[Stoves] Stoves Digest, Vol 14, Issue 17
Paul Olivier
paul.olivier at esrla.com
Fri Oct 14 18:13:05 CDT 2011
Trevor,
You are right about the fixed carbon content of rice hulls at about 15%.
If the ash content is 20%, then this leaves a volatile matter content of
64%.
This calculation is on a dry weight basis.
If we gasified all volatile matter,
the fixed carbon content of the char would rise to about 43%,
and the ash content would rise to about 57%.
But typically rice hull biochar has an ash content of about 40%.
This means that there is still a lot of volatile matter that remains in the
biochar.
In the case of rice hulls,
the amount of volatile matter that remains in the biochar is determined by
the rate of gasification.
At times the yield in rice hull biochar by weight is as low as 30%.
At times the yield is as high as 50%.
If the rate of gasification is high, high temperatures within the reactor
are reached.
With high temperatures, more volatile matter is gasified.
We need operating temperatures well beyond 1000 C before fixed carbon gets
gasified.
In my opinion it makes little sense to gasify fixed carbon.
Thanks.
Paul
On Thu, Oct 13, 2011 at 3:53 PM, Trevor Richards <febiochar at gmail.com>wrote:
> Tests I've seen on rice husk char showed 15% fixed carbon.
> I do not recall seeing a biochar definition, specifying a minimum fixed C.
> How low could the C% be & still be defined a biochar?
>
> On 13 October 2011 03:00, <stoves-request at lists.bioenergylists.org> wrote:
>
>> Send Stoves mailing list submissions to
>> stoves at lists.bioenergylists.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>>
>> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>>
>> or, via email, send a message with subject or body 'help' to
>> stoves-request at lists.bioenergylists.org
>>
>> You can reach the person managing the list at
>> stoves-owner at lists.bioenergylists.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of Stoves digest..."
>>
>>
>> Today's Topics:
>>
>> 1. Re: burning rice husk (Crispin Pemberton-Pigott)
>> 2. Re: burning rice husk (Crispin Pemberton-Pigott)
>> 3. Re: burning rice husk (CHRISTA ROTH)
>> 4. Re: burning rice husk (Frank Shields)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 12 Oct 2011 11:19:02 -0400
>> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
>> To: "'Discussion of biomass cooking stoves'"
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] burning rice husk
>> Message-ID: <037501cc88f2$500af3e0$f020dba0$@gmail.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Dear Christa
>>
>>
>>
>> There are other initiatives to make stoves based on the approach Alexis
>> has
>> taken. Paul has other models that show some promise as well.
>>
>>
>>
>> The Mayon Turbo Stove is not perfected yet and I don't think much is being
>> invested in trying. It holds promise from the point that it does not
>> require
>> a fan. I worked on one here (in Waterloo) earlier this year together with
>> two interns from REAP. We doubled the overall efficiency but created new
>> problems that it got too hot. It needs additional work to keep the fuel
>> cool. There are of course other ways to burn the fuel with natural draft.
>> Maybe with the advent of cheap power from TEGs we will all make fan stoves
>> and not worry about natural draft any more.
>>
>>
>>
>> The MTS has the important advantage that is can be refuelled continuously
>> at
>> your convenience. It does not need to be loaded in batches.
>>
>>
>>
>> Regards
>>
>> Crispin
>>
>>
>>
>>
>>
>>
>>
>> +++++++
>>
>>
>>
>> The best rice-husk burning stoves I know of are the ones based on the
>> tremendous work of Alexis Belonio. Paul Olivier' s work in Vietnam has
>> taken
>> rice-husk burning stoves in the household-size range to another level,
>> uncomparable with natural-draft stoves like the Mayon Turbo, LoTrau or
>> whichever. Paul has generously shared a lot of his work on this list in
>> the
>> last days, so you can look more details up from the links provided there
>> or
>> consult the section on rice-husk burning gasifiers, pages 43-48 of the
>> manual microgasification
>> http://www.gtz.de/de/dokumente/giz2011-en-micro-gasification.pdf,
>>
>> it contains all I found as per last year. If anybody knows of models that
>> are not included there, please let me know, so that they can be included
>> in
>> the next update.
>>
>> regards
>>
>> christa
>>
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL: <
>> http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20111012/ae795c21/attachment-0001.html
>> >
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Wed, 12 Oct 2011 11:19:02 -0400
>> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
>> To: <rajan_jiby at dataone.in>, "'Discussion of biomass cooking stoves'"
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] burning rice husk
>> Message-ID: <037f01cc88f2$53782e30$fa688a90$@gmail.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Dear Rajan
>>
>> One stove that burns whole rice hull efficiently is the Mayon Turbo Stove.
>>
>> Regards
>> Crispin
>>
>>
>> +++++++
>>
>> I do not know whether a stove can efficiently burn rice husk.
>>
>> But it seems rice husk can be burnt efficiently in FBC ( fluidised bed
>> combustion ) boilers. There are several medium sized FBC boilers operated
>> all over India. So the fuel need not go waste.
