Researchers Greg O’Neil of Western Washington University and Chris Reddy of Woods Hole Oceanographic Institution have found an unusual and untapped class of chemical compounds in an algae species to synthesize two different fuel products, in parallel, a from the single algae. The algae is a common algae commercially grown to make fish food that holds promise as a source for both biodiesel and jet fuel.
O’Neil, the study’s lead author said, “It’s novel, it’s far from a cost-competitive product at this stage, but it’s an interesting new strategy for making renewable fuel from algae.”
Algae contain fatty acids that can be converted into fatty acid methyl esters, or FAMEs, the molecules in biodiesel.
For their study, O’Neil, Reddy, and colleagues targeted a specific algal species called Isochrysis for two reasons: First, because growers have already demonstrated they can produce it in large batches to make fish food. Second, because it is among only a handful of algal species around the globe that produce fats called alkenones. These compounds are composed of long chains with 37 to 39 carbon atoms, which the researchers believed held potential as a fuel source.
Biofuel prospectors may have dismissed Isochrysis because its oil is a dark, sludgy solid at room temperature, rather than a clear liquid that looks like cooking oil. The sludge is a result of the alkenones in Isochrysis, which is precisely what makes it a unique source of two distinct fuels.
Alkenones are well known to oceanographers because they have a unique ability to change their structure in response to water temperature, providing oceanographers with a biomarker to extrapolate past sea surface temperatures. But biofuel prospectors were largely unaware of alkenones. “They didn’t know that Isochrysis makes these unusual compounds because they’re not oceanographers,” said Reddy, a marine chemist at WHOI.
Reddy and O’Neil began their collaboration first by making biodiesel from the FAMEs in Isochrysis. Then they had to devise a method to separate the FAMEs and alkenones in order to achieve a free-flowing fuel. The method added steps to the overall biodiesel process, but it supplied a superior quality biodiesel, as well as “an alkenone-rich . . . fraction as a potential secondary product stream,” the authors wrote.
“The alkenones themselves, with long chains of 37 to 39 carbons, are much too big to be used for jet fuel,” says O’Neil. But the researchers used a chemical reaction called olefin metathesis (which earned its developers the Nobel Prize in 2005). The process cleaved carbon-carbon double bonds in the alkenones, breaking the long chains into pieces with only 8 to 13 carbons. “Those are small enough to use for jet fuel,” O’Neil says.
The scientists believe that by producing two fuels – biodiesel and jet fuel – from a single algae, their findings hold some promise for future commercialization. They stress that this is a first step with many steps to come, but they are encouraged by the initial result.
“It’s scientifically fascinating and really cool,” Reddy says. “This algae has got much greater potential, but we are in the nascent stages.”
Among their next steps is to try to produce larger quantities of the fuels from Isochrysis, but they are also exploring additional co-products from the algae. The team believes there are a lot of other potential products that could be made from alkenones.
“Petroleum products are everywhere – we need a lot of different raw materials if we hope to replace them,” says O’Neil. “Alkenones have a lot of potential for different purposes, so it’s exciting.”
As well as the two fuels from one species there is another outstanding point in the story. These gentlemen are very much the heads up wide view folks that will find the paths to energy and fuel supplies that are sustainable, low cost and less threatening to the hysteria inclined.
January 28, 2015 | Leave a Comment
University of Michigan (UM) researchers have designed a Kevlar barrier that goes between the anode and cathode electrodes of lithium ion batteries. The new battery technology should be able to prevent the kind of fires that grounded Boeing’s 787 Dreamliners in 2013.
The barrier is made with nanofibers extracted from Kevlar, the tough material in bulletproof vests. The barrier stifles the growth of metal tendrils that can become unwanted pathways for electrical current by removing the conductive path between the electrodes that shorts causing intense sudden heating and the fires.The UM team of researchers also founded Ann Arbor-based Elegus Technologies to bring this research from the lab to market. Thirty companies have requested samples of the material. Mass production is expected to begin in the fourth quarter 2016.
Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering said, “Unlike other ultra strong materials such as carbon nanotubes, Kevlar is an insulator. This property is perfect for separators that need to prevent shorting between two electrodes.”
