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bio-char and sequestering carbon

quarky

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Reading about bio-char and carbon credits has me wondering about some slippery slopes ahead. Although bio-char is potentially a soil amendment, and plastic is not, wouldn't burying plastic also sequester carbon?
 
quarky said:
Reading about bio-char and carbon credits has me wondering about some slippery slopes ahead. Although bio-char is potentially a soil amendment, and plastic is not, wouldn't burying plastic also sequester carbon?
Click to expand...
I think plastic storage would prevent the carbon in that plastic being released into the atmosphere but that plastic came from oil. The idea of sequestration is to take carbon from the CO2 in the atmosphere and make that unavailable, so creating a means of actively removing carbon from the atmosphere.
Photosynthesis makes use of the atmospheric CO2 but its products are, generally speaking, food for something or other and so, ultimately, ends up back in the atmosphere. Somehow that carbon must be fixed and made unavailable.
The charring process carbonizes most organic material makes them biologically unavailable; so the charred plant material is sequestered carbon from the atmosphere. At the same time, the charring process breaks down the structure of plant cells and makes chemical elements, like nitrogen and phosphate, available as fertilizers. Hence, biocharring kills two birds with one stone.
So the theory goes, I don't know how well it works.
 
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Sure burying plastic which is effectively putting fossil carbon back in the ground works but bio-char can enhance soil productivity as well as sequester.

a Two fer as extra plant growth pulls carbon out as well.
 
The char isn't sequestering carbon from the atmosphere...its using bio-mass that has already done that, releasing some CO2 in the process.
As I understand it, the char isn't a soil nutrient; its a potential home for bacteria and fungi, which enable fertility. Possibly, plastic could do likewise.
 
quarky said:
The char isn't sequestering carbon from the atmosphere...its using bio-mass that has already done that, releasing some CO2 in the process.
As I understand it, the char isn't a soil nutrient; its a potential home for bacteria and fungi, which enable fertility. Possibly, plastic could do likewise.
Click to expand...
The biomass is sequestered atmospheric CO2, that is true, but it remains a natural material and is still metabolically available to and usable by microorganisms; hence, it is rapidly returned to the atmosphere. Biochar is not a natural material and is not metabolically usable by microorganisms; hence it will become a long term component of the soil - and will be permanently, or at least semi-permanently, sequestered from the atmosphere.
As you say, the hope is that it will also be a good physical environment within which a soil ecosystem might flourish.
 
Bio-char is useful as a means of sequestering carbon because it is relatively inert, and not prone to uptake in plant metabolism. Its role as a positive influence in soil fertility, as I understand it, is merely through it's unique structural nature, and its enormous surface area, which can be inoculated with micro-organisms .

I guess what I'm wondering is this:

Could buried plastics be engineered to also provide this vast surface area/volume ratio?
If so, would it be perverse to recycle plastics?
Because they could do more good if they were buried?

In the bio-char angle of sequestering, which claims positive effects on soil fertility, and the ensuing growth of green plants, couldn't certain plastics make the same claim? Being as the char is merely providing a surface for bacterium and fungi, and specifically no nutrients?


While I'm on the subject, I've been a bit conflicted as per the role of clams and mussels and barnacles and such...

their shells are mostly Ca(CO3)2 and the carbon part of that equation may come from the ocean, or it may come from the sky...some debate on the matter...yet, even if it comes from the water, it enables the ocean to absorb more CO2.
Hence, encouraged clam growth sequesters carbon. Shells last as long as char, if you heap them up in the right place.

Cutting to the chase:

In the economics of carbon sequestering, combined with a touch of good will and community service, why not gather up massive amounts of harmful plastic flotsam in the ocean; ensnared in more plastic; perhaps plastic drift nets; and allow (and encourage) an encrustation of barnacles on that heap; protecting the plastic crap from the devastation of the sun's rays; providing surface area in otherwise desert-like ocean areas; possibly to the point of creating artificial floating islands, capable of supporting green plants on top?

For the purist capitalists, said 'islands' might also provide prime real-estate.
Coral reefs could be created by suspending substrate from the floating islands; near the perimeter, so that sunlight would reach the artificial reefs.

Such an approach is far-fetched, yes...
Yet, one might claim carbon credits to off-set the initial costs; as well as any clean-up incentives available...plus the creation of fabulous habitat for humans.

I've been reading up on various projects that reclaim the desserts on Earth; a noble enterprise. Yet, the flat oceans have dead spots too...dead zones with awesome solar energy potential.

Given the right site, said island of garbage might be able to achieve economic viability through the desalinization of sea water and the sale of potable H2O.


Have i gone too 'utopian' in my query here?
Or might I have a valid idea for part of the future?

Thanks for listening.
 
