Stock Mixtures
A stock mixture is simply a mixture of pure components and/or other stock mixtures with a given composition (in mass or molar percentage). Typically stock mixtures are used to represent materials that are provided and consumed by a process ‘as-is’ in the form of a mixture. Examples of such process consumables might be buffers, acid solutions, base solutions, etc. Stock mixtures can be used to initialize process input streams (see Composition & Related Properties of a Bulk Input Stream) or they can be employed directly by an operation (without being present on any stream) as special agents (e.g. in a ‘Clean-in-Place’ (CIP) operation as a cleaning agent, in a ‘Gas Sweep’ operation as a sweeping agent, etc.) The most important property descriptions that you need to provide for a mixture is its composition and its price (see Stock Mixture Properties). In order to facilitate the reuse of mixtures without having to describe all their properties from scratch each time, the application keeps a list in a stock mixture databank (see Databank of Stock Mixtures). Before a stock mixture can be engaged by your process simulation, it needs to be introduced (registered, see Stock Mixture Registration) and be given a name-ID (‘Local Name’) that will be used to represent the mixture.
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Since stock mixtures can only be used as inputs to a process, they only exist to describe the composition of input streams of a process. You will never find the names of mixtures as part of the composition description of an intermediate or output stream. Stock mixtures lose their identity once they are come in contact with other mixtures or pure components. SuperPro Designer converts mixture flows into their equivalent pure component flows and performs material balances and reports results based on pure component flows and compositions.
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Stock Mixture Registration
In order to make a stock mixture available to be used as an ingredient in the composition of an input stream in your process, you must first register it. Registering a stock mixture, (just as registering a component) simply means that you introduce this mixture into your process file and provide an accurate description of its properties. You may register a mixture simply by importing it (and thereby copying all its properties) from the stock mixture databank (in the ‘SuperPro (User)’ database). Alternatively, you may introduce an altogether new mixture that does not exist (currently) in the stock mixture databank. These options are exactly analogous to options available for pure components (see Pure Component Registration).
Mixtures can be registered through the dialog that appears when you select } } form the main menu of the application (or type Ctrl+Shift+2 as a shortcut). This selection will bring up the Stock Mixture Registration Dialog. Registering a new stock mixture serves mainly two purposes:
1. Provide to the process simulation a description of all of the mixture’s properties (composition, density, price, etc.), and
2. Define a short name tag (‘Local Name’) which will be used everywhere the application needs to reference the mixture (on stream initialization dialogs, reports, etc.). Please note that each registered mixture’s ‘Local Name’ must be unique among all registered stock mixtures and pure components.
Stock Mixture Registration Dialog
This dialog appears when you select } } from the main menu of the application
The stock mixture registration dialog.
Using the interface shown in The stock mixture registration dialog. you can:
● Introduce (register) a new stock mixture into the process by importing it from a stock mixture databank.
● Introduce (register) an altogether new stock mixture (which does not exist in any of the stock mixture databanks.)
● Delete an already registered stock mixture.
● Edit the properties of a registered stock mixture.
● Deposit a stock mixture already registered in your process to the stock mixture databank so that it can be used later by you or any other member of your team.
● Transfer (copy) the physical or economic property data (kept in the ‘SuperPro (User)’) from a member of that databank onto an already registered mixture that either lacks such data or has outdated data.
● Reconcile (synchronize) the property values of a registered mixture with its values in the databank (requires that the mixture still has a databank record).
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The second column on the registered stock mixtures table shows by default the formal Name of the mixture. The user may select to display either the Name or the Company Id, by choosing the respective radio buttons located under the table.
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The Source column on the registered stock mixture table shows the original source of the stock mixture. This may be a database (Designer or User) or locally defined mixture (Local). The asterisk (*) shown next to the database name in parenthesis, indicates that the stock mixture’s properties are not identical to the properties of the original mixture in its source database. The negative sign (-) means that the mixture can not be found at all in its original source database. This may occur if you are using databases created by different users of the program.
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Every registered mixture is identified within your process by a ‘Local Name’; that is simply a short name by which this mixture will be mentioned in any input stream initialization dialogs or any stream reports related to this process simulation.
