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Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

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Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#71
post #67

I thought it was a really captivating and well written article. News on hydrogen often seems to swing between too expensive to produce and its the future. Out of the blue, news in the UK this week says hydrogen will be added to the natural gas supply from 2025.

I mean it's the second most abundant element in the universe.

Isn't it mostly in stars?

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#72
post #58

Earlier quoted context omitted.

While it would still be an upgrade over fossils, I think that would be a slap in the face for renewables. We need sustainable energy production, not more digging for stuff that is limited by design.

In principle, hydrogen is produced underground when iron (II) silicate reacts with water: 2 FeSiO3 + H2O >> H2 + Fe2O3 + SiO2 As I understand it, this is a "low-pressure" reaction. The FeSiO3 regeneration happens when iron (III) oxide sinks deep into the crust and reacts with silicates, releasing oxygen. I'm not clear on the specifics, but the ultimate energy source is (necessarily) plate tectonics, driven by the dec…

I think it’s renewable in a somewhat weaker sense: there is a lot of iron (II) (and perhaps other minerals that can also reduce water) in the crust, and there is a lot of water, and water percolates and finds these minerals at a rate that may produce hydrogen continuously at a sufficient rate for humanity.

More strongly, even if plate tectonics were needed, it doesn’t necessarily take anywhere near 1 TW of power to move enough material to produce 1 TW worth of useful stuff. The energy in question here is chemical, not kinetic.

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#73
post #38

Earlier quoted context omitted.

But then we burn all that hydrogen and use up all our oxygen. CO2 may be a greenhouse gas, but plants pull the oxygen back off and return it to the air.

Plants aren't doing that job all that effectively, or the CO2 levels wouldn't be going up. The entire history of industrial civilization has added 140 parts per million of CO2 to the atmosphere. For CO2, that's too much. But Oxygen is 21% of the atmosphere, or 210,000 parts per million. I think we'll be ok for a while.

>> Plants aren't doing that job all that effectively, or the CO2 levels wouldn't be going up.

Sure, but they DO reduce the level over time and they also grow faster with the higher concentration. The CO increase is less than all the CO2 we've produced with industry.

It's not ok to say there is 21 percent oxygen and this proposed process won't put a dent in it. One might have thought that about burning hydrocarbons. The question of how long can we "burn rocks" still stands. Is it 10k years or 10M or something else?

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#74

Earlier quoted context omitted.

this is like saying that the knife industry is setup for murders. your statement completely ignores the rapidly developing green hydrogen industry. Those are TODAY sources. just because there are large number of non-clean doesn't mean the clean ones dont exist.

Green hydrogen is not a fuel source. It takes more energy to create green hydrogen than it provides as a fuel, so green hydrogen is a energy transport mechanism, not a source.

If bursty, uneven sources of energy like wind and solar can be used to produced hydrogen via electrolysis, it could still be a win for reducing carbon emissions even though more energy was used to separate the water than can be achieved by burning the resulting hydrogen. It is a way to store the energy, admittedly at a loss, from wind and solar.

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#75
post #34

Earlier quoted context omitted.

That has very little to do with the article, which is about actual hydrogen retrievable from underground deposits. It wouldn't be made from anything, just piped out of the ground.

While it would still be an upgrade over fossils, I think that would be a slap in the face for renewables. We need sustainable energy production, not more digging for stuff that is limited by design.

Well then, why don't we stop digging for lithium for the batteries, rare earth minerals for all electronics, metals etc.

Where do you think the resources for renewable energy come from? Windmills and solar panels don't come out of thin air.

"No more digging stuff" shows such a disconnected view from reality. Everything is "limited" in some sense. The puritan attitude as if you can somehow avoid using resources, is just wrong. And oil is hardly the most scarce resource that's at the biggest risk of running out right now.

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#76
Here's an interesting talk about some of the reactions that are hypothesized to occur (albeit here in an extraterrestrial context). The speaker indicates that temperatures would need to be around 300C for these reactions to occur at an appreciable rate. Maybe that is found, deep enough in the Earth?

https://www.youtube.com/watch?v=df8L0khbrts

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#77

Earlier quoted context omitted.

While it would still be an upgrade over fossils, I think that would be a slap in the face for renewables. We need sustainable energy production, not more digging for stuff that is limited by design.

"Critically, natural hydrogen may be not only clean, but also renewable. It takes millions of years for buried and compressed organic deposits to turn into oil and gas. By contrast, natural hydrogen is always being made afresh, when underground water reacts with iron minerals at elevated temperatures and pressures."

The idea that oil and gas come from decaying organic matter is the prevailing theory in the west but some people including Thomas Gold had the idea that they come from the primordial material the earth is made of, and seep up to the crust.

If that is the case then there could be vast quantities of hydrocarbons inside the earth.

https://youtu.be/lr42BP3wvOw

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#78

Why this is interesting, we already have such a fuel, we found it 80 years ago and its called Thorium. And Uranium isn't bad either. And we don't have to find it, every rare earth mine thorws out absurd amounts of it. We have to much of it without even trying. We just to dumb and lazy to anything with it.

Thorium is most abundant in India. It’s obvious why the United States will not want to push a technology that will benefit others and that it cannot dominate.

Sure there’s seawater…but that is even more difficult to control.

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#79
post #12

So maybe there's a lot, maybe there's not. One quote from the article, though, is so typical: “We have the concept, we have the tools, the geology. … We only need people able to invest.”

Another quote from the same article:

"There might be enough natural hydrogen to meet burgeoning global demand for thousands of years, according to a U.S. Geological Survey (USGS) model that was presented in October 2022 at a meeting of the Geological Society of America."

Re: Hydrogen: Does Earth hold vast stores of a renewable, carbon-free fuel?

#80
post #52

> A second mechanism, radiolysis, may generate the rest. As radioactive elements in the crust such as uranium and thorium decay, they emit beta particles, aka helium nuclei, What is this? Chat-GPT writing "sciency" fairytales?

Off-by-one errors are notoriously difficult to avoid, after all ;)
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