised: Nov 6, 2012 6 5. Conclusion After completing this exercise you should now be familiar with how to access and interpret thermodynamic properties for steam using Aspen HYSYS. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-004H Revised: Nov 6, 2012 1 Heat of Vaporization with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to calculate heat of vaporization using the heater block in Aspen HYSYS Understand the impact of heat of vaporization on distillation 2. Prerequisites Aspen HYSYS V8.0 3. Background The driving force for distillation is energy. The most energy consuming part of a distillation column is the vaporization of material in the reboiler to cause vapor to flow from the bottom of the column to the top of the column. Heat of vaporization determines the amount of energy required. Therefore, it is important to know the heat of vaporization of various species during solvent selection. With everything else equal, we should select a component with lower heat of vaporization so that we can achieve the same degree of separation with less energy. This example contains three isolated heater blocks. Each heater block is used to calculate the heat of vaporization for a pure component. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. Thermo-004H Revised: Nov 6, 2012 2 4. Aspen HYSYS Solution: 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder, select Add. Select Water, 3-methylhexane, and 1,1,2-trichloroethane. 4.03. Create a fluid package. In the Fluid Packages folder, select Add. Select UNIQUAC as the property package and select RK as the Vapour Model. 4.04. Enter the simulation environment. Thermo-004H Revised: Nov 6, 2012 3 4.05. Add three separate Heater blocks to the flowsheet. 4.06. Double click on E-100 to open the property window.This first heater will vaporize a stream of pure water. Create an Inlet stream called Feed-Water, an Outlet stream called Water-Out, and an Energy stream called Q-Water. Thermo-004H Revised: Nov 6, 2012 4 4.07. Go to the Worksheet tab. Specify the feed stream to be at a Pressure of 100 kPa, a Vapour Fraction of 0, and with a Molar Flow of 1 kgmole/h. In the Composition form under the Worksheet tab, enter a Mole Fraction of 1 for Water in the feed stream. Lastly, we must specify the outlet pressure and the outlet vapour fraction. Enter 100 kPa for Pressure, and 1 for Vapour Fraction of the Water-Out stream. The heater should solve. Make note of the Heat Flow of the energy stream Q-Water. 4.08. We will now repeat this process for heaters E-101 and E-102. E-101 will vaporize 3-methylhexane and E- 102 will vaporize 1,1,2-trichloroethane. 4.09. Double click on E-101. Create an Inlet stream called Feed-3MH, an Outlet stream called 3MH-Out, and an Energy stream called Q-3MH. Thermo-004H Revised: Nov 6, 2012 5 4.10. In the Worksheet tab, for the feed stream enter a Vapour Fraction of 0, a Molar Flow of 1 kgmole/h, and a Pressure of 100 kPa. In the Composition form, enter a Mole Fraction of 1 for 3-methylhexane in the feed stream. Lastly specify the outlet conditions of 100 kPa for Pressure and a Vapour Fraction of 1. Make note of the Heat Flow for the energy stream. Thermo-004H Revised: Nov 6, 2012 6 4.11. Double click E-102. Create an Inlet stream called Feed-1,1,2, an Outlet stream called 1,1,2-Out, and an Energy stream called Q-1,1,2. 4.12. In the Worksheet tab, for the feed stream enter a Vapour Fraction of 0, a Molar Flow of 1 kgmole/h, and a Pressure of 100 kPa. In the Composition form, enter a Mole Fraction of 1 for 1,1,2- trichloroethane in the feed stream. Lastly specify the outlet conditions of 100 kPa for Pressure and a Vapour Fraction of 1. Note the Heat Flow of the energy stream. Thermo-004H Revised: Nov 6, 2012 7 5. Conclusions Although water has small molecular weight, its heat of vaporization is large. Heat of vaporization for water is about 18% higher than that of 1,1,2-trichloroethane and about 30% higher than that of 3-methylhexane. Of the three options, 3-methylhexane has to lowest heat of vaporization and would require the least amount of energy as a solvent in a distillation. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Therm-005H Revised: Nov 6, 2012 1 Simulation of Steam Engine with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to simulate a steam engine with Aspen HYSYS Learn how to specify pumps, heaters, coolers, expanders 2. Prerequisites Aspen HYSYS V8.0 Introductory thermodynamics 3. Background A steam engine consists of the following steps: Water is pumped into a boiler using a pump. Water is vaporized in a boiler and becomes high temperature and pressure steam. Steam flows through a turbine and does work. The pressure and temperature go down during this step. The steam is also partially condensed. The steam is further cooled to be condensed completely. Then, it is fed to the pump mentioned in the first step to be re-used. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Aspen HYSYS Solution 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder, select Add. Add Water to the component list. Therm-005H Revised: Nov 6, 2012 2 4.03. Create a fluid package. In the Fluid Packages folder, select Add. Select NBS Steam as the property package. 4.04. Go to the simulation environment by clicking the Simulation button in the bottom left of the screen. In the Home ribbon, select EuroSI as the Unit Set. 4.05. Enter the simulation environment. Add a Heater, a Cooler, a Pump and an Expander as shown in the flowsheet. Therm-005H Revised: Nov 6, 2012 3 4.06. Double click the pump (P-100) to open the pump specification window. Create an Inlet stream called Liq-Water, an Outlet stream called ToBoiler, and an Energy stream called Q-Pump. 4.07. In the Worksheet tab, specify an outlet Pressure of 1.2 bar. Therm-005H Revised: Nov 6, 2012 4 4.08. Double click the heater (E-100). Select ToBoiler as the Inlet stream, create an Outlet stream called HPSteam (high pressure steam), and create an Energy stream called Q-Heat. 4.09. In the Worksheet tab, specify an outlet Pressure of 40 bar, and a Temperature of 460°C. Therm-005H Revised: Nov 6, 2012 5 4.10. Double click the expander (K-100). Select HPSteam as the Inlet stream, create an Outlet stream called LPSteam, and create an Energy stream called Q-Expand. Therm-005H Revised: Nov 6, 2012 6 4.11. In the Worksheet tab, specify an outlet Pressure of 1 bar. Therm-005H Revised: Nov 6, 2012 7 4.12. Double click the cooler (E-101). Select an Inlet stream of LPSteam, an Outlet stream of Liq-Water, and create an Energy stream called Q-Cool. Therm-005H Revised: Nov 6, 2012 8 4.13. In the Worksheet tab, specify an outlet Vapour Fraction of 0 and a Pressure of 1 bar. 4.14. The flowsheet is now ready to solve. All that is left to do is to specify the composition and flowrate of a stream within the loop. Double click on stream Liq-Water and specify a Mole Fraction of 1 for Water and a Mass Flow if 10,000 kg/h. Therm-005H Revised: Nov 6, 2012 9 Therm-005H Revised: Nov 6, 2012 10 4.15. The flowsheet should now solve. 5. Conclusions The steam engine system can be simulated using Aspen HYSYS. This flowsheet clearly shows where energy is being input to the system and where energy is being released. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-006H Revised: Nov 6, 2012 1 Illustration of Refrigeration with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to specify compressors, heaters, and valves in Aspen HYSYS Understanda refrigeration loop 2. Prerequisites Aspen HYSYS V8.0 Introductory thermodynamics 3. Background In a typical refrigeration system, the refrigerant starts at room temperature and ambient pressure. It is compressed, which increases the refrigerant’s temperature and pressure so it is a superheated vapor. The refrigerant is cooled by air with a fan so that it is close to room temperature. At this point, its pressure remains high and the refrigerant has been condensed to a liquid. Then, the refrigerant is allowed to expand through an expansion valve. Its pressure decreases abruptly, causing flash evaporation, which reduces the refrigerant’s temperature significantly. The very cold refrigerant can then cool a fluid passed across a heat exchanger (e.g., air in an air conditioner). Of course, for an AC unit to work, the air that is used to cool down the super-heated refrigerant must be air outside of the room; the air that is cooled by the cold refrigerant is the air inside the room. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Aspen HYSYS Solution Problem Statement Determine the cooling capacity of 300 kgmole/h of CFH2-CF3 when allowed to expand from 10 bar to 1 bar. Thermo-006H Revised: Nov 6, 2012 2 Aspen HYSYS Solution 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select Add. Add 1,1,1,2-tetrafluoroethane to the component list. 4.03. Create a fluid package. In the Fluid Packages folder, select Add. Select NRTL as the property package. 