[Stoves] Jatropha and its future

Jan Bianchi janbianchi at comcast.net
Tue Aug 16 18:47:11 CDT 2011


Lloyd, 

 

I’m glad to hear you were successful in burning jatropha seed.  We have the
same experience with it being smoky at the end of the burn which is why
we’ve been toying with being able to shut off the primary air toward the
end.

 

There seem to be many opinions about the possible toxicity of jatropha seed
smoke, many strongly felt.  I’m glad to have another vote for it not likely
being any more toxic than wood smoke.  We believe that.  Paul Anderson does
too.  But because we don’t have long experience with burning the seed, we
still think we would benefit from testing it.

 

Jan

  _____  

From: Lloyd Helferty [mailto:lhelferty at sympatico.ca] 
Sent: Tuesday, August 16, 2011 11:31 AM
To: Discussion of biomass cooking stoves
Cc: Jan Bianchi; c_espinosa1 at u.pacific.edu
Subject: Re: [Stoves] Jatropha and its future

 

Christina (And Jan),

  Just to let you (and everyone) know, I was able to successfully use/burn
whole Jatropha nuts in a natural draft Top-Lit- UpDraft (TLUD) stove (made
out of tin cans) at the recent CHAB Camp hosted by the Biomass Energy
Foundation in Belchertown, MA.  I did it outdoors on a windy day.
  While I did not intentionally inhale the smoke, I do not believe that the
smoke of the J-nuts was any more toxic than other types of smoke.  Hugh
McLaughlin actually explained that the smoke from a Jatropha fire was likely
just as toxic as from any other fire -- smoke of any kind tends to be
something one should not breathe [hence the warning on cigarette boxes].
 My little natural draft TLUD produced very little smoke once the secondary
airflow was adjusted properly and pyrolyzing the Jatropha nuts, although
when it was left unattended it did start smoking a little bit at the end of
the burn as the stove attempted to burn through the resulting biochar.
(Although if this were running indoors, I would probably be more worried
about the CO being produced than any toxicity that might arise from the
J-nuts.)



  Lloyd Helferty, Engineering Technologist
  Principal, Biochar Consulting (Canada)
  www.biochar-consulting.ca
  603-48 Suncrest Blvd, Thornhill, ON, Canada
  905-707-8754; 647-886-8754 (cell)
     Skype: lloyd.helferty
  Steering Committee member, Canadian Biochar Initiative
  President, Co-founder & CBI Liaison, Biochar-Ontario
    Advisory Committee Member, IBI
  http://www.linkedin.com/groups?gid=1404717
  http://www.facebook.com/group.php?gid=42237506675
  http://groups.google.com/group/biochar-ontario
  http://www.meetup.com/biocharontario/
  http://grassrootsintelligence.blogspot.com
   www.biochar.ca
 
Biochar Offsets Group: http://www.linkedin.com/groups?home=
<http://www.linkedin.com/groups?home=&gid=2446475> &gid=2446475
"Necessity may be the mother of invention, but innovators need to address
problems before they become absolute necessities..."


On 2011-08-10 8:33 PM, Jan Bianchi wrote: 

Christina

 

Yes, there are toxins in some varieties of jatropha which, if eaten, can
cause severe abdominal cramping and even death if not passed.  That is why
the plant operates so well as a hedge.  Animals won’t eat through it.  This
is well-known in communities which historically have jatropha available
where it is sometimes taken intentionally as a purgative.  

 

Jatopha oil has been burned for centuries with no known ill effect, and it
is currently being burned as a biodiesel fuel in cars in Europe. Today,
rolled logs of the mash left over from pressing the oil are used to fire
pizza ovens in Tanzania.  While the latter is not a practice we would
recommend, it does not seem to be having a purgative effect on current
customers!   But no thorough scientific studies have been done on the smoke.
A smoke study of jatropha oil and briquettes has recently been completed in
Europe, but it did not test for toxic compounds. This is one reason why we
insist on the stove being used outside with the smoke vented away from the
cook or perhaps eventually inside if the smoke can be adequately vented to
the outside.  Dilution of smoke in outside air is at least 100 times greater
than dilution indoors.  

 

The jatropha that originated in Central America is not believed to be toxic,
but the varieties grown throughout the rest of the world are.  The toxic
varieties are believed to contain more oil and are therefore the types
planted by the biodiesel companies.  Haiti is currently introducing the non
toxic variety there.  It would be our hope that anyone planting jatropha
from the start would use a non toxic variety, but we know it is not credible
that none of the toxic varieties available today throughout the tropics
would ever be used in our stove. 

 

The toxins in the seed and plant are curcin, a type of lectin, phorbol
esters, trypsin inhibiters, and phytates.   (Incidentally, curcin is not the
same as its far more deadly cousin ricin.  Please don’t make the mistake, as
some have in the past, that similar sounding names and family connections
mean they must have similar impacts.)   Whether these toxins are transferred
to the smoke itself and, if so, in what concentrations has not been
scientifically studied.

