[Terrapreta] Strong warning against "simple" charcoal kilns

Sean K. Barry sean.barry at juno.com
Mon Apr 28 08:19:02 CDT 2008

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Hi Max,

I'd say that I would be surprised too, if Methane escaped that. I don't know this for sure, but I do not think burning CO or H2 (or both) will produce that kind of temperature (1500C). I thought Methane would burn at 1200C (But I could be wrong)? I don't know if the temperature inside a piston of an internal combustion engine even reaches 1500C. This is very hot. How do did you measure this 1500C temperature?

The mechanism which will tell you if ALL of the fuel gases are being burned is called a "lambda sensor" or an oxygen sensor. If it measures NO OXYGEN left in the exhaust gases, which can be at most 19% oxygen (NO BURNING), then there is still un-burned fuel gases in the fuel gas/air stream. If there is any oxygen left (>0%), then there are no unburned full gases left. Lambda sensors on the exhaust port are what are used to throttle the air/fuel mixture with modern internal combustion engines.

I think that the "holes" around the bottom of the outer barrel, which let in air, cannot "throttle" the air/fuel mixture. By this, I mean if the fuel gas production goes up, then they do not introduce more air and vice versa. I suppose it might be possible to maintain the temperature somehow, which would might maintain a specific air/fuel mixture, but still what temperature would you choose to guarantee complete combustion of the exiting "producer gas"? Unless the production of gas is just right, then the holes will not allow enough oxygen to burn the entire fuel charge that is exiting between the rim of the inner barrel and the bottom of the outer barrel.

Regards,

SKB
----- Original Message -----
From: MFH<mailto:mfh01 at bigpond.net.au>
To: 'Sean K. Barry'<mailto:sean.barry at juno.com> ; 'Kurt Treutlein'<mailto:rukurt at westnet.com.au>
Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
Sent: Monday, April 28, 2008 3:06 AM
Subject: RE: [Terrapreta] Strong warning against "simple" charcoal kilns

I can't speak for Volke's system, but in the trials with my experimental drum kiln the temp of the gas flame under the drum reaches 1500C+ in the presence of free O2.

I'd be surprised if any methane escapes that.

Max H

------------------------------------------------------------------------------

From: Sean K. Barry [mailto:sean.barry at juno.com]
Sent: Monday, 28 April 2008 2:43 PM
To: 'Kurt Treutlein'; MFH
Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
Subject: Re: [Terrapreta] Strong warning against "simple" charcoal kilns

Hi Max,

Not necessarily. Methane-CH4 burns at a higher temperature than CO or H2. Burning the (CO and H2) gases will use up the available oxygen before the Methane-CH4 will burn. There is almost 10 times as much CO and ten times as much H2 in "producer gas" as there is Methane-CH4 in producer gas. The heat of formation of Methane-CH4 (the energy needed to begin combustion) and the amount of oxygen needed to burn Methane-CH4 are both greater than either H2 or CO. So, the H2 and CO content in the "producer gas" start burning at lower temperatures and will use up most, if not all, of the oxygen before the Methane-CH4 can even begin to burn. To burn the Methane-CH4 would require injection of oxygen above what is needed to combust the CO and H2. The heat generated from H2 and CO burning may ignite the Methane-CH4, but without enough oxygen, it will more likely just just eject it from the reactor, un-burned, because there was not enough oxygen left.

Regards,

SKB

----- Original Message -----

From: MFH<mailto:mfh01 at bigpond.net.au>

To: 'Sean K. Barry'<mailto:sean.barry at juno.com> ; 'Kurt Treutlein'<mailto:rukurt at westnet.com.au>

Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>

Sent: Sunday, April 27, 2008 10:36 PM

Subject: RE: [Terrapreta] Strong warning against "simple" charcoal kilns

Sean

Sorry if I'm being a little thick about this, but if the methane has to pass through the fire zone at the base of the inner drum, won't it burn?

