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Problem Statement: How do I add properties for a component that is available in a newer version of Aspen Plus into an older one? | Solution: In the newer version, include the databases where you want to look for the components in Components/Enterprise Database:
Add the components of interest:
Go to Tools/Retrieve parameter results:
The forms in Properties/Parameters will be filled:
Note that all of the values retrieved come from a Database (in this case the NIST-TRC database):
In order to have these values available in earlier versions of the software where either the database or the properties were not available you need to convert the values to ?user? values. To do this just copy and paste the same values:
Repeat these steps for all pure component and binary interaction parameters.
Export the file as an input file by going to file/Export/ save as type input file.
Use the following procedure to create a bkp file from an input file:
1. Launch Aspen Simulation Engine from Start/Programs/AspenTech/Process Modeling Vxx /Aspen Plus/Aspen Plus Simulation Engine.
2. Browse to the folder containing your input file using DOS accepted commands. Type cd foldername to select a folder, and cd.. to go back to the previous folder.
3. Type aspen nameoffile.inp /mmbackup.
This procedure will run the input file and create a backup file. Note that the name of the file must contain only alphanumeric characters (so you may need to rename your file). It is important to note also that after typing nameoffile.inp you must include a space and then type /mmbackup.
The bkp file created will be the same version of the Aspen Simulation Engine you used to create it.
Keywords: Databank, database, property
References: None |
Problem Statement: The energy demand for the Rate Based DGA model for CO2 seems too low. During a case study in which I investigated several lean loadings of the solvent with focus on the specific energy demand of the desorber (kJ/kg CO2 separated), I observed that with higher lean loading the energy demand decreases significantly. There is no optimum which is abnormal. The second thing is that the energy demand itsself is to low: you can get a demand of around 2000 kJ/kg CO2. If this were right, everybody would uses DGA as a solvent for CO2 removal.
Cause
We found the interaction parameters of the DGA model were over-fit. This might bring convergence problems and incorrect results at high loading. In addition, the previous DGA model released three years ago only used the VLE data of the ternary DGA-H2O-CO2 system to fit the parameters which resulted in a very strong temperature dependence of the interaction parameters.
To solve this problem, we have updated the DGA model with the methodology we applied to the MDEA model (Zhang and Chen (2011)).
We fit the VLE and heat of absorption data simultaneously. The absorption heat data is helpful to determine correct temperature dependence of the interaction parameters. We also checked the NMR speciation data to confirm the concentration of true species in the liquid phase. The new DGA model should provide more reliable predictions. | Solution: In the attached file, we have updated the DGA model using the methodology we applied to the MDEA model (Zhang and Chen (2011). The backup file will run in V7.2 and higher.
We fit the VLE and heat of absorption data simultaneously. The absorption heat data is helpful to determine correct temperature dependence of the interaction parameters. We also checked the NMR speciation data to confirm the concentration of true species in the liquid phase. The new DGA model should provide more reliable predictions.
Please see the Figures in the attached zip file.
Now the model can converge at atmospheric pressures (in the attached bkp file, it converges at 1 atm).
To aid convergence, a few things can be helpful.
1. Provide temperature estimates.
For example, in the attached bkp file, we provide temperature estimates for stages 1 (320 K) and 16 (285 K). We cannot converge the case if we don't provide temperature estimates.
2. Start from an initial (easy to converge) case, then converge it gradually to the final (difficult to converge) case. That means we can use the results of the easy case as the initial values for the difficult case to help convergence.
Generally, it is difficult to converge at high CO2 loading (large flow rate of CO2 into the absorber) but easy at low CO2 loading (small flow rate of CO2 into the absorber).
For example, we may find it is difficult to converge the a case with a high CO2 loading at 60 atm even if we provide temperature estimates. Therefore, we may change the flow rate of gas into the absorber from 900 kmol/hr to 100 kmol/hr which converges easily. After that, we use those results as initial values, increase the flow rate to 300 kmol/hr and converge it, then 500 kmol/hr, 700 kmol/hr? finally, we will converge at 900 kmol/hr.
Keywords: None
References: : CQ00435434 |
Problem Statement: How to determine the power of a stream against the reference temperature and pressure conditions that the user specifies? | Solution: The power of the stream against the reference temperature and pressure can be calculated as a difference between the enthalpy for a mixture in current stream conditions and enthalpy for the mixture in reference conditions specified by the user.
These calculations can be done in the calculator block and user has the option to specify which stream this value will be calculated, as you can see in the attached example. Below you can see calculator block specification:
In calculator block user can see the following equation: POWER = HMX – HMXREF.
HMX is a property specified using Property Sets and it is Enthalpy for a mixture in default temperature and pressure (default for this property = stream condition).
To specify a second value for this equation: HMXREF, the user needs to define in Property Sets not only a property: Enthalpy for a mixture (HMX), but also reference temperature and pressure. It can be done in the Qualifiers tab and the user need to enter Phase (in example: Total) and
Keywords:
References: temperature and pressure. Note that specified conditions will be used only if System box is unchecked, as you can see in a screenshot below. |
Problem Statement: The hydrolysis of calcium carbide produces acetylene and calcium hydroxide. This reaction involves chemical components in solid, liquid and gas phases.
How to model this reactor properly? | Solution: The hydrolysis of calcium carbide is given as
CaC2 + 2 H2O → C2H2 + Ca(OH)2
This reaction is the basis for the production of acetylene. Involved in this reaction, calcium carbide (CaC2) and calcium hydroxide (Ca(OH)2) are solid. Water (H2O) is typically in liquid state. Acetylene (C2H2) is gas.
To set up this reaction system in AspenPlus, the following steps should be followed,
1) On Setup | Specifications, select MIXCISLD for Stream Class. The solids will be in the Conventional (CISOLID) substream so that their properties are calculated with the appropriate solid models.
2) Select components as shown on the screen shot; both calcium hydroxide and calcium carbide should be identified as solids.
3) On Properties | Specifications, select SOLIDS as Property Method.
4) Build the process flowsheet using the RGibbs reactor to model the reactor.
5) In the reactor, specify the products calcium hydroxide and remaining calcium carbide as PureSolid. For reactions involving solids, it is a good practice to explicitly specify all of the possible products.
6) Enter calcium carbide and recycle calcium hydroxide feeds to the reactor in CISOLID substream.
A running case using unrealistic feed rates is given as attachment.
Keywords: acetylene, calcium carbide, calcium hydroxide.
References: None |
Problem Statement: User Property Model example: liquid vapor pressure subroutine with regression of the user model parameters. | Solution: The attached example illustrates how to implement a user property model in Aspen Plus, in this case for the calculation of the liquid vapor pressure (PL). Each user property model should include a principal subroutine that calculates and returns the desired physical properties. Since the principal subroutines are called directly by the appropriate physical property monitors, they have a fixed name and argument list structure. They also contain model-specific parameters that are passed to the user subroutine during calculations. Property user models are documented in the User Models Guide Chapter 6.
The user subroutine in this example returns the liquid vapor pressure (PL) and takes the values of the model-specific parameter called PL0UA to perform the calculations. In the example the coefficients of the T-dependent parameter (PL0UA) are regressed from experimental data coming from the NIST. For simplicity the model implements a version of the extended Antoine equation reduced to 5 coefficients.
In order to make the user model active in the corresponding property routes, PL0USR should be selected:
Please note also highlighted in the screen shot above the model-specific parameter for liquid vapor pressure PL0UA. This parameter should be added as follows:
Keywords: User Physical Property Models, Fortran Subroutines, Regression.
References: None |
Problem Statement: Sometimes there are multiple standard statements corresponding to one Batch Plus operation. For example, Charge operation might correspond to Visual Inspection, Weighing the Material and Charge. In such case, what modification can the user do to prevent the page break in Microsoft Word to break in between of those consecutive statements? | Solution: Clear the allow rows to break across pages box in Table | Properties | Row dialog, for each table in each standard statement.
If you highlight rows of a table and check Keep With Next in the Format | Paragraph... dialog, Word will keep those sets of multiple rows on the same page.
So, if you edit each standard statement, highlight the rows in the statement and check this paragraph format property for a group of rows you want to keep together.....Word will make sure that the group of rows are never split between pages.
Do not turn on Keep With Next for the last row of your standard statements (or the last row in the part of a standard statement whose rows you don't want broken across pages), so you don't run the risk of trying to force too many rows to stay together.
How can you tell which rows (or paragraphs) have this property set? A: When you check Tools | Options | View | Formatting Marks | Paragragh (or just click the backwards P button in the Standard toolbar), a little square does shows up at the bottom left end of the row.
Keywords: Operating Instruction
References: None |
Problem Statement: Can Not Create New Project. | Solution: Check the following:
1. Is the working directory read-only? If it is, remove the read only status, if you still have problem go to next step.
2. Under Aspen Batch Plus install directory (by default, it is C:\Program files\AspenTech\Aspen Batch Plus 2004.1), there is a bin folder which store all the binary files. Make sure this is folder and all the files underneath it are not read-only, if you still have problem go to next step.
3. Sort the files in the bin folder by type. Look for .tmp files. Those are template files which Aspen Batch Plus uses to create new project and step. There are 4 of them prior to 2004, after 2005, there are 5 of them. If you do not have those, please either copy those from your colleagues machine, or call Aspentech support to get those. Those files are MS Access files, they stay the same between full install major releases. We have seen IS department in certain companies uses cleanup utility to delete files with tmp extension. If this is the case, please notify your IS department that, it is very dangerous practice to delete files from Program Files folder.
Development is looking into the possibility of changing the file extension from tmp to something less confusing, it is undetermined if this enhancement will be in version 2006.
Keywords: Create
Project
tmp
References: None |
Problem Statement: Why is the molecular weight of my stream containing a polymer or oligomer component calculated as if it only has one unit of monomer? | Solution: The Average MW displayed in the Stream Results is calculated from the parameter MW. The actual value can be reported by adding a Property Set with the property TRUEMW.
This will report the correct molecular weight considering the number of segments in the oligomer or polymer.
Keywords: segment, monomer
References: None |
Problem Statement: How does the Energy Map button in the ConSep(Shown below) model work and when can we use this feature?
Is this option also available in the ConSep block in the new interface for versions V8.X? | Solution: The Energy Map button allows the user to select how to calculate the enthalpy of the lumped feed when component mapping is defined. It affects the quality of the lumped feed, and therefore the design results.
The quality of the lumped feed is defined as:
quality= (feed_enthalpy - v_enthalpy)/(l_enthalpy - v_enthalpy)
There are four options available for mapping the stream:
If the user selects Preserve Feed Quality (q), then the temperature and enthalpy of the lumped feed will be re-calculated so that the quality of the original feed is preserved.
If the user selects Preserve Feed Enthalpy (energy/mole), then the quality of the lumped feed will be re-calculated so that the enthalpy of the original feed is preserved.
If the user selects Saturated Liquid Feed (q=1), or Saturated Vapor Feed (q=0), then the enthalpy of the lumped feed will be re-calculated based on q = 1 or q = 0.
The Energy Map button is not accessible to the user in V8.0 or later versions because the UI was redesigned and the ConSep block was changed into a built-in Aspen Plus block.
Keywords: Energy Map, ConSep, Conceptual design
References: None |
Problem Statement: Very large file crashes when opening in some machines. | Solution: It is possible that there are not enough resources.
By default Windows does not allocate enough resources, so some registry settings have to be modified. Here's a link to the article from Microsoft support:
http://support.microsoft.com/?kbid=126962
Here are the steps to fix the problem (BE SURE TO REBOOT AFTER CHANGING THESE SETTINGS):
To correct this problem, increase the size of the desktop heap:
1. Run Registry Editor (Regedt32.exe).
2. From the HKEY_LOCAL_MACHINE subtree, go to the following key:
\System\CurrentControlSet\Control\Session Manager\SubSystems Select the Windows value.
3. From the Edit menu, choose String.
4. Increase the SharedSection parameter.
For Windows NT:
SharedSection specifies the system and desktop heaps using the following format:
SharedSection=xxxx,yyyy
Add ,256 or ,512 after the yyyy number.
For Windows 2000, Windows XP, and Windows Server 2003:
SharedSection uses the following format to specify the system and desktop heaps:
SharedSection=xxxx,yyyy,zzzz
For 32-bit operating systems, increase the yyyy value to 12288; Increase the zzzz value to 1024.
For 64-bit operating systems, increase the yyyy value to 20480; Increase the zzzz value to 1024.
Keywords: None
References: None |
Problem Statement: What Intellichem Synthesis Version Does Aspen Batch Plus Intellichem Interface Support? | Solution: Version 3.60 and 3.65.
The Interface format AspenTech and Intellichem has agreed upon is that
For recipes, it is BatchML
For materials, Aspen Batch Plus uses Intellichem's format.
AspenTech has been issuing Aspen Batch Plus/Intellichem interface according to this format from version 12.1. Intellichem supports this format with versions 3.60 and 3.65. Versions 4.0 and 5.0 of Intellichem Synthesis do not currently support the intermediate format used for transfer to Batch Plus. Therefore, Batch Plus Intellichem interface cannot be used yet with versions 4.0 and 5.0.
