If problems occur during execution of an amine sweetening unit simulation, you should always first look at the Warnings list and Message Log for clues as to what went wrong. If there is too little or too much acid gas absorption, check the following:

1. If too much acid gas is absorbed, be sure the Column Type (Process Data tab) is set to TSWEET Kinetics ...

With feed streams changing, and with the ever watchful eye on the bottom line, you need to have simulation software that can help steer you in the right direction.

In 2006 Bryan Research & Engineering, Inc. and Crosstex Energy Services, L.P. published an article for Hydrocarbon Engineering titled “Steady-State Simulators are Developing a Dynamic Perso ...

Process engineers often express concern about amine reboiler temperatures being high enough to cause thermal degradation of the amine. However, thermal degradation is generally not a concern in amine reboilers heated with steam or heat transfer fluids.

In “DEA degradation mechanism,” Hydrocarbon Processing, October 1982, A. Meisen and M. L. Kennard ...

When modeling crude distillation columns, boiling point curve temperature specifications are often used to characterize products (e.g. ASTM D86 90 Volume % Cut Point Temperature). In the early stages of the model development it may be easier to monitor the product boiling point curve temperatures rather than converge on a particular specification. Once the column has been converged with r ...

Typically March in Texas is not a time to expect snow to fall; but it did. While we don’t know when we are going to have freezing water fall from the sky, hopefully we have more control over our operating units – freezing water in our sky is much better than freezing water in our gas plants.

Water content is important for predicting these freeze con ...

BR&E will be presenting a paper entitled “A Comparison of Physical Solvents for Acid Gas Removal” at the 87th Annual GPA Convention in Grapevine on March 3, 2008. This paper compares the acid gas removal ability, required equipment, and power requirements for the four physical solvents DEPG, Methanol, NMP, and Propylene Carbonate. If you would like a copy of th ...

Why does the actual volumetric flow rate in ProMax not equal the standard liquid volumetric flow rate if the stream temperature and pressure are at standard conditions?

The only time the actual and standard liquid volumetric flow rates will be equal at standard conditions is if the system forms an ideal solution. Solutions that are not idea ...

The Options.xml file specifies ProMax program defaults such as stream properties, units sets, items appearing in Tooltips, etc. Some default settings can be changed using Project Options, however, extensive changes may be inconvenient if they are to be performed for each new Project. Other default settings cannot be accessed through the ProMax program. By editing the Options.xml file, def ...

Recovery values are very useful to see on a process flowsheet.  However, sometimes you may want to display these values with a custom name.  Let us say you want to see the elemental sulfur recovery for a Claus unit.  There is a simple way to display this value as described in another blog entry.  A custom name can be assigned by defining a user defined ...

BR&E will be participating in three papers and presenting two next month at the 87th Annual GPA Convention in Grapevine Texas.  One is titled “Industrial Design and Optimization of CO2 Capture, Dehydration, and Compression Facilities” and written in partnership with HTC Purenergy of Regina, SK, Canada.  The main design and engineering factors ...

Have you ever needed to add a solver to your simulation that could calculate exchanger temperature change to achieve an Approach Temperature or End Point UA?  The ProMax Property Stencil Add-in offers what is known as a UA Wizard that will achieve the same results as a solver. Unlike a solver, UA Wizard does not require you to build a calculator. Once you attach the UA Wizard to ...

There have been many questions concerning temperature rises predicted by ProMax across JT valves and other adiabatic flashes. Depending on conditions, ProMax may predict the temperature to rise in the flash. I have created a document that explains the cause of this temperature rise and mathematically proves its existence for simple systems.

Amine systems can be tough to calculate. However, there are a few things that you can do to help out. In this post we're going to discuss a few options on the convergence tab, especially the Enthalpy Model and the Inner Loop Model.

The amine regenerator can, at times, be especially challenging. Sometimes the column will refuse to converge or will converge quite slowly. ...

What seems like an insignificant amount of ammonia in the sour feed gas to an amine unit can be detrimental to the sweetening process. Ammonia in an amine sweetening system can cause reduced absorption of acid gas, as well as greatly increased stripper condenser and reboiler duties due to build up of NH3 in the system. Corrosion in the stripper condenser loop is also a significant problem ...

The Relief Valve Sizing Analysis in ProMax calculates the Effective Discharge Area, Relief Pressure, and other parameters. This analysis reports estimation of latent heat of vaporization for mixtures (Inlet Latent Heat parameter) which may be used for other applications. This sizing analysis applies only to relief devices intended to protect unfired pressure vessels against overpressure o ...

If you are trying to find the water content or water dew point of your gas, add a “Freeze Out, Hydrate, H₂O Dew Point” analysis to the stream. The temperature of the water dew point is given, as is the water content of that stream (reported as lbm/MMSCF, pounds per million standard cubic feet).

What if there is not a number he ...

ProMax uses the arithmetic average method for calculating mixed liquid viscosity because that method is used by all of the pipeline pressure drop models included in the program (see Brill and Beggs, 1991) except the OLGAS correlations. However, the viscosity of oil/water mixtures is extremely difficult to predict. In Brill and Mukherjee, SPE, Multiphase Flow in Wells, 1999, they say: & ...

The Property Stencil distributed with ProMax 2.0 includes tools such as Copy Stream Conditions, Flow Duplicator Example, Property Calculator, Cn+ GPM Calculator, Cn+ GPM Solver Example, UA Wizard, and many others. The Property Stencil may be found in the C:\Program Files\Bryan Research & Engineering Inc\ProMax2\AddOns\Visio Property Stencil folder. To open the Property Stencil in ...

The 2.0 version of ProMax includes energy budget and recovery calculation objects that are fully customizable by the user. The recovery objects provide a summary of the project inlets, outlets, losses (due to convergence tolerances), and component relative outlet recoveries. For example, it is very easy to compute the recovery of components in any number of selected outlets relative to an ...

Plug flow reactors in ProMax can be used to model tubular flow reactors in which there is no mixing in the horizontal direction and perfect mixing in the radial direction. Kinetic information must be known and the reaction does not have to come to equilibrium. Reaction set data must be completed which includes stoichiometric equations, reaction order information for some combination of fo ...

Like the Gibbs Minimization reactor, the Equilibrium reactor in ProMax also calculates chemical equilibrium. However for this reactor stoichiometric equation information must be entered by completing the data for a Reaction Set. The required equilibrium constant may be determined by one of two options. ProMax can calculate the equilibrium constant from the Gibbs free energy or it can be e ...

The Gibbs Minimization reactor in ProMax has the advantage that stoichiometric equations are not required. Equilibrium is determined from the free energy and the heat of reaction is calculated automatically. The method is completely general and predictive. Processes which come to equilibrium or close to equilibrium may be modeled with this technique. ProMax allows the user to choose which ...

When entering components in ProMax, the components may be filtered based on chemical formula. If the exact formula is known, you may enter the formula in the field and all compounds matching that formula will be listed, subject to other filters. This is a case sensitive match and elements should be entered using their standard upper and lower case combinations. Additionally, a wildcar ...

In ProMax, color indicates the status of blocks and streams. For the user with normal vision, a red block is unconnected, a blue block is unsolved, an orange block has an approximate solution, and a green block is solved. The color blind user cannot distinguish between some of these colors and thus cannot visually determine block/stream status. ProMax includes some color scheme options wh ...

New in ProMax 2.0 is the ability to create User Value objects which are values or properties defined by the user. Related User Value objects are grouped into User Value Sets as defined by the user. Any of the predefined unit combinations present in ProMax (e.g., mass flow rate, temperature, density) may be selected for a user value. Alternatively, a custom unit may be defined which combi ...