Cleaning the atmosphere of CO2 just got possible

[8ball]

If only there was some way to sunlight directly into electricity.

... and store and distribute it efficiently the whole bottle...

 

[xenon]

If you can bootstrap the process by using energy from non fossel sources, to build the equipment. Then have these things solar powered and sat in a desert. What's the problem? Well apart from all the engineering problems in getting to that stage. But sure, plant more trees where you can. If machines can supplement natural CO2 sequestering I think we should use them too.

 

[xenon]

... and store and distribute it efficiently the whole bottle...

I believe that's called coal. Admittedly there's quite a gap between the sunlight in and portable energy store stages.

 

[WouldBe]

If capturing CO2 at source didn't take an obscene amount of energy, we could burn fossils cleanly and there wouldn't be any global warming to worry about. This scheme is a non-starter. As I said up there ^^^ it's the modern equivalent of perpetual motion. IT WILL NOT WORK!!!

Pumping CO2 into underground stores won't use obscene amounts of energy.

If you used a catalyst to convert the CO2 into something useful / less harmful to the environment then the catalyst could use the waste heat that also goes up the chimney to activate the catalyst. This uses no additional energy.

 

[WouldBe]

The first problem is that you cannot grow plants in the desert, which is where the best sunlight is. The second problem is that plants do not produce octane.

1. There might be lots of sunshine but there's not much CO2 in the desert.

2. Plants don't need to produce octane directly. Veg oil can be used as a diesel replacement and you can catalytic crack it to produce octane.

 

[WouldBe]

I believe that's called coal. Admittedly there's quite a gap between the sunlight in and portable energy store stages.

We already have portable electricity stores called batteries.

 

[Quartz]

1. There might be lots of sunshine but there's not much CO2 in the desert.

There's as much CO2 in the desert as there is elsewhere in the world. The atmosphere mixes it pretty thoroughly.

 

[WouldBe]

There's as much CO2 in the desert as there is elsewhere in the world. The atmosphere mixes it pretty thoroughly.

Yes but far less than at the top of a powerstation chimney.

 

[Bob_the_lost]

Pumping CO2 into underground stores won't use obscene amounts of energy.

If you used a catalyst to convert the CO2 into something useful / less harmful to the environment then the catalyst could use the waste heat that also goes up the chimney to activate the catalyst. This uses no additional energy.

And yet no one wants to touch it with a barge pole.

 

[WouldBe]

And yet no one wants to touch it with a barge pole.

They probably can't see a profit in it or can't see how to add being a fuel provider to their business model.

Perhaps like solar companies can rent roof space maybe some start up company could rent 'chimney space'.

 

[MikeMcc]

Pumping CO2 into underground stores won't use obscene amounts of energy.

If you used a catalyst to convert the CO2 into something useful / less harmful to the environment then the catalyst could use the waste heat that also goes up the chimney to activate the catalyst. This uses no additional energy.

With present technology it does unfortunately, CCS would reduce a fossil fuelled power stations efficiency by 25 - 40% depending on the technology used. But this doesn't taking in to account expenses that aren't built into the present energy production use (i.e. loss of income from people invalided from exposure to the pollutants involved and their care costs). There are promising methods coming along, but we are a long, long way from realistic, economic CCS given the present pricing structures.

 

[WouldBe]

With present technology it does unfortunately, CCS would reduce a fossil fuelled power stations efficiency by 25 - 40% depending on the technology used. But this doesn't taking in to account expenses that aren't built into the present energy production use (i.e. loss of income from people invalided from exposure to the pollutants involved and their care costs). There are promising methods coming along, but we are a long, long way from realistic, economic CCS given the present pricing structures.

Yet it was on the news only the other day that Drax power station is going ahead with carbon capture.

 

[WouldBe]

There's as much CO2 in the desert as there is elsewhere in the world. The atmosphere mixes it pretty thoroughly.

When was the last time you saw smog in the desert?

 

[Quartz]

When was the last time you saw smog in the desert?

IIRC smog is usually caused by particulates and sulphur compounds, not CO2.

 

[WouldBe]

IIRC smog is usually caused by particulates and sulphur compounds, not CO2.

Thought you might say that. Also the brown colour is caused by NOx.

Unfortunately these aren't produced independently. They are all the result of combustion which will naturally produce CO2 as well so the atmosphere doesn't mix things that well.