We will update this document once Intellichem finishes their updates.
Keywords: intellichem
interface
References: None |
Problem Statement: The outlet stream mole flow is in lbmol/hr. Instead, I want mol/sec. My input for the stream mole flow is in mol/min, but I don't see a way to change the outlet stream mole flow units. | Solution: Follow the below steps to change the units of the outlet stream mole flow. This will change the units for ALL stream and block output.
1. Navigate to Data/Data Browser/ Setup/ Units-Sets, and double click Units-Sets folder.
2. Click New button to create a new set.
3. Enter an ID (Set1) and click OK.
4. Click yes to make Set1 the global unit set.
5. Confirm that ENG is entered in the Copy from field.
6. Change the Mole flow to mol/sec.
7. Reinitialize and run your model.
You will get the Mole flow reported on mol/sec.
Keywords: Outlet stream units, units, customize, mole flow.
References: None |
Problem Statement: I have a simulation that is not using any external subroutine, however, after running I see the following error and the simulation stops.
*** SEVERE ERROR (FPFNDI.1) COULD NOT RESOLVE USER OR IN-LINE FORTRAN SUBROUTINE(S): SUBROUTINE ZZSENS IS MISSING
How can I solve this error? | Solution: This error happens in two situations:
i) If there is Fortran syntax inside a calculator block, design spec or a sensitivity analysis that cannot be interpreted by the engine, or
ii) If the program is forced to write all inline code in an external subroutine to be compiled.
The engine creates simple statements for calculator blocks, design specs or sensitivity analysis. This normally does not require you to have a Fortran compiler and linker and the program is able to interpret this code. If this error appears:
1) In the Simulation environment, go to Setup | Calculation Options | System
2) Select Interpret all inline Fortran statements at execution time for the Fortran compilation options.
Keywords: Fortran subroutine, design spec, calculator block, sensitivity analysis.
References: None |
Problem Statement: How can a user access pre-defined petroleum Property Sets in Aspen Plus? | Solution: When opening a new simulation, select to open the Petroleum with Metric Units or Petroleum with English Units templates.
The templates can also be imported into an existing Aspen Plus simulation by going to File | Import. The templates can be found in the following directory:
C:\Program Files (x86)\AspenTech\Aspen Plus V8.8\GUI\Templates\Refinery
Make sure that the file type Templates (*.apt) is selected.
Keywords: Aspen Plus, Petroleum, Property, Sets
References: None |
Problem Statement: How can I delete a molecular structure in the Pure Components dialog after it had been accidentally imported from a *.mol file? | Solution: Since this is a situation rarely encountered, there is no Undo or Delete key available. The Delete button in the Pure Components dialog will actually delete the entire record of a given component.
To delete the molecular structure only, use Notepad (or any other editor of your choice) and create an emtpy *.mol file. For example:
empty.mol (size: 0 bytes)
Importing this file will delete the old structure.
Note: In Route Selection (Chemist View), there are dedicated buttons for importing and deleting the structure of any new intermediate.
Keywords: pure component
molecular structure
mol file
References: None |
Problem Statement: How do I change the color of the unit operations in Aspen Plus? | Solution: There is no way to change the color of the unit operations that are already added to a simulation. To change the color of the icon you need to create your own icon library.
To create an icon library in Aspen Plus, go to the Library menu and click New. This will display a window to enter the library name and the path you want to save your library in and click on Create:
After entering the library name and the path go to the Library menu again and select the name of the newly created library. Click on the library name and select the option Edit. Add the unit operation you wish to change by dragging it from the model library in Aspen Plus to the new sheet. The following window will show up:
Click on next, enter a category. Click on next again (leave all the default options) and finally click on Finish. This will add the selected block to the new category you created:
Right click on the newly added icon and select the option Edit Current Icon. This will take you to the Icon Editor window:
Click on the icon to select it and then move to the left side and select the color you want your icon to have. Choose the color you want and the icons borders will be changed to the color you selected:
After changing the color to the icon go to the Icon menu and select Update Icon.
Go back to the Process Flowsheet Window and on the Model Library tab you will see your created Library. Open the libray, select the icon you just created and add it to the PFD:
If you want the icon to be filled in, select one of the filled in options on the model libraries and do the same procedure:
Keywords: Model library, icon, icon editor
References: None |
Problem Statement: What operations use use or change Particle Size Distributions (PSD) in Batch Plus? | Solution: Most of the secondary operations use or manipulate the particle size distribution:
Mix
Classify (separation)
Screen (separation)
Granulate (produce solid)
Mill (reduce size)
Pulverize (reduce size)
High-shear-Granulate (produce solid)
Extrude (produce solid)
Roller-Compact (produce solid)
Also, the following unit operations will produce a cake in which users can specify the PSD:
Filter
Filter-In-Place
Centrifuge
Keywords:
References: None |
Problem Statement: How to navigate through the MS Access results database to find the material components (pure components and pre-defined mixtures) that make up the contents of a vessel at the end of each operation | Solution: When you open up the Microsoft Access database from the Results Menu/MS Access, there are 45 tables to choose from, and each one contains cross-refrences to one or more other tables.
To find the material components of a vessel at the end of an operation:
Start with EquipmentContents table. Within the EquipmentContents table, find the operation of interest in the OperationName column. This column lists all of the operations in the step. Within that same row, make note of the EquipmentID number and the ContentsID number.
Go to the EquipmentSummary table to see what piece of equipment the EquipmentID references. This will be the equipment that appears in the column BPTag on the same line as the noted EquipmentID number.
Open the ThermodynamicPhase table and cross reference the ContentsID with one or more PhaseID's. The type of phase (gas, liquid 1, etc.) is listed under the Phase column. This table also lists the mass, mole, and volume fraction that each phase comprises. For exampe, if PhaseID=67, Phase=liquid 1 and Mole Fraction=0.75, then the first (or only) liquid phase in this vessel makes up 75 mole percent of the entire contents.
Go to the PhaseComponents table and match up the PhaseID with one or more ComponentID's This table also lists mass, mole and volume fractions. In this case it is the fraction that each component makes up in that particular phase. For example, it may tell that ComponentID 10065 makes up 50% by weight of the gas phase.
To find what material each ComponentID represents, open the PureComponents table and reference the MaterialID's (MaterialID=ComponentID) with the MaterialName.
Keywords: Equipment Contents, MS Access, Results, EquipmentContents, EquipmentID, ContentsID, EquipmentSummary, ThermodynamicPhase, PhaseID, PhaseComponents, ComponentID, Pure Components, MaterialID, MaterialName
References: None |
Problem Statement: I want to define a component in an electrolyte simulation which is currently not available from the Aspenplus database. I know that I can setup these components as a molecular solute and non-water solvent. I would like to know how Aspen Plus distinguishes between those two types and which parameter changes are required for indicating a molecular solute to a solvent? | Solution: In Aspen Plus, solutes are those components which are defined as Henry's components. Therefore, if the ENRTL property method that the user has defined also has a HENRY-COMP ID associated with it, then the components defined for that HENRY-COMP ID will be treated as a solute. Everything else will be treated as a solvent.
Three types of molecular components may be present in an electrolyte system: solvents, molecular solutes, and electrolytes. As a result of electrolyteSolution chemistry, ions, salts, and nonvolatile molecular solutes may be present as additional true species. These components are defined as:
Ø Solvent: Water is the solvent for aqueous electrolyte systems. For mixed-solvent electrolyte systems, there are other solvent components in addition to water.
Ø Molecular solutes: Are molecular species, other than solvent compounds, that exist in the liquid phase in molecular form. All molecular solutes are treated with Henry's law. They are often supercritical components.
Ø Electrolytes: Are also molecular species. However, strong electrolytes dissociate completely to ionic species in the liquid phase. Undissociated weak electrolytes can be solvent components or molecular solutes.
Ø Ions: Are nonvolatile ionic species that exist only in the liquid phase.
Ø Salts: Are nonvolatile molecular species that exist as solids.
Keywords: Solute, solvent, electrolyte
References: None |
Problem Statement: When using a sentence in the new help, there are many results not relevant. How do I search for a specific topic in the new help? | Solution: Starting in V8.8, the Aspen Plus and all the products from the aspenONE suite of products help was redesigned to discover more topics and obtain more relevant results from the search. The help is divided in Contents and Index tab and the Search feature.
· The Contents tab displays a list of the topics included in Help. Click an expand icon closed book icon to open a list of topics within that book. Click a topic icon topic icon to open a topic.
· The Index tab displays an alphabetical list of the keywords attached to the topics. Type a keyword to search the list. Select a keyword to display the topic.
· The Search feature will perform a search in the full text of the help. Type your query in the search box at the upper right of the help window and press Enter or click the search button:
When typing a search query:
· If you type multiple separate words, the query will show all topics containing any of those words, e.g:
· If you type a phrase in quotes, the query will show topics containing those words adjacent to one another, e.g:
· If you type words with a + between them, the query will show topics containing all of these words.
Keywords: Aspen Plus online help
References: None |
Problem Statement: How do I use Turbo Start to make Aspen Plus start more quickly? | Solution: Turbo Start is an option introduced in V8.8 to improve start-up performance. It can be enabled on the File | Options | Files tab. Turbo Start pre-loads part of Aspen Plus. When you run Aspen Plus, having it pre-loaded allows Aspen Plus to start very quickly. The pre-loaded version of Aspen Plus does not consume tokens, but it does consume some memory resources.
The turbo-start option starts a memory-resident Aspen Plus User Interface session (running as a service) when you start the computer. When you request Aspen Plus by clicking a file or going through the start menu it attaches to the running process. The engine gets started when you run a model (and it only takes a few seconds - the User Interface is the limiting step by far).
The acceleration influences every start of Aspen Plus except switching from one case to another from within the product (starting in 8.6, the User Interface does not shut down when switching files). When you start Aspen Plus another instance of Turbo Start fires up the in the background, waiting for you to need it… so it will make it faster to open your 2nd, 3rd, 4th case etc.
The biggest benefit is for the frequent user because they start Aspen Plus the most times per week and are more likely to run multiple sessions. For others, the tax of a memory resident process they use infrequently may be less of a bargain.
There is a penalty for the first-time start of any process, but not shutting down the computer does not make that go away completely. As you work with other programs the system may release previously loaded (but currently unused) modules from memory to make room for new content.
Keywords: None
References: None |
Problem Statement: How to copy customized APED from Aspen Plus V7.1 to Aspen Plus V7.2 | Solution: You can use Aspen Properties Database Manager to accomplish this task. The program is located under: Start | Programs | AspenTech | Process Modeling V7.1 | Aspen Properties.
After starting the program, right click mouse on Aspen Physical Properties Databases and select All Tasks, Backup DataBase and provide information pertaining to your customized APED database. Make note of the location of backed up file.
On V7.2, again use Aspen Properties Database Manager and right click mouse on the Aspen Physical Properties Databases, select All Tasks, Restore DataBase and provide information pertaining to the database you backed up.
Keywords: Customized
Database
APED
Restore
Backup
Physical Properties
References: None |
Problem Statement: How is the IN USE bar displayed on the Batch Plus schedule? | Solution: The Schedule View in Batch Plus will show a cross hatched bar with the words IN USE if material is added to equipment and additional operations are performed in the same step.
For example, an IN USE bar will appear for Tank A if you charge reactants in Tank A, perform operations in Tank B, then perform operations in Tank A again.
The IN USE bar will not be displayed if no further operations are performed in the same vessel, even if vessel contents are present.
Keywords:
References: None |
Problem Statement: Is it possible to use a physical property monitor (PPMON_xxx) in a user property model subroutine? | Solution: CALUPP and other physical property monitors (detailed in chapter 3) should not be called from user property subroutines. Doing so may result in recursive function calls which may overwrite variables (such as those in Common blocks) used in the first call, which that call may still need. This will lead to unpredictable results. If you need to do this, contact AspenTech Support for a workaround.
Keywords: None
References: : CQ00703843 |
Problem Statement: I have more than one version of Microsoft Excel installed on my computer. When I use a Calculator Block, can I select the version of Microsoft Excel that the calculator blocks uses? | Solution: When using Aspen Plus it is not possible to select a specific version of Microsoft excel if you have more than one version installed on your computer. In these situations, Aspen Plus invokes the last version of Microsoft Excel that was installed.
TheSolution would be to have either:
i) Only one version of Microsoft Excel installed or,
ii) If the version that the user requires was not the last one installed, uninstall Microsoft Office and re-install it, this way you are forcing that version to be installed last.
Keywords: Calculator block, Microsoft Excel
References: None |
Problem Statement: For many pure components, DIPPR parameters are available from the Batch Plus databanks to calculate the liquid phase density as a function of temperature. For water, Aspen Batch Plus does not provide these DIPPR coefficients. How is the density of pure water calculated? | Solution: In the absence of DIPPR coefficients, Aspen Batch Plus uses the Rackett model to calculate the liquid phase density. A value for the Rackett parameter of pure water is available from the Aspen Batch Plus databanks; hence, the liquid phase density of pure water is calculated using the Rackett model.
