PRO/II Flash Point Calculations and Results

Flash point can be calculated by the Nelson method (FLPOINT=NELSON) or by the Pensky-Martens method (FLPOINT=API).  Nelson is the
default.  The designation of the calculation method is given on the thermo METHOD statement.  See chapter 27 of the PRO/II Keyword Input Manual. 

Flash point is printed in the refinery processor stream report.  It is also available for user defined formats for stream reports.  You can also retrieve it with a calculator.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Top distillation column simulation posts on www.simulationots.blogspot.com

Over the history of this blog we have posted many times on distillation columns, and how best to simulate them. Below is a collection of those blog posts.I hope that you find them useful. Most of the post are specific to PRO/II, but are applicable to process simulation software in general. 

• What is ALPHA in distillation column algorithms?
• 10 Most Common Pitfalls in Process Simulation #9: Assay Pseudo-Component Development
• Initial Estimates for Columns in PRO/II
• What are the differences between the Initial Estimate Generators (IEG) (CONV, REFI, SIMP, CHEM)?
• What are the major differences between the rigorous distillation column algorithms?
• Which column algorithm should I use for my application?
• When should the shortcut column be used? What information is obtained?
• Import PRO/II Column Data into KG-Tower
• Attaching a Heat Exchanger to a Column
• Column with an External Reboiler
• Adding rigorous heat exchangers to columns in PRO/II
• How do I set up a column spec or variable that requires a mathematical operator
• Column Pumparound duties in PRO/II
• Here are the answers to your distillation questions (Answers to customer questions on the blog)
• Crude Column Optimization Webinar Recording

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Stream Splitting using Stream Calculator Unit-op

The stream calculator in PRO/II is a flexible unit which allows you to blend any number of feed streams and produce products with defined composition and thermal condition




1. Select Stream Calculator from the Utilities tab of the PFD Palette, place it on the Flowsheet and connect feed and product streams to it

2. Double click on the Stream Calculator and enter the required the Product specification, Overhead & Bottom product Thermal Conditions

3. The Product specification is Mole fraction of N2 to C3 in overhead = 1.0, and IC4 to C6Plus(Petrocomponent) in bottom stream equal = 1.0. Please see the results table below:

Feel free to contact SimSci-Esscor Technical support if your require any further information or if there is anything specific you would like to know about

Submitted by:

Saher S. Jasvi
Tech. Support for SimSc


About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Pure-component data and their affect on K-values

Pure-component data and their affect on K-values

• For liquid activity coefficient (LACT)  methods such as the NRTL method, vapor pressure data for the pure components affect the vapor-liquid equilibria;
• For equation of state (EOS) methods such as SRK and PR, the K-values are affected by the critical temperature and pressure, the acentric factor, and the alpha formulation of the pure components.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Pseudocomponents generation from ASTM curves

How are pseudocomponents obtained from ASTM curves?

The following steps are performed by PRO/II:

- The assay data is converted to a TBP at 760 mm if necessary.

- The TBP curve is fit by a cubic splines or other curve fit.

- Substitute the front part of the curve with light ends if available.

- The LV % for each temperature cutpoint is determined from the curve.

- To determine the NBP of each cut, the temperature curve is integrated between the starting and ending LV % of each cut.  The resulting integrated area under the temperature curve is divided by the total LV % for the cut.  Thus the NBP is weighted average TBP of each cut.

- The API gravity is determined from the average gravity which is supplied in the input file.  Constant Watson K is assumed.  The entire TBP curve is integrated to get the average TBP (NBP) for the entire curve.  Then the Watson K is determined for the whole curve.  It is straightforward to calculate the specific gravity for each cut from the constant Watson K and the known NBP for that cut.  If user data is available, then it is used instead.

- The MW of each cut is determined from the NBP and API gravity, using the correlation shown in Figure 2B2.1 of the API Technical Data Book.  If user data is available, then it is used instead.

