[Terrapreta] volatile matter and char

[Michael Antal]

There is no mystery associated with the chemical composition of volatile
matter (VM).  As discussed in our publications and others, VM is composed of
carboxylic, carboxylic anhydride, lactone, hydroquinone, phenolic,
carbonylic, quinonic, ether, and pyrone functional groups attached to a
carbon backbone.  At elevated temperatures (typically above 400 C) these
groups undergo thermal cleavage and form CO2, CO, H2, H2O and CH4 and (at
low temperatures) other organic compounds.  As Gerrit states below, the VM
content of charcoal is largely a product of the pyrolysis process itself. 

 

If Edward Someus were to take the trouble to read our publications, he would
realize that his remarks below (concerning our work) are nonsense.

 

Merry Christmas to all!   

 

Michael J. Antal, Jr.

Coral Industries Distinguished Professor of Renewable Energy Resources

Hawaii Natural Energy Institute

POST 109, 1680 East-West Rd.

Honolulu, HI 96822

 

phone: 808/956-7267

fax: 808/956-2336

www.hnei.hawaii.edu

  _____  

From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Gerald Van
Koeverden
Sent: Friday, December 21, 2007 2:33 PM
To: Terrapreta Preta
Subject: Re: [Terrapreta] volatile matter and char

 

None of our discussions seem to have got us any closer to what "VM" is....

 

1. To what extent is VM just a concentration of pre-existing organic
compounds in wood? For example, the tree has produced certain chemicals to
protect its trunk from insect/diisease; are these just becoming more
concentrated?

 

2. To what extent is VM new toxic chemicals produced through the heat of
pyrolysis? At what temperature are these produced? If higher temperatures
are their origin, then it might well be that lesser/lower
carbonized/torrified wood (the stage of cell collapse and dehydration), such
as suggested by Nikolaus, might be the healthiest precursor to fertile
'char'. It could be that only the intermediate 'incomplete' carbonizing
stages produce a toxic charcoal.

 

Until we get a better handle on this VM mystery substance - its true nature,
origin and decomposition - we just keep going round in circles.

 

Gerrit

 

 

 

 

 

 

On 21-Dec-07, at 12:54 PM, Edward Someus wrote:






Antal makes more gasification with high burn off, resulting more alkaline
ash. This is not reduce VM much but increases ash significantly, we do not
want.

True carbonization is in absence of any air, process is made in vacuum and
it gas out not gasify.

Sincerely yours: Edward Someus (environmental engineer)
Terra Humana Clean Tech Ltd. (ISO 9001/ISO 14001)

3R Environmental Technologies Ltd. 
ADDRESS: H-1222 Budapest, Szechenyi 59, Hungary
TEL handy: +(36-20) 201 7557
TEL / FAX: +(36-1) 424 0224
TEL SKYPE phone via computer: Edward Someus
3R TERRACARBON: http:// <http://www.terrenum.net%20> www.terrenum.net 

3R CLEANCOAL ENERGY:  <http://www.nvirocleantech.com/>
http://www.nvirocleantech.com

 <http://www.vertustechnologies.com/> 

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

From: Gerald <mailto:vnkvrdn at yahoo.ca>  Van Koeverden

Date: 2007.12.21. 14:02:58

To: Edward <mailto:edward at terrenum.net>  Someus

Subject: Re: [Terrapreta] volatile matter and char

Edward,

 

I understand that VM is not composed of naturally occurring substances, but
that it itself is a product of the carbonizing process. 

 

If this is so, then maybe the main reason for high or low VM charcoal
product depends more on how much oxygen there is in the reactor to convert
the VM or its building blocks into CO2? Thus the more Dr. Antal pressurizes
his carbonizer with air prior to firing it, the less VM he would have in the
charcoal produced in his flash reactor??

Gerrit

 

 

 

On 21-Dec-07, at 1:52 AM, Edward Someus wrote:

 


SEAN

Technical response on VM:

*	RE VM has an insecticidal effect
*	YES, TARS ARE TOXIC FOR LIFE
*	 
*	RE Low VM% is obtained at high temperatures, basically
*	NOT ONLY, NO MATTER IF YOU HAVE HIGH TEMP AND LONG RESIDENCE TIME IF
THE TECHNOLOGY HEAT TRANSFER EFFICIENCY IS LOW. == ORGANICS ARE LOW HEAT
CONDUCTORS.
*	 
*	RE Higher temperatures produce a more "activated" charcoal too
("activated" charcoal has a high adsorption surface area)
*	NO, ACTIVATION IS AN DIFFERENT PROCESS, BY HIGHT TEMP ONLY YOU CAN
NOT REACH HIGH SPECS SURFACE AREA
*	 
*	RE Now, charring biomass on a forest floor or in the soil will not
likely allow such high temperatures (~1000C) to be achieved, so one wonders
how the original Terra Preta soil was made with low temp char and does not
suffer from toxicity. RE Perhaps any toxicity in fresh low temperature
charcoal is lost over time once it is in the soil. 
*	TP IS NOT CHAR ONLY, IT IS A BLEND. YES, TOXICITY IS CHANGING BY
TIME, AND SOONER OR LATER ADAPTED MICROBIOLOGICAL COLONIZATION MIGHT OCCUR.
BUT THIS PROCESS IS HIGHLY DEPENDING ON SOIL TYPE + CLIMATE CONDITIONS AS
WELL. TP ORIGINAL WAS IN TROPICAL CLIMATE WHERE ORGANIC DEGRADATION IS
ALWAYS FAR MORE RAPID THAN IN CONTINENTAL CLIMATE. TP MODEN AGE DOES NOT
HAVE DECADES OF TIME TO WAIT FOR ALL THIS.


