Long long ago, when chemists were still Alchemists, and real men wore beards and magnificent mustaches (looking right at you Tycho Brahe), brilliant and methodical men wasted much time searching for the philosopher’s stone. This, for anyone without any fantasy knowledge, is some material (not necessarily a stone) that would transmute lead or other base metals into gold. Many times, this was also used as a metaphor for the philosopher/alchemist who sought some way to transmute their base instincts into noble characteristics. (See my poem: The Disappointed Alchemist)
The unattainable dream of the philosopher’s stone actually drove much invention, and yet it also caused much wasted time. I don’t mind that really, since alchemists were funded like any artist at the time, by people with money who wanted to look cool. Today’s alchemists, however, use taxes to fund their dreams, which is why I wanted to discuss one branch of research which is very common, and seems to be a modern philosopher’s stone: hydrogen power.
The appeal is certainly very large. Combustion, the simplest way to eke power out of nature is the rapid oxidation (with oxygen no less) of a chemical. For instance, the combustion of octane is written chemically like this:
Lots of carbon dioxide, and to make it worse, gasoline combustion is never this tidy. There are a massive number of different hydrocarbons in gasoline, some of which contain sulfur, nitrogen etc., giving as product (or exhaust) oxides of nitrogen, sulfur, and carbon monoxide. The appealing part about hydrogen combustion is that it yields no products other than water.
That means power with no pollution whatsoever! Which is, admittedly, a very attractive idea. Now, while technically possible, and definitely appealing, every chemist will readily admit many serious drawbacks. However, this blog is not for chemists, this is for non-chemists who have probably at some point read glowing articles in Popular Mechanics or Popular Science, or some article on the economy predicting the coming dominance of the hydrogen economy, and for those people, I want to lay out one of the theoretical difficulties with the whole idea. The other problems I list and the end because I am too tired to discuss them now.
Problem: Where do we get hydrogen? Well, right now we get hydrogen by putting a lot of energy into… methane… fossil fuels. This means that currently, to use hydrogen as a fuel we would have to take a pre-existing fuel, use energy to lower the energy density of the fuel, and then use the fuel. Not something anyone other than a bureaucrat would do. (Don’t get me started on Ethanol… ok, maybe sometime I will get there.)
Theoretical solution: This is the most philosopher stone like: water splitting. See the idea is this, use solar energy (it has to be not fossil fuel based to make any sense, so solar or nuclear energy is about it.) to drive a catalytic reaction that splits water into hydrogen and oxygen. The technical difficulties of water splitting are not really a subject I think I should go into here. In a nutshell, there are two distinct steps to the process, the hydrogen side and the oxygen side, and so far, every experiment is practically a proof of concept doing one side or the other and using massively expensive, typically non-reusable catalysts such as ruthenium based or rhodium or iridium based catalysts. (These are rare earth metals and very, very expensive.)
However, to me, the whole water splitting for hydrogen fuels looks like a big impossible circle.
Now I fully and unequivocally believe that scientists should try to do impossible things. Many times what seems impossible becomes possible because stubborn hard headed scientists keep trying to do them. That is perhaps one of the most admirable things about science, persistence in the face of overwhelming odds.
What bothers me is when people, scientists included, behave as if their experiments are funded magically, and that (more often than not in water splitting research) the concerns of those actually funding the work (taxpayers, not DOE or NSF or DOD) are unimportant. I believe that people, taxpayers, should know that things like this are very very improbable, and I also believe that if taxpayers do not want to fund something, they should not have to.
So, philosophically, I find the reasons for tax funding hollow. And as for those people who do not understand the scientific problems behind hydrogen (of which there are many others*) and yet proclaim it to be the ‘next thing’ and breathlessly tell us that as soon as we figure out distribution and sales, all will be well… those false prophets I find as ridiculous as Rabadash.
*1. Hydrogen Production (briefly discussed above)
2. Hydrogen storage (its nasty difficult)
3. Fuel cell or standard combustion efficiency
probably more… 🙂
Each part of the process is fraught with problems, and each step is used to justify many government grants… just so you know.