Cleaning the atmosphere of CO2 just got possible

[free spirit]

Fussing at the margins, free spirit.

It doesn't work:

bollocks, nobody has actually funded a fully commercial scale project to fully test it at commercial scale, but eggborough have been operating a fully working 5MW pilot CCS add on to their plant for several years and that works (I know one of the control room engineers there).

This is the same crap that led to the UK abandoning fluidised bed coal plants in the 80s after british coal financed the first prototype due to some teething problems. The technology developed at UK tax payers expense by UK universities (well, mainly my dads research team at Leeds) and British Coal is now used successfully in hundreds of efficient clean burning coal plants around the world, but not in a single UK plant, and the UK gained pretty much zilch from developing the technology as the companies involved were bought up by foreign companies after the UK cancelled their plans to build any further plants after the trial plant.

It will never make any material impact:

of course it could, we could replace a significant number of existing coal plants with it within a generation, but we're back to your bollocks about nothing being worthwhile unless it can provide all the world's energy requirements by itself aren't we.

Its exacting storage requirements are unachievable:

This is being piped back into the depleted north sea gas fields, and I'd think you'd have to agree there is a fairly significant volume down there that could either be filled with CO2 before the infrastructure rusts away, or they could be sealed and the opportunity lost.

And it pollutes water aquifers:

it's filling up old gas fields offshore, so no it won't, or any it might do would already have been polluted by 40 years of gas extraction if this was the case.

etc. etc.

I don't believe so - I don't think the original study accounted for normalised constant nominal output i.e. CCS is assumed to be powered by the facility, and facility output derated accordingly. It doesn't really alter the point that the fuel supply must increase significantly, in the context that high grade coal stocks are depleting and the energy costs of mining lower grade coal is rising exponentially and, with it, the unaccounted for CO2 associated with securing the power station's fuel supply.

it did, at least the percentage figures you're quoting definitely are at the top end of the actual reduction in net thermal efficiency, and 15-20% is a hell of a lot different to 66%, so yes it alters the point significantly.

 

[Falcon]

bollocks, nobody has actually funded a fully commercial scale project to fully test it at commercial scale

The scale fallacy is debilitating, here. "It works for a short period in the lab under ideal conditions, so of course it will work at 1,000 times the scale under conditions that are statistically guaranteed to be worse in every relevant dimension for the life of a commercial project". Isn't the point of a pilot to evaluate the probability of success of a commercial project, and isn't the absence of commercial projects both entirely rational given the low rate of success of the pilots, and evidence of the failure of the pilots?

of course it could, we could replace a significant number of existing coal plants with it within a generation

You missed out the crucial word: "if".

A leakage rate of only 1% results in 75% storage loss in 140 years i.e. no material storage in any timescale relevant to the climate you seek to protect. The number of power plants that sit on structures that won't communicate with the surface through leak paths undetectable prior to pressurisation and activated by the pressurisation process is vanishingly small. We can't replace a significant number of plants. Scale fallacy again.

This is being piped back into the depleted north sea gas fields, and I'd think you'd have to agree there is a fairly significant volume down there that could either be filled with CO2 before the infrastructure rusts away, or they could be sealed and the opportunity lost.

The latest McKinsey forecast shows that, at 10% per annum cost inflation and 10% depletion, the operational cost of lifting a barrel of North Sea oil will equal the oil price in seven years time. All that infrastructure is shutting down and, to try and delay that, maintenance is being cut. But pressurised CO2 causes pipeline embrittlement via mechanisms that still aren't well understood, increasing maintenance costs. And that was UK CCS's best disposal option - that's why it was chosen. All other options are worse than this, and this one sucks.

 

[WouldBe]

A leakage rate of only 1% results in 75% storage loss in 140 years i.e. no material storage in any timescale relevant to the climate you seek to protect. The number of power plants that sit on structures that won't communicate with the surface through leak paths undetectable prior to pressurisation and activated by the pressurisation process is vanishingly small. We can't replace a significant number of plants. Scale fallacy again.

If there was a 1% leakage rate resulting in a 75% loss over 140 years we wouldn't have been able to extract natural gas from these wells as it would have all leaked out millennia ago.

