[Stoves] Alternative to charcoal

[Alex English]

Crispin,
Do you think it is useful to place a value on the reduced life span of a 
$5 TLUD  when burning char compared to the same TLUD not burning the char?
Alex

On 08/04/2013 9:30 PM, Crispin Pemberton-Pigott wrote:
>
> Dear Dale and Friends
>
> The analysis of alternatives to charcoal should include the reasons 
> why people prefer it, strongly, over wood when given a choice of 
> either, with charcoal costing much more than wood per kg. Working out 
> theoretically how to burn all the wood (which is what burning 
> gases+burning char is doing) doesn't really address the reason why 
> people don't want to burn wood if they have enough money -- in other 
> words if they have a choice.
>
> Once it is admitted that burning wood gas then char is the same as 
> burning whole wood as far as the forest is concerned, we can also 
> admit that transport and convenience have a lot to do with it. In 
> other words, this is a question strongly influenced by social questions.
>
> The transport of charcoal (MJ per ton-mile) is much cheaper than 
> transporting wood and this difference dominates the charcoal economy. 
> It is impractical to ship wood 600 km in Mozambique because of cost of 
> doing so.
>
> In order to get the comparisons right I feel we need to agree on some 
> definitions. The wood can be dried in the field. The energy content 
> can be taken to be about 15 to 16 MJ/kg. Charcoal can be taken to be 
> 29 MJ/kg or about double the energy. Mental arithmetic becomes easy.
>
> Decent charcoal production (improvement of the source technology, not 
> only the stove technology) should be considered because it is a heck 
> of a lot cheaper to improve the production than to improve every 
> single stove in all sizes everywhere). What I mean by this is that if 
> we seek systems type improvements we should consider all the systems 
> involved. In a way it is like the 'open fire' as the baseline. It does 
> not help the analysis to seek really bad examples of open fires then 
> compare the 'improvement' to it.  Just a caution.
>
> One way to analyse this is to look at how the biofuel energy supply is 
> already emerging. The shipping of wood pellets and torrefied wood 
> shows there are ways to attract 'custom' selling packaged energy. A 
> stick of wood is a package of energy.
>
> I want to add one comment about the cost of the products. I tested 
> recently a TLUD pellet burner that by opening a small door, burns the 
> charcoal afterwards. The gas flame was not as controllable as the 
> charcoal one but that is a quibble. There was no need to transfer 
> anything, it was just a sequential burner. The market price is $5.50 
> and the production cost is $2.20 or so. That is with a metal shell. 
> With a clay shell it would be about $1.40 to make. I think that is 
> cheap. I will process the test results to see what the performance in 
> numbers was like.
>
> Pellets are a processed fuel and can include non-woody biomass. China 
> is making millions of tons of them from agricultural waste with an 
> aggressive expansion plan that include developing better and more 
> efficient equipment. That may be the charcoal replacement of the 
> future, provided people are willing to use them and the stoves deliver 
> the cooking and heating experience they seek.
>
> Regards
>
> Crispin
>
>     On 4/8/2013 4:09 PM, Andreatta, Dale A. wrote:
>
>         At the recent ETHOS conference Paul Means and Chris Lanning
>         gave a very thought-provoking talk about an alternative to
>         charcoal.  The basic idea was to use a gasifying stove with
>         prepared wood fuel. The prepared wood fuel would be bought by
>         the user instead of charcoal, and the supply chain would be
>         similar to charcoal.  The big advantage is that the very
>         inefficient step of charcoal production is eliminated.  The
>         stove would hopefully be easy to use and would smoke very
>         little, so as to retain the benefits of a charcoal stove.
>
>
>
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