The Death Of Fossil Fuels

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bjn
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Re: The Death Of Fossil Fuels

Post by bjn » Wed Jun 12, 2024 12:43 pm

Grumble wrote:
Wed Jun 12, 2024 11:26 am
shpalman wrote:
Wed Jun 12, 2024 11:19 am
But I don't think anyone would be suggesting building one huge machine to deal with the whole world's emissions. Why don't you try to figure out how many reasonably sized machines the UK would need?
I don’t think he was suggesting one big machine
I definitely wasn't. I was trying to put a bound on how big a problem it was from a simple infrastructure point of view. For the UK you'd need about 2km^2 of inlet for beuafort 4 air speeds. That is 4 million 1x1m inlets moving air at 24km/h all day and all night. Arrange those square meters as you see fit. You'd need more if you run at a lower airspeed.

They would all need to be clustered near to where ever you were dumping the carbon. I have a feeling this might kick up a fuss at serried walls of these things hundreds of meters long making noise all day and night.

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Re: The Death Of Fossil Fuels

Post by bjn » Wed Jun 12, 2024 1:03 pm

IvanV wrote:
Wed Jun 12, 2024 12:02 pm
The calculation in the Wired article only looks at the energetic cost of capturing the carbon from the air. Essentially that treats the sequestration as energetically free, which thermodynamically is true - the combination of wet basalt and CO2 is energetically favourable, just very slow. So far, there has been a lot of focus on carbon sequestration, but actually the carbon capture is the more difficult bit. People think about capturing carbon from vents of power stations, and think it must be straightforward to capture it all. But actually the processes tested so far capture quite disappointing proportions of it. You'd have to be capturing 90%+ of the CO2 from a methane power station to get something properly worthwhile, and I don't think anything near that has been demonstrated at scale.
If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/

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Re: The Death Of Fossil Fuels

Post by IvanV » Wed Jun 12, 2024 1:20 pm

bjn wrote:
Wed Jun 12, 2024 1:03 pm
If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/
That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.

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Re: The Death Of Fossil Fuels

Post by bjn » Wed Jun 12, 2024 1:38 pm

IvanV wrote:
Wed Jun 12, 2024 1:20 pm
bjn wrote:
Wed Jun 12, 2024 1:03 pm
If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/
That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.
On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.

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Re: The Death Of Fossil Fuels

Post by IvanV » Wed Jun 12, 2024 4:11 pm

bjn wrote:
Wed Jun 12, 2024 1:38 pm
IvanV wrote:
Wed Jun 12, 2024 1:20 pm
That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.
On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.
That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.

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Re: The Death Of Fossil Fuels

Post by bjn » Wed Jun 12, 2024 7:59 pm

bjn wrote:
Wed Jun 12, 2024 12:43 pm
Grumble wrote:
Wed Jun 12, 2024 11:26 am
shpalman wrote:
Wed Jun 12, 2024 11:19 am
But I don't think anyone would be suggesting building one huge machine to deal with the whole world's emissions. Why don't you try to figure out how many reasonably sized machines the UK would need?
I don’t think he was suggesting one big machine
I definitely wasn't. I was trying to put a bound on how big a problem it was from a simple infrastructure point of view. For the UK you'd need about 2km^2 of inlet for beuafort 4 air speeds. That is 4 million 1x1m inlets moving air at 24km/h all day and all night. Arrange those square meters as you see fit. You'd need more if you run at a lower airspeed.

They would all need to be clustered near to where ever you were dumping the carbon. I have a feeling this might kick up a fuss at serried walls of these things hundreds of meters long making noise all day and night.
That should of course read 2 million inlets of 1m^2, not 4 million. Sorry.

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Re: The Death Of Fossil Fuels

Post by IvanV » Fri Jul 05, 2024 1:47 pm

Chasing efficiency from domestic heat pumps (Wired)
Interesting article. A guy with a not-very-easy-to-insulate-well house, up a big hill near Sheffield, is nonetheless doing very well with his heat pump and getting a SCOP of about 5 from it. Other examples discussed.

It turns out there's quite a bit you can do to get down the cost of your heating, even if your house is hard to insulate thoroughly. Though, unsurprisingly, the most efficient systems are more expensive.

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Re: The Death Of Fossil Fuels

Post by Grumble » Wed Jul 10, 2024 8:51 am

So glad that Rachel Reeves has announced barriers to onshore wind will be removed. Takes time to get projects like that moving, but I’m hopeful that by the end of this government we’ll be in a much better place.
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Re: The Death Of Fossil Fuels

Post by Sciolus » Wed Jul 10, 2024 9:27 am

The critical barriers to onshore wind have already been removed, as of Monday. There is a bit more to do (which I think will require secondary legislation) to make the planning process more consistent with other major projects.

