Making Charcoal

Vithusa Biochar Kiln

Vuthisa Technologies in South Africa have been working on improving the Portable Metal Kiln Charcoal Making Method and using a retort design to reduce emissions and improve efficiency making charcoal.

They have a great description with lots of detail on their web site:
as well as a Google Group:!forum/portable-kiln

In short the system is composted of an outer drum, often fabricated of sheet steel enclosing an inner set of 30 gallon drums.


Vuthisa, November, 2009

They have kindly put together a great How to Make charcoal in your own backyard

I recently did some trials with 2 x 55 gal drums inside my fabricated Portable Metal Kiln. I recently increased the kiln width from 1.1 to 1.4 metre diam to accept 3 x 55 gal drums and although more testing is required I am satisfied with the MO. I have created a Google Group to discuss issues around its construction and usage.
Cost: Under $800
Availability: DIY


Updated September, 2012:


R. Diermair November, 2009

Attached as a Power Point file and a PDF is a nicely illustrated guide to creating a TLUD (top lit up-draft) biochar retort with two barrels. As he notes, understanding the TLUD is critical to getting reliable, clean take a look at our other TLUD References for more guidance.

Running sports | Air Jordan Release Dates 2021 , Chnpu

MAKING BIOCHAR: with Peter Hirst of New England Biochar

Many thanks to George Packard of Parrot Creek Productions, Warner, New Hampshire for some really fine work. This is the short version of greater works in progress. Very well done by George and much appreciated.

Peter Hirst

Biochar Trial Photos
Empty Planting Trays on Rack Fine Wet Processed Charcoal Settling in Flask Bamboo Feedstock Softwood Chip Feedstock
Empty Planting Trays on Rack Fine Wet Processed Charcoal Settling in Flask Bamboo Feedstock

I was surprised that there were no how to's for charcoal productions without the need for kilns, drums etc, so thought this might be of interest to some as a trial technique. It is not very efficient by way of volume of charcoal to volume of biomass to start, but can be useful if you have quantities of garden waste such as prunings, bark, leaves etc. This type of stuff normally goes into green waste, or needs chipping to compost or use as mulch as it is too big for compost bin.

This is a process I have used which requires only an open fire or fire pit, shovel or rake and water (hose or steel buckets with water). It is a minor modification of the techniques used when cooking using the camp oven - which only uses coals instead of flame. Instead of transferring the coals to the oven pit, they are wetted down to stop burning, and create charcoal.


Simple charcoal kiln
Folke Gunther, April 24, 2008

A wonderfully simple method for making charcoal at home or on the allotment.



There is a wide demand for charcoal kilns to be used by anybody having an allotment or garden sized plot. The idea of making char of surplus biomass instead of firing it is widely spread in Latin America (and Japan?). Burning the pyrolysis gasses instead of emitting them makes the method comparatively safe, although not efficient regarding their potential utilisation of gasses.

I agree that his is a very small scale method, bu imagine 2 billion people having it, making 1 kg char a week for their lots. That would imply about 0.1 Gt annually, or 5% of what would be necessary to sequester for making a change.

Naturally, this is not the method to save the world from entering a tipping point, but it could well be of some help.

How to Make Charcoal
Robert Flanagan, SAFFE, January 30, 2008

I've just been playing around with my natural draft stove to see how easy it would be to use it for cooking and making charcoal .
I fed some extra fuel in the side so show the pyrolysis reaction taking place.


he author, Gary Gilmore, explains how he designed a charcoal retort from steel drums. This is a smoke free design also the flare could be put to use.

Charcoal by Gary Gilmore video 1

First make the retort by adding air holes to the bottom of a steel drum.
Then make the afterburner by turning another steel drum into a tube.

Then start loading the wood (no more than 20% moisture) tightly packed into the retort. (This contains a great description of wood as nature's battery).

Charcoal by Gary Gilmore video 2

Once you have the wood packed in the retort, build a small fire on the top. (There is a nice description of a top lit retort system). Once the small top fire has caught, ad the afterburner (the tube) to the top of the retort.


Charcoal From Smallwood
in "Niche Marketing Strategies for Products from Small-Diameter Timber
A.L. (Tom) Hammett, Professor, Phil Radtke, and Robert L. Smith, Professor and Extension Specialist, Department of Wood Science & Forest Products, Virginia Tech, Blacksburg, VA, Smallwood 2006
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