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Carbon Capture and Sequestration
8

Carbon Capture and Sequestration

Carbon Capture and Sequestration

(OP)
Hi all,

Is there a forum on this community dealing with carbon capture and sequestration?

This is a huge potential industry and we need it. I'd like to read up on the current engineering problems and solutions.

Thanks and cheers,

RE: Carbon Capture and Sequestration

(OP)
Yes. Did I miss it?

RE: Carbon Capture and Sequestration

(OP)
Haha, I understand how to Google the words. I was wondering if there is any engineering forum / topic areas dedicated to it on this site. In my spare time, I will be attempting some carbon capture and sequestration.



RE: Carbon Capture and Sequestration

(OP)
Also, when fall arrives and your tree vacuum loses its leaves, CO2 is added back to the atmosphere. When your CO2 vacuuming tree dies, it most likely decomposes and also releases its CO2 back into the atmosphere.

Trees aren't a great solution for putting CO2 back into the ground, hence the interesting engineering problem of somehow getting CO2 out of the air and then keeping it out of the air.

RE: Carbon Capture and Sequestration

Well, I didn't intend the "tree" to be only a joke. There is serious investigation of large scale forest management for sequestration.

Anyway... on Eng-Tips, since 9 May 2000, there have been exactly 52 threads that include the words "carbon sequestration". So, doubt you will find much discussion here.

Perhaps you will want to read about the seven advanced "Carbon Capture Technology" projects the US Department of Energy announced (16 Feb 2018) that they will be funding.

or, Drax Electric Power Station project announcement (21 May 2018).

or, maybe the Petra Nova facility that began operation in January 2017. One of only two operating.

Another is the 110 MW Boundary Dam plant. The second operating station.

Kemper abandoned plans for capture in June 2017.

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Carbon Capture and Sequestration

There may only be 52 threads so far but maybe because there isn't a specific forum for that topic.
On the other hand there are forums here that aren't that active either.

I've Ref Flagged your post and asked management to review your question.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

RE: Carbon Capture and Sequestration

Carbon capture and sequestration is an "industry" only in the sense that it is being studied by people for money.

It is also, in my opinion, a dangerous distraction from what we really need to be doing, which is focusing on the elimination of the burning of fossils directly for energy.

A simple mass balance will explain why: just look at how much fossil carbon we're burning each year for energy right now, convert that all to CO2, and calculate a volume as a liquid. Now try to imagine finding a new hole that big, somewhere on earth, each and every year.

Any process which is going to store CO2 in a form other than as CO2 itself is going to require energy. That begs the obvious question: why not avoid wasting that energy and simply use whatever source you were planning to waste on converting CO2 to something else, into a means to replace the fossils we're currently burning? By so doing, you'll not only avoid the CO2 emissions, but also all the toxic emissions that inevitably come along with burning fossils!

Thermodynamics explains why the fact that CO2 is a desired combustion product, also necessarily makes it an undesirable feedstock for almost every chemical or material. A handful of highly oxidized species may make sense to make using CO2 as a feedstock, i.e. working backwards from a thermodynamic point of view- but it's quite a small handful, none of which would be reasonably consider to be a fuel. If you want a fuel, you'd be better off starting with literally ANY other form of carbon than CO2 or carbonate. Of course if we are going to ignore thermodynamics, we should simply convert all the CO2 to diamonds and oxygen and go have a beer.

Once we've stopped burning fossils for energy directly- hopefully in the next 50 years- we can start talking about processes to enhance the rate at which nature takes CO2 back out of the atmosphere.

The limited natural capacity we have for storing CO2 as a gas, we'll need just to satisfy our desire to keep roasting carbonate rocks to make cement etc.

RE: Carbon Capture and Sequestration

Plus the atmosphere would run out of oxygen. I don't see any better solution for the surplus CO2 other than photosynthesize it all back, whether we have the trees do it or whether we help them somehow.

RE: Carbon Capture and Sequestration

(OP)
Moltenmetal,

We need both CO2-less energy and carbon capture. I think it will be an entire menu of options if we want to solve the global warming problem.

There are people focusing on how to capture all the CO2 exiting power plants.

