[Terrapreta] a braoder theory of torrefaction and TP
Gerald Van Koeverden
vnkvrdn at yahoo.ca
Mon Dec 10 11:29:54 CST 2007
Nikolaus,
Loved your photos!
I like your idea....we 'soils peoples' have to broaden our scope of
interest from 'biochar' to the whole range of "torrefied wood". Let
me try to build a new 'theory."
Torrefaction does something to the wood so that it lasts much longer
in the soil than non-torrefied wood. What happens in torrefaction?
"This process removes all naturally occurring resins, sugars and
oxygens while collapsing the cells. This accomplishes two things:
First, it gives the lumber a deep, rich brown color...Second, and
more importantly, it alters the wood to make it extremely stable,
moisture resistant and decay resistant."
This extended life effect is not just because it drives out enough
moisture to inhibit decomposing organisms, but it also provides a
suitable habitat for non-decomposing soil-dwelling organisms - not
dependant on as high moisture contents - which in turn protect their
habitat from rapid decomposition. If these MO don't completely
inhibit decomposition, they at least have a significant effect in
slowing that process down. It is the biological activity of these
micro-organisms inhabiting the torrefied wood, which increases the
fertility of those soils and make TP's what they are.
There are different degrees of torrefied wood, ranging from very dry
wood to charcoal. Perhaps charcoal is merely the extreme type that
lasts the longest in soil?
It's interesting to note, that soil scientists attempting to
decompose wood complain about how hard it is to do so...whereas, like
for char, if the above theory is correct, we should be complaining
about how fast it happens...
Gerald
On 9-Dec-07, at 10:29 AM, Nikolaus Foidl wrote:
>
> Dear Gerrit¨
>
> The photos show Torrefied wood pieces some still house nematodes
> and Termites as well some very fine roots. ( brown to dark brown
> material which is brittle but stronger then charcoal) The texture
> on the surface is still intact and not eaten up after 15 years
> buried in the soil, they are humid, speculating with more then 50%
> humidity. The smaller black junks are charcoal chunks with a quite
> good quality ( metallic shine where you brake them)
> And then you have everything in between wood , partially charred,
> partially torrefied etc. So I personly think that even the Indians
> some 2000 years ago did not employ a high-tech temp. Controlled
> charring process with predried wood and controlled charring
> environment, they produced as well some thing which had the same
> range of wood to partially torrefied and partially charred and
> partially burned. That's it. Now maybe the mixture of all that
> allowed the formation of what we call terra preta today and not the
> high tech approach we are discussing today.
>
> Regards Nikolaus
>
>
> On 12/8/07 8:50 PM, "Gerald Van Koeverden" <vnkvrdn at yahoo.ca> wrote:
>
>> Nikolaus,
>>
>> I very much look forward to seeing your photos.
>>
>> The scientists seem to be arguing that torrefied wood ('grey
>> charcoal') preserves so well precisely because of its
>> hydrophobicity; by keeping water/moisture out of the wood, fungi
>> can't grow inside it. But maybe they need to take a second look
>> to find the real reason that torrefied wood lasts so long?
>>
>> Fungi and other microorganisms don't destroy black charcoal
>> despite them being able to colonize it; heat has changed the
>> chemical characteristics of the wood into a material very
>> resistant to chemical breakdown; if your observations on
>> torrefied wood particles are correct, we might discover that the
>> same is true for 'grey' charcoal, that the real reason for the
>> preserving qualities of torrefaction have nothing to with the
>> wood's initial hydrophobicity but rather particular chemical
>> changes in its structure...??
>>
>> Or maybe the real reason for both black and grey charcoal's long
>> life is something else again...we know that as trees grow older,
>> they secrete certain chemicals into the wood of their trunk which
>> function as preservatives and pesticides to protect the tree as a
>> whole. Maybe our multiplicity of microorganisms are doing the
>> same tfor our charcoals - manufacturing and secreting
>> preservatives to maintain their habit...why not?...it's a radical
>> idea, I grant you...but after reading about some of the many
>> intricately wondrous strategies developed by plant life to survive
>> and thrive, it wouldn't surprise me at all...
