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Biochar/TerraPreta

post #1 of 29
Thread Starter 

what's your favourite Carbon sequestration scheme? (we are going to need more than one).

 

What I know, is soil. I have inadvertantly been adding charcoal from incomplete combustion form my woodburner ash to my compost raised beds for 15 years, and always marvelled at the continued fertility compared to bought compost. i had 10 year old compost that was still too fertile for decent seedling compost, where bought stuff was fine on the second year. also the bulk of the beds seemed to reduce only very slowly.

when i came on line 2 years ago, i found out about bio-char and terra preta experiments, and could immediately relate them to my experience. (might well be a bit of comfirmation bias there but whatever).

the theory is, the charcoal lasts for centuries, being a very stable form of carbon. it is also extremely porous, and once 'activated' holds nutrients, trace elements and minerals, and provides a good home for microorganisms, particularly funghi that sperad through the compost or soil and bulk it up with another long lasting carbon form from the mycelium sheath, as well as conecting the roots of plants and creating multiple symiotic relationships.

phew! thats the problem with trying to describe systems, its hard to start and even harder to stop. i'll try draw and post up a diagram when i have time.

 

links;

http://delicious.com/littlerobbergirl/biochar

 

 


Edited by gerda - Sat, 20 Dec 2008 13:57:29 GMT
post #2 of 29

Don't discount the minerals contained in the charcoal. I am doing a study on emissions from grain combustion.  The major elements in the ash from yesterday's sample were P 104000 ppm, Mg 107000 ppm, K 24500 ppm and Ca 22700 ppm. 

post #3 of 29

I don't know much about its benefits as a fertilizer, but I've always thought it was much more practical to sequester carbon in the form of charcoal than the gas itself. It just seems so much more efficient since charcoal can be up to 98% pure carbon, whereas the same weight of CO2 can never be more than 27% carbon.

 

Also, a solid would be easier to contain for obvious reasons than a gas. It could just be dumped into an old coal mine and sealed off with a lock and key, whereas with CO2 sequestration, the most feasible techniques proposed so far involve pumping it into abandoned oil wells or deep under the sea, with constant monitoring to make sure it stays air tight.

 

I really don't know why solid carbon sequestration doesn't get more attention...maybe someone else can answer that?

 

post #4 of 29
Thread Starter 
Quote:
Originally Posted by Whiteshell001:

Don't discount the minerals contained in the charcoal. I am doing a study on emissions from grain combustion.  The major elements in the ash from yesterday's sample were P 104000 ppm, Mg 107000 ppm, K 24500 ppm and Ca 22700 ppm. 

nice. how about trace elements? there are odd local shortages of things like boron. and i read this the other day;

"A team of researchers led by Princeton University scientists has found for the first time that tropical rainforests, a vital part of the Earth's ecosystem, rely on the rare trace element molybdenum to capture the nitrogen fertilizer needed to support their wildly productive growth."

 

and of course, the terra preta soils that set off the research in the first place are in the rainforest.

 

i used to make a 'hippy npk fertiliser' ; add a nights worth of pee (n) to the old washing up or wash water (p - from detergent)  throw in the ash from the burner (k), water pot plants with it. but i see from yr data that the washing up liquid was not essential. just as well, it didnt get added as often as the others lol!

 

dawei, just burying char would be a crime! it really does make a big difference to soil structure and fertility, warms it in the spring through making the soil lovely and dark, and also acts as a buffer, both ways.we use it to sweeten soil in pots, especially for bulbs (tip from my edwardian gardening books), and the wonderful dr. reddy of hydarabad is doing field experiments of bioremediation of salinated soils with it at the moment;

e-alkalinesoilsterrapreta.blogspot.com/

 

 


Edited by gerda - Sun, 21 Dec 2008 23:34:27 GMT
post #5 of 29

Trace elements are difficult to pin down because a small bit of dirt or stone can skew the results significantly. Most samples have Mo and B in the 1-10 ppm range, but occasioanlly the concentration goes to several hundred ppm. 

post #6 of 29

Plant nutrients will vary very significantly based on original soil and plant species.

One plant nutrient that will be lost is N.

Use of a pyrolitic process to give gas energy and charcoal is much more significant in lower lattitudes where loss of carbon from decomposing plant matter is very fast.

