[Terrapreta] One Tonne of charcoal = X?? amount of sequestered GHGs

[Kevin Chisholm]

Dear Michael

Michael Bailes wrote:
> OK
> Given all the variables you have just been talking about.
> less need for fertiliser, greater crop, less transport etc
> etc etc
> 
> Can any one who is clever at sums, tell me how much GHG is sequestered per
> tonne of Charcoal?
> (Lets assume it is 99% pure charcoal or pick a number between 40-99%)
> This will be an important issue when carbon credits for Terra preta farming
> come in (as they must)

It is quite simple actually. One tonne of 100% Carbon in charcoal 
represents teh Carbon in one tonne of GHG.

Carbon and oxygen have molecular weights of 12 and 16 respectively; CO2 
is 44. 1 Tonne of pure Carbon would thus represent 1 x 44/12 = 3.66 
tonnes of CO2

I would think that typical charcoal would average about 93% Carbon, and 
7% ash. One tonne of this charcoal would thus contain Carbon equal to 
that containd in .93*3.66 = 3.4 tonnes of CO2

Best wishes,

Kevin
>