Adelaide Hills Biochar Initiative

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by Brian Lewis - September 23rd, 2016

REPORT OF WORKING BEE carried out on 17 June 2016 at Blewitt Springs, South Australia.

Gareth Carrel: Vigneron
Greg Marlu: Biochar producer
Matt Quinn: Compost producer
Brian Lewis: Biochar blogger

To build 3 biochar production kilns based on Greg Marlu’s adaptation of a top lit updraft gasifier kiln.
This kiln is a simplified version of the Anderson TLUD design in that it does not have an outer drum or top aperture to provide heated secondary air. Greg has found that provided the wood chips are dried before use this design is adequate for making good commercial- quality biochar.

A clear flat area about 8m x 8m with no flammable material or overhanging trees.
A water supply.
A supply of dry wood chips.

Wool or cotton outer clothes.
Eye protection.
Long fire-proof gloves.

MATERIALS USED (for 3 kilns):
3 x 1 ½ 44 gallon drums, galvanised steel.
3 x 300mm dia. galvanised steel ducting, 1800 mm long.
3 x set of 3 standard house bricks.

Electric drill with 15mm drill bit.
Cutting oil (RP7)
Angle grinder
Pitchfork (for wood chip handling)
Propane gas lighter
Mirror on stick (to view underneath main drum)

1. TO MAKE MAIN SECTION using one drum:
1.1 Drill 40 holes with 15mm bit in bottom of drum, evenly spaced. Start with 8 mm drill bit.
1.2 Remove top of drum with angle grinder.

2. TO MAKE BURN CHAMBER with adjustable air vent using half a drum:
2.1 Remove a 150 mm high section from open end of half-drum with angle grinder.
2.2 Flare edge of remaining open end of drum so that it fits over the open top of the main drum.
2.3 Cut 3 flaps in edge equi-distant around circumference about 50 mm wide and 20 mm high so
that the resulting flap can be bent inwards to help secure chamber onto top of main drum.
2.4 Take the 150 mm drum section and cut it through at one point so that an open hoop remains.
2.5 Bend back the two ends about 50 mm to form two flanges.
2.6 Drill a matching hole in each flange to suit available piece of fencing wire to hold flanges
2.7 Mark out 6 cut-outs evenly around the hoop, each cut-out to be 100mm wide x 50 mm high.
Tip: Radius of drum is about 1/6 of its circumference.
2.8 Cut out each cut-out with angle grinder.
2.9 Cut a flap out of top side of hoop about ¼ circumference from hoop opening to form a crude
2.10 Make matching cut-outs in the half drum.
2.11 Fit hoop to the half drum and check alignment of cut-outs.
2.12 Place pipe section on top of half drum in centre and mark a circle around pipe.
2.13 Mark lines from circumference of circle to centre of circle at equal intervals to make 10
2.14 Drill hole in centre of circle.
2.15 Cut along each line from centre to circumference.
2.16 Bend up each section at right angles to top of half drum.
2.17 Check that pipe section fits securely on top of half drum.

3.1 Locate main drum on 3 bricks to provide air access to holes in bottom of drum.
3.2 Locate half drum with fitted hoop onto top of main drum. This is the burn chamber with adjustable vent.
Note: Adjust the vent holes to about half open for normal operation. Vent only needs to be fully opened during final stage of the process if the char begins to ignite. Increasing the vent opening reduces draft to reduce air flow to any burning char.
3.3 Fill main drum and burn chamber to top of vent holes with dry wood chips.
3.4 Fit flue pipe to top of burn chamber.
3.5 Open vent fully.
3.6 Use propane lighter to light wood chips accessible through each vent hole.
3.7 Once well alight reduce vent opening to about half-way.
3.8 Observe operation and take precautions to prevent the possibility of accidental contact with hot surfaces (eg. Barrier; Warning signs, etc).
Note: Some smoke will issue from flue during start-up phase while the top layer of wood chips burns. This takes 5- 10 minutes. Then flue emissions should be smoke-free and remain that way until completion.
3.9 Observe discolouration of the external surface of main drum and note area of high temperature.
Note: This high temperature region takes up about 1/3 of the height of the drum and moves slowly down the drum as the woodchips are progressively converted to biochar.
3.10 When the high temperature region reaches the bottom of the drum check for burning char using the “mirror on stick”. If char is burning a red glow will show through the air holes. If there is a red glow open the vent fully to reduce air draft or alternatively block air flow completely. The flame colour is also an indication of char temperature; the flame colour changes towards the blue end of the colour spectrum as it gets hotter (eg. red, orange, yellow, blue).
3.11 Get water supply ready to dowse the char.
3.12 Remove the flue pipe.
3.13 Remove the burn chamber. Check that volatiles have finished burning.
3.14 Tip the main drum over to allow the char to fall out onto a sheet of iron or similar fire proof surface.
3.15 Apply a water spray and thoroughly dowse until all the char is cool to touch.