Unfortunately, even if we stop producing all CO2 today (or capture it 100%), the earth will still go thru a big warming cycle. If we continue as business as usual for 50 more years, we're possibly dooming ourselves to either barely surviving as a species to possibly not surviving at all. I think it is estimated that a business as usual would be an increase of 4 C by year 2100. We're melting permafrost and glaciers and acidifying oceans with 1 C increase. It's not going to be pretty.

Scientists agree that the polar bear is already extinct and coral reefs are doomed, for example. Ocean acidification is going to cause huge problems. Droughts are getting worse (Syria civil war, California wildfires). Sea levels will rise. At some point methane release from permafrost and the antarctic ice sheet will cause a strong negative feedback loop that we may have a really hard time stopping, even while taking CO2 out of the atmosphere.

At this point, we need more than stopping CO2 production, we need negative CO2 production.

We're working with microbes to see if we can create carbonate -> calcium carbonate (limestone). As far as I know, the big companies are using chemistry (which is probably smarter, but microbes are so cool). Biggest challenge is (obviously) making a process that is a net CO2 negative. The companies right now are producing a product instead of burying the CO2. One company makes rocks to replace gravel, I think. It doesn't really matter as long as the CO2 stays out of the atmosphere.

We took stuff out of holes, we can put it back in.


Slide Rule Era,

That's interesting. I'm going to take a look. I did hear about farming techniques that could help pump CO2 back into the ground via plants. Maybe this is similar?


Cheers,

RE: Carbon Capture and Sequestration

Much as I like trees they are a con when it comes to carbon capture. They live for a few hundred years at most (and as a commercial venture more like 50) at which point all the CO2 they have sequestred is temporarily stored as wood or paper, or released immediately back into the atmosphere as it decomposes.

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 Capture and Sequestration

Permanent reforestation of large areas where trees were removed years ago is where the interest in carbon capture and storage is centered. I agree, trees come and go, forests have long term potential. The potential benefit is modest, but can be done. Here is one paper: "Carbon Capture and Storage in Forests".

Trees... forests... these are "small potatoes". The big push for carbon capture and storage is for coal-fired electric generating stations. I'm a novice reading about carbon capture/storage, but do have a fair amount of first-hand experience with design, construction, (and to a limited extent) operation of coal-fueled electric generating stations in the USA.

As a fuel for the future, coal is GONE, and it has nothing to do with technology, politics or the environment. The economics for coal vanished about 15 or 20 years ago with low cost natural gas becoming available.

1) The best coal plants are about 34% Correction: 47% + (thermally) efficient. A combined cycle natural gas is at least 50% efficient... over 60% can be done.

2) A modern coal plant would cost (if any were to be built) about $2 to $3 million per megawatt of gross generating capacity. A natural gas plant, about $1 million per megawatt.

3) Natural gas burns cleaner than coal. A modern coal plant has a precipitator for fly-ash removal, scrubber (flu gas desulfurization) to remove sulfur compounds, SCRs (selective catalytic reactors) to remove nitrogen compounds. This equipment consumes a lot of electric power (parasitic losses). Current technology for carbon removal requires even more power. For reference, a coal plant has about 10% total parasitic loss (e.g. a typical existing, modern 600 MW plant uses about 60 MW for it's own operation). Natural gas avoids much of this environmental equipment with reduced parasitic loss.

See Scientific American, "Will the U.S. Ever Build Another Big Coal Plant?"

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Carbon Capture and Sequestration

(OP)
Thanks!

I'll give it a look.

RE: Carbon Capture and Sequestration

SRE - the big ultra supercritical coal stations are currently achieving efficiencies in the mid to high 40's. 50% thermal efficiency isn't too far away. 34% was being achieved 40 years ago.

Low-cost gas will be short-lived, the North Sea being a great example of how to waste a reserve of clean, easily controllable fuel capable of supplying domestic and commercial for centuries by burning it in just thirty years in utility-scale power plants. One of those CCGT's paid my mortgage for ten years, but it was still a short-sighted energy policy. I think coal might rise again to fill the gap if nuclear new-build remains massively expensive.

Will nuclear fusion ever make it from prototype into commercial operation? And if it does - what will the cost be, and will it be worth it if it is clean?

