Posted on 09/11/2005 8:16:41 AM PDT by grundle
http://www.sciencedaily.com/releases/2005/09/050907102549.htm
Date: 2005-09-08
Danish Researchers Reveal New Hydrogen Storage Technology
Scientists at the Technical University of Denmark have invented a technology which may be an important step towards the hydrogen economy: a hydrogen tablet that effectively stores hydrogen in an inexpensive and safe material.
With the new hydrogen tablet, it becomes much simpler to use the environmentally-friendly energy of hydrogen. Hydrogen is a non-polluting fuel, but since it is a light gas it occupies too much volume, and it is flammable. Consequently, effective and safe storage of hydrogen has challenged researchers world-wide for almost three decades. At the Technical University of Denmark, DTU, an interdisciplinary team has developed a hydrogen tablet which enables storage and transport of hydrogen in solid form.
“Should you drive a car 600 km using gaseous hydrogen at normal pressure, it would require a fuel tank with a size of nine cars. With our technology, the same amount of hydrogen can be stored in a normal gasoline tank”, says Professor Claus Hviid Christensen, Department of Chemistry at DTU.
The hydrogen tablet is safe and inexpensive. In this respect it is different from most other hydrogen storage technologies. You can literally carry the material in your pocket without any kind of safety precaution. The reason is that the tablet consists solely of ammonia absorbed efficiently in sea-salt. Ammonia is produced by a combination of hydrogen with nitrogen from the surrounding air, and the DTU-tablet therefore contains large amounts of hydrogen. Within the tablet, hydrogen is stored as long as desired, and when hydrogen is needed, ammonia is released through a catalyst that decomposes it back to free hydrogen. When the tablet is empty, you merely give it a “shot” of ammonia and it is ready for use again.
“The technology is a step towards making the society independent of fossil fuels” says Professor Jens Nørskov, director of the Nanotechnology Center at DTU. He, Claus Hviid Christensen, Tue Johannessen, Ulrich Quaade and Rasmus Zink Sørensen are the five researchers behind the invention. The advantages of using hydrogen are numerous. It is CO2-free, and it can be produced by renewable energy sources, e.g. wind power.
“We have a new solution to one of the major obstacles to the use of hydrogen as a fuel. And we need new energy technologies – oil and gas will not last, and without energy, there is no modern society”, says Jens Nørskov.
Together with DTU and SeeD Capital Denmark, the researchers have founded the company Amminex A/S, which will focus on the further development and commercialization of the technology.
Ammonia is 3/17 (17.6%) hydrogen; gasoline is a mixture, but can fairly be represented as octane, which is 18/114 (15.8%) hydrogen. This "tablet" must contain some kind of structural matrix that absorbs - and therefore dilutes - the ammonia, reducing the hydrogen content by a significant amount.
H2 gas is impractical and dangerous - in order to store the same amount of hydrogen as is contained in a gallon of gasoline in the same space, a pressure of nearly 20,000 pounds per square inch would be required - nearly ten times what is considered high pressure for commercial tank gases. But what about the hydrogen fuel used on the Space Shuttle? That is LIQUEFIED, which requires cryogenic temperatures - unimaginably cold, and far beyond the capability of mechanical refrigeration equipment.
I believe that the "hydrogen fuel of the future" will be a pure, sulfur-free, synthesized version of gasoline. It will work equally well in internal combustion engines (spark and diesel) and as a hydrogen source for fuel cells via a "reformer" that separates the hydrogen from the carbon. The reformer technology is well known, as is the fuel cell technology.
But the raw material source might NOT be the crude petroleum we use today. The world has gigantic deposits of coal, tar sands, and shale, all of which are rich sources of hydrocarbons and MOST of which are located in NORTH AMERICA!
It looks as if no one should post back to you because you have all knowledge and all answers!
And the rest here don't know a thing about thermodynamics, right?
With methane, the least amount of CO2 is formed with combustion.
And yes, no matter what fuel we use other than hydrogen, carbon dioxide WILL be one of the end products. Vegetable oil, butter, ethanol, coal, ALL produce CO2 upon combustion.
CO2 is taken up readily by growing plants, converting the CO2 to a carbohydrate, as starch, sugar, cellulose, or any of a number of similar compounds, which are essentially storehouses of energy until consumed by some other life form. CO2 is an essential part of our own life cycle, an important little fact that the "greenies" seem unable to recognize.
But if there is concern about CO2 as a "greenhouse" gas, its importance pales almost to insignificance compared to one other that is rarely mentioned as a "greenhouse" gas - water vapor. The evaporation, movement and precipitation of water vapor has VASTLY more to do with weather and climatic conditions than CO2 ever could.
