[Stoves] Comments about T-LUDs

[Roger Samson]

Paul 


If we do get into a runaway greenhouse effect, I think that this whole
concept of using plants for energy and recovering their carbonized residues
for soil carbon restoration is one of the best large scale options we have
for stopping the greenhouse effect. In North America alone we can produce 1
billion tonnes of biomass. 

Check my calculations here, let's say roughly a tonne of biomass contains
45% carbon, and 12% of that C is not released in a t-Lud process and left as
a carbonized product and sequestered in soils. 

If we used 2 billion tonnes of biomass globally in this process (for energy
and soil improvement applications in both developing and industrialized
countries), we would have roughly 240 million tonnes of C conserved or
converted to C02 (x 44/12)= 880 million tonnes of C02 stored annually and
rid the world of a lot of coal, kerosene, propane and natural gas. You could
also get roughly 2 billion tonnes of C02 avoided if 100% of the applications
were displacing fossil fuels or about 1.5 billion tonnes of CO2 avoided in
greenhouse gases from a 50-50 displacement of fossil fuels and fuelwood (non
CO2 GHG's avoided from incomplete combustion processes) . 

In an ideal world where the CDM process was actually working to effectively
help small scale energy projects the whole thing would have very strong
financials. I think the whole thing is viable if we could get this into a
CDM process and carbon credits remain at their present level of 16
euros/tonne or $20/tonne of CO2 displaced. However, we need to fix the CDM
process because it's not working for small scale renewable energy projects
the way it should be.  

This is so much cheaper an option than carbon capture of C02 from fossil
fuel combustion using pipelines etc. As we know that agricultural commodity
prices have declined in real dollars for the last 600 years, its going to
become more and more viable. AT $60 barrel oil and $20/tonne carbon credits
the bioheat industry can gobble up a large market share of the fossil fuel
industry currently used in heat related energy applications like cooking,
industrial processes and commercial heating applications. They will be
forced to drop their prices to stay competitive. It will delay the
extraction of the fossil energy dowry of the world and prevent much of it
from becoming economically recoverable.   


Roger Samson

www.reap-canada.com



-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of Paul S. Anderson
Sent: Thursday, September 28, 2006 9:49 PM
To: adkarve
Cc: stoves at listserv.repp.org
Subject: Re: [Stoves] Comments about T-LUDs

Dear A.D., Roger and all,

Interesting that both of you responded in terms of the fuels, but from 
different
perspectives.  Both mention the issue of the residual charcoal, so I 
start from
that point.

1.  It is OPTIONAL to save the charcoal, and AD makes a good case to do so
in
India, and Roger mentions the benefits for the soils.  I prefer to save the
charcoal for several reasons:

    a.  If charcoal is burned under the full force of the fan, the heat is
very
destructive to the fuel canister of the T-LUD.  However, if only a simmering
temperature is needed, low-air to the charcoal can give the right heat
without
damaging the fuel canister.

    b.  The T-LUD is optimal for utilizing the pyrolytic gases (about 
80% of the
heat value) with very clean combustion.  But the T-LUD has not been 
shown to be
any better (and might be worse?) at burning charcoal with low emissions 
than is
the case with the dedicated charcoal burners.  So, save the charcoal 
and make it
into briquettes for use in the most appropriate charcoal burners.

    c.  In terms of the CDM for greenhouse gases, fossil fuels create more
greenhouse gases, burning biomass is net-neutral for CO2 if replanting
occurs,
and only the T-LUDs can give the usable heat and still have a natural 
potential
to actually __reduce__ the greenhouse gases IF the charcoal is saved and
sequestered.  A family could generate a half tonne of charcoal from a year
of
cooking with a T-LUD.  And that half tonne is equivalent to about 1.5 tonnes
(1500 kg) of CO2.  Even if credited with only one tonne of CO2 per
household,
ten thousand households can yield 10,000 tonnes of improvement.  (Note: 
Compared to the corporations burning fossil fuels that do "buckets" of 
harm,
the T-LUDs in households can only do a few "drops" of benefits.)

2.  Roger wrote that: "maybe the biggest limitation of T-Luds is the
>> relatively modest energy conversion efficiency which limits the fuels we
>> can use in them."

T-LUDs have very high energy conversion (if I understand the term 
correctly), so
I think you are referring to not utilizing the energy of the charcoal.  
That is
a choice of the user.  If only 80% of the energy value of the switchgrass
pellets (or other fuels) is liberated, it remains the user's choice about
the
other 20% that is in the charcoal.  But that 20% is not "lost" because of
poor
energy conversion.

Also, the T-LUDs can probably use a greater variety of dry biomass than can
almost any other household-level combustion device.  Alexis Belonio 
openned our
eyes to the T-LUD ability to use rice husks.  Today I successfully burned
rice
husks in a simple T-LUD (with forced air) that probably will cost less than
US$10 per combustion unit to manufacture (including the blower for $2 
available
from Vietnam)(but excluding the costs of the "stove structure" that holds
the
pot and must look good in the kitchen).

Thank you for your comments thus far.

Paul
-- 
Paul S. Anderson, Ph.D., Geography professor - Emeritus
Telephone:  USA-309-452-7072 (residence and office)
Internet site:  www.ilstu.edu/~psanders
For my gasifier stoves info, go to:
http://bioenergylists.org/contributors#Paul_Anderson



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