Keywords: Density
Water
DIPPR
Rackett
References: None |
Problem Statement: How do I know if the CPA parameters are in the databanks? I cannot see them in the Aspen Properties Enterprise Database (APED) Manager or retrieve them using Retrieve Parameter Results into the User Interface | Solution: The CPA parameters are proprietary and cannot be seen in the user interface. In order to determine if the parameters are available, you can view the status of values.
After retrieving the CPA parameters, you can go to the Methods | Parameters | Results form to view the status of pure and binary parameters. Listed below are status values for CPA parameters for H2O/CO2/CH4O.
Pure parameters, CPAAT, CPAAU, CPAAV, CPAM, CPAPC, CPATC:
CPA binary parameters, CPAKIJ and CPAVIJ:
Keywords:
References: None |
Problem Statement: What is the difference between using an RStoic and RGibbs for combustion? | Solution: You can check the Generate combustion reactions on the Setup | Combustion sheet of an RStoic to have it automatically generate combustion reactions. Full combustion is assumed when this option is specified: all carbon is converted to carbon dioxide and all hydrogen to water. The nitrogen combustion product may be specified as either NO or NO2. SeeSolution 107515 for more details.
RGibbs uses Gibbs free energy minimization to calculate the equilibrium. RGibbs does not require that you specify the reaction stoichiometry. Full combustion is NOT assumed.
In the attached example file that can be opened in Aspen Plus V8.4 and higher, there are the two RStoic blocks fromSolution 107515 plus an RGibbs block to model the same reactor. In addition, there is another set of RStoic and RGibbs blocks that models what happens when a larger amount of Oxygen is fed to the reactor.. One lists all of the combustion reactions (BURNER) and the other automatically generates the reactions (BURNERC). The results are the same.
The RStoic block BURNER has the reactions specified and complete conversion is specified for each.
The RStoic block BURNERC uses the Combust option and the results are the same as BURNER.
The RGibbs block BURNERG has the same feed as BURNER and BURNERC, but it predicts the outlet compositions. In the product, there is some CO in addition to the CO2.
In RGibbs block BURNERG2 and RStoic block BURNERC2, the amount of O2 in the feed has been increased. In the Gibbs reactor, there is a smaller amount of CO in the product than in the product of BURNERG.
Keywords: None
References: None |
Problem Statement: What files in a Batch Plus project directory should not be deleted? | Solution: Files with extensions of .prj, .eqm, .mtl and .stp should not be deleted. If any of these files is deleted, the project may not open.
To clean up a project directory (deleting output or intermediate files), use the Cleanup files feature under Tools.
Keywords: file, files, cleanup, delete, file extension, file management
References: None |
Problem Statement: How to use custom models in the Aspen Batch Process Developer Models library to describe batch operations in your process. | Solution: The Custom model can be used to represent a batch operation that cannot be adequately described by any of the existing models in the Aspen Batch Process Developer Models library.
The Custom model may be used to represent any of the following phenomena:
A? Addition of one or more feed streams
A? Creation and consumption of components through reaction
A? Redistribution of components among the phases present
A? Heat effect and external heat loss
A? Energy exchange with a utility
A? Transfer of the contents of the main equipment unit to several destination vessels
Keywords: custom, batch operations
References: None |
Problem Statement: In V7.1, the help lists 6 option codes for GMENRTL; however, there are only 3 on the form. Are the others available; how should they be used? | Solution: The electrolyte NRTL activity coefficient model (GMENRTL) has three option codes. The electrolyte NRTL Gibbs free energy model (GMXENRTL) has six option codes. The electrolyte NRTL enthalpy model (HMXENRTL) has seven option codes. These option codes can affect the performance of these models.
Option Codes for Electrolyte NRTL Activity Coefficient Model (GMENRTL)
Option code 1. The user can use this option code to specify the choice of the default values of pair parameters for water/solute and solvent/solute; the solute represents a cation/anion pair. The value (1) sets the default values to zero and the value (3) sets the default values for water/solute to (8,-4) and for solvent/solute to (10,-2). The value (3) is the default choice of the option code.
Option code 2. No longer used.
Option code 3. Only the single value (1) should be used to indicate the solvent/solvent binary parameters obtained from NRTL parameters.
Option Codes for Electrolyte NRTL Gibbs Free Energy Model (GMXENRTL)
Option code 1. Use this option code to specify the default values of pair parameters for water/solute and solvent/solute; the solute represents a cation/anion pair. The value (1) sets the default values to zero and the value (3) sets the default values for water/solute to (8,-4) and for solvent/solute to (10,-2). The value (3) is the default choice of the option code.
Option code 2. Use this option code to specify the vapor phase equation-of-state (EOS) model used for the liquid Gibbs free energy calculation. The value (0) sets the ideal gas EOS model and the value (1) sets the HF EOS model. The value (0) is the default.
Option code 3. Always leave this option code set to the value (1) to use the solvent/solvent binary parameters obtained from NRTL parameters.
Option code 4. Not used.
Option code 5. Use this option code to specify how the pure vapor phase fugacity coefficient (PHIV) is calculated. The value (0) sets PHIV = 1 (ideal gas law), the value (1) specifies using Redlich-Kwong equation of state, and the value (3) specifies using Hayden-O?Connell equation of state. The value (0) is the default.
Option code 6. Use this option code to specify the method for handling Henry components and multiple solvents. The value (0) sets the pure liquid Gibbs free energy to that calculated by aqueous infinite dilution heat capacity (only water as solvent) and the value (1) sets the pure liquid Gibbs free energy for Henry components using Henry?s law. Use value (1) when there are multiple solvents. The value (0) is the default.
Option Codes for Electrolyte NRTL Enthalpy Model (HMXENRTL)
Option code 1. Use this option code to specify the default values of pair parameters for water/solute and solvent/solute; the solute represents a cation/anion pair. The value (1) sets the default values to zero and the value (3) sets the default values for water/solute to (8,-4) and for solvent/solute to (10,-2). The value (3) is the default choice of the option code.
Option code 2. Use this option code to specify the vapor phase equation-of-state (EOS) model used for the liquid enthalpy calculation. The value (0) sets the ideal gas EOS model and the value (1) sets the HF EOS model. The value (0) is the default.
Option code 3. Always leave this option code set to the value (1) to use the solvent/solvent binary parameters obtained from NRTL parameters.
Option code 4. Not used.
Option code 5. Use this option code to specify how the vapor phase enthalpy departure (DHV) is calculated. The value (0) sets DHV = 0, the value (1) specifies using Redlich-Kwong equation of state, and the value (3) specifies using Hayden-O?Connell equation of state. The value (0) is the default.
Option code 6. Not used.
Option code 7. Use this option code to specify the method for handling Henry components and multiple solvents. The value (0) sets the pure liquid enthalpy to that calculated by aqueous infinite dilution heat capacity (only water as solvent) and the value (1) sets the pure liquid enthalpy for Henry components using Henry?s law. Use value (1) when there are multiple solvents. The value (0) is the default.
Keywords: None
References: None |
Problem Statement: What is the correct way to specify the number of valves or caps on a tray? | Solution: The number of passes on a tray is entered on the Tray Rating | Setup | Specs sheet. A tray is made of panels. It can have 1 to 4 passes. The convention in Aspen Plus is
No. of passes
Panel Type
one-pass
A
two-pass
A,B
three-pass
A,B,C
four-pass
A,B,C,D
Refer to the Aspen Plus online help for single-pass and multi-pass trays in the Unit Operation Models
Keywords: TPSAR, valve tray rating
References: for details.
You enter the number of caps or valves (Nvalves) for each type of panel, not the number of valves on a tray on the Tray Rating | Setup | Layout sheet. Aspen Plus knows the number of panels and their types once the number of passes (Npass) is selected.
If you don't enter values for Nvalves, you can specify the valve density, which is defined as the number of valves per unit area. Use the on-line help for more information. |
Problem Statement: How do I define the Actual Volume flow of a mixture as a design spec flowsheet variable? | Solution: Firstly, add the volume flow (VOLFLMX) as a property set (Properties / Prop-Sets).
This property set can be specified as the Design Spec flowsheet variable as follows:
Keywords:
References: None |
Problem Statement: The vent of the vessel is closed. Why do I still get emission? How can I turn the emission off for vessel which has a closed vent? | Solution: For historical reason, emission calculation does not take into consideration of vessel's vent status. There is plan to make this determination of vent status to be automatic - that is, if vent is closed, no emission comes out of the vessel.
Meanwhile, you can turn the emission off for any operation by going to the operation dialog, Model tab. There is a check box called No vapor emissions for this operation. This will turn the emission off for all the vessels involved with the operation.
Keywords: vent
emission
References: None |
Problem Statement: I could not have multiple copies of the same form open. I was looking at the profiles of a distillation column. I had selected profiles, and then the hydraulic profile tab. I then went back out to the flowsheet, re-selected the block, selected results, then profile and the compositions. Instead of opening a second tab, it just replaced the hydraulic profile tab. In V7.2 and earlier, you can have more than one instance of an form open; however, this is not possible in V7.3.2 and later. What is the rationale for this change? | Solution: When we tested the new user interface we found performance dropping quickly as the user accumulated forms. Every time you clicked a block it would bring up the input form. Customers would end up opening many copies of the same form. Since the presentation of multiple forms is not very good many customers were not even aware they had multiple instances of a form open. Also, it is inconvenient to keep closing forms.
The design was changed so the system checks if a form is already open. When the user requests the form again (for example by clicking on a block) the system will take them to the existing instance of the form. You can have multiple different forms for the same block open at the same time. For example, for RadFrac, you can have Results, Profiles, and Stream Results open at the same time, but you cannot have the TPFQ profiles and Composition profiles showing at the same time. We hard-coded a few special exceptions for this.
The consequence is that you cannot see two tab sheets of the same form at the same time. We did not think that this is a big price to pay given the benefits. For results profiles, it is relatively easy to launch plots and have multiple plots on the screen concurrently. It is much easier to understand plotted results anyway.
In general, if you want to view two different results forms for the same unit operation at the same time, you can open the 2nd form from the navigation pane, and select “Open in a new tab” from the navigation pane RMB menu.
Now you can see multiple sheets.
Keywords: None
References: None |
Problem Statement: Aspen Batch Plus is installed on Citrix enviroment. Have problem open Aspen Batch Plus projects by multiple users. | Solution: The following files on Citrix need to be modified:
bpv01.bp - this file is located under Aspen Batch Plus install directory, bin folder
All the language template files - located under Aspen Batch Plus install directory, Language folder.
By modifing the above files to READ-ONLY, multiple users can access citrix Batch Plus simultaneously. Otherwise, if anybody is using Batch Plus, then subsequent user will get error message like Batch Plus is locked by.... and launch fails.
Keywords: citrix
open
project
access
References: None |
Problem Statement: Is it possible to have two separate outlet streams for two phases from a HeatX block to represent a condenser or vaporizer?
I have two separate nozzles for vapor and liquid outlet from shell side of my heat exchanger. The vapor goes back to a column and the liquid is the product. How can I model it using a HeatX block? | Solution: The option of having multiple outlets for each side of a HeatX heat exchanger is available in AspenPlus V8.0 and higher. A simple example file that can be opened in Aspen Plus V8.4 and higher is attached.
First, connect more than one outlet to the Hot or Cold port of the heat exchanger.
Then, specify the phase on the HeatX Setup | Streams sheet.
Keywords: HEATX
References: None |
Problem Statement: How do you incorporate cross linking in polymerization kinetics? | Solution: Crosslinked polyemrs usually involve reactions with pendant double bonds. Pendant double bonds (vinyl segments) resulting from the propagation of diene monomers such as 1,3-Butadiene can generate cross links between polymer chains.
The polymer attributes XLFLOW and XDENSITY are used to track the mole flow of cross links and the cross linking density. Please make sure to include XLFLOW and XDENSITY attributes from Aspen Properties > Polymers > Characterization > Attribute List
Key Words
Double Bond, Cross-Link, Attribute
Keywords: None
References: None |
Problem Statement: For a metallocene copolymerization reaction of monomers M1 and M2, can we determine the fraction of active catalyst that have M1 as the last inserted monomer? | Solution: Polymer attribute “LSEFLOW” needs to be included in the list of attributed calculated during polymerization process.
LSEFLOW will track the flow rate of live end segments for each type of active site. With calculated LSEFLOW, the catalyst flow rate and maximum active sites we should be able to work out the fraction or concentration of M1 as the last inserted monomer (e.g., the end of the chain).
Key Words
Metallocene, Monomer, Catalyst
Keywords: None
References: None |
Problem Statement: I'm trying to load an old simulation (created with Aspen Plus 2006.5 or older) with Aspen Plus V7.0 (or higher). I get a ID Conflict window such as shown below.
Why am I getting this window? What should I do? | Solution: The documentation mentions in the What's new in V7.0:
IDs for Design Specs, Calculators, Transfers
Design Spec, Calculator, and Transfer blocks may now be placed on the flowsheet. A side-effect of this is that they must have unique IDs. When opening backup files from previous versions where Design Specs, Calculators, Transfers, and unit operation models do not all have unique IDs within a hierarchy level, the Resolve ID Conflicts dialog box will appear to let you rename the conflicting items.
