Just as long as we don't over-saturate it.
This is the possible result:
http://en.wikipedia.org/wiki/Limnic_eruption
New research has possibly given a boost to the idea of carbon capture, indicating that CO2 is sometimes held dissolved in underground water for millions of years. However, it is acknowledged that CO2 contained in subterranean water is prone to bubble out again, and often does so - famously at naturally-sparkling springs, for …
Are Werner Aeschbach-Hertig and Stuart Gilfillan talking about the same thing? Oil and gas reservoirs are capped by a dome of impervious rock that retains the content of the reservoir. To get to it we have to drill through the cap. Aeschbach-Hertig mentions ground water. He may be referring to artesian reservoirs in strata that at some point come to the surface or are not capped with completely impervious layers of rock, allowing the gas to percolate up to the surface over relatively short periods of geologic time. Many gas reservoirs already contain significant proportions of CO2 that has been naturally produced and trapped with hydrocarbon gases.
In other words these two views are not necessarily contradictory.
Surely, the best way to store carbon in a mineral format would be to use some kind of solar capture system to drag the CO2 out of the atmosphere and the oceans. If it were natural then so much the better.
Don't we already have a solution? I think it's called algae in the sea, and trees on the land.
We just have to kill of lots of trees and algae and bury then for a million years every now and then. (I think we do the killing bit somewhat to well already what with acid rain and oceanic pollutants etc. So I guess we're killing the wrong stuff and not burying it properly)
This would create loads of coal, gas and oil for future generations.
You don't have to worry about future generations being tempted into using this fuel though because it takes a few million years for the cooking process to mature the carbon the way we like it. And by the time it reaches maturity we will have solved the problem or will have killed most of the planet anyway.
....or would it be cheaper though to move us all to mars?
I'm not a chemist, but it seems to me that...
Methane doesn't react with water, however, carbon dioxide does, creating carbonic acid.
Carbonic acid will react with calcium carbonate (limestone), forming calcium bicarbonate.
Calcium bicarbonate is water-soluble, but it unstable. If the carbonic acid is removed, then the calcium bicarbonate will break down to carbon dioxide and calcium hydroxide.
This is the process that produces stalagmites/stalactites. Carbonic acid is more stable under pressure. If the pressure is reduced, then calcium carbonate is produced, which will settle at the bottom of the aquifer. I suspect the pressure is cycled then the calcium carbonate will tend to be dissolved from the top and sides, and deposited at the bottom.
How long this would take to move the aquifer to its roof is a different matter.
"What we need are photo-electric CO2-> Carbon converters, since photoelectric tech is orders of magnitude more efficient at extracting solar energy than plant photosynthesis."
Nah, soylent trees are 100% efficient, you do ZERO work to grow them. I think it's some sort of magic tree fairy. If you leave a field alone it grows bushes, then overgrowth, then trees, all by magic with no work at all!
Not only that, the production of soylent-tree from trees is even easier, just wait a little longer and the soylent fairy does it for you.
Amazing! And these fairies have been doing this since long before man arrived on the planet!
Remember, "Soylent trees are made of ..... trees..... there's a hint in the name..... what did you think they were made of people? Are you nuts? Why would I call them soylent-TREES!"
:)
The efficiency is irrelevant. It's the total system scalability & cost that matters, and for that, plants beat any conceivable man-made thing on both counts. Efficiency in general is an academic concern, not a practical one. In industrial PV installations for example, solar cell efficiency in 99% of applications is irrelevant, and only cost-per-watt matters.
I agree totally with your points about how plants are conveniently self-replicating, scalability, cost/watt etc.
But trees are not free (whether to manage, use, or bury), so the enormous difference in efficiency _might_ allow scope for a useful mass produced PV->carbon-fuel system. Especially since growing trees in the desert can be non-trivial -- but there is lots of solar energy.
The only time the efficiency of photo-voltaics matters... is if you're trying to generate an awful lot of energy with them, and therefore they're competing with land you could use for growing food.
This may not have been the case in the past, but if one intends in the future to make an appreciable dent in the carbon footprint with solar power, it will matter.