 

When you get as far south as Havana, (23 DEGREES N) the soil will contain only a tiny trace of carbon from decomposing plant material. Decomposition loses about 100%  of original carbon per year in low lattitudes. When we go to the Peace RIver country of Northern BC, plant material will decompose about 3% per year.

 

In southern Alberta it is up to 4%, and in southern Ontario as much as 5% per year. That more than doubles when we get to Cincinatti.

 

So, Canada north of 49th parallel  with minimum tillage does not benefit much by converting plant matter to charcoal. But close to Detroit we are starting to be concerned about warmer climate's effect on carbon retention.

 

Use of a pyrolitic process of course has a benefit of giving us some of the energy in the wood or other plant material, the gas released.

 

Because so much of the earth's soils would benefit from charcoal ammendment, we should prefer that to returning the plant matter directly to the soil.

 

When we have manure, with a high nitrogen content we need to extract the nitrogen fertilizer and most of the other plant nutrients by aqueous extraction before using the pyrolitic process. The nitrogen fertilizer if lost to the air represents an energy loss when we go about replacing that needed nitrogen.

We can extract the gas from manure  via methane production in a pit, and we can recover almost all the plant nutrient for crop use without any further loss of carbon. We do lose some carbon because the methane comes out mixed with a bit of CO2. It comes also mixed with ammonia that should be captured as fertilizer, but is likely to be captured as fuel along with the methane.

 

Yes, charcoal in soil will  act as a cation exchange capacity and this control escape of nitrate fertilizer. Now plant matter in compost does the same thing, but manure does not do as good a job, unless the manure is well laced with straw or sawdust. So composted manure with straw, sawdust, or charcoal will not burn crops it is applied  to. But that is entirely a function of the cation exchange capacity in the soil. Too little exchange capacity relative to the amount of nitrogen fertilizer present and we get burning of crops. We can also avoid burning of crops by carefully restricting the  amount of nitrogen fertilizer applied.

 

So soils with low cation exchange capacity, soils like sand, will benefit most from addition of charcoal, or plant matter  in soils far from the equator.

post #7 of 29

RE:

I really don't know why solid carbon sequestration doesn't get more attention...maybe someone else can answer that?

 

We still have a lot of greens who regard the burning of wood in any form as so environmentally harmful that even pyrolysis is going to be despised. For those individuals some form of conversion to alcohol is going to be preferred.

 

Now conversion to alcohol fuel avoids having that long list of harmful chemical pollutants relesed into the air.  We get CO2 from burning the alcohol, but do we get even the minerals from the substrate returned to the soil?

Well, with grain alcohol we have a food for animals, and again those animals release CO2 and methane, where the methane will eventually convert to CO2 and water, but we do have both mineral and nitrogen fertilizer from the end products. We have already removed most of the carbon from the original substrate before it makes it to the soil, so this material will do little to add tilth or cation exchange capacity to the soil.

 

So the main issue appears to be making sure that our pyrolitic process does not release any of those wood burning (smoke) chemicals. Offsetting this may be some efficiency in getting the energy from the substrate into the  fuel gas or alcohol.

 

But there is also an unmentioned opportunity to convert charcoal plus water into methane + CO2, just as coal and water will convert, or to CO2 directly.

So if we make this charcoal a commodity that people buy, they canuse  it much as one uses coal. It can even be used to smelt iron ore.

 

So, we have come full circle and instead of a great soil ammendment we have converted our substrate into CO2  plus a bit of ash.

 

post #8 of 29

GreenUpgrader just posted about Biochar a few days ago.


There’s probably no such thing as “clean coal,” but a form of charcoal could be of benefit to the environment, and help prevent global warming.


Biochar, first used hundreds of years ago to enrich soil in the Amazon, is a carbon-rich form of charcoal made from burning biological materials. Unlike regular charcoal, biochar is so resistant to degradation, it can be used to “sequester carbon in soils for hundreds to thousands of years,” according to research by Christoph Steiner of the University of Georgia.

 

(Read the rest)

post #9 of 29
Quote:
Originally Posted by donfletcher:

We still have a lot of greens who regard the burning of wood in any form as so environmentally harmful that even pyrolysis is going to be despised. For those individuals some form of conversion to alcohol is going to be preferred.

 

 

I sort of figured it was something like that. I guess it may also be the fact that it appears inefficient, since we're merely sequestering a solid that looks not much different from the one we took out of the ground in the first place. The natural reaction to something like that is for people to think "well lets just stop burning it in the first place", which obviously has not been a very effective idea so far.

