CORVALLIS, Ore. – Chemists and engineers at Oregon State University have discovered a fascinating new way to take some of the atmospheric carbon dioxide that’s causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.
This innovation in nanotechnology won’t soak up enough carbon to solve global warming, researchers say. However, it will provide an environmentally friendly, low-cost way to make nanoporous graphene for use in “supercapacitors” – devices that can store energy and release it rapidly.
Such devices are used in everything from heavy industry to consumer electronics.
The findings were just published in Nano Energy by scientists from the OSU College of Science, OSU College of Engineering, Argonne National Laboratory, the University of South Florida and the National Energy Technology Laboratory in Albany, Ore. The work was supported by OSU.
In the chemical reaction that was developed, the end result is nanoporous graphene, a form of carbon that’s ordered in its atomic and crystalline structure. It has an enormous specific surface area of about 1,900 square meters per gram of material. Because of that, it has an electrical conductivity at least 10 times higher than the activated carbon now used to make commercial supercapacitors.
“There are other ways to fabricate nanoporous graphene, but this approach is faster, has little environmental impact and costs less,” said Xiulei (David) Ji, an OSU assistant professor of chemistry in the OSU College of Science and lead author on the study.
“The product exhibits high surface area, great conductivity and, most importantly, it has a fairly high density that is comparable to the commercial activated carbons.
“And the carbon source is carbon dioxide, which is a sustainable resource, to say the least,” Ji said. “This methodology uses abundant carbon dioxide while making energy storage products of significant value.”
Because the materials involved are inexpensive and the fabrication is simple, this approach has the potential to be scaled up for production at commercial levels, Ji said.
The chemical reaction outlined in this study involved a mixture of magnesium and zinc metals, a combination discovered for the first time. These are heated to a high temperature in the presence of a flow of carbon dioxide to produce a controlled “metallothermic” reaction. The reaction converted the elements into their metal oxides and nanoporous graphene, a pure form of carbon that’s remarkably strong and can efficiently conduct heat and electricity. The metal oxides could later be recycled back into their metallic forms to make an industrial process more efficient.
By comparison, other methods to make nanoporous graphene often use corrosive and toxic chemicals, in systems that would be challenging to use at large commercial levels.
“Most commercial carbon supercapacitors now use activated carbon as electrodes, but their electrical conductivity is very low,” Ji said. “We want fast energy storage and release that will deliver more power, and for that purpose the more conductive nanoporous graphene will work much better. This solves a major problem in creating more powerful supercapacitors.”
A supercapacitor is a type of energy storage device, but it can be recharged much faster than a battery and has a great deal more power. They are mostly used in any type of device where rapid power storage and short, but powerful energy release is needed.
They are being used in consumer electronics, and have applications in heavy industry, with the ability to power anything from a crane to a forklift. A supercapacitor can capture energy that might otherwise be wasted, such as in braking operations. And their energy storage abilities may help “smooth out” the power flow from alternative energy systems, such as wind energy.
They can power a defibrillator, open the emergency slides on an aircraft and greatly improve the efficiency of hybrid electric automobiles. Nanoporous carbon materials can also adsorb gas pollutants, work as environmental filters, or be used in water treatment. The uses are expanding constantly and have been constrained mostly by their cost.
And that’s why this is interesting. It may be commercial as it’s cheaper and (they say) scalable.
But will it out-compete current battery technology?
Does anyone know how well supercapacitors can store a charge as opposed to take a charge?
“But will it out-compete current battery technology?”
No, but then it doesn’t need to, capacitors don’t compete in the same space as batteries because they are very different.
An ideal battery can be charged rapidly and discharged slowly, but an ideal capacitor is the opposite; it charges slowly and discharges rapidly.
Batteries and capacitors serve very different functions.
The only thing this needs to out compete is existing capacitor technology.
Depends entirely on what the capacitor is being used for. Many capacitors have to charge rapidly and discharge slowly. Others both charge and discharge rapidly.
but an ideal capacitor is the opposite; it charges slowly and discharges rapidly.
