[Terrapreta] Flaring the more potent GHG in the off gas from a charcoal kiln?

[code suidae]

On 6/2/07, Sean K. Barry <sean.barry at juno.com> wrote:
>
> So, producing any type of charcoal and NOT FLARING the off gas is bad!
> The effect of releasing the only ~2%-CH4 into the atmosphere as a green
> house gas does go down over time,  but it isn't offset by the reduction in
> atmospheric carbon that was achieved by burying the charcoal in the soil
> (for at least the first 100+ years anyway).  It definitely would be creating
> another problem to NOT flare off the the ~2%-CH4.
>
> However charcoal is produced, the off gas from the kiln must be "flared
> off".
>

I cannot imagine a large commercial charcoal production operation would not
take advantage of the energy available in the flare gases. Rather than waste
this energy it could be used, for example, in ethanol or biodiesel
production, thereby offsetting the use of fossil fuels that would have
otherwise been used for this purpose.

I think it could also be argued that since the end product of the process is
intended to increase the productivity of the soil one would have to factor
in the temporary but long term increase in biomass carried by the soil
produced with the char. That is, the increase in biomass that results from
soil improvement represents sequestered carbon and should be included in the
accounting.

Likewise, If char-improved soil were in service as commercial farmland the
increased productivity may result in reduced consumption of fossil fuel
based fertilizer and the GHGs that would otherwise have been produced. These
offsets are a direct result of the production of the char and so should also
be considered.

These factors are difficult to calculate but it seems to me that if the
primary goal is sustainability than it is a bit perverse to only consider
the immediate first-order impacts of production.

DOK
-- 
"Our ignorance is not so vast as our failure to use what we know." - M. King
Hubbert
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