Lithium-ion batteries work by lithium ions moving from one electrode to the other. This creates a charge imbalance, and since electrons can’t go through the membrane between the electrodes, they go through a circuit instead and do something useful along the way.
The lithium atoms can build themselves into fern-like structures, called dendrites, which eventually poke through the membrane if the holes in the membrane are too big. When they reach the other electrode, the electrons have a path within the battery, shorting out the circuit. This is how the battery fires on the Boeing 787 are thought to have started.
Siu On Tung, a graduate student in Kotov’s lab, as well as chief technology officer at Elegus explained, “The fern shape is particularly difficult to stop because of its nanoscale tip. It was very important that the fibers formed smaller pores than the tip size.”
While the widths of pores in other membranes in use are a few hundred nanometers, or a few hundred-thousandths of a centimeter, the pores in the membrane developed at UM are 15-to-20 nanometers across. They are large enough to let individual lithium ions pass, but small enough to block the 20-to-50-nanometer tips of the fern-like structures.
The researchers made the membrane by layering the fibers on top of each other in thin sheets. This method keeps the chain-like molecules in the plastic stretched out, which is important for good lithium-ion conductivity between the electrodes, Tung said.
Dan VanderLey, an engineer who helped found Elegus through UM’s Master of Entrepreneurship program said, “The special feature of this material is we can make it very thin, so we can get more energy into the same battery cell size, or we can shrink the cell size. We’ve seen a lot of interest from people looking to make thinner products.”
Kevlar’s heat resistance could also lead to safer batteries as the membrane stands a better chance of surviving a fire than most membranes currently in use.
While the team is satisfied with the membrane’s ability to block the lithium dendrites, they are currently looking for ways to improve the flow of loose lithium ions so that batteries can charge and release their energy more quickly.
While the venture capitalists are looking for a major disruptive technology its quite pleasing to see a very innovative and creative idea offer a beneficial incremental improvement that may well be adopted into consumer products very quickly.
January 27, 2015 | 1 Comment
Jaeyoung Park, Chief Scientist at EMC2 presented the team’s work to date and explored the level of what’s needed to continue research to a net power electrostatic nuclear fusion reactor.
The presentation was given at the 16th U.S. Japan 2014 Workshop. This link here downloads the pdf file of Park’s presentation. It a very graphically rich and informative paper well worth the time for review.
The results are the team led by Park at EMC2 succeeded in achieving a time resolved hard x-ray measurement. That is a first from a theoretical conjecture first offered by Graf and his research team in the 1950s. It provides the first ever direct and definitive confirmation of enhanced plasma confinement in a high β cusp. (β is lower case beta Greek text. Without proper rendering support, you may see question marks, boxes or other symbols instead of the Greek letter.)
The team also achieved enhanced electron confinement in the high β cusp. This level of confinement is a basis for the Polywell fusion concept, that the late Dr. Robert Bussard proposed, to move forward to complete the proof-of-principle test.
Should a proof-of-principle effort get underway and prove the theory a Polywell reactor or fusor may be an attractive fusion device due to its native advantages. The advantages are stable high pressure operation with good electron confinement inside the β cusp and a Polywell would offer high ion acceleration and confinement by electric fusion.
Getting those two advantages operating together, the high β cusp and electric fusion, is the next step in getting to a net power producing Polywell fusor.
The presentation file offers us the slides without the narrative. So far at least the University of Wisconsin hasn’t seen to it to offer a video or text to go along with the slides. So we’ll have to surmise our way through in a brief summary of what we can see.
Park starts with a brief graphic and notes explaining electrostatic fusion and a electron confinement that make up a Polywell, which is what Dr. Bussard came up with in 1985. Over the course of a few pages Park explores the progress of what Dr. Bussard called the Wiffle-Ball (WB). The basic WB has been through eight generations so far.
The previous generation, seven, was the last to be built with the six electromagnets joined together at their closest points. The device did prove up the previous WB results and showed the necessary neutrons.
The last generation, number eight, has to major improvements. The first is the electromagnets are held in place by an external frame. The other is the first plasma source uses an arc to initiate a high density plasma into the central core of the box shape of electromagnets.
