[Terrapreta] energy balance and emissions

[Ron Larson]

Mariska:

    1.  Good question below.  There is no doubt that there is plenty of exothermic energy release during pyrolysis (we ususally hear of a starting biomass energy content about 18 MJ per kg and with about 25% by weight charcoal left over at 30 MJ per kg (or 7.5 MJ in 250 gm) - there was about 10 MJ per kg available for productive use.  However, if none is captured for productive use (cooking etc) and one places about half of the initial carbon (and energy) into the ground - one is justified in asking about net energy balance.

   2.  However, even then, I believe one can show (eventually - haven't seen it yet -  in the published literature) that the later increased productivity of the soil and the need for less fertilizer will again show an even bigger positive net energy benefit.

   3.  Great that you are working on this problem.

Ron
  ----- Original Message ----- 
  From: mariska evelein 
  To: terrapreta at bioenergylists.org 
  Sent: Tuesday, November 13, 2007 7:35 AM
  Subject: [Terrapreta] energy balance and emissions


  Hello

  Sorry if this has come up before, I'm quite new on this list and haven't seen this discussed before.

  I'm doing some research into the benefits and draw backs of biochar production on a large scale,
  which has led me into looking at the energy use and emissions of the production process.

  Has anyone found any publications or other information covering this, I have pretty much exhausted the www and available literature on pyrolysis - but they are all evading this issue.

  I'm assuming that the energy balance of the production is positive - ie some energy will be produced in the exothermic stage which will make up for the energy used to set the process off - but I want to find some hard numbers.


  Any info is helpful
  Thanks
  Mariska


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