[Stoves] The chemistry and metachemistry of stove emissions or health (Re: Crispin)

Traveller miata98 at gmail.com
Sun Oct 16 22:16:25 CDT 2016


Dear Mr Pemberton-Pigott: You must be joking. (I wish I could say, "I knew
Richard Feynman. Richard Feynman was a friend of mine. And you, sir, are no
Richard Feynman and may not joke around.)

Who really believes that "This is a high CO coal, that is a low CO
coal."? They need an education.

Emissions depend on combustion conditions. My free lesson is that children
should rot memorize it. Only when combustion conditions cannot be changed
can one speak of "low CO, high CO" coal for that particular application.

I remember "low-mid-high vol" coals, reflecting the hydrocarbon content.
One designs combustion chamber according to coal quality that is most
economically purchased over a 30-40 year life of a furnace of, say a power
plant. If coal markets change radically, one may change the furnace design
and other parts of a power plant to accommodate different coal chemistry
and see how one can change coal supply and transport contracts.

I do remember one instance like that in the US - around the time "acid
rain" legislation came to be passed. Some "low vol" coals, from some
counties in Pennsylvania and western part of Virginia, happened to be
low-sulfur. These coals were also ideal for coke preparation, but the
collapse of the US steel industry and softness in the coking coal (or "met
coal") market meant they did not command as big a price premium as they did
earlier.

It was generally believed that low-vol coals could not be used in power
plants, which were generally designed for the more plentiful mid- and
high-vol coals. However, some utilities - I think in Pennsylvania - started
testing low-vol coals in small shares and discovered that they could use
the low-vol coals without significant change in the furnace and plant
design, just changing some operations in order to use a blend that also met
the SO2 reduction requirements.

That is my vague recollection from around 1990-94. I worked on some "gassy"
mines in many states to develop Coal Bed Methane (CBM) projects.

"Fracking" gas was not yet on the horizon then.

In short, CO is not a property of coals. Those who believe otherwise should
be subjected to an RCT of their own CO intakes and performance of their
brains. I can propose some metachemistry hypotheses whose tests will be
subjected to meta-review by the super-human GBD folks.

Frankly, is this worth discussing? If fuel size influences combustion
conditions and economics, then sure, fuel chemistry and size need to be
considered together.

Or is the ISO IWA water boiling fixated on particular fuel chemistry range
and fuel size?

Nikhil


----------------------------


Message: 6
Date: Sat, 15 Oct 2016 13:44:37 +0000
From: Crispin Pemberton-Pigott <crispinpigott at outlook.com>
To: 'Stoves' <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] A breath of fresh clean air: "Contextual Design
        and Promotion of Clean Biomass Stoves" (ESMAP - Indonesia)
Message-ID:
        <YTOPR01MB0235B11607D4AB5BC31D1EA7B1DE0 at YTOPR01MB0235.CANPRD
01.PROD.OUTLOOK.COM>

Content-Type: text/plain; charset="utf-8"

Dear Nikhil

Thanks for the compliments to the team. I appreciate that you specifically
mention the context element as being an important facet of performance (not
just emissions). If a fuel supply is limited to large-ish hard trees
(think: rural Zimbabwe) cooks are not willing to split them into strips for
feeding into a stove. And that is that. Stick-fed stoves are rejected and
they go back to consuming 12-15 kg of wood per day.

That is a contextual mismatch: fuel size.

In support of preferred fuel:  I found out something interesting this week
which is that the sub-40mm coal in Kyrgyzstan is quite a bit cheaper in
rural areas than 80mm coal. The 80 is preferred ?because it burns longer?
but that is only because they have far too much excess air so the only
solution is to decrease the surface to volume ratio. In that condition ?
high EA and low surface/volume ? it is not possible to burn it cleanly or
completely.

Another aspect of the context is that people strongly believe that coals
have  inherent gases contained in them that come out. ?This is a high CO
coal, that is a low CO coal.?  That sort of thing. Obviously the stove is
an important contributor to any CO produced. If we have a stove that
requires a certain size of fuel (a TLUD, for example) then we are forced to
change that part of the context, something that may not succeed.

In support of ignoring preferred fuel:  A success story in this regard is
the Sumba Island salt maker which requires that the fuel be cut short
enough to fit into the stove, not left sticking out. The effort is more,
but the fuel saving is 70% so overall the effort is reduced. This provides
an incentive to adopt the far more efficient evaporating system (fuel is
purchased). They enthusiastically agreed the system was, on balance, much
better and offered to do the additional cutting.

The context includes anything that affects the family or the performance.
The CSI project was a clear, firm step in the right direction. Contextual
testing can assist the early decision process about what to permit and
promote. I received today two new tests from Java, numbers 457 and 458.
They are cranking them out very consistently. One of the new metrics, the
heat flux (cooking power per sq cm of heater pot surface) is a reasonable
predictor of acceptance or rejection by the market. One model (we don?t
pick winners) was recently dropped by the vendors because people complained
it was underpowered. That was obvious enough from the contextual test which
showed a gap between the number people require (2.7 W/cm2) and the
candidate stove (less than 2). In other words, ?we told you so?.

Now W/cm2 is not a water boiling metric is it? Well, yes it is, indirectly.
If I know the heating ability, expressed on that basis, I can tell you how
long it will probably take to boil any quantity of water in any size of pot
in that particular stove, using only a calculator or a set of curves on a
chart. Experiments showed this is true to within a minute.  This metric
frees the tester from having to use a certain pot size or certain amount of
water. In other words, it is a metric suited to all contexts.

In the referenced CSI Indonesia Pilot the funding is being used up as the
supply channels are filled and sales continue. Apparently people like the
approved stoves.  Except the one we thought was underpowered? ?

Very cool.

Regards
Crispin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20161016/fab1b262/attachment.html>


More information about the Stoves mailing list