[Stoves] Classifying biomass fuels - topic change

Dean Still deankstill at gmail.com
Sat May 30 11:14:53 CDT 2015


Yes, Cecil:

The operation of the stove effects fuel use and emissions.

Yes, the fire under the veranda, especially if it's windy,
exposes the cook to lower levels of emissions compared to a closed kitchen.

The stove with close to 100% combustion efficiency is also a big help.

A pot with a pot skirt helps.

So does an almost smokeless fuel.

A stove with a functional chimney protects health here is the USA.

The stove with over 45% heat transfer efficiency uses a lot less wood to
cook, etc.

How about opening the doors and windows in the closed kitchen or using a
smoke hood, etc?

Aren't we investigating, testing, making available a long list of
effective, lowest cost interventions which may be coupled together?

Best,

Dean





On Sat, May 30, 2015 at 7:14 AM, <cec1863 at gmail.com> wrote:

> Dear Frank and anybody else,
>
> What I struggle with is why get so precise about the different types of
> fuel going into the stove when the human factors of how the stove operator
> prepares the biomass fuel before ‎and how they habitually operate the stove
> have more influence on the efficiency and emissions and cooking performance
> than the characteristics of the biomass fed into the stove. The fuel is a
> cultural product which is constructed by drying and chopping and mixing and
> then their is the rate at which this fuel is fed into the fire. The
> variation in the human factors is huge when the stove's fuel supply does
> not lend itself to standardization because it has to be humanly constructed
> from nature and the nearby environment..... and the operation of the stove
> cannot be  automated as is the case with electric kettles and rice cookers
> and gas stoves and ovens with thermostat controlled automatic fuel feeds
> and timer switches.
>
> Cooking with a 3 stone fire stove is a culturally constructed performance
> where the stove operator acts exactly like the conductor of a symphony
> orchestra who knows what cooking experience (qua sounds) he or she wants
> their  stove (qua orchestra) to produce.  ‎The fuels are operated
> culturally by the cook to get the performance (qua cooking experience)
> wanted by selecting and combining the different fuels on hand in real
> time.....thinking about this process again it is more like improvised music
> such as a jazz quartet or sextet where the melody gets played by
> spontaneously combining ‎and modulating the different instruments (fuels)
> available at a particular session (cooking episode). All unautomated
> cooking is a free syle performance....ever been in a kitchen in a Chinese
> restaurant? There cooking is a masterful performance in time because mostly
> the power is on high and the cook varies only the time, ingredients, the
> stirring of the ingredients and the moisture content of the dish being
> "blow torched"!
>
> Returning to the topic of how to characterize the different fuels and the
> role played by the fuel preparer as highly variable cultural performances
> in its own right (how long it dries, the size of the pieces into which
> larger pieces of biomass are split or chopped) in a hugely more variable
> culturally constructed stove operator\stove\fuel\pot performance....to my
> feeble mind the variability in the human factors seems to over power the
> technologically automated part of basic stove operation and cooking with
> natural draft stoves by which I mean the following: the way the stove is
> operated or misoperated by the stove user has more influence on its
> emission and efficiency performance than the stove technology itself does.
>
> If my proposition is true that small household stoves are inherently
> operator dependent technologies then it follows that operator training and
> the culure of stove operation are probably inherently more powerful
> determants of emission and efficiency proformance ‎than the automated
> effects of the stove technology itself.A careful cook in a poor household
> will achieve wonders with a 3 stone fire which will be hard to impossible
> for an improved stove to compete with including emissions inhaled if the
> kitchen is under a tree or in a separate kitchen shelter.
>
> So give culture and human factors the respect they deserve - say 50% of
> the variability. That part of the variability is the responsibility of the
> stove operator although in some stoves it is no doubt much less! My beef is
> that the variable and learned human factors responsible for - say - up to
> half of the performance variation deserve as much attention as the
> automatable parts of simple domestic stoves. Why? Because mostly the techno
> fixes are expensive, finneky, and - you heard it from me - still highly
> dependent on the stove operator learning how to operate a technologically
> fixed and "improved" stove properly. Ultimately all new technos must
> learned and mastered to operate it properly.
>
> So give learning and the cultured ethno-science of solid fuel domestic
> stoves it's due! All said it may be useful to test stoves by spcifying
> fuels and then operating them differently on purpse to establish the
> positive to negative variation in performance: (1.) expertly operated  (2.)
> expertly misoperated, (3.) average operated (not too hot and not too cold
> but just right). That becomes a test of a stove's technological limits and
> to quantify the human role of operator in stove performance. What are the
> mimimum skill that an operator must master to even get the stove to
> function (to turn it on\light it)? What are the skill levels reqired to get
