[Stoves] Efficiencies for the rich and poor.

[Jock Gill]

Ron,

I suggest that we have to have different Metrics for efficiency determined by what the goal is in a given local situation.

So, a rocket stove may be the most efficient way to boil water with less wood?  But terribly inefficient at making charcoal.

On the other hand, if harvesting charcoal is a principal goal, then a good TLUD is probably the most efficient way to do that.

Of course both technologies need to provide clean burning, low particulates, ease of use etc.

I would also set a goal for as close to zero soot on pots used for cooking, or boiling water as possible. Soot on pots is, as I understand it, an indicator of inefficient and incomplete use of the CO in the biogas produced by both combustion and pyrolysis.

Clearly, one set of metrics will NOT properly fit both combustion and pyrolytic solutions.  Isn't it time to agree that there are appropriate uses of both technologies, given local conditions and requirements, and that neither one is intrinsically "better" than the other?

It is a waste of time to get into pissing matches as to who has the "best" universal solution.  There's simply isn't one.

Cheers,

Jock

Jock Gill
P.O. Box 3G 
Peacham,  VT 05862

Cell: (617) 449-8111

:> Extract CO2 from the atmosphere! <:

Sent from my iPad

> On Oct 3, 2013, at 11:56 PM, "Ronal W. Larson" <rongretlarson at comcast.net> wrote:
> 
> Frank:
> 
>    The folks working with char-making stoves are not going to understand this sentence at all:     'We do not need to determine the char left in the stove. '
> 
>     That is as simple a measurement as you can find.   Granted that most of the weight loss is before 450 C,  the weight is NOT constant as you keep going higher in temperature   You will have a fair shot at the temperature achieved by measuring the weights in and out.  But temp is not the only variable, there is also the time at temperature, the size of the fuel etc.  See material in the Gaur-Reed Chapter 8.
> 
>    I know people are trying hard to determine the peak pyrolysis temperature from the characteristics of the char - besides weight differences, there is density, water-adsorbing properties, pH, and electrical conductivity in the "simple" (poor man) category.  Some big changes in conductivity can occur above a certain temp.   Many people would like to know the CEC characteristics, but I know nothing on that measurement.
> 
>    I guess I am saying that the stove itself might serve as the "pipe" you are describing.  If you have a good guess at the temperature of the produced char, you have a reasonable estimate of its remaining energy content, which is what I guess you are after.   I don't have much hope that any test with a "pipe" is going to tell you much about a particular stove.
> 
>    But mainly, I urge you to keep measuring the weight of the char.  You will not understand much about a char-making stove if you don't know the weight of the produced char.
> 
> Ron
> 
> 
> for more Biomass Cooking Stoves,  News and Information see our web site:
> http://stoves.bioenergylists.org/
> 
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