Chemical Reaction Engineering Module

New App: Biosensor Design

A flow cell in a biosensor contains an array of micropillars, and the concave surfaces of the pillars are coated with an active material that selectively adsorbs biomolecules in the sample stream. This application allows the user to change the design of the sensor by altering input parameters such as pillar diameter, grid spacing, and inlet velocity to see how it affects the detection results.

The Biosensor Design app shows a concentration slice after a successful simulation. The Biosensor Design app shows a concentration slice after a successful simulation.

The Biosensor Design app shows a concentration slice after a successful simulation.

New Surface CHEMKIN® Functionality in Chemistry and Reaction Engineering Interfaces

New functionality enables you to import Surface CHEMKIN® files with surface species and surface reaction data, in addition to the previously available CHEMKIN® import functionality for homogeneous reactions. This applies for all types of CHEMKIN files: reaction kinetics, transport properties, and thermodynamics. The Surface CHEMKIN® standard is particularly useful for modeling reactions on catalytic surfaces and heterogeneous reactions when you have reaction data available in the Surface CHEMKIN® format.

The modeling of a CVD reactor including adsorption, desorption, and surface reactions is investigated, where the new import of Surface CHEMKIN® formats functionality is used. The reaction mechanism is then coupled to the transport mechanisms in a detailed reactor geometry. The modeling of a CVD reactor including adsorption, desorption, and surface reactions is investigated, where the new import of Surface CHEMKIN® formats functionality is used. The reaction mechanism is then coupled to the transport mechanisms in a detailed reactor geometry.

The modeling of a CVD reactor including adsorption, desorption, and surface reactions is investigated, where the new import of Surface CHEMKIN® formats functionality is used. The reaction mechanism is then coupled to the transport mechanisms in a detailed reactor geometry.

New Gas Mixture Viscosity Correlation

A mixture viscosity prediction method is now available for gas mixtures in the Reaction Engineering and Chemistry interfaces. Previously, only pure gas viscosity predictions were available.

Film Resistance Capability Added to the Reactive Pellet Bed feature

The Reactive Pellet Bed functionality now has two alternatives to couple the macro-scale concentration to micro-scale concentration at a pellet-bulk fluid surface:

  • Continuous concentration
  • Film resistance (mass flux)

The new Film resistance option relates the mass transfer to/from the pellet to a film coefficient, hD, a common model when studying bioreactors and catalytic beds. Here, resistance to mass transfer is assumed in a thin film near the pellet surface in addition to inside the porous pellet. The mass transfer coefficients are automatically calculated from the Sherwood number, the latter of which is defined from either of the three empirical expressions:

  • Frössling
  • Rosner
  • Garner and Keey

The Film resistance option can automatically compute the film coefficient from the Sherwood number. Optionally, user-defined transfer coefficients can be entered. The Film resistance option can automatically compute the film coefficient from the Sherwood number. Optionally, user-defined transfer coefficients can be entered.

The Film resistance option can automatically compute the film coefficient from the Sherwood number. Optionally, user-defined transfer coefficients can be entered.

Improved Usability of Chemical Reactions in Porous Media

The Reactions source term in the Transport of Diluted Species in Porous Media interfaces now provides the following options to account for the reacting volume base for saturated and unsaturated porous media:

  • Total volume
  • Pore volume
  • Liquid phase
  • Gas phase

Using literature data for kinetic expressions is thereby simpler and less error prone, since they can be tabulated for different volume bases.

You can now select the proper reaction relation as the basis for the reaction rate expression. In this case, reaction per total pore volume is selected. You can now select the proper reaction relation as the basis for the reaction rate expression. In this case, reaction per total pore volume is selected.

You can now select the proper reaction relation as the basis for the reaction rate expression. In this case, reaction per total pore volume is selected.

Hygroscopic Swelling

Hygroscopic swelling is an effect of internal material strain caused by changes in moisture content. The new Hygroscopic Swelling multiphysics coupling is used to couple moisture concentration between the Transport of Diluted Species or Transport of Diluted Species in Porous Media interfaces and the Solid Mechanics interface.

Dusty Gas Model

Knudsen diffusion is included as an additional transport mechanism in the Transport of Concentrated Species interface to enable Dusty Gas models. This mechanism is available for the Fick’s law and Mixture-averaged diffusion models. The Dusty Gas model is sometimes preferred to accurately predict mass transport accompanied by chemical reactions in porous media, for example in catalytic membranes and fuel cell applications.

In gases, this mechanism is important for the transport rate if the mean free path of transported molecules is in the same order of magnitude or larger than the length scale of the system. For example, in a long pore with a narrow diameter (2 to 50 nm), the molecules frequently collide with the pore wall and the diffusion needs to be adjusted accordingly.

Knudsen diffusion is now available as a Transport Mechanism. Knudsen diffusion is now available as a Transport Mechanism.

Knudsen diffusion is now available as a Transport Mechanism.

Mass-Based Concentration Variables

The Transport of Concentrated Species interface now provides mass-based concentration variables (kg/m3) in addition to mass fractions. This can be used in postprocessing, reports, and visualization, adding the flexibility to present data in different units depending on the preferences of the person interpreting the results.

