[Terrapreta] Electrical conductivity of charcoal + 08 wishes

geoff moxham teraniageoff at gmail.com
Fri Jan 11 21:16:35 CST 2008

Hi Sean,
I am interested in quick tests for suitability for biochar.
Hence the conductivity trials. I might as well to PAs as well,and
check for correlations.
I will certainly be doing proximate analysis and probably ultimate
analysis on the hemp hurds through Dr Bolton and SCU, and if I can get
him to do the same for some samples of red cedar and bambusa I will
try. Then I can calibrate my home trials?

I only have a paint mixers scale which I will do some home PA with,
especially for the interesting species for us, like lantana and
crofton weed and the species I cant find on the CSIRO P Analysis
database, like cedar and bamboo. The CSIRO site is extensive, and
represents heaps of work already done, and it also has gasification
tests on many samples.

I like the recent microporosity data posted here, from which I will
draw my kiln design process constaints. (Anyone have any electron
micrography of microporosity?).

 I have just spent a year researching parabolic solar thermal home
power systems using heat stored through superheated steam tubes into a
hot rock filled kiln.
Due to NNSW rain and cloud I have completely abandoned those plans.
How fortunate... given the current fooding! However I have a 1cu m
kiln to play with...I want to go for a ridiculous efficiency in kiln
heat losses, so I can do day long **soaks** to use a pottery term. I
intend to skin the ex HT porcelain kiln with another layer or two of
fire brick and even maybe wood after that.(hate styro)

Perhaps the electrical conductivity is related to the formation of
graphite sheets/tubes/buckyballs?

I am convinced limelight is a winner and accessible. Please post any
links you have to it. Currently making a **hard mantle** from V low
density HT kiln brick. checking materials suitability is easy with a
small blowtoch or the oxy.
I run on a burnt shoestring  and eat weeds.
Geoff Moxham

On 11/01/2008, Sean K. Barry <sean.barry at juno.com> wrote:
> Hi Geoff,
> Are you doing "proximate analysis" tests of the charcoal produced in your
> "biscuit tin" pyrolysis experiments?
> #6 Experiment with Limelight (1850 to1910) driven by woodgas mini
> generators.
> That's an interesting experiment.  Wood gas and coal gas were both initially
> used to fir gas lights, circa 1850-1910.  Both these gases are forms of
> "synthesis gas" or "producer gas"; mostly in declining relative amounts, N2
> (in "producer gas"), CO, H2, CO2, H2O, CH4, O2, and trace others, etc.
> Depending on how the source fuel of was oxidized during pyrolysis, the
> consistency and amount of the gases would vary.
> Regards,
>   ----- Original Message -----
>   From: geoff moxham<mailto:teraniageoff at gmail.com>
>   To: Terrapreta at bioenergylists.org<mailto:Terrapreta at bioenergylists.org>
>   Sent: Thursday, January 10, 2008 10:03 PM
>   Subject: [Terrapreta] Electrical conductivity of charcoal + 08 wishes
>   Hi list,
>   I have been charring in 44 gal drums for  a while now, to supply the
>   garden, the orchard and the Midge stoves that keep evolving. So I have
>   a need for both agricultural and cooking charcoal.
>   I use mainly forest red gum, but a few drums have been mixed  rainforest
> spp.
>   plus whats lying around including bamboo (bambusa), lantana, and scrap
> meranti.
>   Playing with the midge one day I was measuring the current drain of
>   the computer fan motor (50mA!) and calculating how long it would run
>   on a car battery continuously (about 1.5y?) when der... carbon
>   conducts...lets look at that  biscuit tin full of mixed rainforest
>   charcoal...
>   3 hours later I was on the net finding a bamboo charcoal pillow
>   maufacturer with his prods stuck in his pillow showing 0 Ohms....just
>   what I found....the site said good charcoal conducts...yet the blue
>   gum has very high resistance (megohm range), and blue gum bark off the
>   scale resistance. All of the lantana conducts, all of the bambusa,
>   some of the others...all from the same batch....aaak!
>   I then searched this site for electrical conductivity of charcoal and
>   found nothing.
>   Anybody out there gone there?
>   I am now designing a series of closed (the hundredth monkey biscuit
>   tin) pyrolysis tests on each species including toona australis and
>   camphor spp. for conductivity tests.
>   And that will have to be x3, using kiln temps of 400, 600 and 800 C.
>   in the space heater...great visual access and fume cupboard for the
>   experimenter.
>   seeya
>   geoff
>   PS
>    wishlist for 2008
>   #1 finish 1 cu.metre AlOx kiln with durablanket, and fire large loads
>   with long **soaks**, optimising for microporosity.
>   #2 Do another Garnaut Review submission or 2 (Thanks folks)
>   #3 Carbon date some local midden charcoal ...anyone help there?
>   #4 Pyrolise Dr Keith Boltons hurds, after separating from the bast in
>   this years agricultural hemp trials through SCU.
>   #5 Experiment with gunpowder
>   #6 Experiment with Limelight (1850 to1910) driven by woodgas mini
> generators.
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