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Carbon Removal
8

Carbon Removal

Carbon Removal

(OP)
thread730-443054: Carbon Capture and Sequestration
CO2 can be removed from the atmosphere and separated into solid carbon and oxygen gas. Essentially unburning carbon.
Switching to renewable energy sources will reduce CO2 emissions however it won't remove excess CO2 in the atmosphere as a result of the combustion of fossil fuels.
2Mg + CO2 ⇌ 2MgO + C
Solid carbon submerged is relatively inert and compact.
Electrolytically recovering the Mg and collecting CO2 will require energy from renewable sources. This is the mechanism that I propose. Does anyone have any arguments against using it to sequester atmospheric CO2?

RE: Carbon Removal

Do you have the ability to process about 0.4 trillion tons of carbon this way?

One estimate is that 441.5 Pg C (petagrams of carbon)/441.5 Gigatons of Carbon (metric tons) has been added by clearing trees and burning fossil fuels.

https://cdiac.ess-dive.lbl.gov/pns/faq.html

Have you developed a rough estimate on energy and facilities required for the processing a gigaton of carbon?

RE: Carbon Removal

(OP)
At this point everything is theoretical. I'm here to invite you to challenge the concept.

I've calculated 9110 kWh per tonne C.
This is at 100% efficiency.
I propose that calcination of MgCO3 be used to collect and concentrate CO2.
It's difficult think of the scale but the problem is approaching incomprehensiblity. The solutions may have to approach impossibility.

RE: Carbon Removal

The production of mettalic magnesium is incredibly energy intensive. Have you factored this into your thinking??? Somehow I think not

RE: Carbon Removal

(OP)
Do I have the ability to process 2400 Gt of CO2? The answer is no. It's going to require about $5 a person per day for 30 years to do the job. Unfortunately we are going to have to pay up or suffer the consequences.

RE: Carbon Removal

(OP)
The problem isn't the mechanism. The problem is the capital investment to build the infrastructure and a design to maximize efficiency. Energy recovery at each step. Energy infrastructure development over the next 30 years could be exponential. Renewable energy cost for survival might be placed in a unique cost category. The cost may be inversely exponentially lower even without subsidies.

RE: Carbon Removal

(OP)
If we can built multiple reactors executing this mechanism using clean energy all the excess atmospheric CO2 can be processed.

RE: Carbon Removal

(OP)

RE: Carbon Removal

That's 9.1 GW-hr per ton, onto 441.5 Gigatons of carbon - lessee, carry the 1, and ...

The Earth intercepts about 173,000 teraWatts (trillions of Watts) of solar power, or 173*10^15 Watts. That comes to 4*10^18 Watt-hours per day.

Your proposal takes 4*10^21 Watt-hours of energy, so the entire intercepted solar radiation on Earth for 1*10^3 days, about 3 years that not one photon from the sun is allowed to land on Earth; complete blackout.

Seems reasonable. Moving it to 30 years means only 1/10th of the solar radiation needs to be converted, but the conversion is still only 30% efficient, so 1/3rd of the cross-section area of the Earth needs to be used to intercept the sunlight, but that needs to be from every angle as the Earth turns, so a cylinder maybe 3000 miles wide (1500 miles on each side of the equator) completely encircling the planet should do the trick. It will, of course, produce 100% shadow for those 30 years under that belt, but all should be good afterwards.

So 3000 miles * pi*8000 miles = .08 billion square miles of solar cells.

Figure 10*10^9 people, that's roughly 21,000 square feet per person. $5*365*30 = $55,000 per person, so the solar cell price, installed (crossing the oceans is extra) can be no more than about $2 per square foot.

Altogether it looks entirely realistic. I wonder why no one is working on it.

(edit because it's 2*pi*R, and pi*D, for the circumference. Long day for a megaproject. )

RE: Carbon Removal

By the way, where does the magnesium come from?

RE: Carbon Removal

I'm afraid, the world is in for some serious heartburn...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Carbon Removal

I think I can afford $5 a day, but can people in other places afford that?

Would it not be cheaper to grow trees and burry them when they die?

RE: Carbon Removal

Spend the money terraforming Mars.

