Re: Biochar on the floor of forests Air Curtain Burners?? #technology #aircurtainburner

Tom Miles

I remember the work that Dr. Makato Ogawa did with putting biochar in rows between acacia (?) trees.


From a practical point of view making biochar from forest residues to solve water quality and stream flow issues with vegetative strips and filters probably has more cost savings and practicality. As one forester says, if you have water quality issues in a stream just look upslope at the forest cover.


It turns out that we need to justify making biochar on more than savings to make it through the various administrative structures in our state and national forest organizations. : -)




From: <> On Behalf Of Stephen Joseph
Sent: Saturday, November 14, 2020 12:13 PM
Subject: Re: [Biochar] Biochar on the floor of forests Air Curtain Burners??


Hi Tom


It would be very interesting to see what the reduction in cost of fire fighting is by having a layer of refractory biochar on the soil that builds up soil moisture and whether this biochar also reduces pest infestation


Australian aboriginies use to lay down a row of biochar on the forest floor between trees.  No-one knows for sure why they did this but my guess is the above effects.





On Sun, Nov 15, 2020 at 2:31 AM Tom Miles <tmiles@...> wrote:



What concerns do you have about emissions? We did third party field testing according to our emissions permit. Our permit took months to obtain while our state environmental quality folks did their own evaluations. Oregon is known for its stringent emissions regulations. They were given an extensive library of third party emissions testing to review. Testing has been done on full scale units using methods which are more accurate than testing in a shed.


The emissions are impressive, especially when compared with open burning. I have been designing and testing combustion devices from mobile burners of similar scale to large scale power plants for more than 45 years. Any system can be abused but Airburners has done a good job of supplying a system that burns cleanly when operated properly.


If you assume that emissions are acceptable then you have the cost of the operation and the yield, value, and use of the char.  Who pays for the incremental cost of carbonization?  On public land, as Gordon and others have pointed out, it is not always clear how funds can be made available for carbonization. Can you justify the cost for production of 8-10 tons of biochar from 100 green tons of forest residues in a day?




From: <> On Behalf Of Suze Collett
Sent: Saturday, November 14, 2020 1:38 AM
Subject: Re: [Biochar] Air Curtain Burners??


Thanks Tom, I'd not seen Rick's reply.

Meanwhile, I found the Air-Burner tech reports here ...

The 2007 Lit Review on emissions highlights some inadequacies in data & prompts some ideas.  Granted - tests were not conducted during optimized operation to produce char for Biochar.  Emissions data in this paper is rough though ...

Tests inside a very large shed would be nice - to assess emissions from some vegetation samples.

Cody - on organic matter - the Forestry mob has to avoid transferring insect-infested or diseased vegetation to uncontaminated areas.  Portable units to char veg/trees onsite will eliminate insect &/or disease transfer.



On Sat, 14 Nov 2020 at 00:24, Tom Miles <tmiles@...> wrote:

As Rick mentioned the air burners are promising. Like most systems there are three components: the fuel, design of the device and operation of the device. The air curtain burners can be operated as incinerators or to maximize char extraction Emissions are good and proven. They can be operated to keep most of the fuel in a pool of pyrolysis gases. We expect the maximum char recovery to be similar to gasifiers when operated to optimize char. Both the systems commercially available and the USFS version are still  in development to optimize char recovery.




From: <> On Behalf Of Rick Wilson via
Sent: Thursday, November 12, 2020 11:46 AM
Subject: Re: [Biochar] Air Curtain Burners??


Hi Cody,  Actually, I think this approach could be the breakthrough the biochar world needs. Super low cost. Smaller sizes. Airburners has permitted one of these in California below Title V. 

Its going to take some development because these systems are designed to incinerate. To produce biochar you need to keep the embers in an anaerobic state, which in principle an air curtain could do, just like a flame-cap kiln. Airburners has a cooporative R&D agreement with the US Forest service to figure out how to operate it in biochar mode.  




On Nov 12, 2020, at 11:25 AM, Cody Harrison <codyharrison08@...> wrote:


What do people think of air curtain burners? They're going to be incredibly inefficient in terms of biochar production correct? These seem to me to be the exact opposite direction we want to go, putting probably 95% of the carbon in the atmosphere, completely wasting all that precious organic material that could go into the soil, but want to see if there are any other perspectives? I suppose they might make sense in areas that have a TON of biomass, but I'm down in San Diego and in arid landscapes where organic material is so precious this seems like insanity to me, what do y'all think?



Cody Harrison
Beyond Sustainability Specialist, Corona Enterprises

434-242-6879 | | Portfolio


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