Ulsan National Institute of Science and Technology (UNIST) researchers have come up with a new anode for natural gas fuel cells. The development may make commercialization of the natural gas fuel cell practical thanks to the development of electrode materials that maintain long-term stability in hydrocarbon fuels. The advantage of using this material includes that it uses internal transition metal as a further catalyst in a fuel cell’s operating condition.

The SEM images present surface morphologies of Pr0.5Ba0.5Mn0.85Ni0.15O3 before reduction and PrBaMn1.7Ni0.3O5+δ after reduction in humidified (3% H2O) H2 at 800 °C for 4 h; scale bar 500 nm. In the SEM image of PrBaMn1.7Ni0.3O5+δ, the purple circles indicate the exsolved nanoparticles. Image Credit: Ulsan National Institute of Science and Technology. Click image for the largest view.

The breakthrough comes from a research, conducted by Professor Guntae Kim of the Energy and Chemical Engineering department at UNIST in collaboration with Professor Jeeyoung Shin of Sookmyoung Women’s University, Professor Jeong Woo Han of University of Seoul, Professor Young-Wan Ju of Wonkwang University, and Professor Hu Young Jeong of UNIST.

Their results have been published the journal Nature Communications. The development has emerged as the promising candidate for the next generation direct hydrocarbon solid oxide fuel cells (SOFCs) technology.

A solid oxide fuel cells (SOFCs) are an electrochemical conversion device that produces electricity by oxidizing a fuel. SOFCs are still subject to a fairly intense development for their unforgettable competitive benefits of long-term stability, a high fuel flexibility, low emissions, as well as relatively low cost.

SOFCs are possible next generation fuel cells, as they are capable of raising efficiency higher than 90% when using the exhaust heat. However, successful commercialization of SOFCs has been delayed due to its high production cost mainly related with the development of electrode materials in hydrocarbon fuel cells.

Professor Kim has solved the problem of securing the hydrogen by developing a new anode material (catalyst) which can directly use hydrocarbons, known as natural gas liquids (LGLs) and LPG, as a fuel of SOFCs. Using this newly-developed catalyst, SOFCs can operate the fuel cell without converting the hydrocarbon into hydrogen externally.

In the study, the research team proposed that transition metals are exsolved from the new anode material in reducing atmosphere. Generally, the transition metals act as fuel oxidation catalyst in SOFCs. They also reported that the exsolved Co and Ni nanoparticles on the surface of the layered perovskite show good stability with no remarkable degradation. Moreover the single cell presents 1.2 W/cm2 in H2 at 800o C, indicating that the performance is twice as high as that of the conventional electrode material (0.6 W/cm2).

Professor Kim the corresponding author of the paper said, “Although the existing anode materials demonstrated good initial performance, due to their long-term instability and complex manufacturing process, they could not be reliably operated when using hydrocarbon directly as fuel. The new anode material reduces manufacturing process and maintains good stability, which is expected to accelerate the commercialization of SOFCs.”

According to the research team, their findings provide a key to understand the exsolution trends in transition metals (Mn, Co, Ni and Fe) containing perovskites and design highly catalytic perovskite oxides for fuel reforming and electro-oxidation.

Lets hope this one does it. Going direct from natural gas to electricity at 90% is way way better than blowing combustion exhaust through a turbine or boiling water to make dry steam.

Carnegie Mellon University (CMU) researchers believe we are “running towards a cliff with no fence” from the current plans to retire U.S. power plants. The team found that power plant retirement trends will complicate achieving long-term carbon dioxide emission reduction targets and require a significant increase in capital investments.

In their paper now published in Energy Policy, CMU’s David Rode and Paul Fischbeck and alumnus Antonio Páez, who now works for DAI Management Consultants, examined more than a century of power plant construction and retirement data.

In additional, a shift in investment emphasis from adding megawatts of generating capacity at low cost to reducing tons of CO2 emissions is creating an imbalance that may pressure grid reliability over the next two decades.

