Not quite true, 1/3 of energy may be from cars and household electricity but it doesn't mean the rest 2/3 are from industry. It's mainly from heating. And for heating there is a solution in form of heat pumps and energy-efficient buildings.
Cheap, green hydrogen would be a breakthrough in clean energy
151–160 of 254 posts
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#152Earlier quoted context omitted.
The problem with any fuel containing H2 in any existing engine is hydrogen embrittlement. Hydrogen is a reactive gas that attacks steel. Ammonia fuel cells have a comparable weight proposition to hydrogen at small sizes because the tank is so much lighter. I think that has legs (or wheels?). For stationary storage, the ammonia-CO2 adduct is a solid, which is nice.
Hydrogen embrittlement is always hyped to the sky. It is not a serious problem unless you are trying to keep warm, gaseous hydrogen under high pressure. So, don't. Furthermore, aluminum is quite resistant to embrittlement. Of possibly greater moment is that it leaks, and has ~200x GHG over CO2 (including secondary effects). Leaks are not dangerous in the open, or in confined places with positive airflow, but punishme…
> Of possibly greater moment is that it leaks
It leaks very readily, it ignites very readily, it burns with a wide range of air:fuel proportions, it burns with a high flame speed, and it burns hot.
Hydrogen is ... not a good choice for something to reticulate widely around the world.
Edit: That's leaving aside its low energy density. You need three times the volume of hydrogen as natural gas for the same quantity of heat, so existing pipe networks are unlikely to be useful.
Global warming potential is off to the side of all this.
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#153Earlier quoted context omitted.
It's not that capturing carbon and then releasing it again is good. What's good is that the liquid fuel (made from green energy plus captured carbon) can be used in existing cars, ships and aircraft. There's more info in the Wikipedia article I linked above. "In 2021, Audi announced that it was working on e-diesel and e-gasoline projects. "By 2021, the European Federation for Transport and Environment advised the avi…
Sorry, but I'm still not seeing how e-fuels are beneficial without violating the laws of thermodynamics. A plane is going to produce the same amount of CO2 whether kerosene or e-kerosene is used. The only way e-kerosene makes sense is if its production uses less CO2 than traditional oil extraction and refining. Given the relative simplicity of oil extraction, I find it hard to believe this will be the case. Maybe it…
> The only way e-kerosene makes sense is if its production uses less CO2 than traditional oil extraction and refining.
Yes -- hold that thought! As noted above, e-fuel is made from green energy and captured CO2. So, net zero, more or less, after the fuel is burned. But traditional oil extraction doesn't begin by capturing CO2. So, burning that fuel is carbon positive.
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#154I can get behind the round-trip inefficiencies if it gets terribly cheap, but I can't imagine how storage and transportation can ever be economical. We are trying to contain the most volatile substance in the universe. It needs incredible pressure just to be manageable and even then, it freaking diffuses within the steel walls themselves, leaking and making it brittle over time. It's not hard to imagine single proton…
Handling LH2 is really not so different from handling LNG, which we do in the millions of tons.
It’s very, very different:
−160 °C vs -250 °C and liquid density of 450 vs 70 kg/m3
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#155The FF industry is leaping (has leapt, historically) on CCS as a getout clause and has sunk french metric tonnes of money into CCS. So far, its uneconomic except for the specific use of pumping gas into wells to make them more productive, which leads to more fugitive gas. No significant CCS experiment worldwide has achieved its goals as sequestration. The one in Western Australia releases so much CO2 it has to pay a…
I fully agree with your perception of CCS but i think it's only a small historical detour of about the same scale/level of harm as cellulosic ethanol or concentrated solar thermal used to be. Tried, failed, moved on. No one bets the farm on it, Fit for 55 plan for example, makes no mention of CCS.
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#156Earlier quoted context omitted.
Sorry, but I'm still not seeing how e-fuels are beneficial without violating the laws of thermodynamics. A plane is going to produce the same amount of CO2 whether kerosene or e-kerosene is used. The only way e-kerosene makes sense is if its production uses less CO2 than traditional oil extraction and refining. Given the relative simplicity of oil extraction, I find it hard to believe this will be the case. Maybe it…
> The only way e-kerosene makes sense is if its production uses less CO2 than traditional oil extraction and refining. Yes -- hold that thought! As noted above, e-fuel is made from green energy and captured CO2. So, net zero, more or less, after the fuel is burned. But traditional oil extraction doesn't begin by capturing CO2. So, burning that fuel is carbon positive.
Yes, but you're not answering why it's better to convert the captured CO2 into e-fuel rather than sequester it directly. My point is that converting to e-fuel instead of direct sequestration only makes sense if you can produce e-fuel from carbon more efficiently than you can extract and refine oil.
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#157The FF industry is leaping (has leapt, historically) on CCS as a getout clause and has sunk french metric tonnes of money into CCS. So far, its uneconomic except for the specific use of pumping gas into wells to make them more productive, which leads to more fugitive gas. No significant CCS experiment worldwide has achieved its goals as sequestration. The one in Western Australia releases so much CO2 it has to pay a…
FF: fossil fuel. CCS: carbon capture and storage.
THANK YOU
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#158The FF industry is leaping (has leapt, historically) on CCS as a getout clause and has sunk french metric tonnes of money into CCS. So far, its uneconomic except for the specific use of pumping gas into wells to make them more productive, which leads to more fugitive gas. No significant CCS experiment worldwide has achieved its goals as sequestration. The one in Western Australia releases so much CO2 it has to pay a…
I fully agree with your perception of CCS but i think it's only a small historical detour of about the same scale/level of harm as cellulosic ethanol or concentrated solar thermal used to be. Tried, failed, moved on. No one bets the farm on it, Fit for 55 plan for example, makes no mention of CCS.
Not here in Australia.
Have a look at: https://www.kwm.com/au/en/insights/latest-thinking/ccs-in-au...
(Burrup is the one I mentioned)
Thats $250 million of committed funding to a range of high scale projects by the gas industry, coal-seam gas included.
Re: Cheap, green hydrogen would be a breakthrough in clean energy
#159Re: Cheap, green hydrogen would be a breakthrough in clean energy
#160It would. Yet there is no promising tech in this field. Hydrogen is supported only to draw support away from EVs. If hydrogen becomes inexpensive to produce, it will by by way of solar power used to generate it. It will never be easy to store. Hydrogen is the smallest element, and can move through solid objects over time. It is violently explosive. You think these EV fires you see all the time are bad? They're nothin…
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