Installation Notes
These notes are intended to help you to install and get started using the ProTreat application.
Getting Started
The ProTreat simulation package is a set of Win32 applications and requires Microsoft Windows NT, 2000, ME, XP, Vista, Windows 7, Windows 8.1, Windows 10 or Windows 11 to run.
The package consists of a hardware security key (TimeHASP or NetHASP), your HASP Key ID and these installation notes. The ProTreat software can be downloaded from the licensee area of the OGT website (https://www.ogtrt.com). To download from the web site, you will need the Key ID of your HASP security key (contained in the key's memory, and is not printed on the key) to gain access to the download and other support pages. Your Key ID has been provided with this package.
If you have already installed a previous version of ProTreat prior to Version 5.4, first uninstall the previous version through the Windows control panel Add-Remove Programs feature. When the download completes, double click the icon placed on your desktop (or in the directory in which you instructed that the download be placed). This will extract the file Setup.exe. When you double click on Setup.exe, ProTreat will be installed on your machine (you have complete control of the drive and directory you would like to use - the XP Legacy default is C:\Program Files\ProTreat). For Windows 7 and Vista or later operating systems, the setup file should be executed by right-clicking and selecting the Run as Administrator option to circumvent the need to confirm changes to the system. ProTreat will be installed into the X86 Program Files directory of Windows 7 machines by default.
When applicable, there may be a patch file available named PTEngWin_v_X.XX_XX.zip that you will also need to download after installing ProTreat on your machine. Extract this file into your ProTreat directory and use the new file from the patch you have downloaded to replace the original existing file.
For machines that have not had previous versions of ProTreat installed, an additional step is required to install the HASP security drivers so that the machine will recognize the security key. In the directory where ProTreat was installed, e.g. C:\Program Files\ProTreat, find and double-click the file HASPUserSetup.exe. This will launch the HASP driver installation for the HASP key. When you wish to run the ProTreat application, the HASP key, which protects your software from unauthorized use, must be present in your computer's USB port (for a USB device). If the ProTreat application is to be run from a server, please refer to the server installation notes for additional steps in order to be able to launch ProTreat.
Template Files
To circumvent some of the work of generating process flow diagrams, several commonly used flowsheet templates have been placed in the \…\Templates subdirectory. Template files have blocks and streams drawn on the flowsheet, but still require the user to enter values before they can be run. Templates have the file extension *.ptp and should be saved as *.ptd files before data entry and running. The template files include amine, caustic treating, dehydration, and sulphur process flow sheets.
Example Files
To allow you to start using ProTreat right away, there are example files stored in the \...\Examples subdirectory. Example files are *.ptd files which are fully defined and ready to run. Example files cover several processes typically simulated using ProTreat.
To avoid operating system complaints, templates and examples should be resaved into a non-operating-system folder prior to running the flowsheet.
A Simple Simulation Case
The following is a description of a standalone absorber simulation. Before starting a ProTreat simulation, it is suggested that you use My Computer to create a Work directory as a subdirectory of the ProTreat main directory. This step is almost essential for Windows 7 and Vista users due to the new Windows User Account Control feature. Then, use the ProTreat icon on the desktop or Start Menu to start the ProTreat application. From Setup on the menu bar, choose Preferences and enter the name of your work directory either by typing it or via the Browse button. Use the check boxes to select the options you want. If you intend using templates, you can also Browse to the \…\Templates subdirectory and make it the default directory for retrieving templates.
ProTreat automatically is installed with a default set of colors assigned to the various unit operations blocks. If you would prefer other colors, select Setup from the menu bar, choose Set Block Colors. This brings up the Block Colors dialog which you can use either to set the color of each individual unit operation block type, import a pre-selected set of colors from the PtColors.ini file or turn colors off altogether for black-and-white printing, for example. Colors make flowsheets a lot easier to read and we highly recommend using color.
If you decide to keep a log file of the simulation, you can enter the name of the text editor of your choice to view this file (default editors are Notepad and Wordpad). A log file is a detailed audit trail of the simulation's execution on a tray-by-tray, column-by-column and flowsheet loop-by-loop basis. Because for large problems this file can become extremely large, it is suggested that you do not keep a log file unless the particular problem is proving troublesome to solve and you want an execution record to study after the fact.
rom File on the menu bar select Template > Open Template, and navigate to the \…\Templates directory if you have not already set up the default templates directory. Select and open the file #A9 - MDEA Absorber.ptp. Template files are in a read-only file location, so before proceeding perform a Save-As to put the file in a working directory of your choice, changing the file type to a Drawing File (*.PTD). Note: The template files that accompany ProTreat have US units by default. If you prefer to have templates with SI, metric, or some combination of units, change all the units in whatever file you are using, and save it as a template file with another, different name. If you opt to start with a blank screen and draw your own flowsheet, you must select the units before anything is drawn on the flowsheet because, once a block or stream is placed on the flowsheet, the data input units are fixed. However, output (reporting) units can be changed and saved at any time. Flowsheet units selections are accessed by choosing Units > Unit Manager from the menu bar. Your selection can be saved as the new default units set, and the new units set can be saved under a unique name for future use in other simulations.
