Getting Closer to Hydrogen as a Viable Fuel
Hydrogen is often held up as the fuel of the future, but there are some problems with good old H-2. First, it’s explosive. Second, as the lightest element, Earth’s gravity isn’t even strong enough to keep it here. Third, given one and two, rather hard to safely contain and if that isn’t enough, fourth … it isn’t that easy to generate. Yes, I did the electrolysis experiment in school using a battery to split water into oxygen and hydrogen, but the reality is that the amount of energy required to get the hydrogen out, exceeds the amount of energy the hydrogen releases.
Yeah not good. Okay to tackle the safety, storage and transport issues we have the hydrogen pellet:
Pacific Northwest National Laboratory, a U.S. Department of Energy research lab, has come up with a new formula for hydrogen pellets that looks like it holds a lot of energy, per gram.
The PNNL pellet is made out of ammonia borane, or AB, compressed into small pellets. A milliliter of AB weighs about 0.75 grams and can hold up to 1.8 liters of hydrogen. Researchers speculated that a fuel system powered by AB pellets will occupy less space and be lighter in weight than systems using pressurized hydrogen gas. That’s one of the pellets (and not a half-dissolved Jawbreaker) in the photo. Source: Another formula for hydrogen fuel pellets | Tech news blog – CNET News.com
This looks promising, but they have to work on getting the hydrogen back out easily, effectively, and cheaply. Now on the generation side:
Those mad scientists at Purdue University seem to think they have something big on their hands, with them now claiming that they’re “perfecting” a new hydrogen-generating technology that they first announced earlier this year. According to the researchers, the technology could represent a “pollution-free energy source” for a whole range of applications, with it effectively generating “hydrogen on demand.” To do that, the researchers added water to an alloy of aluminum and gallium, which attracts oxygen from the water, letting hydrogen loose in the process. Source: Engadget
Again anything to reduce the amount of energy require to liberate a quantity of hydrogen is a good thing. Again, more work needed.
See the pattern here? There are no easy answers. There are no quick fixes. It is going to take, time, money, and brains to get us to a place where we aren’t so dependant on fossil fuels. At least now I think we have the collective will to help make it all happen.
3 Comments
Aluminum and Gallium for generating Hydrogen? Hmm, that sounds pretty awful. Gallium is somewhat rare and somewhat expensive. Metallic Aluminum doesn’t occur naturally; it must be produced by electrolytic refining via the Hall-Heroult process:
http://en.wikipedia.org/wiki/Hall-H%C3%A9roult
and this takes a LOT of electricity. One of the reasons that Alcan established an Aluminum refining plant in northern BC was because of the ready availability of very large amounts of cheap hydroelectric power there.
Additionally, the Hall-Heroult process produces Carbon Dioxide as a byproduct (due to the chemical reaction of the anode in the electrolytic bath). Plus, the Hall-Heroult process requires some very high temperatures to keep the electrolytic bath molten.
Thus, I’m not sure if the production of Hydrogen by the Aluminum-Gallium reaction is all that great of an idea.
The Ammonia-Borane storage technique does look to have some promise, though.
Dave
Dave you always add such awesome stuff to the conversation! I think I’m just going to end posts with “Dave has this to say…”
And isn’t gallium freakin’ toxic too?
This is the balance isn’t it? What is the cost of the alternative?
No, Gallium isn’t all that toxic (although I still wouldn’t advise you to eat a kilogram (2.2 pounds) of it. You may be confusing it with Arsenic, which is the other material used to make Gallium Arsenide LEDs.
The real question is always about the entire system. You have to consider the cost of the precursors in addition to the results.
Dave