That is wrong. Ideal capacitor can be charged and discharged at any rate that is required. In some applications you need capability to supply very large current for very short periods of time, in some you need to be able to charge it very fast. Good super cap can do both.
Another thing about super caps is that they do not wear out, like batteries do – you can subject them to hundreds of millions of charge/discharge cycles and they do not change their capacitance. Also, over discharging doesn’t hurt them.
Rectifier? (for output smoothing = slow discharge)
0.4V across p/n junction multiplied by thousands of Amps. You really don’t want anything that will result in additional power dissipation.
I am thinking of something like a built-in inductor to limit max pulse current to something reasonable. The trick is to make it so it doesn’t get bypassed even in case of a failure of some unknown kind.
A capacitor can often charge and discharge at high rates, and because of that can augment batteries which often can’t charge or discharge as fast, but almost always have a higher capacity. In a hybrid car with regenerative breaking, the brakes often generate more electricity that can be used to charge the batteries, that extra electric energy can be stored in a super-cap, then be fed back into the batteries at a slower rate
I use a 1 Farad supercapacitor for my solar powered ham radio operation in parallel with a small AGM battery. The battery uses a chemical reaction to produce electricity, and charging it reverses the chemical reaction. But this reaction only proceeds at a somewhat limited rate. The radio needs current surges of 20 amps but most of the time operates at less than 1 amp. The capacitor stores charges across a dielectric (special kind of insulator), piling up electrons on one plate and removing them from the other plate with a very thin insulator between. Since no reaction takes place, it can load this charge as fast as the wires can take it and it can deliver that charge almost instantly.
So the capacitor “smooths out” the current demand, providing current during those peak demands that last only a few milliseconds and then between those demands fill itself from the battery, with solar power charging both.
1 Farad stores 1 Coulomb of electrons at 1 volt. 1 Coulomb is the number of electrons that pass a point if the current is 1 ampere. So, you can get 1 amp for 1 second from a 1 Farad capacitor if you charged it to 1 volt. A 12 volt charge will give you 1 amp for 12 seconds or 12 amps for 1 second. However, unlike a battery as you remove electrons its voltage will go down.
Other benefit: Since no chemical reaction takes place, the capacitor is not limited to a certain number of charge cycles. It does require a maintenance charge; if you let an electrolytic capacitor go all the way to zero charge for an extended period of time it may lose its dielectric insulator. A very gradual charge can restore the dielectric, called “forming the capacitor”, so if you have something with a big capacitor, such as a studio flash, be sure to turn it on occasionally or even leave it on. My big capacitor is permanently connected to its battery.
Since even a small gel cell battery can give you 7 amps for a full hour, that’s on the order of 3,000 times more capacity for a chemical battery as compared to a 1 Farad supercapacitor.
A special type of battery, called a Lithium Polymer (LiPo) has an incredibly high charge/discharge rate and these batteries are used in model airplanes and helicopters. A typical lead-acid battery wants a 1/10 C charge rate (one-tenth of its capacity over 10 hours charge rate) and can discharge at perhaps 2 C (full capacity discharge in 1/2 hour). But LiPo can produce 30 C, that means it can discharge its entire charge in 2 minutes. Tiny battery, really fat wires! I mean, seriously, 30 amps from a battery pack that could fit in your household wireless telephone. The fist-sized battery in a T-Rex 700 model helicopter delivers 2.7 kilowatts.
They are also rather dangerous and catch fire quite easily if you let them discharge below a certain point. Since they are made with lithium don’t even think about pouring water on it if it catches fire.
Good info, Michael.
A current ultracap delivers 10 to 100x power density of a battery, but only about 0.1x energy density. So it can load and unload at phenomenal rates, but cannot store not much total energy. A typical Maxwell ultracapacitor D size is 3100F at 2.3V or so (maybe even more by now). A 10X improvement basically solves the problem of energy density, but ucaps are still capacitors. So voltage drops to lower values quickly as opposed to chemical batteries which stay near constant until they drop at the end. So ucaps do well only with sophisticated power regulation and inverters, unless you couple with a battery. Together, you can get high current for a short time, and use a smaller battery. Cool stuff. I’ve had mxwl for a lot of years, still havent made or lost money. This could be a good catalyst since carbon purity is a very big deal. Making graphene cheap is the holy grail for ultracaps.