Imagine a 500MW coal-fired power plant. I live nearby one. Just think about the chimneys. How power-efficient would it be to pump the whole huge volume of exhaust gasses underground? How deep are the gas wells? How many metres of "water pillar"? It's one Bar every 10 m. Imagine that you'd need to compress a powerplant chimney worth of gas up to hundreds of Bars to pump them underground. Think about the heat produced, apart from the potential energy stored in the pressure difference. Does that seem worthwhile? Wouldn't it take more energy than the power plant would be able to produce?
Or, would you just take some water from down under, let the exhaust gasses bubble through it until most of the CO2 dissolves (and nitrogen bubbles back up), and pump the water back down to where you got it? That might be a tad more efficient... But, would the water take any further CO2, at our surface pressure?
Any solid data on that? URL pointers? Too lazy to do the basic maths myselfs...
For every proven oil well that's drilled, there are several that will never produce a drop of petroleum. A good number of these end up in brine reservoirs which have been sitting there for millions of years. Pump CO2 down into those then fill the well with concrete and it should remain there for ages. Not only because CO2 dissolves into water, but also because CO2 under high pressure is a liquid at normal temperatures.
This wonderful, much misunderstood molecule is now under attack from all sides. The fact that people are seriously discussing removing it from the atmosphere is in my view the height of unbelievably stupidity and goes to show that, as pointed out in a recent scientific paper, Rationality is thrown out of the window when normally sane people are confronted by so-called "experts".
The cretinous Climate Change movement, burning technocracy, industrialisation and modernity as it continues to destroy any remaining trust in the Scientific Method, has based its entire argument on a demonstrably false premise. That it is false is now quite obvious to anyone with an enquiring mind.
When our descendents look back on this period, they will wonder about us with bemused amazement; that is if our descendents survive the other, orders-of-magnitude more pressing problems Humanity is facing.
Whats with these fucking greenies, Name 1 product that does not use on average 5 times the resources to be made green. Yep even google cant find a result for that.
We as a human NEED carbon, 6 billion of us breathe it out all the time. in fact its what triggers all mammals to breathe, so thats what 6 billion sources of carbon. I dont know how much the average human uses etc and i cant be bothered to look it up to be a smartass, yes the industrial world has probably done damage, but us mere humans should fuck off and leave it be, when man plays with nature it never ends in good things.
Global warming and filling the sea with carbon its about £££, from the sensible research yes the earth is changing climate, but records show it does that quite often, and its been overdue for many years. Before global warming i remember the "we should be about to enter ice age"
"Name 1 product that does not use on average 5 times the resources to be made green."
As James Lovelock has pointed out, biochar from pyrolysis of domestic and agricultural waste looks very promising. Besides doing the carbon capture bit, it can be used to improve depleted soils. Because it also reduces waste of fertiliser it would be cost -effective and energy-efficient in its own right.
With <<published as a letter to heavyweight boffinry journal Nature>> you make it sound like "Disgusted in Tunbridge Wells" sent in his usual raving lunacy.
However, "letter" is the title that Nature gives to unsollicited original work, as opposed to for example "commentary" one is asked to write, or a "review" of other people's work.
"..reasonably points out that if an old gas field could hold onto its gas for thousands of years, it's reasonable to think it might hold onto fizzy water too"
Bit of a leap of faith here surely? The way we are currently sucking gas out of many of our aging fields we are actually damaging the formation.
The gas may have sat there nicely for millions of years, but when we start drilling multiple holes into the same field it damages the reservoir.
Add to this the fact that when a field is largely depleted we can no longer rely on the gas freely flowing so we resort to applying a pressure differential to the top of the well (think of sucking through a straw). The more we do this, the more we see solids being produced by the wells. These solids are the first signs that we are damaging the reservoir. Now quite a few of the wells I know of produce solids. In addition there are plenty of wells where concrete liners etc have become deformed due to downhole damage.
Basically we have raped the gas fields to within an inch of their lives, so don't bet on being able to just pump down a shit load of CO2 and expect it not to leak.
Expect the North Sea to become like the Bermuda Triangle as lots of ships suddenly disappear mysteriously....
