Naked Science Forum
General Science => General Science => Topic started by: lex anderson on 24/02/2008 00:25:03
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I have been looking into a revolutionary form of Hydrogen storage called metal hydride. It was designed by Dr Roger Billings and in his book "The Hydrogen World View" he talks about this invention, as well as many other things. I have attached a link at the bottom.
Metal Hydride enables hydrogen to be stored at low a PSI (200 pounds per square inch or so). A 200psi tank of metal hydride can store up to 10 times the amount of similar tanks of compressed hydrogen at thousands of psi. I guess the metal hydride works like a sponge.
That right there would solve the problem of storing hydrogen, but Dr Billings also states that it is safer than typical fuels. They have conducted a test where they shot a charged tank of metal hydride with an armor piercing incendiary bullet. It pierced the tank, and shot out a flame, which quickly died down to a small pilot sized flame as the hydride slowly released the hydrogen.
It sounds like if you were driving down the road in your metal hydride car, and the tank split open spilling the contents out, you could sweep it up, put it back in the tank, weld it shut, and keep going.
It sounds pretty amazing to me. Does anyone else know about this?
The link to Dr Roger Billings' book is:
http://www.billingsenergy.com/Research.html
He also has a personal website at:
http://www.roger.billings.name/
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Metal hydride is not new, although which metal hydride, and how good it is at doing its job, is another matter.
Metal hydride technology is what is presently used in most rechargeable batteries (although the move is underway towards lithium ion technology from metal hydride technology).
At present, it has not been demonstrated that metal hydride is viable and a means of hydrogen fuel transport, although many consider it still shows promise.
One problem is ofcourse that all the great arguments about the high energy density (in terms of mass per unit energy) hydrogen provides quickly evaporate when you have to include the mass of metal hydride to contain the energy.
http://en.wikipedia.org/wiki/Hydrogen_storage#Metal_hydrides
Metal hydrides, with varying degrees of efficiency, can be used as a storage medium for hydrogen, often reversibly[2]. Some are easy-to-fuel liquids at ambient temperature and pressure, others are solids which could be turned into pellets. Proposed hydrides for use in a hydrogen economy include simple hydrides of magnesium or transition metals and complex metal hydrides, typically containing sodium, lithium, or calcium and aluminium or boron. These materials have good energy density by volume, although their energy density by weight is often worse than the leading hydrocarbon fuels. Furthermore, high temperatures are often required to release their hydrogen content.
Solid hydride storage is a leading contender for automotive storage. A hydride tank is about three times larger and four times heavier than a gasoline tank holding the same energy. For a standard car, that's about 45 US gallons (0.17 m³) of space and 600 pounds (270 kg) versus 15 US gallons (0.057 m³) and 150 pounds (70 kg). A standard gasoline tank weighs a few dozen pounds (tens of kilograms) and is made of steel costing less than a dollar a pound ($2.20/kg). Lithium, the primary constituent by weight of a hydride storage vessel, currently costs over $40 a pound ($90/kg). Any hydride will need to be recycled or recharged with hydrogen, either on board the automobile or at a recycling plant. A metal-oxide fuel cell, (i.e. zinc-air fuel cell or lithium-air fuel cell), may provide a better use for the added weight, than a hydrogen fuel cell with a metal hydride storage tank.
Often hydrides react by combusting rather violently upon exposure to moist air, and are quite toxic to humans in contact with the skin or eyes, hence cumbersome to handle (see borane, lithium aluminum hydride). For this reason, such fuels, despite being proposed and vigorously researched by the space launch industry, have never been used in any actual launch vehicle.
Few hydrides provide low reactivity (high safety) and high hydrogen storage densities (above 10% by weight). Leading candidates are sodium borohydride, lithium aluminum hydride and ammonia borane. Sodium borohydride and ammonia borane can be stored as a liquid when mixed with water, but must be stored at very high concentrations to produce desirable hydrogen densities, thus requiring complicated water recycling systems in a fuel cell. As a liquid, sodium borohydride provides the advantage of being able to react directly in a fuel cell, allowing the production of cheaper, more efficient and more powerful fuels cells that do not need platinum catalysts. Recycling sodium borohydride is energy expensive and would require recycling plants. More energy efficient means of recycling sodium borohydride are still experimental. Recycling ammonia borane by any means is still experimental.
