Once again I read the canard of hydrogen as an alternative to gasoline, in the line "Ultimately, cars will be powered by hydrogen or electricity." Commercial hydrogen is as much an oil product as diesel or gasoline. Changing over to hydrogen would NOT move of us off oil as an energy source. While the use of hydrogen as an automotive fuel would likely reduce air pollution, it is not the alternative to oil. Hydrogen puts the hydro in hydrocarbon.

Worse, it is wildly dangerous stuff to be driving about with. Think of a bunch of Hindenburgs wandering down the freeway driven by the same yahoos driving cars. Hydrogen blows up. It is used for rocket fuel for good reason: it is blows up big. The slightest of sparks can set it off.

It is not a feasible fuel for a private auto.

The explosion concern is a canard. Gasoline and natural gas are both highly explosive. Burning hydrogen actually creates very little radiant heat, and if it leaks it will, unlike gasoline, disperse almost instantly. Overall a fire in a gasoline car is far more dangerous. And there are various designs -- carbon nanotube storage, for example -- that would further reduce or eliminate the risk of explosion.

There are a small number of hydrogen cars on the road today. It really isn't a big issue.

A perhaps more serious problem is that there would need to be a whole hydrogen-fueling infrastructure built to support it.

It is used for rocket fuel for good reason: it is blows up big.

Gee, I didn't realize the goal in rocket design was to make it "blow up big." You might want to check your logic on that one.

In fact the reason it's used for rockets is simple: lots of energy for the weight -- about three times as much as petroleum based fuels for example. When you're launching something into space, every ounce counts.

i see hydrogen as an excellent alternative only if it can be produced with clean renewable energy. think hydrogen generation in oklahoma where the wind comes whipping down the plains.

storage and delivery concerns will be easily overcome.

It's good relative to the fuel weight you're carrying, but the specific impulse of H2-O2 rockets is significantly less than for kerosene fuel, and solid fuel motors are even better in that department with the tradeoff that they're less controllable than liquids and can't do multiple burns in the same flight.

The bigger danger with Hydrogen cars might be the risk of a collision damaging a tank to the point that it might rupture into shrapnel due to the pressure of its contents and that those contents might be able to flash-freeze some of the car's contents if they don't ignite (not sure about the flash-freezing since the mass of the stuff is so low, but it'd likely purge the cabin of O2 in short order in any event), since the cars would likely have to carry liquified H2 in order to get very far on a tank.

Really, just the logistics of distributing liquid H2 as widely as we currently do with gas and diesel are daunting. Electric is definitely more likely just from a practicality standpoint.

The safety complaint is a red herring. Sure, I'm just going on what engineers have told me and it's possible that we could have a Titanic situation here, but really, do you think people liked the safety attributes of driving around with a tank full of gasoline when it was first suggested?

As for the hydrogen- I don't understand your point here. Yes, there is hydrogen in hydrocarbons, but I don't think many plans for hydrogen fueled vehicles count on extraction from hydrocarbons. Must ideas I have heard would rely on splitting the oxygen and hydrogen from ocean water. I'm not a chemist, but my impression has been that we don't quite have a good way of doing this yet (and it can be a very energy-intensive process in and of itself) and to me, this seems like the biggest obstacle of having wide-spread hydrogen fueled vehicle use.

When I wrote that hydrogen explodes big, I meant exactly what the comments indicated later: it contains more energy per weight than gasoline. Gasoline is not particularly explosive. It must be aerosolized first, hence the use of a carburetor or fuel injection. Dropping a lit match on an open barrel of gas will not cause an explosion. It will likely simply extinguish the match. One can also outrun, really walk, a burning trail of gasoline vapors. The same cannot be said of hydrogen. The smallest spark in the presence of oxygen and it will explode and do so with great energy, i.e., explode big.

I don't understand the reference to the Titanic. I think the Hindenburg is more applicable.

Hydrolyzing hydrogen from water is an energy intensive process and not a practical means of production. That is why it isn't used currently, despite a relative shortage of hydrogen. I doubt any amount of engineering is going to fix this as the energy requirement has to do with breaking the molecular bonds and a not a technical issue. Moreover, if we can generate the energy to create the hydrogen, why not simply transport, store, and use the electricity? Electricity is easily shipped and there exists an excellent infrastructure for doing so.