 

[Falcon]

If there was a 1% leakage rate resulting in a 75% loss over 140 years we wouldn't have been able to extract natural gas from these wells as it would have all leaked out millennia ago.

The CCS reservoir needs four of the five structural features that oil and gas reservoirs need:

[1] a large volume of porous rock, in which the pores are connected over the entire extent of the volume i.e. permeable
[2] for that body to be deformed in such a particular way that the gas is trapped by density different with the aquifer, rather than able to migrate laterally
[3] for that porous, deformed containing structure to be overlaid by a sealing structure in which the pores are not connected, to prevent loss and
[4] for that sealing structure not to be penetrated by fractures.

(It doesn't require the fifth component - a hydrocarbon source)

All four elements must be present, and the absence of any one element prevents the formation of a stable reservoir. [4] is particularly arduous - gas is highly mobile, the entire structure can be evacuated through a single crack, the surface of the earth is very highly fractured, and the act of pressurising the reservoir creates fractures, or opens existing fractures.

The combination is very rare. 99% of all hydrocarbon that has ever formed has escaped due to the failure of one or more structural features.

The wells you cite are there because they have survived. The power facilities you wish to capture CO2 from are not collocated with these wells outside of an insignificant population of pilot studies. The probability of a structure conforming to the 4 structural elements being found under the location where the power facilities are located is vanishingly small.

 

[free spirit]

The scale fallacy is debilitating, here. "It works for a short period in the lab under ideal conditions, so of course it will work at 1,000 times the scale under conditions that are statistically guaranteed to be worse in every relevant dimension for the life of a commercial project". Isn't the point of a pilot to evaluate the probability of success of a commercial project, and isn't the absence of commercial projects both entirely rational given the low rate of success of the pilots, and evidence of the failure of the pilots?

what low rate of success?

Have you got examples of pilot plants that have been built and failed to work?

AFAIK the pilots work, the technology is scalable, it just needs a lot of investment to build an entirely new plant and all the associated infrastructure to pipe the CO2 offshore, and in this political climate of austerity.

PS your idea of laboratory conditions is obviously a bit different to mine...

This is a unit bolted to the side of the smokestack of a working MW scale coal fire power station at Ferrybridge we're talking about here, not a university lab.

You missed out the crucial word: "if".

A leakage rate of only 1% results in 75% storage loss in 140 years i.e. no storage at all in any timescale relevant to the climate you seek to protect. The number of power plants that sit on structures that won't communicate with the surface through leak paths undetectable prior to pressurisation and activated by the pressurisation process is vanishingly small. We can't replace a significant number of plants. Scale fallacy again.

any gas fields with that sort of leakage rate wouldn't have contained any gas in the first place.

The latest McKinsey forecast shows that, at 10% per annum cost inflation and 10% depletion, the operational cost of lifting a barrel of North Sea oil will equal the oil price in seven years time. All that infrastructure is shutting down and, to try and delay that, maintenance is being cut. But pressurised CO2 causes pipeline embrittlement via mechanisms that still aren't well understood, increasing maintenance costs. And that was UK CCS's best disposal option - that's why it was chosen. All other options are worse than this, and this one sucks.

I'll leave the materials scientists and engineers to sort that one out if it is an issue

 

[free spirit]

The wells you cite are there because they have survived. The power facilities you wish to capture CO2 from are not collocated with these wells outside of an insignificant population of pilot studies. The probability of a structure conforming to the 4 structural elements being found under the location where the power facilities are located is vanishingly small.

Why do you think that MegaWatt valley is referred to as MegaWatt valley?

within a few miles of each other there is drax, eggborough and ferry bridge with a combined generation capacity of 8GW, so with grid connection capacity for that level of power generation, as well as rail, canal and road links for importing coal (or biomass) from the nearby North Sea ports, as well as what remains of the local coal fields.

This is what is being proposed (following the pilot project) to be connected up via a single pipeline to the depleting north sea gas fields to then pump CO2 into the north sea.

Now maybe a 85-90% reduction in CO2 emissions from 8 GW of our carbon intensive baseload coal fired power stations doesn't rate as being significant in your rather odd world view, but to the rest of the energy industry that rates as pretty much the biggest single step we could take in the next few years to make a dramatic step change in our carbon emissions.

