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Comment by masklinn | Hacker News Reader

> Wait, what is this article about? Unless there's been a major breakthrough recently (which the article doesn't seem to mention from quickly skimming through) hydrogen is impractically expensive to produce.

Actually it's super easy, barely an inconvenience.

As long as you produce it by cracking fossil fuels anyway, which is how >95% of hydrogen production currently works.

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That’s still quite expensive, you start off with a useful fuel and then spend more money turning that into hydrogen while losing energy.

In theory hitting ~60% energy efficiency on solar power could be cheaper than fossil fuels. But hydrogen is a long way from that benchmark.

You also need hydrogen to make the original useful fuel, that's where about half of the current usage goes. I wonder if oil conpanies could be regulated into self supplying all their own hydrogen needs from green hydrogen.

But what's the point to produce hydrogen from hydrocarbons? Hydrocarbons are already an energy-dense, stable fuel.

I think that it's solar and wind energy, peaky and unstable as it is, should be used to produce hydrogen. Then it could be used as is, or combined with heavy hydrocarbons to produce much lighter hydrocarbons like methane. Maybe it can be economically used to produce something useful from CO₂, from fuel to plastics.

Burning hydrocarbons emits CO2, which is already at high enough atmospheric levels to make us less smart, as well as particulate matter, which is directly affecting air quality and shortening our lifespans.

Burning hydrogen emits water.

I see an important area where hydrocarbons will not be displaced by batteries and hydrogen for decades: jet fuel.

Burning CH₄ produces much more water and less CO₂ than burning longer hydrocarbons. This works for ICE car engines, with tiny modifications, too. So it could still be a useful step in phasing out carbon-based fuels, until we have epic-scale batteries and likely more nuclear generation.

So you can access those sweet Government subsidies:

https://www.ispionline.it/en/pubblicazione/eus-hydrogen-stra...

> “'Hydrogen Europe' promotes the growth of green hydrogen production in the EU... €145bn in support between grants and subsidies."

Carbon capture is much easier at a single hydrogen refinery than at thousands of vehicles or buildings.

What happens to the carbon after the hydrogen is separated?

Could this be a useful form of carbon capture for fossil fuels? Hydrogen at least burns much more cleanly at the point of use.

It gets thrown in the bin. That is, if you've made the hydrogen by pyrolysing natural gas, using a process which separates the carbon as a solid:

https://spectra.mhi.com/achieving-net-zero-what-is-turquoise...

You might even be able to sell some of it, although i suspect there isn't a market for all the carbon you would produce.

Steel production needs more or less pure carbon, and lots of it.

Paint producers would like to talk with you—carbon black is one of the basic pigments.

There's a company looking into this turquoise hydrogen that said the method has previously been optimised for multiple outputs to make the most money, but if it works at the scale we need it to for decarbonisation, we'll be overrun with carbon as a byproduct, so it would be unwise to assume you could sell all of it for the price that you currently can get, as you'd completely swamp the market, that's why they focus on making the economics work for just the hydrogen alone and consider anything else a bonus.

I'm sure someone will come up with something more interesting to do with it than just dumping it though if it all works out.

That’s neat, but the most common method, steam reforming, produces CO2 gas as the byproduct. Much more difficult to store.

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