Chemical components are selected by choosing Flowsheet Components from the Setup menu and either double clicking on the desired components, or selecting them and using the Add and Remove buttons in the Select Components dialog. Water is always a flowsheet component and it appears automatically in the components list for the flowsheet. As an example, we will simulate removal of carbon dioxide and hydrogen sulfide from a methane-ethane mixture using a DEA-promoted MDEA solvent. These are the flowsheet components. Global data are set via the Global Data command on the Setup menu on the menu bar, and they include local atmospheric pressure (useful for low-pressure treating plants at high elevation), the standard temperature (usually 60 oF for gas treating), the default thermodynamic model together with the convergence tolerance and the maximum number of thermodynamic iterations allowed per calculation. The default values are usually adequate.
If your license allows access to the physical solvent DMPEG or Dehydration, Hybrid Solvents, or Sulphur, additional thermo models are available. OGT Gas Treating is used for amine systems. Physical Solvents is designed for use with physical solvents and dehydration. Hybrid Solvents is used for aqueous amines in a physical solvent such as sulfolane. If your license includes sulphur then the Sulphur thermo model is also available. It is important to select the right thermo model for your chemical system. Blocks on the flowsheet include a specification where the default global thermo model can be overridden. Use a Thermo Transfer block to transition between thermo models if necessary.
At this point you can complete entries under Reports on the menu bar, or you can wait until completing all data entry, or even until after the simulation is run. Reporting options allow you to select what is reported and the reporting units.
Inlet Streams
Double clicking on the block "Lean Amine" brings up the Lean Amine dialog box for data input. The name of this inlet block can be changed to "Lean" (or any name you want), and we select the composition option for stream data. On the Parameters tab enter the lean solvent temperature (110°F), its pressure (300 psig) and its flow rate (200 USgpm). Note that other units can be applied against any input quantity. The flowsheet components contained in this stream (the stream components) are selected from the flowsheet components source list by clicking the Components button. We will select H2S, CO2, MDEA, DEA and water as components from the source list, omitting methane and ethane from the components list for this inlet solvent stream block. The composition for inlet stream 2 (Inlet-2) is entered via the Component Concentration dialog which is displayed by clicking the Values button on the Parameters tab. A double click on Carbon Dioxide in the components list brings up the dialog for data entry for that component. We enter the value 0.01 and select the unit Loading. Clicking OK returns focus to the Component Concentration dialog. We repeat this sequence of steps for each component, entering 10 wt% for DEA, 0.001 Loading for H2S and 40 wt% for MDEA. Finally, since this is a solvent stream, we select the radio button opposite "Is Remainder (Solvent Streams Only)" to indicate that the rest of the solvent is water.
The entire process is repeated for the "Feed Gas" stream in the template drawing. We assume there are no amines in this stream. We will treat 15 MMSCFD of gas containing 10 mole% CO2, 2 mole% H2S, 80 mole% methane and 8 mole% ethane, water- saturated at 80°F and 310 psig. Note that in the Component Concentration dialog these add to 100% (as they would in a typical GC analysis) and the water content in this case has been entered as 100% saturation.
Column Data
Double clicking on the column icon brings up the Column Data dialog. On the Configuration tab the two check boxes Has Condenser and Has Reboiler allow this column to be converted into a reboiled regenerator with overhead condenser. We will leave these boxes deselected because in this example we are modeling an absorber. The column contains a single section (i.e., a single group) of generic valve trays. A wide range of other tray and packing internals is available in the drop-down list. Clicking on the Data button brings up the Tray Data dialog which includes places for entering the number of trays (20), the tray spacing (2 ft), the number of liquid flow paths (passes), the height of the overflow weir (3 in), and a foam derating factor (0.85). Clicking OK enters the data into the simulation model and returns control to the Configuration tab. Clicking the Size button allows the method and parameters for tower sizing to be specified. We will opt to calculate the diameter based on 70% vapor jet flood and 70% downcomer flood. Finally, clicking the Pressure button brings up the Column Pressures dialog. The first Pressure is taken to be known (300 psig) above the top tray—the pressure drop over the tower will be calculated by the simulation.
ProTreat offers the OGT Gas Treating model for amines. If you have a license to use physical solvents, there will be an additional thermodynamic package, Physical Solvents. For an amine column use OGT Gas Treating; for a column using physical solvents use Physical Solvents.
Exactly where streams enter and leave the column is specified on the Streams tab. In this example, the outlet streams Outlet-1 and Outlet-2 have been attached to the tangent ends of the tower. This automatically indicates tower top and bottom connections, respectively. Under the Streams tab, select 1 from the Streams list and click Connect. This brings up the Tray Section Feed Stream Data dialog where we specify that Stream 1 connects below the bottom tray (tray 20), and Stream 2 enters the tower above the top tray (tray 1).
The Initialization tab will be discussed later (see Helpful Hints – Column Initialization later in this document).