Rode, a doctoral candidate in the Department of Social and Decision Sciences said, “There has been comparatively little research into how long power plants actually live. Most of the industry is focused on the addition of new generating capacity, but the retirement of aging capacity is equally important.”

While retiring older power plants is often thought of as a way to reduce emissions, as less efficient plants are taken out of service, the U.S. also stands to lose a substantial amount of zero-emitting power plants when the vast majority of the existing nuclear power plant fleet retires between 2030 and 2040, if not before.

Fischbeck, professor of social and decision sciences and engineering and public policy and a world renowned risk expert said, “Some 90 percent of every megawatt ever built is still in operation and now is more than 28 years old on average. One of the interesting results from our study was that younger coal plants have tended to retire earlier than older coal plants. As these younger plants generally have lower emissions, their retirement tends to be less environmentally beneficial than initially thought.”

With the failure of the EPA’s proposed Clean Power Plan and the withdrawal from the Paris Climate Agreement, the U.S. is now without a national CO2 reduction objective. The removal of those regulatory constraints expands the opportunities available to utilities and improves their investment flexibility, but it also increases regulatory uncertainty. However, many regions, states and even cities continue to have mandates to reduce CO2 emissions. Coupled with the uncertainty surrounding future national CO2 regulation, these varying mandates create economic conditions that inhibit investment and thereby place even more emphasis on the continuing performance of existing power plants.

“A key factor in meeting these objectives – or any future national ones – will be the retirement of existing zero-emitting facilities,” said Rode.

The study also provided insight into capital investment behavior in the power generation sector.

“Despite perennial claims of underinvestment, dollars invested have grown steadily – in constant dollars – for decades. The difference is that they have tended to lead to fewer megawatts of new capacity and have focused instead on reductions in emissions,” Rode said.

Rode, Fischbeck and Páez looked at power sector capital investments and found that dollars spent per megawatt-hour generated has increased by nearly 300 percent over the past two decades. However, electric generation has increased by only 26 percent. The incremental expense growth has instead been channeled, in part, to improving environmental performance (tons of CO2 emitted per megawatt-hour) by 17 percent.

Páez said, “Evaluating whether this large increase in investment was well spent requires rethinking how investment performance is measured.”

Given the country’s rapidly aging power plants, retirements are likely to increase substantially after 2030.

“The spending required just to replace the retiring plants and meet a modest level of growth will require up to five times the level of historical investment activity,” Fischbeck said.

Rode continued, “Our research shows that the amount of generation added in 2002, the previous record year, will be needed each year between 2030 and 2040 at a cost of more than $110 billion per year – a level roughly three times that of the average of the last twenty years. There is no question that the implications of this retirement cliff after 2030 are significant from cost, reliability, and environmental perspectives. Careful planning must begin now.”

We won’t be able to say we weren’t warned. The U.S. has a lot of regulated utilities subject to intense political pressure to do, well, trendy stuff. The costs of the benefits of close regulation invaded by special interests is soon be known in fact, not from a study. For those not watching another study came out last week that shoulda woulda coulda killed the climate change silliness again. Its a scam that will not die.

CO2 is a huge valuable resource that we’re wasting away into the atmosphere. But first the lights have to go on, the homes and offices stay cool or warm and factories make the things we need. Electricity isn’t just critical, its crucial. Just try to get along 60 seconds without it.

University of Washington (UW) researchers have developed a fast, inexpensive method to make electrodes for supercapacitors. The important applications include electric cars, wireless telecommunications and high-powered lasers.

But to realize these applications, supercapacitors need better electrodes, which connect the supercapacitor to the devices that depend on their energy. These electrodes need to be both quicker and cheaper to make on a large scale and also able to charge and discharge their electrical load faster.

This is a full x-ray reconstruction of a coin cell supercapacitor in a a sodium ion battery case. Image Credit: William Kuykendall, University of Washington. Click image for the largest view.