RE: Carbon Capture and Sequestration

Thanks, Scotty, I stand corrected.

I don't know about a coal revival in the US, we burned low sulfur coal from eastern Kentucky, hauled on unit trains, but much of it in other places is "dirty" lignite.

Hope fusion comes along, for the last 60 years it has always been "10 years away". Things do seen a little different now.

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Carbon Capture and Sequestration

Also keep in mind, that while yes when a tree dies, part of its carbon re-enters the atmosphere, but other portions are sequestered by other organisms as part of the carbon cycle, and a percentage are sequestered by none other than the soil, which over millions of years turns it back into hydrocarbons for us to burn. Even if that value is less than 1 percent, planting forests is an easy, relatively cheap, and there are secondary and tertiary benefits aside from just carbon sequestration.

RE: Carbon Capture and Sequestration

I think Scottys comments re North Sea Gas are extremely valid but I also think that on a global scale it is too easy to be influenced by local knowledge. There are absolutely massive reserves of gas in Western Canada, and the only reason why it is not being exported to Japan today is political and environmental objections to pipeline construction. I believe the Aussies have already stepped up to take advantage of the opportunity.... liquified NG is already a huge global trade.

I also believe that coal will have its day again , but not as a conventional thermal fuel. The technology exists today to gasify coal... yes its still a fossil, carbon based fuel but it eliminates the sulphur problem. With further R+ D I believe we will have no choice eventually....theres so much of the stuff still available and all the renewables will not be on line in a timely manner.

And to me, trapping the CO2 ultimately as Calcium Carbonate makes sense, altho Im not sure if thermodynamics or entropy of the chemistry makes sense. Equally Ive never understood the basic energy aspects of compressing CO2 and pumping back underground somehow. Compressed air is such a inefficient method of energy transmission. where are the net gains coming from. Or is this another boondoggle being foisted on the ultimate consumer.

RE: Carbon Capture and Sequestration

awhicker84: given that we continue with the profligate combustion of fossils for energy, if we need to not only stop using fossils for energy but actually actively sequester atmospheric CO2 at the same time to avoid global catastrophe, you're basically saying we're screwed. There is no feasible way to store the amount of CO2 we're dumping each year, and I'm confident that we won't be inventing one any time soon either for the reasons previously mentioned in my post. Those are reasons of thermodynamics and elementary mass balance, so they're rather hard to argue against.

Again, the entire focus on CCS in past has been to allow us to continue burning fossils, without the AGW guilt- and to me, that is totally counterproductive. It's merely a way to piss through our finite, precious fossil resources even faster, because a substantial fraction of the produced energy will be needed to separate the CO2 and store it - assuming we have somewhere to store it. And if the means to store it involves converting it into something other than CO2 after the CO2 has been produced, the net energy generation will be NEGATIVE- thermodynamics virtually ensures that.

We need those fossil resources to use as chemical feedstocks. In comparison to the challenge of replacing our fossil feedstocks with renewable-sourced materials, the challenge of replacing our fossil energy use with low emission alternatives like renewables and nuclear is actually pretty easy- it's just a matter of money and political will. It doesn't even require any new inventions, although new inventions that will help are inevitable as they are being made every day.

It's a different matter to consider coking fossils to strip them of their hydrogen for energy, burying the resulting coke rather than burning it. That is in fact thermodynamically possible for everything other than coal. This approach is being seriously considered for biofuels production such that the biofuels become truly CO2 negative. Regrettably, since biofuels can't make money competing with fossils without subsidy or mandates or both, even IF they burn the char for energy, you're talking about very, very expensive energy in that case.

RE: Carbon Capture and Sequestration

Gasifying coal doesn't eliminate the "sulphur problem"- it merely makes the sulphur easier to catch in a sense. Every molecule of S in the feed coal still needs to end up removed as some other form of sulphur, and that takes energy AND results in emissions. There is nothing inherently "clean" about gasification- rather, the downstream needs for the resulting syngas usually require purification of the syngas which drives the resulting emissions.

RE: Carbon Capture and Sequestration

(OP)
I'm all for clean energy.

I'm all for carbon capture and sequestration.

