Friday, February 09, 2007

Hydrogen Fuel a False Promise? Not At All!

BoingBoing recently linked to an article from The New Atlantis about why using hydrogen as a fuel source is not feasible. The main argument against hydrogen is that it requires more energy to produce than that hydrogen will release upon oxidation (burning). Their secondary argument against hydrogen fuel is that in order for hydrogen to power a car for the same length trip as the average gasoline powered car now-a-days would require a much larger and more dangerous fuel tank. Both the arguments are true but they are definitely not good arguments as to why we should not focus scientific and economic efforts into producing hydrogen as a fuel source. The rest of this post will be a rebuttal to those two arguments from The New Atlantis.
1. Hydrogen requires more energy to produce than it can release. True. However, this is not really a problem. In China a new type of high temperature nuclear reactor, called a pebble-bed reactor, has been developed that uses uranium embedded in graphite balls to heat helium gas. The gas can heat up to about 1600 degrees Celsius without causing a meltdown. In fact due to the physics of expanding gas the nuclear reactor is meltdown safe. This alone is great from an environmentalist perspective: it will generate a huge amount of electrical energy without producing any carbon dioxide. The uranium fuel, once used up, is then embedded in a form of silicon and is safe for at least one million years, virtually 100% safe from leaking into any lakes or rivers as is the worry with previous nuclear power plants that use water vapor to drive the turbines instead of helium. The high temperature that the reactor reaches, along with the massive amount of electrical energy produced, can be used to produce hydrogen gas from water. The energy gained from these nuclear reactors would be more than enough to create a sustainable supply of hydrogen as well as producing electricity for cities and cars.
2. The tanks required to store hydrogen will be too massive and dangerous for conventional cars. This statement is true if the car is being powered solely with pure hydrogen. However, rechargeable battery power is getting better all the time and the amount of fuel necessary to power an electric/gas hybrid car is dropping. Organic polymer technology is also getting to the point that organo-synthetic casings will be light enough and cheap enough to hold pressurized hydrogen. Finally, the promise of solid hydrogen fuel is lessening the worry of the ultra-cold, high pressure, hydrogen fuel tanks altogether. In Seoul, South Korea, a physics group has found that they can get hydrogen to bind to titanium with no energy input and extract it back out with very little energy. This solid titanium-hydrogen combination does not need to be ultra-cold or under high pressure either, which will hopefully lead to safe compact solid-fuel hydrogen tanks.
Toyota last year put some hydrogen fuel-cell cars on the streets and because of a partnership between GM and Shell even more hydrogen fuel-cell cars will put on the roads in the next couple years along with new fueling stations. Hydrogen and nuclear power derived electricity is the future for cars and all energy in general, it's time the public and government took this more seriously in order to prevent global warming and also to prevent wars over resources as is the case with Iraq.

Some of my sources and further reading:
Platinum Today - Hydrogen binding to platinum for solid fuel.
Wired Magazine - Pebble-bed nuclear reactors.
BBC - General Motors and Shell partnership.

7 comments:

Mullis said...

Ethanol... not just a beverage anymore!

Andrew said...

Unfortunately ethanol still gets converted into CO2, the main culprit of global warming. I think it makes a great alternative to gasoline because it is sustainable and definitely cleaner than gasoline but in the end we will still need to suppress CO2 emissions making electricity and hydrogen necessary.

marisa said...

what about other biofuels such as primary solid biomass? it has lower CO2 emissions, only releasing that which was chemically bound when created.
The European Commission has been looking into how biofuel use could count towards CO2 emission targets (especially cars) for years.

how would hydrogen fuel prove more efficient and/or safer?

Andrew said...

biofuel? I'm aware of biodiesel, is that different? Either way any carbon based product is going to release CO2. Ethanol does not release toxic nitrogen by products, it does not release nearly as much soot as gasoline, nor does it release as much carbon monoxide, but it still releases CO2. Hydrogen fuel would prove to be just as efficient if not more so because the bond energies between two hydrogen atoms is greater than the bond energies between carbon and hydrogen (103kcal vs 98kcal, which seems small but adds up after billions of bond breakages). Plus when two hydrogen molecules are oxidized they becomes two water molecules which is not a greenhouse gas.

Chris said...

i honestly wish this country would follow france's lead in nuclear power. forget about net power and such with ethanol and/or hydrogen, the net C02 produced (sure, there's some C02 removed in photosynthesis if we're talking about plant-derived ethanol) in the total process (from seed to extraction to processing to product) would seem to dwarf that of the total nuclear process. not to say that radioactive ores come from the ether or some jazz, but the overall C02 footprint seems so much smaller.

Andrew said...

Well, yeah, really it comes down to people's willingness to accept nuclear power plants as a means of generating electricity. I think the mentality of the masses is shifting as people see how important global warming is and how safe nuclear energy is if developed correctly, such as the Chinese pebble-bed reactors and thorium reactor plans in the Netherlands.

Ian said...

I'd like to see much greater advances in battery technology, not just for use with hydrogen power, but as a way to store electricity produced by nuclear power, which does have a much smaller CO2 footprint. Pebble bed technology seems to be the way to go.