[Stoves] Jatropha fruit as fuel?

Sat Jan 19 17:23:35 CST 2013

Otto - FYI jatropha presscake (the mealy material left over once oil has
been pressed out of the seeds) can be directly pelletized without further
processing. It's pretty easy to pelletize, even with a small, cheaper (e.g.
benchtop) pellet press. The mealy presscake still contains some of the oil
(think coffee grounds) and it pelletizes well without worry over moisture
content or having to use a binder.

The pellets burn in a TLUD similar to wood or other pellets, at least by
visual observation and temperature recording. I have colleagues that have
tried to make cooking briquettes with jatropha seedcake and had a very
smoky, smouldery combustion. I believe there are concerns of some
potentially toxic emissions (phorbol esters, other compounds?). I have not
tested the emissions from TLUD charring jatropha pellets, but there was no
visible smoke and the gasifier seemed to operate fine as it does with other
types of pellets. It would be interesting to know if firing jatropha
pellets in a TLUD destroys the phorbol esters and other problematic
compounds instead of emitting them.

I first tried to char un-pelletized jatropha seedcake in the TLUD - because
it is mealy like coffee grounds no draft could get through and it was a
total fail - lots of smoke poured out! This brought the fire department to
our Colorado backyard during a fire ban. Whoops.

Also FYI char made from TLUD jatropha pellets performed similar for
herbicide uptake from simulated natural water as chars made in the same way
from pine pellets, bagasse pellets, and bamboo pieces.

Josh

On Sat, Jan 19, 2013 at 12:29 PM, Jonathan Otto <ottojonathan at hotmail.com>wrote:

>  Otto,
>
>
>
> Whole Jatropha seeds can be picked from hedges on-farm and used directly
> in our jiko safi gasification stove without any further effort (except
> maybe for some sun drying if harvested during a damp season) … the most
> decentralized, efficient sustainable fuel system I can imagine.
>
>
>
> Sure, urban jiko safi users will need to buy their fuel seeds, so a
> commercial system for transport and retail sale of seed will be needed
> eventually, likely mimicking some aspects of the charcoal trade. But it’s
> just whole, unprocessed seed.
>
>
>
> Concerning pelletized Jatropha fuel, I would like to understand the
> advantages you find in going through the costs and effort (including energy
> losses) of processing seeds to expel the oil, then probably milling the
> press cake and shells (?) to uniform size/texture, then extruding or
> otherwise forming the mixture into pellets, and finally distribute the
> fuel, some of which will go back to the same farmers that grew the Jatropha
> seed in the first place?
>
>
>
> I know there are technical advantages to gasification of uniform-sized
> pellets, but it seems to me that round or ovoid shaped seeds like Jatropha,
> castor (I know, more poisons!), shea or croton megalocarpus provide this
> same advantage, without going through the pelletization process.  What am
> I missing?******
>
>
>
> Otto, the minor
>
>
>
> P.S.  It's too late for me to retire 'on time'
>  ------------------------------
> From: terra-matricula at hotmail.com
> To: stoves at lists.bioenergylists.org
> Date: Sat, 19 Jan 2013 17:23:37 +0100
>
> Subject: Re: [Stoves] Jatropha fruit as fuel?
>
> Jonathan,
>
> We have got some samples of pelletized jatropha shells and seeds from
> Zambia, after the oil has been extracted and we feel that is the way
> forward.
>
> We will update you on the progress, so you will be albe to retire "on
> time".................:)
> We are not so worried about PM in natural draft gasifiers, but thanks for
> the concern.
>
> Otto........................
>  ------------------------------
> From: ottojonathan at hotmail.com
> To: stoves at lists.bioenergylists.org
> Date: Sat, 19 Jan 2013 09:03:35 -0500
> Subject: Re: [Stoves] Jatropha fruit as fuel?
>
> Otto-
>
> You 'would guess' wrong.
>
> 'We should be very careful advising people' about such unsupported
> conclusions.
>
> The challenges of gasifying oils found in seeds, notably the oils of
> Jatropha seed, in a cookstove are far different from working with
> most pellets formulations.
>
> I keenly look forward to news of your all-fuel stoves that will handle J
> seeds, and the results of your tests. I sincerely hope you develop this
> soon, so I can finally retire in peace.
>
> Oh, and when you do tests, please include particulates in your emissions
> testing, so we can finally end all this hand wringing about 'these types of
> fuel'.
>
> >From the cheeky other Otto,
>
> Jonathan
>  ------------------------------
> From: terra-matricula at hotmail.com
> To: stoves at lists.bioenergylists.org
> Date: Fri, 18 Jan 2013 23:23:48 +0100
> Subject: Re: [Stoves] Jatropha fruit as fuel?
>
> Dear stovers,
>
> I would guess that "any" gasifier will burn jatropha seeds or pellets
> cleanly and efficient, as long as the moisture content are less than 10%.
>
> We have in the pipeline to test a new design of natural draft gasifiers,
> using jatropha seeds and pellets, for emmissions and toxcic fumes.
>
> We should be very carefull adviceing people using these types of fuel,
> before it has been carefully tested by independent institutions.
>
> Have a nice weekend.
>
> Otto (not the famous one..........:)
>
>  ------------------------------
> From: crispinpigott at gmail.com
> To: stoves at lists.bioenergylists.org
> Date: Fri, 18 Jan 2013 10:19:11 -0500
> Subject: Re: [Stoves] Jatropha fruit as fuel?
>
>  Dear Jonathan
>
>
>
> I am interested in the general layout and dimensions of a stove that will
> burn the seeds well. Are you sharing at this time anything regarding the
> design?
>
>
>
> Thanks
> Crispin
>
> ++++++++
>
>
>
> Dear Joyce and stovers all,
>
> My regrets for not responding to this request 6 months ago.  I admit that
> it got lost in my messy inbox which I have now reduced from 6000 messages
> to a mere 2400, and in the process uncovered Joyce's email.
>
> Burning Jatropha seeds whole or in briquettes in open cooking arrangements
> is a bad idea.  It produces a smoky, smelly fire and probably exposes cooks
> to toxic emissions.  I even question burning Jatropha oil in lamps in
> enclosed areas for the same reason. Maybe others know of emissions studies.
> [snip]
>
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-- 
Josh Kearns
PhD Candidate, Environmental Engineering
University of Colorado-Boulder
Visiting Researcher, North Carolina State University

Director of Science
Aqueous Solutions
www.aqsolutions.org

Mobile: 720 989 3959
Skype: joshkearns
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