 

We do know some mitigating factors. Lectins and phytates are normally
detoxified by heating.  We know that the toxic effects of curcin, for
example, are destroyed by raising the temperature to 120 degrees. The mash
left over from jatropha oil production is currently being heated and and
then fed to animals.   Much less is known about the effects of the phorbol
esters in jatropha, but if they behave like other esters, they are unlikely
to survive the heat of our stove between ca 600 and 900C.  Wood itself has
toxic and carcinogenic qualities.  Just look at the creosote created in
fireplaces or charcoal production, yet we burn wood without any concern for
its toxicity, presumably because we are more familiar with it.

 

In order to address legitimate concerns that users may have about the smoke,
Jet City StoveWorks has been doing research on this issue.   We are in the
process of completing a literature study of jatropha’s toxicity and we are
currently in discussion with two laboratories to have smoke composition
tests done to identify the type and concentration of toxins that may
continue to exist in the smoke from our stove.  We are hopeful that, if the
type and concentration, if any, of toxic compounds in the smoke of jatropha
from our stove can be identified, then more reliable inferences can drawn by
toxicologists as to the likelihood of their being harmful in whatever
concentration they may be found.  We, of course, could never afford to do
the years of animal trials that would need to be undertaken to have absolute
certainty, but neither is any such certainty known about the smoke of
burning wood or the exhaust from diesel buses in our cities which we
tolerate daily.  Given what we know about jatropha, we believe that the use
of our stove will be at least better for a cook’s health than its three
stone fire alternative.  We are having the research done by competent third
parties.  We will place the results of the third party testing on our
website when they are completed.

 

One caveat.  I am neither a chemist nor a toxicologist, so if you (by which
I mean any listserve member who may wish to respond) are one, and you
believe I have stated something above that you believe to be inaccurate or
omitted some important item, please point it out.  I am a lawyer. I have
read a lot about this subject since the issue created so much controversy at
the ETHOS conference last January and I believe the above to be accurate.
Our literature study and the smoke studies will far be more definitive.

 

Jan

 

 

 

  _____  

From: stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Christina
Espinosa
Sent: Wednesday, August 10, 2011 2:00 PM
To: Discussion of biomass cooking stoves
Subject: Re: [Stoves] Jatropha and its future

 

Hi All,
Since the topic of jatropha came up I have been wondering a little about
it's use with stoves. Everything I have seen about stoves and jatropha so
far does not cover this. Maybe you all can help me answer these questions:

1. Jatropha is poisonous right? How is this being mitigated in the
processing of the seed (making press cakes, oil extraction)?
2. During combustion how is the poison altered?
3. What studies have been done showing that there is no harmful poison being
transferred while cooking?

Thanks!

Christina Espinosa
University of the Pacific '10
School of International Studies
c_espinosa1 at u.pacific.edu

On Wed, Aug 10, 2011 at 1:14 PM, Jan Bianchi <janbianchi at comcast.net> wrote:

Ron

 

Thank you for your questions about the Jiko Safi, the jatropha seed stove
that Jet City StoveWorks is currently testing.  I apologize for the delay in
response, but I had to pass the questions on to our developers as I am not
technically competent to answer all of them.

 

Why use jatropha in the Jiko Safi? Why whole seed? 

 

Frankly, we got involved in developing a jatropha seed stove because it
hadn’t been successfully done.  Past efforts resulted in a very fast, smoky
burn.   Jonathan Otto, who has been working in East Africa with farmers
engaged in jatropha production, knew about the past failures and jatropha’s
abundance there and urged us to try.   One of our developers, Dave Covert,
is an emeritus research professor in Atmospheric Sciences from the
University of Washington and the other, David Otto, is a contractor/
tinkerer extraordinaire in Seattle.  They had not traditionally been
“stovers,” but they are now.

 

As you know, jatropha is a very common tropical and sub-tropical non-food
plant with high energy content, available from Haiti to Bhutan to Indonesia.
It can be easily cultivated as a hedge row and on land not suitable for
other crops. In many areas of the world we have reached 'Peak Wood." Things
will not change for the better as population expands. One estimate suggests
less than 4% of the jatropha seed is harvested.   We believe this largely
unused rural energy source has potential as an alternative to tree burning
stoves, both charcoal and wood.  We believe that “there is no food security
without fuel security” and jatropha can be a secure fuel.  Our hope is to
make the alternative stove available to the people who are now walking for
hours past jatropha on their way to a diminishing supply of trees.  We
expect that eventually jatropha seed will also be available on the street
corners in villages and urban areas just as the much more expensive charcoal
and kerosene are now.