OK CO2 is a problem globally but the other shit you mention causes serious health problems locally. So I still say it's better to deal with the problem at source rather than in the middle of the desert even if there is more sunshine there.

 

[WouldBe]

... and store and distribute it efficiently the whole bottle...

If we had enough green power we could uses places like Dinorwick(sp) in reverse. Use excess solar power in the day to pump water to the top and then release it at night when the suns gone down.

 

[Quartz]

OK CO2 is a problem globally but the other shit you mention causes serious health problems locally. So I still say it's better to deal with the problem at source rather than in the middle of the desert even if there is more sunshine there.

I'd prefer the pollutants weren't emitted in the first place. But deserts are where the reliable sunlight is. And specifically you're looking for deserts by the sea, for water, so you want places like Namibia, Libya, southern Morocco and Mauretania, the borders of the Red Sea, southern Australia (the Nullarbor plain), and the Atacama desert in Chile. And if you remove CO2 there, it will get removed by dilution thanks to atmospheric mixing from other places.

 

[MikeMcc]

Aye, but it is still a good idea. The process won't be improved until we try it on industrial scales. We still don't know what happens when we inject that much CO2 into the rock strata yet, though it's unlikely to be as bad as just letting it into the atmosphere.

 

[WouldBe]

I'd prefer the pollutants weren't emitted in the first place.

I agree which is why it's better to do it at source.

 

[WouldBe]

Anyway if this device just uses electricity to operate it then why not build a solar farm in the desert and have the units in the cities?

 

[Bob_the_lost]

Anyway if this device just uses electricity to operate it then why not build a solar farm in the desert and have the units in the cities?

Because there are energy losses transmitting power that far and this is entirely built around the concept of making the most efficient use of energy.

 

[WouldBe]

Because there are energy losses transmitting power that far and this is entirely built around the concept of making the most efficient use of energy.

Well stick a few more solar panels in then to make up for the transmission losses. You wouldn't be actually transmitting the power that far anyway. You would be using power generated locally and offsetting it with the power generated in the desert.

You also have to take account of the extra CO2 emitted during the long trips out to the desert to collect the formic acid or whatever else you use these devices to make.

 

[equationgirl]

Yet it was on the news only the other day that Drax power station is going ahead with carbon capture.

No, Drax is going ahead with a converting a second unit to biomass after successfully winning a legal challenge against the government.
http://www.theguardian.com/business.../14/drax-high-court-ruling-government-subsidy

Carbon capture is a completely different technology, although sometimes biomass is lumped in the same category.

 

[WouldBe]

http://www.bbc.co.uk/news/uk-england-york-north-yorkshire-28207963

Says they have got funding to go ahead with carbon capture.

 

[free spirit]

No, Drax is going ahead with a converting a second unit to biomass after successfully winning a legal challenge against the government.
http://www.theguardian.com/business.../14/drax-high-court-ruling-government-subsidy

Carbon capture is a completely different technology, although sometimes biomass is lumped in the same category.

they've also got funding from europe to build a carbon capture plant.

 

[Falcon]

they've also got funding from europe to build a carbon capture plant.

The energy calculations are hilarious.

Capturing and compressing CO2 is extraordinarily energy intensive. IPCC estimates that it may increase the fuel needs of a coal-fired CCS plant by 25–40% to drive the processes [1].

Assuming fixed nominal power output, that means its capacity must be increased by that amount to power carbon capture. But that additional capacity will generate CO2, for which additional capacity must be installed. Which will generate CO2, for which etc. That calculation is asymptotic after about 5 levels of recursion.

So taking Longannet power station near me. Nominal output is 2.4GW, consuming 4.5 million tonnes of coal a year and generating 1.6 million tonnes a year of toxic fly ash [2].

Carbon capture requires between 33% and 66% more coal (1.5 million - 3.0 million tonnes) per year, generating 0.5 - 1.0 million tonnes per year of additional toxic fly ash.

And no-one is sequestering (or accounting for) the CO2 emitted in the mining, processing, transportation, and waste disposal of that additional fuel.


[1] IPCC special report on Carbon Dioxide Capture and Storage. Prepared by working group III of the Intergovernmental Panel on Climate Change. (ref PDF)
[2] Engineering Timelines - Longannet Power Station (ref)

 

[WouldBe]

why would we need so much formic acid?