4.1 The construction is simple and suitable for most DIY people.
4.2 Not suitable for use in suburban gardens or anywhere where a fire permit is required.
4.3 Operation is simple and is essentially hands-off once started except at completion OR if smoke
emissions occur.
4.4 If wood chips used are too damp the process stalls, smoke emissions occur and the drum needs
to be emptied and contents quenched.
4.5 Wood chips need to be spread and dried before use.

Many thanks to Gareth for providing the site for this working bee and to Greg for sharing his knowledge of kiln-making with us.


















by Brian Lewis - September 23rd, 2016

The South Australian WEEKENDER HERALD NEWS recently printed an article entitled “SUBSTANCE COMBATS GLOBAL WARMING” featuring a photo of “yours truly” holding some biochar. This excellent article crafted by journalist Lucy Robinson kindly referred to my 5 years of biochar trials while managing local equipment manufacturer Flow Force Technologies; and recommended my new book “Making Biochar – with Technical Manual” for anyone wanting to take up the practice of producing biochar.

The article also referred to my suggestion that local councils get on board and allow landholders the option of using a biochar kiln to convert their tree litter to biochar instead of burning it. The recent extensive storm damage in the Adelaide Hills coupled with new State government legislation banning the burning of garden waste in townships has aggravated the problem of tree litter disposal prior to onset of the bush fire season.

You can read the article on page 2 of the 1 Sept. 2016 issue or use the following link:

and go to page 2.


by Brian Lewis - September 6th, 2016

Hi out there! Sorry to have been away from the blog for so long. I have been busy developing two new types of biochar kiln. A brief summary follows:

One is a gasifier kiln based on the principles of the “Troika” TLUD (Top Lit Up Draft) gasifier stove developed by Dr. Paul Anderson. I have called this our Series 2 Style.

The other is a retort style kiln that allows the syngas to be used as a fuel for the kiln or diverted to a gas scrubber (i.e. gas cleaner) prior to burning or storing. This is similar in concept to the “Hornito” system developed by Robert Lerner of Biochar Costa Rica. I have called this our Series 3 style kiln.

The Series 3 kiln has been extensively tested and used by Temple Bruer Winery at Milang as part of their on-going program to become carbon neutral in their own right.

After I had done all that I retired so do not have any further commercial interest in making or selling biochar kilns.

However I would still very much like to encourage more people to make biochar.

So with that in mind I have written and published an e-book entitled “Making Biochar – with Technical Manual”. This has been published by Strong and Bold Publishing (my new publishing business) and is available for $9.99 from Please take a look at it. And if you like it please let me know. Or even tell me how it could be improved. The book is possibly unique in that it includes complete fabrication drawings for the Series 2 and Series 3 style kilns referred to above.


by Brian Lewis - July 26th, 2012

I know there are a few people actually developing and trialling various types of carboniser here in South Australia. But they don’t get much coverage in the media these days. If you are either building, developing, trialling or buying either a batch or continuous carboniser feel free to send your details here with a bit of a story and tell us about it. Don’t hide your light under a bushel!


by Brian Lewis - May 14th, 2012



The author of The Biochar Revolution, Dr. Paul Taylor recently contacted me to discuss the Flow Force Technologies biochar kiln that we have been testing in the Adelaide Hills. He is interested in possibly using it in his community garden projects in northern NSW.

