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Liquid Sponges Extract Hydrogen From Water
New submitter gaelfx writes: Researchers at Glasglow University have an interesting method for separating the hydrogen out of water: Liquid Sponges. Most methods of extracting the hydrogen involve some form electrolysis, but these generally require some pretty expensive materials. The researchers claim that they can accomplish this using less electricity, cheaper materials and 30 times faster to boot. With both Honda and Toyota promising hydrogen fuel cell cars in Japan within the next few years (other manufacturers must be considering it as well, if not as publicly), does this spell a new future for transportation technology?
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It still takes more energy to separate the hydrogen from the oxygen than it releases by reacting.
Do you mean, "Why not this instead of photosynthesis?"
And that's because hydrogen is chemically unstable and hard to store compared to sugars. Neither of those are good things for living creatures.
Neither article makes any claim of a need for chemical purity of the water. What would coarse filter + reverse osmosis levels of purity be insufficient?
Do you have a third source of information or is this baseless dismissal?
This ignores the big problem of hydrogen, leakage. Currently about 10% to 20% of all hydrogen produced is lost to leakage. This has serious environmental ramifications. Hydrogen leakage will cause bigger and longer lasting holes in the ozone layer. By making hydrogen production cheaper and easier it just makes the leakage problem worse. http://www.nature.com/news/200...
I don't want to do a sig now
The process uses a liquid that allows the hydrogen to be locked up in a liquid-based inorganic fuel. By using a liquid sponge known as a redox mediator that can soak up electrons and acid we’ve been able to create a system where hydrogen can be produced in a separate chamber without any additional energy input after the electrolysis of water takes place.
I am interpreting your first question as "Is the expense of electrolysis the main inhibitor of a hydrogen-fuel economy?" I believe the answer is "sorta, but not really." The cheapest way to get hydrogen is from natural gas. The problem is that the whole reason to move to a hydrogen economy is to become carbon-neutral. If you use natural gas mines, you defeated the purpose. So to that point, a cheaper form of electrolysis might help.
Your second question is really a chicken-vs-egg question. There's low demand, because there aren't hydrogen-powered vehicles. But that is because it is difficult to store the hydrogen with sufficient density to make a car that can travel a long-enough distance. Compressing it takes time, wastes energy, and makes the tanks heavy and expensive. The next generation of attempts stores the hydrogen chemically. But bear in mind that there is already a really really good way to store hydrogen chemically. In the US, we call it "gasoline" and it is great because all you have to do is burn it, and it releases the energy from the hydrogen-carbon bond! Awesome! Perfect! Right? Ooops, that darned carbon-neutral thing again...
And that's because hydrogen is chemically unstable and hard to store compared to sugars. Neither of those are good things for living creatures.
Exactly. Plants learned *that* lesson long before we did with the Hindenburg. (If you listen very carefully to the video, you can hear all the plants laughing at our naiveté in the background.)
It must have been something you assimilated. . . .
The next generation of attempts stores the hydrogen chemically.
I'm not sure if it qualifies as "the next generation" when it has been studied since well before my now-adult children were born.
Skepticism with respect to hydrogen exists in part because some of us have heard this tune before. Storage of hydrogen in metal sponges is nothing new, and they have some very nice theoretical properties, including reasonable volumetric energy density, which is a big problem for hydrogen.
Getting up to 1/5 the volumetric density of fossil fuels--which is the likely upper limit--would make hydrogen cars more than competitive with electric vehicles. But so far no one has managed that, despite continuous work on the problem.
For some reason TFA doesn't say anything about the long history of storing hydrogen in metal sponges, or make clear what makes this one different, although one can guess that as a liquid there are likely metal particles in suspension and that gives a huge surface area advantage.
It's almost as if the articles were written by junior staff members with no actual knowledge of hydrogen storage technology, but since we live in a "knowledge based economy" where STEM skills are in incredibly high demand there is no way reputable news organizations like the BBC would do anything like that, right?
Blasphemy is a human right. Blasphemophobia kills.
You still need very pure water or you poison the process. Where's that water coming from? How do you collect the gaseous hydrogen? You still need to liquify it and all the emrittlement and cryogenic issues are still there.
Even if hydrogen gas is free, it makes no sense as an energy carrier for cars.
They don't collect the gaseous hydrogen in the electrolyzer; they soak it up with a "liquid sponge" ("a recyclable redox mediator (silicotungstic acid) " according to the article's abstract. In principle at least, hydrogen could be stored and transported in this form (a liquid sponge soaked with hydrogen).; the hydrogen can be catalytically released (wrung out of the liquid sponge) when needed. Whether such a system could be built with a practical size, weight, and cost for use in vehicles is another matter.
Not really. Natural gas is methane - CH4. It's about 35-85x more potent greenhouse gas than CO2. If you're converting methane to hydrogen, then converting that to CO2, you're not reducing the amount of carbon in the atmosphere, but you're still helping reduce the greenhouse effect.
All this is of course contingent on what would have happened to the methane if you weren't using it as fuel. Methane is primarily a byproduct of oil drilling. Until recently energy prices were low enough that it wasn't cost-effective to capture it, so oil companies just burned it as it came up the wells (those fires you see on top of long poles at oil fields). So since it was going to be converted to CO2 anyway, converting it to hydrogen to be used in fuel cells is actually carbon neutral. If oil production drops enough that we need to drill for methane specifically to keep up production, then it starts being carbon positive.