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Re: The Death Of Fossil Fuels

Post by Imrael » Wed Jul 10, 2024 9:57 am

IvanV wrote:
Wed Jun 12, 2024 4:11 pm
bjn wrote:
Wed Jun 12, 2024 1:38 pm
IvanV wrote:
Wed Jun 12, 2024 1:20 pm
That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.
On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.
That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.
Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.

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Re: The Death Of Fossil Fuels

Post by Grumble » Wed Jul 10, 2024 10:06 am

Imrael wrote:
Wed Jul 10, 2024 9:57 am
IvanV wrote:
Wed Jun 12, 2024 4:11 pm
bjn wrote:
Wed Jun 12, 2024 1:38 pm


On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.
That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.
Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.
I do think we need “all of the above” but CCS has the risk of being a fig leaf for carbon emitters. We should first concentrate on getting emissions down all the way.

Having said that, e-fuels are what you are talking about. Fossil fuel companies are looking into those
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Re: The Death Of Fossil Fuels

Post by Matatouille » Wed Jul 10, 2024 11:20 am

Imrael wrote:
Wed Jul 10, 2024 9:57 am
Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.
Already happening.

https://www.reuters.com/business/enviro ... 024-05-08/

IIRC they make carbonated water (water also plentiful in Iceland), and frack it into deep granite where the carbon reacts quickly to form a stable mineral. And Iceland has enough suitable rock to deposit humanity's carbon output at the current rate for a millennium or not. The rocks they need are apparently globally common, so if you could persuade a local area to accept fracking there is a good option for sequestration of direct captured carbon without transporting all the way to Iceland.

So yes if we do fall back on direct air capture, Iceland doesn't look like a bad place to do it.

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Re: The Death Of Fossil Fuels

Post by IvanV » Wed Jul 10, 2024 12:02 pm

Matatouille wrote:
Wed Jul 10, 2024 11:20 am
Imrael wrote:
Wed Jul 10, 2024 9:57 am
Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.
Already happening.

https://www.reuters.com/business/enviro ... 024-05-08/

IIRC they make carbonated water (water also plentiful in Iceland), and frack it into deep granite where the carbon reacts quickly to form a stable mineral. And Iceland has enough suitable rock to deposit humanity's carbon output at the current rate for a millennium or not. The rocks they need are apparently globally common, so if you could persuade a local area to accept fracking there is a good option for sequestration of direct captured carbon without transporting all the way to Iceland.

So yes if we do fall back on direct air capture, Iceland doesn't look like a bad place to do it.
I think carbon capture as a service is an excellent idea. You want to buy some carbon emitting fuel, because other choices are difficult? Well, you have to buy some carbon capture as a service with it. And someone would actually verifiably capture it, we are not in the dubious offsets market.

Yes, Iceland has been experimenting with capturing carbon in basalt. Because basalt will react with CO2 and hold it, and that's a thermodynamically feasible reaction that requires no energy input to make it happen, in a chemical/thermodynamic sense. It requires energy only to put the things in the right places, including drilling holes, fracking the rock, and maintain the pressure to try and make it happen at an appreciable speed. It's helpful that its really rather warm down there in Iceland. You say quickly, and it is quick in comparison to many natural carbon capture processes, but not quick by comparison to many processes in chemical processing plants. I think it takes some months for most of the CO2 they pump down to be sequestered. As it says there, the first trial plant had a capacity of 4,000 tonnes/yr. Now there's a new plant of 36,000 tonnes/year.

The UK emits around 5 tonnes per person per year, and I think Iceland rather more, for all their hydro and geothermal, because of all their aluminium processing. So these are really very small amounts. They hope to get up to million tonnes/yr by 2030, and gigatonne by 2050. And this is going to involve a lot of drilling holes in lots of places as gigatonnes of carbonates are formed in the earth's crust. But there are many gigatonnes of basalt there in Iceland. A cubic km of basalt weighs about 4 gigatonnes. So there is potential to make it really something in 25 years. To make it really really something we need to see similar developments in other places with a lot of warm basalt. And there is no shortage of warm basalt, it tends to be around places with warm crust.

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Re: The Death Of Fossil Fuels

Post by lpm » Wed Jul 10, 2024 12:49 pm

It'll be interesting to see how it works in the 2200 to 22000 time frame.

Iceland could become the thermostat. Dial CO2 up and down to stabilise temperatures, prevent ice ages. Will be exciting to watch how it develops.
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Re: The Death Of Fossil Fuels

Post by Grumble » Sun Jul 14, 2024 7:06 am

Ed Milliband getting off to a flyer with some easy wins - approving some big solar farms and promising to make it easier to fit home solar. Seems like he might make it compulsory to fit solar to new homes as well.
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