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Comment by unchocked | Hacker News Reader

Yet it's absolutely required for synthesizing hydrocarbons from CO2 so, there's that.

I mean, pick any fuel you want, their utility as stores of energy are all based on hydrogen content. So we're going to kick the fossil habit and still have fuel of _any_ sort, we're going to have to learn to produce and utilize hydrogen at scale.

Grey and blue hydrogen are transition fuels. They build a market for green hydrogen to fill. It's going to be a little messy along the way.

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Sure, but when people say "hydrogen fuel" they usually mean pure H2. Trouble is, those carbon atoms everyone's so keen to get rid of are damn useful, chemically speaking. I actually think there's a lot more mileage in synthesizing hydrocarbons from biowaste. There's nothing inherently wrong with burning hydrocarbons - the problem is that we're lazily digging historical supplies out of the ground, instead of keeping the carbon cycle closed.

Really, we should just put massive tax levies on fossil fuel extraction operations and call it a day. The market will sort the rest out.

> There's nothing inherently wrong with burning hydrocarbons

...if and when you burn them with pure oxygen like done in rockets. Mostly they're burnt using using atmospheric oxygen though, leading to the production of nitrogen oxides (NOx) which come with their own problems [1]. It is possible to reduce the emission of these gases [2] at the cost of increased complexity and cost.

[1] https://en.wikipedia.org/wiki/NOx#Health_and_environment_eff...

[2] https://en.wikipedia.org/wiki/NOx#Regulation_and_emission_co...

NOx (and PM) is a local, temporary consequence. Catalysts exist to remove NOx out of exhaust gasses. They are perfectly serviceable.

Carbon dioxide is a permanent, global issue, where no (large-scale) capturing/cleaning methods exist.

NOx removes itself out of the atmosphere through natural means, CO2 does not.

You can close the cycle, hence 'ignore' CO2 emissions since they cancel out, and deal with NOx using today's existing technology. Same thing for PM and sulfur.

Tell that to the Dutch authorities who are using NOx emissions to restrict industry and agriculture...

> NOx removes itself out of the atmosphere through natural means

...because of this [1], among others.

[1] https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_c...

CO2 is a greenhouse gas, and combustion of hydrocarbons emits it.

And creation of hydrocarbons consumes it, so it all evens out in the long run. The problem is that we're digging up deposits hundreds of millions of years old, so evening out over the long run means atmospheric CO2 goes back to what it was back then, which is much higher. But if you burn vegetable oil that you only grew this year, that doesn't emit any net CO2.

We don't need an alternative to petrochemicals for rare use cases we decide are worth the cost-benefit ratio. I expect there will be jerrycans of synthesized gasoline on the McKendree cylinders riding fusion engines to other stars. For the odd use case where you need a stable high density fuel with minimal weight-costs on the engine, and you can tolerate the atmospheric effects it will make sense to use it so we will.

Fossil fuel is hopefully going away, but we will have petroleum in the toolbox forever and we can still use it when it makes sense to.

> I mean, pick any fuel you want, their utility as stores of energy are all based on hydrogen content.

OK, I pick black coal. No hydrogen content. What do I win?

Actually it does have hydrogen...

https://en.wikipedia.org/wiki/Bituminous_coal >The carbon content of bituminous coal is around 45–86%;[1] the rest is composed of water, air, hydrogen, and sulfur, which have not been driven off from the macerals.

>Actually it does have hydrogen...

Shitty coals like lignite and bituminous coal do. The real chad coal, anthracite, is up to 98% carbon.[1]

[1]https://en.wikipedia.org/wiki/Anthracite

Using hydrogen as an ingredient is not at all the same as using it as a fuel.

Plus you don't need hydrogen molecules to synthesize hydrocarbons, and when people say hydrogen they mean molecules.

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