University of Illinois at Urbana-Champaign researchers show a technology that charges batteries for electronic devices could provide fresh water from seawater. Electricity running through a salt water-filled battery draws the salt ions out of the water.
Smith said, “We are developing a device that will use the materials in batteries to take salt out of water with the smallest amount of energy that we can. One thing I’m excited about is that by publishing this paper, we’re introducing a new type of device to the battery community and to the desalination community.”
Interest in water desalination technology has risen as water needs have grown, particularly in drought-stricken areas. But technical hurdles and the enormous amounts of energy required have prevented wide-scale implementation. The most-used method, reverse osmosis, pushes water through a membrane that keeps out the salt, a costly and energy-intensive process. By contrast, the battery method uses electricity to draw charged salt ions out of the water.
The researchers were inspired by sodium ion batteries, which contain salt water. Batteries have two chambers, a positive electrode and a negative electrode, with a separator in between that the ions can flow across. When the battery discharges, the sodium and chloride ions – the two elements of salt – are drawn to one chamber, leaving desalinated water in the other.
In a normal battery, the ions diffuse back when the current flows the other direction. The Illinois researchers had to find a way to keep the salt out of the now-pure water.
“In a conventional battery, the separator allows salt to diffuse from the positive electrode into the negative electrode,” Smith said. “That limits how much salt depletion can occur. We put a membrane that blocks sodium between the two electrodes, so we could keep it out of the side that’s desalinated.”
The battery approach holds several advantages over reverse osmosis. The battery device can be small or large, adapting to different applications, while reverse osmosis plants must be very large to be efficient and cost effective, Smith said. The pressure required to pump the water through is much less, since it’s simply flowing the water over the electrodes instead of forcing it through a membrane. This translates to much smaller energy needs, close to the very minimum required by nature, which in turn translates to lower costs. In addition, the rate of water flowing through it can be adjusted more easily than other types of desalination technologies that require more complex plumbing.
Smith and Dmello conducted a modeling study to see how their device might perform with salt concentrations as high as seawater, and found that it could recover an estimated 80% of desalinated water. Their simulations don’t account for other contaminants in the water, however, so they are working toward running experiments with real seawater.
“We believe there’s a lot of promise,” Smith said. “There’s a lot of work that’s gone on in developing new materials for sodium ion batteries. We hope our work could spur researchers in that area to investigate new materials for desalination. We’re excited to see what kind of doors this might open.”
Its sounds like a great idea for producing fresh water. But it isn’t looking like the system will also be a rechargeable battery any more. The prospect to produce a lot more fresh water has great attraction in many parts of the world. Many of those place are not exactly supplied with low cost power to run desalination. This system may well offer a much lower cost to fresh water production and save a lot of energy where desalination is already underway.
Keep going guys, there is more market and need out there than you might think if the operating costs are low.
“Our findings have demonstrated that renewable pollens could produce carbon architectures for anode applications in energy storage devices,” said Vilas Pol, an associate professor in the School of Chemical Engineering and the School of Materials Engineering at Purdue University.
Batteries have two electrodes, called an anode and a cathode. The anodes in most of today’s lithium-ion batteries are made of graphite. Lithium ions are contained in a liquid called an electrolyte, and these ions are stored in the anode during recharging.
The researchers tested bee pollen- and cattail pollen-derived carbons as anodes. Bee pollen is a mixture of different pollen types collected by honey bees, the cattail pollens all have the same shape.
“Both are abundantly available,” said Pol, who worked with doctoral student Jialiang Tang. “The bottom line here is we want to learn something from nature that could be useful in creating better batteries with renewable feedstock.”
“I started looking into pollens when my mom told me she had developed pollen allergy symptoms about two years ago,” Tang said. “I was fascinated by the beauty and diversity of pollen microstructures. But the idea of using them as battery anodes did not really kick in until I started working on battery research and learned more about carbonization of biomass.”
The researchers processed the pollen under high temperatures in a chamber containing argon gas using a procedure called pyrolysis, yielding pure carbon in the original shape of the pollen particles. They were further processed, or “activated,” by heating at lower temperature – about 300º C – in the presence of oxygen, forming pores in the carbon structures to increase their energy-storage capacity.