- The NBP, API gravity, and MW for each pseudo-component is adequate information to determine all other properties that PRO/II requires.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Toolbar Customization in PRO/II

To customize the toolbars in PRO/II, right click in the toolbar area and you will get this menu –

Clicking on one of the listed toolbar groups will turn it off, removing it from the toolbar. Clicking on “Customize” will bring up the customization dialog window –

To add a your own toolbar, click on the “New” button and give the toolbar a name. Then click on the “Commands” tab, select the category you wish to use, and then drag the command icons into the blank toolbar (outlined in red below). An example toolbar with all the draw commands dragged across is shown below as well.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Column initial estimates in PRO/II

Good initial estimates for recycle streams and columns should aid model convergence. From PRO/II 7.1 onwards, users can update their recycle stream estimates, in a solved model, by selecting the Update Recycle Stream Initial Estimates from the Input menu. All recycle streams will be updated with solution data.

Column initial estimates can also be generated/updated from a solved model. The column initial estimates can be updated by either by selecting the Update Column Initial Estimates from the Input menu; or by right clicking on the column and selecting the Update Column Initial Estimates option. If used, the Update Column Initial Estimates option, will use solution data for heater/cooler duty estimates and provide column temperature, net vapor and liquid rate profiles.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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PRO/II Keystroke shortcuts

The latest versions of PRO/II allow you to alleviate the stress on your mouse clicking finger as most menu items can be accessed by keystrokes. The menus can be accessed by hitting the
Alt key with the first letter of the menu name, for example Alt-F for the File menu (note the Output menu is Alt-U). The key letter for individual menu items is underlined, so for example hitting Alt-I, T will take you to the Thermodynamic data entry window.


Individual keystrokes can be used for zoom control and certain menu items, such as some edit commands, can be accessed by hitting the Control key and a key letter, for example Ctrl-R shortcuts Restore Input Data on the Input menu.

Many right mouse click menu items can also be accessed by key letter once the menu is brought up.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Pasting stream information into PRO/II

Composition data for process streams is often kept in Excel spreadsheets. When streams contain many components, transferring this data from Excel to PRO/II can seem arduous; however, this data can be transferred easily and accurately into PRO/II using standard Windows Copy/Paste functionality. In Excel, simply select the cells containing the composition data and type <CTR>-C; then open the PRO/II stream, click in the cell for the first component and type <CTR>-V. The composition data will be pasted into PRO/II starting at the first selected cell and continuing until the data is exhausted or the stream data is completed (Note: take care to use the same component order in both Excel and PRO/II).

This method can be used to transfer assay data, tabular data, compressor curves and other properties from Excel to PRO/II. In cases where the copied data extends beyond the default table size in PRO/II, the tables can be re-sized automatically.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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User Added Subroutine (UAS) in PRO/II

What is needed to make a User Added Subroutine(UAS)?
1)  UAS/PDTS version of PRO/II

2)  Fortran compiler appropriate for your
hardware, and compatible with the compiler used to compile PRO/II.

3)  Fortran compiler - see note below

4)  User Fortran code for UAS

5)  Extra disk space for compiling and linking

6)  Process UAS manual

7)  Current Installation Guide for your hardware

An update on User Added Subroutines (UAS).

The post a couple of days ago on User Added Subroutine was a bit confusing about the choice of FORTRAN compiler.  The latest PRO/II version (9.2, released May 2014) uses Intel Visual Fortran version 12.0.  This compiler or newer (standard or profes­sional editions) is a perfect fit for UAS.  This compiler is compatible with Net 2005 and Net 2008 architectures.

UAS is a great way to increase the capabilities of PRO/II by allowing user to create special thermodynamic methods or properties or to create proprietary unit operations.  Do you have an old reactor written in your company in FORTRAN 20 years ago?  You can attach it to PRO/II via UAS. 

For more information read the PRO/II documentation found in your installation: User Added Subroutines User Guide.  Or call our Support group to help you creating your very first UAS.  

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Compressibility factor (Z) calculation in PRO/II

How is the compressibility factor (Z) calculated in PRO/II?