Now we’re at the point, page 13, where the narrative is critical for understanding what took place during the presentation. What we can see is the history beginning in 1955 and running to 1977 over 20 devices and 200 published papers about electromagnetic confinement. By 1980 the understanding and materials simply did not suggest a route to a operating fusor.
But Dr. Bussard had that idea in 1985.
The presentation goes into the recent experiments at EMC2 with a striking set of photos and graphics showing the facility, installation, device layout, the devices, and instruments.
Then the presentation shows illustrations of the experiments reviewing the plasma injection, x-ray emissions and the x-ray sensor.
The presentation slides are then a set of graphs that illustrate the results and a bit of guidance on how to interpret the results.
There are two main unresolved matters for the next stage of research. The confinement decays while in use. Finding out just why isn’t possible as the potential of the current WB is maxed out. More depth of understanding is needed about the magnetic fields while the fusor is running. It would seem, although we don’t know for now what Park said, that there must be room for improvement in the materials and fine tuning of the magnetic fields.
For those starved of information on Dr. Bussard’s theory, the progress at EMC2 and where the WB fusor is at in its development, the presentation is a huge windfall well worth one’s time to review.
The next and most concerning question is, can the next step find its funding? The EMC2 WB is a much larger potential fusor than say the elegant Focus Fusion device. A WB at commercial scale would be a very productive low cost base load power unit.
For now we’re hoping the presentation was recorded and a YouTube video comes out. It would also be worthwhile to know someone is actively seeking funding. For now EMC2 is missing the CEO leadership personnel. Its a huge role to fill.
Thanks to Brian Wang at nextbigfuture.com for finding the presentation file.
January 22, 2015 | Leave a Comment
Researchers at the Institut Charles Sadron, University of Strasbourg in France have made a polymer gel that is able to contract through the action of artificial molecular motors. The effect is similar to the linear motion of a muscle contraction. This might be the first artificial muscle.
When activated by light, these motors twist the nanoscale polymer chains in the gel that as a result contract by several centimeters.
Plus, the new material is able to store the light energy it absorbed.
In a living organism individual muscle cells make structural motion that has an effect at the macroscale, such as a muscle that contracts via the concerted action of the combine cellular protein motors.
In order to reproduce this phenomenon, a team at CNRS’s Institut Charles Sadron led by Nicolas Giuseppone, professor at the Université de Strasbourg, has made a polymer gel that is able to contract through the action of artificial molecular motors. When activated by light, these nanoscale motors twist the polymer chains in the gel, which as a result contracts by several centimeters.
In life forms molecular motors are highly complex protein assemblies that can produce work by consuming energy. They take part in fundamental biological functions such as copying DNA and protein synthesis at the smallest scale, and underlie all motion processes in the large scale. As individual cells, the motors only operate over distances in the region of a nanometer. But when millions of them join up they can work in a completely coordinated way, and their actions have an effects at the macroscale.
Chemists have sought for many decades to produce this type of motion using artificial motors. To achieve this, the researchers at Institut Charles Sadron replaced the gel’s reticulation points, which cross-link the polymer chains to each other, by rotating molecular motors made up of two parts that can turn relative to each other when provided with energy.
For the first time, they succeeded in getting the motors to work in a coordinated and continuous manner, right up to the macroscale: as soon as the motors are activated by light they twist the polymer chains in the gel, which makes it contract.
Just as in living systems, the motors consume energy in order to produce continuous motion. But the light energy is not totally dissipated. It is turned into mechanical energy through the twisting of the polymer chains, and stored in the gel.
If the material is exposed to light for a long time, the amount of energy contained in the contraction of the polymer chains becomes very high, and can even trigger a sudden rupture of the gel.
The researchers at Institut Charles Sadron are therefore now attempting to take advantage of this new way of storing light energy, and reuse it in a controlled manner.
Its a good start. Perhaps there will be enough insight here to discover how to power and store with electrons someday. For now its quite an accomplishment. The possibilities are amazing.