A team of engineers at the University of Washington thinks they’ve come up with a process for manufacturing supercapacitor electrode materials that will meet these stringent industrial and usage demands

The researchers, led by UW assistant professor of materials science and engineering Peter Pauzauskie, published their paper in the journal Nature Microsystems and Nanoengineering describing their supercapacitor electrode and the fast, inexpensive way they made it.

Their novel method starts with carbon-rich materials that have been dried into a low density matrix called an aerogel. This aerogel on its own can act as a crude electrode, but Pauzauskie’s team more than doubled its capacitance, which is its ability to store electric charge.

These inexpensive starting materials, coupled with a streamlined synthesis process, minimize two common barriers to industrial application: cost and speed.

Pauzauskie saud, “In industrial applications, time is money. We can make the starting materials for these electrodes in hours, rather than weeks. And that can significantly drive down the synthesis cost for making high-performance supercapacitor electrodes.”

Effective supercapacitor electrodes are synthesized from carbon-rich materials that also have a high surface area. The latter requirement is critical because of the unique way supercapacitors store electric charge. While a conventional battery stores electric charges via the chemical reactions occurring within it, a supercapacitor instead stores and separates positive and negative charges directly on its surface.

Co-lead author Matthew Lim, a UW doctoral student in the Department of Materials Science & Engineering explained, “Supercapacitors can act much faster than batteries because they are not limited by the speed of the reaction or byproducts that can form. Supercapacitors can charge and discharge very quickly, which is why they’re great at delivering these ‘pulses’ of power.”

Fellow lead author Matthew Crane, a doctoral student in the UW Department of Chemical Engineering takes the explanation further with, “They have great applications in settings where a battery on its own is too slow. In moments where a battery is too slow to meet energy demands, a supercapacitor with a high surface area electrode could ‘kick’ in quickly and make up for the energy deficit.”

To get the high surface area for an efficient electrode, the team used aerogels. These are wet, gel-like substances that have gone through a special treatment of drying and heating to replace their liquid components with air or another gas. These methods preserve the gel’s 3-D structure, giving it a high surface area and extremely low density. It’s like removing all the water out of Jell-O with no shrinking.

Pauzauskie noted, “One gram of aerogel contains about as much surface area as one football field.”

Crane made aerogels from a gel-like polymer, a material with repeating structural units, created from formaldehyde and other carbon-based molecules. This ensured that their device, like today’s supercapacitor electrodes, would consist of carbon-rich materials.

Previously, Lim demonstrated that adding graphene, which is a sheet of carbon just one atom thick to the gel, imbued the resulting aerogel with supercapacitor properties. But, Lim and Crane needed to improve the aerogel’s performance, and make the synthesis process cheaper and easier.

In Lim’s previous experiments, adding graphene hadn’t improved the aerogel’s capacitance. So they instead loaded aerogels with thin sheets of either molybdenum disulfide or tungsten disulfide. Both chemicals are used widely today in industrial lubricants.

The researchers treated both materials with high-frequency sound waves to break them up into thin sheets and incorporated them into the carbon-rich gel matrix. They could synthesize a fully-loaded wet gel in less than two hours, while other methods would take many days.

After obtaining the dried, low-density aerogel, they combined it with adhesives and another carbon-rich material to create an industrial “dough,” which Lim could simply roll out to sheets just a few thousandths of an inch thick. They cut half-inch discs from the dough and assembled them into simple coin cell battery casings to test the material’s effectiveness as a supercapacitor electrode.

Not only were their electrodes fast, simple and easy to synthesize, but they also sported a capacitance at least 127% greater than the carbon-rich aerogel alone.

Lim and Crane expect that aerogels loaded with even thinner sheets of molybdenum disulfide or tungsten disulfide – theirs were about 10 to 100 atoms thick – would show an even better performance. But first, they wanted to show that loaded aerogels would be faster and cheaper to synthesize, a necessary step for industrial production. The fine-tuning comes next.