The research showed the pollen anodes could be charged at various rates. While charging for 10 hours resulted in a full charge, charging them for only one hour resulted in more than half of a full charge, Pol said. “The theoretical capacity of graphite is 372 milliamp hours per gram, and we achieved 200 milliamp hours after one hour of charging,” he said.
The researchers tested the carbon at 25º C and 50º C to simulate a range of climates. “This is because the weather-based degradation of batteries is totally different in New Mexico compared to Indiana,” Pol said.
The findings ultimately showed the cattail pollens performed better than bee pollen.
The work is ongoing. Whereas the current work studied the pollen in only anodes, future research will include work to study them in a full-cell battery with a commercial cathode.
“We are just introducing the fascinating concept here,” Pol said. “Further work is needed to determine how practical it might be.”
Electron microscopy studies were performed at the Birck Nanotechnology Center in Purdue’s Discovery Park.
This is an amazing intuitive discovery. Its not likely that the cattail pollen can be synthesized easily. But the idea of farming cattails is an interesting idea. One wonders what the rest of the plant might have as a value.
The cost of a cattail pollen product remains unknown or even thought much about. Cattails grow in wet, gummy soils called “wetlands” that in the U.S are “protected” by the Environmental Protection Agency. They will have to be cultivated, or farmed, and as a wide expanse of farmers have found, making a wet spot gets EPA oversight costing tens of thousands of dollars in legal fees and likely returning the land back to its original state.
Its a great idea one expects will hit the bureaucratic wall before it gets very far. One suspects there will need to be an act of Congress before this kind of crop has a future. Maybe we could hide the cattails in a green house.
February 9, 2016 | Leave a Comment
Researchers at the University of Basel are studying a process combining solar driven water splitting with a fuel cell. A team of researchers led by the University of Basel chemists Catherine Housecroft and Edwin Constable are working together with the Swiss Federal Laboratories for Materials Science and Technology (Empa) to implement the new method.
An important factor in creating photo-electrochemical fuel cells is the precise arrangement of the individual components. “If you don’t do this, it’s like throwing all the different parts of a clock into a bag, giving it a shake and then hoping it will be possible to tell the time,” explains Prof. Edwin Constable from the University of Basel.
The process of splitting water (H2O) consists of two partial reactions, which are implemented with the help of different catalysts: water reduction (which produces the H2 and sets loose the O) and water oxidation (which produces the O2). The second is the more challenging of the two reactions, which is why research puts so much effort into the development of efficient and sustainable water oxidation catalysts. Simply stopping at O or ozone isn’t a really good idea.
To determine the perfect arrangement of the catalysts, the Basel-based chemists developed a water oxidation model in their current study which, although powered by electricity, generates the same chemical intermediate states as light. To accomplish this, they used compounds of the chemical element ruthenium as a catalyst. The critical feature is the self-assembly of the individual components in a hierarchical structure. The researchers thus succeeded in simulating fuel cells powered by light radiation. This model allowed them to test the position and efficiency of the individual components.
The ultimate portable and clean fuel is hydrogen, even with storage problems aside, the lure is intense for progress. Combining the solar water splitting and recombining in a fuel cell is interesting. A little storage could make a daylight hours separation operation to fuel cells electrical production run nearly continuously. The other hint is the system could be closed loop allowing no contaminates into the system. That might be an early adopter advantage.
The Swiss team notes they have stability and efficacy in a 10 hour operation before the test system stops. They haven’t set out to work up system stability, but 10 hours right out of the idea point is remarkable.
There are some issues that will stall the system awaiting developments in other material sciences. But these folks may be at a leading edge of what actually comes to market. It will be interesting to see how much energy from the sun gets into a grid.
Artificial photosynthesis for water splitting is one of the most promising approaches we have.
Researchers at Utrecht University, the Netherlands reveal in a new study a novel mechanism for controlling the energy transfer between electrons and the bismuth crystal lattice. Mastering this effect could, ultimately, help convert waste heat back into electricity.