New Scientist [3] state that Arizona State University is investigating using a borohydride solution to store hydrogen, which is released when the solution flows over a catalyst made of ruthenium.
Hydrogen produced for metal hydride storage must be of a high purity. Contaminants alter the nascent hydride surface and prevent absorption. This limits contaminants to at most 10 ppm oxygen in the hydrogen stream, with carbon monoxide, hydrocarbons and water at very low levels.
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WHY do people get so excited about Hydrogen, per se? It's only another element with some useful properties. If you treat it as a magical substance you risk making some bad choices between options.
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no, the scientists that tested it in the first place took some risks. You do realize that hydrogen is the only thing giving gasoline it's POP, right?
There's no need for the carbon, or even the oxygen in ethanol. In small amounts, hydrogen has the same properties as either. Plus, hydrogen would decrease the amount of carbon released, since there would be no carbon in the first place.
NASA is already trying to freeze hydrogen and use it for "slush-hydrogen" engines.
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NASA is already trying to freeze hydrogen and use it for "slush-hydrogen" engines.
NASA have a huge budget and are not interest in economy or the environment.
The Hydrogen bonds have lots of energy, it's true. This accounts for the high energy content of Hydrogen as a fuel. However, combining Hydrogen with Carbon in molecules makes it a lot easier to store, transport and handle. You can't beat a can of petrol as a handy way of storing the means to get from A to B. If you are talking environmental then the answer is to go from A to B far less often!
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Wow, some of the hydride you were talking about sounds pretty expensive and scary?
The stuff I was referring to was Dr Roger Billings' blend of Iron and Titanium with a trace of manganese. It sounds much safer and cheaper than some of the stuff you were talking about.
It can store and release hydrogen easily, but slowly. It gives it to the engine as it needs it. However, in the case of a crash it will not blow up like a tank of gasoline would, making it much safer than gasoline or other hydrocarbon fuels.
The Fe Ti blend (Iron and Titanium) would be not toxic. The disadvantage is the weight. It is true that metal hydride is heavy, but compared to tanks of hydrogen at 2,000 psi, it takes much less space.
Also, if you have a fuel cell car, you only need 1/3 of the fuel to go as far as convention gasoline cars. So, even if it weighs more, you only need to store 1/3 of the fuel, so it help cancel that out.
Also, a Fe Ti blend would be quite cost competitive. Tests have been done that have successfully filled a hydride tank in a mater of minutes. It seems quite viable as a option to me.
I do not see the advantage of adding carbon in though. Is there a reason why you were suggesting that? Is there something particular you were thinking of, beside the fact that it is in use today?
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"no, the scientists that tested it in the first place took some risks. You do realize that hydrogen is the only thing giving gasoline it's POP, right?"
Sorry, but that's simply not true. Acetylene which has rather less hydrogen is more explosive than gasoline and it's perfectly possible to explode a mixture of coal dust and air with no hydrogen in it.
Most of this "There's no need for the carbon, or even the oxygen in ethanol. In small amounts, hydrogen has the same properties as either. Plus, hydrogen would decrease the amount of carbon released, since there would be no carbon in the first place." is nonsense too.
Please try to get to grips with the fact that hydrogen isn't going to solve the world's energy problems because it takes more energy to make the hydrogen than you can get back by burning it in an engine.
Last time I looked at this idea (hydride storage) there was another problem that got brushed under the carpet.
If you pump the hydrogen onto the metal to make a hydride there is a chemical reaction. This reaction gives out heat. In order to "refuel" the hydrogen store you need to get rid of this heat. The last estimates I saw were that, to get a reasonable refueling time, you would need to dissipate (ie waste) hundreds of kilowatts of energy. Not imposible but a right pain in the neck.
BT, re. "The Hydrogen bonds have lots of energy, it's true. " Actually, hydrogen bonds are relatively weak.