Let's do it all. Like you say, we don't have the political will. Half the population thinks there is a debate in the scientific community on whether CO2 created by humans is causing global warming. It's going to be hard to get political will in that climate.

It would be really exciting if the US treated CO2 elimination and capture as the next manned mission to the moon.

Some of the carbon capture techniques can be used to replace products. One person created self healing concrete and another person found a way to create bricks using the same technique. Basically, the brick thing would save hundreds of millions of tons of CO2.

I think we are screwed. I don't think people will realize the damages they've done until it is too late to reverse it. But who knows, maybe this problem will become the next space race.

RE: Carbon Capture and Sequestration

Sorry to burst your bubble, but none of the concrete/brick examples you gave are actual NET removers of CO2 from the atmosphere. Cement starts out as carbonate rocks- and all that carbonate is driven off as CO2 during the calcining process. All these guys are doing is returning a little of that CO2 to the resulting cement in place of water of hydration- a little more and a lot faster than happens in the normal, ~ 100 yr curing process for cement products.

There is some limited geological capacity for carbon sequestration, i.e. some holes available to stuff CO2 into, and some capacity for converting olivine and serpentine to magnesite etc.- but the accesible amounts of these minerals is a tiny fraction of the amount of CO2 we're dumping into the atmosphere from fossil sources.

I hear you- it's an important problem, so you want us to do everything we can. I want us to think about what is possible and practical first, and not be distracted by non-solutions. Carbon sequestration is a non-solution. It's worse than merely being a dead end- it's a distraction being deliberately used by people who like the status quo and want to keep doing it longer.

RE: Carbon Capture and Sequestration

(OP)
I agree they aren't net removers. They help us to be able to control CO2 better. Nothing wrong with that.

RE: Carbon Capture and Sequestration

Quote:

Half the population thinks there is a debate in the scientific community on whether CO2 created by humans is causing global warming. It's going to be hard to get political will in that climate.

Interesting irony. You dismiss the notion that there is a debate, yet gripe about lack of progress. IME until you have an open-minded debate there is no progress.

In reality there are multiple debates in this realm including our species' total technology vs natural impact, the impact of one "greenhouse gas" vs another, etc. Many believe that hydrocarbon emissions are by far the worst for our atmosphere, even within the EPA, yet the EPA still pushes this notion that natural gas is a "clean" alternative to other fuels. Working in engine development, the other personal irony for me is that automobiles and combustion powerplants are commonly believed to be a source of air pollution within our cities yet in many US cities they are actually cleaning air through combustion that is dirtied by human existence otherwise.

RE: Carbon Capture and Sequestration

(OP)
Haha, sorry I was being too specific. Thanks for catching it.


"Half the population thinks there is a debate in the scientific community on whether GHG's created by humans are causing global warming."

Better?

All I was suggesting was a community for carbon capture and sequestration. Add an entire forum to the engineering behind removing / reducing GHG's if you'd like.

I'd like to move on to technical questions.

Thanks,

RE: Carbon Capture and Sequestration

I'll agree with moving onto technical discussion and will always support subforums being added (and some combined or deleted) as necessary to maintain organization and decent turnover within each subforum. My only point of contention is that your previous posts suggest that 100% of scientists agree that mankind is causing global warming. I dont claim to be an expert in environmental matters but having worked with the EPA and being married to an environmental scientist I can attest there are many qualified folks arguing mankind's role in global warming is either tiny or nonexistent.

RE: Carbon Capture and Sequestration

Depends on your definition of qualified I guess

RE: Carbon Capture and Sequestration

3
Simply grow lots and lots and lots and lots and lots of trees, warehouse all of the wood/lumber in a way that it will not decay, and then when the CO2 levels start to swing back the other way and we start to realize that an ice age is imminent, start burning said wood. Simple. The trees could even be harvested the old fashioned way to prevent excess oil consumption by heavy machinery and trucks . . . axes bucksaws, ox carts, etc. The demand for flapjacks and bacon and flannel shirts will skyrocket, helping the farmers, it's win-win all the way around.


It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: Carbon Capture and Sequestration

The only way to haul wood any decent distance is with diesel trucks, though.

