[Stoves] Torrified Pellets

Mon May 25 12:45:29 CDT 2015

I agree with Crispin and Ron that gr/min needs firepower to guide stove
development.

Best,

Dean

On Mon, May 25, 2015 at 9:53 AM, Ronald Hongsermeier <rwhongser at web.de>
wrote:

>  Dear Dean,
>
> It appears that the parameters for the WHO PM2.5 standard is 2mg/min of
> _what_ _burning_ _level_ (i.e., we need a wattage parameter of some type)?
> When an Italian university study concluded that an average unfiltered
> cigarette at human-puffing speed (i.e., smoked in around 5 minutes)
> produced more particulate than a modern, properly running 250KW diesel
> engine fully loaded for an hour, it is important to link those 2 mg with an
> amount of fuel combusted in that minute, don't you agree? What is that
> parameter? Crispin obliquely referred to this earlier along in this
> discussion by saying to decrease particulate you just have to go to a
> smaller stove. There is a limit for every stove "bore" below which clean
> burning (however that's defined) will not be maintainable. And with
> airspeed (pressure differential), it's the same thing, there is an upper
> limit at which you will have excess air for a given bore.
>
> Well-made charcoal left that particulate somewhere else-- in spades --
> probably in the air.
>
> regards,
> Ron
> P.S. Somehow I seem to be getting a feeling that the WHO standard is not
> being chosen for proven health purposes, but rather for certain types of
> fuels to be ultimately shown to be  by definition "too dirty".
>
> On 25.05.2015 17:12, Dean Still wrote:
>
> Hi Alex,
>
>  The best TLUD with a fan patterned after the Tom Reed design, using a
> clean burning brand of heating stove pellets, started with alcohol gel,
> seemed to do better than the new WHO standard of less than 2mg/min of PM
> 2.5. But most well tuned TLUDs we test are approximately around 4 to 10.
> And the untuned TLUD, of course, can be much worse. This is from
> gravimetric testing which catch a lot more PM2.5 than light scattering
> tests. The ISO/IWA requires gravimetric testing.
>
>  Well made charcoal burns without significant emissions of PM 2.5 and a
> charcoal stove met the WHO PM2.5 standard.
>
>  Using 'real wood' is a bigger challenge. Not as clean yet. But dedicated
> TLUDers are experimenting diligently!
>
>  Best,
>
>  Dean
>
> On Sun, May 24, 2015 at 11:18 AM, alex english <aenglish444 at gmail.com>
> wrote:
>
>> Torrified wood has most of it's volatiles.  I would expect the gases to
>> have a higher CV and wider range of flame stability when used in a premix
>> burner. Just guessing this has no relevance to cooking stoves.
>> Dean, what is the range, cat pee best to worst PM emissions, that you
>> have measured from any and all tluds when burning dry wood pellets?
>> Alex
>> On 2015-05-24 1:53 PM, "Dean Still" <deankstill at gmail.com> wrote:
>>
>>> Dear Ronald,
>>>
>>>  Thanks for your helpful comments. Charcoal without remaining wood in
>>> it doesn't make smoke but, of course, wood really likes to smoke. With
>>> biomass the preparation including recipe, drying, pellet size, etc. makes a
>>> big difference in emissions when trying to get down to the very low levels
>>> needed to protect health. I'm making some torrified pellets and will report
>>> back after testing under the hood.
>>>
>>>  All Best,
>>>
>>>  Dean
>>>
>>> On Sat, May 23, 2015 at 3:52 PM, Ronald Hongsermeier <rwhongser at web.de>
>>> wrote:
>>>
>>>>  Dear Dean,
>>>> I may seem like I'm harping here, but now that you've said a bit more,
>>>> you've mentioned a couple of factors that I have noticed in my limited
>>>> experience without a hood and therefore without concrete parametric
>>>> analysis, but for which I can give some postulates.
>>>>
>>>> 1. The wood-gas stove in design mode depends on a uniform fuel
>>>> "chunk-size" which promotes a level "pyrolysis" front(planar) migrating
>>>> towards the bottom of the stove. If that plane is broken by dis-uniformity
>>>> in the fuel or overly large gaps between the fuel pieces, you will get a
>>>> spot drop in temperature along with glowing fuel which will migrate
>>>> unevenly towards the bottom of the stove, breaking the pyrolysis front and
>>>> sometimes dropping the mean temp inside the burning chamber such that the
>>>> rising wood gas will no longer be close enough to critical temp that the
>>>> onset of 2nd-ary air will ignite it.
>>>>
>>>> 2. 1. would be consistent with the bark observation. Bark generally has
>>>> lots more minerals and less energy per unit mass. Did you/they assure
>>>> dryness level of the bark? Were the pieces between (cross-section/10-20) of
>>>> the stoves throat? Do you mean pellets from eucalyptus wood or when
>>>> eucalyptus oil is poured on the fuel? Off the shelf kerosin burners here in
>>>> germany are strictly regulated as to what you may or may not burn in them.
>>>> If it is smoking it is either wrong fuel, design flaw or user error.
>>>>
>>>> 3. Pellets pack closely, so if they are smoking, usually the problem
>>>> can be fixed by either turning up the fan a bit or putting some chimney
>>>> length between the secondary air and the pan to increase the draw. (i.e.,
>>>> the primary air is probably not of sufficient pressure to deliver enough O2