> the stove to deliver 30% of its potential efficiency and emission benefits?
> 60% of potential benefits? 90% of potential benefits. Now it becomes
> possible to compare new improved stoves in terms of how easy or difficult
> the are to master to get "x" absolute improvement in efficiency and
> emissions!
>
> Now it is perhaps possible to see where I am going with my walk about.
> Hope it was useful.
>
> In search and service,
> Cecil Cook
> TechnoShare SA
>
> Sent from my BlackBerry 10 smartphone.
>   *From: *Frank Shields
> *Sent: *Saturday, May 30, 2015 1:59 AM
> *To: *Discussion of biomass cooking stoves
> *Reply To: *Discussion of biomass cooking stoves
> *Subject: *[Stoves] Classifying biomass fuels - topic change
>
> Dear Cecil, Stovers,
>
> I think the classes we need are:
>
> 1) size and shape
> 2) bulk and particle density
>
> Then on non-wood materials. On vegetative grasses, leaves like  or nuts
> and like products we need:
>
> 3) Lipids (add dry biomass to a beaker and petroleum ether / heat / filter
> and evaporate the liquid and weigh the residue.
> 4) Sugars etc: Take above sample / add water / boil / filter and dry
> liquid fraction and weigh the residue.
>
> On woody materials omit the lipids and water soluble steps. Likely too low
> a concentration to bother with.
> 5) Ash percent
> 6) moisture percent
>
> Now we have left the cellulose, hemi-cellulose and the lignin that are not
> easy tests and I think we can find a method that will work without testing
> for each.
> Perhaps the following:
>
> TGA to measure E450c volatile fraction (or using a pipe) will be enough
> calculated lipid free and sugar free and DAF basis. Call it LS-DAF.
>
>
>
> Cecil - Your suggestion of collecting biomass fuels at a specific site for
> testing. I suggest the above tests and determine the range of each
> parameter we find from the fuels on site. Then the fuels are tested in
> stoves to come up with working range of each parameter for each of the
> stoves. Something like that.
>
> Regards
>
> Frank
>
> Frank Shields
> franke at cruzio.com
>
>
> On May 29, 2015, at 4:41 PM, Cecil Cook <cec1863 at gmail.com> wrote:
>
> Dear all,
>
> Surely there are ways to minimize this particular source of variation.For
> example, we get a random mixed sample of all the different kind of biomass
> used in a particular target community- some of everything they burn or even
> a quantitatively structured sample -  of types of biomass and moisture
> contents and we use that as our test fuel.  Also, we need to check how well
> the Improved Stoves perform in the rainy season when everything gets damp
> and the moisture content goes much higher.
>
> The veratility of a stove - namely its capacity to burn a large number of
> different types of biomass fuel typesmay be one of the mot valuable
> characteristics in a biomass scarce environment or with low income urban
> dwellers.
>
> That's my two cents worth,
>
> Cecil sweating in San Marcos Tx and treading water as well
>
> On Fri, May 29, 2015 at 6:16 PM, Frank Shields <franke at cruzio.com> wrote:
>
>> Dear Paul, Crispin, and Stovers,
>>
>> “finding good publications on stoves” Many good publications for others
>> but none for us because we don’t yet have biomass fuels classified into
>> relevant classes suitable for us to predict how well a specific stove will
>> respond with a specific fuel. Therefore, until this is done, publications
>> comparing stoves means -nothing- to us. Perhaps there will be information
>> in the articles useful for others.
>>
>> Crispin writes; "compare the fuel-stove combinations. And that has only
>> recently been done”.
>>
>> It has never been done. We don’t yet know how to do it. Only the three
>> interns started working on finding what the characteristcs biomass have
>> that might be useful to study.  Then we need to determine the Working Range
>> we need for the results and the appropriate test procedure needs to be
>> developed to get within that range. We need to develop some ‘spider graph’
>> or something to illustrate where the fuel falls into and another telling
>> where the ranges the stoves fall into. These are both physical and chemical
>> properties.  It is possible and should be keeping us busy for a while.
>>
>> regards
>>
>> Frank
>> Intern 1
>> Intern 2
>> Intern 3
>>
>> Frank Shields
>> franke at cruzio.com
>>
>>
>> On May 29, 2015, at 2:01 PM, Crispin Pemberton-Pigott <
>> crispinpigott at outlook.com> wrote:
>>
>> Heh heh, Frank
>>
>> OK, let me extend it:
>>
>> "There can be no (useful) comparison between stoves until we compare the fuel-stove
>> combinations. And that has only recently been done in a systematic manner.
>> This being that a culturally relevant task is being used and the stove
>> is claimed to be designed for that task and that fuel and moisture level.
>>
>>
>> “Useful” = Our PURPOSE of developing better stoves is to improve Real
>> World situations hence the critical requirement to include the context
>> of use in all comparative testing. Fuels to study need to have the same
>> characteristics as site-specific Real World fuels. Using any other in a
>> comparison is a waste of time.
>>
>> >Only four people in the World realize this;
>>
>> Well…that might be slightly unfair. Every cook who buys and uses a stove
>> knows this. It would be more reasonable, if we are going to generalise, to
>> say that people who do not use these stoves and who mostly work in offices
>> in the Western World, do not realise this.
>>
>> But generalisations are usually wrong, right?
>>
>> Regards
>> Crispin
>>
>>
>>
>
>
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