>>
>> Regards,
>>
>>
>> Rajan
>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Wed, 12 Oct 2011 17:39:49 +0000
>> From: CHRISTA ROTH <stoves at foodandfuel.info>
>> To: Discussion of biomass cooking stoves
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] burning rice husk
>> Message-ID: <B4B60F1C-E72F-44B4-8B49-6B22E3F30982 at foodandfuel.info>
>> Content-Type: text/plain; charset="windows-1252"; Format="flowed";
>> DelSp="yes"
>>
>> Crispin, see below:
>> Am 12.10.2011 um 15:19 schrieb Crispin Pemberton-Pigott:
>>
>> > There are other initiatives to make stoves based on the approach
>> > Alexis has taken. Paul has other models that show some promise as
>> > well.
>> CR: Which Paul do you mean? I was talking of Paul Olivier below, who
>> has taken Belonios concept to a new era.
>>
>> >
>> > The Mayon Turbo Stove is not perfected yet and I don?t think much is
>> > being invested in trying. It holds promise from the point that it
>> > does not require a fan. I worked on one here (in Waterloo) earlier
>> > this year together with two interns from REAP. We doubled the
>> > overall efficiency but created new problems that it got too hot. It
>> > needs additional work to keep the fuel cool. There are of course
>> > other ways to burn the fuel with natural draft. Maybe with the
>> > advent of cheap power from TEGs we will all make fan stoves and not
>> > worry about natural draft any more.
>> >
>> > The MTS has the important advantage that is can be refuelled
>> > continuously at your convenience. It does not need to be loaded in
>> > batches.
>> CR: But the disadvantage I noted is that it needs a lot of attention:
>> we had to tap the stove every two minutes last year in Belchertown
>> with the colleagues from REAP to assist gravity and make the rice
>> husks fall down, otherwise there was no continuous feed adn the fire
>> would go out. Maybe that 'spoonfeeding' can be reduced with skills and
>> acquired habits, but as an unskilled user I found it rather
>> inconvenient.
>> >
>> > Regards
>> > Crispin
>> >
>> >
>> >
>> > +++++++
>> >
>> > The best rice-husk burning stoves I know of are the ones based on
>> > the tremendous work of Alexis Belonio. Paul Olivier' s work in
>> > Vietnam has taken rice-husk burning stoves in the household-size
>> > range to another level, uncomparable with natural-draft stoves like
>> > the Mayon Turbo, LoTrau or whichever. Paul has generously shared a
>> > lot of his work on this list in the last days, so you can look more
>> > details up from the links provided there or consult the section on
>> > rice-husk burning gasifiers, pages 43-48 of the manual
>> > microgasification
>> http://www.gtz.de/de/dokumente/giz2011-en-micro-gasification.pdf
>> > ,
>> > it contains all I found as per last year. If anybody knows of models
>> > that are not included there, please let me know, so that they can be
>> > included in the next update.
>> > regards
>> > christa
>> > _______________________________________________
>> > 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/20111012/702a38b7/attachment-0001.html
>> >
>>
>> ------------------------------
>>
>> Message: 4
>> Date: Wed, 12 Oct 2011 09:27:59 -0700
>> From: "Frank Shields" <frank at compostlab.com>
>> To: "'Discussion of biomass cooking stoves'"
>> <stoves at lists.bioenergylists.org>, <rajan_jiby at dataone.in>
>> Subject: Re: [Stoves] burning rice husk
>> Message-ID: <EF2941FD30314943BF1939C78F58E7CE at cl.local>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Stovers,
>>
>> I was talking to a rice grower in Northern Calif. and found out that Wild
>> Rice has much less silica in the hulls than White Rice. I haven't tested
>> wild rice hulls to confirm.
>>
>> Frank
>>
>> Frank Shields
>> Control Laboratories, Inc.
>> 42 Hangar Way
>> Watsonville, CA 95076
>> (831) 724-5422 tel
>> (831) 724-3188 fax
>> frank at compostlab.com
>> www.compostlab.com
>>
>>
>> -----Original Message-----
>> From: stoves-bounces at lists.bioenergylists.org
>> [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Crispin
>> Pemberton-Pigott
>> Sent: Wednesday, October 12, 2011 8:19 AM
>> To: rajan_jiby at dataone.in; 'Discussion of biomass cooking stoves'
>> Subject: Re: [Stoves] burning rice husk
>>
>> Dear Rajan
>>
>> One stove that burns whole rice hull efficiently is the Mayon Turbo Stove.
>>
>> Regards
>> Crispin
>>
>>
>> +++++++
>>
>> I do not know whether a stove can efficiently burn rice husk.
>>
>> But it seems rice husk can be burnt efficiently in FBC ( fluidised bed
>> combustion ) boilers. There are several medium sized FBC boilers operated
>> all over India. So the fuel need not go waste.
>>
>> Regards,
>>
>>
>> Rajan
>>
>>
>> _______________________________________________
>> 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/
>>
>>
>> End of Stoves Digest, Vol 14, Issue 17
>> **************************************
>>
>
>
> _______________________________________________
> 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/
>
>
>
--
Paul A. Olivier PhD
27C Pham Hong Thai Street
Dalat
Vietnam
Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20111015/0ad19ec4/attachment.html>
More information about the Stoves
mailing list