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Dr. Colleen Spiegel

Dr. Colleen Spiegel

Dr. Colleen Spiegel is a mathematical modeling and technical writing consultant (President of SEMSCIO) and Professor holding a Ph.D. and an MSc degree in Engineering. She has seventeen years of experience in engineering, statistics, data science, research & technical writing work for many companies as a consultant, employee, and independent business owner. She is the author of ‘Designing and Building Fuel Cells’ (McGraw-Hill, 2007) and ‘PEM Fuel Cell Modeling and Simulation Using MATLAB’ (Elsevier Science, 2008). She previously owned Clean Fuel Cell Energy, LLC, which was a fuel cell organization that served scientists, engineers, and professors world-wide.

How Ion Exchange Works
In nature, the majority of gases, liquids, and solids are not charged (in the neutral form). Ion exchange, where free ions are exchanged for different ions, occurs when there is an open network structure to carry the ions through it. There are many natural and man-made mediums that are ion exchangers, including solids, liquids, and gases. The medium needs to be in contact with the ion exchanger and these two entities exchange some of its ions for similarly charged ions. The medium is often a solid ion exchanger in contact with an aqueous solution or gas. If you recall from chemistry, there ..
An Introduction to Cation Exchange Membranes
Cation exchange membranes (CEMs) are frequently referred to as proton exchange membranes (PEMs) because they are often used in chemical reactions that generate protons. CEMs are used in various applications ranging from proton exchange membrane and microbial fuel cells to chlorine and caustic soda production. The cation exchange membrane (CEM) contains negatively charged functional groups (PO3-, COO–, and C6H4O–) in the membrane backbone, which allows cations to pass through. There are many types of CEM that have been used in the literature, including Nafion©, Fumatech, Aquiv..
Membrane Properties and Characterization for Zero-Gap CO2 Electrolyzers
Zero-gap electrolyzers are similar to fuel cells in design because the heart of the electrolyzer consists of two electrodes pressed against a membrane. These electrolyzers are called “zero-gap” because there is no gap between the cathodes, anodes, and the electrolyte. This design decreases the distance for ion transport because the layers are pressed or bonded together. The zero-gap CO2 electrolyzers can achieve high current densities (≥100 mA/cm2) by delivering gaseous CO2 to the cathode. The efficiency of these electrolyzers depends upon the catalysts used, the operating conditions, and o..
Carbon Dioxide Capture and Conversion
An Introduction to CO2 Capture and Conversion Electrochemical devices that convert CO2 into fuels and valuable compounds have been undergoing extensive research for over a decade now. The research in this area has been driven by the desire to reduce reliance on fossil fuels and reduce greenhouse emissions. As you are probably aware, the majority of the world’s energy used for transportation, industrial, and residential uses are made from coal, petroleum, and natural gas. An Increase in CO2 Emissions As we are all aware, the consumption of fossil fuels has led to an increase in C..
Compact Transient Model for Nafion Membranes

A numerical model was developed to predict the water concentration, temperature, potential and pressure across a Nafion membrane used in proton exchange membrane (PEM) based fuel cells. The numerical model consists of simultaneously calculating the diffusive flux for water and hydrogen, the proton potential and the pressure and temperature at each node...

An Introduction to Ion Exchange Membranes and Salt Splitting

Ion-exchanges membranes (IEMs) have many applications beyond fuel cells -- they can also be used to synthesize all types of compounds that are used in various industries. The most popular IEMs consist of polymeric resins with charged functional groups based upon their ion selectivity, they are referred to as anion-exchange (AEM) and...

Anion Exchange Membranes (AEMs)

Anion exchange membranes (AEMS) have been an active area of research for over a decade. AEMS can be used for fuel cells, redox flow batteries, electrolyzers, and even water desalination membranes. The electrolyte layer is the “heart” of electrochemical cells such as fuel cells, batteries, and because it transports ions from...

An Introduction to Alkaline Fuel Cells

Alkaline fuel cells (AFCs) was one of the first extensively researched fuel cell types and was used by NASA for the Gemini, Apollo, and Space Shuttle missions. The first alkali electrolyte fuel cell was built by Francis Thomas Bacon (1904–1992) in 1939. He used potassium hydroxide for the electrolyte and...

The Use of Hydrogen as an Energy Storage System

Many countries around the world have been diligently working towards implementing renewable energy plants for over a decade. According to the International Energy Agency (IEA), renewables in the form of hydropower, bioenergy, wind and solar will account for 18% of primary energy by 2035. Since 2013, more electrical grid capacity was added...

Standards and Requirements for Solar Systems

If you are considering the installation of a solar system (by yourself or by a solar company), there are several codes and regulations that need to be adhered to. These include the National Electrical Code (NEC), local permits, building codes, fire codes, and grounding systems. In addition, every component in a...

Why Fuel Cells Lead The Road to Long-Term Sustainability for Vehicles

Fuel cells have now been under development for several decades. Since I first became interested in fuel cells in the 1990’s, I have seen waves of excitement and investment followed by periods of skepticism and disillusionment. Only a few companies have stayed in the game, with Ballard in Canada and the large automakers such as Toyota being a critical and essential part for...

A One-Dimensional Heat, Mass and Charge Transfer Model for a Polymer Electrolyte Fuel Cell Stack

A one-dimensional heat, mass and charge transfer model was developed for a polymer electrolyte fuel cell stack to predict the temperatures, mass flows, pressure drops, and charge transport of each fuel cell layer over different operating conditions. The fuel cell layers’ boundaries were...

A Review of Mathematical Modeling of Proton Exchange Membrane and Direct Methanol Fuel Cells

There has been a lot of emphasis on the development of long-lasting, efficient and portable, power sources for further technology improvement in commercial electronics devices, medical diagnostic equipment, mobile communication and military applications. These systems all require...

What’s So Good About Hydrogen?

Many automotive manufacturers have chosen fuel cell technology as the long-term solution to replace combustion engines when the oil stops flowing -- but that’s not expected to happen for at least another 15 years (even if we keep using it at our current rate). So why are we...

Building a Micro DMFC Design

This blog post includes a quick fuel cell introduction, parts list and design for a 1 cm x 1 cm (active area) fuel cell. This summary was put together mainly for students interested in fuel cell research. Figure 1 presents a summary of the dimensions and basic characteristics of most MEMs fuel cell stacks in the...