Side-Lines

Plus, storing the stuff is problematic.

You need a lot more volume than gasoline to store the same amount of energy for hydrogen.

Hydrogen-rich fuels like propane and methane make more sense.

The article is correct in verything it says. However, it does not say everything. It is true that you can't get more energy from hydrogen has (H2) than it took to make the H2. But in the case of automotive propulsion, there is a lot more to the energy cycle than the article explains.

Modern auto engines are extremely efficient in combustion, approaching 99 percent. But most of the energy produced, about 80 percent, is wasted by making heat rather than propulsion. This amounts to a sunk energy cost that is entirely lost.

Harnessing this "lost" energy to reform hydrogen either from water or hydrocarbons literally provides hydrogen at no additional energy cost. The H2 produced can be used either to supply a fuel cell stack (this is GM's developmental approach, producing H2 from gasoline) or to be injected directly into the combustion chamber where it is burned.

In the latter case, the energy gained from oxidizing the H2 when the cylinder fires is not the point, and is not very much, anyway. What H2 does in the fuel-air mixture is raise the flame temperature of the combustion. This leads the car's electronics to lean the fuel supply and raise the compression ratio. Result? Significantly greater fuel economy for the same amount of propulsive energy.

However, retrofitting a car to do this is not a good idea. The problem of hydrogen embrittlement is just as the article described, plus burning H2 in the cylinders increases the water output in the exhaust, which brings forth its own problems. But for engines designed for this system, the benefits are potentially very great.

Another line with potentially great benefit in converting the gas or diesel into a plasma state upon injection into the combustion chamber. A plasma gas conducts electricity, which means that the spark plug's current is trnasmitted across the fuel-air mixture as efficiently as can be. The plasma process also breaks the large chains of gasoline or diesel molecules into much smaller chains, increasing combustion efficiency to minutely under 100 percent. And, according to Los Alamos National Labs, this system can be retrofitted to existing engines.

More here.

Thanks for the update, Donald. I like the different (and thorough) perspective you've added here.

Dang Gerald, you still don't have the right column stuff on the rss feed.

I have been thinking about this issue for a while. Here is something I figured out over the last few days.

Hydrogen, even liquid hydrogen, is so light that any given volume of it carries very little energy.

One liter of liquid hydrogen contains 71 grams of hydrogen. On liter of gasoline contains 118 grams of hydrogen, and on liter of diesel, 130 grams.

Of course liquid hydrogen costs lots of energy to make, is difficult to store (it will leak out of any container in a matter of days), and is 423 degrees F below zero, so be careful when handling it.

Compressed hydrogen is less dense than liquid, and kaboom.