Difference is, water vapor is impossible to manage, while MAYBE a very small amount of control MIGHT be exerted on the production of CO2.
All of which disappears in the cloud of smoke that appears over just ONE erupting volcano.
Well, no. The processor that converts the ammonia to hydrogen is probably nothing more than series of metal screens, made out of some kind of catalyst. Or it might resemble your catalytic converter. Other than a pressure regulator, nothing that is not already in your engine is required to burn the hydrogen, in fact you can do away with the fuel injectors, fuel pump, fuel pressure regulator and fuel filter. It would be no different than a conversion to burn natural gas, which many fleet vehicles already do, although the ignition timing curve would probably have to be reprogrammed a bit.
Currently a common process for creating ammonia, the Haber Process, reacts Nitrogen (from the air!) with hydrogen () in the presence of a porous iron catalyst to form ammonia. While hydrogen is most commonly made by steam reprocessng natural gas, that is not the only way to do it. Electrolysis of water is another method that can be used on an industrial scale, you just need enough electricity, as from a nuclear generation plant. Still another method uses just heat and chemical reagents, which get recycled in the process. The input is water and heat, the output is hydrogen and oxygen.
Both hydrogen and ammonia are not nice substances to handle. The former is hard to contain, because the molecule is so small, the latter was once widely used in refrigeration systems as the coolant, leaks and accidents resulted in many deaths. However gasoline is also not a nice substance to have around, but we manage that by the thousands of gallons, and that's *after* it has left the pipeline. Refineries routinely suffer explosions and fires.
Actually its made from nitrogen and hydrogen, but the hydrogen is generally made from natural gas, but that is far from the only possible method, just the most economical using 19th century technology.
-- wraps up all that really needs to be said about the "hydrogen economy"--
An interesting development. I have long been in favor of developing alternative power sources for mainly national security reasons. This could be a step in the right direction...or it could just be a misstep. Either way, it is good to know research is going on.
So instead of pumping gas you pump ammonia. How often have you gotten a little gasoline on your skin? So long as there are no sparks its no big deal. You DON'T want to get anhydrous ammonia you your skin; it will burn holes in you.
Since water is 66% H2, when can I fill up my SUV with my garden hose?
barbra ann
--just need to treat it with a little electricity ( and do a few other steps) first---
there's alot of research going on about storing hydrogen in metals. Some metals like lithium can absorb gobs and gobs of the stuff, then release it back when they are mildly heated.
It can also be made from urine.
Ammonia is not good stuff either
Let's not go there.
Your text arkie2: ,,This would definitely be a step in the right direction but there's no mention of the technology or cost of encapsulating the hydrogen. Also, if the primary source of the encapsulated hydrogen is natural gas I don't see how that helps solve the energy crisis."
As there is much more abundance of natural gas than there is of oil (easily available that is) both in the world, and for you guys in the US, it helps to solve the energy crisis big time. Of course it will still pollute CO2 into the athmosphere, though it will not be as much in the cities but where the reforming of the natural gas to hydrogen is made, preferable outside of the major cities.
But the hydrogen can come from other sources, it can be created using energy and water, but we still do not have the renevable power sources to do that (except my country, but not the rest of the world) so in that respect you are correct, the energy crisis is stil not solved. But hydrogen can be created I beliewe by all kinds of biomass, similar to how biofuel can be created.
And there is the trouble, probably it is more rational to use this biomass straigth away as fuel, without the trouble of converting it into hydrogen and store it weather in metal hydrates, in ammoniak pills (did they not say they would use some borehydrat in them also?), liquid or gaseous form.
But then it would not be as energy efficiant, and not as many sources of energy could be used to create the fuel, like Iceland´s reneveable power sources of waterfalls and geothermal energy, or maybe future sources of solar, wind or other sources. But maybe those are just pipe dreams, and MainFrame65 is correct.
Not correct. Burning hydrogen creates water vapor, which is the number one greenhouse gas.
Of course, that system was enclosed, with calcium chloride (road salt) as the gas storage medium.
There will be little more water vapor generated than there is now burning hydrocarbon fuels. There will be biological sources that can generate ammonia form waste as well as vegetable matter. The processes will involve genetically modified or constructed organisms.
We are not far from this if we work hard at it and $60 oil is a heck of a prod.
Dr Cat: Take your hydrogen tablet and call me in the morning!
Actually, we have a gas shortage in the U.S. as well. That's why the major oil companies have been planning huge LNG vaporization facilities, so that gas can be imported to the U.S. from overseas.
This results largely from refusing to build nuclear or coal-fired power plants.
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