New Way to Make Hydrogen

zymano writes "Hydrogen is expensive to make and difficult to store. The most common way in making hydrogen is electrolyzing pure water. A new startup is trying a new way to make hydrogen. The process uses sodium which industry shuns because it generates sparks and heat when mixed with water. Signa has devised a way to mix sodium with silica gel or crystalline silicon to create a powder that essentially strips electrons from the sodium molecules in advance and stores them. When water is introduced, the chemical reaction proceeds calmly. The powder generates hydrogen efficiently. More than 9 percent of a kilogram of the powder gets converted to hydrogen and little energy is lost through heat."

Comments

Yes, but how efficient overall?

[dbloodnok]

This process may be efficient, but sodium doesnt grow on trees (or mined out of the ground). The easiest way to get it is.... electrolysis of sodium chloride.

So you've just shifted the electrolysis problem further upstream and instead of using nice friendly water, you're passing current through nasty, mean molten salt.

Re:Yes, but how efficient overall?

[Tatarize]

You are taking a highly efficient easy to transport form of energy (electricity) and using it to perform electrolysis of water (or in this case salt) and then going through a bunch of other steps to end up back at electricity. H2 is really hard to transport, and so long as it takes electricity to make, it's going to be less efficient than just putting the electricity right into the car. And by less efficient I mean way less efficient. It's really a gas so it's energy density is actually much less than that of gasoline. In fact, a gallon of gasoline has more hydrogen than a gallon of liquid hydrogen. Also, as a hydrocarbon you are burning, not only the hydrogen but also the carbon. Hydrogen is hard to transport, hard to use, hard to store, and hard to make. And we make it with the same stuff we want the fuel cell to make it back into.

As for your comments about NASA this argument is flawed in too many ways. First, hydrogen is used for electrical generation this is obviously true, but batteries just store energy. They are never used for electrical generation. Next we have the problem of scalability. Converting water to H2 takes electricity. And, for storage (if I am to understand) NASA would just store the H2 they could pull it off. There's a large energy loss converting from one form of energy to another. For NASA they can waste a bit of energy if it works out better for them in the long run. They can get the super expensive solar panels and use any amount of energy on land based operations if it saves anything in space based operations because even if it costs a boat load it will still be cheaper than doing it in space.

NASA could take a 40% loss in overall energy. Compare this loss with all the cars in the US. That's going to be huge. NASA is obviously a special case. They can use spend 20k dollars if it saves ten pounds they don't have to shoot into space.

Coal -> Electricity -> Hydrogen -> Electricity -> Kinetic.
or
Coal -> Electricity -> Sodium -> Hydrogen -> Electricity -> Kinetic.

Both of these suffer from the same problem. They loop through the same type of fuel (electricity). This is never going to work. It's too inefficient when we are talking about large scale deployment.

Coal (powerplant) -> Electricity -> Kinetic.
Solar -> Electricity -> Kinetic.
Gasoline -> Electricity -> Kinetic.
Biofuel -> Electricity -> Kinetic.
Hydrogen (assuming there's a major breakthrough) -> Electricity -> Kinetic.

From what I can tell here the argument is that hydrogen makes for really crappy batteries so we should use it as such. Even if this were the case the lack of fueling stations for hydrogen should mean that you should just replace your batteries with a closed system electrolysis/water/fuelcell battery, to store the energy. They would have to be secondary to actual batteries and just take in the overflow. Because, we aren't talking energy creation here, we are talking energy storage. In any case putting hydrogen into the car isn't really going to work out on a large scale. And if you're going to burn off that much energy in the process there's probably better ways to have such inefficient batteries.

And unlike hydrogen powered cars, my suggested design could start rolling off the lines next year.

Re:Yes, but how efficient overall?

[markov_chain]

Both of these suffer from the same problem. They loop through the same type of fuel (electricity). This is never going to work. It's too inefficient when we are talking about large scale deployment.

In theory though, they could still be more efficient than the internal combustion engines. See the following article on modern diesel engines, and note the projected fuel cell efficiencies which include fuel production.

Having said that, the modern diesels look like a serious contender to FCs, since they are already available, are competitive in efficiency, and yield well to hybridization. Once cleaner diesel fuel starts rolling in look out!

Uhhh Summary

[Ex Machina]

More than 9 percent of a kilogram of the powder gets converted to hydrogen and little energy is lost through heat.

Not to be overly pedantic but even though this may correspond to the yield, the hydrogen is originally part of the water, not the sodium.

Fossil Fuels...

[samtihen]

Being able to produce hydrogen in a way that does not use fossil fuels "at all" is a huge step in the right direction.

Another process in development involves bacteria that have a hydrogen waste product, if my memory serves me correctly.

Of course, solar, wind, and geothermal are also reasonable ideas.

The first person/company that is able to produce hydrogen cheaply using renewable resources will be an unbelievably good investment. (Assuming patents are taken care of properly)

Hydrogen is usually made from fossil fuels

[erl]

The story states:

"The most common way in making hydrogen is electrolyzing pure water."

From what I understand, this is wrong. I've heard that most hydrogen is ironically produced as a byproduct of refining oil.

Wikipedia for instance http://en.wikipedia.org/wiki/Hydrogen says that:

"Commercial bulk hydrogen is usually produced by the steam reforming of natural gas."

'Most Common Way'?

[pfdietz]

The most common way in making hydrogen is electrolyzing pure water.

Sorry, but this is just wrong. Millions of tons of hydrogen are made every year around the world (for ammonia synthesis, for example), and very little of it comes from electrolysis. Thermal reforming of natural gas and other carbonaceous compounds is much more economical.

Full of Errors

[Molecular Mechanic]

1) The most common source of hydrogen is hydrocarbon reforming, done at oil refineries. It's the only economically viable method for bulk quantities. Thus, hydrogen energy is currently dependent on fossil fuels.

2) You cannot electrolyze pure water -it's a poor conductor. You need some salt, or other electrolyte. Even then, the amount of electrical energy that goes in is less than the energy value of the hydrogen that comes out. And guess where most of the electricity comes from . . .

3) Sodium metal causes a fire when dropped into water because of the hydrogen it releases. The activation energy for the reaction between oxygen and hydrogen is very low, and the heat released from the sodium metal - being converted into sodium hydroxide (aka lye, or Drano)- is more than sufficient to cause the reaction (fire).

4) Sodium metal is made by electrolyzing molten sodium chloride (table salt). A very expensive, energy consuming reaction, not to mention nasty (it releases chlorine gas, also).

5) The amount of energy released when an electron is stripped from a sodium atom is the same, whether it's in water or in silica.The energy is either converted to heat or to some other form of energy. Ever hear of conservation of energy (or mass/energy for nuclear reactions)? Unless they've developed something that can do what the transporters and replicators on Star Trek do, the enrgy is still going somehwere. Entropy demands it, otherwise we'd have perpetual motion machines, and ebergy would not be an issue.

6) Mediating the reactivity of alkalai metals is nothing new - that's what amalgams do.

This story does not deserve the attention it has already received.

MM