There are two calculations for the compressibility factor Z.  Both can be found in PRO/II output reports, but only one has any physical meaning.  The Z from density calculation is:

Z = PV/ rho T

where rho is actual density.

The Z from K-value is:

Z = PV / rho T

where rho is "density" calculated during the K-value calculations.  This rho is an intermediate result from the EOS calculations and in general is not a good value for the actual density.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Vapor phase determined in VLLE calculations for DEWPT flashes in PRO/II

How is the vapor phase determined in VLLE calculations for DEWPT flashes?

One vapor is calculated for each liquid phase and the vapors are combined to one vapor phase.

The VLLE flash (no matter if dew-point or bubble-point or any other type)

solves the liquid-liquid equilibrium in the inner loop. This means that

once the equilibrium compositions of the two liquid phases are found, they

are used to calculate the vapor - liquid K-values. A very simplified

logical scheme of this algorithm is as follows:

1. Solve the LLE equations for xliq1(i) and xliq2(i) (i denotes component i).

2. Get two sets of vapor - liquid K-values. One set is obtained by using

xliq1(i) and the other set is obtained by using xliq2(i). Let's call

these two sets K1(i) and K2(i)

3. Combine the two sets of K-values into a single vapor-liquid K-value

according to the relation:

 

        K1(i) * K2(i)

K(i) = ---------------------------------

       frac_liq1*K2(i) + frac_liq2*K1(i)

 

In this way, only one vapor composition is obtained.

 

Therefore, the customer will easily obtain the compositions of the two liquid

phases that are in equilibrium with the vapor (provided that the

liquid - liquid phase splitting occurs at his conditions and the thermo model

is capable of reproducing it). If the same parameters are used for VLE and LLE

calculations, the obtained three phases are exactly in thermodynamic

equilibrium. If different parameters are used for VLE and LLE (which is

frequently done to improve the fit to experimental data), the thermodynamic

equilibrium in the three-phase system is approximate, but the algorithm

gives the best approximation.



About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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Join SimSci-Esscor related groups on LinkedIn

Join SimSci  related groups on LinkedIn

• SimSci (245 members - and growing rapidly)
• PRO/II Users Group (1,074 members - our largest and most active group)
• PIPEPHASE Users Group (69 members - our smallest group - but with highly dedicated members)
• DYNSIM Users (336 members - be #337)
• ROMeo Users (668 members - - think of all the insight that is shared in this group)

Which goups are you going to join?

Or connect with me (Joseph McMullen) on LinkedIn - I regularly post updates for all SimSci software!
If you have an idea for a blog post, please let me know!

All groups have discussions from users, new release announcements, and technical tips!

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Predicting Transport Properties for Aqueous Electrolyte Streams

Guest Blogger John Cunningham, SimSci Technical Support

The default transport Property methods in SimSci software are essentially an assortment of mixing rules for the transport properties stored for each component in the library.

As shown in this Table from our Reference Manual, the mixing rules are quite simple:



While this approach is quite suitable for organic liquids you can run into trouble for components that dissociate in water. Consider a mixture of NaCl, with a melting point of 1073K and water. It would be inappropriate to extrapolate the properties of liquid or molten NaCl nearly 800 K then attempt to mix this extrapolated value with the water value and expect a meaningful number.

OLI Systems a long term SimSci technology partner has addressed this concern with their new mixed solvent electrolyte (MSE) approach. They have validated methods to predict viscosities, thermal conductivities and surface tension for these types of mixtures. Shown here for example are the values for a 5 molal KOH solution at atmospheric conditions:

MSE licenses are available from your Invensys commercial representative.


About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.



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Download Whitepaper on Processing Heavy and Extra Heavy Oils

Here is a sample of the white paper:

Introduction

The world’s energy industry has followed the availability of easily attainable and economically feasible supplies for the oil segment that has moved towards heavier feedstock. The earlier extraction, accessibility, transport and processing centered around lighter crudes with characteristics that could be uniformly and reliably processed in refineries using a stable of proven technologies is no longer possible. As those lighter crude supplies have become exhausted or more difficult to obtain, demand from emerging nations such as India and China has strained the supply chain. Because of their explosive growth, these and other countries experiencing economic growth are usurping an increasing amount of the existing supply of conventional crudes while investing in supplies of heavier sources as well. Heavier crudes have unique physical properties that often present costly refining challenges. Efficient processing solutions require a thorough understanding of the crude’s characteristics and operating behavior. Those involved in heavy or extra heavy oil refining must decide what they have and how they should process it.