 

Maybe sequestering the gas itself makes us *feel* like we're doing more, who knows. I just think solid sequestration would be so much more economical, and unlike gas sequestration it would hardly require any energy; just let the plant grow, set a match and bury it. Filtering it out of the air or from smokestacks is quite energy intensive.

 

As for the emissions from burning, shouldn't just a simple smokestack scrubber be able to cut down most of the bad chemicals? Yes there will still be ugly smoke, but if it's chemical free then its main effect should be to add aerosols to cool the planet...

 

post #10 of 29
Thread Starter 

yes stins, i noticed that came up on the sidebar when i added the climate change tag. thanks.

 

the thing is to try and get the best use from the feedstock. a closed system pyrolysis plant could be set up to produce a range of products; syngas to make various liquid fuels, heat, carbon dioxide (which in one of my heath-robinson systems diagrams would go into an algae farm next door with a bit of the heat, with the pressed algae residue going back into the burner with the wood and farm waste), and charcoal. tweak to adapt to local needs. the swedes are miles ahead on this.

post #11 of 29

I think that the best way to deal with carbon sequestration is to obviate the need for sequestration.  Digging up coal and replacing it with charcoal or biochar does not make much sense.  It makes more sense to just combust the charcoal completely as a replacement for coal.  The same carbon can cycle on an annual basis.  I think (hope) that the earth has enough buffering capacity left to mop up the excess carbon if human activities become carbon neutral.  I think that biochar is more significant for its effect on soil fertility than as a carbon sequestration medium.  To the extent that biochar improves soil fertility, there could be an amplifier effect with increased carbon sequestration due to higher biomass production. 

 

Gerda, the main problem with algae as a fuel for combustion is that most of the energy obtained goes into removing water.  Wet processes such as fermentation or anaerobic digestion to methane seem to be more feasible.  

post #12 of 29

We want to sequester biochar to get the plant growth capabilities it offers, rather than burning it to completion. Only when we have a deep rich soil all over the latitudes between N 35 and S 35 should we be burning the carbon to completion.

 

The bio-char has the potential to increase water retention, plant growth, CO2 capture, food production for centuries. This is one of the most effective uses of carbon.  Burning it to get energy has no residual benefit.

 

Burning wood,even with good scrubbing in the stack is not as clean as a good pyrolitic processor that feeds its fuel gases into a stack built like an oil refinery, removing almost every one of those chemicals and using them.

The pyrolitic process would return the bio-char as an important by-product.

 

If the fuel charge be surrounded with natural gas prior to heating in the pyrolitic oven we get almost no oxidation to CO2. but wood or other plant matter does contaon some oxygen and we will have some. Nothing like the  amount we would get from direct burning of the wood or whatever.

 

Plants from the oceans? There is a critical reason for removing excess plants from the oceans. We have large parts of the oceans that are lethal to all marine animal life because so much plant matter sinks into the ocean, decomposes and thus uses up all the available oxygen. This material if harvested would likely be pressed to remove most of its water because we do not want to transport 96 kg of water home to have 4 kg of mostly combustible material. Then when brought to land it will yield volumes of methane as it heats itself (spontaneous combustion being avoided by keeping oxygen away from it). The spontaneous heating will use up what oxygen is available and the plant matter will combust if exposed to air while hot.

It may be more economical to just let it burn. to produce steam power, but it can also be converted to bio-oil and bio-gas. Sea plants have a wondrous mixture of minerals that would be a bad idea to discard on land, most prominentof those being salt. Do we dare dump it at sea?

 

By the way, for those who want to stop the need to harvest  the ocean plants, there is a rumour that the ocean dead zones are created by having large emissions of phosphates from detergents and nitrates  from farm fertilizers. Not even close. The ocean creates all the nitrogen it needs via blue-green algae. But neither nitrogen fertilizer nor phosphate, Potash are ever deficient to grow just any amount of plant life in the oceans. All plant nutrients remain in the  water after the plant life decomposes. They just self recycle until they reach a concentration at which they start to precipitate. For example phosphate precipitates with calcium. The precipitation and redisolving maintain a level of phosphate that meets all plant needs. Excess phosphate entering the ocean simply hastens precipitation, as long as there is adequate calcium.