RE: Carbon Removal

Agree, cranky. But you don't have to bury the trees right away, just don't burn them, and bury the waste once the wood products have reached the end of their usefulness.

RE: Carbon Removal

I have a 30 foot tree - the local dumps/tree services are seem set to want $500 to bury what is about 200 pounds of carbon in that tree. It's insane.

RE: Carbon Removal

Maybe I do differently. I burn wood for heat, but I find some amount of charcoal in with the ashes, which both go to the landfill.
So I get to heat my home, from trees that are dead, problem trees, and from what someone else cut. The ash and charcoal go to the landfill.

I tried collecting charcoal, but after problems storing it, and having enough, I have had enough of it.

We also send pine needles to the landfill, again because we have enough of them.
But I do add cheap fert back to the area, so I don't completly depleat the soil.

RE: Carbon Removal

(OP)
@3ddave. Thanks for the math.
2Mg+CO2⇌2MgO+C
441.5 x 48.61/12 = 1800 GT Mg
I'm using tons here.
I need about 570000 tons of Mg assuming that a lb of Mg takes 5 min to convert to MgO on pure CO2.
About.04 grams of Mg per person.
Or 950000 tons of MgO.
About .06 grams MgO per person.
The Mg is just a buffer atom. It's convenient due to its oxidation state.
The Mg⇌MgO equilibrium will be maintained by the electrolysis of MgO. Super heated CO2 injected into the molten cathode of the cell. O2 being released at a carbon anode.
Carbon should float up through the molten MgO and collected anaerobically to avoid C+O2 back reaction.
I need a million tons of MgO.

RE: Carbon Removal

(OP)
@cranky108 80 20 rule. We may have to find $20 per day.

RE: Carbon Removal

(OP)

RE: Carbon Removal

(OP)

RE: Carbon Removal

(OP)
Q - kiln MgCO3⇌MgO+CO2
R - pure CO2 tank
J - Molten MgO
K - carbon anode
L - molten metal cathode
O - CO2 injection site
M - carbon to be submerged H2O

RE: Carbon Removal

Good - the Mg is all sorted out. 1 Million metric tons is the entire world's annual production.

Where's the energy coming from? You seem to have skipped that part.

And where does the cooling come into play - all that superheated material needs to be cooled somehow. Where does that heat go?

I do like the part where the carbon "should" float up. Seems like an easy experiment to run before committing to this technology.

RE: Carbon Removal

(OP)
Density MgO 3.58
Density C 3.52
Kind of close but might be enough.
Energy can be solar, wind, geothermal, hydro, tidal, perhaps nuclear.
I don't think we can afford cooling. Don't want to lose energy in the MgCO3⇌CO2+MgO reaction. Want to recover energy from 2Mg+CO2⇌2MgO+C for electrolysis of MgO.
At 100% efficiency CO2⇌C+O2 393.5 kj/mol is the net reaction.
100% isn't realistic. No reason to settle for an arbitrary efficiency number unless there is a physical law that dictates.

RE: Carbon Removal

(OP)
This is just a machine. We're good at building machines.

RE: Carbon Removal

(OP)
@greglocock can you suggest a more appropriate site.

RE: Carbon Removal

(OP)
@mintjulep yes I agree. I question the neutral philosophy of carbon fuel production. Sequestration of O2 in the CO2 isn't the correct solution. We aren't even addressing the O2 in H2O from combustion. Who would have thought that we could influence the amount of CO2 and O2 in our bubble?

RE: Carbon Removal

Suggest the OP studies the Magcan plant , just south of Calgary. Metallic magnesium was produced from MgCO3 Rock. Place went bankrupt despite very large subsidies from the government.

RE: Carbon Removal

2
The sun provides roughly 10,000 times current human energy production. To make this a 30 year project takes 10% of that power level - so humans need to find a source that is 1,000 times larger than is in current use. Since wind and hydropower are solar powered, tidal has definite limits (it draws power from the Moon's orbital energy; how much before that changes?) that leaves nuclear (not happening, they keep going off line for a bunch of technical reasons) that leaves geothermal to get about 100,000 times more than it does now.

Even a 300 year project is 100 times the current energy production. That's not going to happen.