>>
>> We could be on to a whole new hypothesis.....
>>
>> Gerrit
>>
>> On 8-Dec-07, at 6:16 PM, Nikolaus Foidl wrote:
>>
>>> Dear Gerrit!
>>>
>>> The material is wet like the charcoal chunks next to it . That
>>> it is not eaten up by fungi does not mean it cant house fungi and
>>> bacteria. Hydrophobicity is cureable ( very cheaply) and the same
>>> they say about charcoal. I will take some Fotos ( close ups) so
>>> you can appreciate the stuff. But the important thing is still i
>>> burry more not degradeable CO2.
>>> Best regards Nikolaus
>>>
>>>
>>> On 12/8/07 6:20 PM, "Gerald Van Koeverden" <vnkvrdn at yahoo.ca>
>>> wrote:
>>>
>>>
>>>> Nick,
>>>>
>>>> I had to look up what torrefaction was:
>>>>
>>>> "Torrefaction is mild pre-treatment of any biomass (including
>>>> bamboo) at a temperature between
>>>> 200 and 250° C. During torrefaction the properties of bamboo
>>>> undergo changes, wherein the end
>>>> product has much better fuel quality compared to biomass for
>>>> combustion application. The
>>>> decomposition reactions during this process results in bamboo
>>>> becoming completely dry and
>>>> loose its tenacious structure, also the hygroscopic nature of
>>>> the biomass is changed to
>>>> hydrophobic material. Besides this, the process increases the
>>>> calorific value of the end product.
>>>> The actual weight loss in this period would be about 20 to 25 %
>>>> whereas 90 % of the energy of
>>>> the parent dry material is preserved in the torrefied matter.
>>>> The combustion process of this matter
>>>> has less problematic volatiles and hence the process is closer
>>>> to that of charcoal. It can therefore
>>>> be used as an alternate to charcoal in many applications. It
>>>> also makes the material immune to
>>>> attack by fungi. Hence long term storage without degradation is
>>>> possible."
>>>>
>>>> Based on 15 minutes of research, it doesn't look promising. It
>>>> would seem that this super-drying of wood makes it
>>>> hydrophobic...and if it stays that dry in the soil, it would be
>>>> difficult for nutrients to move through a soil solution into
>>>> it. Moreover, it doesn't sound like it is conducive for a
>>>> 'fungal' bridge between itself as a microhabit for microrganisms
>>>> with the soil; in char mixed with composting material, the char
>>>> actually becomes a microhabit for fungus...
>>>> However, this is only speculation.
>>>>
>>>> How closely have you examined the torrefied wood you have found
>>>> in the soil? Does it 'house' microrganisms? Has it absorbed
>>>> soil nutrients? Or is it merely an inert material taking up space?
>>>>
>>>> gerrit
>>>>
>>>>
>>>>
>>>> On 8-Dec-07, at 2:21 PM, Nikolaus Foidl wrote:
>>>>
>>>>
>>>>> Dear all!
>>>>>
>>>>> My charcoal costs at a charring efficiency of 42 % is around
>>>>> 35 US$ per ton
>>>>> Charcoal. Now after analyzing 15 year old soil where huge
>>>>> amounts of forest
>>>>> where simply burned and charred. Now excavating I find huge
>>>>> amounts of only
>>>>> torrefied wood pieces which as well did not degrade, like the
>>>>> charcoal
>>>>> chunks.
>>>>> Now looking at this and if torrefied wood would do the same as
>>>>> is charcoal,
>>>>> why not save a huge amount of additional CO2 and just torrefy
>>>>> the stuff and
>>>>> mill it and then burry it? Cost per ton would drop to half,
>>>>> CO2 taken out of
>>>>> the atmosphere rise by 50 to 70 %.
>>>>> Just an idea but maybe worth to be discussed.
>>>>> Best regards Nikolaus
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
> <image.jpg><image.jpg><image.jpg><DSC00710.jpg><DSC00711.jpg><DSC00683
> .jpg><DSC00686.jpg>
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