I'll let you do the math

5.50 metric tons CO2e for the average passenger vehicle (1.50 metric tons CE)
per vehicle


Just the vehicles produced in a given year

70 million

600 million in service.

=

3 billion metric tons of C02
or about 1 billion of CE

So to offset that with sequestering in any form you first have to get the carbon into some sort of storable format.
That requires energy...and density.

Anyone care to calculate how big a volume 1 metric ton of liquid C02 represents.

and the energy to get it there. :boggled:
 
There is a different sort of sequestering; not burning that stack of tires, for instance.
Intercepting carbon that is about to go into the atmosphere should be worth something, as per the economics of carbon credits.
 
Making concrete is sort-of neutral, minus the energy required to drive off the CO2 from the Ca(CO3)2

It does take it up again, in effect forming artificial limestone.
 
Concrete can also be designed to have quite high uptake and since it has to be made anyway reusing plastics etc from landfills in the kilns is a good approach.

Cement from CO2: A Concrete Cure for Global Warming?
A new technique could turn cement from a source of climate changing greenhouse gases into a way to remove them from the air
By David Biello | August 7, 2008 | 60
Click to expand...

http://www.scientificamerican.com/article.cfm?id=cement-from-carbon-dioxide

snip

It's a twist that could make a polluting substance into a way to reduce greenhouse gases. Cement, which is mostly commonly composed of calcium silicates, requires heating limestone and other ingredients to 2,640 degrees F (1,450 degrees C) by burning fossil fuels and is the third largest source of greenhouse gas pollution in the U.S., according to the U.S. Environmental Protection Agency. Making one ton of cement results in the emission of roughly one ton of CO2—and in some cases much more.

While Calera's process of making calcium carbonate cement wouldn't eliminate all CO2 emissions, it would reverse that equation. "For every ton of cement we make, we are sequestering half a ton of CO2," says crystallographer Brent Constantz, founder of Calera. "We probably have the best carbon capture and storage technique there is by a long shot."
Click to expand...
 
thanks, macdoc.

Great links.
I've also heard of bricks that somehow sequester carbon.
Though I know some stuff about cement, this technology escapes me.
I will read up.
 
quarky said:
Reading about bio-char and carbon credits has me wondering about some slippery slopes ahead. Although bio-char is potentially a soil amendment, and plastic is not, wouldn't burying plastic also sequester carbon?
Click to expand...

More effectively than biochar, but bio-char provides benefit when used as a soil amendment, plastic does not.

I would prefer to cut down on the oil to produce new plastic and encourage recycling of plastic.
 
quarky said:
There is a different sort of sequestering; not burning that stack of tires, for instance.
Intercepting carbon that is about to go into the atmosphere should be worth something, as per the economics of carbon credits.
Click to expand...

Cap and trade credit issues are hopefully dead.

A Carbon tax makes much more sense given the goal and nature of the problem.
 
TShaitanaku said:
More effectively than biochar, but bio-char provides benefit when used as a soil amendment, plastic does not.

I would prefer to cut down on the oil to produce new plastic and encourage recycling of plastic.
Click to expand...

Me too. Meanwhile, there's mountains of plastic crap almost everywhere.
Why not sequester it?
As a soil amendment, afaik, bio-char simply supplies a surface for micro-organisms.
Is it possible that plastic would also do that?
 
Gee, maybe banning yard waste from landfills because of innumerate leftover '70s ranting about running out of room for trash wasn't such a bright idea after all.
 
quarky said:
Me too. Meanwhile, there's mountains of plastic crap almost everywhere.
Why not sequester it?
As a soil amendment, afaik, bio-char simply supplies a surface for micro-organisms.
Is it possible that plastic would also do that?
Click to expand...

Plastic suitable to soil amendment would have to be processed, requiring additional energy input and expense. Burying it or converting it to foam-soil means you still need to find an new feed stock to make the new plastic. While mining sequestered carbon to make plastics it better than burning it, it creates more problems than it resolves, by creating a continuing market for sequestered carbon mining. Petroleum and coal need to go the way of ambergris and whale-oleum.

Potential additional problems with plastic soil amendment is described in these Royal Society Studies published in mid 2009 (in fact, it comes from a Royal Society theme issue on "Plastics, the environment and human health"):

"Accumulation and fragmentation of plastic debris in global environments" - http://rstb.royalsocietypublishing.org/content/364/1526/1985.full

"Plastics, the environment and human health: current consensus and future trends" - http://rstb.royalsocietypublishing.org/content/364/1526/2153.full
 
BTW, the concrete is what doomed the biosphere-2 experiment. It sucked up their atmosphere. But I don't think you could make much of an impact with it globally because we keep blowing up mountain ranges to get at thin seams of coal within so we can burn it.
 
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