3. Select the mixture from the displayed listing.
From the databank contents list box, select the mixture that you want to pull into the process. If the name is not visible, you may scroll up or down until you locate it, or start typing the name at the top of the list box. You can list mixtures either by their (full) Name or by Company ID. If you click on “My List”, then only mixtures designated as belonging to “My List” will be shown to select from. Notice that as you start typing the name of the mixture you wish to locate, the program responds by automatically scrolling in order to find and select the first choices that matches the typed portion of the name. The mixture databank contents may be listed by any of the following indices: ‘Name’, ‘Trade Name’ or ‘Local Name’.
4. Click on the Register button.
Notice that the number of rows in the registration table will expand by one. The mixture order may change as mixtures are listed alphabetically based on their ‘Local Name’.
5. If you wish to view and/or edit any of the mixture properties see To edit the properties of a registered mixture....
6. Repeat steps 1 through 3 for all mixtures that you wish to register, then exit the Stock Mixture Registration Dialog by clicking on the OK button.
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If the mixture you are about to register requires the presence of ingredients that are not still registered, SuperPro Designer will automatically register (after the user’s approval) all such pure components and/or other stock mixtures. You cannot have a stock mixture present in a process simulation without all of its ingredients being present (registered) as well. Also, if you attempt to delete from the registration list any such ingredient (while still being used in the description of a registered stock mixture), the application will not allow it.
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1. Click on the Create New (
) button.
Fill in the fields of the New Stock Mixture Definition Dialog that comes up. Even though uniqueness of names is strictly required amongst all other mixtures in your file, it is recommended that you supply names that are unique amongst the whole ‘SuperPro (User)’ database, in case you later decide to keep the mixture and deposit it there.
2. Specify how property values will be initialized.
Before the new mixture is introduced to your process, the application needs to know how to initialize its properties. You have two choices:
(a) select another mixture to be used as source, or
(b) request that all mixture properties are set to zero.
Choice (b) will force you to visit the mixture’s properties dialog in order to provide proper values (see To edit the properties of a registered mixture...) before you exit the registration dialog.
3. Click OK.
Unless the program detects any conflicts with the ‘Local Name’ specification, the new mixture will be added to the list of registered components. If you choose to keep the new mixture definition and have it available for use by a future project, you should deposit this mixture in your mixture databank (see To deposit a registered stock mixture into the mixture databank...).
1. Select the mixture in the registration table
Locate the mixture in the registration table, and click on the row that represent the mixture. Notice that when you click on it, the whole row is highlighted.
2. Click on the View/Edit Properties (
) button
The Stock Mixture Properties Dialog will appear. From that dialog you can edit the mixture’s properties. For a complete description of the mixture properties, see Stock Mixture Properties.
3. To keep the changes you made on the selected mixture’s properties, exit the Stock Mixture Properties Dialog by clicking on OK. The changes are still not permanent. They will become permanent when you exit the Stock Mixture Registration Dialog by clicking OK. If you don’t exit the Stock Mixture Registration Dialog with OK but by clicking Cancel, any mixture property modifications you made will be lost.
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Modifying the properties of a registered stock mixture that was pulled from a mixture databank does not affect the property values of the original mixture record in the databank. It also will not affect the mixture properties of the same mixture used in simulations by others sharing the same mixture databank(s) with you.
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1. Select the mixture in the registration table
Locate the mixture in the registration table and click on the row that represents the mixture. Notice that when you click on it, the whole row is highlighted.
2. Click on the Delete the 
button.
1. Select the mixture in the registration table
Locate the mixture in the registration table, and click on the row that represent the mixture. Notice that when you click on it, the whole row is highlighted.
2. Click on the Deposit button
If the mixture does not exist in the ‘SuperPro (User)’ database currently, it will be added. If the mixture already exists in the database, the program will request a further confirmation that indeed the intention is to update the existing mixture properties in the databank. In any future project that you may need to import that mixture from the databank, the component will have the newly assigned set of values.
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Please remember that any changes in the ‘SuperPro (User)’ database as a result of any action on this dialog will be permanent and will not be reverted even if you exit the dialog with Cancel.
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1. Select the target stock mixture in the registration table.
Locate the mixture in the registration table, and click on the row that represent the mixture. Notice that when you click on it, the whole row is highlighted..
2. Select the source stock mixture.
From the contents of the selected database, select the mixture you wish to use as the source of the mixture properties.