The best use of hydrogen and least dangerous, though still rather a problem, is in a fuel cell, sort of battery. Hydrogen fuel cells have not shown themselves to be any better and, in many ways, worse than other batteries. Frankly, a lithium ion battery is longer lasting, more stable, more energy efficient, and easier to produce. The only advantage a hydrogen fuel cell might have is being able to refill the battery with fresh hydrogen, rather than needing to recharge it. However, a fillable battery uses moveable hydrogen, not hydrogen trapped in a fix material, so the safety of a battery is lost. If we could fix the cracking thread problem of lithium ion batteries and shrink the size of the wires needed, we'd boost their capacity several times. Stanford is doing some good work here. Devising an electrical storage medium is just an engineering problem.

In the end, with hydrogen, we have a very explosive and dangerous material that is only commercially viable when created as part of the oil and natural gas refining process. It simply isn't practical as an alternative, nor is it an attractive one. Until the First Law of Thermodynamics, that energy can neither be created nor destroyed, is repealed, hydrogen is not a green source of power, but one more product of petro industry.

yeah. my grandmama saw the hindenberg go down.

shut the fuck up john boy. this is 2008 and not 1936.

'Frankly, a lithium ion battery is longer lasting, more stable, more energy efficient, and easier to produce.'

how do you plan on charging them? with your taco bell burrito farts?

I found a couple of ISPs: Sea level ISPs, which are of course varied somewhat by expansion ratio were listed as 363 for H2-O2 and 350 for Kerosene LOX. I found a vacuum ISP of 453 listed for H2-O2, which I think is a pretty respectable number. I didn't go into great detail on this - I merely wished to see roughly how they compared.

I would charge them with electricity, of course. The great thing about electricity is the source can change with time and location, without changing the transportation infrastructure based upon an electric car. Hydrogen is either a petroleum byproduct, as it currently is made, and, thus, not helpful to ending our dependance on oil or it is produced by electrolysis, which is considerably less efficient at moving the energy of the electricity to the car. So, we can power a car with electricity, using Lithium ion batteries, focusing on creating clean, renewable power for all sorts of things, cars included, or we can use hydrogen, that is another oil trap, dangerous, and requires a vast, new infrastructure. Hydrogen is a fantasy, not a solution.

It is true that, because natural gas used to be cheap, it was the best way to produce hydrogen in industrial quantities. However, Naural gas is rising in price, and soon it will no longer be economical to produce hydrogen from natural gas.

In the future, hydrogen will be derived from either:

1. Coal(or organic waste) and Steam (coal gasification)

2. A chemical process like the Sulfur-Iodine cycle

3. High temperature electrolysis, which reduces the electricity required.

Just recently, a promising advance occurred in practical hydrogen storage:

<link>

That powder might help hydrogen find it's way into "consumer" uses.

But, frankly, consumer uses do not matter. We need more hydrogen research so that we can just plain stop using methane to produce our hydrogen.

Hydrogen is essential to production of nitrogen-based fertilizers, and we need to find ways to produce it cheaply without methane.

Hydrogen is not a primary fuel. It doesn't exist freely to recover as an energy source as does petroleum.

That said, it is a superior portable energy source for powering personal transportation vehicles. It is far less harmful to the environment than are fossil fuels, even if used in internal combustion engines. Even more so if used in fuel cells. We can easily overcome the safety issues involved in creating a Hydrogen distribution infrastructure and in carrying Hydrogen fuel on-board a vehicle. Hydrogen is abundant in nature and couldn't be considered a "finite resource".

The problem lies in the fact that significant energy must be expended in order to make Hydrogen fuel available. The same can be said of battery storage of electrical energy, and batteries are, by nature, dangerous devices constructed from non-renewable chemical resources.

What we need is technology that allows for inexpensive mass production of electricity from non-fossil fuel sources. When we fully implement the technology required to harness solar, wind energy and wave energy in the oceans and perhaps geothermal energy -- then the production of mass quantities of Hydrogen as a personal, portable fuel source will be economically feasible. By that time, we will probably be more interested in desalination of sea water than in personal locomotion fuel.

I foresee huge offshore facilities capturing energy from the Sun and the motion of sea water and converting that energy to Hydrogen and fresh water for onshore use.

I suggest that hydrogen is not really an energy source, but rather is a means of storage of energy derived from other sources. My feeling that use of hydrogen in internal combustion engines is at best and interim step, because of the inherent inefficiencies of internal combustion. The energy required to produce hydrogen would probably be much better utilized to drive electric motors instead.

I am more interested in fuel cells, etc than with the (IMHO impractical) idea of running our big SUVs on hydrogen fuel.

Fellas this discussion is already over, ever heard of Henry "Dad" Garrett, try looking him up on the net, he already built a HYDROLYTIC CARBURETOR, read about it <link>.

For you electric vehical lovers I got something for you too, read about Nikola Tesla and I promise you will be blown away, <link> to bad his best invention is lost to us.