TLUD Update – updated

I had an epiphany while running a comparison between a couple of TLUDS at Simon Days about 10 days ago. I’ve been trying to get more char out of my system by raising the afterburner about 50mm above the main barrel so I can feed in extra wood through the secondary air inlet after the burn stabilises.

While the secondary feedstock has been charring well, the main charge has been producing too much torrified and untouched chip. I suddenly realise that, by raising the afterburner I was destroying the draft created by it and the flue because the extra gap meant that the flue was not drawing any air through the bottom of the barrel, the secondary air inlet was the path of least resistance.

I reverted to the original configuration, with the afterburner sitting firmly on the top of the barrel and the previous good performance of the system returned with less than 15% brands.

Then, greedy for more product, I tried removing the afterburner during the burn and adding a small pile of branches up to 50mm in diameter. At first I thought I had broken the system with huge amounts of mostly white smoke billowing out and no chance that the afterburner would relight to combust the smoke. However, I realised that the fire front, about half way down the barrel, was proceeding as normal, the draw from the flue was still working at that level.

Next option was to remove the afterburner again and add some dried cryptomeria foliage, my favourite fire starter in all cases. I quickly had the smoke burning again and the temperature of the afterburner rose to a self-sustaining level and the burn proceeded as normal.

The extra wood charred very well, all the way through, with very little smell and a nice crisp snap on breaking. Final composition was fully charred with no more than 15% brands and possibly less.


  • The original design appears to confer the strongest draw through the main feedstock charge and I have abandoned the wider secondary air gap.
  • Opening the system to add an arbitrary amount of extra material for charring seems feasible
  • It will depend on reigniting the smoke with more tinder before replacing the afterburner.

Next time I will try to double the extra fuel and/or add in some road kill to add calcium char as well.

Next Time

Another run today, (February 14) adding about 10 litres of various sized branches around 30cm long and between 10mm and 30mm diameter.

Once again we had trouble reigniting the afterburner, the moderate breeze that sprang up during the burn didn’t help, blowing out several matches while the barrel smoked liked fury. once I got a bunch of cryptomeria actually burning I still had to hold the afterburner partially open for a couple of minutes to keep the flame burning really hot and bring the afterburner up to temperature to ignite the pyrolised gases.

After that it settled quickly and burned normally till the end with about 10% unburned material as usual. The results of the extra feedstock were spectacular. All of the extra wood was almost perfectly charred, snapped cleanly and had very little to no smell. All of it looked like this

30mm branch added to TLUD after the burn had established at about one third of the way through the burn.

30mm branch added to TLUD after the burn had established at about one third of the way through the burn.

Next time I will just take off the flue and add the extra wood through the top of the afterburner. We wont be able to control the distribution on the top of the chips but I’m not expecting that to make any great difference; the space is very hot and anoxic, as this material demonstrates perfectly.

2014 Biochar Companies & Organizations

I’m not sure that this link will work for you all… it is an extensive listing of biochar companies on the Biochar Farms & Gardens Linkedin group. You may need to be in the group to access.

2014 Biochar Companies & Organizations Alphabetically Listed by Thermal Conversion Technology Type, Organizations by Services

Biochar Systems Consultant Top Contributor

Please send me New Companies for Addition & Failed Companies for Deletion;”

Climate change, geoengineering, biochar – the NZ link

Biochar is a veritable Swiss army knife for some of the planets problems. There are many tools being unfolded for agriculture enhancement and environmental repair. Energy tools abound, due to the diverse range of biochar production methods, and their residual and distributed nature. Continuing the analogy, one of the largest and most controversial knifes is still to be sharpened.

Some biochar proponents are pushing hard for biochar as a carbon sequestration tool. It is suggested to be a passive and safer approach to geoengineering the planet compared with other CDR (carbon dioxide reduction) or SRM (solar radiation management) methods that have emerged from the geoengineering community.

