5 ms·

I want to see stoves that can burn wet wood, manure, fresh leaves, etc. It is clearly possible to do from a physics standpoint - but the trick is how to do it

I want to see stoves that can burn wet wood, manure, fresh leaves, etc. It is clearly possible to do from a physics standpoint - but the trick is how to do it in a robust, easy to use, and low particulate emissions way. High efficiency stoves also tend to be very hard to get lit - since they only really function when everything is at operating temperature. That problem needs to be solved - perhaps for example by storing gasified fuel from the previous use to start it next time.

akira2501 3y ago
Types of stoves in this study: Firewood. Charcoal. Ethanol. LPG. Pellets. In countries: Bangladesh. Mexico. Ghana. Nigeria. Kenya. Average home size: 4.2 people.
yetihehe 3y ago
Start with something more flammable than wet wood or with electric lighter. Burning wet wood and fresh leaves - it's more practical to dry them first with leftover heat from chimney. Otherwise they need high temperature.
- londons_explore 3y ago
  Sure. But it turns out that wood ideally takes multiple years to dry, and the vast majority of people don't collect wood from the forest 2 years in advance. (Think about the effective interest rate on your time - you are putting in effort 2 years before seeing the benefits). Instead, they collect wood 1 month before they use it (saving that 'interest'), and live with the fact their stove is a bit smokey. But they are unaware that their smokey stove is giving them lung cancer and making their family sick too. A stove design that could handle wet wood efficiently and without giving out deadly smoke would save a lot of lives and help the environment.
mattpallissard 3y ago
Stoves without a catalytic converter can burn wet wood, it's just that most of the heat goes out the chimney until the wood is dry. Also, where the inefficiency comes from. No way around heating water prior to combustion afaik.
- londons_explore 3y ago
  No, but you can recondense the water afterwards to get the energy back. Condensing boilers are commonly used for burning natural gas and petroleum fuels already. They just have a pipe out the side that dribbles condensate water. The problem with recondensing smoke from a wood fire is you tend to end up with lots of tar and end up with a sticky mess. However, if your burn hot enough with good mixing and the right air fuel mixture, that won't happen. Unfortunately that's hard to achieve without a computer monitoring temperatures and oxygen levels and adjusting fans etc. Which obviously makes your device much more complex, less repairable, and expensive.
tpm 3y ago
I don't want to see stoves. Like ICEs, they should be left in the past, for healthier and more efficient solutions.
- infecto 3y ago
  The majority of the underdeveloped world has no way to achieve that in the near term. The healthier more efficient solution is indeed higher efficiency fuel stoves. The great part of that is it can also spur new business with the help of NGOs/Governments/Funds etc. You get local businesses to make high efficiency stoves, subsidize for people who cannot afford, new businesses to make the fuel, thinking of things like charcoal or wood pellets (that one might be a little more complicated but still doable).
  - oblio 3y ago
    > The majority of the underdeveloped world has no way to achieve that in the near term. Why, though? Solar panels are becoming very cheap and induction stoves aren't necessarily high tech. Ikea makes this: https://www.ikea.com/us/en/p/tillreda-portable-induction-cooktop-1-zone-black-30546508/ https://www.ikea.com/us/en/p/tillreda-portable-induction-coo... Surely a cheap knock off could be made for $10-15 or something.
    - defrost 3y ago
      The link didn't appear to have the current draw .. but there's a very good chance it's high relative to a single solar panel or two in areas that lack reliable grid electricty. Hence the comment about the majority of the underdeveloped world and the near term. ( A key feature of much of the underdeveloped world is a general lack of IKEA kitchens with handy wall plugs and 24/7 high wattage grids )
      - oblio 3y ago
        > The link didn't appear to have the current draw .. but there's a very good chance it's high relative to a single solar panel or two in areas that lack reliable grid electricty. Product details -> Good to know -> Connection rating: 1800W. That's max power, I imagine they could run it at 900W, which, from what I see, would be 2-3 panels. Also, I don't think it's the "majority of the underdeveloped world". Based on this: https://www.statista.com/statistics/521212/number-of-off-grid-population-asia-africa-by-select-country/ https://www.statista.com/statistics/521212/number-of-off-gri..., to me those numbers look something like 20-30-40% of the population in these underdeveloped countries. Anyway, it's kind of a moot point, this will probably happen on its own over time, where it makes sense. > ( A key feature of much of the underdeveloped world is a general lack of IKEA kitchens with handy wall plugs and 24/7 high wattage grids ) This snark is irrelevant. I didn't say they should buy it from Ikea, ergo my comment about the $10-15 copycat (probably from Aliexpress). Nor did I say they should buy an Ikea <<kitchen>>. You can plug that thing on top of a $2 table to a regular wall plug or even an extension cord.

