Cooking fuel is an integral part of daily life around the world. However, it poses some significant challenges in developing countries, including high cost, deforestation, and indoor air pollution. BeLocal wanted to provide a healthier and sustainable alternative fuel source so along with the help of others they were able to demonstrated a process for producing Biomass Briquettes from agricultural waste which directly addresses the challenges of cooking fuel around the world.
Materials for the Charcoal Converter:
200 liter drum
sheet metal (minimum ~0.4m x ~0.4m)
Materials for the Briquette Maker:
sleeve or small piece of sheet metal
rod, wooden log, or bamboo piece (~5-6 cm diameter)
Materials for making the Charcoal:
Dry waste material (e.g. leaves, sticks, rice stalk, banana leaves)
Long rod or sick about 1.5 m tall and (~5-7 cm diameter)
Materials for making the Briquettes:
Binder material (recommended: cassava root, cow manure)
Step 1: Figure Out Side a and B
First, cleanse the inside of the barrel as best as possible to avoid any exposure to possibly toxic substances.
Usually, there are two distinct sides of the barrel: side A and side B. Side A usually contains two holes whereas side B is does not contain any.
Step 2: Cut Sheet Metal Then the Barrel
Cut a piece of sheet metal to fit flat within the ridges of the top of side B. The piece of metal should cover a majority of side B but should it should be easy to place and remove.
Place the piece of sheet metal to the side and proceed to cut a large square into the barrel that is smaller than the size of the sheet metal into the top of side B. The piece of sheet metal should be able to rest on top of the hole you just cut.
Step 3: Cut Into Side A
Cut 5 evenly spaced small holes about 6-7 cm in size on side A.
Step 4: Constructing the Briquette Maker
Wrap a sleeve around a tube, metal rod or sturdy piece of bamboo and secure this shape by using string. The rod should fit snugly into the tube but be easily removed and inserted repeatedly.
Step 5: Making Charcoal
(1) Allow organic waste material to dry in the sun until it is dry to the touch (may take 1 day+).
(2) Dig a shallow pit just a bit larger than the diameter of the barrel. This pit will be used to contain fire and must be safely away from any flammable materials. The depth of the pit need not exceed 15 cm.
(3) Locate three fire resistant bricks, or three rocks of similar size. Arrange the bricks around the edge of the pit so that the barrel can be supported standing on its end without touching the ground.
(4) Tip the barrel on its side and stuff all of the holes on the bottom with wads of dry waste material. These will be used as fuses to carry fire into the barrel and should be packed tight enough to stay in place, but loose enough to burn easily.
(5) Place the barrel upright (with side B facing up) on the bricks. Place the long rod along the central axis of the barrel.
(6) Leaving the pole in place, stuff the barrel full of dry waste. Packing the waste too tight will require excessive cooling times. Too loose will not produce the maximum amount of char per burn cycle. Experimentation with the waste at hand is required.
(7) Remove the central pole.
(8) Tip the barrel on its side and light all of the fuses on the bottom of the barrel.
(9) Tip the barrel upright on the bricks so that the fuses can continue to burn without being extinguished by contact with the soil.
(10) Smoke will be observed coming up from the chimney hole. This smoke will initially be gray indicating that water is being driven out of the waste.
(11) The smoke will eventually turn transparent and occasional flames will be observed from the top of the barrel. Wait until the flames become continuous and start a timer.
(12) After approximately 3 minutes (experimentation is required to match this time to your waste),using heat-resistant gloves, carefully place the sheet metal cover over the top of the barrel and remove the bricks supporting the barrel. This can be done by tipping the barrel a little and kicking the bricks out one by one.
(13) Working quickly, cover the top of the barrel with soil to help prevent air leaks. Also heap soil around the sides of the barrel to prevent air from reaching the bottom of the barrel.
(14) The hot materials inside the barrel will begin turning to charcoal in the absence of oxygen.
(15) Wait until the barrel and all of the material inside the barrel is cool. This should take about two hours. If the barrel is opened too soon, the hot materials with my ignite in contact with air.
Step 6: Making Briquettes
To create charcoal briquette mash, two major components are required: charcoal and binder. Binder can be a variety of substances, however cassava and cow manure has been found to be the easiest to work with and is usually readily available.
(1A) Peel, core, and chunk cassava roots and place them in boiling water until they can easily be mashed into a paste. Once soft, mash the chunks of cassava in pot of water. The starch released from mashing the cassava forms a thick paste with the water. Try to avoid any chunks in the paste as this could severely reduce the quality of our briquettes.
(1B) Acquire dry cow manure.
(2) To make the briquette mash, charcoal was mixed in a 1:1 weight ratio of binder to charcoal.
(3) Mix the mash and slowly add water until brittle balls can be formed by hand. Ensure the mash is well mixed.
(4) Press mash into briquettes using the briquette maker.
(5) Allow briquettes to dry for several days in the sun.