[Stoves] on evaluating the performance of a stove

[Paul Olivier]

Ron Larson sent me an interesting link:
http://www.vrac.iastate.edu/ethos/files/ethos2012/SatAM/Panel/Mitchell_IWA:ISO.pdf

In this presentation, please see page 3 where mention is made of the
Multiple Health and *Broader Impacts* of Household Energy. Note that there
is a block diagram on the Environment. A distinction is made between local
and global. Under local, mention is made of deforestation, erosion and
desertification, and under global, mention is made of black carbon and *other
greenhouse gas emissions*. No doubt CO2 is considered a greenhouse gas by
the author of this presentation. On page 13, of the Lima Consensus, mention
is made of tier 3 stoves that stretch goals which achieve significant,
measurable health *and/or environmental goals*. On page 15, under Climate
Impact the question is posed: what affect will the stove have on local
and *global
environment*? On page 16, mention is made of Tier 4 stoves that target
ambitious health and *environmental* outcomes.

A stove should be rated on what it is designed to burn. If a stove does not
burn biochar, biochar should be left out of the equation used in
determining its efficiency. Biochar is not part of the fuel that powers
biochar-making stoves, and the production of biochar is not a residue left
behind that has a negative environmental impact. The fuel that powers a
biochar-making stoves is the  syngas that it produces. Syngas is the fuel -
not biomass.

The same logic applies to some fossil fuel gas stoves. In many cases we do
not judge their efficiency starting from the chemical composition of the
fuel that came out of the ground. Before some fossil fuels can be used as a
fuel, they have to be refined and cracked, and all of this processing
translates into an inefficiency that has to be taken into account as gas is
burned in a kitchen. The refining and cracking of many fossil fuel gases
takes place outside of the kitchen. By contrast a biochar-making stove does
the refining and cracking and burning of the gas all within the one process
- while a meal is being cooked.

Unlike some fossil fuel gas stoves where the refining and cracking of the
gas take place at a refinery outside the kitchen, the gas that my
biochar-making stove produces is not allowed to cool down before it is
burned. I measured the temperature of the hot syngas from my stove, and at
the beginning of a burn, it reached a temperature greater than 500 C. The
efficiency of a gas stove should also be measured in terms of the
efficiency of what goes into preparing the gas that it consumes.

Note that there are some Chinese low-temperature pyrolysis stoves that,
unlike my stove, filter and cool down the gas before it is routed to a
burner. The pyrolysis unit is situated outdoors, while the burner is
situated in the kitchen. All of this should be taken into account when
judging the efficiency of such a stove. In judging the efficiency of a
stove, we cannot limit our analysis to only what happens in a kitchen.

Biochar is a precious resource that has advantages far beyond the energy it
contains. Its contribution to the reduction of greenhouse gas emissions is
significant, and yet this is not explicitly taken into consideration in
evaluating Tier 4 stoves that target ambitious environmental outcomes.
Perhaps something is missing here.

Where I live in Vietnam (Dalat), there are thousands of greenhouses within
and around the city. The people who operate these greenhouses know why they
put rice hull biochar into their potting soil mixes. They do so because
biochar  increases plant growth and reduces water and fertilizer
consumption. All of this should impact ambitious environmental outcomes of
Tier 4 stoves.

Thanks.
Paul Olivier


-- 
Paul A. Olivier PhD
26/5 Phu Dong Thien Vuong
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130813/6d532fdc/attachment.html>