The alleged AGW is also contributing to drought conditions in many of the areas would have otherwise been ideal for tree planting, as well as resulting in a year-round fire season. A single season of fires results in the obliteration of years and square miles of tree growth.

However, in addition to drought, the "old-fashioned" way of tree harvesting was clear-cutting, which has resulted in many swaths of earth so eroded that they're no longer fit for trees or much of anything else.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Carbon Capture and Sequestration

That was somewhat a tongue-in-cheek post, but in theory it could perform the function necessary. No need to haul great distances if warehousing is the end game. Drought can most definitely be a factor, but there are still plenty of areas of the earth that see substantial rainfall and have soil conditions to support. We are seeing climate change, no doubt, and with that is coming climate shift. Areas that formerly supported forestation may no longer, and other areas, my locality included, are beginning to see wetter summers. Clear cutting is generally a terrible idea, agreed, but thinking of a fast growing species (poplars/alders, willow, etc) which reach harvestable maturity in 5 to 8 years, clear cutting and rotation becomes a do-able strategy. With woody biomass being roughly 50% carbon (dry) by weight, there is clearly some potential.

I still think reducing consumption is going to have to be the clincher, though. With the politics of maintaining a robust economy, this is unlikely to happen on a scale that is palatable to policy makers and the money kings.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: Carbon Capture and Sequestration

"With the politics of maintaining a robust economy"

I wish it were that simple in the US. There's certainly that school of thought, but there are others that simply want to reject that possibility outright, seemingly independent of whether there's some sort of short term benefit.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Carbon Capture and Sequestration

Quote:

Depends on your definition of qualified I guess
There's highly qualified folks on both sides of the issue. The challenge to arriving at a correct conclusion is that they're working on quite literally the world's largest engineering problem with an astronomical number of variables, in an open system, with inputs that still aren't well understood. Even our greatest minds can only work on one tiny part of the system yet are often asked to speak toward the entire system, hence why many will still run their mouth but are painfully ignorant of semi-common knowledge about air quality and current regulations.....bc they're an "authority."

The real challenge to reforestation is "overly concerned" politics, not global warming. In the US we do a piss-poor job of maintaining our forests for fear of upsetting the greenies. If you dont regularly cull the brush, dead, and diseased plants then you have the issues we do today with wildfires and poor plant health leading to high costs for even low quality lumber. My family's owned a sawmill in lower NY for a bit over 70 years and there's been a significant downward shift in forest health over the last few decades. Usually the difference between maintained and "protected" forests is visibly noticeable with the former being large, healthy trees producing good lumber vs the later which is only capable of producing junk firewood.

RE: Carbon Capture and Sequestration

The majority of photosynthesis occurs in the oceans from phytoplankton. Trees are insignificant. So this means we should use more fertilizer if we want to scavenge more carbon dioxide.

RE: Carbon Capture and Sequestration

You know if you put it all to gather, one of the best methods might well be growing apples in an orchard. The fruit would provide income to the caretakers. The wood used in making furniture of quality that people would want to keep for generations. And the leaves, mixed with other compost to keep the soil healthy.

I'm sure there are other examples, but the issue is managed, and income, as well as useful storage of carbon.

RE: Carbon Capture and Sequestration

"If you dont regularly cull the brush, dead, and diseased plants then you have the issues we do today with wildfires and poor plant health leading to high costs for even low quality lumber. "

One might want to recall that many of the trees, particularly in the Southwest and West, actually require fire to properly germinate. Moreover, no one wants to spend the money required to achieve the delicate balance needed for acceptable levels of brush fires that don't kill the trees. What has mostly complicated things now is that we're constantly building into the forests with homes that aren't completely fireproof.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: Carbon Capture and Sequestration

Quote:

Much as I like trees they are a con when it comes to carbon capture. They live for a few hundred years at most (and as a commercial venture more like 50) at which point all the CO2 they have sequestred is temporarily stored as wood or paper, or released immediately back into the atmosphere as it decomposes.

Do you have a source on how much carbon is re-released during decomposition? I'm not sure I believe your 100% claim.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

RE: Carbon Capture and Sequestration

You are right, some carbon is retained as organics in the soil, or indeed in the bodies of various organisms that feed on the rotting tree. Of course most wood I'm involved with goes up the chimney!