 

But lower calcium levels in the ocean do result in higher phosphate levels, higher CO2 levels, lower pH.

post #13 of 29
Thread Starter 

don, you do get local concentrations and deficiencies in oceans, that is obvious.

 

whiteshell, i agree that the main benefit of the char is to balance fertility, but the really interesting thing is how it aids micorhyyzal (aargh! no spellchecker!) growth, which in turn seems to boost non-labile carbon content.

post #14 of 29
Thread Starter 

well, my hero Lovelock has nominated biochar as the best last chance;

www.newscientist.com/article/mg20126921.500-one-last-chance-to-save-mankind.html


 

post #15 of 29

In a practical way, how do you turn a field of agricultural waste into biochar without consuming much energy.  Simply burning the field will not produce much char.  Is collecting residue and putting it in an oven cost effective?

post #16 of 29

It may be this will be a great thing for sequestering CO2 from the atmosphere, but making all this charcoal is going to put a lot (and I mean a lot) of light hydrocarbons into the air.  Those light hydrocarbons will get oxidized, and lead to killer smog episodes.  There are any number of studies around showing a link between biogenic hydrocarbons in the air and what is called secondary organic aerosol (meaning aerosols formed by products of atmospheric oxidation). 

 

http://www.atmos-chem-phys-discuss.net/9/3041/2009/acpd-9-3041-2009.pdf

 

http://www.atmos-chem-phys-discuss.net/9/2855/2009/acpd-9-2855-2009.pdf

 

http://www.atmos-chem-phys-discuss.net/9/2699/2009/acpd-9-2699-2009.pdf

 

(and that is just from one journal with papers that have been recently submitted)

 

I would be willing to wager several pitchers of beer that very large scale production of charcoal is going to lead to some very nasty side effects from an atmospheric chemistry perspective.  If this idea moves forward, you will hear the aerosol chemists start to weigh in, much as biological oceanpgraphers are starting to mumble loudly about how iron fertilization on large scales might not be such a good idea.

post #17 of 29

Although the slow effect of aerosols destroying people's health will be recognized over time,  the immediate cause of regulation is auto collisions deaths due to reduced visibility in the smoke.  Stubble burning is tightly regulated and discouraged in Manitoba. 

post #18 of 29
Thread Starter 

on a household or small farm scale, i agree, there will be the emissions from burning. but most of this burning would take place anyway, its a matter of getting more from your burn. its recently been found that the majority of the brown haze over asia is from buring of organic matter rather than fossil fuels.

 

for example, heating and cooking.

i burn wood in a burner for heat, by shutting it down tight last thing i get about 1kg of char a week with the ash, which goes on my plot.

many women cook on open fires, if rocket stoves are substituted, they use half the fuel and, due to the venting, the indoor air quality is dramatically improved. add a few refinements and you can also make some char as a byproduct. here's a whole forum of people designing and testing them.

 

bonfires.

many small farmers burn crop residue anyway. by going for a slow burn, as i was taught anyway for a garden bonfire, you retain more useful nutirents esp. potash, and get loads of fine char with the ash. heres a new article showing the proper old fashioned smouldering bonfire technique.

this includes slash and char rather than slash and burn.

 

on a large scale, pyrolysis plants should, and do, have the abatement one would expect in a modern setup.

 

 

post #19 of 29

*If* you are talking about this as a way to remove CO2 from the atmosphere, it will occur on scales that are huge.  Humans get "number numbness" but a biochar solution will have to produce gigatons of charcoal per year.  The conversion rate of biomass to charcoal is on average 60% (I think), meaning you will have to emit nearly as much light organics to the atmosphere as carbon you are planting in the ground.  I haven't done the math, but I suspect that adding gigatons of light hydrocarbons (we could assume it was going up as methane) to the troposphere might be a somewhat bad thing (i.e., change in oxidative capacity, greenhouse effect of the hydrocarbons themselves). 

 

Furthermore, you don't get something for nothing and sooner or later you have to have phosphate for plant growth.  Most phosphate fertilizer for large-scale agriculture is a mined resource, not renewable in the traditional sense, and takes energy to move it around.  Keep in mind you have to keep digging holes to bury the stuff, and find land that is available for digging new holes.  You have to transport it somewhere since you can't dig up cropland each year, put the biochar in a hole, fill it up, and then have enough time to get a crop planted.  There isn't enough time because you are talking about a vast amount of charcoal and dirt to be moved *EACH YEAR*.  Farmers are not going to go to all this effort without being heavily compensated, there will be huge shortages of manpower (Would you want your job to be digging holes all the time?  I know I wouldn't.) and I would be willing to bet there is a lot of agricultural waste that won't form charcoal easily on its own. 