Density MgO 3.58
Density C 3.52

Is that at the process temperature for the MgO and is there proof of that? What is the solubility of carbon at the process temp? Should you have already demonstrated this on a smaller scale?

The water in Alberta should be checked. There's too much LSD leaking in.

RE: Carbon Removal

(OP)
@miningman yes sounds like I've got a good source of MgO near Radium. I've read a bit about that project.
Carbon removal to correct the excess in the atmosphere is going to be a difficult sale. I seems like governments are providing incentives and directives to reduce CO2 emissions. It's going to be harder to find someone to buy the pile of carbon beside my electrolytic tower.
Magcan didn't fly. I'm not trying to produce Mg. It's just part of a mechanism to ionize CO2 and scavenge the O2.
When society buys into a working mechanism they'll be buying wellness not carbon submerged in an old coal mine. This isn't going to be free. Photosynthesis used to be free. We are taking that off the table. I don't think we are going to be able to hydrospore the world with photosynthetic yeast to reverse a bad decision to use combustion.
I think we are going to have to build reactors, expend energy, and pay for it.

RE: Carbon Removal

(OP)
@3ddave that's what I was hoping for. I needed to bounce this off of people with expertise to test the logic.
So unsound mechanism and not enough energy in the world to do it. I actually thought it was possible. At least now I can stop.

RE: Carbon Removal

(OP)
2019
world energy kwh/yr
1.71E+14


Gt Carbon
655


tonnes Carbon
6.55E+11


kwh/tonne
9110






total kwh needed
5.96705E+15


kwh/yr 30 yr
1.98902E+14


fraction world yr production
1.16E+00


solar available kwh/hr
1.19444E+14


solar available kwh/yr
1.04633E+18


fraction solar yr available
0.000190094


area half earth surface sq m
2.55E+14


area required sq m
48473964638


m long m wide
220168.0373


width equatorial solar panels in m
2419.162303


Sorry I gave up too soon.
Big numbers.
And yes I should have done the math.
3 km wide around the earth.
About 7 sq m of panels per person at 100%

RE: Carbon Removal

(OP)
😀

RE: Carbon Removal

C'mon- the obvious solution here is just to turn all that CO2 into diamonds and oxygen!

Small thermodynamics problem there, but that's all just details! There's plenty of energy from the sun!

Sorry folks, but it's tough to take any of this stuff seriously. The very reason we make CO2 as a product of energy producing reactions is the same reason it's a difficult feedstock, in energetic terms, to make anything of value from- even if you're satisfied with making artificial coal instead of diamonds.

RE: Carbon Removal

For carbon sequestration it might be more effective to capture the CO2 at the source; eg. Shell's Quest carbon capture project captures about a third of the CO2 emitted by the scotford upgrader in Alberta.

For removal from the atmosphere, plant trees. Build things out of the trees. Plant more trees. Bury the things you built out of the trees when they are no longer useful?

RE: Carbon Removal

Better still make char from the waste trees or tree derived stuff and bury that, using the pyrolysis oil and vapor as a fuel to replace the transport uses that can't be electrified. Shell/GTIs IH^2 process is particularly good.

Especially don't burn or convert waste plastics to fuels to burn- recycle what you can and bury the rest. Plastics are 200% fossil origin and landfilling them is the cheapest and lowest impact post consumer fossil capture imaginable.

(www.spitfireresearch.com)

RE: Carbon Removal

As I burn wood for heat, I have been told many times that wood is such a dirty fuel source. Why don't you use natural gas?
I normally have charcoal as a waste as the fire ends late at night. This gets landfilled.

I think we should do the easy things first. Biogas is nearly 50% methane, and nearly 50% CO2. And since real natural gas must be processed to remove other gases, and to blend it, the biogas can be a stand in for real natural gas. The CO2 can be used for many things, including improving plant growing in green houses.
Or the biogas can be used as a heating fuel in greenhouses directly, in what has been called suicide heaters.

So why start with Rup Goldberg projects?

RE: Carbon Removal

The CO2 from burning wood is not an issue. It was in the atmosphere between 1 and 100 yrs ago, you're just returning it as part of the carbon cycle.

Wood ash and char are excellent agricultural soil amendments when used properly.