4.04. Move to the simulation environment. Click the Simulation button in the bottom left of the screen. In the Home ribbon, select EuroSi as the Unit Set. 4.05. Add a Compressor, a Cooler, a Heater, and a Valve to the main flowsheet. Thermo-006H Revised: Nov 6, 2012 3 4.06. Double click on the compressor (K-100). Create an Inlet stream called Vapor, an Outlet stream called SuperHeat-Vapor, and an Energy stream called Q-Comp. Thermo-006H Revised: Nov 6, 2012 4 4.07. In the Worksheet tab, specify an outlet Pressure of 10 bar. Thermo-006H Revised: Nov 6, 2012 5 4.08. Double click the Cooler (E-100). Select SuperHeat-Vapor as the Inlet stream, create an Outlet stream called Liquid, and create an Energy stream called Q-Cool. 4.09. In the Worksheet tab, specify an outlet Temperature of 30°C. In the Parameters form under the Design tab, enter a Delta P of 0. Thermo-006H Revised: Nov 6, 2012 6 4.10. Double click the valve (VLV-100). Select stream Liquid as the Inlet stream and create an Outlet stream called LowP. Thermo-006H Revised: Nov 6, 2012 7 4.11. In the Worksheet tab specify an outlet Pressure of 1 bar. Thermo-006H Revised: Nov 6, 2012 8 4.12. Double click on the heater (E-101). Select stream LowP as the Inlet stream, select stream Vapor as the Outlet stream, and create an Energy stream called Q-Heat. 4.13. In the Worksheet tab, specify an outlet Temperature of 25°C. In the Parameters form under the Design tab, specify a Delta P of 0. Thermo-006H Revised: Nov 6, 2012 9 We must now specify the molar flowrate and composition of the refrigerant. Double click any stream, for example stream Liquid. Enter a Molar Flow of 300 kgmole/h. In the Composition form specify a Mole Fraction of 1 for the refrigerant. Thermo-006H Revised: Nov 6, 2012 10 4.14. The flowsheet will now solve. Thermo-006H Revised: Nov 6, 2012 11 4.15. Check results. To view the cooling capacity of this refrigeration loop, double click energy stream Q-Heat. The stream is removing 1.26e006 kcal/h, or approximately 350 kcal/sec. 5. Conclusions Refrigeration is a process where heat moves from a colder location to a hotter one using external work (e.g., a compressor). We know that vaporization of a liquid takes heat. If there is no external heat available, the heat will come from the liquid itself by reducing its own temperature. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-007H Revised: Nov 6, 2012 1 Maximum Fill up in Propane Tanks with Aspen HYSYS® V8.0 Using a Spreadsheet 1. Lesson Objectives How to calculate the maximum liquid level in propane tanks How to access stream variables in Aspen HYSYS How to configure a heater block How to use the Spreadsheet tool to perform customized calculations 2. Prerequisites Aspen HYSYS V8.0 3. Background When a propane tank is filled at 25°C, we need to leave enough volume for liquid propane expansion due to an increase in temperature. The hottest weather ever recorded is about 58°C. In real life practices, propane tanks are only filled up to 80-85% of the tank volume. Why? We know that propane expands when it is heated up. However, why 80-85%? We can answer this question by using a simple flash calculation in Aspen HYSYS. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement Propane tanks are filled at 25°C with liquefied propane. These tanks will be stored and used in an environment at 1 bar and ambient temperature. How much, in terms of volume %, can each tank be filled up to? Thermo-007H Revised: Nov 6, 2012 2 Aspen HYSYS Solution 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select Add. Add Propane to the component list. 4.03. Create a fluid package. In the Fluid Packagers folder, select Add. Select Peng-Robinson as the property package. 4.04. Go to the simulation environment. Click the Simulation button in the bottom left of the screen. 4.05. Add a Heater to the flowsheet. Thermo-007H Revised: Nov 6, 2012 3 4.06. Double click on the heater (E-100). Create an Inlet stream, an Outlet stream, and an Energy stream, named 1, 2, and Q, respectively. Thermo-007H Revised: Nov 6, 2012 4 4.07. Define feed stream. Go to the Worksheet tab. For the feed stream, enter a Vapour Fraction of 1, a Temperature of 25°C, and a Molar Flow of 1 kgmole/h. In the Composition form, enter 1 for Mole Fraction of propane. Thermo-007H Revised: Nov 6, 2012 5 4.08. Specify outlet conditions. For the outlet stream, enter a Vapour Fraction of 0, and a Temperature of 58°C. The heater should solve. 