Patent pending?
*exhales*
Whoa! Perhaps I could sell them my exhalations?
Much higher CO2 concentration than plain old atmosphere.
they are flowing CO2 from a highly pure CO2 pressure tank reservoir over the metal reactants. Normal air at 21% O2/0.04% CO2 would simply oxidize the reactants, with no deposition of carbon from CO2 bond breaking. The purified CO2 comes from either 1) combustion of methane, 2) from ammonia production, 3) or calcining of calcium carbonate to make cement. Industrial scale commercial CO2 production from refrigeration-distillation to acquire atmospheric CO2 is quite a bit less efficient than the methods actually used. Besides the less C14, the better graphene lattice stability. Thus the use of fossil sourced carbon is better.
So, use of atmosphere derived CO2 would negate any cost efficiencies?
Most compressed CO2 comes from industrial air liquefaction/distillation used to produce compressed oxygen, nitrogen, argon etc. Compressed CO2 is commonly used for welding, beverages etc. and is very cheap.
Ahhh, while I was writing my comment below, you’ve expressed some doubts about their claim about lower cost, Joel. Good question; where will the CO2 come from?
They can pay more to get CO2 which has been extracted from the atmosphere, just as some people pay more to get electricity from windmills. I’d rather use only electricity from nuclear plants, but the electric company refuses to let me pay less in order to get only that electricity.
Commercial CO2 from non-atmospheric sources isn’t that expensive.
Commercial CO2 is made from burning natural gas. D’oh.
Damn., you beat me to it again. It is absurd to make any connection in this article with “atmospheric” CO_2 as nobody sane would use the latter concentrated through the use of human efforts by any means.
I was going to offer up my beer fermenter as a much better source. Yes, perhaps it is arguably “atmospheric” CO_2 that has been recycled into dextrins in barley, eaten as dextrose by a yeast, and transformed into alcohol and carbon dioxide as a consequence, but hey, it is high quality CO_2 in the end. Indeed, they could get their CO_2 by just popping the caps of the fermented-in-the-bottle brews themselves, and then enjoy the resulting slightly flat malt beverage afterwards.
Or, one could use the CO_2 pulled off of a fuel ethanol/methanol production process.
What one would be unlikely to do is burn coal to make it. Too many byproducts — CO, SO_2, nitrate/nitrites — and you will almost certainly end up with substantial contamination with leftover O_2 and N_2, as one isn’t going to burn 100% of the oxygen. Fermentation, OTOH, can produce nearly pure CO_2
rgb
Absurd to make the connection?? Ou, contraire, mon amis.
Scientific paper using a bottle of CO2 = no funding.
Scientific paper citing climate change CO2 = presto …. lots of funding.
Follow the money. Nothing gets a grant without mentioning Climate Change. You know the thing:
Abstract….
“New techniques for milling knurled flange brackets, and their effect on global warming…….”. Kerrrching!
“Aramid reinforcing in concrete foundations, and their effect of global warming…..” Kerrrching!
“Hormone advancement of the deer rutting season, and its effect on global warming….” Kerrrrching!
Ralph
.
.
And it tastes good as a bonus.
There is no Greenhouse effect – save inside actual Greenhouses – period!
Many times it is remarked in the comments of this post that there is no greenhouse effect. Yes, but there is an effect – some call it atmospheric effect. Trace gasses like CO2 are absorbing infrared rays from earth surface and emitting it in both directions again. 50% up, 50% down. This is something like a dampening effect against quick heat loss.
But – adding more trace gasses to the atmosphere seems not to increase this effect in real life – the temperature doesn’t just go up. Without any trace gasses we surely would live on a very cold planet, but from a certain concentration on the atmosphere has many other effects to compensate the insulating effect.