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 Capture and Sequestration

Why is carbon capture so important? And why is slowing the carbon cycle not the same thing?

Normal cycle, tree captures from the air. The tree lives so long, then dies. Dead trees release carbon into the air.
If you slow it down, like extending the time it takes to decay (as in the making of coal) such as building homes, or furniture of quality.

Another note is the people who are bringing up sunken trees from rivers, and finding the wood is in very good shape, as in very little decay.

RE: Carbon Capture and Sequestration

Does anyone know what the benefit would be if we could extinguish coal mine and coal seam fires?
I understand that just one can be large enough to emit as much greenhouse gases as all the cars in the US.
It seems that a concerted effort by the international community could put a significant dent in greenhouse gas.

Thanks,
Mark

RE: Carbon Capture and Sequestration

I like the idea of putting something up to block some of the sunlight. I saw a proposal for a diffraction grating that cost to 10 billion to set it up and make it and 10 billion extra to maintain it. Blocking a little bit of the light is probably easier than trying to fix our atmosphere.

------------------------------------------------------------------------------------------
If you can't explain it to a six year old, you don't understand it yourself.

RE: Carbon Capture and Sequestration

The clairvoyance of The Simpsons yet again comes to the forefront.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: Carbon Capture and Sequestration

The writing has been on the wall ever since we got to see the Hubble's pictures on where we stand in the universe, if you ask me. All this huffing and puffing about global warming is just a small manifestation of the utter hopelessness of our attempts to wrest some "progress" out of Nature (at its expense) for Man's sole benefit. We will never escape our near neighbourhood in space, unless some one can prove Einstein wrong very soon. If and when we get to Alpha Centauri (in about 300 000 years or so ?) and see the desolation there, we'll realise all we have is this precious blue planet we live on. Like it or not, we've got to recognize our biological limitations and take our place in Nature, turn out the lights and go back to the Stone Age in 10 000BC, and get back to worshipping trees, if we dont want to choke and drown in our own puke on this planet. More and more of the puke we generate these days has a half life of no less than 10 000years to boot, and a fair bit of it is blowing in the wind in the desert in Iraq. Pardon me for this rant, but I had to get this off my chest. Dont let this stop you from your quest to seek out economical ways to sequester CO2.

RE: Carbon Capture and Sequestration

Quote:

You are right, some carbon is retained as organics in the soil, or indeed in the bodies of various organisms that feed on the rotting tree.

Anybody here know the ratio?

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

RE: Carbon Capture and Sequestration

for the most part, creatures excrete about the same amount that they ingest, so machts nichts as far as carbon sequestration. Obviously, their offspring do grow up and assimilate nutrients. But, this article http://journals.plos.org/plosone/article?id=10.137... reports that insect biomass has decreased.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Carbon Capture and Sequestration

In the US, carbon sequestration is not practical, partly due to the fact that there are tens of thousands of abandoned oil and gas wells that were capped with a type of cement that eventually dissolves in the presence of carbolic acid, releasing the CO2 back to atmosphere. That acid would be formed if the CO2 were sequestered in areas drained by those wells. The main economic driver for carbon dioxide capture is for its ndustrial use , including tertiary oil recovery. In those cases, the CO2 is either directly leaked back to the atmosphere after its industrial use or would generate several times more CO2 when the recovered oil is later combusted.The idea that the CO2 is permanently sequestered is misleading and is used for public consumption. The current trend to use fracking to recover oil and gas would only worsen the rate of CO2 leakage from wells.

The most efficient process for CO2 capture is the Allam cycle, due to improvements in the cryogenic air liquifaction part of the cycle. If the demonstration project is successful, it would yet be more costly to build and less reliable than a conventional power cycle, due to the more complex configuration with many more opportunities for cycle components to fail.

The impact of anthropogenic combustion of carbon to CO2 is not the primary cause of recent warming, and those computer models that were used to justify that fear have been demonstrated to have exagerated the impact of CO2 on the tropospheric temperature by a factor of at least 3. In addition, those models did not properly consider the effect of clouds on the temperature of the lower atmosphere, which is another gross error of those models.