 

In several places around the world, there are experiments going on with
jatropha seed cake and rice hull blends where seed is purchased from the
farmer then transported to a center with the electricity necessary to run
three machines: an extractor that removes about 95% of the oil, a hammer
mill processes the seed cake with the rice hulls and other ingredients, and
a pelletizer to form the material in a way it can be burned.  Finally the
pellets are transported back to the farmer/cook. This approach to using
jatropha could prove to work well in areas that have the machinery and the
electricity. 

 

In the meantime, Jet City StoveWorks is focusing on a whole seed as a fuel
for its simplicity, availability and very small carbon footprint as well as
putting the farmer/ cook in charge of her fuel.  It is a natural pellet
stove.

 

How did this stove come to have a central air duct, a chimney, no port
adjustment equipment, the amount of secondary air holes etc.?

We started with several specific goals: 

(1)   The stove was specific to jatropha with its high energy content. Other
seeds with high oil content may work: castor, croton and sunflower seeds
come to mind, though some have competing uses.  We will be testing them in
time. 

(2)   The stove must be direct, intuitive and simple to use, requiring only
a demonstration of how to light a TLUD stove. 

(3)   The stove will operate with natural draft: without fan if possible and
without moving parts--the bane of all machines in developing areas.

(4)  The stove must be designed to have the lowest possible emissions and
remove whatever pollution that is created away from the cook and her family.


(5)   The stove must be durable and long lasting. 

(6)   The stove's truly important field test is its success in meeting the
cook's needs as she prepares daily meals because only then will it be used.

 

The stove evolved over the past twelve months to its current form. Starting
with TLUD principles (e.g. seeking the correct balance of primary and
secondary air,  thank you Paul Anderson), we then made rough calculations of
the energy captured in the seed and started building and modifying in a
typical iterative process. Typical stove designs all had too much primary
air and often a promising design would work well in some respect but not
all.  For example, we had one model that would boil water like crazy but the
temperature just above the fuel was over 1100 C.  When the central air duct
was added in a week long testing at the wonderful facility at CREEC in
Uganda, the opposing secondary air currents brought the turbulent flame down
to a flat, reliable pattern.  We are experimenting with an adjustment that
allows the primary air to be shut off at the end of a burn to cut off the
smoke that usually occurs at that point.  We are currently doing pollution
testing, advocate open source principles and so will be posting information
at our new web site which is currently under construction.
http//jetcitystoveworks.com  

 

The Jiko Safi is currently being manufactured by metal workers in Arusha,
Tanzania, who we have assisted in the financing of the tools and jigs
necessary to produce the stove within the tolerances required.  That is the
model we expect to use wherever we introduce the stove so there will be
local economic development opportunities as well as someone available to
repair the stove, if necessary.  It is currently designed to be used only
outside.  We hope that kitchen testing will tell us whether it can be used
indoors as long as the chimney is ventilated to the outside.

 

The testing and manufacture is under being done with the assistance of the
Department of Agriculture, Partnership for Development, JANI, (Jatropha
Agriculture and Nutrition Initiative in Tanzania, and Pamoja, Inc. 

 

Thanks for your interest and questions.  We welcome suggestions.

 

Jan 

 

 

 

  _____  

From: rongretlarson at comcast.net [mailto:rongretlarson at comcast.net] 
Sent: Monday, August 08, 2011 8:21 PM
To: Discussion of biomass cooking stoves; Jan Bianchi


Subject: Re: [Stoves] Jatropha and its future

 

Jan and list

  This is to better understand your nice Jet City stove .(for non West Coast
USA readers - that means Seattle  - which has a lot of Biochar activity)

 1.   How did you happen to center on Jatropha?   Have you experimented both
with whole seeds and the residue after pressing and how does stove operation
differ?  Have you tried anything like wood chips?

  2.  I think the flame pattern in your stove is wonderful.  As you say,
very compact and obviously very turbulent - which must be desirable.  I am
pretty sure the idea of central secondary air has been mentioned n the past
on this list as a possibility - but I don't recall ever seeing it in
practice.  Can you describe a bit how you came to the present dimensions ?

3.  I worry that you may now have too much secondary air - as the flame
seems to only be holding near the bottom row or two.  Have you any way of
knowing what the dilution factor is?  Tried operation with a smaller number
of interior holes  (just plugging some progressively)?

4.  The central "column" (maybe with a different height) looks like it might
be able to hold a pot of the right size - since you would then already have
the "convection shield" that gives considerable efficiency improvement. And
you could retain the chimney height needed to get your desired air flow and
power level. Ever been tried?

5.  I have felt that controlling primary air supply to be an important
feature of pyrolysis stoves (TLUDs).  It seems your bottom set of holes
could receive a rotating or sliding (or up and down) plate to accomplish
that.  Has that ever been tried?  (This being accomplished nicely with a
blower in the "Paul Olivier design also being discussed today.)

