[Stoves] No subsidies in TLUD char peoduction
Ronal W. Larson
rongretlarson at comcast.net
Thu Dec 7 06:06:55 CST 2017
Julien, cc List
Apologies. I hope anyone thinking of responding to my message from about 6 hours ago will respond to this one instead.
1a. Re my first comment on using concrete instead of metal for the inner cylinder: I had not thought that through well enough. With a concrete or ceramic inner cylinder replacing the present one, there would be much less heating of the secondary air which is flowing upward between the two cylinders. Newcomers to TLUD design may not have noticed that the lowest concrete cylinder had a ring of “notches” of maybe 5 or 10 sqcm. Those were the entry points for the essential secondary air - which is much more valuable if hot - and that heating is obtained at essentially zero cost in this nice Bangladeshi design.
1b. Long time members of this list will know that there has been a lot of discussion of testing and design improvement using throw-away tin cans. The steel reactor cylinder being used here (with “24 small holes”) probably is thicker than those of (say) the (largest common) #10 tin cans (which are about 6”x9” (roughly 15 cm * 22.5 cm)). It looks like the present metal cylinder can be readily removed. It might be (not sure) that there are enough #10 tin cans being scrapped in Dacca to justify the difficulty of cobbling together a loser-cost inner cylinder that might work almost as well, but allow a lower selling price (with not too frequent future replacements?). Just needed to get this in because that #10 tin can is such a marvel of modern society. It can’t cost food companies much more than 25 cents - and it is strong (difficult for amateurs to cut).
2. Re my second comment below: I also screwed up by not saying more on the words “blue biochar”. There is a lot more literature on the term “blue carbon” - generally meant in the climate literature to be shorthand for mangroves. This is a marvelous tree able to thrive in salt and brackish water. I don’t know if there is a way for Bangladeshi Akha-using communities to acquire rights to growing and harvesting their own designated tidewater hectare - but perhaps the Akha team can find a way. Villages could be assigned their own off-shore regions, to be relinquished if not used. Some rationing of this “land” might become necessary if the idea has merit.
There are three types of mangroves, each best for declining salinity., as one moves inland. Along with some reeds, there is not much else that can grow on this “land” that I believe Bangladesh considers it has an excess of.
Managing these trees for energy could possibly double their usual annual output (coppicing/pollarding rather than cutting down entirely) - and they of course are wonderful anyway for protecting inland property against storms, and are much needed for the young of some fish.
The above would seem easier to manage that applying the word “blue” to waters too deep for mangroves, but there may be some other reasons to prefer kelp. I am NOT giving up on the deeper waters off Bangladesh - as there is a lot more ocean area available where mangrove culture couldn’t occur.
3. I’d also like to start a rumor that I was the person who stole the bag of charcoal. This so that Julien is not himself accused of this brilliant way to advertise the merits of biochar and the Akha stove.
Ron
> On Dec 6, 2017, at 10:55 PM, Ronal W. Larson <rongretlarson at comcast.net> wrote:
>
> Julien cc List
>
> Thanks for the answers below. Good to hear that both users with and without land see value in making char. No new questions, two comments
>
> 1. Re a concrete inner cylinder, you said below “..but their smoke-free combustion was less reliable, and there were some gas burner issues to solve. “
> It is not obvious to me why either concern should occur, so I hope stovers everywhere could try this out. Seems likely to be cheaper (can even maybe cast in place) and hopefully longer lived. We know usual cheap steel has a limited life and the best steels are likely both not readily available and expensive.
> I forgot to congratulate on the two metal swinging “doors” at the bottom. Nice solution.
>
> 2. Re fuels, the biochar list has had quite a lot of recent discussion of “blue biochar” - where the source material is kelp or other seaweeds. Bangladesh is possibly already in that business, because of its ocean proximity. This could be a source of employment and a way to save forests while having a feedstock that should bring back needed minerals and fertilizer value. Beating the price of wooden blocks seems possible.