So the function is somehow similar to a greenhouse, but not the same. But in real live we often use wrong names for things and effects – it depends how we perceive them.
“Does anyone know how well supercapacitors can store a charge as opposed to take a charge?”
I don’t know the specific answer to your question, but I do know that storage is the biggest weak point in battery technology today, the one that everyone in the industry is struggling to solve. As someone pointed out, we have progressed immeasurably in every kind of technology over the last 100 years, save for one area – large scale electrical storage, where we are still barely ahead of the days of Edison and Tesla.
When that problem is solved, the world will be changed immensely.
(small batteries, such as for our hand held devices, have gotten quite good, but so far those improvements haven’t been scalable to the megawatt level)
Its not for the lack of trying so don’t wait for that “solution” … that when is a very big if …
“…atmospheric carbon dioxide that’s causing the greenhouse effect ”
If it weren’t for that danged CO2, there would be no greenhouse effect? And then everything would be great. Genuflecting at the alter of idiots.
I have to say that I was puzzled by the phraseology of using “…atmospheric carbon dioxide that’s causing the greenhouse effect ”!
Money quote.
How else are they gonna get paid?
Follow the money.
If it’s not related to AGW (however obliquely), it doesn’t get funding.
I understand (to a degree) just how big this apparent development is; but the field is arcane enough that it would never generate a headline outside of Electronics technical publications. It would be the same as announcing you’ve made a better AAA battery.
Interesting, indeed.
““There are other ways to fabricate nanoporous graphene, but this approach is faster, has little environmental impact and costs less,” said Xiulei (David) Ji, an OSU assistant professor of chemistry in the OSU College of Science and lead author on the study.”
Sounds like a winner. They didn’t re-invent the super capacitor. They just found a faster, cheaper process. That’s progress in my book.
Now if only the release could have left out all of the unproven-and-looking-more-doubtful-by-the-day CO2-based CAGW grant-assuring language… but, I suppose it was probably necessary for funding.
I recently read about research into Graphene being used to turn H2O into H http://spectrum.ieee.org/nanoclast/green-tech/fuel-cells/graphenebased-fuel-cell-membrane-could-extract-hydrogen-directly-from-air
put the two together and you have CO2 capture and Hydrogen cells the perfect funding storm….
This may or may not be a useful technological advance, but the amount of carbon it will remove from the atmosphere is surely trivially insignificant. Yet, this useless reduction in atmospheric CO2 is presented as a big selling point. Climate change is as much a religion as it is a science.
This will remove as much CO2 from the atmosphere as your cola does. IE, none. The cheapest sources of CO2 are from various chemical reactions.
Your cola derives its carbon dioxide from the fermentation off-gases produced at ethanol refineries. These gases are cleaned, filtered, compressed and distributed to the beverage industry. I’ve helped to design & build these gas harvesting systems for ADM and others, working with BOC Gases (now Linde). Carbon dioxide is an inherently valuable substance, it won’t be long before people are fighting over the stuff.
Oh I doubt it.
I say their CAGW is much, much more religion than science.
I’m not a fan of large scale super capacitor energy storage – its too dangerous.
Consider the following – a system of super capacitors designed to supply a gigawatt of power for a day, so perhaps a backup system for a 1 Gw wind turbine installation, to provide power on days when the wind doesn’t blow.
To supply a gigawatt for a day, the super capacitor system has to hold
1Gw x 1 day
= 1 Gw x 24 hours x 60 minutes x 60 seconds
= 1 Gw x 86400 seconds
= 86400000000000 joules of energy
By an interesting coincidence, this is similar to the amount of energy released by Little Boy, the nuclear bomb which destroyed Hiroshima – 75 Tera joules – http://en.wikipedia.org/wiki/Little_Boy
75000000000000 joules of energy
So if your super capacitor facility ever suffers catastrophic dielectric failure, as highly stressed capacitors sometimes do, the resulting energy release would be indistinguishable from a 16 kiloton nuclear explosion.