The soot, NOx, CO etc. is a matter of HOW wood is combusted. A catalytic woodstove has pretty reasonable emissions but you certainly wouldn't want every house in a dense urban area heating with wood. Thank goodness there are heatpumps so we don't have to burn stuff every time we need low grade comfort heat, though of course if you ignore the cost of CO2 disposal to the atmosphere, natural gas is a very cheap fuel and hard for anything else to compete with.

(www.spitfireresearch.com)

RE: Carbon Removal

Because my soil tends to be too low in the PH range. wood ash does not make a good soil amendment here. So it is land filled with the other trash. If you know of anyone who wants it, and is willing to pick it up, let me know.
Natural gas is not an option where I live, as I don't live in town.
Other heat options are propane, or electric. I suppose if I tried hard enough, I could get coal, but wood is much easer.
Besides, I use mostly waste wood that has been cut by someone else. I just pick it up and process it (cut, split, and stack).
Also available to me is construction waste, but those 2X4 cutoff's burn too fast.

I think pellet wood stoves is a good way to reduce waste wood, and heat a home, but the plastic bags they come in is a problem. Maybe if there was a delivery service that would fill a bin, like the oil services back east (or so I hear).
Most pellet stoves lend themselves well to a computer controller, and a thermostat control.

I did have one years ago, and the problem is the price break was at purchasing a ton, but I only have a half ton pickup.
It produced very little ash, which was nice, but parts were hard to get for things like blowers, and no service available.

RE: Carbon Removal

Wood ash will raise soil pH- it's a good amendment for that purpose, unless you want to grow something like rhododendrons or conifers.

(www.spitfireresearch.com)

RE: Carbon Removal

Maybe I have the PH scale back words.
I need to add acid to my soil. Wood ash tends to make the soil so that only weeds grow.

RE: Carbon Removal

If your soil is too alkaline and you need to add acid, you're in a lucky situation. Just decomposing organic matter tends to lower soil pH. But yeah, in that case you wouldn't want to be adding wood ash. Most people have it the other way around- not enough carbonate in the soil to buffer pH and the impacts of previous acid rain etc. leaving soil pH too low to grow some things.

(www.spitfireresearch.com)

RE: Carbon Removal

1. How was it determined that there is excess CO2 in the atmosphere?
2. Haven't ice cores and ocean sediment sample found higher and lower CO2 concentrations in the past?
3. Didn't James Croll explain that the wobble of the earth, the feedback of snow reflecting heat back into space, and the spirograph type orbital patterns of earth around the sun over time leads to major climate change (Ice Age(s)) over time?
4. Is it not true that a unit of land with grass growing has more chlorophyll than an equal unit with trees? More chlorophyll equals more CO2 removed? The same ratio is for algae to grass to trees?
http://www.rebresearch.com/blog/james-croll-janito...

RE: Carbon Removal

Do we have to go through this crap again?

RE: Carbon Removal

Interesting note, grass has about the right ratio of C/N for composting. Or making biogas. Save your lawn clippings, they might become valuable.
Problem with trying to grow grass, is it needs lots of water, and many places just don't have the water.

Natural trees is the answer. No work feeding then, or watering them. And harvest is a one time process.

RE: Carbon Removal

The climate of the Earth is difficult to characterise and measure. One subset of climate is the average global temperature over a suitable time period, measured near the Earth's surface. This temperature has varied historically over a wide range. It is affected by many factors, both known and unknown. The main factor is the albedo of the Earth and the incoming energy from the Sun. These two directly interact and the combined effect raises the temperature of the Earth by about 250 deg C, from the background temperature of space which is about -270 deg C . The next most significant effect is the greenhouse effect of the atmosphere, which raises the temperature by about 33 deg C. This is due to several mechanisms associated with turning incoming EM waves into heat (badly phrased) , and also complex interactions with the heat radiated by the Earth's surface, and probably some other knowns and unknowns. The greenhouse effect is affected by the gaseous composition of the atmosphere, and clouds. The most important gas for greenhouse is water vapour, approximately 80% of the non-cloud greenhouse effect is due to that. Water also directly affects the albedo of the Earth by forming clouds and snow and ice. Of the remainder the majority is due to CO2. In the absence of any other effects a further doubling of the proportion of CO2 in the atmosphere would be expected to raise the temperature by rather less than, but approximately, 1 deg C. However, this is a very weak effect and is easily dominated over any timescale from hours to hundreds of millions of years by the many known and unknown factors. There may be positive or negative feedbacks associated with temperature changes, which may modify this 1 deg figure. There are certainly simple feedback effects associated with CO2 levels, eg the greening of the Earth (https://www.nasa.gov/feature/goddard/2016/carbon-d...) which will affect both the Earth's albedo and weather patterns. On the other hand the melting of the Arctic ice cap will reduce the earth's albedo, so that's a positive feedback. One other overwhelmingly strong effect on an hourly to century timescale (at least) is the interaction between the oceans and the atmosphere. The thermal capacity of the oceans is about 1000 times that of the atmosphere. That is, cooling the ocean by 0.01 deg C (that's the limit of resolution of a thermometer typically, accuracy is perhaps 0.1 deg C) would provide enough heat to heat the atmosphere by 10 deg C. The interaction between oceans and atmosphere is hugely complex and data is lacking.

