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Friday, January 6, 2006

Hydrogen Boom or Bust?

I found a very interesting article at the Alternative Press Review. It covers a subject I know little, if anything, about -- the hydrogen economy. The author, Dale Allen Pfeiffer, argues that a shift toward hydrogen fuel is not all it's cracked up to be. What do you think?

Here's his opening salvo. Please visit his blog to read the article in its entirety.
There is a lot of talk about the hydrogen economy. It is at best naïve, and at worst it is dishonest. A hydrogen economy would be a pitiful, impoverished thing indeed.

There are a number of problems with hydrogen fuel cells. Many of these are engineering problems which could probably be worked out in time. But there is one basic flaw which will never be overcome. Free hydrogen is not an energy source; it is rather an energy carrier. Free hydrogen does not exist on this planet, so to derive free hydrogen we must break the hydrogen bond in molecules. Basic chemistry tells us that it requires more energy to break a hydrogen bond than to form one. This is due to the Second Law of Thermodynamics, and there is no getting around it. We are working on catalysts which will help to lower the energy necessary to generate free hydrogen, but there will always be an energy loss, and the catalysts themselves will become terribly expensive if manufactured on a scale to match current transportation energy requirements.

All free hydrogen generated today is derived from natural gas. So right off the bat we have not managed to escape our dependency on nonrenewable hydrocarbons. This feedstock is steam-treated to strip the hydrogen from the methane molecules. And the steam is produced by boiling water with natural gas. Overall, there is about a 60% energy loss in this process. And, as it is dependent on the availability of natural gas, the price of hydrogen generated in this method will always be a multiple of the price of natural gas.

Ah, but there is an inexhaustible supply of water from which we could derive our hydrogen. However, splitting hydrogen from water requires an even higher energy investment per unit of water (286kJ per mole). All processes of splitting water molecules, including foremost electrolysis and thermal decomposition, require major energy investments, rendering them unprofitable.

2 comments:

  1. It would require some innovative thinking to make it work, for sure...

    One way to harness energy to make hydrogen extraction possible is solar thermal processes. If you take a solar collector with an "enhancer" (essentially a magnifying lens) and focus the light down, you can easily get the power throughput you need to hit the required energy level.

    Also, if hydrogen were combined with solar/wind power to help make the electrolysis method less burdensome, we could avoid the incident pollution and start to shift away from the grossly inefficient method of energy extraction we use right now (burn it and use the byproducts to drive piston engines) for transportation energy use.

    *shrug* as long as we're talking about things that improve bottom line energy efficiency and reduce pollution, it is worth consideration

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  2. Floundericiousmi,

    Thanks for the input. While my knowledge re this type of science is EXTREMELY limited, I do agree with your suggestion of the need -- for a myriad of issues -- for innovative thinking.

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