October 2013

We are trying to (a) reduce the amount of emmisisons from charcoal production and (b) Condense and recover as much of the smoke into a usable product for your home/farm. Wood tar - the following is an explanation from the good folks at Food and Agriculture Organization of the United Nations (FAO) about what is going on in this process.
"The non-water component consists of wood tars, both water soluble and insoluble, acetic acid, methanol, acetone and other complex chemicals in small amounts. If left to stand, the proligneous acid separates into two layers comprising the water insoluble tar and a watery layer containing the remaining chemicals. Recovery of the water insoluble tar, often called wood or Stockholm tar, is simple - it is merely decanted from the water phase. This wood tar has uses as a veterinary antiseptic, a preservative for wood, a caulking agent, and as a substitute for road tar" http://www.fao.org/docrep/x5328e/x5328e0d.htm

For more pictures click here

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Notes from Ed:

Hi sorry I havn't been following all of this thread, but I thought this might be of interest to somebody,

I am a market gardener, I produce a steady stream of biochar from my water heating systems. I live in Wales, it is cold and wet here and I like washing in hot water.

I have played with bringing tlud stoves indoors but it is not easy and so I have built water heating systems using what I call biochar rocket stoves (sorry if this brings back bad memories Crispin!)
Because they are not filled, lit and emptied from the top they can easily be left in place under heat exchangers, hot plates and a flue outlet pipe. Here in Wales this is important.
If you run them in the evening, when you most need space heat and cooking, then after a couple of hours you have your biochar. It is fine to keep them burning for as long as you want (whereas there is a limit to how much you can keep topping up a tlud)
Unlike wood burning stoves, it is possible to have the flue outlet angled up about 30 degrees from horizontal and surrounded in a thermal mass to capture residual heat. Otherwise the 8th photo is of a section of flue outlet with integral thermal mass.
Shut a door on the front and the biochar goes out overnight. My CO meter has yet to read 1ppm indoors. Empty the biochar by sliding out the floor of the stove and it drops straight into a metal bucket, no quenching, no dust and no mess.
The first photos are of these stoves connected to a 50 litre water tank + hotplate and oven for cooking. (The pipe in the second picture is to give secondary air to the flames.) The system in these photos is mobile and connected to a small header tank so that I can do demos at permaculture conventions and workshops.
The youtube video link below is of something different; a double walled flue pipe with feed and empty hoppers for putting in biomass and emptying out biochar. A bit like an anila stove except the inner combustion pipe has no floor, it goes straight through to the stove below. If its ok with Crispin, I was thinking of calling this flue pipe an anila flue pipe.

http://youtu.be/MTiSTrdYuoA

Lighting Cone on the Keren Stove no smoke 1 min after lighting
Anglo Supra Nova Stove
Loading the Anglo Supra Nova Stove
Good Fit for Cone Lighting
Lighting Cone on the Anglo Supra Nova
Handles get hot on lighting cones - make them large

Lighting Cones can help make traditional and charcoal stoves light more efficiently and with less smoke than other lighting methods. For the best detail, download the Masters thesis pdf from Kathleen Lask

From Crispin Pemberton-Pigott's Description:

"The main principle is that there should be enough draft to light the fire rapidly. The lighting cone provides this if it is about 500mm tall."

"The second principle is that the bottom of the cone should sort of cover the lighting fuels so that most air is pulled from below, not from the side."

"The third principle is that if there is a secondary air supply at of just below the top of the fuel, the bottom of the cone should bypass it so that the heat inside the cone is not used to pull air through the secondary air ports. Very few stoves have a secondary air controller."

In the result with good fit: "You can just see on the left that it bypasses the secondary and draws all air from below, through the fuel – in this case charcoal. Peter Coughlin reports it reduces the charcoal ignition time by more than ½. We will quantify the smoke reduction and GERES way independently confirm it at some point – it is about 90%."

Lighting stoves can also be used with traditional fires. In tests lighting damp wood in Suba Island "The speed of ignition and reduction in smoke was dramatic. You can just see the hot air distortion of the picture above the cone – basically no smoke. It is quite a bit cleaner than the fire when lit and the cone removed."
The cone on the 3 stone fire is 125

The Stove in the top example is an Anglo Supra Nova.
"It was developed at YDD during the World Bank/Indonesian Clean Stove Initiative."

"It as an Anglo Supra with preheated secondary air. It can burn wood or charcoal, and it can burn wood pellets in TLUD mode. It can automatically switch from pellet burning TLUD pyrolyser mode to char-burning mode by using a disc of paper on top of the grate."

"The loose piece of clay is a door which can close the primary air without affect the secondary air. It provides a significant level of power control without adding or removing fuel. The heat transfer efficiency burning charcoal (it is nominally a charcoal stove) is about 50%. It Is portable with handles and sells retail for about $5.50."

Kathleen’s investigation is attached.

Regards
Crispin

Joshua B. Guinto in the Phillippines used the Oblak Holey Roket stove as inspiration and created a stove with an extra compartment to store char until cooking is done and the char is sufficiently cooled. He has done a wonderful job of writing up the results in the attached pdf.
From his conclusion:
The Charmaking Stove is Born!

  • The Char Making Holey Roket Stove is born!!
  • It allows harvesting bio char safely and conveniently and without having to tip the stove over. It eliminates the risk of heat fatigue, burns and open fires.
  • It allows clean cooking with the similar performance as a gasifier stove.
  • It allows continuous cooking.
  • The stove will last for four years or more.
  • It can be used with many other kinds of fuels.
  • The stove is much cheaper and can be fabricated in village workshops thus promotes social inclusion much better.
  • With clay, the stove has very small ecological footprint.

Air Force 1 Sage Low

Marc Pare has a been keeping notes on his attempts to solve the problems of burning rice hulls in household cooking stoves in his rice husk design log: http://ricehusk.cc/goodboiler/

In it, he goes back to the beginning of 'stove'-ness and introduces design and prototyping concepts as well as giving his test results.

Check it out. Shop Sneakers in Footwear