Yes, unless you count fusion. But that's a completely different context.
You can fuse hydrogen, too. It's 'just' harder.
> Hydrogen gas is not naturally occurring on Earth, so by definition it cannot be a "natural" energy source. It's an intermediate product.
Not quite sure anything would count as 'natural' in that sense. Almost everything is processed in some way. I thought the problem was with 'energy source', not with 'natural'.
Since that storage was secure enough to contain the methane for a hundred million years, it can hold the CO2 just fine as well.
Rocks react quite well. Most are stable, some others absorb the gas and become stable.
It's water that doesn't deal well with it. It carries the CO2 into any place that it goes. What concerns me is that it's common to extract methane from places where it's trapped between a solid rock and a porous one full of water. That does not look like a proper place to inject CO2, but it's the place that every article about CO2 entrapment talks about.
CO2 sequestration is ready to go. Just like CO2 capture is ready to go. You have several actors commissioning projects now in Europe with 20-40 megatonnes stored per year.
AFAIK, that research did not make into the mainstream news. But then, geological research never does.
There is little need to store or transport hydrogen that may be produced right where and when it is needed.
I could imagine it as a viable storage technology, e.g. if you want to install a solar farm in a remote location you could have it produce hydrogen from the air and sell that.
Probably ammonia will be a better transport medium than hydrogen, but you need hydrogen to make ammonia.
We need ammonia for fertilizer, and right now we get the hydrogen for that from methane, which can't be the plan long-term. At the moment switching to hydrolysis would double to quadruple the cost of the hydrogen, but eventually falling electricity and rising natural gas prices should invert that. The Haber-Bosch process itself doesn't require petrochemicals, it's just the cheapest way to run it in the current market.
The intent of the method presented is to make electrolysis energetically cheaper. It might end up financially cheaper, depending on what the apparatus costs, which will of course start out high and come down if used much.
Apparently there are practical catalytic processes to go directly from N2 and H2O to NH3 and O2. Everything will compete, and a few processes will win. Tolerance of impurities in the water has often been a problem. Where you have to distill the water first, that increases cost.
In the future the world will use many, many times more, on top of all current uses producing steel, ammonia, and even methane, liquifying for aviation, and pushing underground to produce power from later.
The authors have no crystal ball. But need for lots of hydrogen is an easy call, and motivates better ways to produce it. Once produced, it will be used according to the needs of those producing it. The authors' speculations on such use do not bear on the value of the work.
This is a lie pushed by oil companies. First it is incorrect because hydrogen is not a natural energy source, it is a way to store energy. But above all, currently the vast majority of hydrogen is made by steam cracking methane or other hydrocarbons, which is a process that releases CO2. You can think of hydrogen production + hydrogen use as a combustion with additional steps. And since the hydrogen supply chain is very inefficient (hydrogen is very light so you need to compress it a lot to store it, it is a very small molecule so it leaks very easily, and when you use it you need to decompress it so you get more losses due to thermodynamic effects) it turns out as quite bad from the point of view of CO2 emissions. It is just a way to sell more oil.