Download and read the full white paper here: Whitepaper on Processing Heavy and Extra Heavy Oils

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Column Pumparound duties in PRO/II

How are Column Pumparound duties determined in PRO/II?

Pumparound duties are fixed implicitly when the user fixes the rate and the return temperature or DT.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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PRO/II RVP calculation methods

What are the differences between the RVP calculation methods?

There are six Reid Vapor Pressure (RVP) calculation methods in PRO/II:

APINAPHTHA - The RVP is obtained from a nomograph in the API Databook (Figure 5B1.1, pg. 5-29) which relates the RVP to the slope of the ASTM D86 distillation curve at the 10% volume point and the temperature. This method is useful for gasoline mixtures.

APICRUDE - For this method the TVP is determined first, and then the RVP is obtained from a nomograph in the API databook (Fig. 5B1.2, pg.5-31) which relates the RVP to the temperature and the TVP. This method is useful for crude oils.

P323 - This is the method used in PROCESS. It is obsolete now, but is still included in PRO/II for comparing results with PROCESS. Dry air is added to the liquid mixture, sealed, and allowed to equilibrate at a temperature of 100 F. The measured pressure of the sample is then subtracted from the atmospheric pressure to obtain the RVP in psi. PRO/II rigorously simulates all steps in this method.

D323 (wet method) - This 1982 ASTM method is again rigorously simulated by PRO/II. This method mixes the liquid hydrocarbon stream with dry air and liquid water. The resultant mixture is sealed, allowed to reach equilibrium, and the pressure in the chamber measured at 100 F. The RVP in units of psi is obtained by subtracting the atmospheric pressure from the measured pressure. (See article #1875 in the NATS article database.)

D4953 (dry method) - This 1991 ASTM method is similar to the D323 method, except that no liquid water is added to the mixture. However, the air sample added is assumed to be saturated with water vapor. This method is useful for gasolines containing oxygenates such as alcohols, which separate out with water.

D5191 - This is based on the 1991 ASTM-D5191 method. Sample is evacuated. Applicable for volatile liquid petroleum products.

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

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New File on Start up in PRO/II

How do I configured a new file to open when PRO/II starts?

With this option every time PRO/II is launched it will open a new file, otherwise by default PRO/II won’t open a new file on launch.

1. On menu bar go to Options > New File on Start up

About PRO/II: PRO/II is the major product in the Process Engineering Suite (PES). This process simulation software optimizes plant performance by improving process design, operational analysis, and performing engineering studies. It is designed to perform rigorous heat and material balance calculations for a wide range of chemical processes. PRO/II allows users to evaluate the use of heat integration with case studies, rigorously evaluate process improvements with the help of a process flow diagram (PFD), or model crude distillation units. PRO/II offers a wide variety of thermodynamic models to virtually every industry and is incredibly cost effective, decreasing both capital and operating costs.

Technical Support: As always, feel free to reach out to your local technical support team for more information.

Read More

Join SimSci-Esscor related groups on LinkedIn

Join SimSci-Esscor related groups on LinkedIn

• SimSci-Esscor 
• PRO/II Users Group 
• PIPEPHASE Users Group
• DYNSIM Users
• ROMeo Users

All groups have discussions from users, new release announcements, and technical tips!

Read More

Join SimSci-Esscor related groups on LinkedIn

Join SimSci-Esscor related groups on LinkedIn

• SimSci-Esscor 
• PRO/II Users Group 
• PIPEPHASE Users Group
• DYNSIM Users
• ROMeo Users

All groups have discussions from users, new release announcements, and technical tips!

Read More