Step-by-step guide about how we, at Durham Wildlife Trust, with the help of a fantastic team of volunteers, produce charcoal on a large scale. The charcoal is sold to help fund all the conservation work we do in the area. For more information on DWT's work or to volunteer see www.durhamwt.com.
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Step 1: Equipment:
-"par char" wood (partially burned)
-Coveralls, gloves, mask and goggles
- hack saw
Step 2: Preparing the Kiln
The first task is to prepare the kiln for the burn, this requires donning coveralls, masks and goggles and thoroughly cleaning the inside of the kiln and the vents.
Step 3: Placing the First Logs
Once cleaned, the bottom of the kiln is filled with a series of short logs, cut down to around one metre in length. These logs are set out in the shape of spokes, aligning with the vents and forming a central 'fire space'.
Step 4: Filling the Kiln
Further logs are placed around the spokes to form a well ventilated base for the chopped logs to be loaded onto. A rectangular chimney should be built up in the centre, above the 'fire space' and filled with partially burnt wood (par char) obtained, primarily, from previous burns.
Step 5: Topping Up and Putting on the Lid
As the wood is placed into the kiln, it is slightly over filled, leaving a gap of, ideally, around 75cm between the lid and the kiln, which closes as the wood burns down.
Step 6: Lighting the Kiln
The morning after the kiln has been filled three diametrically opposed vents should be opened and fitted with chimneys, at which point the kiln should be lit. The best time for this is around 6am, this gives plenty of time for the burn to take place, usually between eight and 12 hours.
Step 7: After the Burn
At completion of the burn period the vents are closed and the contents allowed to smoulder and eventually die out. This process reduces the content to charcoal. Once it's cold, the kiln can be opened the contents removed.
Step 8: Emptying the Kiln
Following the burn, masks, coveralls and googles should be worn again as the kiln is emptied. Beginning with the partially burnt pieces of wood (par char for the next burn) and the fine dust. After this the charcoal is removed, graded and bagged.