Add in a percentage of biomass to the mix and the entire lot could potentially become carbon negative / or more likely part of it will switch to biomass, part to CCS.

Yes this may only be a temporary stop gap solution for the next few decades, but it's a much needed stop gap solution, and one that could revolutionise the low carbon energy picture for the crucial period between now and 2050 or so before thorium, renewables etc can really ramp up to fill that gap.

 

[WouldBe]

The wells you cite are there because they have survived. The power facilities you wish to capture CO2 from are not collocated with these wells outside of an insignificant population of pilot studies. The probability of a structure conforming to the 4 structural elements being found under the location where the power facilities are located is vanishingly small.

Drax power station is to build a pipeline to link the power station with gas wells in the north sea. If these gas wells have held methane in for millennia, under pressure, without fractures forming they should also be able to hold CO2.

 

[equationgirl]

Falcon

Saying a technology is not proven commercially is absolutely not the same at saying it doesn't work. Most, if not all, technologies are proven a small scale first and require a lot of development to get them to MW size, let alone power plant size.

Furthermore, lots of power plants around the world don't use high grade coals, simply because they are not available locally or are exported because it makes economic sense to do so.Low grade coal use if becoming more and more popular, especially with the use of circulating fluidised bed plants which can burn low grade coals quite easily.

I agree that there are problems with underground CO2 storage so I think it's more likely that more plants will turn CO2 into useful precursors such as those required for the cement industry.

 

[WouldBe]

I agree that there are problems with underground CO2 storage so I think it's more likely that more plants will turn CO2 into useful precursors such as those required for the cement industry.

What precursors are those?

 

[equationgirl]

What precursors are those?

Cement precursors. I posted about them earlier in the thread.

 

[free spirit]

What precursors are those?

limestone essentially.

 

[gentlegreen]

But what would have an appetite to make carbonates other than pure metals ?

 

[free spirit]

But what would have an appetite to make carbonates other than pure metals ?

2 CaO + 3 Co2 = 2 CaCo3 + O2

lime + CO2 makes calcium carbonate or limestone.

EG will know more than me, but I think this was the process being used at Ferrybridge.

 

[gentlegreen]

But lime is made by cooking calcium carbonate to drive off CO2 !

 

[gentlegreen]

I just googled and apparently they use ammonia, but surely the Haber process is already a significant user of energy ?

 

[free spirit]

But lime is made by cooking calcium carbonate to drive off CO2 !

valid point.

On further investigation, it looks like the limestone is used in a reversible process to extract pure CO2 from the exhaust gasses for disposal, and it's just the spent lime after a certain number of cycles that is then sent for use as cement etc.

link 1
Link 2

Though EG may have been referring to a different process, I've only got a passing interest in this field.

 

[equationgirl]

I can't remember off the top of my head the exact process but the use of CO2 in useful industrial precursors is very much a hot topic at the moment.

http://www.unido.org/fileadmin/user...y_Efficiency/CCS/CCS_Industry_Roadmap_WEB.pdf

 

[WouldBe]

2 CaO + 3 Co2 = 2 CaCo3 + O2

lime + CO2 makes calcium carbonate or limestone.

EG will know more than me, but I think this was the process being used at Ferrybridge.

That would work but the CaO is obtained by roasting CaCO3 which gives off CO2 in the process.

 

[gentlegreen]

It all sounds a bit like "free energy" to me.

 

[WouldBe]

valid point.

On further investigation, it looks like the limestone is used in a reversible process to extract pure CO2 from the exhaust gasses for disposal, and it's just the spent lime after a certain number of cycles that is then sent for use as cement etc.

link 1

That idea is completely bonkers.

You burn coal in a power station which produces CO2. Then to get rid of it you burn more coal and 4 lots of propane which produces even more CO2. Meanwhile the CaO will only absorb the 1 lot of CO2 produced initially.

 

[WouldBe]

Whichever nutjobs came up with this idea should be sacked and have their degrees withdrawn. This is basic 3rd year (13/14 year old) science.

 

[free spirit]

That idea is completely bonkers.