Are capacitors and/or batteries just poor ways to store energy. What about all of the lithium batteries in electric cars? I guess we just haven’t had auto accidents before the real dangers are exposed.
Note: The news just had a review of how dangerous lithium batteries are when being shipped by airplanes!!!
Given that the choice is between a lithium battery or a tank full of gasoline…
If we didn’t already all do it, there’s no way anyone would get away with the idea of driving around in vehicles with large tanks of highly flammable hydrocarbon liquids!
Nigel: A tank full of gasoline isn’t dangerous. In the real world, gas tanks only burn, they never explode. In fact the physics makes explosions pretty much impossible. Gas tanks aren’t sealed in the first place, in the second place there isn’t enough oxygen in the tank to ignite the gas vapors.
Exactly Mark, when you look at the alternatives, a tank full of gasoline doesn’t seem so bad. Unlike a super capacitor power pack, a fuel tank is unlikely to deliver its charge of energy as a catastrophic sub millisecond explosion – usually it just catches fire. Bad, but not as bad as an explosion.
Joel, the atmosphere contains 1 part per trillion C14 – Other variables will cause imperfections before any are noticed from C14. The cost of distillation of air is shared by the industrial demand for other gases, N2, O2, and the noble gases – and hey, its getting cheaper and cheaper with increased CO2 emissions! Burning anything to get CO2 is likely not as clean a source as atmospheric. And the cost. Calcining limestone uses fossil fuels and makes lime which you better also have a market for. Unless you attach onto an existing lime kiln, the scale of your operation would be even less economic. Also, bad news for fossil fuels. They may have had their original C14 reduced to zero but they aren’t free of it. They use fossil fuel liquids for scintillants in detection of neutrinos.
http://www.talkorigins.org/faqs/c14.html
This and probably terrestrial radioactive decay of thorium, etc creates ‘anomalous’ C14 in coal and other fossil fuels naturally. I’m not sure if they correct for this addition in C14 dating – I rather doubt it. I’m sure neutrinos going through the atmosphere hitting CO2, methane and organics It would make the age of something younger than it really is. No, for industrial purposes, go for atmospheric distillation – it’s still quite cheap. BTW, I wonder if Ferdinand Englebeen has considered this arcane addition of C14 to the atmosphere? I doubt it too.
Oops sentence pasting error “It would make the age of something younger…. belongs after “…C14 dating – I rather doubt it.”
Hand on, it’s all about stored energy. Much like a dam. If a dam bursts, it’s a critical event, much like a bank of theoretical supercapacitors.
But dams have known failure modes, and extensive monitoring is done to look for these problems and get them fixed. Capacitors have known failure modes, too, and in the same way you can monitor individual capacitors and preemptively discharge and replace one that is approaching failure.
Off topic now, but many years ago I was a tenpin bowling mechanic, looking after the AMF 82-70 pinsetters. Those monsters had big AC motors to run the sweep and table, and the motors themselves used big capacitors to kickstart the motor rotation.
So, these are 1960’s technology, and the motor start capacitors were known as paper capacitors (because the insulator was a waxed paper). They would run for years, and occasionally you would notice that a motor would be a bit sluggish in starting, suggesting that a capacitor was on the way out. But, being a paper insulator, they could also arc through and fail catastrophically.
So, this one day a young family is bowling and I was on duty. It was a known slow day, so I was running the desk and looking after the machines. They were having some fun, and one of the kids bowled their ball. It rolls down, knocks over some pins and hits the back pad, triggering the machine to life. The sweep drops, and signaled the table to start it’s decent. The table start capacitor promptly exploded, blowing the shield off the machine and covering several lanes with confetti! But the kid’s face… “Did I do that?” was priceless!
That a dam is getting ready to fail can usually be determined days in advance. Is there technology that can detect the deterioration of capacitors several days in advance?
@MarkW,
A capacitor near failure exhibits changes in its electrical responses. It gets hotter, for example, for a given current. It also depletes faster.