You get this window because in version v7.0 we changed the rules for object names: you may not have two objects with the same name, such as a block, a calculator block and a design spec. This change has been implemented to allow users to display design specs and calculator blocks on the flowsheet. As another side effect, the change also prevents users getting another error message when they want later to turn their simulation to the equation oriented mode. In the graphical user interface of v7.0 or higher, the user gets a message that the object name is already in use. The issue applies only to old simulations in which the user was allowed to use such names.
The onlySolution is to resolve those ID conflicts. You need to make sure the names are unique: you can click the block name, then the button Change Name and enter a new name.
Keywords: ID Conflict
References: None |
Problem Statement: Which emission model to use for Purge Operation? | Solution: In Purge operation, if you go to Model tab, take a look at the emission models available to this operation, you will see Purge, Sweep, Depressurization and other emission models are available to this operation.
Although this is confusing, one should NOT use Purge or Sweep emission model for Purge operation. Otherwise you will see the following message, Warning: Purge operation emissions should be calculated with evacuation instead of gas sweep/purge equations.
The emission model one should use for Purge operation is evacuation model, such as ACT Evacuation, CTG Evacuation or MACT Depressurization model. The reason being that, Purge operation has nothing to do with a high flow gas sweep. It is a pressurization with gas (usually non condensable) followed by an evacuation and repressurization. The depressurization equation is calculated using this pressure range.
Purge/Sweep emission models were retained for upward compatibility.
Keywords: Emission
Purge
References: None |
Problem Statement: HP announced in June 2005, they would stop selling their Fortran Compiler, HP Visual Fortran 6.6 on December 1st, 2005. HP also advised users to migrate to Intel Fortran Compiler version 9. | Solution: Currently, the following Aspen Tech products allow compiling user routines using HP Visual Fortran:
? Aspen Plus
? Aspen Properties
? Aspen Dynamics
? Aspen Custom Modeler
? Aspen Adsim and Chromatography
Attached PDF file (Japanese) is a summary of the compatibility of the various versions of our products with both compilers.
Keywords: Japanese
Intel Visual Fortran
Compaq Visual Fortran
HP Visual Fortran
CVF
compiler
References: None |
Problem Statement: Why does the temperature of water increase when the pressure decreases? | Solution: The Joule–Thomson coefficient is defined as the change in temperature with respect to an increase in pressure at constant enthalpy.
At room temperature for most vapors (including steam), Joule-Thomson expansion lowers the temperature. Some notable exceptions are hydrogen, helium, and neon. However, for liquids at temperatures well below their critical temperature, the Joule-Thomson coefficient is typically negative, meaning that a decrease in pressure actually raises the temperature.
Because liquid water has a negative Joule–Thomson coefficient at low temperatures (below approximately 250C), the water cools as it compresses and heats as it expands.
Keywords: Water, depressuring, Joule-Thomson
References: None |
Problem Statement: I am attempting to see if Aspen Plus correctly predicts the solubility of oxygen in water. To do this I flash a mixture of oxygen and water and take the concentration of oxygen in water for the liquid outlet. I use UNIFAC as property
method and Oxygen as Henry component. However, based on Aspen reports, I get ~39 mg/l but literature reports 8.3 mg/l for oxygen solubility in water (@ 25 ?C and 1 atm). | Solution: Water solubility of Oxygen at 25 ?C and 1 bar is calculated by Aspen Plus as 39.3 mg/l. In air with a normal composition at sea level, the Oxygen partial pressure is 0.21 bar. This results in disSolution of 39.3 * 0.21 = 8.3 mg Oxygen/l in water that comes in contact with air, which is the value reported on literature.
Keywords: Oxygen solubility, property values reported on literature, discrepancies.
References: http://water.usgs.gov/owq/FieldManual/Chapter6/table6.2_6.pdf |
Problem Statement: After EO synchronization, or some other time, all the messages in the Control Panel unexpectedly disappear. | Solution: When you reinitialize a simulation, the Control Panel messages are cleared intentionally since the old messages no longer apply. When you click the Purge Messages button, the messages in the Control Panel are cleared.
In certain rare cases, the Control Panel may appear to blank out during a run. If this happens, closing and re-opening the Control Panel should restore the missing messages.
Keywords: None
References: None |
Problem Statement: How is Heat Capacity calculated in Batch Plus? | Solution: All mixtures in Batch Plus are considered to be ideal. No calculations are performed for vapor-liquid or liquid-liquid equilibria. The extended Antoine equation is used to calculate vapor pressure for the vapor emission models. The actual equations for these models will not be listed here. They can be found in Batch Plus Help
Batch Plus will calculate the heat capacity of pure components and mixtures if a constant heat capacity is not entered in the Pure Component dialog box. The DIPPR, BARIN, Ideal Gas, and Solids Heat Capacity Models are polynomial expressions used to calculate heat capacity of pure components at various phases and temperatures. These models contain between 1 and 11 parameters (C1 - C11) which can be viewed and modified in the Pure Component dialog box.
Liquid Heat Capacity is calculated using the DIPPR Liquid Heat Capacity model if the first parameter, C1, is available. If missing, liquid phase BARIN equation parameters are checked for availability. The BARIN equations are used when other parameters are missing and BARIN equation parameters are available. If missing, BARIN values are defaulted to those of water at 25 degrees C.
Vapor heat capacity is calculated using the DIPPR Ideal Gas Heat capacity model if parameter C1 is available. If missing, parameters for the Ideal Gas Heat Capacity polynomial are checked for availability. If missing, the Ideal Gas Phase BARIN equation parameters are checked for availability.
Solid heat capacity is calculated using the Solids Heat Capacity Polynomial if parameter C1 is available. If missing, solid phase BARIN equation parameters are checked for availability.
For mixtures, when the heat capacity has not been entered, a simple mixing rule is applied. Each material consists of separate phases that are assumed to be in equilibrium with each other. Each phase is a homogeneous mixture of pure components and its physical properties are assumed to be continuous in a single phase. The heat capacity of a mixture is calculated from the molar average of its individual phases and subsequently, the heat capacities of its pure component constituents. For the exact formula, see Help for Contents of a Vessel.
Frequently, during the processing of a batch, a sample is taken from a vessel and key properties are measured. Such measured property values may differ significantly from those calculated theoretically, and may impact the equipment size utilization calculations. Batch Plus allows you to enter heat capacity values directly into the Recipe. These values are then used in the simulation. Measured values can be entered for any vessel in a batch or continuous Operation using the Measured Values button in the Misc. tab of the Operation data entry dialog. Heat capacities entered in this way are not carried over to other vessels, and must be entered for each operation.
Keywords: Heat Capacity, DIPPR, BARIN, Ideal Gas
References: None |
Problem Statement: When trying to run a simulation with NC solids I get the following message in the Control Panel and the calculations stop:
NON-CONVENTIONAL ENTHALPY MODEL ENTHGEN HAS MISSING PARAMETERS
NON-CONVENTIONAL DENSITY MODEL DNSTYGEN HAS MISSING PARAMETERS | Solution: NC solids are materials characterized in terms of empirical factors called component attributes. Component attributes represent component composition by one or more constituents.
The simulation is not running because you need to enter the heat capacity (HCGEN) and density (DENGEN) parameters in the Properties environment on the Methods | Parameters Nonconventional forms:
ENTHGEN is a general model that gives the specific enthalpy of any nonconventional component as a simple mass-fraction-weighted-average for the enthalpies of its individual constituents. The specific enthalpy of each constituent at any temperature is calculated by combining specific enthalpy of formation of the solid (DHFGEN parameter) with a sensible heat change (HCGEN parameters).
Please note that the structure for HCGEN is: Elements 1 to 4 are the four coefficients for the first constituent, elements 5 to 8 are the coefficients for the second constituent, and so on.
.
DNSTYGEN is a general model that gives the density of any nonconventional solid component. It uses a simple mass fraction weighted average for the reciprocal temperature-dependent specific densities of its individual constituents (DENGEN parameters).
In the same way, the structure of DENGEN is: Elements 1 to 4 are the four coefficients for the first constituent, elements 5 to 8 are the coefficients for the second constituent, and so on
Both of these parameters contain data for each constituent following the order that the each is defined in the general analysis.
Keywords: Non-conventional solids, missing parameter, HCGEN, ENTHGEN, DENGEN, DNSTYGEN.
References: None |
Problem Statement: How do I copy an entire facility and transfer it into another project? | Solution: To copy an entire Facility from another Project:
1. On the source drop-down list on the left-side of the dialog, click the Facility to be copied.
2. Click the Add Facility button to bring up the Add Facility to current project dialog, which is shown in the following screen:
You have two options when copying a Facility:
You can have all the Equipment Units in the source Facility added to a destination Facility.
You can create a new Facility to which all the Equipment Units in the source Facility will be added.
If you choose the first option, Aspen Batch Process Developer automatically overwrites any Equipment Units in the destination Facility with those units in the Source Facility that have the same name.
If you choose the second option, you are prompted to enter a name for the new facility.
3. Select the appropriate option.
4. Click OK.
Keywords: Facility, Equipments
References: None |
Problem Statement: What is the difference between Run/Simulate Batch and the Play button? | Solution: Run -> Simulate Batch always reads the data and simulates the whole step, but the play button will detect the change you have made after previous simulation and simulate the operations supposedly affected.
On some occasions, the play button does not detect the modification properly, so the simulation results may be incorrect. However, if you notice the subsequent simulation is the same although the input is changed, it is always good idea to use Run/Simulate Batch to confirm.
Keywords: play button
run
simulation results
References: None |
Problem Statement: How to import equipment from another Project into a Batch Plus simulation? | Solution: From the main menu, go to Data\NetworkSelect\Equipment. Under Select Equipment from:, click the browse button. Browse the directories and choose the equipment file (Projectname.eqm) . The equipment in this file will appear in the left side of the window. You can import all equipment by clicking Add Facility or click Add to import selected equipment.
Note: the equipment database file Projectname.eqm can be on a local PC or network.
Keywords:
References: None |
Problem Statement: How are vessel Capacity or Total Volume and Maximum Fill Factor used? | Solution: Capacity: used in batch operation
Maximum Fill Factor: used in conjunction with Capacity to determination of vessel overflow. Total Volume: used in vapor emission calculation.
When Total Volume and Maximum Fill Factor are not specified, Total Volume = Capacity and Maximum Fill Factor = 1.0 are implied.
Keywords: Vessel, capacity, total volume, fill factor
References: None |
Problem Statement: How does the Power law expression for the U Method in HeatX work? | Solution: The power law used in this case is simply an empirical expression, meant to allow the user to adjust a reference global U value based on the flow of either the hot side, the cold side, or both.
One should specify the controlling side as the flow variable unless both sides contribute to the U and therefore both should be considered.
The reference U value is multiplied by a term of the form (flow/ref flow)^exponent for whichever side is specified as the flow variable. If both have been specified, U will be multiplied by two terms like this -one for each side.
Keywords: HeatX, U method, power law
References: None |
Problem Statement: My Polymers Plus model uses the PC-SAFT property method. This is a user model in version 10.2. I understand that it is a system model in version 11.1. How do I convert my file so that it uses the system model? | Solution: Open the file in version 11.1
If this is the first time you are opening the file in version 11.1, you will be prompted for a decision about upward compatibility. The choice you make (Maintain complete upward compatibility vs. Use the following new features) will not affect the PC-SAFT property method.
Write down the names of the Data / Properties / Parameters / Pure Component object(s) where the PC-SAFT parameters PCSFTM, PCSFTR, PCSFTU, PCSFTV reside. If the parameters reside in less than 4 separate objects, also write down the row number of the parameter in the objects with more than one parameter.
Assuming that you are using the PC-SAFT user model as the global property method, go to Data / Properties / Specifications / Global
4a) If the PC-SAFT user model is not the global property method, go to a unit operation which uses it (look in Data / Blocks / BLOCKID / Block Options / Properties)
Write down the name of the Property Method (not the Base Method).
Change the Property Method (not the Base method) to POLYPCSF. If you are doing this on the Data / Properties / Specifications / Global form, this will also change the base method name to POLYPCSF.
6a) If the PC-SAFT user model was not the global property method, go to other blocks which use the PC-SAFT user model and change these to POLYPCSF
Go to Properties / Property Methods.
Delete the object whose name you wrote down in step 5.
8a) If the PC-SAFT user model was not the global property method, deleting the user model will cause any blocks that you did not change from the PC-SAFT user model to POLYPCSF to revert to the global property method. Thus, make sure you cover all the relevant blocks in step 6a.
Go to Properties / Advanced / User Parameters.
Delete the rows with the names PCSMIJ and PCSUIJ. Note that PCSMIJ and PCSUIJ are not accessible by the POLYPCSF system model. If you have manipulated these parameters to fit binary data, you will need to refit using PCSKIJ only.
