Josh and Jonathan (Otto), Yes, we are talking about the presscake of Jatropha and it was processed into pellets localy in Zambia, quite easily and with "simple" tools - (no waste of energy) We had the same experience as your colleagues using briquettes made out of ricehusks and sawdust.They even started to glow like charcoal early in the gasification process and produced smoky and smouldery combustion. Thast why we prefer to use pellets of best possible quality. I hope you are correct about the gasification of jatropha pellets will destroy the phorbol esters and other problematic compounds instead of emitting them.Iam a bit worried about the forced draft units, while they seems to blow some parts of the ash and gases into the open air or room. May be the char from Jatropha could have a pestecide effect as well? Otto Date: Sat, 19 Jan 2013 18:23:35 -0500 From: [email protected] To: [email protected] Subject: Re: [Stoves] Jatropha fruit as fuel?
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 <[email protected]> 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: [email protected] To: [email protected] 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: [email protected] To: [email protected] 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: [email protected] To: [email protected] 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: [email protected] To: [email protected] 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] _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] 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 [email protected] 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 [email protected] 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 [email protected] 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 [email protected] 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/ -- Josh Kearns PhD Candidate, Environmental Engineering University of Colorado-BoulderVisiting Researcher, North Carolina State University Director of ScienceAqueous Solutions www.aqsolutions.org Mobile: 720 989 3959 begin_of_the_skype_highlighting 720 989 3959 end_of_the_skype_highlighting Skype: joshkearns _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] 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/
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