[Stoves] Classifying biomass fuels - topic change

Sat May 30 09:58:08 CDT 2015

"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. " 

BRAVO, CECIL!!   Thank you for speaking for the poor. 

Rebecca Vermeer 

Eco-Kalan Project in the Philippines 
----- Original Message -----

From: cec1863 at gmail.com 
To: "Frank Shields" <stoves at lists.bioenergylists.org>, "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org> 
Sent: Saturday, May 30, 2015 7:14:22 AM 
Subject: Re: [Stoves] Classifying biomass fuels - topic change 

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: 

<blockquote>

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 

<blockquote>

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 characteristic s   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 

</blockquote>

</blockquote>

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