 

Biochar may the truth light and way, but these are serious issues that will need to be addressed.  Any realistic solution to climate change has to start from the premise that in the future that at most we will all use perhaps 1/3 of the energy we now do.  There is no way for the planet to sustain our current lifestyles.  I have no idea how you go about cutting energy use per capita by that amount:  the situation may be essentially hopeless in terms of planned contraction of energy use and we'll see contraction through population decline rather than decreases in per capita use.  But I don't see "quick-fixes" like biochar, whose practicalities don't seem all that well thougth out to me, doing anything except trading one set of ridiculously complicated problems for a second set of ridiculously complicated problems. 

 

never post with a headache, it makes you cranky

post #20 of 29

An assumption that creating charcoal will cause release of  light organic hydrocarbons is partly based on the assumption that we would not be capturing those hydrocarbons and creating liquid and gaseous fuel with them.

 

The pyrolitic process does not release those hydrocarbons to any extent. They are channeled into a refinery comparable to what we use to refine oil.

 

Burning wood, or burning crop residues does release a lot of those hydrocarbons.

Your typical wood burning stove stovepipe will have 3 to 5 mm of creosote on the inner surfaces in one year if it does not get hot enough to cause achimney fire. But creosote is a small fraction of the hydrocarbons thrown off by burning wood.

 

Crop residue in Manitoba must not be burned. Many farmers will collect straw from the fields and leave it piled to decompose, because it makes it difficult to do tillage or seeding.  Net effect of this is that the extra step of converting the straw to charcoal, pyrolitically, and thereby extracting fuel gases would avoid having the straw decompose in a pile losing both the carbon and hydrocarbon to the air as CO2.

 

Now, the cost of transporting those straw bales to a distant processing plant would not be economic. So a microplant every few km comes to mind.

 

Incidentally, the city of Guelph, Ontario back when I was a child had a very large tank that collected the gases from a large pyrolitic oven, part of which gas condensed on the inside of the tank, part of which fed into the natural gas system. When originally built the liquid condensate was being transported to an oil refinery (during WW2) But the oil refinery stopped buying the condensate and the plant was shortly closed down. There was no emission of  hydrocarbons other than into the natural gas distribution lines.

 

Charcoal from that plant was being used as fuel, rather than as a soil ammendment. They were using garbage that made the charcoal non-usable for agriculture.

post #21 of 29

http://www.epa.gov/nrmrl/pubs/600r01011/600sr01011.pdf

 

http://www.agu.org/pubs/crossref/2001/2000JD000041.shtml

 

There are many many other such references.  There is also a great document by the UN FAO on charcoal production, which for some reason I can't find right now, discussing how the wood gas component carries only 10% of the energy of natural gas, making it unsuitable for co-generation of power.  They also point out that for proper production, the material must be dry, which seems to be a fairly large restriction on agricultural practices as far as crop harvesting is concerned. 

 

What you are arguing, is that many many small charcoal kilns will all be operated efficiently, that farmers will now spend a large part of their year loading bales of chaff into kilns, unloading the charcoal, digging holes, burying the charcoal, covering it, and do this year after year all the while making sure there are zero emissions from the kiln, that the residual toxics are collected and disposed of properly, while still performing all the usual tasks.  The scale this will have to happen on for it to have a meaningful impact on atmospheric CO2 levels will be enormous, figure you would have to bury the equivalent tonnage of charcoal per year that is mined as coal.  I find your proposition that this can be done with near zero secondary environmental effects absurd.  Simple issues like who is going to to all this menial labor are crucial, and as intractable as anything of a technical nature.  Will there be a new class of migrant workers, who come around in the fall, fire up the kilns, make the charcoal, bury it, and go away for the remaining 9 months out of the year?  Maybe, but having a huge body of manpower with nothing to do a large fraction of the year seems unwise to me. 

 

It baffles me why people think that there can be "business as usual" energy scenarios that are practical and will have any real hope of ameliorating climate change.  We are not going to solve the problem by shifting energy use around, nor by ill-posed schemes to sequester CO2. 