Sincerely yours: Edward Someus (environmental engineer)
Terra Humana Clean Tech Ltd. (ISO 9001/ISO 14001)

3R Environmental Technologies Ltd. 
ADDRESS: H-1222 Budapest, Szechenyi 59, Hungary
TEL handy: +(36-20) 201 7557
TEL / FAX: +(36-1) 424 0224
TEL SKYPE phone via computer: Edward Someus
3R TERRACARBON: http:// <http://www.terrenum.net%20> www.terrenum.net 

3R CLEANCOAL ENERGY:  <http://www.nvirocleantech.com/>
http://www.nvirocleantech.com

 <http://www.vertustechnologies.com/> 

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

From: Sean <mailto:sean.barry at juno.com>  K. Barry

Date: 2007.12.21. 5:43:40

To: Terrapreta Preta <mailto:terrapreta at bioenergylists.org> ; Gerald Van
Koeverden <mailto:vnkvrdn at yahoo.ca> 

Subject: Re: [Terrapreta] volatile matter and char

Hi Gerrit,

What is the source/cause of high volatile matter in char? Does this VM
(since it is 'volatile') decrease/volatize by itself over a short time? 

 

According to the article "VM" content is "a measure of the susceptibility of
charcoal to further decompose and form carbon when heated."

 

Translation, please?? 

We've asked Dr. Michael J. Antal this very question, when he was subscribed
to the list. He was vague about what VM actually is then, too. It is
measurable as the percent weight (VM%) of a charcoal sample (this is done
using a "proximate analysis" test), but its chemical analysis is a mystery.
Some others have recently mentioned VM has an insecticidal effect (Dr.
Reddy). Edward Someus also says high VM% content on charcoal is a problem in
soil. People working with Eprida, Danny Day, Dr. Christoph Steiner, etc.,
were wondering if the VM% was a benefit as "food for microbes".

>From what I have read about pyrolysis reactions, the VM% content is be
dictated primarily by maximum internal particle temperature in the char bits
(this can be somewhat related to residence time in the reactor). Low VM% is
obtained at high temperatures, basically. Higher temperatures produce a more
"activated" charcoal too ("activated" charcoal has a high adsorption surface
area). Now, charring biomass on a forest floor or in the soil will not
likely allow such high temperatures (~1000C) to be achieved, so one wonders
how the original Terra Preta soil was made with low temp char and does not
suffer from toxicity. Perhaps any toxicity in fresh low temperature charcoal
is lost over time once it is in the soil.

As you suggest, VM is "volatile", so I imagine it does dissipate somewhat
off the surface of the charcoal, through reduction by oxygen from the air,
or water. This has been recognized as a "storage" problem for fresh
charcoal. Fresh charcoal can spontaneously ignite! THis occurs when the VM
reacts and creates heat). Another question I had was, ... What about
charcoal from natural forest fires that are quenched out by rain, for
instance?. Wouldn't these be low temperature and leave toxins in the soil?
But, as has been observed, soils on which forest fires have run across do
not stop plant growth. In fact, there is a "bloom" of new growth. So, what's
up? (with this "toxicity of of high VM% on low temperature charcoal" scare).

I think this premise needs testing. I think no none who has provided any
"field results of using charcoal in soil" here yet, has known that the
charcoal they used was low VM% or even what temperature the char was made at
(no data on this presented). I can make charcoal with my reactor and control
the max temperature inside the reactor core. I can do a "proximate analysis"
test on any charcoal produced and make measurements of VM%. I cannot
discover any ways yet to characterize the chemical analysis of the VM in any
way. Dr. Antal got short with me when I asked him about doing this. He told
me, like in the paper, Volatile Matter is only quantifiable, not
characterize-able. (Who gets to say, "That's bunk!" to a PhD?).

It may be that the processes required to produce low VM% charcoal are more
expensive than otherwise, so these producers are trying to play up the value
of their product. I think the premise needs testing. I think most testing
occurring now is NOT seeing this detriment in their plant growth results.

Carry on.

Regards,

SKB

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

From: Gerald Van Koeverden <mailto:vnkvrdn at yahoo.ca> 

To: Terrapreta Preta <mailto:terrapreta at bioenergylists.org> 

Sent: Thursday, December 20, 2007 7:53 PM

Subject: [Terrapreta] volatile matter and char

 

G.

 

The article is at the following link:

 

http://www.ctahr.hawaii.edu/DeenikJ/Downloads/Tai_Charcoal_CTAHR_Sym_2007.pd
f

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