[Stoves] Torrifaction topics Re: Pellet stoves - risks
Paul Anderson
psanders at ilstu.edu
Sun Sep 6 07:32:00 CDT 2015
Dear all,
While agreeing with Frank and Dean, I suggest that there are sufficient
"degrees of torrification" that we should subdivide the discussion.
1. Wet or green wood High moisture content (MC)
2. Dried in 20% MC range
3. Dried to 10% MC or less
4. Kiln dried (heated to ???? degrees C)
5. Super dried (heated to maybe 120 C)
6. Toasted (slightly browning) 120 to 180 C ???
7. Early torrified 180 - 240 C ??
8. Fully torrified 240 - 300 C ??
9. Undergoing pyrolysis above 300 C ???
10. And then we have different "chars" based on temperatures during
production, 400 C, 450 C, 550 C, 700 C, 900 C
LOTS of question marks there. Frank and others can refine this much
better. Issues of MC and temperatures and "names" (and related to
sufficient time to have the heat impact reach the center of the pieces
of biomass, not just flash heating), and probably more variables.
To just say "torrified" leaves too many uncertainties and possible
mis-understandings / assumptions by the large number of readers in
different cultures and with different experiences.
I can say that TLUD stoves (when properly made and with consistent MC in
the fuels) work very well with the 3, 4, 5, and 6 (above) fuels. They
do not like much moisture content, and they do not want the fuel to be
already partially charred.
Reasonable quality fuel supply is so important for TLUD acceptance.
More work could be done about this.
Paul
Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: psanders at ilstu.edu
Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.com
On 9/5/2015 11:45 PM, Frank Shields wrote:
> Dear Dean, Stovers,
>
> I have not worked with stoves but working with all types of pellets
> (paper, manures, etc.) and good quality wood pellets I find they burn
> in pipes very poorly and seem they are really just good for pellet
> stoves dropping in one at a time.
> I think you may be on to something in regards to torrifying to some
> extent before using to get a cleaner combustion. I see the real
> challenge is quality control because torrification takes place in a
> very narrow range and it is so easy to have a ‘run-a-way’ combustion
> that heats higher than the setting you want. I was able to achieve
> that in my pipes but only after much practice and s l o w l y
> raising the temperature to desired amount. Not sure how this would be
> done commercially. It would be a very interesting project.
>
> We also may be able to get clean combustion by finding constituents in
> the pellets (and all biomass for that matter) that create these large
> organic volatile structures that give problems and eliminate them from
> the fuel.
>
> Regards
>
>
> Frank
>
>
>
>
>
> Frank Shields
> franke at cruzio.com <mailto:franke at cruzio.com>
>
>
>
>
>> On Sep 3, 2015, at 12:28 PM, Dean Still <deankstill at gmail.com
>> <mailto:deankstill at gmail.com>> wrote:
>>
>> Hi Frank,
>>
>> After limited experience in Uganda and China my experience is that
>> it's not easy to make clean burning recipes for biomass pellets.
>>
>> Seems like the torrified pellets emit less PM but we need to do more
>> tests.
>>
>> Best,
>>
>> Dean
>>
>> On Thu, Sep 3, 2015 at 8:44 AM, Frank Shields <franke at cruzio.com
>> <mailto:franke at cruzio.com>> wrote:
>>
>> Dear Chispin and stovers
>>
>>
>> Of course no mention of the quality of the pellets! In the U.S.
>> The go through standard testing and results labeled
>> On bags. But pellets are made of all sorts of materials and
>> energy values and volatile profiles. It would seem this would
>> be part of the discussion.
