[Stoves] Lower PM in TLUDs than in stoves with fans

[Paul Anderson]

Stovers,       (and sent to my www.drtlud.com   Webmaster who can place 
this on my website, but comments will be answered via the Stoves Listserv.)

On 8/28/2013 10:56 PM, Dean Still wrote:
> ......
>
> Jim Jetter reports that a TLUD can have fewer fine particles compared 
> to fan stoves. We're finding the same thing.
>
It is time to get serious about how TLUD stoves have superior 
performance.   Finally we are getting lab testing data.   Well, not 
really.   We are getting "statements" but the data sets are not being 
presented to us.   That is okay.   We can wait for Dean and Jim and ALL 
OTHER STOVE TESTING CENTERS to provide some data. Let's just use the 
above statement as the basis for my comments here.

1.  "Fan stoves" is a BAD name.   Any stove with a fan can be a "fan 
stove".   What Jim and Dean are discussing are stoves that include 
Oorja, Biolite (two models?), Philips, Reed Woodgas Campstove, maybe 
some units from China.   At least THREE different combustion regimes are 
included in the above named stoves.   But Who knows which ones they are 
talking about?   THEY know, but protocols etc are preventing the data 
results from being given, even with or without the names of which 
stoves.   But we do know that they have fans. But so do some other stoves.

2.  "Stoves with fans" is also not sufficiently specific, but at least 
they could be recognized for what they are, which is, stoves of 
different types that have fans.

A.  They could be "Rocket stoves with fans" as in the Biolite Home stove 
and maybe something (prototypes perhaps?) from Envirofit or Stove Tec.

B.  They could be "Fan-jet stoves with fans" (or some other name, but 
this is what I have called them for several years).   These are stoves 
with intense, forceful mixing of air deep into the fuel chamber.   These 
include the Biolite Campstove, Philips stove, the WorldStove Lucia-FA 
(forced air), and the Turbococina of El Salvador.   These are (perhaps) 
related to pellet-stoves as sold in North America in which the intensity 
of the jets of air consume small quantities of pellet fuels in a small 
cup-type combustion chamber.   For sure these are NOT TLUD stoves.  They 
can well be micro-gasifier stoves.   They can certainly be highly 
regarded. But they are not the only stoves with fans.   And to call them 
"fan stoves" is unclear and unfair to the other types of stoves that can 
have fans.

C.  They could be "Simple Improved Cookstoves - ICS - with fans". 
Something like a bucket-stove with a fan blowing onto the flaming fuel. 
   No examples come to mind, but add a fan and have a "fan stove."

D.  They could be "TLUD stoves with fans".   Yes, TLUD stoves can be 
operated with fans.   The opening statement is referring to natural 
draft TLUD-ND having less  PM than TLUD-FA.     TLUD-FA stoves include 
the Reed Woodgas Campstove, the Oorja stove, the Belonio/Olivier rice 
husk gasifiers, McLaughlin's Joy-to-the-World, and my 2004 prototype 
"Juntos B"  (which is described in the 2004 paper   "Biomass 
Gasification: Clean Residential Stoves, Commercial Power Generation, and 
Global Impacts (available at 
http://www.drtlud.com/resources/publications-and-multimedia/psa-catalogue/ 
).   And there are probably other TLUD-FA units.

3.  So, one study that needs to be done is to compare the PM from 
TLUD-ND and TLUD-FA.   Do such results already exist?    Do we need to 
wait very long for these results?   I ask these questions to those who 
have the capabilities and the financial resources to conduct those 
tests.    You know who you are.   Ongoing budgets and some major grants 
have been given for capabilities to conduct these types of tests.   And 
it is not just EPA and Aprovecho who get such funding.   But some grants 
prevent the dissemination of results until much later.

4.  BUT.   Yes, there is a BIG BUT to be considered.   This is because 
TLUD-FA (those with fans) have been blatantly mis-used and the test 
results could be erroneous because the test was not stopped when the 
TLUD pyrolysis process stopped, which is when the bottom burning of char 
started and continued as long as operators were feeding in raw fuel at 
the top.

I repeat:  the TLUD testing needs to be _/stopped when the TLUD 
pyrolysis process stopped, which is when the bottom burning of char 
started and continued as long as operators were feeding in raw fuel at 
the top. /_

[[   I have already prepared a short document about this and will post 
it soon. ]]

In conclusion, let's get our understanding clear that the addition of a 
fan to a stove does NOT automatically put that stove into the Tier 3 and 
Tier 4 categories of low PM emissions.   FIRST think of what kind of 
combustion the stove utilizes:   simple ICS, Rocket, TLUD, other 
micro-gasification, other ....    THEN consider if it has a fan in it.

In biology, first the animal type, and then if it flies or not: Birds 
fly (but not all of them);   Many insects fly;   some pre-historic 
reptiles could fly;   and some mammals (bats) can fly.   Flying is 
important, but Phyla is more important.   Fans are important, but not 
more important than the combustion regime.

STATEMENT:  I believe that the TLUD stoves (whether ND or FA) are 
cleaner about PM than the other combustion regimes because the process 
of pyrolysis leaves the inert materials (non-combustibles known as ash) 
held tightly to the charcoal that is created.   So, do NOT burn the 
charcoal.   Especially do not burn it with vigorous streams of air at 
the level of the charcoal.   [And there are probably additional 
variables to be studied.]

This hypothesis remains to be proven.   But while we wait for the test 
results, money will be channeled to other stove technologies, field 
tests of health will be conducted withOUT having a TLUD stove included 
in the study, and people will continue to suffer (and some will die) 
because of the high PM levels in household cookstoves.  It is late 2013 
and studies of TLUD stoves are only scratching the surface of what 
things need to be studied.

Oh well, better this progress than less progress.   And all of the TLUD 
enthusiasts are certainly willing and eager to join into any and all 
efforts.

Paul

Paul S. Anderson, PhD  aka "Dr TLUD"
Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
Website:  www.drtlud.com


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