Open the Properties / Parameters / Pure Component object(s) where the PC-SAFT parameters PCSFTM, PCSFTR, PCSFTU, PCSFTV resided. Note that the parameter name fields are now empty.
Select the appropriate parameter name from the drop-down list. Make sure the units of PCSFTU are K.
You should be done; the status should show Required Input Complete. You can also delete reference to the pcsaft.dll file (see the .opt or .dlopt file listed in Run / Settings / Engine Files / Miscellaneous files / Linker options), since this .dll is only used by the user model.
The attached file Conversion Instructions.zip has a Word document with these same instructions, augmented by screen shots obtained during implementing the procedure on an example file.
Keywords: PC-SAFT, POLYPCSF
References: None |
Problem Statement: The components in the Stream Table may not be shown in alphabetical order. Why? | Solution: The components are listed by the numerical IDs assigned by Batch Plus. When sorting the list in Excel, apply sorting to the entire set of rows, not just the components.
Keywords:
References: None |
Problem Statement: An Extract operation is used in Batch Plus; however, there is no specification allowed for the destination of the upper phase.
OR
A Decant operation is used in Batch Plus; however, there is no specification allowed for the destination of the lower phase.
Which layer is collected? | Solution: The Extract and Decant operations are very similar. If you want to specify the destination of the upper phase, use the Decant operation. If you want to specify the destination of the lower phase, use the Extract operation. The other phase remains in the equipment at the end of the operation.
Note that the Batch Operation Toolbar icons can be useful to remember this distinction.
Keywords:
References: None |
Problem Statement: Material database is missing to select the components. | Solution: Aspen Batch Process Developer uses Enterprise databank from Aspen Properties. If Aspen Batch Process Developer is not patched compatibly with Aspen Properties then Data | Network Select | Material view will display Empty list. Cumulative Patch installed for Aspen Plus or Aspen HYSYS will also update the Aspen properties with the same patch, but if the Aspen Batch Process Developer is not updated with the Cumulative Patch, then this scenario comes up.
Fix for this issue is to apply the latest cumulative patch for Aspen Batch Process Developer.
Keywords: Data, Network Select, Materials, Aspen Properties, Enterprise Database.
References: None |
Problem Statement: Is it wise to specify DHFORM for the entire polymer? | Solution: You can specify the heat of formation for the segment or the polymer; however, there are different implications if you are considering other segments.
Polymer parameters take higher priority than segment parameters. If you specify the parameter for the polymer component, this value is always used, regardless of the segmental composition.
If you specify parameters for the segment (and not the polymer), and you have more than one type of segment, the model will use the molar average of all segments to get the overall heat of formation. Typically, this method is preferable.
Keywords:
References: None |
Problem Statement: I cannot open an input file from the Graphical User Interface. | Solution: If the input file was created from an old version of Aspen Plus there may be some compatibility issues trying to open it in a newer version. What you can do to work around this problem is the following:
1. Launch Aspen Simulation Engine from Start/Programs/AspenTech/Process Modeling Vxx /Aspen Plus/Aspen Plus Simulation Engine.
2. Browse to the folder containing your input file using DOS accepted commands. Type cd foldername to select a folder, and cd.. to go back to the previous folder.
3. Type aspen nameoffile.inp /mmbackup.
This procedure will run the input file and create a backup file. Note that the name of the file must contain only alphanumeric characters (so you may need to rename your file). It is important to note also that after typing nameoffile.inp you must include a space and then type /mmbackup.
Keywords: GUI, export, import,upward opening
References: None |
Problem Statement: Polymers Plus installation completes but no entry is added in Windows Start\Programs\Aspentech\Aspen Engineering Suite menu | Solution: Polymers Plus is a layered product within Aspen Plus and will not have any entry under:
Start\Programs\Aspentech\Aspen Engineering Suite; however Polymers Plus forms are installed after product installation. To verify that Polymers Plus is installed, start Aspen Plus and select Tools/Options/Startup, the following window will appear with Polymers Plus option checked.
Make sure Polymers Plus option is checked then start using the product.
Keywords: Polymers Plus
PolymersPlus
polymersplus
polymers plus
References: None |
Problem Statement: I am unable to find chain-size distribution on the Stream Results | Poly Curves sheet, even though a Polymer ID has been specified on Components | Polymers | Distributions form. The chain size distribution shows zero on the Poly Curves sheet. | Solution: The method to track chain length distributions is not valid for all types of reactions. The method assumes that polymer molecules are stable once they are formed, therefore, it is not valid for reversible living polymerisation. It is supported by: Free-Radical, Ziegler-Natta and Emulsion reactions. It is not supported by: Step-Growth, Segment-based and Ionic reactions.
Keywords: Free-Radical, Ziegler-Natta, Emulsion reactions, Step-Growth, Ionic reactions.
References: None |
Problem Statement: Why are there no vapor emissions reported for my drying operation? | Solution: The models available for calculating the vapor emissions from drying are
1978 CTG Drying Wet Solids
1978 CTG Vacuum Drying
1994 ACT Drying Wet Solids
1996 AT Drying Wet Solids
They should be used to calculate the emissions associated with drying solid product in a dryer with no emission control equipment. The calculation is based on the difference between initial moisture content and the final moisture content in the cake. See online help for Drying Wet Solids.
If no vapor emissions are being reported for a drying operation, follow this procedure :
Make sure that vapor emissions are enabled under Tools/Options/Simulation Batch by checking the Enable Air Emission Calculation box.
In the Model tab of the Drying Operation Dialog box, ensure that the No vapor emissions for this operation box is NOT checked.
Check that a material in the solid phase has been charged or added to the dryer from a previous Charge or Transfer operation. All of the drying models require a weight of dried product cake to calculate the total mass of vapor emitted. If there is no solid mass in the dryer, Batch Plus will use a value of zero for the weight of dried product cake, and the calculated vapor emissions will be zero.
Keywords: Vapro Emissions, Solid, Drying, Wet, Vacuum
References: None |
Problem Statement: After adding a new user library, how do I make sure that it is reference and shown in the model palette in future flowsheets? | Solution: The library is listed in Manage Libraries but is not selected, which is the expected behavior; we don't by default open all of a user's known libraries for a new simulation unless he asks for it. If you select it in Manage Libraries, the models appear in the palette.
To allow easy creation of new simulations with a set of libraries already referenced, create a new blank simulation or a new simulation from one of the built-in application templates, and click File | Save As | Template to save a new application template. Then, when opening a new simulation, start with the newly created template.
Keywords: None
References: : CQ00456209 |
Problem Statement: How do I model a terminal double bond polymerization in Aspen Polymers? | Solution: For some catalyst systems, primarily metallocene, polymer chains with long chain branches are formed. However, the long chain branching frequency is usually small. The long chain branches are believed to be due to propagation
reactions involving a live chain and a terminal double bond on a dead polymer chain. Polymer chains with terminal double bonds are formed by some of the chain transfer reactions. To form long chain branches, the metal center must be open to provide a favorable reactivity ratio for the macromonomer.
The concentration of terminal double bond (TDB) end-groups on the dead polymer chains are tracked through an additional segment called the TDBSegment. TDB-Segments are generated through the chain transfer reactions
and are consumed through the TDB polymerization reaction. When the TDB reaction is used, one additional segment needs to be defined in the Components form for the TDB-Segment. Typically, for a copolymerization
system with N monomers, N repeat segments would be defined in the Components form. However, with the TDB polymerization reaction, N repeat segments and one end segment should be defined in the Component form.
The end segment must be specified as the TDB-Seg species in the Species folder of the Ziegler-Natta kinetics.
To set up the simulation:
1. Include a segment to represent the terminal double bond. The segment database includes several TDB segments out of the box (one less hydrogen than the corresponding monomer).
2. Declare the TDB segment an ?end? segment in polymer characterization Segments form.
3. Declare the TDB segment an ?end? segment in polymer characterization Segments form.
4. TDB Polymerization reactions are not automatically generated. You need to add them manually. Use the 'New' button on the Reactions tab to add TDB-POLY reactions. You can add as many as you need to account for multiple sites and active segments.
5. You need reactions to generate the TDB segment. Setting TDB Frac > 0 for the chain transfer reactions will cause the TDB segment to form. The TDB Frac is the fraction of reaction events that lead to terminal double bond formation.
Specify the TDB-Poly rate constants. You can usually assume these are the same as normal propagation (use TDB Frac parameter as the way to fit the model to data). The TDB polymerization reaction will increase the molecular weight of the polymer.
Keywords: tdb polymerization
References: None |
Problem Statement: If you go in Aspen Plus v7.2 under Components |Specifications on the Enterprise Database tab, only pure component data bank selection is available.
In V7.1 you could select pure component databanks and binary parameter databanks separately.
From Tools, Options, the Component Data tab allows both pure components and binary default bank search order to be nominated. So this is not adhering to the V7.2 Components | Specifications form where only pure components bank selection is possible.
Please clarify. | Solution: If you uncheck the option Retrieve binary and pair parameters automatically in the GUI, then you can select the binary parameter databanks under Components, Specifications, Entreprise database. This option prevents duplicating the parameters in the GUI (e.g. if the databank is updated, the simulation will use the latest values, which is cleaner). You can see that when this option is unchecked, the Databanks tab in binary parameters becomes disabled (because it's not used anymore).
If the option is checked (default), then the databanks for binary parameters are selected under Properties, Parameters, Binary Interaction. That's how it was in V7.1. However in V7.1, the binary databank selection was still shown under pure components, those settings were simply ignored. V7.2 hides that selection when it is not relevant to prevent any confusion. The databanks can also be selected from Tools, Options, Component Data (again, this applies only if you retrieve the parameters in GUI - the old style of Aspen Plus).
So the user has now two options:
old style - databanks are selected under Tools, Options, Component Data and under Properties, Parameters, Binary interaction (and pair). Parameters are loaded into the user interface.
new style - databanks are selected on the Components | Specifications form. Parameters are not loaded up into the user interface by default when Retrieve binary and pair parameters automatically in the GUI is checked.
Let's now look at how does the default binary parameter bank get selected (this is property method dependent).
The discussion below refers to the default case where binary parameters are retrieved in GUI. The selection is based on databanks selected under Tools, Options, Component Data. For activity coefficient models (NRTL, UNIQUAC, etc), Aspen Plus tries to assist the user in the selection of the databank for binary parameters. When you select NRTL, the GUI will put VLE-IG first. If you had selected NRTL-HOC, then the GUI would have put VLE-HOC first. If you select NRTL, then change your mind and select NRTL-HOC, the GUI will leave the databank VLE-IG instead of VLE-HOC, so you'll end up with inconsistent binary parameters with respect to the vapor model (which may or may not have a dramatic impact). (This is the same for NRTL-RK, and for other activity coefficient models, such as UNIQUAC, UNIQ-RK, etc).
It's also an issue for Henry binary parameters. If you select ELECNRTL, the databank ENRTL-RK will be put first in the binary Henry parameters, instead of BINARY or HENRY. For some components (those which dissociate in ions), the parameters are very different (e.g. CO2 - in BINARY/HENRY, CO2 in liquid represents CO2 and CO3-, while in ENRTL-RK, the Henry parameter is assuming CO2, and CO3- is just not volatile since it is an ion, so the numerical value of the parameter has to be different).
This is not an issue for Equation of State (EOS) models since they have their own binary parameters though you do need to make sure that the databank is selected. If the databank is not selected in the default list, then no parameters will be retrieved.
The bottom line is that binary databank selection must be carefully checked by the user, either to ensure the selected databanks are correct (based on what's explained above) or that the binary interaction parameters are available and valid in the range of temperature and compositions (this requires carefully validation, and sometimes regression work is required).
Keywords: None
References: None |
Problem Statement: Presence of Double quotes ('') in the Setup | Specifications | Description will give the following error message:
** ERROR IN A DESCRIPTION PARAGRAPH
SKW: DESCRIPTION
INVALID USE OF POSITIONAL NOTATION.
THE SENTENCE AS ENTERED WOULD ASSIGN THE VALUE:
QUOTES TO TERTIARY KEYWORD NUMBER 2.
HOWEVER, THERE ARE ONLY 1 VALID TERTIARY | Solution: Double quote () have not been allowed in the description since 2006.5. Single quote (') are allowed. If the file is saved using 2006.5 or earlier, delete the double quote () from the description. You will not be able to re-enter it.
Keywords: FOR THIS SENTENCE. SENTENCE IGNORED.
References: : CQ00432897 |
Problem Statement: What's New in Aspen Plus V7.3? | Solution: Aspen Plus V7.3 includes many new and improved features to help you save time and effort developing new conceptual designs, evaluate relative capital and operating costs for alternative process schemes, improve the energy efficiency of your processes, and examine the carbon footprint of proposed designs.
There are many reasons to upgrade to Aspen Plus V7.3, including the following:
1. Save weeks of effort collecting physical property data to validate or fine tune the thermodynamics in your process models. With Aspen Plus V7.3, the NIST ThermoData Engine provides access to over 3 million mixture property and phase equilibrium data points for over 30000 pairs of components, as well as pure component data for over 24000 species.