>
> Ron
>
>> On Dec 6, 2017, at 10:05 PM, Julien Winter <winter.julien at gmail.com <mailto:winter.julien at gmail.com>> wrote:
>>
>> Hello all;
>>
>> Thanks for you comments on the Akha-Biochar Project in Bangladesh.
>>
>> The cost and payback is not fully worked out, because it will take about a year for TLUD-biochar ecosystem to become established in community, and it will continue to evolve. The stove costs about $20 to make, this could be brought down as numbers of stoves increase. Also, we are still at the stove-prototype stage, so we can expect some modifications and fine tuning. Payback is developing, as farmers and gardeners discover the value of biochar for food production. We have "Farmer Biochar User Groups" that are conducting field trials, so they can learn from first-hand experience what biochar can do for them. There are also graduate students involved in gathering evidence to make recommendations on optimum application rates. It could take a couple of years at any one location for the local population to be able to place their own value on biochar, and what they are willing to pay for it.
>>
>> Whether people use the char themselves or sell it depends on their personal opportunities. There are many families that are landless. Presently, they see char sales as a way to earn cash or barter. They think that is a great idea; save fuel, cook faster, AND make biochar! People with land, especially farmers, see biochar as a way of making permanent improvements to the quality of their land, so expect that using biochar could have very substantial impact on their family's economic well being.
>>
>> I have been advocating using biochar in composting, or mixing it with manure before it goes onto the field. We need work on using it in human waste management.
>>
>> There is no shortage of good soil scientists and agronomists in Bangladesh to work on biochar technology.
>>
>> The outer concrete cylinder of the Akha stove is cast. We have made stoves with concrete reactors (lined with clay slip), but their smoke-free combustion was less reliable, and there were some gas burner issues to solve. That is not to say that concrete reactors will not work, but they need quite a bit of research and development, and a laboratory. Metal TLUD reactors, on the other hand, are well understood. About 24 small holes in the side wall of the metal reactor make the gasification of chunks of wood more reliable, and less prone loosing the gas flame. We use cast concrete (rather than clay) because it is easy to get concrete rings with flat surfaces at the top and bottom. The concrete components are made specifically for the Akha. There are many small business around who can cast concrete.
>>
>> Mahbubul has been working with different ratios of Portand cement, sawdust and biochar dust in the concrete. The more organics, the lower the heat capacity and heat conductivity of the stove body. Micro porosity is supposed to make concrete more resistant heat by providing spaces for minerals to expand into. Obviously there is a trade-off between adding organics and strength of the concrete. Different recipes are being tested in the field. It is all trial and error.
>>
>> Mahbubul has also worked with local ceramic artisans to make the massive stove components from clay. There very skilled people to work with, and kaolinitic clay, so ceramic components are possible. The more metal components on the stove that we can replace with ceramics the better, because all metal in Bangladesh is imported.
>>
>> The Akha is about 25% more efficient than a traditional stove. The Akha has gone through a water-boiling test at a laboratory in Dhaka, and was about 30% efficient at getting energy from wood into the water. The main view that the Akha saves 25% of the wood comes from household feedback. That is what the women tell us.
>>
>> The Akha-Biocahr Project has funding for its current intervention until 2019. It is enough to see if the TLUD-biochar technology will take root. If it does, then the technology may spread all by itself as local entrepreneurs see an opportunity. In fact, I think that if these technologies viable, then they will out of our control and unstoppable. The 'market' is 25 million homes. All the same, I am trying to raise money so that Mahbubul and crew remain as proponents and stakeholders in what they started. There is work to be done in developing compressed fuels, because there is not enough wood in the country. We need to monitor the impact on forest cover, and make sure that poorest households don't become energy-starved if the price of wood goes up.
>>
>> One other thing that will push TLUD-biochar technology forward is that sea-level rise could flood a third of the country, so soil productivity needs to increase.
>>
>> Cheers,
>> Julien.
>>
>> --
>> Julien Winter
>> Cobourg, ON, CANADA
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