Reducing CO2 Emissions by Pyrolysis

Source: Science Daily

When bioenergy is produced by pyrolysis (low-temperature burning without oxygen), it produces biochar, which has twice as much carbon in its residue than that from other sources. This makes bioenergy carbon-negative and improves soil health.

This process, he writes, would double the carbon concentration in the residue, which could be returned to the soil as a carbon sink. The exhaust gases from this process and other biofuel production could then be converted into energy.

This so-called biochar sequestration could offset about 10 percent of the annual U.S. fossil-fuel emissions in any of several scenarios, says Johannes Lehmann, associate professor of soil biogeochemistry in the Department of Crop and Soil Sciences at Cornell.

if i'm not mistaken, the technique relies heavily on carbon trading in order to be profitable, which in itself leaves a sour taste, imho, but the inherent advantage of producing fertilzer as a 'waste' product can't be denied. more iportantly, it seems as if pretty much anything biological could be used as feedstock:

Compared with ethanol production, pyrolysis that produces biochar and bioenergy from its exhaust gases is much less expensive, Lehmann said, when the feedstock is animal waste, clean municipal waste or forest residues collected for fire prevention.

if it's more cost efficient than f-ex. bio-ethanol, relies on waste products as feedstocks, gives fertilzer in return AND reduces net carbon dioxide emissions, it's probably worth pursuing, as long as subsidies remain a transient phenomenon, of course.

Hmm, interesting. I wonder if Algae is compatible with this method, though I think the byproducts of that technology(should it ever get off the ground) will go towards Biofuel mostly.

I have also heard that the exact reverse might be a good way of making emission scrubbing much more efficient. That is, instead of burning a Coal fire in regular Air, you replace it with a pure Oxygen environment. IIRC, the Pure O2 environment reduces the NoX emissions by almost 100%. This is due to the lack of Nitrogen in the combustion chamber. The idea being that Water Vapor is easier to remove from the mostly CO2 and CO emissions left over.

[edit on 13-5-2007 by sardion2000]

the idea has a big drawback: isolating oxygen in vast amounts sounds energy-intensive, doesn't it?

feeding highly concentrated CO2 to algae farms sounds good too, as long as sufficient exposure to sunlight can be arranged. artifical lighting does not cut it, for obvious reasons.