[Stoves] Jatropha and its future
Lloyd Helferty
lhelferty at sympatico.ca
Tue Aug 16 13:31:21 CDT 2011
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=&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 <mailto:c_espinosa1 at u.pacific.edu>
>
> On Wed, Aug 10, 2011 at 1:14 PM, Jan Bianchi <janbianchi at comcast.net
> <mailto: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 <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>
> [mailto: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
> <mailto:janbianchi at comcast.net>>
> *To: *"Discussion of biomass cooking stoves"
> <stoves at lists.bioenergylists.org <mailto: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
> <mailto: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 <mailto:janbianchi at comcast.net>
> Date: Mon, 8 Aug 2011 08:08:37 -0700
> To: stoves at lists.bioenergylists.org
> <mailto:stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Jatropha and its future
>
> JetCity 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
> <mailto: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_JatrophaSeedCookingStoveDevelopmentPromotion.pdf
>
> and a quick picture of it running outside in Kirkland:
>
> http://smallredtile.tumblr.com/post/3246717546/marc-in-the-wild-there-were-many-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 <mailto: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
>
>
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