 

In his book Collapse, Jared Diamond cogently points out that technological solutions to environmental problems have historically been plagued by blowback.  The canonical example of this is the automobile, which saved cities from being inundated with horse manure but produced the environmental problems we are all too familiar with.  If we wish to avoid making the same sort of mistake, holding hands and singing about how great charcoal will be without carefully considering the issues I am raising is misguided at best. 

 

post #22 of 29
Thread Starter 

gcnp, what's all this digging holes business? you just spread it over the surface on a rotation.

 

loading up the village pyroliser shouldnt take more time than the extra work you would have to do to pay for artificial fertiliser ..... think more of the whole system rather than just one process.

 

as for phosphorous, we never used to have to mine it! we have it coming out of our bottoms in copious amounts. its another example of 'modern' inefficient straight line processes, rather than self contained loops. we send our phospates out to sea to make dead zones instead of putting it back on the land where it is wanted.

 

oh, and here is the house of a modern charcoal maker, what a hovel! and doesnt he look miserable.....

 

its one of many traditional jobs that go to make up mixed agrarian farming. 'subsistence' farming, as it is so often and so patronisingly called.

 

 


Edited by gerda - Sun, 01 Feb 2009 20:07:21 GMT
post #23 of 29
Quote:
Originally Posted by gcnp58:

The scale this will have to happen on for it to have a meaningful impact on atmospheric CO2 levels will be enormous, figure you would have to bury the equivalent tonnage of charcoal per year that is mined as coal.  

 

Not quite necessarily, if you factor in the increased growth rates and productivity that the biochar will give to the plants. Faster growing and bigger plants means more CO2 will be sucked out of the air. Of course the effect would probably be small, but if this stuff gets used on a massive enough scale it should be worth considering.

post #24 of 29

Personally, I could care less about the Stupid reply you make gnpc.

You have absolutely no interest in having the earth produce plant life, consume CO2, store water, or anything else.

 

You are in this only for immediate outputs of energy and immediate capture of CO2, with no concern for the hundred years to come.

 

You think because you read that technological solutions don't always work that therefore every thing you can construe as technological must fail? nonsense!

post #25 of 29

You all need to stop and consider how much mass of charcoal will be produced each year.  A gigaton of charcoal is a lot of charcoal.  You're not going to spread that much around each year on fields, even with rotation.  Arable land makes up about 12% of the world's surface, given that, and the need to sequester on order of 5 gigatons of carbon per year means you are talking on order of 1 kg/m^2 carbon needs to be produced and put into the soil (that is at least a couple of orders of magnitude larger than application levels of fertilizers).  That's around 10 metric tons per 100-m by 100-m patch, which is a huge amount of carbon to produce, cart around, and work into the soil.  The dust from such an operation would be incredible, and the radiative effect of soot in the atmosphere is orders of magnitude larger than any greenhouse gas. 

 

Aside from the fact that there seems to be a romantic notion that people will just naturally want to devote their lives to making charcoal and then carrying wheelbarrows of the stuff out into a field (which I don't see, personally), the collateral effects of producing that much carbon, by-products, and just moving it around will be huge.  If you want to talk sensible solutions to climate change, you need to start addressing issues like the ones I am raising, not just get mad at me for pointing out your "solution" is another example of that I call "the problem will be solved by us sitting around the campfire, holding hands, and singing Kumbayah."  I think there are serious issues with carbon sequestration by this method, nothing anyone has said here even remotely addresses the things I am concerned with.  I understand you're all ticked, but if you can't think about this under stress and come up with real answers for me, the idea is never going to survive when real skeptics get ahold of it. 

 

post #26 of 29
Thread Starter 

ok i checked this a few times on paper (billion and giga both mean 10^9 dont they)

 

from the f.a.o.;

 

"The total agricultural area in the world amounts to 5.0 billion ha. Of this, about 1.5 billion ha (30.4%) is arable land and land under permanent crops. A decreasing growth rate of 0.3% has been noted over the ten year period."

 

that's to 2004 but will do for order of magnitude.

 

so 5 x 10^9 tonnes x 10^3 / 1.5 x 10^9 Ha x 10^4

 

=1/3 kg per m squared.

 

totally a nice amount to bung on, my compost beds probably do get about half that over a winter and could easily take that much.