As to where the CO2 comes from - if you add up all the CO2 emitted by burning fossil fuels since 1880, it is about twice as much as the change in CO2 in the atmosphere. According to the DOE we've emitted 389 E12 kg of C. In that time the ppm of CO2 has increased from 280 to 400 and the mass of the atmosphere is 5.1480E18. The mean molecular mass of the atmosphere is 29 and CO2 is 44 obviously. So the mass of CO2 in the atmosphere has gone from 280E-6*44/29*5.1E18=2.2E15 kg to 400E-6*44/29*5.1E18=3.1E15 kg

And from the above we've created 389E12*44/12=1.4 E15 kg, of which 0.9E15 is still in the atmosphere (glad that came out right!)

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Carbon Removal

What I'm waiting for is the exposure and release of truly amazing amounts of methane that has been trapped in the permafrost; methane is significantly more effective at capturing infrared radiation. In thermal cameras release of natural gas can appear opaque. When Alaska and Siberia all rot the pace will really take off.

RE: Carbon Removal

2
The "natural " way to sequester carbon is to grow trees. What is more important is that the argument that anthropogenic CO2 is warming the environment in a significant or negative manner is technically incorrect.

Refer to Youtube videos by Nir Shaviv, Henrik Svensmark and Murry Salby for the technical presentations of how the earth's climate is primarily modified by the amount of low level ( tropospheric) clouds, and how the amount of clouds is related to the amount of cosmic radiation recieved by the earth. That radiation varies over time as the earth( and the solar system) moves closer to ( or farther from ) supernovas ( over millions of years) and also the strength of the sun's magnetic field , which varies over centuries. The current low level of solar magnetic activity points to a coming reduction in earth's tropospheric temperatures over the next 40 yrs ( similar to the Maunder minimum). This will likely lead to crop failures as the growing season shrinks, and history records such climate cooling events with coincident crop failures. The computer models used by the IPCC do not recognize this effect and as a result all of its predictions and claims have been proven false. It is amazing how many times they can cry wolf and anyone pays attention to them.

Higher levels of CO2 improve crop production, and consuming additional energy in order to remove CO2 from the atmosphere not only harms crop production but also increases the rate at which we consume finite fossil fuels. The main problem that current society faces is not global warming, but is the need to adjust the rate of consumption of fossil fuels so as to enable a stable future for society. While most of the measures proposed to stop "climate change" are also consistent with the reduction of consumption of fossil fuels, the idea that we need to remove CO2 from the atmosphere is actually the worst thing we should be doing.In economic terms, the primary economic driver for removal of CO2 is for its industrial use in tertiary oil recovery and proposed methanation of hydrogen derived from electrolysis.

Another side comment on the false "climate change" issue includes the fact that the historical record for CO2 vs time and Temp vs time demonstrate that the temperature changes first and the CO2 changes about 800 yrs later ( due to de-gassing of CO2 from the ocean) .

Other "limits to growth" that may be feeding the eugenicist's fantasies and may be used to justify the ongoing measures to lower fertility include a limit on available fertilizer components and a loss of control of information to the masses ( internet) , similar to the social changes that occurred after the Guttenberg printing press. May you live in interesting times.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

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