January 21, 2015 | Leave a Comment
Study co-author Michael McGehee, a professor of materials science and engineering at Stanford said, “We’ve been looking for ways to make solar panels that are more efficient and lower cost. Right now, silicon solar cells dominate the world market, but the power conversion efficiency of silicon photovoltaics has been stuck at 25 percent for 15 years.”
One cost-effective way to improve efficiency is to build a tandem device made of silicon and another inexpensive photovoltaic material, he said. The research team described their novel perovskite-silicon solar cell in this week’s edition of the journal Energy & Environmental Science.
McGehee explains, “Making low-cost tandems is very desirable. You simply put one solar cell on top of the other, and you get more efficiency than either could do by itself. From a commercial standpoint, it makes a lot of sense to use silicon for the bottom cell. Until recently, we didn’t have a good material for the top cell, then pervoskites came along.”
Perovskite is a crystalline material that is inexpensive and easy to make in the lab. Researchers showed on 2009 that perovskites made of lead, iodide and methylammonium could convert sunlight into electricity with an efficiency of 3.8%. Today the efficiency is above 20% and attracting commercial attention.
Stanford graduate student Colin Bailie, co-lead author of the study said, “Our goal is to leverage the silicon factories that already exist around the world. With tandem solar cells, you don’t need a billion-dollar capital expenditure to build a new factory. Instead, you can start with a silicon module and add a layer of perovskite at relatively low cost.”
Silicon solar cells generate electricity by absorbing photons of visible and infrared light, while perovskite cells harvest only the visible part of the solar spectrum where the photons have more energy. “Absorbing the high-energy part of the spectrum allows perovskite solar cells to generate more power per photon of visible light than silicon cells,” Bailie explained.
But there is a kind of roadblock to building an efficient perovskite-silicon tandem, its a lack of light transparency. “Colin had to figure out how to put a transparent electrode on the top so that some photons could penetrate the perovskite layer and be absorbed by the silicon at the bottom,” McGehee said. “No one had ever made a perovskite solar cell with two transparent electrodes.”
Perovskites are easily damaged by heat and readily dissolve in water. This inherent instability ruled out virtually all of the conventional techniques for applying electrodes onto the perovoskite solar cell, so Bailie did it manually. “We used a sheet of plastic with silver nanowires on it,” he said. “Then we built a tool that uses pressure to transfer the nanowires onto the perovskite cell, kind of like a temporary tattoo. You just need to rub it to transfer the film.”
For the experiment, the Stanford team stacked a perovskite solar cell with an efficiency of a 12.7% on top of a low-quality silicon cell with an efficiency of just 11.4%.
“By combining two cells with approximately the same efficiency, you can get a very large efficiency boost,” Bailie said.
The results were impressive.
“We improved the 11.4% silicon cell to 17% as a tandem, a remarkable relative efficiency increase of nearly 50%,” McGehee said. “Such a drastic improvement in efficiency has the potential to redefine the commercial viability of low-quality silicon.”
In another experiment with a better grade of cell, the research team replaced the silicon solar cell with a cell made of copper indium gallium diselenide (CIGS). The researchers stacked a 12.7% efficiency perovskite cell onto a CIGS cell with a 17% efficiency. The resulting tandem achieved an overall conversion efficiency of 18.6%.
“Since most, if not all, of the layers in a perovskite cell can be deposited from solution, it might be possible to upgrade conventional solar cells into higher-performing tandems with little increase in cost,” the authors wrote.
A big unanswered question is the long-term stability of perovskites, McGehee added.
“Silicon is a rock,” he said. “You can heat it to about 600º F shine light on it for 25 years and nothing will happen. But if you expose perovskite to water or light it likely will degrade. We have a ways to go to show that perovskite solar cells are stable enough to last 25 years. My vision is that some day we’ll be able to get low-cost tandems that are 25% efficient. That’s what companies are excited about. In five to 10 years, we could even reach 30% efficiency.”
For now the tandem stack looks like a huge potential boon to the low end silicon solar cell market, enabling closing the gap to the better ones an perhaps very little cost. Just how to apply the perovskites to better cells and get big gains is a questions a lot of folks are surely asking today.