Edited by gerda - Mon, 09 Feb 2009 21:08:54 GMT

 

i am sorry if i came over a bit agressive, but i was pissed off with your not looking at the whole picture. it wont be just one solution, it will take every last little scrap we can throw at it. millions of small actions are not worthless.

 

you seem to be dismissing the idea out of hand. who ever said it had to be the only solution? it is one among many. restoring wetlands would be another, shellfish beds, making stuff out of wood and actually using said stuff for centuries instead of chucking after decades or years.

 

it goes without saying that these will only make a difference if we also reduce our emissions to hoefully zero. if we also do the ccs all well and good. some of us even think nuclear will be a nessecary part of the solution.

 


Edited by gerda - Mon, 09 Feb 2009 21:16:22 GMT

 

 

here are folk actually doing it on a small farm scale, in this case as bioremediation of alkali soils;

e-alkalinesoilsterrapreta.blogspot.com/

(start at the bottom)

 

dr. reddy has done a lot of research on terra preta and aslo designs hig-efficiency wood burners. this is people improving their lot and adressing sustainability at the same time. might seem a bit hippy dippy to some as it involves no machinery, no outside inputs, no money....


Edited by gerda - Mon, 09 Feb 2009 21:41:30 GMT
post #27 of 29

You're thinking that because your compost beds are managable then the scaling up to industrial levels will also be managable.  But that is where I think the problems will come into play.  You are internalizing a lot of the costs and energy associated with this so that the side-effects seem negligible to you, but when done on much larger scales they won't be.  Distributing tons of black carbon over loose soil will lead to increase black carbon aerosol in the atmosphere due to dust-blown aerosol generation.  That is not a good thing and you can't ignore it if you are suggesting doing this on global scales.  That's just a single problem.  If you can successfully generate 125 tons of charcoal using crop waste and distribute it over a 0.25 km^2 field using say 2-3 people, for 5 years running with no soil degradation or loss in agricultural productivity then you can claim it is a workable solution for a small farm. 

 

I am all for the "slice" approach to mitigating carbon emissions.  However, each slice should not be implemented unless the side effects have been carefully considered.  I have not seen any of the terra preta advocates really discuss things like what do you do with all the creosote, how exactly do you spread so much charcoal on fields, can fields take that much black carbon year in and year out, what will happen to concentration of heavy metals in the black carbon, where will the manpower required to do all this come from, and will this lead to elevated levels of atmospheric pollutants like black carbon. 

 

Adding charcoal to soil may be a great thing.  But I think there could be some nasty consequences and I don't see anyone advocating charcoal even remotely considering these issues except hand-waving assurances that "things will be fine."  I trust people lining up to make money off of remediating carbon no more than I trust oil companies lining up to make money selling oil.  People making money don't give a damn, in general, about side effects and just because a cause is considered "green" does not allow people advocating it to propose unsafe, unwise, and ill-posed methods as tried and proven. 

 

I got a fortune cookie once that said "Trust him, but keep your eyes open."  Everyone in the "green" business should take a hard look in the mirror and ask themselves if their eyes are really open. 

 

post #28 of 29
Quote:
Originally Posted by gcnp58:

 

I got a fortune cookie once that said "Trust him, but keep your eyes open."  Everyone in the "green" business should take a hard look in the mirror and ask themselves if their eyes are really open. 

 

GCC solutions are a great example of not putting all your eggs in one basket.  It can be as simple as making existing operations more efficient, or as challenging as developing ways to burn or sequester carbon that don't defeat the purpose and add to the problem at hand.  In the real world, a victory can be as simple as a winery becoming biodynamic rather than new wineries established that tear down oak woodland to satiate the appetite of wine connoisseurs and planting the variety de jour.

 

Everyone in the green business does not have their eyes wide open.  There's going to be a shakedown on this, and it's going to be hard to live through for some of us.  There will be mistakes made, lessons learned, and sometimes the cost of these mistakes will seem insurmountable.  But you compare notes, collaborate, and pick yourself up and do it again, better, differently.

 

Not sure why this dialogue appears to be a contentious one.  But I'm pretty sure it doesn't need to be, and that it shouldn't be, and that information and opinions can be shared by respecting the opinions of others and keeping your comments above board.

 

post #29 of 29

I hope this it will help you
“The Biochar Revolution” with “The Biochar Solution”

http://biochar-books.com/

It is a truly biochar Bible.

I believe this is the most beautiful holiday gift for your loved ones.

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