It’s no secret that distillation columns tend to be more difficult to solve successfully in process simulation than most other units.  There are many reasons for this, but the following are some hints to help you get a green towe ...

Occasionally ProMax users ask how to find out how much of the reboiler duty is used for heating the rich amine liquid stream and how much of the duty is used for the acid gas desorption reaction.

Sometimes a column will not solve when the execute button is pressed, and occasionally the warnings or messages are missing, hiding or not helpful. The following are some of the most common things to check to try and get your column to begin iterations:

• Specify the Column Pressure – check the stage data, summary grouping to make certain that ...

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 ideal can have significantly diff ...

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: & ...