"Also, if you have a fuel cell car, you only need 1/3 of the fuel to go as far as convention gasoline cars. So, even if it weighs more, you only need to store 1/3 of the fuel, so it help cancel that out."
Care to supply some evidence for that claim?
" do not see the advantage of adding carbon in though. Is there a reason why you were suggesting that? Is there something particular you were thinking of, beside the fact that it is in use today? "
There are a couple of things in favour of this, first we already have the infrastructure for gasoline and secondly, while exotic metal hydrides might be very exciting, they are never going to be as easy as a tank full of petrol.
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The stuff I was referring to was Dr Roger Billings' blend of Iron and Titanium with a trace of manganese. It sounds much safer and cheaper than some of the stuff you were talking about.
I would scarcely call titanium cheap, although I understand that newer technologies may make it cheaper.
Whether Billing's material does as it claims is, like so many promising technologies, something for the future to prove.
It can store and release hydrogen easily, but slowly. It gives it to the engine as it needs it. However, in the case of a crash it will not blow up like a tank of gasoline would, making it much safer than gasoline or other hydrocarbon fuels.
In general, I am not questioning the safety of hydrogen; but you are wrong to say that other hydrocarbons are inherently explosive. Gasoline certainly is, but diesel fuel is actually very difficult to burn, and will not naturally explode.
The Fe Ti blend (Iron and Titanium) would be not toxic. The disadvantage is the weight. It is true that metal hydride is heavy, but compared to tanks of hydrogen at 2,000 psi, it takes much less space.
Agreed, but I would never consider driving around with a tank of hydrogen at 2,000psi either.
Also, if you have a fuel cell car, you only need 1/3 of the fuel to go as far as convention gasoline cars. So, even if it weighs more, you only need to store 1/3 of the fuel, so it help cancel that out.
As I have mentioned several times, fuel cells, apart from not yet being available with adequate power densities, are by no means exclusive to hydrogen, so comparing fuel cell hydrogen technology to fuel cells using another fuel is a more reasonable comparison to make, and the hydrogen rapidly becomes less attractive.
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Quote from bored chemist:
BT, re. "The Hydrogen bonds have lots of energy, it's true. " Actually, hydrogen bonds are relatively weak.
I'm not a chemist; where could I have got that idea from?
I thought it explained the high SHC of water and lots of other things.
Certainly Hydrogen has a very high 'calorific value' but I'm not in love with the stuff!
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Quote from bored chemist:
BT, re. "The Hydrogen bonds have lots of energy, it's true. " Actually, hydrogen bonds are relatively weak.
I'm not a chemist; where could I have got that idea from?
I thought it explained the high SHC of water and lots of other things.
Certainly Hydrogen has a very high 'calorific value' but I'm not in love with the stuff!
I assume Bored chemist, with "hydrogen bonds" intended those, e.g., among water molecules and not bonds of hydrogen atom with other atoms (which are much stronger). The previous infact has exactly the name "hydrogen bond".
http://en.wikipedia.org/wiki/Hydrogen_bond
P.S. What do all that acronyms mean? POP, SHC..?
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'pop' is a small bang!!!
SHC is Specific Heat Capacity.
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Hydrogen bonds are responsible for the high heat capacity of water, but the bonds between the atoms in water molecules together are a lot stronger. Water evaporates quite well on a warm day. It doesn't fall apart to give hydrogen and oxygen until you get to thousands of degrees.
BTW, Ti isn't cheap, but it's fairly common so that might not be a great problem.
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However, in the case of a crash it will not blow up like a tank of gasoline would, making it much safer than gasoline or other hydrocarbon fuels.
Cars in films always explode when they have a crash. In real life they seldom do, whatever fuel they work on.
Also, how energetically 'convenient' is it to tear hydrocarbons apart to just get to the Hydrogen? One of you Chemists can help me there, I'm sure.
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Convenience is one thing. Efficiency is another.
If you could strip the hydrogen from oil and burn it you would get some energy and some left over carbon. If you burned the carbon too you would get more energy.