3. Click on Phys Props or Econ Props button.
If you wish to copy the physical properties of a mixture, then click on the Phys Props button. If you wish to copy the economic properties then click on the Econ Props buttons.
1. Select a registered mixture which exists in the ‘SuperPro (User)’ database. In order for a mixture to be verified as ‘existing’ in the ‘SuperPro (User)’ database, its ‘Name’ must match exactly with one of the records in that databank.
2. Click on the Update Econ. Data from DB (
) button to update the economic properties of the registered stock mixture from the record in the ‘SuperPro (User)’ database.
3. Click on the Update Econ. Data in DB (
) button to update the economic properties of the mixture record in the ‘SuperPro (User)’ databank based on the current values of the registered mixture. Please remember that any changes in the ‘SuperPro (User)’ database as a result of this action will be permanent and will not be reverted even if you exit the registration dialog with Cancel.
Pre-Registered Mixtures
As soon as you start a new process simulation project, SuperPro Designer introduces (registers) automatically for you one stock mixture: ‘Air’. The reason that ‘Air’ is automatically introduced is because typically, all vessels are assumed to be filled with air at the start of a simulation run (before any liquid contents are transferred in). In order for ‘Air’ to be registered, SuperPro Designer also auto-registers the pure components that are the ingredients for ‘Air’: ‘Oxygen’ and ‘Nitrogen’ (see Pre-Registered Components). Note that ‘Air’ cannot be deleted from the list of registered mixtures.
Stock Mixture Properties
Stock mixtures have very few properties as they only have a temporary presence at entry points of the process. Their properties are presented for viewing and/or editing on the Stock Mixture Properties Dialog in four groups:
● Stock Mixture: IDs
● Stock Mixture: Composition & Density
● Stock Mixture: Economics
● Stock Mixture: Comments.
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A stock mixture will be considered as “Dry Solid” ingredient (when present in the composition of an input stream) if all of its ingredients are tagged as “Is Solid / Part of Dry Matter” and thus, it will have a non-zero ingredient percentage when showing compositions on dry-basis (% db). If all ingredients of a stock mixture are aqueous, then, the mixture is considered aqueous and its amount only contributes to the Aqueous flow (or amount) of the stream (or equipment content). If a stock mixture has some ingredients that are tagged as dry matter and some that are aqueous, then, the option of displaying composition on a dry basis (as well as dry solids flow, DS %, etc.) is disabled from the input stream (or equipment contents) dialog. You can visit the stock mixtures’s ID tab to see:
a) If the stock mixture is considered “Dry Solid” (all its ingredients are “Dry Solid”)
b) The “Dry Solid Content” percentage. Note, that in order for a stock mixture to be considered “Aqueous” the “Is Dry Solid” flag should be shown as ‘off’ AND the dry solid content must be 0.0%. If the “Is Dry Solid” flag is shown as “off” but the dry solid content is non-zero, then, the stock mixture is indeterminate (neither dry matter nor aqueous).
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Stock Mixture: IDs
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Name
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The formal name of a stock mixture. It is supplied when the mixture is originally introduced (either to the databank or the process file), and it cannot be edited later. It can be a string of up to 63 characters. Should be unique amongst all other mixtures and components in the databanks.
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Local Name
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The local name of a mixture is the display name (or ID) by which this mixture appears everywhere in the process (streams dialogs, operation dialogs, reports, etc.). It can be a string of up to 15 characters. It is supplied when the mixture is originally introduced (either to the databank or the process file), but it can be changed later (but must be unique). The name change cannot be done from the Stock Mixture Registration Dialog but from a a separate interface (select } } from the main menu to display the Rename Stock Mixture Dialog.
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Trade Name
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It is meant to display a name by which this mixture is widely known in the open market. It is supplied when the mixture is originally introduced (either to the databank or the process file), but it can be changed later (but must be unique). It can be a string of up to 31 characters.
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Company ID
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Often stock mixtures are identified and tracked within corporations with a company-wide tag ID number. This field is reserved to contain exactly that description. It is provided when the mixtuer is originally introduced (either to the databank or the process file), but it can be changed later (uniqueness is not required). It can be a string of up to 31 characters.
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Is Solid / Non-Volatile (Part of Dry Matter)?