It’s not cost effective to monitor this in consumer electronics. Modern equipment in general tends to be discarded for reasons other than component failure. For example, I have a wonderful old Mac (my treasured SE/30) that I’m replacing it’s capacitors in. But the SE/30 ceased to be a useful piece of equipment in the early 90’s. For the dozen or so caps I’m replacing, the additional monitoring would have not been worthwhile.
In the case of the dam, modern techniques can suggest months out that there is a problem. My father in law use to work for the local water utility, and did some of the measurements (using theodolites mostly). A dam was determined to be having a problem that could have led to failure, so it was strengthened and enhanced over a 5 year project. The failure projection was several years out; so there was plenty of time to act,
A nice cheap bomb with no radioactivity.
Just like with chemical storage of energy (gasoline, etc.) the difference is not in how much energy you have stored, but how fast it could be released. This is the difference between burning and exploding.
Anyone who dealt with pulsed cap line knows how dangerous they are. This is primarily because they can release their energy very fast – exactly like explosion does.
Supercaps are just not efficient enough (in energy storage/volume terms) and too expensive to be used as real energy backups. But if they ever got there, they could be extremely dangerous. I wonder if it is possible to design “intrinsically safe” super caps – with built-in fast charge and slow discharge, so there is no way to bypass that protection
Idiots are generally underrated.
They can do a lit more damage than we think they can.
I would think you would bank these in a way to limit the damage the failure of one capacitor would inflict. So while there could be a danger when 1015 joules are stored in a small space, it could be managed in several banks and bunkers to prevent an electrical induced mushroom cloud. (I wonder if it really would mushroom – dang now I want to take some of these out to a bomb range and try it!)
If these can be made light enough, electrical braking to store the energy in a supercap would increase the efficiency of any electric powered vehicle. One would then use the charge in the capacitor to do a big part of the work of getting back up to speed. Storing braking transients in a battery just isn’t very efficient.
One confusing thing about the design of these is that to realize the increased surface area it would seem that the separator/insulator and opposite electrode would have to lay into or follow the “hills and valleys” of the ridged graphene surface. If this were done chemically It would make sense that they would be stable, but mechanically how is that done? What am I missing?
In a standard electrolytic capacitor the insulator is produced chemically when the capacitor is charged, its an ultra thin layer of aluminium oxide – so they probably have some similar trick in mind for these capacitors.
Will it absorb Hydrogen and if so how much? Mick G From: Watts Up With That? To: mickgreenhough@yahoo.co.uk Sent: Wednesday, 3 December 2014, 14:01 Subject: [New post] Curious: Atmospheric carbon dioxide used to make super capacitors #yiv0477272998 a:hover {color:red;}#yiv0477272998 a {text-decoration:none;color:#0088cc;}#yiv0477272998 a.yiv0477272998primaryactionlink:link, #yiv0477272998 a.yiv0477272998primaryactionlink:visited {background-color:#2585B2;color:#fff;}#yiv0477272998 a.yiv0477272998primaryactionlink:hover, #yiv0477272998 a.yiv0477272998primaryactionlink:active {background-color:#11729E;color:#fff;}#yiv0477272998 WordPress.com | Anthony Watts posted: “From Oregon State University comes this odd bit of news. Once you get past the rhetoric of the opening lines, it is rather interesting.CORVALLIS, Ore. – Chemists and engineers at Oregon State University have discovered a fa” | |
@Eric: That’s the problem with energy storage in general. Almost any stored energy has the potential to be accidentally released in a much shorter time than planned. Hollywood aside, cars very rarely explode despite having a lot of stored energy in the form of gasoline. I’m a bit more nervous about hydrogen powered vehicles, and flywheels in vehicles (a big idea in the seventies) could be even worse. As an aerospace engineer, I’m sensitive about what happens when systems fail. I store energy for heating my home in hot water for the short term, and in unburned wood for the long term. Don’t see supercapacitors (or batteries) changing that any time soon.
Flywheels are a great idea for cars, so long as you only plan on driving in a straight line.