4.09. Add a Spreadsheet to the flowsheet to calculate the maximum percent to fill the propane tank to allow for expansion when heated. Thermo-007H Revised: Nov 6, 2012 6 4.10. Double click the spreadsheet (SPRDSHT-1). Go to the Spreadsheet tab and enter the following in cells A1, A2, and A3. Thermo-007H Revised: Nov 6, 2012 7 4.11.Now we will link flowsheet variables to the spreadsheet. Right click on cell B1 and select Import Variable. Make the following selections to import the Molar Density of stream 1. Click OK when complete. 4.12. Right click on cell B2 and select Import Variable to import the Molar Density of stream 2. Make the following selections and click OK. Thermo-007H Revised: Nov 6, 2012 8 4.13. The spreadsheet should now look like the following. 4.14. Next, click cell B3 and enter “=(B2/B1)*100”. This divides the molar density at 58°C by the molar density at 25°C. The resulting number is the percentage that a propane tank should be filled at 25°C to allow for thermal expansion up to a temperature of 58°C. 4.15. The maximum fill % of propane at 25°C is 87.86%, as seen in the spreadsheet. Thermo-007H Revised: Nov 6, 2012 9 5. Conclusions The calculation shows that the maximum fill up is 87.8% if the ambient temperature doesn’t exceed 58 °C. To accommodate special cases, typically, propane tanks are filled up to 80-85%. After completing this exercise you should be familiar with how to create a spreadsheet to perform custom calculations. It is important to note that, in real life, the content in a filled propane tank is typically a mixture instead of pure propane. In addition to propane, the mixture also has a few other light components such as methane and ethane. Therefore, to carry out calculations for a real project, we need to know the compositions of the mixture we are dealing with. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-013H Revised: Nov 7, 2012 1 Generate PT Envelope with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to generate PT envelopes in Aspen HYSYS 2. Prerequisites Aspen HSYSY V8.0 3. Background It is very important to know the phase conditions of a mixture at a given temperature and pressure. For example, the phase conditions of a fluid in a heat exchanger have an impact on the heat transfer rate. Formation of bubbles (vapor phase) in inlet streams can also be very damaging to pumps. The phase conditions of a fluid in a pipe can impact pipeline calculations. The PT envelope for a given mixture provides a complete picture of phase conditions for a given mixture. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Aspen HYSYS Solution 4.01. Start Aspen HYSYS V8.0 and start a new simulation. 4.02. Create a component list. In the Component Lists folder select Add. Add Ethane and n-Pentane to the component list. Thermo-013H Revised: Nov 7, 2012 2 4.03. Define property package. In the Fluid Packages folder select Add. Select Peng-Robinson as the property package. 4.04. Go to the simulation environment by clicking the Simulation button in the bottom left of the screen. 4.05. Add a Material Stream to the flowsheet. To create a PT Envelope we must perform a Stream Analysis, and in order to perform a Stream Analysis we need a material stream. Thermo-013H Revised: Nov 7, 2012 3 4.06. Double click the material stream (1). Enter a Molar Flow of 100 kg/h. In the Composition form enter Mass Fractions of 0.5 for each component. 4.07. Right click on the stream and select Create Stream Analysis | Envelope. Thermo-013H Revised: Nov 7, 2012 4 4.08. In the Envelope window, go to the Performance tab. Here you will see a PT Envelope. Note that you can change the Envelope type using the radio buttons in the bottom right corner of the window. On the graph, the blue line represents the dew point and the red line represents the bubble point. The area between the lines represents the 2-phase region. Thermo-013H Revised: Nov 7, 2012 5 5. Conclusions With the PT envelope of a mixture, we can determine its phase conditions for a given temperature and pressure. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied with or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-014H Revised: Nov 7, 2012 1 Retrograde Behavior Illustrated with Aspen HYSYS® V8.0 1. Lesson Objectives Observe retrograde behavior 2. Prerequisites Aspen HYSYS V8.0 Completion of teaching module Thermo-013 3. Background For a mixture, the amount of liquid (liquid fraction) increases as pressure increases at constant temperature. However, in the retrograde region near the critical region, we may see some interesting behavior—vapor fraction increases as pressure increases (at constant temperature). Many mixtures have retrograde behavior near the critical region. In this example, we will examine the retrograde behavior using a binary mixture of ethane and pentane. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement Retrograde behavior can be observed in the mixture of ethane and pentane. In Aspen HYSYS, use PT Envelope to determine the critical region of the mixture. Then, use a Property Table to examine the retrograde behavior near the critical region. Thermo-014H Revised: Nov 7, 2012 2 Aspen HYSYS Solution 4.01. Open the file titled Thermo-14H_Retrograde_Behavrior_Start.hsc. This is identical to the file that was created in lesson Thermo-013H_PT_Envelope. 4.02. In the PT Envelope that appears in the Performance tab of the Envelope window, notice that there is a region near the critical point where the vapor fraction will increase as pressure increases while temperature is held constant. Thermo-014H Revised: Nov 7, 2012 3 4.03. We can demonstrate this behavior by creating a property table in HYSYS. In the Stream Analysis folder in the Navigation Pane, click the dropdown arrow next to Add and select Property Table. Select stream 1 and click OK. Thermo-014H Revised: Nov 7, 2012 4 4.04. Double click Property Table-1. Select Temperature for Variable 1 and select State for Mode. Enter a State value of 115°C. SelectPressure for Variable 2 and Incremental for Mode. Enter a Lower Bound of 60 bar, an Upper Bound of 69 bar, and a # of Increments of 20. 4.05. In the Dep. Prop form under the Design tab click Add. Select Vapour Fraction and click OK. Thermo-014H Revised: Nov 7, 2012 5 4.06. Click Calculate. Once complete, go to the Performance tab. Here you can view the results in either table or plot form. Go to Plots and select View Plot. 4.07. From the plot you can clearly see the region where increasing the pressure will cause the vapour fraction to increase. 5. Conclusions For the binary mixture of ethane and pentane (50% each on mass basis), we observed that vapor fraction increases from 0.701457 to 1 as pressure increases from 65.22 bar to 66.78 bar, which is a retrograde behavior. This retrograde behavior can be a source of multiple solutions to process simulation. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be Thermo-014H Revised: Nov 7, 2012 6 liable to you for damages, including any loss of profits, lost savings, or other incidental or consequential damages arising out of the use of the information contained in, or the digital files supplied w ith or for use with, this work. This work and its contents are provided for educational purposes only. AspenTech®, aspenONE®, and the Aspen leaf logo, are trademarks of Aspen Technology, Inc.. Brands and product names mentioned in this documentation are trademarks or service marks of their respective companies. Thermo-019H Revised: Nov 7, 2012 1 Remove Hydrogen from Methane, Ethylene and Ethane with Aspen HYSYS® V8.0 1. Lesson Objectives Learn how to remove bulk of hydrogen using a cooler and a vapor liquid separator Learn how to use adjust block and spreadsheets 2. Prerequisites Aspen HYSYS V8.0 Introduction to vapor-liquid equilibrium 3. Background In an ethylene plant, we have a feed stream containing hydrogen, methane, ethylene, and ethane . Before this stream can be fed to the demethanizer, hydrogen must be removed so the volumetric flow is less, which decreases the required size for the demethanizer column. Because hydrogen has a much higher vapor pressure than the other components, one or more flash drums can be used for hydrogen removal. The examples presented are solely intended to illustrate specific concepts and principles. They may not reflect an industrial application or real situation. 4. Problem Statement and Aspen HYSYS Solution Problem Statement The feed stream is a combination of 6,306 lb/hr of hydrogen, 29,458 lb/hr of methane, 26,049 lb/hr of ethylene, and 5,671 lb/hr of ethane. The mole fraction of hydrogen in the feed stream is greater than 0.51, indicating a large volume of hydrogen in the feed stream. There are two goals for this section of the process: After bulk of hydrogen is removed, the stream contains less than 0.02 mole fraction of hydrogen Loss of ethylene to the hydrogen stream should be less than 1% Thermo-019H Revised: Nov 7, 2012 2 Aspen HYSYS Solution 4.01. Create a new simulation in Aspen HYSYS V8.0. 