akira2501 3y ago

Types of stoves in this study: Firewood. Charcoal. Ethanol. LPG. Pellets. In countries: Bangladesh. Mexico. Ghana. Nigeria. Kenya. Average home size: 4.2 people.

yetihehe 3y ago

Start with something more flammable than wet wood or with electric lighter. Burning wet wood and fresh leaves - it's more practical to dry them first with leftover heat from chimney. Otherwise they need high temperature.

londons_explore 3y ago
Sure. But it turns out that wood ideally takes multiple years to dry, and the vast majority of people don't collect wood from the forest 2 years in advance. (Think about the effective interest rate on your time - you are putting in effort 2 years before seeing the benefits). Instead, they collect wood 1 month before they use it (saving that 'interest'), and live with the fact their stove is a bit smokey. But they are unaware that their smokey stove is giving them lung cancer and making their family sick too. A stove design that could handle wet wood efficiently and without giving out deadly smoke would save a lot of lives and help the environment.

mattpallissard 3y ago

Stoves without a catalytic converter can burn wet wood, it's just that most of the heat goes out the chimney until the wood is dry. Also, where the inefficiency comes from. No way around heating water prior to combustion afaik.

londons_explore 3y ago
No, but you can recondense the water afterwards to get the energy back. Condensing boilers are commonly used for burning natural gas and petroleum fuels already. They just have a pipe out the side that dribbles condensate water. The problem with recondensing smoke from a wood fire is you tend to end up with lots of tar and end up with a sticky mess. However, if your burn hot enough with good mixing and the right air fuel mixture, that won't happen. Unfortunately that's hard to achieve without a computer monitoring temperatures and oxygen levels and adjusting fans etc. Which obviously makes your device much more complex, less repairable, and expensive.

tpm 3y ago

I don't want to see stoves. Like ICEs, they should be left in the past, for healthier and more efficient solutions.

infecto 3y ago
The majority of the underdeveloped world has no way to achieve that in the near term. The healthier more efficient solution is indeed higher efficiency fuel stoves. The great part of that is it can also spur new business with the help of NGOs/Governments/Funds etc. You get local businesses to make high efficiency stoves, subsidize for people who cannot afford, new businesses to make the fuel, thinking of things like charcoal or wood pellets (that one might be a little more complicated but still doable).
- oblio 3y ago
  > The majority of the underdeveloped world has no way to achieve that in the near term. Why, though? Solar panels are becoming very cheap and induction stoves aren't necessarily high tech. Ikea makes this: https://www.ikea.com/us/en/p/tillreda-portable-induction-cooktop-1-zone-black-30546508/ https://www.ikea.com/us/en/p/tillreda-portable-induction-coo... Surely a cheap knock off could be made for $10-15 or something.
  - defrost 3y ago
    The link didn't appear to have the current draw .. but there's a very good chance it's high relative to a single solar panel or two in areas that lack reliable grid electricty. Hence the comment about the majority of the underdeveloped world and the near term. ( A key feature of much of the underdeveloped world is a general lack of IKEA kitchens with handy wall plugs and 24/7 high wattage grids )
    - oblio 3y ago
      > The link didn't appear to have the current draw .. but there's a very good chance it's high relative to a single solar panel or two in areas that lack reliable grid electricty. Product details -> Good to know -> Connection rating: 1800W. That's max power, I imagine they could run it at 900W, which, from what I see, would be 2-3 panels. Also, I don't think it's the "majority of the underdeveloped world". Based on this: https://www.statista.com/statistics/521212/number-of-off-grid-population-asia-africa-by-select-country/ https://www.statista.com/statistics/521212/number-of-off-gri..., to me those numbers look something like 20-30-40% of the population in these underdeveloped countries. Anyway, it's kind of a moot point, this will probably happen on its own over time, where it makes sense. > ( A key feature of much of the underdeveloped world is a general lack of IKEA kitchens with handy wall plugs and 24/7 high wattage grids ) This snark is irrelevant. I didn't say they should buy it from Ikea, ergo my comment about the $10-15 copycat (probably from Aliexpress). Nor did I say they should buy an Ikea <<kitchen>>. You can plug that thing on top of a $2 table to a regular wall plug or even an extension cord.