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Yes - but the Hydrogenologists (homage to neilep) want Hydrogen in a can so they can use it.
Where does that leave us as far as Hydrocarbons are concerned when trying to get a can of Hydrogen?
Is it worthwhile?
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There are 2 ways to look at this (at least).
You can burn oil, generate electricity, electrolyse water and get hydrogen.
Or you can (with some difficulty) crack oil to give coke and hydrogen. The latter doen't generate so much CO2 but the former may, for a given amount of oil, give you more hydrogen.
Are we more worried about running out of oil or raising the CO2 levels?
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Mine was a nonsense question, really, but it does get the whole thing in perspective.
The George W. approach seems to want the same rate of consumption yet to improve the situation. Why not just go, in an intelligent way, for drastic reduction in energy use? It doesn't get votes, unfortunately.
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Mine was a nonsense question, really, but it does get the whole thing in perspective.
The George W. approach seems to want the same rate of consumption yet to improve the situation. Why not just go, in an intelligent way, for drastic reduction in energy use? It doesn't get votes, unfortunately.
Clearly, all systems have their inefficiencies, but beyond that, the only way you use less energy is to do less work, and that means to reduce the amount humans produce, and have an impact on our standard of living (which will also have an impact on both our quality and quantity of life).
As I said, you can improve efficiency a little, but even that is not without its cost, since increased efficiency usually comes with increased specialisation of function, which has a cost in terms of reduced adaptability. Clearly, a lot has been done in this direction (human activity includes considerably greater specialisation of functions than it did even a few centuries ago, let alone a few millennia ago; which is why most humans would be unable to look after themselves outside of the environment to which they have become specialised to, but the benefit has been far more productivity of society as a whole).
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that means to reduce the amount humans produce, and have an impact on our standard of living
Precisely; we either have to do something like it now, voluntarily, or be forced into something more drastic later.
Perhaps we need to think differently and not just in terms of "productivity is good". Perhaps "consuming less is good" might get us somewhere.
The extreme 'specialism' of the present western society is not many 100 years old. It is changeable - it may have to be. It depends whether we do it early or later.
Humans being human, it will probably mean large scale war and a high death rate.
There's cheery.
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that means to reduce the amount humans produce, and have an impact on our standard of living
Precisely; we either have to do something like it now, voluntarily, or be forced into something more drastic later.
Perhaps we need to think differently and not just in terms of "productivity is good". Perhaps "consuming less is good" might get us somewhere.
The extreme 'specialism' of the present western society is not many 100 years old. It is changeable - it may have to be. It depends whether we do it early or later.
Humans being human, it will probably mean large scale war and a high death rate.
There's cheery.
I agree, it may well be a question of whether it is now or later, but the same can be said of death, and that might well be used as an argument for suicide - death will take us anyway, so we may as well embrace it today rather than wait for it tomorrow.
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I can't believe that you would just wait for death rather than attempt to get out of the way of an oncoming truck. survival even for an extra day is most people's chosen option.
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I can't believe that you would just wait for death rather than attempt to get out of the way of an oncoming truck. survival even for an extra day is most people's chosen option.
That depends on knowing which direction the truck is coming at you from.
Also, it as important to know what you are jumping into as jumping out of (so as not to be jumping out of the frying pan and into the fire).
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You haven't answered the question; would you really just stand there? There is only a binary response permitted; yes or no.
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You haven't answered the question; would you really just stand there? There is only a binary response permitted; yes or no.
Sorry, it is not a binary response.
Jumping is the easy bit - but jump to where, or even when to jump?
First you asses where is safe to jump, then you make sure that the truck is actually heading for you.
As an absurd example, but only absurd because we understand a lot about trucks and the environment in which they normally operate: we could be standing at the side of a bend in the road, see the headlights of the truck heading towards us, so we jump into the middle of the road to get out of the way, and get run over.
Ofcourse, I suppose if I knew nothing about trucks at all, then why should I fear them as a potential life threatening risk anyway; so the analogy only works if one assumes a certain knowledge about the environment you are working in.
