Modeling Surface Reactions in Porous Media and Reactive Pellet Beds

Edmund Dickinson October 10, 2017

In a previous blog post, we discussed why surfaces are special in chemical reactors. In this blog post, we’ll see how surface area is maximized in reactor structures such as pellet beds, and how we can simply and accurately simulate fixed-bed reactors in spite of their local geometric complexity and the importance of microscopic diffusion.

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Edmund Dickinson September 5, 2017

Precision machining and quality of surface finish are major concerns for manufacturers of metal parts. The promise of a contactless method to machine surfaces with submillimeter precision and a clean surface, on metals of almost any hardness, might seem too good to be true. However, such a method, pulsed electrochemical machining (PECM), was the focus of a detailed investigation using numerical modeling presented at the COMSOL Conference 2016 Munich.

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Edmund Dickinson July 13, 2017

In biophysics, electrochemistry, and the design of catalytic reactors, researchers and engineers exploit the special chemical and physical properties of solid surfaces involving both gas-solid and liquid-solid interfaces. This blog post discusses the basics of the kinetics of surface reactions at simple surfaces and how they can be modeled with the COMSOL Multiphysics® software. In a subsequent blog post, we will look at how mass transport and reaction kinetics at surfaces are described for homogenized porous media.

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Edmund Dickinson March 14, 2017

In corrosion analysis, we often want to study corroding surfaces whose electrical connectivity is not as simple as a controlled current or voltage. Instead, an electrode surface might be short circuited to another electrode through a direct connection, such as the electrical connection between a monopile and transition piece. Here, we look at how to describe these electrodes and external short circuits using the appropriate boundary conditions in the COMSOL Multiphysics® software.

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Edmund Dickinson February 9, 2017

Electrochemical impedance spectroscopy is a versatile experimental technique that provides information about an electrochemical cell’s different physical and chemical phenomena. By modeling the physical processes involved, we can constructively interpret the experiment’s results and assess the magnitudes of the physical quantities controlling the cell. We can then turn this model into an app, making electrochemical modeling accessible to more researchers and engineers. Here, we will look at three different ways of analyzing EIS: experiment, model, and simulation app.

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Edmund Dickinson October 25, 2016

A short circuit in a battery is bad news: the chemical energy stored in the battery is lost as heat, rather than being used to power a device. Short circuits create intense heat, which can degrade battery materials or lead to fires or explosions due to thermal runaway. To avoid conditions that lead to short circuits in devices and ensure that short circuits do not cause unsafe operating conditions, we can study lithium-ion battery designs with the COMSOL Multiphysics® software.

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Edmund Dickinson January 19, 2016

When studying a system’s chemical kinetics, it’s common to use perfectly mixed batch reactor assumptions and design experiments that keep mixing conditions ideal. Such assumptions include perfectly mixed (ideal tank reactors) and perfectly unmixed (ideal plug flow reactors). In reality, however, it’s rare that all of the reactor’s parts behave the same way. Space-dependent modeling is thus essential in understanding and optimizing chemical reactors. Let’s explore the development of a detailed reactor model, starting with a simple perfectly mixed example.

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Edmund Dickinson April 22, 2015

You might think you’re a smooth driver — but your engine probably doesn’t. Everyday obstructions like traffic lights and changing speed limits mean that the power demands of a car drivetrain vary rapidly. Since we expect new technologies like hybrid or electric vehicles to match the performance of existing cars in responding instantly to the demands of our right foot, designers need to make sure that this is possible and safe. One part of this involves modeling batteries.

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Edmund Dickinson January 7, 2015

Architects cannot just be artists. A new building must not only be aesthetically pleasing but also structurally sound. In the design of modern buildings, great attention is paid to concepts such as environmental comfort and energy efficiency. With a range of physical problems to address in the transition from a building’s concept to a completed design, the 21st century architect may turn to multiphysics software.

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Edmund Dickinson August 14, 2014

Diabetes is an incurable global killer: the World Health Organization estimates 350 million diabetics worldwide, with an average annual fatality rate close to 1%. Fortunately, modern medical science enables diabetics to manage their glucose levels and intake, so many countries have seen greatly reduced danger of the disease. Many diabetics must track their glucose levels throughout the day, requiring an accurate method for measuring the concentration of glucose in blood. For modern sensor designs, the method of choice is electrochemistry.

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Edmund Dickinson April 17, 2014

What’s a penny made of? Though they appear to be solid copper coins, they actually don’t contain much copper at all these days. Instead, the U.S. Mint saves money by applying only a veneer of valuable metal onto a less expensive one. Have you ever thought about the manufacturing process by which this is achieved? Let’s find out.

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