Infinite Element Domains in Darcy's Law Interfaces

The Darcy's Law interfaces now supports infinite element domains and more advanced computations of boundary fluxes.

Updated Tutorial: Multiscale 3D Packed Bed Reactor

In the tutorial, A Multiscale 3D Packed Bed Reactor, the following enhancements have been added for industrial relevance:

  • A plate with holes has been installed at the inlet of the reactor to simulate a more realistic design.
  • More complicated second-order reversible reaction kinetics have been included.
  • A time-dependent study that also shows the start-up behavior of the reactor is simulated.

One of the more common reactors in the chemical industry is the packed bed reactor, used for heterogeneous catalytic processes. This model is set up to calculate the concentration distribution in the reactor gas that flows around the pellets, but it also uses an extra dimension that models the concentration distribution inside each porous catalytic pellet. One of the more common reactors in the chemical industry is the packed bed reactor, used for heterogeneous catalytic processes. This model is set up to calculate the concentration distribution in the reactor gas that flows around the pellets, but it also uses an extra dimension that models the concentration distribution inside each porous catalytic pellet.

One of the more common reactors in the chemical industry is the packed bed reactor, used for heterogeneous catalytic processes. This model is set up to calculate the concentration distribution in the reactor gas that flows around the pellets, but it also uses an extra dimension that models the concentration distribution inside each porous catalytic pellet.

Updated Tutorial: GaAs Chemical Vapor Deposition (CVD)

The GaAs CVD application has been completely revised and now shows a much easier way to organize the complex system of bulk and surface reactions that are involved in a CVD process. It utilizes the new Reversible Reaction Group feature for CHEMKIN® import with a Surface CHEMKIN® file.

In semiconductor manufacturing, CVD reactors are used for depositing thin films on a substrate through molecules and molecular fragments adsorbing and reacting on a surface.

Chemical vapor deposition (CVD) allows a thin film to be grown on a substrate through molecules and molecular fragments adsorbing and reacting on a surface. The CVD system is modeled using momentum, energy, and mass balances including a detailed description of the gas phase and adsorption kinetics. The streamlines show the direction of the velocity vector, while the color plot shows the concentration profile of one of the reactants. Chemical vapor deposition (CVD) allows a thin film to be grown on a substrate through molecules and molecular fragments adsorbing and reacting on a surface. The CVD system is modeled using momentum, energy, and mass balances including a detailed description of the gas phase and adsorption kinetics. The streamlines show the direction of the velocity vector, while the color plot shows the concentration profile of one of the reactants.

Chemical vapor deposition (CVD) allows a thin film to be grown on a substrate through molecules and molecular fragments adsorbing and reacting on a surface. The CVD system is modeled using momentum, energy, and mass balances including a detailed description of the gas phase and adsorption kinetics. The streamlines show the direction of the velocity vector, while the color plot shows the concentration profile of one of the reactants.

New Tutorial: Protein Adsorption in an Ion-Exchange Column

Ion-exchange is a powerful method for separating proteins from solutions and is readily used in the biotech and pharmaceutical industries today. This new tutorial simulates an ion-exchange column for adsorption of two proteins.

The fluid phase contains four components: two proteins, solvent, and one salt. The adsorption/desorption kinetics are described by two equilibrium reactions where proteins displace ions adsorbed at the surface and vice versa. This tutorial highlights how reactions at chemical equilibrium can be studied in an ideal perfectly mixed reactor system in the Reaction Engineering interface. In addition, it shows how the kinetics from the ideal reactor set-up are exported to a 3D model, where the spatial effects on the reacting surface in the column are studied in detail.

Shown in the corresponding image is the surface concentration of one of the adsorbed proteins after 2 seconds of operation, on the porous structure of an ion-exchange resin in an ion-exchange column. The color plot shows the concentration (dark red is 7 moles/m3 and dark blue is 0). Shown in the corresponding image is the surface concentration of one of the adsorbed proteins after 2 seconds of operation, on the porous structure of an ion-exchange resin in an ion-exchange column. The color plot shows the concentration (dark red is 7 moles/m3 and dark blue is 0).

Shown in the corresponding image is the surface concentration of one of the adsorbed proteins after 2 seconds of operation, on the porous structure of an ion-exchange resin in an ion-exchange column. The color plot shows the concentration (dark red is 7 moles/m3 and dark blue is 0).

New Tutorial: Multicomponent Tubular Reactor

This tutorial demonstrates how the Chemistry and Transport of Diluted Species interfaces can be used to model and investigate complex reaction kinetics and multicomponent mass transfer. It studies an exothermic, irreversible reaction in a tubular reactor (liquid phase, laminar flow regime). To keep its temperature down, the reactor uses a cooling jacket with a constant coolant temperature.

Distribution of a reactant and product in a jacket-cooled multicomponent tubular reactor. Distribution of a reactant and product in a jacket-cooled multicomponent tubular reactor.

Distribution of a reactant and product in a jacket-cooled multicomponent tubular reactor.