Recent work by Nir Shaviv and Henrik Svensmark demonstrates that a major cause of global climate change is the formation of clouds, and that rate of formation is related to available aerosols and their interaction with cosmic rays. Earth's exposure to cosmic rays changes based on the magnetic activity of the sun , and also the changing distance of the earht to the source of cosmic rays ( supernovas) over very long time periods . It is predicted that the current quiescence in sun magnetic activity will lead to global cooling over the next 20 yrs.

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

RE: Carbon Capture and Sequestration

If the solution is grow more trees, then you need more water. Consider the complaints of runoff on the Mississippi delta, which appears that the water needed is available in the middle of the country, and not in the West (general areas).
Another erosion factor is the wind in the middle of the country, which at one time was a concern of the USDA, which at one time recommended planting of trees around large planting areas.
That planting is no longer recommended, and since then prices for crops have dropped.

Just saying.

RE: Carbon Capture and Sequestration

Well to be fair, I believe the idea of planting more trees would probably include the condition of planting them in areas that can naturally sustain forest growth.

Andrew H.
www.mototribology.com

RE: Carbon Capture and Sequestration

cranky - I did some work a long time ago on water retention by trees in the catchment zones of reservoirs. It is pretty complex. Basically we were able to demonstrate to the inquiry's satisfaction that if the water authority chopped all the trees down then the water collected in the reservoirs would drop, because science. Now, to be honest that was the conclusion we wanted, I think if the water people had put their minds to it that they could have produced some valid counter arguments (I could). But the optics were terrible, as the politicians would say.

Cheers

Greg Locock


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RE: Carbon Capture and Sequestration

My point is that, while the west looks like more trees can be grown, the middle (area drained by the mississippi river) is a more likely area.
The problem is most of that area is farmland.

RE: Carbon Capture and Sequestration

In the US, modest scale reforestation has been proceeding for several years. The intent is not carbon capture / storage, but other benefits of reclaimed (former) forest land.
The program in the southeast that I'm familiar with is the Longleaf Pine Initiative.
The effort will never restore the historical 92 million acres of longleaf pine forest, but acreage has gone from 3 million acres a few years ago to over 4 million now.

For reference: In general, when engineers, and others, talk about "how good lumber was in the 19th century"... they are talking about longleaf pine.

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RE: Carbon Capture and Sequestration

Also known as southern yellow pine by us Yankees, and yes, it was very good lumber.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: Carbon Capture and Sequestration

My apologies cranky108, it seems I misunderstood your original statement.

My take on it, we can't take back what's been done. I think he best and most effective solution we can implement is to adapt, learn from our mistakes, and keep on moving forward. The earth will take care of itself one way or another. Much of the "help" people want to implement is more likely to cause harm than good. Moving forward as a species and trying to minimize our impact the first time around would be the best policy rather than trying to get the cat back into the bag.

Pie in the sky? Of course, but that doesn't mean it isn't worthwhile.

Andrew H.
www.mototribology.com

RE: Carbon Capture and Sequestration

There's a distinct difference between old growth and plantation/new growth lumber irrespective of species. My own house had true old-growth white pine trim, and the difference between that lumber and modern plantation white pine lumber is more significant than the difference between lumber from several different species of tree. Modern plantation white pine is barely denser than balsa wood and you can easily dent it with a thumbnail- you could break your thumbnail on my trim without denting it.

RE: Carbon Capture and Sequestration

'Modern plantation white pine is barely denser than balsa wood and you can easily dent it with a thumbnail-'

Maybe you should try oak trim. You can bend a nail with that. Or should I say a modern nail (modern cheep crap).

Modern things just don't seem to be as good as the old stuff.

RE: Carbon Capture and Sequestration

I use oak, ash, cherry, even a little maple- and only use white pine when I need to make something cheap- but that isn't my point. The point is that the old growth wood, with closely spaced growth rings, is much more dense and stable material. So much nicer to work with it's like it was a different species entirely.

RE: Carbon Capture and Sequestration

Growth rate does affect wood hardness, but the bigger thing is probably moisture content. When it dries out, it gets harder.

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