You burn coal in a power station which produces CO2. Then to get rid of it you burn more coal and 4 lots of propane which produces even more CO2. Meanwhile the CaO will only absorb the 1 lot of CO2 produced initially.

I'm fairly sure that's just not explained well in the diagram / report, and either the propane is there to supply heating, or as a substitute for the coal, neither of which should be needed in a power station, or not needed much anyway if a little additional heating is needed.

I can't see how the propane is actually needed for the reaction itself.

I might be wrong, but the overall efficiency figures for the process are supposed to be good, which is why it's being considered as the best means of extracting / concentrating the CO2.

 

[equationgirl]

Don't know where the propane comes in (unless it's something to do with the burner ignition system), I don't recall it being part of any system I looked at.

 

[free spirit]

Don't know where the propane comes in (unless it's something to do with the burner ignition system), I don't recall it being part of any system I looked at.

I'm assuming it's used to supply heat in that small test system or something. I also assume that on the power station scale systems there'd be sufficient waste heat around to make that requirement redundant.

But yes it's a bit confusing, I'd not actually noticed that diagram when I posted the link up.

 

[Falcon]

Saying a technology is not proven commercially is absolutely not the same at saying it doesn't work.

I'm saying it's *also* not proven commercially.

 

[Falcon]

This is what is being proposed (following the pilot project) to be connected up via a single pipeline to the depleting north sea gas fields to then pump CO2 into the north sea.

The cost of operating those fields will exceed the oil price in seven years time and they will close. It is irrelevant whether you agree with a forecast based on the two decade cost inflation trajectory. It is beyond dispute that they will close within the assumed economic life of the CCS investment.

At that point, the full cost of operating the disposal infrastructure (and a share of the $billion abandonment capital expenditure provision) - still inflating at 10% compound annual growth rate i.e. doubling every seven years - will then transfer to the CCS project. The CCS project has not factored the full cost of operating the disposal infrastructure into project economics.

What is being proposed is not consistent with north sea economics.

Meanwhile, there is no substitute disposal facility.

 

[WouldBe]

I'm assuming it's used to supply heat in that small test system or something. I also assume that on the power station scale systems there'd be sufficient waste heat around to make that requirement redundant.

I'm sure I read some where in that link that the flue gasses needed to be cooled before feeding into the CO2 extraction unit. The diagram then shows the gasses being heated by a pre-heater and then propane being used to heat it further (propane is not needed chemically for those processes only needed to provide the heat required). This releases more CO2 and NOx that then need to be captured and dealt with.

Not sure what the flue gas temp of a power station is but it might be possible / more economical to use the heat from the flue gasses to drive the CaCO3 to CaO process first then the cooled gasses can then be fed straight into CaO to CaCO3 process cutting out most if not all of the extra heating required and reducing the amount of CO2 produced in the running of the unit.

1 of the diagrams shows the 'captured' CO2 being released up a chimney.

The article states that by supplying the cement industry with CaO it would reduce the amount of energy the cement works would need to use. While this is true you still need to use the same amount of energy at the power station to convert the CaCO3 to CaO that you would at the cement works so all you are doing is moving the energy use from 1 location to another.

 

[free spirit]

After a bit more digging, I'm a lot less keen on this Drax CCS scheme, as they now seem to be planning to use deep sea saline aquifers for storage, and I'm a lot less keen on that concept.

I'm sure in the original plans drawn up by Yorkshire Forward, before the government scrapped the regional development agencies, the plan was to build a pipeline to connect up with one or more of the big almost depleted gas fields.

Looks like they either missed the boat, or had to go for the cut price option.

I really don't think we understand the deep ocean well enough to be sticking huge amounts of CO2 down there and expecting that it's definitely going to stay down there, and not have any other negative impacts.

 

[WouldBe]

After giving this idea some more thought it may work provided you use a surplus of CaO.

Previous ideas about reducing the amount of extra energy needed to run the process would still apply.

If may be possible to use a sterling engine utilising surplus heat in the flue gasses to run a compressor to compress the concentrated CO2.

 

[gentlegreen]

Seems logical to combine the power station with the cement-equivalent factory - or at least part of it if that's a way to use waste heat / gases.
Do they make gypsum from SOx anywhere ?