Best of luck with what you are doing.  Nice work.

Ron
 

  _____  

From: "Jan Bianchi" <janbianchi at comcast.net>
To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org>
Sent: Monday, August 8, 2011 9:56:48 AM
Subject: Re: [Stoves] Jatropha and its future

Roger

 

That stove in the ETHOS pictures was a prototype version. The stove is now
made from steel. 

 

Jan

Sent from my iPhone


On Aug 8, 2011, at 8:51 AM, Fireside Hearth
<firesidehearthvashon at hotmail.com> wrote:

Good morning....

I am curious about a couple of the pictures of the stove by Otto....do I see
galvanized sheet metal used in area's of high heat? the text talks about
800deg C. (1472 f.) if there is galvanized materials in contact with these
temps it is quite possible that galvanic poisoning could kill the operator.
A friend of mine was welding inside a galvanized pipe (large culvert for
water drainage) when his oxygen mask failed and a green colored gas entered
his lungs causing him some of the most horrible pain and near death
experience imaginable. The other question I have is the material thickness.
It does not look like this will withstand these temperatures for long. What
is the life expectancy of this unit when exposed to these temps. Does it
make sense to build something a bit more stout and send less of them to the
land fill as the "burn out" too quickly with these exposures. Not all ways
can we value things simply on "cost per unit" but "cost to the environment"
should be taken into account. After looking at the industrial area's of
northern China it seems to me that it is the environment which is paying for
our "cheap" flat screens.  


  _____  


From: janbianchi at comcast.net
Date: Mon, 8 Aug 2011 08:08:37 -0700
To: stoves at lists.bioenergylists.org
Subject: Re: [Stoves] Jatropha and its future

Jet City StoveWorks is currently conducting kitchen tests of the jatropha
seed stove Marc refers to in Tanzania.

 

  Jatropha grows wild throughout the tropics as well as recently as
biodiesel  crop there. Alternatively, and more productively,  it can be
grown as a hedge around land holdings so it need not displace land for food
production.  That produces enough seed to fuel the family cookstove for a
year as well as have some left over to sell into the Jatropha market. It
costs at least four times less than a comparable burn time for wood and six
times less than charcoal.

 

We are continuing CO and PM testing and hope to have our test results online
by next month.  We had a stove at Aprovecho's stove camp couple of weeks ago
and will have one at Paul Anderson's TLUD camp in MA in August. 

Sent from my iPhone


On Aug 8, 2011, at 2:10 AM, Marc Pare <mpare at gatech.edu> wrote:

Crispin, re exisiting Jatropha stoves:

 

There was this one at ETHOS this year by J. Otto and friends:

http://www.vrac.iastate.edu/ethos/proceedings2011/OttoOttoCovert_JatrophaSee
dCookingStoveDevelopmentPromotion.pdf

and a quick picture of it running outside in Kirkland:

http://smallredtile.tumblr.com/post/3246717546/marc-in-the-wild-there-were-m
any-arguments-about

 

It burns whole seeds in a natural draft TLUD. Draft is augmented by an inner
air pipe (lots of pictures of the assembly in the ETHOS presentation)


Marc Paré
B.S. Mechanical Engineering
Georgia Institute of Technology | Université de Technologie de Compiègne

my cv, etc. | http://notwandering.com

On Mon, Aug 8, 2011 at 1:36 AM, Crispin Pemberton-Pigott
<crispinpigott at gmail.com> wrote:

Dear Friends

I am not sure how many stove are being worked on as Jatropha seed or oil or
cake burners, but my understanding was the main thrust was to put to use
some of the leftovers from biofuel production, especially that was the focus
in Tanzania.

It seems those farmers who invested in Jatropha production lost about $65
per ha http://pubs.acs.org/doi/full/10.1021/es201943v so my question is
whether or not there is much point in working on (perhaps) whole seed
stoves. Perhaps if the J-oil industry suffers a quick death there will still
be a meaningful supply of oily seed fuel that  can be burned relatively
easily with a decent performance and controllability. At least until they go
back to sunflower which looks a lot more promising.

Has anyone made a sunflower seed burning stove? The oil runs up to 49% on
some varieties.

Always looking for new ideas


Regards

Crispin

 

 


_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/

 

_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/


_______________________________________________ Stoves mailing list to Send
a Message to the list, use the email address stoves at lists.bioenergylists.org
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org for more Biomass Cooking Stoves, News and Information see our web site:
http://www.bioenergylists.org/______________________________________________
_Stoves mailing list


to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/


_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/


_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/









_______________________________________________
Stoves mailing list
 
to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org
 
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org
 
for more Biomass Cooking Stoves,  News and Information see our web site:
http://www.bioenergylists.org/
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20110816/f8f9afd0/attachment.html>


More information about the Stoves mailing list