>>>> to the pyrolysis front to keep it hot enough such that it will ignite upon
>>>> contact with the secondary air.)
>>>>
>>>> 4. Because torrefied pellets are partially reacted, they may be
>>>> somewhat less dense and especially because the ends will be cleaner, they
>>>> may not resist airflow as much, which may help somewhat with 3. above. I
>>>> would expect them to act very similar to dry pellets, except for the
>>>> difference in density.
>>>>
>>>> regards,
>>>> Ronald von Aftermidnighttimeforantibiotics (and bed)
>>>>
>>>>
>>>>
>>>>
>>>> On 23.05.2015 23:49, Dean Still wrote:
>>>>
>>>> Dear Ron,
>>>>
>>>>  We had three women interns here at the research center for a summer
>>>> who found cleaner burning recipes for the TLUDs gathered from the
>>>> surrounding forest. Some things like bark make smoke, etc.
>>>>
>>>>  Many pellets smoke when using eucalyptus, etc. Different mixtures of
>>>> kerosene make more or less smoke in off the shelf stoves.
>>>>
>>>>  I'm wondering if torrified pellets will burn cleaner than normal
>>>> pellets.
>>>>
>>>>
>>>>  Best,
>>>>
>>>>  Dean
>>>>
>>>> On Sat, May 23, 2015 at 1:28 PM, Ronald Hongsermeier <rwhongser at web.de>
>>>> wrote:
>>>>
>>>>>  Hi Dean,
>>>>> I remember that there was a proposed university program (W. Virginia
>>>>> or the Carolinas??) In view of the deaths(not _many_ but tragic) that have
>>>>> taken place due to off-loading of pellets at some European ports (CO in the
>>>>> hold) The torrefaction could lead to a more inert fuel. That's hopeful
>>>>> speculation on my part however. You would be transporting some less bound
>>>>> water and the energy density is better than regular pellets in addition to
>>>>> the lack of liquid or vapor H2O absorption issue mentioned before-- these
>>>>> would lend efficiencies in the logistics end of things and an even more
>>>>> uniform fuel than regular pellets, which tend to absorb quite a  bit of
>>>>> water here in the damp winter weather...
>>>>> I have to admit that I'm a bit puzzled as to what you mean by cleaner
>>>>> fuel recipes. What specific pollutant are you interested in or are you
>>>>> talking about particulate?
>>>>> If you aren't choking the burn by putting the pot too close, you
>>>>> should be getting a very clean burn with a TLUD?!?
>>>>>
>>>>> regards,
>>>>> Ron
>>>>>
>>>>> On 23.05.2015 22:01, Dean Still wrote:
>>>>>
>>>>> Hi Ronald,
>>>>>
>>>>>  I'll keep looking. I think that we shouldn't forget cleaner fuel
>>>>> recipes as part of the solution.
>>>>>
>>>>>  Best,
>>>>>
>>>>>  Dean
>>>>>
>>>>> On Sat, May 23, 2015 at 12:33 PM, Ronald Hongsermeier <
>>>>> rwhongser at web.de> wrote:
>>>>>
>>>>>>  Hi Dean,
>>>>>> I did some searching around on the internet several years ago on this
>>>>>> topic.
>>>>>> I'd like to try torrefied stuff as well, but I struck out at that
>>>>>> time.
>>>>>> No idea where to find them.
>>>>>> The main advantage that I picked up on at that time was that they
>>>>>> should be relatively inert as to picking up extra water after they were
>>>>>> pelletized.
>>>>>> Cleaner burning than what?
>>>>>> clean burning is a control issue, not a fuel issue as far as I
>>>>>> understand. If I understand the concept correctly, it's like using part of
>>>>>> the large molecules initially broken out (cracked) by the heat in the
>>>>>> reaction vessel to coat the surfaces of the remaining unpyrolized material.
>>>>>> This should burn quite okay in a TLUD.
>>>>>>
>>>>>> regards,
>>>>>> Ronald von Nasennebenhöhlenhölle (but I'm coming back)
>>>>>>
>>>>>>
>>>>>> On 23.05.2015 20:56, Dean Still wrote:
>>>>>>
>>>>>> Hi All,
>>>>>>
>>>>>>  I'd like to try torrified pellets in a TLUD under the emissions
>>>>>> hood.
>>>>>>
>>>>>>  Any ideas on where to find them?
>>>>>>
>>>>>>  Or if it should be cleaner burning?
>>>>>>
>>>>>>  Best,
>>>>>>
>>>>>>  Dean
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Stoves mailing list
>>>>>>
>>>>>> to Send a Message to the list, use the email addressstoves at lists.bioenergylists.org
>>>>>>
>>>>>> to UNSUBSCRIBE or Change your List Settings use the web pagehttp://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/
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Stoves mailing list
>>>>>
>>>>> to Send a Message to the list, use the email addressstoves at lists.bioenergylists.org
>>>>>
>>>>> to UNSUBSCRIBE or Change your List Settings use the web pagehttp://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/
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Stoves mailing list
>>>>
>>>> to Send a Message to the list, use the email addressstoves at lists.bioenergylists.org
>>>>
>>>> to UNSUBSCRIBE or Change your List Settings use the web pagehttp://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/
>>>>
>>>>
>>>>
>>>
>>> _______________________________________________
>>> 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/
>>>
>>>
>>>
>> _______________________________________________
>> 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/
>>
>>
>>
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email addressstoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web pagehttp://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/20150525/528bf3b6/attachment.html>