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This property is always reported by the program (users cannot set it or clear it). If checked, it informs the user that all the ingredients of this stock mixture have the “Is Solid / Part of Dry Matter” tag on. If not checked, then either all or some of its ingredients are aqueous. If all of the ingredient are aqueous, the dry solid content percentage will be shown as 0%. If not, then this stock mixture, when present as ingredient in the composition table of an input stream, nullifies the option “Dry Basis”, since the program can’t place it on either the aqueous nor the dry solid category. For more information on how to activate the tracking of dry matter in a process model, see Pure Component Registration andEnable Dry Mass Options.
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Dry Solid Content (%)
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For stock mixtures that contain at least one pure component directly in their ingredient map, or indirectly in the ingredient map of one of their constituent ingredient stock mixtures, this value is non-zero and represent the percent of weight that this stock mixture (when present) contributes towards the dry solids count. For more information on how to tag a pure component as “part of dry mass)Enable Dry Mass Options.
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Stock Mixture: Composition & Density
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Composition
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The composition of a mixture described on a mass or molar basis. A mixture can be composed of pure components as well as of other mixtures. All of the mixture’s ingredients must be present in the same environment as the mixture: if the mixture is a registered mixture, then all of its ingredient must be registered in the same process file; if the mixture is present in a databank, then all of its ingredients must be present in the ‘SuperPro (User)’ database.
If the composition of the mixture is not known but the concentration of one (or more) key ingredients is (as molarity or strength in one or more components) you may find it useful to use the target concentration calculator feature available on the Stock Mixture Properties Dialog: Composition Tab.
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Density
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The density of a mixture is calculated based on a user-selected model. There are three models that users can choose from:
a) A parametric model: D (in g / L) = a + bT (T in K)
b) Assuming that the mixture will always be used in liquid/solid state, use a composition-based weighted average of the liquid/solid density estimates of its ingredients, or
c) Ideal gas law (assumes that the mixture is always in gaseous state).
The mixture’s density is only used when the mixture is the one and only ingredient of an input stream and the stream’s density model dictates to use its ingredients as source (see Stream Physical State Calculation Options).
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Stock Mixture: Economics
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Purchase Price
$/base-unit
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It can be either be provided directly by the user (on a per-unit-of-choice basis) or it can be calculated from the mixture's ingredients as the weighted average of their purchasing price. The basis units are ‘kg’ by default but may be changed by the user to any one of several choices of mass or volume units. If a a per-volume choice is made (e.g per-gallon), then to convert the price on a per-mass basis, the application will use its density model to compute the density of the material in 0 and 1 bar.
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Supplier
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Preserves the name of the most common supplier for this chemical. Kept for documentation purposes only.
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Stock Mixture: Comments
Holds any documentation that may need to be conveyed to any engineers that may use this chemical. It may convey sources for the property values, precautionary measure that need to be taken when handling this chemical, etc.
To find out how you can edit the properties of a registered stock mixture in a process, see To edit the properties of a registered mixture.... To find out how to edit the properties of a stock mixture in the databank, see Viewing the Contents of the Stock Mixtures Databank.
Synchronize Registered Stock Mixture Properties with Databank
It often becomes necessary to realign the mixture properties of materials as they exist in your process file with their records in the databanks where they originally resided. There may be several reasons for that. You may have experimented with different values for some of their properties but in the end, you realize that you were better off keeping the original values. Or, as you were developing your process simulation, some other members of your organization may have updated the database records for some of the mixtures engaged in your simulation. Sometimes, you may want to move the date in the other direction: from your mixtures as they now exist in your process file, back into their permanent records in the databank. Perhaps you experimented with slightly different values for some of their properties and as it turns out, they describe their behavior more accurately. Or, perhaps you imported their values from someone else’s ‘SuperPro (User)’ database file that is no longer accessible to you but you wish to keep a permanent record in your own databank.
This synchronization between your stock mixture objects in a process file and the databank records can be done by using two dedicated interfaces for this purpose:
a) To update your component properties from the databank records, select } } from the main menu of the application and work with the Update Stock Mixture Properties From the Databank interface.
b) To update the databank records based on the values of the mixture objects as they are currently in your process file, select } } from the main menu of the application and work with the Update Stock Mixture Properties To the Databank interface.
