Comment by kamray23 | Hacker News Reader

Comment by kamray23 | Hacker News Reader

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> I don’t normally come across a HN thread that reads so “cliquey” outside of the crypto community stuff… seeing this sort of stuff about Hydrogen is just weird.

Really. Hydrogen in general is just a weird prospect. Hydrogen from SMR of natural gas has like way higher emissions than just burning natural gas, and massively higher emissions than just using diesel. It has exactly zero uses energy-wise other than as a medium for moving a ridiculous amount of energy quickly. Makes it real nice in things like rocketry and real useless for anything else. The most efficient way to produce it is by using electricity and water, which can make a no-emissions solution for that one niche. If you use gas or oil for electricity, reforming is technically slightly more efficient. In any case, it's always worse than fossil fuels by themselves, unless you use green energy. And cramming greenhouse gases underground doesn't make the situation any better, which everybody knows but for some reason pretends is not true. Digging tunnels and caves and building facilities to store monoxide in is far worse than just burning fossil fuels as fuel in the first place. This is a fairly doomed industry, because it has no point in an environmentally sustainable future.

Heating, specifically in the north.

Hydrogen has potential to replace natural gas in area that need serious heating. Where I am standing it is currently very cold, days are short, and the sun is very low on the horizon. Electric heating is possible, but without any green power sources nearby that just means more burning fossil fuels, a horrible conversion of energy. And the electrical infrastructure needed to move sufficient power from sunny/windy areas to heat homes in the north would be immense. But "green" hydrogen shipped over the existing natural gas infrastructure could work. So in those circumstances where you need to move energy for purposes of heating, hydrogen has its place.

Yeah but, gas is more power-dense. Burning hydrogen made from fossil fuels, be it with microbes (more emissions) or SMR (less emissions) in any case produces more emissions than just burning natural gas.

Only "green" hydrogen works. I live in the north, the very north, like constantly above the hudson bay north. Insufficient electrical infrastructure where gas infra exists isn't really a big niche anyway.

Hydrogen already is needed today in some processes and some processes can only be made clean with clean hydrogen.

The hydrogen ladder offers a good overview of where hydrogen makes sense and where it doesn’t: https://www.linkedin.com/pulse/clean-hydrogen-ladder-v40-mic...

For me methane pyrolysis from biogas seems like the most realistic way of carbon capture (while also producing hydrogen).

Don't even think about carbon capture. Affording it any thought as a production process in the current world is "conservation of energy forbids it" level of impossible. Technology doesn't make it better either, it's just not feasible with the current energy output of the human race, not with (the very impressive) biogas pyrolysis nor with literal "air plastic".

Existing processes are the best use of hydrogen, and for those I'm fine with anything. It just makes little sense for energy applications.

The problem with carbon capture usually is extracting CO2 from the air and storing it without being emitted again.

Methane pyrolysis uses hardly more energy than steam reforming and leaves solid carbon as a side product. You don't need to concentrate carbon from the atmosphere, that was already done, solid carbon can be stored way more easily than the gas CO2. It has a very limited scale though, as you want to only use waste products for biogas production.

While I agree that hydrogen for electricity generation/storage doesn't really make sense, there are some industries that either can use or must use large amounts of hydrogen for chemical purposes. For example, the production of ammonia for fertiliser needs hydrogen, and refining metals from ore can use hydrogen.

That's obviously necessary, yes. It still really doesn't make much sense to do it with microbes when compared with SMR, though. It's entirely possible to store the CO from SMR as with microbes producing CO₂, but there's more CO₂ compared to CO from SMR.

Proton Technologies (mentioned in the article) claims to solve the problem by using a membrane that only lets hydrogen pass through. That way all the co2 just stays in the well. If that works that sounds way superior to SMR plus carbon capture.

Not really? It's not different from SMR. Hydrogen is tiny and non-polar, so it's easy to filter only for such small molecules, making storing it a pretty big issue. SMR produces a mixture of methane, water, hydrogen and carbon monoxide, which is just as easily filtered into plain dihydrogen. Nevertheless, it's still just storing it somewhere in a cave, not really worth the effort most of the time, and since CO / CO₂ is a lot smaller than methane, it'll find its way out by other means way easier.

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