[Stoves] [biochar-production] Re: Stoves Digest, Vol 14, Issue 17

[Crispin Pemberton-Pigott]

Dear Frank

Apart from the special case of rice hull, how could you get a 50% ash level in char?  Trees are about 0.5% ash. There is not much left of the fuel if the char is 1% of the initial mass. 

Regards
Crispin

Frank,
 
I see the ash/carbon content as a sliding scale with relative changing benefits rather than a threshold level. If biochar has less carbon than ash is there still an agronomic benefit?
 
It is not clear how the IBI guidelines will be used. The guidelines should list those components that should be measured. The recommended levels of those components for different purposes could be separate recommendations from IBI to a certification agency.
 
If the purpose is stability and carbon sequestration why limit counting recalcitrant carbon even if it is 0.1% carbon or, 99.9% ash?
 
Tom