The team believes that these efforts can help advance science even outside the realm of supercapacitor electrodes. Their aerogel-suspended molybdenum disulfide might remain sufficiently stable to catalyze hydrogen production. And their method to trap materials quickly in aerogels could be applied to high capacitance batteries or catalysis.

This looks like a fine example of innovative thinking with a top level result. The technology looks to be ready for some commercial experimentation to see how a real world application might work out.

On the other hand the optimism looks pretty far out. Catalyst operations are usually in very trying environments and need pretty tough materials to be successful. But with these folks level of innovations, lets watch with anticipation, they just might get it workable.

Imperial College London engineers have overturned a 100-year-old scientific law used to describe how fluid flows through rocks.

Scientists from the College have used the Diamond Light Source facility in the UK to make 3D videos that show in more detail than ever before how fluids move through rock.

For over one hundred years, engineers have been modeling how multiple fluids flow through rocks for a range of reasons. For example, modeling fluid flow enables engineers to determine how to extract oil and gas. Understanding how seawater flows through rocks provides insights into the volatility of Earth’s crust, and predicting how fresh water flows through rocks enables engineers to manage water resources. More recently, engineers have been modeling how CO2 flows through rock as part of Carbon Capture and Storage.

Previously, scientists have used a formula for modeling how fluids move through rocks. It’s called Darcy’s Extended Law and the premise of it is that gases move through rock via their own separate, stable, complex, microscopic pathways. This has been the underpinning approach used by engineers to model fluid flow for the last 100 years.

However, the Imperial scientists have discovered that rather than flowing in a relatively stable pattern through rocks, the flows are in fact very unstable. The pathways that fluids flow through actually only last for a short period of time, tens of seconds at most, before re-arranging and forming into different ones. The team have called this process dynamic connectivity.

The importance of the discovery of dynamic connectivity is that engineers around the world will now be able to more accurately model how fluids flow through rock.

Dr. Catriona Reynolds, lead author on the study published in the journal Proceedings of the National Academy of Sciences and who completed her PhD in the Department of Earth Science and Engineering at Imperial, said: “Trying to model how fluids flow through rock at large scales has proven to be a major scientific and engineering challenge. Our ability to predict how these fluids flow in the subsurface is not much better than it was 50 years ago despite major advances in computer modeling technology. Engineers have long suspected that there were some major gaps in our understanding of the underlying physics of fluid flow. Our new observations in this study will force engineers to re-evaluate their modeling techniques, increasing their accuracy.”

To create the 3D images the researchers in today’s study used the synchrotron particle accelerator at the Diamond Light Source. The synchrotron enables the researchers to take 3D image at speeds much faster than a conventional laboratory X-ray instrument – around 45 seconds compared to hours for a laboratory based instrument. This enabled them to see the dynamics, which had not been previously observed before.

But an even higher time resolution would significantly enhance the observations. These fluid pathways re-arrange themselves quickly, so ideally the team would like the observations to capture every 100th of a second. This time resolution is only possible right now using optical light from microscopes combined with high-speed cameras. However, they are limited in their ability to observe fluids moving through real rocks.

The next steps will see the team attempting to overcome this technological obstacle using a combination of novel optical and X-ray imaging techniques. This could enable them to model fluid flow on a large scale, which would be of use for modeling CO2 storage, the production of oil and gas, and the migration of fluids deep in Earth’s crust.

This research is certain to have an impact on secondary and tertiary oil recovery and have an effect of hydraulic fracturing technology. There will be adjustments made to the known oil reserves over the coming years and likely some improvements in recovery techniques and research. This is bigger news that one might have from a first impression. Its very very good news indeed.

Okinawa Institute of Science and Technology (OIST) Coordination Chemistry and Catalysis Unit led by Prof. Julia Khusnutdinova have developed an efficient CO2 recycling catalyst based on an inexpensive and abundant metal: manganese. Manganese is the third most abundant metal in Earth’s crust after titanium and iron, and presents much lower toxicity as compared to many other metals used in CO2 hydrogenation.