See knowledgebase article 131612 for more details and to view a short demonstration of this feature.
2. Many nations and states now require manufacturing companies in the continuous process industries to report greenhouse gas emissions. Aspen Plus V7.3 includes new features to calculate and report greenhouse gas emissions and evaluate the annual carbon tax for your process.
See knowledgebase article 131613 for a detailed explanation and to view a short demonstration.
3. Integrated economic analysis makes it easy for Process Engineers to us AspenTech's rigorous and proven cost modeling technology from inside Aspen Plus. Use estimated capital and operating costs to make better engineering design decisions. Compare alternatives on a consistent basis using relative costing early in the conceptual design process, then send the preliminary cost files to your cost estimation department for detailed estimates using Aspen Capital Cost Estimator. With Aspen Plus V7.3 you can even customize the costing and sizing algorithms using your own MS Excel worksheets and Aspen Process Economic Analyzer templates.
See knowledgebase article 131614 to learn more about these and other costing improvements and to view a short demonstration.
4. With Aspen Plus V7.3 you can export heat exchanger data from your process model directly to Aspen's Exchanger Design and Rating tool. The new exchanger sizing feature exports exchanger and property data for heater blocks, heat exchanger (HEATX) blocks, and for the condensers and reboilers in distillation column models.
See knowledgebase article 131615 to learn about this feature and to view a short demonstration.
5. Check the energy efficiency of your process in minutes by sending the case file to Aspen Energy Analyzer. With Aspen Plus V7.3, you can do this with one mouse click. You can use the Energy Analyzer to identify and compare different heat recovery schemes against the thermodynamic limits determined by heat pinch theory.
See knowledgebase article 131616 to learn more about this feature and to view a short demonstration.
6. Make rigorous physical property calculations and data available to your entire technical staff using Aspen Properties Mobile V7.3. The Aspen Properties Mobile client runs on Apple iPhones, iPod touch, and the iPad. With Aspen Properties Mobile Chemists, Engineers, and Scientists can all have easy access to a consistent set of property data, including your in-house databases.
See knowledgebase article 130636 to learn more.
7. Stay informed with news about upcoming webinars, training events, how-to knowledgebase articles, and animated tutorials. The new Start Page features quick links to help topics, on-line customer support, and training resources to help you get up to speed quickly.
See knowledgebase article 131617 to learn more.
8. Modeling processes with solids is easier with Aspen Plus V7.3. You no longer need to define CISOLID sub-streams to carry the solids (unless you need to track particle size distributions). See ?What's New? in the Aspen Plus help for more details.
9. Aspen Plus V73 includes a new biodiesel databank containing 461 common triglycerides, diglycerides, and monoglycerides. The new PURE25 databank, based on the January 2010 DIPPR database, includes 42 additional components and updated parameters for a wide range of components. The newest NIST-TRC databank, based on the June 2010 NIST SOURCE database, includes data for over 24000 pure components. Many other improvements have been made to the physical property data and models. See ?What's New? in the Aspen Plus help for more details.
10. Aspen's Rate-Based distillation model is more accurate than ever before for packed columns. The new Hanley correlations, developed by AspenTech, apply to Pall rings, b-ETA rings, IMTP rings, CMR rings, and sheet metal structured packings. See ?What's New? in the Aspen Plus help for more details.
11. Aspen's DRYER model can be used to simulate drying of non-conventional solids, which track moisture content through component attributes. This feature is useful for simulating biomass or coal drying operations.
12. Several usability enhancements are included in Aspen Plus V7.3. The new Analysis toolbar makes it easier to create sensitivity studies, set up data regression cases, and launch residue curve and ternary analysis tools. The Analysis toolbar can also be used to send simulation data to Aspen Exchanger Design and Rating, Aspen Energy Analyzer, and Aspen Flare Analyzer.
13. There are many other enhancements in Aspen Plus V7.3. To learn more, install Aspen Plus 7.3 and click ?What's New? on the new start page. You can see all the new features of V7.3, and many previous releases.
14. Click the link below to see a summary of all the new features in Aspen Plus V7.2
What's New in Aspen Plus V7.2 - Overview
Keywords: None
References: None |
Problem Statement: Why does the objective function keep decreasing past the value reported on the Column | Analysis | NQ Curves | Summary sheet? | Solution: The traditional NQ curve is a plot of heat load (Q) against total number of stages (N). However, the concept of NQ curves is not restricted to just heat load. These curves can be used with any objective function.
The NQ Curves feature in Aspen Plus determines the curve by performing calculations at different numbers of stages. The optimum location for the main feed stream is determined for each number of stages. The locations of product streams, other feeds, pumparounds, and decanters are determined from the feed location and number of stages for each run; there are several methods available which can be chosen independently for each stream. The NQ curves analysis records the detailed results of column simulation for each number of stages. A variety of other variables, such as reflux ratio, are available for plotting.
Generally, the heat load continues decreasing as you increase the number of stages, but after a point, the improvement diminishes to the point where it becomes negligible. NQ Curves will stop increasing the number of stages when it reaches that point (or else at the maximum number of stages you specify). In either case, the finalSolution uses the optimum feed location for the number of stages it determines. In V8.8 and earlier, FinalSolution results were called Global optimum results which was unclear since the heat load continues to decrease as you add stages, but very slowly, or it may stop at the stage limit you specify, when adding stages could reduce the heat load further.
Keywords: nqcurves
References: : CQ00614001 |
Problem Statement: Aspen Plus 10.1 should be loaded and run before you attempt to use it with Batch Plus. | Solution: Batch Plus will not recognize that Aspen Plus has been installed until it has been run once. You can run the Testprob.bkp found under the \Program Files\AspenTech\Aspen Plus 10.1-0\Favorites folder.
Note that Aspen Plus 10.0 is not supported in Batch Plus 2.0b.
Keywords: Installation
Aspen Plus
Batch Plus
References: None |
Problem Statement: What happens if more than one outlet stream is denoted as the key step output? | Solution: Batch Plus will use the first occurrence of this specification.
Keywords: BATCH PLUS
Key
Step
Output
Product
References: None |
Problem Statement: How to report molar properties for a polymer in the stream report? | Solution: Aspen Plus includes in its property sets two properties to report the true molecular weight and the true molar flowrate of a polymer.
For V9, the process to add those values in the stream report is as follow:
1. Go to the stream that you want to review and select the results tab.
2. Click on add properties at the bottom of the screen
3. Type Polymer in the search form. Select TRUEFLOW and TRUEMW and click ok
4. Expand the Mixed Substream form to reveal all the properties in the report. You will find the new properties added at the bottom. If results do not appear, run the simulation again.
Keywords: True molecular weight, molar flow, polymer properties
References: None |
Problem Statement: Is it possible to define Utility (heat transfer fluid) as mixture? | Solution: Currently, you cannot use a mixture to create a utility; only pure components are allowed. You have to create a new pure component with the physical properties that the mixture would have to simulate similar heat transfer activities. Then, create a new utility based on the pure component.
Keywords: Utility, Heat Transfer
References: None |
Problem Statement: What version of Visio is required for Batch Plus 2.x? | Solution: Batch Plus 2.0, 2.0b, 2.1 and 2.2 require Visio Technical or Pro version 5.0c or higher.
Keywords:
References: None |
Problem Statement: The average molecular weight is needed to calculate equivalent and bill of material. How is it calculated for a mixture in Route Selection? | Solution: If you specify the active ingredient in a mixture, then the molecular weight should be: (active ingredient MW)/(mole fraction of active ingredient in the mixture)
If you did not specify the active ingredient, then the molecular weight should be the average MW based on mole fraction
The molecular weight in the Route Selection Results/Process Route Detail sheet is wrong. However, this MW is not used in equivalent or cost (bill of material) calculation. The MW used in the equivalent calculation is described above in (1).
Fixed by
The problem will be fixed in version 2006. - CQ205134
Keywords: Molecular weight
MW
equivalent
cost
bill of material
References: None |
Problem Statement: Installation and configuration issues may lead to problems launching Visio Equipment or Block diagrams. | Solution: Either Visio Professional or Visio Technical is required to generate Equipment or Block diagrams in Aspen Batch Plus. Visio Viewer cannot be used to generate diagrams. However, once Visio diagrams are generated, one can use the Visio Viewer to browse the diagrams.
If you encounter difficulties while trying to generate Visio Equipment or Block diagrams using Visio Professional or Visio technical, it is likely that Visio was installed after Batch Plus. Try the following steps to update the path:
1. Go to File | Preferences | Equipment Diagram
2. Check the box Check this box if you are encountering problems generating a diagram
3. Close Preferences and run the Visio Diagram.
4. You should be told that the Visio add-on path has been updated and that you should close Visio for the change to take effect.
5. Close Visio
6. Go back to preferences and uncheck the check box Check this box if you are encountering problems generating a diagram
7. Close preferences
8. Run the Visio diagram again
If the problem persists, try to change the security settings of Visio :
· Launching Visio
· Go to Tools | Macro | Security
· Change the security to Low
If the above steps fail to resolve the issue please contact AspenTech Support.
Keywords: Visio
Equipment Diagram
Block Diagram
References: None |
Problem Statement: How can I retrieve r, q and q' Uniquac parameters? | Solution: The Uniquac r, q, and q' parameters are scalar parameters for each component.
To review parameters, from the main menu, select Tools and Retrieve Parameters Results. The values for r, q and q' will be reported as GMUQR, GMUQQ and GMUQ1 respectively on the Properties | Parameters | Results | Pure Component | Scalar sheet.
Keywords: None
References: None |
Problem Statement: Why do I get large, unexplained time gaps in the simulation results? | Solution: The facility for the step is can use a non-24 hour calender where certain dates are marked non-working or exception.
Check two places:
The calender assigned to the facility. Go to the Facility tab in the project builder, select the facility and click Edit.
Preferences. If a calender is not specifically assigned, the default calendar in the Preferences will be used.
Keywords:
References: None |
Problem Statement: What are the different batch movement operations available in Aspen Batch Process Developer (ABPD)? | Solution: Following are the different batch movement operations used in ABPD:
1. Charge: Charge raw material to a unit which may include pure component, a pre-defined mixture or pre-defined cells.
2. Charge-To-Amount: Charge raw materials to an equipment unit, to a certain amount of pure Component, pre-defined mixture or pre-defined cells.
3. Line-Blow: Blow a line with gas following the transfer of material between units to remove any remaining material in the line.
4. Line-Flush: Flush a line following the transfer of material between units to remove any remaining material in the line.
5. Multiple-Transfer: Transfer material from many equipment units to a single equipment unit, or from a single equipment unit to multiple equipment units.
6. Pressure Transfer: Transfer liquid and/or solid contents from a source unit to a destination unit.
7. Transfer: Transfer the full or partial contents of a unit to another unit.
8. Transfer-Through-Heat-Exchanger: To transfer the full contents of a unit to another unit through a heat exchanger.
Keywords: definitions, operations
References: None |
Problem Statement: How to display the default vapor emission model in the Operation, Model dialog? | Solution: In the Operation, Model dialog box, click the equipment tag. You will be prompted Do you want to use the default Vapor Emission models? Click Yes, and the default vapor emission model will be filled in.
Keywords: default, model, vapor mission
References: None |
Problem Statement: How heat of polymerization is calculated in Aspen Plus and layered products Aspen Dynamics and Aspen Custom Modeler? | Solution: Refer to the attached word document.
Keywords: Heat, Polymer, Heat of polymerization, Polymerization, enthalpy.
References: None |
Problem Statement: I have installed some Aspen Plus emergency patches using the .exe file. How do I know what fixes have been installed? | Solution: Go to the Help menu and select View Update Readme to see a list of the fixes addressed in the installed emergency patch.
This list is contained in a file named readme.htm located in the ..\AspenTech\Aspen Plus V7.x folder.
Keywords: None
References: None |
Problem Statement: How is it possible to change icons in Visio for Batch Plus Equipment Diagram? | Solution: You can change the icons used in Visio. Refer to the online help under User Manual/Equipment Diagram/Custom Equipment Stencil. There is one icon for each equipment class.
You can replace the icon with a bitmap of a box or create a new icon in Visio. The stream ports are called connection points. To assign a connection point, use the Blue X icon that is on the Visio Toolbar under the Connector Tool (looks like two boxes connected by a line). Because the order is important you may want to check the order under Window/ View ShapeSheet. There is a Connection Point category. If you tile the windows to see both the Stencil and the ShapeSheet you can identify the order by selecting the connection point on the ShapeSheet.
For other icons there are several Process stencils within Visio (Valves, Pipes, Instrumentation, Pumps, Compressors, Heat Equipment, Equipment and Vessels).
You may define a custom equipment stencil to be used in place of the standard Batch Plus equipment stencil. Please refer to your Visio documentation for instructions on creating stencils and masters. The file User.vss is now called BPUser.vss.
To be compatible with Batch Plus:
Name your stencil User.vss and place it in the Templates sub-directory of your Batch Plus installation directory (e.g. Batch Plus 2.2\Templates\Visio). A starter BPUser.vss stencil has been placed in the \Templates\Visio directory by the Batch Plus installation. You may use this stencil as a starting point for your own custom stencil.