4.02. Create a component list. In the Component Lists folder select Add. Add Hydrogen, Methane, Ethylene, and Ethane to the component list. 4.03. Define property package. In the Fluid Packages folder select Add. Select Peng-Robinson as the property package. 4.04. Go to the simulation environment. Click the Simulation button in the bottom left corner of the screen. 4.05. Add a Cooler block to the flowsheet from the Model Palette. Thermo-019H Revised: Nov 7, 2012 3 4.06. Double click the cooler (E-100). Create an Inlet stream called Feed, an Outlet stream called ToSep, and an Energy stream called Q-Cool. Thermo-019H Revised: Nov 7, 2012 4 4.07. In the Parameters form, enter a Delta P of 0, and a Duty of 0 kcal/h. We will create an adjust block to vary the duty to reach the desired specifications. Thermo-019H Revised: Nov 7, 2012 5 4.08. Define feed stream. Go to the Worksheet tab. Enter a Temperature of -90°F (-67.78°C), and a Pressure of 475 psia (32.75 bar). 4.09. Define composition. Go to the Composition form and enter the following Mass Flow rates in kg/h. Thermo-019H Revised: Nov 7, 2012 6 4.10. Add a Separator to the flowsheet from the Model Palette. 4.11. Double click the separator (V-100). Select stream ToSep as the Inlet stream, and create Outlet streams called Vap and Liq. Thermo-019H Revised: Nov 7, 2012 7 4.12. Go to the Worksheet tab to view the separation results. You can see that the liquid stream has a flowrate of 0. We must now add an adjust block and a spreadsheet to find the cooler duty required to limit the loss of ethylene to the vapor stream to less than 1%. Thermo-019H Revised: Nov 7, 2012 8 4.13. Add a Spreadsheet to the flowsheet from the Model Palette. 4.14. Double click on the spreadsheet (SPRDSHT-1). In the Spreadsheet tab enter “Ethylene flow in Feed” in cell A1, and “Ethylene flow in Liq stream” in cell A2. Right click on cell B1 and select Import Variable. Select the Master Comp Molar Flow (Ethylene) in the Feed stream. Right click cell B2 and select Import Variable. Select the Master Comp Molar Flow (Ethylene) in the Liq stream. Thermo-019H Revised: Nov 7, 2012 9 4.15. Enter the text “Fraction Ethylene Lost” in cell A3. In cell B3 enter the following formula: = (B1-B2)/B1. 4.16. You can see that right now we are losing 100% of the Ethylene to the vapor stream. We will now add an adjust block to vary the cooler duty in order to limit the fraction lost to under 0.01. Add an Adjust block to the flowsheet from the Model Palette. Thermo-019H Revised: Nov 7, 2012 10 4.17. Double click on the adjust block (ADJ-1). Specify the Adjusted Variable to be the Duty of cooler block E- 100. Specify the Target Variable to be cell B3 of SPRDSHT-1. Enter a Specified Target Value of 0.01. Thermo-019H Revised: Nov 7, 2012 11 4.18. In the Parameters tab enter a Step Size of 1e+005 kcal/h and change the Maximum Iterations to 100. Click Start to begin calculations. Thermo-019H Revised: Nov 7, 2012 12 4.19. The fraction of ethylene lost in the vapor stream will now be less than 1%. We must also make sure that the Mole Fraction of Hydrogen in the liquid stream is less than 0.02. Double click the Liq stream and go to the Composition form under the Worksheet tab. 4.20. The Mole Fraction of hydrogen in the liquid stream is 0.0172, which is less than the specified value of 0.02. Thermo-019H Revised: Nov 7, 2012 13 5. Conclusions The vapor pressure of hydrogen is much higher (6,600 times higher than methane at -150 °C) than the vapor pressures of the other components in the feed stream. We used the adjust block and a spreadsheet to determine a good value for the heat duty of the cooler block to remove the bulk of hydrogen from the feed stream through a separator block. 6. Copyright Copyright © 2012 by Aspen Technology, Inc. (“AspenTech”). All rights reserved. This work may not be reproduced or distributed in any form or by any means without the prior written consent of AspenTech. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS WORK and assumes no liability for any errors or omissions. In no event will AspenTech be liable to you for damages,
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