Ofcourse, if one assumed one knew everything about the environment, then one would carefully step off the road long before one needed to jump out of the way (but stepping off the road is not necessarily the same as avoiding the immediate trajectory of the truck).
In an emergency situation, if one knows the environment well enough, it might even simply be best to lie flat between the wheels of the truck (although it assumes we are talking about a large truck) than trying to jump out of the way, but not quite jumping far enough (possibly you have steep inclines on the side of the road, or the truck is too wide and too close to jump), and finding yourself aligned with a wheel of the truck.
So I am not saying one should not defer death, but to do so, one has to make calculated judgement, and not panic reactions.
The point is that your own comment accepted that any significant reduction in social productivity could lead to war, and accepted that sooner or later social productivity would fall - the question seemed to be whether we wished to artificially reduce social productivity today to naively believe this will defer the reduction of social productivity later. Try running a company at a slight loss because you know that high profits cannot last forever, and you will quickly find that the slight loss will quickly accelerate to a large loss. I accept there are risks in over stretching one's expansion, but not over stretching one's expansion is not the same as engineering a long term or perpetual loss.
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If you spent so long thinking it over, I fear the truck would have hit you by now! A great loss to us all.
I think you misread my shorthand scenario.
I am saying that we need to do something about it soon. The only reasonable something is to use less energy by actually consuming less. It cannot have any adverse effect on out environment so it is a safe direction in which to amble as the truck is on the horizon. I am also assuming that there is not enough juice in the efficiency lemon to make any significant difference. Reducing productivity would not be a popular strategy. In fact it is probably impossible to think of it as a likely, voluntary course of action, certainly not for a developing nation. That means heavy persuasion on the part of some powerful nation or group. That's where my war scenario comes in.
And, if and when things get really tight, war will be a certainty.
Nonetheless, 'we' will have to make an effort - and 'we' will.
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I am saying that we need to do something about it soon. The only reasonable something is to use less energy by actually consuming less. It cannot have any adverse effect on out environment so it is a safe direction in which to amble as the truck is on the horizon.
And I am saying there is no such thing as a safe option - all options carry risks, whether you see them or not. You may amble out of the way of the truck and walk over a precipice.
At least in Europe, human activity is such a dominant part of the environment, that simply doing less will also have an effect on the environment. Many species, from domestic animals, to urban foxes, seagulls and pigeons, to rats, are all dependent on human activity; so reduced human activity will effect them too. Ofcourse, reduced production of many medicines may assist many human pathogens. Whatever you do will have winners and losers, and even doing less will have winners and losers, so the notion that it is a low risk option is naive.
Aside from that, from my own perspective, I have no particular direct interest in what has adverse or beneficial effects on the 'Environment', only on what had benefits to mankind; so if one can show that killing half the people on the planet may in some way benefit the 'Environment', I know which side I am on in that conflict of interest, and it is not the side of the 'Environment'.
I am also assuming that there is not enough juice in the efficiency lemon to make any significant difference.
I would agree with that.
Reducing productivity would not be a popular strategy. In fact it is probably impossible to think of it as a likely, voluntary course of action, certainly not for a developing nation. That means heavy persuasion on the part of some powerful nation or group. That's where my war scenario comes in.
But the problem is that war will be won by the more productive society, not by the less productive society (war is one of the greatest consumers of resources, so if you have a society that does not have the mechanisms in place to allocate massive resources to war, you will lose the war, and will not be able to make your point).
Ofcourse, being on the losing side of a war, you have magnanimously given your life and well being in order to allow the winner more resources, those resources you may have otherwise used to further your life, and now are available to the other side to offset their shortfall having had to consume so much resource in fighting the war against you.
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So it's a lose lose situation.
Time to find a survivalist cave somewhere, I guess.
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So it's a lose lose situation.
In the long term, yes; the question is how one judges the timescale for this lose-lose situation to arise; and I am in that regard more optimistic than many.
There are ofcourse more short term problems regarding global shifts in the political and economic balance of power from the traditionally wealthy West to the newer economies in Asia, and this is without doubt painful; but I don't see this as a matter of running out of resources, only a matter of who has the power to grab the lion's share of them.