Name your equipment masters after Batch Plus Equipment Classes. The starter stencil has a complete list of valid Equipment Classes. If an Equipment Class is missing from your custom stencil, Batch Plus will use the standard master for the missing Equipment Class.
Include 7 connection points for each equipment master. Batch Plus will use these connection points to attach streams. The seven connection points are (in order):
Alternate input port (not used, reserved for future use) Main input port
Top output port
Bottom output port
Vapor Emission port
Main utility port
Alternate utility port (not used, reserved for future use)
Keywords:
References: None |
Problem Statement: How do I define the stream class for a solid if I want to model it using a Crusher block? | Solution: The Solids unit operation blocks such as CRUSHER require a Conventional (CI) or Nonconventional (NC) solid substream with a particle size distribution (PSD). The stream classes that include these substreams are either CIPSD or NCPSD.
The stream class is specified as MIXCIPSD (or NCPSD) on the Setup | Specifications form:
The component(s) defined as solid will be available on the CIPSD substream and those defined as nonconventional will be available on the NCPSD substream.
In the feed stream, specify the input for the CIPSD substream for the inlet stream:
After specifying the flow for the solid components the PSD tab will activate to fill in the weight fraction for the solid particles:
For the CRUSHER block, specify the power at which the particles will be grinded (in the Grindability tab):
This way, the simulation is ready to run.
Keywords: Stream class, CIPSD, crusher, solids
References: None |
Problem Statement: Is there a way to know what changes have been made in a simulation file? | Solution: There is no built-in functionality that would allow you to look for modifications in the simulation in Aspen Plus. On the other hand, there is a procedure that would allow you to know if there are any differences between two input files from Aspen Plus. First of all, the input files are summaries of the different data used by Aspen Plus during the simulation, and they can be exported at any time directly from Aspen Plus by following this procedure:
1. Go to File -> Export.
2. Select Input file (.inp) as the file type and name the file.
3. Click on Save.
Now, you could compare 2 input files created at different times with the Windiff utility from Microsoft. It usually is included in the Visual Studio installation and is commonly located in C:\Program Files\Microsoft Visual Studio X\Common7\Tools\Bin where X is the version you have. Now you can compare the two input files with the following procedure:
1. Start Windiff.exe.
2. On the File menu, click Compare Files.
3. In the Select First File dialog box, locate and then click a file name for the first file in the comparison, and then click Open.
4. In the Select Second File dialog box, locate and then click a file name for the second file in the comparison, and then click Open.
5. The information in the right pane indicates whether there is a file difference.
6. To view the actual file differences, click the first line in the Windiff.exe output results, and then on the Expand menu, click Left File Only, Right File Only, or Both File. (More information on Windiff is available at http://support.microsoft.com/kb/159214)
Keywords: Windiff flowsheet change input
References: None |
Problem Statement: After checking Estimate missing parameters by UNIFAC on the NRTL or UNIQUAC binary parameter form, the parameters are not estimated for my components that are only in the NIST-TRC databank even though there should be UNIFAC groups for them. Why not? How do I get them to be estimated? | Solution: The UNIFAC groups (UFGRP) are part of the PURExx databanks, but they are not part of the NIST databank. In order to estimate the NRTL or UNIQUAC parameters, the UNIFAC groups need to be entered or generated from the General structure of the component.
To have Aspen Plus attempt to generate the UNIFAC groups:
1. Go to the Properties | Molecular Structure | Structure sheet.
2. Click on the Calculate Bonds button.
3. Click on the Ok button to generate the General structure.
4. Re-run.
If UNIFAC groups can be matched to the structure, they will be used to estimate NRTL or UNIQUAC binary parameters.
Keywords: None
References: None |
Problem Statement: How is the Heat of Reaction calculated in Batch Plus? | Solution: Users can use the Calculate button on the Batch Plus Reaction dialog to calculate heat of reaction. This heat of reaction is calculated as the sum of the IDEAL GAS heat of formation for the reactants and products; therefore, it might be far from the actual heat of reaction at given reaction condition.
Consider the following example:
2 H2 + O2 -> 2 H2O Hydrogen and Oxygen are in the gas phase.
Water is in the liquid phase.
The reaction takes place at 25 C, 1 atm.
The heat of reaction calculated by Batch Plus is 2.412E+5 J/mol, assuming water is ideal gas at 25 C, 1 atm. However, in actuality, water at standard condition is in the liquid phase; therefore, the heat of reaction differs by heat of vaporization for water at 25 C, 1 atm, which is 4.4E+4 J/mol.
Keywords:
References: None |
Problem Statement: How do I split a stream into pure component streams? | Solution: In Aspen Plus the SEP unit operation can be used to separate a stream to pure component streams.
Sep combines streams and separates the result into two or more streams according to splits specified for each component. When the details of the separation are unknown or unimportant but the splits for each component are known, one can use the SEP block. SEP is available under Model Library Separator models.
Keywords: Component separator, component splitter etc
References: None |
Problem Statement: How can the Liquid Gibbs free energy of formation (DGLFRM) parameter be accessed using a Calculator Block? | Solution: Parameter DGLFRM is only available for WILS-LR and WILS-GLR property methods, that is why in order to access and use parameter DGLFRM in Calculator block one of these methods has to be chosen for the entire simulation.
Having selected one of these methods, you can find DGLFRM in the Calculator Block Variable drop-down list, by selecting the Property Parameters category, then the type Unary-Param:
It does not show up if you have not selected one of these methods because there are plenty of parameters only used by specific models and the list would be too long if we would include all parameters available in Aspen Plus for every method.
Keywords: Liquid Gibbs free energy of formation, DGLFRM, Calculator Block, Unary-Param, WILS-LR, WILS-GLR.
References: None |
Problem Statement: How is mixture Density or Molar Volume calculated in Aspen Batch Process Developer? | Solution: All mixtures in Batch Plus are considered to be ideal. No calculations are performed for vapor-liquid or liquid-liquid equilibria.
Vapor Phase:
Ideal gas molar volume is calculated from the Ideal Gas Law if a constant density has not been entered by the user.
Liquid Phase:
The liquid mixture density is calculated from either the Ideal Liquid Mixture Density Equation or the Rackett Liquid Mixture Density Equation. The user has the option of choosing one of these models in physical properties preferences. The physical properties preferences can be found in the File Menu - Preferences. This brings up a dialog box with buttons for all the preferences. One of the buttons is titled Physical Property. Click this button to select either the Ideal Liquid Mixture or the Rackett Equation
If you choose Ideal Mixture Density, pure component density is calculated (using the pure component density rules of DIPPR first and Rackett if DIPPR is not available as described inSolution 129275 ) and then averaged by inverse mole fraction.
If you choose Rackett Mixture Density, no pure component densities are calculated (see attachedRackett Liquid Mixture Equation document). Instead the critical properties for the components are built for the mixture and then applied to a single density calculation as though the mixture were a single component.The Rackett Liquid Mixture Density Equation is based on the principle of corresponding states, which implies that fluids behave similarly when they are in similar corresponding states. Based on this principle, the Rackett equation can be applied to a liquid mixture if critical mixture properties can be calculated. When selected, the Rackett Liquid Mixture Density Equation will be applied to those liquid components whose critical properties are defined. If the critical property of a component is not defined, that component modifies the liquid mixture density following the Ideal liquid mixing relationship.
For electrolyteSolutions, while the Rackett equation does a better job of predicting the densities than the Ideal equation, these values may still not be as accurate as those predicted by equations specifically developed for electrolyteSolutions. For example, for a 37% w/wSolution of concentrated hydrochloric acid at 25 C, the Ideal equation predicts a density of 0.91 g/cc and the Rackett equation predicts a density of about 1.03 g/cc. The correct density is about 1.18 g/cc. To more accurately model the densities of electrolyteSolutions in Batch Plus, the following suggestions are offered to the user:
1. Use the constant liquid density field of the pure component. All liquid density calculations will then use this value. In the concentrated hydrochloric example, set the constant liquid density of Hydrogen Chloride to 1.75 g/cc.
2. Use the measured density feature that is available for all operations. If a measured density is specified for a vessel in an operation, Batch Plus will use this value in its calculations.
Solid Phase:
For pure solids not dissolved in a liquid, the Solids Volume Polynomial is used to calculate the solid volume if parameter C1 is available. If missing, the volume is defaulted to that of water at 25 degrees C.
If a solid is dissolved in the liquid phase, all the properties will be calculated using the liquid state parameters since it behaves similar to a liquid, and it is viewed as a fluid. If liquid parameters are not specified, the default water density is used for the dissolved solid component. The Solid Volume Polynomial only applies when the solid is in the solid phase. For solids that dissolve in liquids, it is suggest that users define the Constant Liquid Density field in the material properties description data entry since the liquid state parameters are frequently missing for the dissolved solid components.
Equations for Rackett and Ideal Liquid mixture density are attached and also can be found from Aspen Batch Process Developer Help menu.
Keywords: Density, Molar Volume, Rackett, Ideal Mixture, Mixture
References: None |
Problem Statement: Is there a complete list of status codes for the field (Aspen.Tree.FindNode('\Data\Results Summary\Run-Status'),12) ?
This is the first field in the panel completion status. | Solution: The following is the list of completion status in hexadecimal.
HAP_RESULTS_SUCCESS = 0x1,
HAP_NORESULTS = 0x2,
HAP_RESULTS_WARNINGS = 0x4,
HAP_RESULTS_INACCESS = 0x8,
HAP_RESULTS_INCOMPAT = 0x10,
HAP_RESULTS_ERRORS = 0x20,
HAP_INPUT_INCOMPLETE = 0x40,
HAP_INPUT_COMPLETE = 0x80,
HAP_INPUT_INACCESS = 0x100,
HAP_INPUT_NEUTRAL = 0x200,
HAP_UNRECONCILED = 0x400,
HAP_RECONCILED = 0x800,
HAP_DISABLED = 0x1000,
HAP_ENABLED = 0x2000,
HAP_EOSYNC = 0x4000,
HAP_EODISABLE = 0x8000,
HAP_EOFAIL = 0x10000,
HAP_EOERROR = 0x20000
For example: 129 is 81 in hexadecimal, that means HAP_INPUT_COMPLETE ans HAP_RESULTS_SUCCESS.
Keywords: None
References: : CQ00419742 |
Problem Statement: Is it possible to add polymer segments to Aspen Custom Modeler or Aspen Dynamics after changing segment list in Aspen Plus?
After creating an Aspen Dynamics file from Aspen Plus, more segments or monomer were need. These were then added in Aspen Plus and add those to the component list, and a new .APPDF file was created to replace the existing one in the dynamic simulation. However, when launching Aspen Dynamic again, the newly added segments were not present. What is wrong? | Solution: This situation arises because Aspen Custom Modeler and Aspen Dynamics allow the user to apply a subset of the segment list. In general, Aspen Custom Modeler is more flexible in handling the component list compared to Aspen Plus (which has all components in all streams). Aspen Custom Modeler and Aspen Dynamics allow the user to use subsets of the component lists in various sections of the flowsheet. This concept is extended for polymers, allowing the user to select a subset of the segment list. To have the additional segments in the simulation, they need to be added to the subset for the simulation.
Step by step instructions:
In Explorer window for Aspen Custom Modeler or Aspen Dynamics, click component list.
Double click Default.
Use Edit Physical Properties button to add segment to simulation.
Keywords: polymer
segment
References: None |
Problem Statement: Reconciling Physical Property Data in Aspen Plus and Batch Plus | Solution: Currently Batch Plus 2.x and Aspen Plus 10.x use different database structures for storing Physical Property information for components (materials). Aspen Plus stores the pure component property data in a binary proprietary data file whereas Batch Plus stores the data in an Access database. In this document we have described one possible way to store your physical properties data in an In-house databank in Properties Plus/Aspen Plus which can then be shared with Batch Plus and vice versa.
Batch Plus to Aspen Plus
The material properties data from a Batch Plus project is stored in an Access database file. The properties information needs to be transferred into an In-house property databank in Aspen Plus. In-house databanks are independent of the Aspen Plus system databanks and are created and maintained centrally by your Aspen Plus system administrator. The In-house databank is then accessible to everyone connected to that engine with the customized user interface.
General Procedure:
Locate the Batch Plus Access database file. The properties data from a Batch Plus project is stored in an Access database file. This file is saved with the Batch Plus project file and the name projectname.MTL.
Save the Access database as a text file.
Write a script to create a DFMS input file from the text file. DFMS (Data File Management System) is a system for creating physical property databank - it is a peripheral system of Aspen Plus. The execution procedure for DFMS is different for each operating system. The DFMS input file is a text file with the extension .INP (e.g. myfile.inp) written in DFMS input language. The DFMS input language is documented in the Aspen Plus Physical Property Data
Keywords: Batch Plus
Aspen Plus
Physical Property Data
References: Manual, Chapter 1, Databanks. This is the major step in the process. Any programming technique can be used to transform the data into the DFMS input language. The names of the property parameters will be the same in both Batch Plus and Aspen Plus.