At the atomic level, bismuth displays a number of quirky physical phenomena. Piotr Chudzinski from Utrecht University investigated the collective motion of electrons in bismuth, which behaves in a fluid manner with waves propagating in it, a phenomenon referred to as a low energy plasmon. Electrons moving throughout the material constantly aim to preserve the same density.
Bismuth exhibits two types of electrons – extremely light ones and heavier ones – moving at different speeds. As a result, an area of less dense electron liquid is formed. In response, electrons move back to compensate at the lower density end. Yet, some of them move faster than others. And a more sparsely dense area appears in another part of the material. And so on and so forth. . .
The study paper, published in the European Physical Journal B, available in open access, demonstrates that the low energy plasmons, when tuned to the same wavelength as the lattice vibrations of the bismuth crystal, or phonons, can very efficiently slow lattice motion. In essence, this plasmon-phonon coupling mechanism, once intensified under specific conditions, could be a new way of transferring energy between electrons and the underlying crystal lattice.
One important potential is that the plasmon-phonon coupling can help to explain a long since observed, significant effect in bismuth: the so called Nernst Effect. The Nernst Effect occurs when a sample is warmed on one side and subjected to a magnetic field, causing it to produce a significant electrical voltage in the perpendicular direction. Thus, it turns heat into useful electricity. Within the new interpretation the Nernst Effect scales up with temperature in a manner that is in line with experimental observations in bismuth, lends strong support to the theory.
The study is more important than a first impression might imply. The Nernst Effect is a particularly large effect that has until now defied mathematical support to the theory. Now that the math is in sight the engineering could soon follow.
With such an incredible amount of heat escaping the economy, an efficiently working and hopefully low cost recovery of heat directly to electricity would be a boon to energy efficiency and reducing expenses. Lets hope industry takes notice at this very early point.
Researchers at Kazan University collaborating with their peers from Stanford University are working on catalysts that provide combustion during the heavy oil recovery process. The catalysts developed by the group have already shown promising results in lab tests, and the work is continuing.
Kazan University’s Dr, Andrey Galukhin won a grant for this particular work from Russian Foundation for Basic Research in 2015. The collaborating group’s latest results have been published in Energy and Fuels.
Andrey Galukhin In His Lab. Image Credit: Kazan University. Click image for the largest view.
Projected heavy oil and viscous oil reserves in Russia are estimated to be 40-50 billion barrels and a significant portion of that volume lies within Tatarstan. Heavy oil extraction warrants special technological processes, and research in that direction is currently becoming the center of attention in the heavy oil-rich countries of the USA, Canada, Venezuela, and Russia.
Galukhin explained, “Calorimetric experiments show that crude oil with higher saturate content and low resin fraction has higher heating value. Additionally, the crude oils undergo two major transitions when subjected to an oxidizing and constant rate environment known as low- and high-temperature oxidations at each heating rate studied.
“There are ways to pump extremely hot steam into a reservoir to liquefy viscous oil, what facilitates the extraction. However, there are limitations – if the reservoir more than 1 km deep, steam loses most of its heat energy. That is why in-situ combustion is interesting for us – the heat for liquefying is generated in the reservoir. Our group works on catalysts that provide combustion during this process. The catalysts help to oxidize oil deposits in reservoirs that are relatively resistant to burning,” he said.
This is the first information out about catalysts placed into a reservoir to facilitate a combustion to generate heat. The press release hints pretty clearly that new catalysts are involved and the work is ongoing, without much of a description about the catalysts. This is no great surprise coming out of that part of the world. It is something of a surprise that the group partners include someone at Stanford.
This is very useful research applicable perhaps for a very large resource in many countries. But with the current political climate this might get bottled up. As well as Stanford, collaboration includes Department of Petroleum and Natural Gas Engineering at the Middle East Technical University in Ankara, Turkey. You might note as of this date that the Russian Federation is flying military planes over Turkey who in turn shoots them down.
Lets hope the political class overlooks these researchers and the progress continues.