The Report tab allows you to select the components whose tray-to-tray profiles you wish to view, either in a printout of numerical data, or graphically. If you forget to enter these data before the simulation is run they can be entered later by selecting the column and right clicking outside the column border. This will display a popup menu and clicking on Report Options will allow you to select the components to be reported for this tower.
On the Convergence tab, the desired solution tolerance is set as a maximum relative error on the acid gas compositions anywhere in the tower and the maximum tower iterations is also set, in this example at 0.001 and 50, respectively. In cases where convergence proves difficult, damping can be applied to the tower solution process. More will be said on this below. All through the data entry process, on-line help relevant to the open dialog box, is available by clicking the Help button displayed in the dialog.
This completes data entry for this simulation. The file should now be saved. You can check the validity of the entered data before starting calculations by choosing the Ambulance button on the Toolbar but, in any case, the ProTreat GUI always will automatically check for obvious errors before allowing calculations to start. You always have the option to run the simulation regardless of the data status. Choosing the Run button on the Toolbar starts calculations and you will be prompted to save the file if you haven't already done so.
Results & Reports
While the simulation is being run, a small graphical display of the column temperature profile is shown and to its right there is a column of tower segments. The position of the white bar within this column of tower segments indicates the segment being solved. On the menu bar there are options for viewing column convergence data (Column), the sequence in which blocks are being solved (Sequence), flowsheet loop convergence progress (Recycle), and solver loop convergence progress (Solver).
Once the model has been solved, the results file is automatically loaded into memory. You may then view results for the whole flowsheet by clicking anywhere on the flow diagram away from blocks and streams. Double clicking on any stream or block will display the results for that stream or block. To view graphical tower profiles of temperature, pressure, composition and flow rates, first select the column block whose results you wish to view (by clicking inside the column graphic), then select Manage Graphs from the Reports menu on the menu bar. This will bring up the Manage Graphs dialog. Clicking the Define button brings up the Define Graph dialog which you can use to specify exactly what variable you want to plot, its units and the scale (linear, logarithmic, or linear with manually set upper and lower limits). Graphs can be added to the Manage Graphs list box for printing as part of the simulation report. Various reporting options are available from the File menu by selecting Print.
Helpful Hints
Below are several hints that may be useful in setting up simulations or helping simulations to converge. Additional hints are posted and updated periodically on the OGT web site in the Licensee Area.
Reporting Column Components
The components to report as part of a column report can be specified on the Report tab of the Column Data dialog before the simulation is run. However, if you forget to select the components to report before running the simulation, you can select them afterward by first selecting the column icon (by clicking anywhere inside it), then right clicking outside the icon box and choosing Report Options from the popup menu.
Column Initialization
On the Initialization tab in the Column Data dialog, the default selection is Initialize from last run (if available). This default setting allows previously calculated column results to be used to initialize subsequent runs – a great time saver in most circumstances. In the unusual circumstance that alternative initialization is desired, the user may choose to Initialize from heuristics or to Initialize from another file. If a column is having trouble converging the using one of the alternative initialization methods might prove beneficial. See the Help topic for Column Initialization for more details.
Damping
Although column convergence difficulty is strikingly evidenced by a Runtime Error, it can also be indicated by a meandering temperature profile, a temperature profile that moves erratically, and by some column segments in the temperature profile window remaining red even after several iterations through the column. This can happen either without damping or with insufficient damping being applied. These problems are often caused by the solution procedure trying to progress too fast and overshooting. One way to handle this is to dampen the step size for the first few column iterations, and usually only for the first time through the column in a recycle flowsheet. On the Convergence tab in the Column Data dialog you can type a value for the Damping Factor and the Damped Iterations (number of damped column iterations) for which it is to be applied. Note: if you are going to use damping, you must apply it to at least the first loop or cycle even if the flowsheet contains no recycle streams. The damping factor is the fraction of the normal, calculated step that is actually applied in the solution process. Thus, for a damping factor of 0.1, only 10% of the calculated solution step is applied during the first "n" column iterations. Typically, damping factors range from 0.25 down to perhaps 0.05 or even 0.01 and damping is applied to the first 5 or 10 iterations – small damping factors apply to extremely hard-to-converge cases. Of course, one can always apply both damping and restarts and thereby virtually guarantee a solution to most problems.
Regenerators with Reflux Ratio or Stripping Ratio Specifications
When regenerators are given a reflux ratio or a stripping ratio specification, the ProTreat simulator solves the regenerator a number of times using estimated reboiler duties to bracket the reboiler duty required to meet the specified reflux ratio or stripping ratio. You should allow for this extra computation by permitting at least 100 iterations for a standalone regenerator and perhaps 50 - 100 iterations when the regenerator is in a recycle flowsheet. Regenerators with a reboiler duty specification usually converge in 20 or so iterations although more may be required if the column is only lightly reboiled. The safe approach is to over-specify the maximum allowable iterations because the ProTreat simulator will use only what is necessary to converge the column. However, in a recycle flowsheet, maximum column iterations can be reduced because each column is solved several times as the calculations cycle around the various flowsheet loops. Unresolved residual error in any loop will be reduced on the next loop.