Below is an example of a DFMS input file that that contains the Antoine Equation coefficient for water:
; DFMS input file for creating an in-house databank
; FILE NAME: DATA10.INP
;
FILE INHSPCD INHSPCD NEW
WRFILE INHSPCD
;
NEW-COMP WATER H2O
;
NEW-PROP PLXANT 9
;
PROP-DATA
PROP-LIST PLXANT 1
PVAL WATER 9 -1 0 0 0 0 0 10 500
;
END-INPUT
Run the DFMS to create/update the In-house property databank The DFMS run creates/updates the databank file (inhspcd.dat) in the Aspen Plus system directory. A report file summarizing the contents of the databank is also generated in the directory from which DFMS is executed.
Customize the Aspen Plus Graphical User Interface to show the In-house databank and its chemical components. The process of customizing the Aspen Plus User Interface is described in the Aspen Plus System Management Reference Manual, Chapter 6: Configuring Physical Property Databanks.
Aspen Plus to Batch Plus
The pure component (material) properties data in Aspen Plus are stored in the system Pure Component Databanks. The DFMS peripheral can used to report the property parameters by generating a DFMS report (ASCII text file). The DFMS report file can then be converted into an Access database that can be copied into a Batch Plus project as the global materials database. General Procedure:
Generate a DFMS report file with all of the physical property parameter data from a given Aspen Plus pure component databank (e.g. In-house databank) DFMS (Data File Management System) is a system for creating physical property databank - it is a peripheral system of Aspen Plus. DFMS can also be used for reporting property parameters. The execution procedure for DFMS is different for each operating system. The DFMS input file is a text file with the extension .INP (e.g. myfile.inp) written in DFMS input language. The DFMS input language is documented in the Aspen Plus Physical Property Data Reference Manual, Chapter 1, Databanks. Below is an example of the input file used to create a report with all of the data in the Aspen Plus PURE10 databank:
FILE PURE10 PURE10
PRINT-DATA PURE10 ALL ALL
ENDINPUT
All desired Aspen Plus pure component databanks should be accessed. Batch Plus also includes the INORGANIC and SOLIDS databanks from Aspen Plus.
Convert the data from the DFMS report file into an Access database in the format that is required by Batch Plus. This is the major step in the process. Any programming technique can be used to transform the data into the Access database. It may be useful to use an intermediate step of putting the data from the text report file into a spreadsheet program. The names of the property parameters will be the same in both Batch Plus and Aspen Plus.
Copy the property data into a Batch Plus project. Go to Data/Network Select/Pure Component and click on the button with 3 dots in it to select the Access database and then copy the desired components into the current project. |
Problem Statement: For an equation of state model, it seems that the Heat of Vaporization equation is not used. Is this correct? How is the liquid enthalpy calculated in this case? Via the ideal gas heat capacity ? And if so, how does it then calculate the departure term from vapor to liquid, if the heat of vaporization is not included specifically?
If you go to Tools/Analysis/Property/Pure... you can select DHVL, even though the help suggests that this property can only be used for Ideal and Activity Coefficient Models. | Solution: Enthalpy of vaporization for a pure component at specified temperature and vapor pressure for the component at that temperature.
The Property set DHVL (enthalpy of vaporization) in V7.1 and earlier reported the difference in enthalpy between vapor and liquid phases at the specified or stream pressure and temperature when used with an equation of state method, instead of performing this calculation at the vapor pressure of the component at the given temperature as it should have done. It gave correct results only when using the ideal method or an activity coefficient method, or when calculated for a stream at its bubble point. Also, if it was specified to be calculated for multiple components, it might have given wrong answers for some of them, even under these conditions. Now in V7.2, it calculates the correct enthalpy of vaporization under all conditions, calculating the pressure using a bubble point flash (performed internally as part of the prop-set calculations) for equation-of-state methods and using the general vapor pressure model in other cases. It no longer takes a pressure specification. In earlier versions, to obtain meaningful DHVL for an equation-of-state method, use Properties | Analysis and flash a single component at specified temperature(s) and vapor fraction equal to 0.
Keywords: None
References: None |
Problem Statement: Is it possible to set the agitator speed during a heat or cool operation in Aspen Batch Plus? | Solution: The agitator speed during a heat/cool operation can only be specified with the VesselPak model (on the Model tab) in the Heat or Cool operation. Once the parameters (such as agitator speed) have been specified under the Advanced button of the Model tab (where the user selects the VesselPak model), those parameters will be used by the VesselPak model.
Keywords: agitator speed, heat, cool
References: None |
Problem Statement: Not able to run the automation example file: BatchPlusAutomationExample.doc. | Solution: Make sure that the Batch Plus type library was properly registered. Do this by opening BatchPlusAutomationExample.doc in Word. Press Alt-F11 to open the Visual Basic Editor. Select Tools/
Keywords: v2.1, version 2.1, installation, automation, Exel/VBA model, user model, Excel Model, BatchPlusAutomationExample, MaintainComponentAmountv1, Run-time error 9:, Run-time error 429
References: s from the main menu bar. Make sure that Batch Plus 2.1 Object Library is checked and that its location is correct. If the library is missing or the location is incorrect, uncheck the library, click OK (very important to click OK here). Select Tools/References again, click the Browse button. Locate and open BatchPlus.tlb (in the bin directory of the installation). Verify that Batch Plus 2.1 Object Library is checked in the window. If this does not solve the problem, do (2).
Have Batch Plus open before you run the automation file. Do this by launching Batch Plus first. Click Cancel in the file open window. Now open and run the automation file. |
Problem Statement: How can I increase number of intervals in zone analysis in HEATX? | Solution: You need to change default setting in the HEATX block
1. From the Heatx | Setup | LMTD tab, check Use interval analysis for LMTD calculation then accept the default settings.
2. Run the simulation.
3. From the Heatx | Thermal Results | Zones tab, View drop-down box, select Exchanger zones analysis.
Keywords: zone analysis, HeatX, LMTD etc;
References: None |
Problem Statement: How do I use OLI from OLI Systems (http://www.olisystems.com) with Aspen Plus? Do I need to install an interface? | Solution: There is a Readme document for the OLI Alliance Suite for Aspen OLI Interface copied to the installation directories. It is located under:
C:\Program Files (x86)\AspenTech\Aspen OLI Interface Vx.x
The presence of this Readme file indicates that Aspen OLI Vx.x has been partially installed. This document provides background information on the licensing structure, the installation process and new features in Aspen OLI.
Licensing
The Aspen OLI Interface provided by AspenTech. The interface is included with Aspen Plus and Aspen Properties and is provided without additional license. However, a license from OLI Systems is needed to run the OLI Engine. Customers should contact OLI Systems if they do not have this license.
Installation
Install the OLI Engine in order to complete the installation of Aspen OLI Interface. In V8 and higher, users need to download this executable from the OLI website (http://downloads.olisystems.com/downloads.aspx). This is a self-extracting script that installs the components supplied by OLI in a directory of your choosing (or the default location C:\Program Files\OLI Systems\). There is a 32-bit version for Aspen Plus V10 and earlier and a 64-bit version for V11 and later. During the installation, you will be asked to supply the serial number for the OLI license obtained from OLI Systems.
After the installation, the Chemistry Generator, Chemistry Wizard and Data Locator programs will be available in the Start menu located under OLI Systems. OLI Systems has combined the installation of the OLI Engine 9.2 (and later) for all the various versions of the OLI Engine in Aspen Plus. Prior to version OLI Version 9.2, there was a separate installation file for Aspen Plus V7.3.2, V8.0, V8.6, etc. Now, the installation is combined into a single package.
If multiple version of Aspen Plus are installed, you can link all of them using the OLI Alliance Software Config Tool located in the Start menu under All Programs -> OLI Systems -> OLI Engine x.x for Aspen Plus -> Tools. Click on the Link All button to link to the desired version of OLI.
The OLI Chemistry Wizard will guide you through the specifications required to create a chemistry model (.mod) file and its associated property database (.dbs) file for use with an OLI calculation engine. At the end, you can create an Aspen Plus backup (.bkp) file to use as a starting point for a simulation in Aspen Plus.
The Aspen Plus backup file will use the OLI Property Method and include the chemistry reactions on the Reactions | Chemistry forms. Some property parameters will also be added on Properties | Parameters forms. These parameters should not be modified.
Put the .bkp file and the .dbs file in one directory and run. The .dbs file is linked automatically since it has the same name as the Chemistry.
Keywords: None
References: None |
Problem Statement: I have developped a fairly convoluted user unit operation model. When I run the simulation, Aspen Plus reports a severe fortran error in thermodynamic calculations, but I can't spot what might be going wrong.
The error message in control panel is:
Block: B1 Model: USER
*** SEVERE ERROR
FORTRAN INVALID OPERATION ENCOUNTERED.
The error message in history file is:
*** SEVERE ERROR WHILE EXECUTING UNIT OPERATIONS BLOCK: B1 (MODEL: USER)
(FPEPRT.8)
FORTRAN INVALID OPERATION ENCOUNTERED. | Solution: Aspen Plus checks for numerical exception (e.g. division by zero, argument out of range) and report those as severe error as shown above. We do our best to prevent numerical exceptions in our own code, but we believe it is still a good idea to report such errors.
A side effect is that if a numerical exception is encountered in user code, which is then calling some subroutine of Aspen Plus (e.g. physical property monitors, etc), the error will be reported incorrectly as if it was occurring in Aspen Plus code. This can of course be quite misleading. To trap this type of error quite efficiently, do the following:
1. Compile your user subroutines with ASPCOMP *.f dbg
2. Add to the input file the following paragraphs:
SIM IAP=1
DIAGNOSTICS
HISTORY SYS-LEVEL=8
DEBUG fpcontrol=1
3. Run the simulation with ASPEN yyy zzz (where yyy is the name of the input file without the inp extension and zzz the run ID
4. At the IAP prompt, type GO
5. When the numerical exception is raised, Aspen Plus will crash and start the debugger, pointing the line of code which triggered the error.
Keywords: None
References: None |
Problem Statement: I have not found chain-size distribution on stream Results | Poly curves sheet even though Polymer ID is specified on Components | Polymers | Distributions form. Chain size e distribution shows zero on Poly curves sheet. | Solution: The method to track chain length distributions is not valid for all types of reactions. The method assumes that polymer molecules are stable once they are formed, therefore, it is not valid for reversible living polymerisation. It is supported by: Free-Radical, Ziegler-Natta and Emulsion reactions. It is not supported by: Step-Growth, Segment-based and Ionic reactions.
Keywords: Free-Radical, Ziegler-Natta, Emulsion reactions, Step-Growth, Ionic reactions.
References: None |
Problem Statement: I am simulating a polycondensation reaction in CSTR, my reaction type is step-growth. Can I get the Molecular Weight Distribution (MWD) plot in the product stream? I was told that step-growth reaction mechanism is not fully developed in Aspen Polymer Plus; therefore, MWD plot is not available in it, is that true? | Solution: The molecular weight distribution (MWD) charts are not supported for IONIC polymerization and STEP-GROWTH polymerization in Aspen Polymers because these are both living polymerizations. The molecular weight distribution charts can be generated for the other types of polymer reactions.
The technical mechanism we use to calculate the molecular weight distribution, the method of instantaneous moments, assumes that the polymer molecules generated at each instance in time are conserved. This is not true for living polymerization schemes where the molecules formed at one point in time can be changed later by reverse reactions.
The step-growth reaction mechanism is fully developed in Aspen Polymers Plus. Aspen Polymers Plus supports reactions for all types of condensation reactions. There are a number of application example files that illustration the different reaction mechanisms.
Table 1. Polymerization reaction models on Aspen Polymers Plus library (C:\Program Files\AspenTech\Aspen Plus VX.X\GUI\App\Polymers)
File name
Polymer
Reaction Mechanism Type
hdpe.bkp
HIGH-DENSITY-POLY-ETHYLENE (HDPE)
ZIEGLER-NATTASolution
IonicSB.bkp
STYRENE-BUTADIENE-RUBBER (SBR)
IONICSolution
ldpe.bkp
LOW-DENSITY-POLY-ETHYLENE (LDPE)
FREE RADICAL
nylon6.bkp
NYLON-6
STEP-GROWTH
pmma.bkp
POLY-METHYL-METHACRYLATE (PMMA)
FREE RADICAL
pp.bkp
POLY-PROPYLENE (PP)
ZIEGLER-NATTA GAS-PHASE
ps.bkp
POLY-STYRENE (PS)
FREE RADICAL
sbd.bkp
GENERIC-POLYMER-COMPONENT
EMULSION COPOLIMERIZATION
Keywords: Molecular weight distribution, step growth, free radical, ionic
References: None |
Problem Statement: Is it possible to open newer files in older versions of Aspen Plus? For example, is it possible to open a V7.1 file in Aspen Plus 2006.5? | Solution: No, this is not possible.
However, starting with version V7.2, Aspen Plus will allow you to open backup files from newer versions, with a warning that features not supported in this version will be lost in doing so.
Keywords: None
References: : CQ00391391 |
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