He is currently using an Adam retort but believes there may be scope for a number of different styles of kiln depending on the type of feedstock, the type of user and the ultimate purpose of the biochar.

I believe the Flow Force biochar kiln is well-suited to community garden use. It is mobile and simple to use. It is relatively fast in operation (typically 4 hours per batch compared to 24 hours for some other systems). It is easy to load and unload by virtue of the revolving loading/unloading hatch.  It provides an electronic record of kiln temperature so the maximum temperature and duration of pyrolysis can be confirmed for each batch. It uses a built-in solar panel to operate the electronics so does not require an external supply of electricity.  


Chapter 1 of Paul Taylor’s book is available for free download at or from the website And the foreword by Dr. Tim Flannery is well worth reading and inspiring in itself.


by Brian Lewis - November 10th, 2011


The International Biochar Initiative (IBI) recently released for public comment its draft guidelines for specifications of biochar. The guidelines cover terms and definitions; feedstock requirements; safety requirements; testing; product labelling etc.

My initial comments on the guidelines are as follows:

Definition of biochar: The definition is over simplified, viz: “A solid material obtained from the carbonisation of biomass”. I think that any word preceded by the term “bio” suggests that it is of biological origin. Well charcoal made from coal is of biological origin (from fossilised plant matter).

So why the term biochar? I presume that it has been coined to try to discriminate between char from non-fossil sources and char made from fossil sources. The claim that biochar has the potential to be carbon negative by acting to sequester fixed carbon in the soil is relevant to the definition.

If we are going to have a biochar methodology for approving carbon credits then it goes without saying that the process of making biochar must be carbon negative as the calculation of carbon credits would have to be based on the mass of fixed carbon actually sequestered in the biochar less any carbon actually generated and added to the atmosphere as carbon dioxide by the production process.

So I believe that we need to expand the definition of biochar to mean that it only refers to char produced in such a way that it avoids more carbon dioxide than it generates. For example:

“Biochar is a solid material obtained by the carbonisation of biomass in a carbon negative process.”

Then it would be good to qualify the term with further definitions that specify the efficiency of its carbon dioxide avoidance.

If we let % CO2 Avoidance = (CO2 avoided-CO2 generated)/CO2

avoided x 100% then the following definition of biochar could apply :

BiocharNNN would be biochar produced with a carbon avoidance efficiency of NNN%. Eg: Biochar100; Biochar80; etc.

I guess I am concerned at the possibility in the future of large industrial processes for making and selling so-called biochar where the biochar has little or no carbon sequestration value. To me that would be a gross misuse of the term biochar as I think it was originally envisaged.

The document may be viewed at

It is open for public comment until 15 Nov. 2011.

Send comments to:


by Brian Lewis - October 28th, 2011

Refer attachment to view results of biochar analysis:

Analysing Biochar _Wet & Dry_


by Brian Lewis - October 28th, 2011

The demonstration batch carboniser was re-located
in July to a site near Echunga in the Adelaide Hills.

We can now demonstrate biochar production
in a rural setting. To arrange a demonstration
simply make an appointment by email.

We will now accept organic woody waste for conversion
to biochar at no cost. One 200 litre green bag of dry
material per person will be converted free of charge
with additional batches priced at $0.50 per kg of
biochar produced.

To make an appointment or to arrange dropping
off your green bag send an email to:

The photo above shows the demonstration unit
at the new site.


by Brian Lewis - August 4th, 2011

BIOCHAR PRODUCTION CENTRES in the Adelaide Hills and Country Regions will provide the following benefits:

Future Vision – Biochar Production Centres_


by Brian Lewis - June 6th, 2011

Test Results Summary