Not a problem if you mount with a vertical axis.
I had some stock in Satcon back in the 80’s. They were into flywheel storage and had some really impressive units the size of basketballs. Would have been great for stop and go jobs like postal delivery.
Didn’t know what ever became of them ’til now. They’re into utility size solar inverters, no mention of flywheels on their web site.
A vertically mounted foywheel car would be great fun on roller-coaster type of road…
flywheel
So what does this mean in terms of how close wr are to the flux capacitor? I need to go back in time and explain the flaws in using tree ring data for temperature reconstructions to someone I’ll just call Captain Obvious to protect myself legally….
@ Mike McMillan:
What is the survival expectation in a catastrophic flywheel disintegration? I would not want to be sitting on the plane of rotation mere feet from the wheel!
Joel O’Bryan
December 3, 2014 at 9:46 am
“A vertically mounted foywheel car would be great fun on roller-coaster type of road…”
They tried that on busses in Switzerland. Didn’t work too well.
It would be interesting to find out how often gratuitous references to so-called global warming/climate change are made in modern technical or scientific papers that have nothing at all to do with the climate.
Another metric of interest would be to review for papers that claim a connection to the climate ocnsensus but in reality have little or zero connection.
“It would be interesting to find out how often gratuitous references to so-called global warming/climate change are made in modern technical or scientific papers that have nothing at all to do with the climate.”
100-97 = 3%?
lol
My guess is Lew and Cookie would have used this paper in their research.
I really hope this research was not funded by the public. The obvious benefits are to the electronics industry’s bottom line and a correlation to climate change only exists in rhetoric, therefore propaganda.
Why not funded by the public?
If a commercial application comes up the Government could license or sell the patent.
But speculative research into novel material development is a common good that may not be provided by the short-term objectives of markets.
this was clearly research for a commercial application …
I agree on that aspect, M. If it helps NASA move forward, I see it as money well spent. I should have said not funded by climate research money instead of generalizing it as public money. Since no mention is made of what money line OSU used to support it, my comment was probably non sequitur anyway. I am aware and grateful that NASA contractors have made many discoveries that have brought us to the present state of technology and will hopefully continue to advance our lifestyles, free of political interference and pressure to follow consensus instead of skeptical scientific curiosity.
A capacitor charges and discharges at the same rate, the time constant being CR seconds.
The only constraints on how fast a capacitor can charge/discharge is the heat generated by the charge/discharge current flowing through the thin internal connecting wires.
The length of time the capacitor charge is held depends upon how effective the dielectric is, the higher its resistance, the longer time it take for the capacitor to ‘self” discharge.
That statement is only true if you ignore real-life effects. Ceramic caps are probably very close to this, but even they exhibit piezo effects that change capacitance and dielectric losses depending on direction of current flow. For anything like super caps who uses chemical process to form dielectric this difference could be very noticeable.
The time constant is not necessarily the same. Different charge/discharge circuits with differing resistors, coils etc will affect them.
Sorry that is obviously wrong. TC is the same Time varies
“This methodology uses abundant carbon dioxide…”
What a laughably useless piece of information. Of course it’s “abundant”, just as are lots of things, like nitrogen or oxygen. Getting it into the concentrated forms usually needed though is a different story though.
Pretty cool
“…a fascinating new way to take some of the atmospheric carbon dioxide that’s causing the greenhouse effect…” THERE IS NO GREENHOUSE EFFECT!!!
Sounds like they need pure CO2 for the process to work. I don’t know of anyone who is getting that from the atmosphere. Most companies that provide CO2 get it from chemical reactions.
You silly! You can only get CO2 from right wing conservative millionaires who want to destroy the planet and enslave the human race…like regular people can get it from chemical reactions! Snort! (Sadly required obligatory sarc mention)
Link for paper (paywalled)
http://www.sciencedirect.com/science/article/pii/S2211285514002274
“We discovered that hot molten Zn/Mg mixture reduces atmospheric CO2 to dense nanoporous graphene.”
Fourteen authors?
