4 ms·

The Case for Burying Charcoal (2007)

14 points by mmphosis 17y ago

paul 17y ago
If only we could somehow bury coal...
furyg3 17y ago
Unlike coal, biomass is carbon-neutral, releasing only the carbon dioxide that the plants had absorbed in the first place. Um... What? Coal is also "releasing only the carbon dioxide that plants had absorbed in the first place". It's a question of time. If you're burning biomass faster than you're producing it, it's not carbon-neutral.
camccann 17y ago
Aside from the carbon sequestration aspect, "burying" charred biomass is very interesting from a standpoint of improving soil quality, as mentioned briefly in the article--though it's not really burying so much as churning it into the topsoil. As an illustration, it's now known that the rich, fertile soils of the Amazon river basin are actually man-made, via a process of soil enrichment thought to involve burying smoldering wood to create charcoal, then breaking the char up and mixing it into the soil along with manure and other organic waste. The natural soil of the Amazon is actually very poor and infertile otherwise! See also: http://news.ycombinator.com/item?id=934117 http://news.ycombinator.com/item?id=934117 (I commented there as well along similar lines) Related articles on Wikipedia: http://en.wikipedia.org/wiki/Terra_preta http://en.wikipedia.org/wiki/Terra_preta http://en.wikipedia.org/wiki/Biochar http://en.wikipedia.org/wiki/Biochar
- jurjenh 17y ago
  I read the same articles, and this does seem to have potential in multiple fields - reducing carbon emissions, potentially increasing soil quality and hence crop yields (although I do believe this is specific to certain types of soil) - which may indirectly reduce the requirement for some types of fertilizer. And one of the amazing things of the "terra preta" of the amazon is that it seems to regenerate itself - unlike modern fertilizing which is generally required annually - this may indeed make it a disruptive technology from ~2500 years ago!
jurjenh 17y ago
Having just re-read the article, I can only come to the conclusion that it has editorial spin - I can't see how this can possibly reduce CO2 emissions, unless the charring releases enough useful fuel to supplant the original heat required, which is not stated anywhere. To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or burying it does not require this fuel, hence the CO2 "savings" are even greater. To do all this to sequester carbon seems to be missing the point, and we'd all be better off by not burning anything in the first place. What may prove to be useful is the extraction of other products, and the potential soil benefits. If a compelling case can be made for these alone, then it might indeed be useful. The carbon sequestration / global warming aspects seem to only be adding political spin to the issue.
- camccann 17y ago
  To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or burying it does not require this fuel, hence the CO2 "savings" are even greater. To do all this to sequester carbon seems to be missing the point, and we'd all be better off by not burning anything in the first place. Well, organic matter normally releases carbon when it decays, so just leaving it as-is would be carbon neutral, liberating the carbon the plant originally drew from the air to grow. On the other hand, the pyrolysis process requires energy, yes, but releases very little carbon from the material being processed. The resulting carbon-rich biochar doesn't rot, so the carbon isn't released back into the atmosphere but remains in the soil, while new plants grow in place of the old ones, pulling more carbon from the air. The claim in the article, presumably, is that the carbon output associated with the energy to heat the biomass is less than the amount of inert carbon added to the soil, making the entire process effectively remove carbon from the atmosphere. Highly doubtful that the amount of carbon thus extracted would be significant, though. The soil improvement aspect is far more interesting to my mind, the carbon stuff is probably just a way to get more attention.
- yummyfajitas 17y ago
  I believe the premise is that we could reduce CO2 emissions if we substituted biochar for coal in energy production. However, I'm having a hard time making sense of their numbers...

14 points by mmphosis 17y ago

paul 17y ago

If only we could somehow bury coal...

Unlike coal, biomass is carbon-neutral, releasing only the carbon dioxide that the plants had absorbed in the first place. Um... What? Coal is also "releasing only the carbon dioxide that plants had absorbed in the first place". It's a question of time. If you're burning biomass faster than you're producing it, it's not carbon-neutral.

camccann 17y ago

Aside from the carbon sequestration aspect, "burying" charred biomass is very interesting from a standpoint of improving soil quality, as mentioned briefly in the article--though it's not really burying so much as churning it into the topsoil. As an illustration, it's now known that the rich, fertile soils of the Amazon river basin are actually man-made, via a process of soil enrichment thought to involve burying smoldering wood to create charcoal, then breaking the char up and mixing it into the soil along with manure and other organic waste. The natural soil of the Amazon is actually very poor and infertile otherwise! See also: http://news.ycombinator.com/item?id=934117 http://news.ycombinator.com/item?id=934117 (I commented there as well along similar lines) Related articles on Wikipedia: http://en.wikipedia.org/wiki/Terra_preta http://en.wikipedia.org/wiki/Terra_preta http://en.wikipedia.org/wiki/Biochar http://en.wikipedia.org/wiki/Biochar

jurjenh 17y ago
I read the same articles, and this does seem to have potential in multiple fields - reducing carbon emissions, potentially increasing soil quality and hence crop yields (although I do believe this is specific to certain types of soil) - which may indirectly reduce the requirement for some types of fertilizer. And one of the amazing things of the "terra preta" of the amazon is that it seems to regenerate itself - unlike modern fertilizing which is generally required annually - this may indeed make it a disruptive technology from ~2500 years ago!

jurjenh 17y ago

Having just re-read the article, I can only come to the conclusion that it has editorial spin - I can't see how this can possibly reduce CO2 emissions, unless the charring releases enough useful fuel to supplant the original heat required, which is not stated anywhere. To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or burying it does not require this fuel, hence the CO2 "savings" are even greater. To do all this to sequester carbon seems to be missing the point, and we'd all be better off by not burning anything in the first place. What may prove to be useful is the extraction of other products, and the potential soil benefits. If a compelling case can be made for these alone, then it might indeed be useful. The carbon sequestration / global warming aspects seem to only be adding political spin to the issue.

camccann 17y ago
To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or burying it does not require this fuel, hence the CO2 "savings" are even greater. To do all this to sequester carbon seems to be missing the point, and we'd all be better off by not burning anything in the first place. Well, organic matter normally releases carbon when it decays, so just leaving it as-is would be carbon neutral, liberating the carbon the plant originally drew from the air to grow. On the other hand, the pyrolysis process requires energy, yes, but releases very little carbon from the material being processed. The resulting carbon-rich biochar doesn't rot, so the carbon isn't released back into the atmosphere but remains in the soil, while new plants grow in place of the old ones, pulling more carbon from the air. The claim in the article, presumably, is that the carbon output associated with the energy to heat the biomass is less than the amount of inert carbon added to the soil, making the entire process effectively remove carbon from the atmosphere. Highly doubtful that the amount of carbon thus extracted would be significant, though. The soil improvement aspect is far more interesting to my mind, the carbon stuff is probably just a way to get more attention.
yummyfajitas 17y ago
I believe the premise is that we could reduce CO2 emissions if we substituted biochar for coal in energy production. However, I'm having a hard time making sense of their numbers...