If we need lots of formic acid can't we milk ants?

 

[free spirit]

The energy calculations are hilarious.

Capturing and compressing CO2 is extraordinarily energy intensive. IPCC estimates that it may increase the fuel needs of a coal-fired CCS plant by 25–40% to drive the processes [1].

Assuming fixed nominal power output, that means its capacity must be increased by that amount to power carbon capture. But that additional capacity will generate CO2, for which additional capacity must be installed. Which will generate CO2, for which etc. That calculation is asymptotic after about 5 levels of recursion.

So taking Longannet power station near me. Nominal output is 2.4GW, consuming 4.5 million tonnes of coal a year and generating 1.6 million tonnes a year of toxic fly ash [2].

Carbon capture requires between 33% and 66% more coal (1.5 million - 3.0 million tonnes) per year, generating 0.5 - 1.0 million tonnes per year of additional toxic fly ash.

And no-one is sequestering (or accounting for) the CO2 emitted in the mining, processing, transportation, and waste disposal of that additional fuel.


[1] IPCC special report on Carbon Dioxide Capture and Storage. Prepared by working group III of the Intergovernmental Panel on Climate Change. (ref PDF)
[2] Engineering Timelines - Longannet Power Station (ref)

10 year old data Falcon. The Drax plant is using oxy-combustion, ie air with the nitrogen mostly removed prior to combustion to prevent / reduce the need to separate out the gases after combustion. According to this paper, that would give a 20% reduction in efficiency, so 31.5% instead of 39%, but also claims that introducing 3 other techniques could eventually raise this as high as 41.4%.

In reality these plant are mostly going to be replacing old ~37% efficiency plant anyway, so the reduction in efficiency is more like 15% old for new, and the pollution levels will be vastly reduced as the nitrogen is being removed at source, so it should have very little NOx emissions.

ps you've wrongly multiplied up your efficiency figures to get the 33% and 66% figures. The original figures already related to the thermal efficiency of the conversion, so it's a straight 20% more coal required vs a new none CCS plant, or 15% more than the old plant it is replacing, not 33-66% more coal for the same net electrical output.

 

[free spirit]

Not that there aren't downsides to it as you suggest, but I'd just prefer to deal with some more accurate numbers to give a more accurate impression of the magnitude of the additional coal, flyash etc we're talking about. 15% is a lot different to 66%, especially if it comes with a significant air pollution reduction at the same time.

 

[Falcon]

10 year old data Falcon.

Fussing at the margins, free spirit.

It doesn't work:

… the technology for capturing carbon has not been proved to work on a commercial scale, either in the United States or abroad. The Energy Department canceled its main project demonstrating the technology in 2008.
- "The Global Status of CCS" Global CCS Institute, 2013 (ref)

It will never make any material impact:

Sequestering a mere 1/10 of today’s global CO2 emissions (less than 3 Gt CO2) would thus call for putting in place an industry that would have to force underground every year the volume of compressed gas larger than or (with higher compression) equal to the volume of crude oil extracted globally by [the] petroleum industry whose infrastructures and capacities have been put in place over a century of development. Needless to say, such a technical feat could not be accomplished within a single generation.
- "Energy at the Crossroads", Smil 2005

Its exacting storage requirements are unachievable:

Even a very small leakage rate of well under 1% a year would render the storage system all but useless as a “permanent repository”
- "Carbon Capture And Storage: One Step Forward, One Step Back", Romm 2013

“One large, coal-fired plant generates the equivalent of 3 billion barrels of CO2over a 60-year lifetime. That would require a space the size of a major oil field to contain. The pressure could cause leaks or earthquakes.
- White (Director, US Energy Department’s carbon sequestration group)

And it pollutes water aquifers:

Leaks from carbon dioxide injected deep underground to help fight climate change could bubble up into drinking water aquifers near the surface, driving up levels of contaminants in the water tenfold or more in some places. ... Potentially dangerous uranium and barium increased throughout the entire experiment in some samples."
- Duke University (ref)

etc. etc.

ps you've wrongly multiplied up your efficiency figures to get the 33% and 66% figures. The original figures already related to the thermal efficiency of the conversion, so it's a straight 20% more coal required vs a new none CCS plant, or 15% more than the old plant it is replacing, not 33-66% more coal for the same net electrical output.

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.