One guy did the work and 13 university apparatchiks needed to be on the paper as well.
Well, for all you nay sayers.
Suppose that you build your co2 collection facility and capacitor manufacturing facility (co-located) with a dirty coal generating facility and captured the co2 as emitted from the process. You get cheat energy and a capacitor bi-product that serves the needs of the green energy community without the need for sequestration. It looks like a win-win to me.
won’t be cheaper then … scrubbing CO2 is very expensive …
http://www.netl.doe.gov/File%20Library/Research/Energy%20Analysis/Publications/CO2-Retrofit-From-Existing-Plants-Revised-November-2007.pdf
BenS, here’s the DOE document on that collection process for perspective.
Speaking of battery high energy discharge. On the news in Vancouver a couple of weeks ago a Prious went up in flames in a high intensity fire. Cell phone video showed a very bright highly intense fire. It was a cab and the cabby said he barely had time to get out.
Lithium vehicle battery fires are nothing new, anymore. Also, lithium burns very intensely because it is extremely reactive with oxygen.
Just show me the prototype ready for mass production.
For now this innovation is added to my collection of all the other bright idea´s that failed to materialize into real world applications.
…“And the carbon source is carbon dioxide, which is a sustainable resource, to say the least,” …
But…but… this is INDUSTRY!! Therefore it’s EVIL!! It we start using it for industry, surely we’ll soon run out of it?
Graphene is very thin, we’re probably talking of only grams of carbon per supercapacitor. The reference to ‘taking carbon dioxide from the atmosphere’ is calculated to mislead and provided to get attention.
Pathetic.
Or funding !!
Much less than that.
And in a related development… http://www.designnews.com/author.asp?section_id=1386&doc_id=275811&itc=dn_analysis_element&cid=nl.dn14.20141203&dfpPParams=ind_183,industry_alt,industry_consumer,aid_275811&dfpLayout=blog
The big issue here is cost. While they say it cost less to produce the nanoporous graphene with this new process, graphene is still tens of thousands of times more expensive than activated charcoal to produce. So until the cost comes down many orders of magnitude or the efficiency of the capacitor increases many orders of magnitude it’s all academic. Or in the real world, worthless.
More wasted “research”. As temperatures drop in the coming years, with consequent reduction in food harvests, anybody suggesting CO2 be removed from the atmosphere may well be vilified.
If I had the choice, I’d rather eat than mess around with capacitors!
Capacitors can be great fun. I used to lecture apprentices on analogue and digital electronics. Some of the sneaky devils used to charge a large capacitor (size and capacitor 1986) and leave it on the bench. The first person to put their hand inevitably over the top connectors to pick it up …….. got a real buzz. LoL
We used to use a megger to charge a capacitor then toss it to an unsuspecting coworker. Great fun…
Udar December 3, 2014 at 11:27 am, yes these capacitors COULD be very different, but data sheets do not mention it, so I suspect I am correct.
Here is the 1st datasheet for a supercapacitor, it shows fully symmetrical change and discharge characteristics.
http://www.maxwell.com/images/documents/hcseries_ds_1013793-9.pdf
“Chemists and engineers at Oregon State University have discovered a fascinating new way to take some of the atmospheric carbon dioxide that’s causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.”
I see dense people.
Okay, I have to ask. since it seems to be obvious to everyone else.
What does that specific-capacitance diagram tell us? As the voltage cycles between 0V and 1V (because the dielectric breaks down outside that domain?) the charge goes between positive and negative? Why is that? And, since there’s hysteresis, what’s the diagram’s directionality, clockwise or counterclockwise?
It is sickening to see these otherwise capable people bring in atmospheric CO2 and its reduction, they know they are writing BS. And it diminishes their reputation, as they behave like con-men. Why would I trust the rest of their writing if they start with deception.
Maybe someone already pointed this out, it is cheaper to produce co2 than to pull it out of the air. In other words to get the co2 out of the air they would have to expend more energy ( producing co2 form burning fossil fuels) than what they extract.