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 ...

Multi-Sided or "Complex" Heat Exchangers are brazed aluminum plate and fin exchangers which can heat and cool up to 15 fluids simultaneously. They are commonly used in cryogenic service, both in air liquefaction and in high efficiency gas processing plants. They are composed of a large number of aluminum plates held apart by spacers which create flow channels between eac ...

In a Claus Sulfur Recovery Unit, COS and CS2 are formed in the acid gas burner and are partially destroyed in the first Claus bed (provided the appropriate catalyst is present and the temperature is sufficiently high). Equilibrium models do not adequately predict the formation of COS and/or CS2 in the burner as observed concentrations can be significantly higher than equilibrium predictio ...

BR&E announces the release of ProMax 2.0. ProMax 2.0 includes many new significant features including complete reactor suite modeling, Claus Sulfur plants, pipeline and line sizing improvements, relief valve sizing, user value objects, recovery and energy budget summaries, support for Microsoft Visio 2007 and Microsoft Windows Vista, and much more.

The ProMax 2 ...

The time has finally arrived and Bryan Research & Engineering, Inc. is proud to announce the release of ProMax version 2.0. ProMax 2.0 is a major upgrade and includes a complete reactor suite for modeling kinetic (plug flow and stirred tank), equilibrium, conversion, and Gibbs minimization schemes. We are especially proud of the ability to model Claus sulfur recovery plants throug ...

The typical Claus sulfur recovery unit includes an acid gas burner, a waste heat boiler, and sulfur condenser followed by 2, 3, or 4 catalyst bed converters for conversion of H₂S and SO₂ to sulfur. Each converter is preceded by a reheater and followed by a sulfur condenser.

Alternate or optional reactors might include sulf ...

Sulfur Dioxide and Sulfuric Acid and Acid Rain, Oh My!

What is the pH of pure rainwater? Did you say 7? If so it’s a good guess, but not actually what is falling from the sky.

Carbon dioxide in the air is dissolved into the water and then forms carbonic acid (H₂CO₃). In normal conditions, rain ...

ProMax gives its users great flexibility when designing complex towers with sidedraws and side reboilers. There are several ways to represent side draws and the user should understand the differences within the options given in ProMax.

The simplest sidedraw is one where all of the liquid leaving a given stage is drawn off, heated and returned to the stage below. Likewi ...

When using the Scenario Tester to optimize a plant or find out how process changes could affect plant operation, you should ALWAYS gather as much operating plant data as possible and match those current plant operating conditions using ProMax. Matching plant data first is essential to the success of the plant analysis. The existing plant model allows you to verify the model and identify p ...

Reactor specifications vary depending on the Reactor Type, Reactor Configuration, and whether or not the Reactor is adiabatic. All Reactors require some specifications in the Reactor block dialog. The Reactor Type is a required specification. Choices are: Conversion, Equilibrium, Gibbs Minimization, Plug Flow, and Stirred Tank. To access available specifications in the Reactor block, firs ...

Depending on composition and pressure, multiple hydrate, water freeze out, or CO2 freeze out temperatures are possible. ProMax calculates up to three of these points. When only a single point is present, the solid is stable at all temperatures below that point. When three points are calculated, the solid is stable at temperatures between the Mid and High Temperature Hydrate/Freeze Points ...