[Stoves] Project Drawdown

[Nikhil Desai]

Kathleen's blog is instructive:


"Since I normally blog about biochar, I would be remiss if I didn’t address
their coverage of biochar, which they rank as #72 with a drawdown potential
of .82 Gigatons of reduced CO2. The author of this section, like many
people, conflates the meaning of Terra Preta with biochar. While the two
are related,  they are not the same; the latter is but one element of the
former. They also state “*The preferred method is gasification, a higher
temperature pyrolysis that results in more completely carbonized biomass*.”
Gasification and pyrolysis are not the same; the former involves limited
oxygen while the later is a no oxygen thermochemical conversion process.
The two technologies can produce very different biochars, yields and
co-products and both can be done using high temperatures. They also say “*The
slower the burn, the more biochar*.” Generally speaking it is not the
duration of the burn but rather the temperature of the burn that impacts
yield the most (higher temps generate lower yield). There are other details
that show a lack of deep understanding of the nuances of biochar, which
could have easily been corrected had they reached out to one of many
biochar experts. While they do a decent overall job describing biochar
(albeit limiting it to a soils only perspective), what I think is really
unfortunate is the carbon math.  As I’ve already said the book is light on
details so it is impossible to understand the parameters for their
calculation of biochar’s drawdown potential, but I would guess they’ve only
looked at a limited type of biomass and then looked only at sequestration
capability and excluded the off-setting impact of other co-products (e.g.
renewable heat or electricity) or reduction of GHG impacts which varies
depending on the end use of the char (e.g. reduction of soil GHG emissions,
reduction of GHG related to fertilizer production, or CH4 from livestock
emissions if used as a feed additive)."

The book is likely to be "light", for popular reading rather than an
NRC/NAS report. But, despite the title and the quantitative targets, if it
nudges the discussion from bean-counters and techno-fixers and sees
interconnecting crises of the 21st Century (see a multi-agency report -
Social Dimensions of Climate Change, Draft 2012), that would be a huge
paradigmatic shift.

Nikhil







------------------------------------------------------------------------
Nikhil Desai
(US +1) 202 568 5831
*Skype: nikhildesai888*


On Thu, Aug 31, 2017 at 5:14 AM, Andrew Heggie <aj.heggie at gmail.com> wrote:

> On 30 August 2017 at 23:01, Paul Anderson <psanders at ilstu.edu> wrote:
> > To all, especially Anil, Ron, Nikhil, Andrew, and Jock,
> >
> > Andrew, Porject Drawdown certainly has a strong cookstoves component (and
> > char-producing TLUD stoves solidly links the stove and biochar components
> > that are being discussed.).
> >
> >
>
> Maybeso in much the same way stoves are used to cook food but we don't
> generally discuss recipes as there are plenty of cooking sites for
> that, as there are many more suitable places to discuss biochar, and
> geo engineering.
>
> As an aside I was amused by his reference to the cost of transporting
> of bodies around by aeroplanes when it was only ideas that needed
> discussing which could be done in virtual reality.
>
> Andrew
>
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