----------------------------------------------------------------------------

From: Sean K. Barry [mailto:sean.barry at juno.com]
Sent: Monday, 28 April 2008 10:24 AM
To: 'Kurt Treutlein'; MFH
Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
Subject: Re: [Terrapreta] Strong warning against "simple" charcoal kilns

Hi Max,

Try this? When carbonacious organic wastes (biomass?) are left to decay in open air, they decompose into CO2. When pushed underground into a landfill, some of the carbon molecules in the biomass decompose into Methane-CH4, which is also under the ground, and is often already being harvested. In fact it is illegal to allow Methane-CH4 emissions from landsfills. It can be economical to harvest the trapped Methane gas found in landfills. There is quickly growing industry in harvesting ""landfill" gas. Fecal wastes from animal feed lots is also are left mostly, to decay in open air, producing both CO2 and CH4. Anearobic Digester systems can harvest the Methane from animal waste pools.

Now, the "charcoal-in-a-barrel" kiln? Well, when biomass if pyrolyzed in open air (or limited amounts of air). This pyrolysis reaction generates "producer gas" (H2:~20~, CO:~20%, CO2:~10-15%, H2O:~5%, Methane-CH4:~2-3%, and Nitrogen gas-N2:~40-45%)

Air is 19% Oxygen, 78% Nitrogen, Argon is next, and some other trace gases (like CO2 @ 383 parts per million).

The release of just the 2-3% Methane-CH4 content does more damage to the atmosphere than is ALL of the carbon were released as CO2. This is because Methane-CH4 is a long-lived and far more potent contributor to the green house warming effect than is CO2 (23-62 times more potent, depending on how long of a time frame you consider). The production of large amounts of charcoal using "charcoal-in-a-barrel' kilns (and the release of any substantial portion of the Methane-CH4 from the process would undermine Terra Preta Nova in a profound way. Here we would be trying to mitigate climate and improve growing conditions, but while we tried we shot ourselves in the foot and advanced the speed of increase in the GHG warming effect.

This doesn't even mention other pollutants possible from charcoal production in cheap simple "charcoal-in-a-barrel" kilns. These include particulates (carciniogens) and other toxic , air borne compounds. Who ever "sits" sucking in smoke form a camp fire? It also does not mention that there is an enormous waste of usable energy, due to the inefficiencies of this type of design.

See http://en.wikipedia.org/wiki/Methane<http://en.wikipedia.org/wiki/Methane>

There are some who will dispute this claim. I know that there are more who would support this. If you must learn about charcoal in soil, then make some charcoal by any means, if you cannot get it from someone who can make it right, but advocating "millions" of these typoes of kilns is a bad idea. Advocate "millions" of "Clean Charcoal Kilns" instead.

Regards,

SKB

----- Original Message -----

From: MFH<mailto:mfh01 at bigpond.net.au>

To: 'Kurt Treutlein'<mailto:rukurt at westnet.com.au>

Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>

Sent: Sunday, April 27, 2008 6:28 PM

Subject: Re: [Terrapreta] Strong warning against "simple" charcoal kilns

I'm struggling to understand why "millions" of back-yard simple kilns
producing char to be buried in gardens aren't better than not having any at
all. More particularly if they are consuming household scraps and garbage
that would otherwise find its way to landfill.

Sit on our hands and wait for big business to develop squillion dollar char
factories, or do something positive at a personal level?

Max H

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org<mailto:terrapreta-bounces at bioenergylists.org>
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Kurt Treutlein
Sent: Monday, 28 April 2008 9:21 AM
Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
Subject: Re: [Terrapreta] Strong warning against "simple" charcoal kilns

Hi folkes,

Hands up all those who have "Strongly warned" against Folkes simple kiln
concept, who are NOT working on developing a sophisticated highly
efficient pyrolises system with the idea of marketing it to the world to
make the gigatons of bio-char we will need to reverse GW.

Anybody???

Kurt

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