The scientists initially looked for inspiration within the natural world: hydrogenation is a reaction that occurs in many organisms that would not have access to precious metals or phosphines. They observed the structure of specific enzymes – hydrogenases – to understand how they could accomplish hydrogenation using simple, Earth-abundant materials. To facilitate the hydrogenation, enzymes utilize a ‘smart’ arrangement where the surrounding organic framework cooperates with a metal atom – like iron – efficiently kick-starting the reaction.

Crystal structure of the manganese-based catalyst reported in the study. The manganese atom (in purple) is at the center of the frame – the ligand – which facilitates the hydrogenation of CO2. Image Credit: Okinawa Institute of Science and Technology. Click image for the largest view.

The team’s research paper has been published in The American Chemical Society’s Catalysis.

Dr. Abhishek Dubey, the first author of the study said, “After looking at hydrogenases, we wanted to check if we could make artificial molecules that mimics these enzymes using the same type of common materials, like iron and manganese.”

The main challenge of this study was to build an adequate frame – called a ligand – around the manganese to induce the hydrogenation. The scientists came up with a surprisingly simple ligand structure resembling natural hydrogenase enzymes with a twist from typical phosphine catalysts.

In a novel twist, Dr. Dubey said, “In most cases, ligands support the metal without directly taking part in a chemical bond activation. In our case, we believe the ligand directly participates in the reaction.”

In ligand design, the structure of a ligand is tightly linked to its efficiency. The new catalyst – the ligand and the manganese together – can perform more than 6,000 turnovers in a hydrogenation reaction, converting more than 6,000 times CO2 molecules before decaying. And this new ligand, the outcome of a collaboration with an international team including Prof. Carlo Nervi and Mr. Luca Nencini from University of Turin in Italy and Dr. Robert Fayzullin from Russia, is simple to manufacture and stable in the air.

For now, the catalyst is able to transform carbon dioxide into formic acid, a widely-used food preservative and tanning agent, and formamide, which has industrial applications. But the versatility of this catalyst opens many other possibilities.

“Our next goal is to utilize such structurally simple, inexpensive manganese catalysts to target other types of reactions in which CO2 and hydrogen can be converted into useful organic chemicals,” concluded Prof. Khusnutdinova.

The press release offered a good deal of background information.

CO2 is cheap, readily available and non-toxic carbon source. During the past few years there have been efforts to turn carbon dioxide into valuable wares, or ‘value-added’ products.

For instance, carbon dioxide enables energy storage by reacting with hydrogen gas – called the hydrogenation process – transforming the mixture into higher energy liquid compounds such as methanol that can be easily transported and used as fuel for cars. Similarly, carbon dioxide hydrognation in the presence of other chemicals can lead to the formation of various value-added products widely used in industry such as formic acid, formamides, or formaldehyde. These chemicals can also potentially be used for energy storage as, for example, heating formic acid under certain conditions allow for the release of hydrogen gas in a controlled and reversible fashion.

Conversion of carbon dioxide into useful products is complicated by the fact that CO2 is the most oxidized form of carbon and as such a very stable and unreactive molecule. Therefore, the direct reaction of CO2 with hydrogen requires high energy, making the process economically unfavorable.

This problem can be overcome using catalysts, which are compounds used in small amounts to accelerate chemicals reactions. For CO2 hydrogenation purposes, most known catalysts are based on precious metals such as iridium, rhodium or ruthenium. While excellent catalysts, the scarcity of these precious metals makes it difficult to use them at industrial scales. They are also hard to recycle and potentially toxic for the environment.

Other catalysts use cheaper metals such as iron or cobalt but require a phosphorus-based molecule – called phosphine -surrounding the metal. Phosphines are not always stable around oxygen and sometimes burn violently in an air atmosphere, which presents another problem for the practical applications.

Recycling CO2 is looking more practical with each new development. One of these days an idea is going to come out that is a cost effective way to re-harness the oxidized carbon back into useful products. It might not be long now.


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