Kelpie Wilson has posted on a two year NZ and UK study looking at public attitudes to geoengineering. Her link leads back to the Manawatu Standard 13Jan news report but she says nice things about sensible kiwis so do check out her blog…

I’ve been engaged with this issue from another perspective – the NZ ETS… my comments are included in Euan Mason’s blog post below…

Biochar producers page

We have been getting inquiries for biochar – mainly from gardeners wanting to experiment. As interest grows, demand for larger quantities should follow for commercial application trials. If you are producing biochar in NZ and you are able to share some of your production with gardeners or researchers, then please get in touch.

As the market for biochar matures, we should develop some principles and guidelines for sustainable and safe biochar production, post-treatment and application. The easiest path for now may be to follow IBI, European or other international production / testing guidelines.

We are developing a list of NZ biochar producers who may be able to provide biochar or biochar based products from direct inquires. The producers page will provide contact details and product information.

Biochar Burn School

Kelpie Wilson from has led this initiative…

“A quick summary of results of experiments in open burn techniques to minimize smoke and maximize charcoal production. Experiments were conducted by volunteers over a 3 day period, November 15-17, 2013, outside of Grants Pass, Oregon.”

Biochar burn school 1Biochar burn school 2

WRC Technical Support Group RFP

An opportunity here for to get biochar understanding into an expert panel.  This Waikato river quality program should be well funded and should include support for biochar nutrient management research. My June posts are probably connected with this new initiative…

Do let me know if you want a copy of the documents.

GETS Reference: 41024
Title New Zealand based opportunityExpression of Interest for a Technical Support Group: Healthy Rivers: Plan for Change/Wai Ora: He Rautaki Whakapaipai Project
Expression of Interest
Your Reference Number
General Information The Waikato Regional Council invites expressions of interest for membership of a Technical Support Group, for the Healthy Rivers/Wai Ora project. The Technical Support Group will be part of a Technical Alliance which will provide expert advice and information to the Project. The Technical Support Group will be a panel of specialists available to the Project for the purposes of research, data collation, report writing and peer review, as guided by a technical leaders group.
Respond by Date
Address Enquiries to
All communications relating to this EOI must be directed to the Council Contact Person as follows:
Vicki Carruthers
Technical Workstream Leader and Senior Policy Advisor
Phone: 07 8590536
Or Jenni Sommerville, phone: 07 8590939, if Contact Person unavailable

Use of biochar for the sustainable remediation of sheep dip sites

The following presentation was given by Sam Gregory at the 2013 WasteMINZ conference on 23 October 2013:

“Application of biochar to a soil contaminated with organochlorines and arsenic (As) from a past agricultural practice known as sheep dipping was analysed to investigate its effects on contaminant mobility and plant growth characteristics during a 180d glasshouse and field trial study. Soil from a known dip site was removed and treated with biochar made from a willow (Salix sp.) feedstock (pyrolysed at 350°C and 550°C) added at 20 t ha-1 and 40 t ha-1 to gauge the appropriate treatments to be used in a later field trial. Soil microbial activity as analysed using the dehydrogenase activity assay (DHA) was significantly increased (P<0.01) under all biochar amendments. After 60 d of amendment, biochar containing soils underwent > 100% increase in DHA resulting in significant decreases in alpha-HCH (10-fold) and gamma-HCH (3-fold) concentrations in soil. Significant reductions in DDT with biochar amendment were also noticed after 180 d of treatment compared to unamended soils. Biochar did not increase water-extractable arsenic concentrations but significantly (P<0.05) increased phytoextraction into both a arsenic hyperaccumulator fern (Pteris cretica) and ryegrass (Lolium perenne). Ryegrass growth was signifcantly increased (P<0.01) under biochar amendment with 2-fold increase in shoot dry weight and 3-fold increase in root dry weight after 180 d. These results have the potential to reduce the remediation time of contaminated soil and decrease the environmental risk to nearby ecosystems.”

Author: Samuel Gregory, Dr Chris Anderson, Assoc. Prof. Marta Camps-Arbestain, Prof. Michael McManus, Massey University

Attachments: WasteMINZ 2013 Use of biochar for the sustainable remediation of sheep dip sites