Can't remember where I read, but sometime ago I saw an article - theoretical - about a weapon to kill a warship. Thousands of pipes, drilled with holes, blowing compressed air under a ship. Boyancy down the tubes, ship floats like a brick.
So, if there's so much CO2 in the sea then, all the enemy has to do is release a few tonnes of sugar at the right moment. (Tried for a joke, lobbing a sugar cube into your mate's coke??)
Back to the Kon-Tiki concept, I guess. Except, natch, no smoking on board.
Slight problem with this plan is that the otherwise perfectly competent cap rock in any North Sea hydrocarbon reservoir has fairly big holes in them called "wells". Contrary to popular belief, these aren't just holes, they have to be completed with alloy jackets to provide integrity and control to the surface. As any drilling or completions engineer worth their salt could tell you, the completion jackets of most of these wells that have been, or will be abandoned, will quickly rot in the mildly acidic formation water that results from such a scheme. The outcome: large swathes of the North Sea become no-go areas for shipping of any kind as these old wells blow out and spew CO2 to the surface.
Then there's the infrastructure. We could use the gas pipelines to pump the gas out there, then the platforms themselves to inject. Simple, right? Well, wrong, these pipelines and facilities are only designed to take low concentrations of CO2 - start at 4% mol and work your way down. There is no way in God's Earth this will work without ripping out most of the infrastructure out there and re-abandoning most of the wells at astronomical cost.
We should be looking for shallow, onshore aquifers for this kind of thing, not offshore, where the costs will skyrocket. Anybody who suggests anything else is either ignorant or a liar.
I find the whole notion of CO2 being evil as odd.
The Greenhouse Effect is what brings LIFE to the Earthen biosphere. If there is no greenhouse effect, every living thing on the planet would die.
Let's take what concerns people, the most, about CO2, and seriously consider it.
CO2 is a negligible greenhouse gas, in comparison to Methane, which has a much greater greenhouse effect. We can (and should) use methane as a fuel (converting Methane to CO2, while capturing the energy, by burning it will actually cool the earth.) What is odd - some bozo's actually think that the production of CO2 is a bad thing, while not burning methane actually makes things worse, by their own standard!!!
If it is true that the Coal and Oil sequestered under the ground was originally plant life on the surface of the earth, then releasing it to be used at the surface should be returning the Earth to a more natural state. Isn't a more natural Earthen state desirable? Isn't this the standard that most conservationists use? Why are they against returning the Earth to a more desirable, former, state?
A gradual increase in CO2, above the earth's surface, allows for plants to grow more efficiently, and produce more plant material, to feed animals from. Isn't more food desirable??? Do people just want plants & animals to starve to death???
CO2 makes plant life grow more vigorously. Greater plant life can be used to create energy from more renewable resources, allowing for greater use of Ethanol, Bio-Deisel, Bio-Mass, etc. Isn't this the goal, to use more renewable resources???
The sun is the source of energy most used on the Earth. Carbon is the element that allows the Earthen biosphere to harness it. CO2 feeds plants, that capture the sun's energy (free-of-charge.) It seems crazy to me that people are trying to sequester CO2, when living things on the Earth NEED the energy that CO2 is critical in the process pants use to capture solar energy, for all things living to use later use!!!
I am quite tired of the weirdos with their green clothing, just trying to kill everything alive. They are little more than Death-Merchants.
To put things into perspective, a pre-combustion capture power plant that produces 500MW might have a total 'parasitic load' of approximately 120MW, leaving 380MW of net power exported to the grid. CO2 would typically be compressed to about 150 times atmospheric pressure, so that it becomes a 'dense phase fluid' (very similar to a liquid) and then it is easy to transport. You are correct that the carbon capture and compression consume a significant amount of energy, but there are still commercial-scale power plants with carbon capture being planned; it is relatively simple technology.
On the storage side, it is very important to distinguish between injection into saline aquifers and injection into producing / depleted oil and gas reservoirs. Oil and gas reservoirs are relatively well-understood in terms of seismic data, and have an impervious layer of cap rock that has kept the oil/gas/water in situ for millions of years, whereas saline aquifers may carry the risk of CO2 migrating to the surface. I do not believe this article makes that distinction obvious for the reader.