>> Thanks
>> Frank
>>
>> Sent from my iPhone
>>
>> On Sep 3, 2015, at 6:13 AM, Crispin Pemberton-Pigott
>> <crispinpigott at outlook.com <mailto:crispinpigott at outlook.com>> wrote:
>>
>>> Dear Friends
>>>
>>> There is a broad move around the world to create pelleted fuel
>>> from biomass and burn it in tighter spaces. This report was
>>> noted in the Alliance for Green Heat newsletter:
>>>
>>> *Updated on the Mt. Vernon pellet stove recall*
>>> <http://r20.rs6.net/tn.jsp?f=001d7dcszljjgfEKYA31aaHyRsMRRejQSaDUDJHpy5B3lPW1W0QcteHERbDFukIhEc2-_1cKtvym49J_ai7zvt1WWN26UenG3N6joIskOVraQhcc__S5dpEwVlcw8pbpwWuwRufyvZSstnraBJTXAbr2wOPL-tX7Wypj3swduscC5I1Staun8b2olWMeGwuEsLEKsSA0qsYd2J1B5b7fDXOH7vLn_jPI3y12xty5nULquL9LCJu6LE7P-Ysu5qiL45LFwfyKNL4feu5XOzEawUh0a7X5VAZM8fb7F4K1l1kHGeFIFftvkxNTEEi9J_I05V6LKmiIZSk4GOQXJRAMRf5NDba52L-Wn_9jVkbpqju9Kifq8bMZm_xowV5Qn2NerYbUfu00_a4isbrvL9gktLkSQ==&c=WnPhxOQ3V-ic1ZJ3NBDpcipfRPq-UdIrBKPYwMfkxe-_CRS45fkQ4w==&ch=gnDbpciWOWhz6yV0o8Zdcoli15r_rpgR21xk0iBJKKi_KYRnwLVmTw==>
>>>
>>> Last month, we reported on the recall of 2,000 Mt. Vernon E2
>>> pellet stoves after about 6 experienced explosions that
>>> shattered the glass in the front door. No injuries have been
>>> reported. The Alliance wrote to HHT asking for clarifications
>>> about what caused the malfunction and whether the stove would be
>>> 3rd party tested again for safety. *Click here*
>>> <http://r20.rs6.net/tn.jsp?f=001d7dcszljjgfEKYA31aaHyRsMRRejQSaDUDJHpy5B3lPW1W0QcteHEfKhE4oT8BuuAHDwJ1L0g7GrKo5I0xEbbDvkpCt65Xds638GUTKpc9WxdvAozGBIprVOl7vL1wQKB10dTQFUofpAQnr3z9i2zwxCfiQA3rCg4PVvKxSMWgMWDhYiC_fJ7rGJlBpUwsdpb9A-KCa9c_WZg3sRbG1GpSOEsBvotEVw3FLKELU68l1aktAt4KqIrr-AbESuj8iSP6u9wdRQU3L5aMshSI5ocFejIUjrSB94PP9Q2h_zrmWcq3brFPbj1VqWZSiFfmDp50WpCw2b2SOvJ-9NqzbOgn8sgdzIHO2tNWqczgkuFI6d7bzwPt4D_g==&c=WnPhxOQ3V-ic1ZJ3NBDpcipfRPq-UdIrBKPYwMfkxe-_CRS45fkQ4w==&ch=gnDbpciWOWhz6yV0o8Zdcoli15r_rpgR21xk0iBJKKi_KYRnwLVmTw==>for
>>> a copy of the HHT response.
>>>
>>> The drive to create better combustion often means having a
>>> staged gasification-then-burning type of design. That may be a
>>> source of problems.
>>>
>>> I know of at least one instance of a very modern TLUD coal stove
>>> explosion in Ulaanbaatar when the operator refuelled it with a
>>> significant amount of lignite (high volatiles) while it was
>>> already very hot. This generated a huge amount of combustible
>>> gas while simultaneously extinguishing the gas flame.
>>> Eventually it heated up to the point that the gas ignited and it
>>> blew flaming fuel out of the top of the stove, around the room.
>>> A public education campaign tried to prevent exactly this sort
>>> of mis-operation.
>>>
>>> Regards
>>>
>>> Crispin
>>>
>>> _______________________________________________
>>> Stoves mailing list
>>>
>>> to Send a Message to the list, use the email address
>>> stoves at lists.bioenergylists.org
>>> <mailto: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://stoves.bioenergylists.org/
>>>
>>
>> _______________________________________________
>> Stoves mailing list
>>
>> to Send a Message to the list, use the email address
>> stoves at lists.bioenergylists.org
>> <mailto: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://stoves.bioenergylists.org/
>>
>>
>>
>>
>>
>> --
>> Dean Still
>> Executive Director
>> Aprovecho Research Center
>> PO Box 1175
>> 76132 Blue Mountain School Road
>> Cottage Grove, OR 97424
>> (541) 767-0287
>> _______________________________________________
>> Stoves mailing list
>>
>> to Send a Message to the list, use the email address
>> stoves at lists.bioenergylists.org <mailto: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://stoves.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://stoves.bioenergylists.org/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20150906/819d2bd8/attachment.html>
More information about the Stoves
mailing list