<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">Art,<br>
Have you got any data on char cation exchange capacity?<br>
Alex<br>
<br>
<br>
<br>
On 17/06/2013 2:23 PM, Art Donnelly wrote:<br>
</div>
<blockquote
cite="mid:CALyHvqo37-Z7aOL65tdTnUgdzXzSXHoDcS92DKC0EGywLnyToA@mail.gmail.com"
type="cite">
<meta http-equiv="Context-Type" content="text/html;
charset=ISO-8859-1">
<div dir="ltr">
<div>
<div>
<div>
<div>
<div>Hi all,<br>
</div>
I want to provide some information on the ability of ND
TLUDs to utilize coconut waste as an input material as
well as comment on the relationship between the temp. at
which char is produced and the issues of yield and
surface area.<br>
<br>
</div>
Coconut shell and coir burn very well and very cleanly in
the ND Estufa Finca TLUD.<br>
</div>
Obviously the dense shell is preferred for it's longer
burning time, but the mix gives us a great biochar, which
the nursery men seem to like. Perhaps this works well in
this stove because we use more secondary air than I see in
some other similar stoves? As with other fuels, we can
continue to add this material to the stove as it burns, to
extend cooking time. This strategy does result in a lower
yield of char, than the straight load and burn to completion
method. <br>
When we load the stove, light it and run it until the flame
color changes we routinely yield 30-33% of the the original
dry weight of the input material as biochar.<br>
<br>
</div>
I monitor both our Estufa Finca stoves and 55-gallon drum J-RO
kilns with a K-type digital probe thermometer. The stoves
pyrolysis front produces char between 500-700c the J-RO
between 600-800c. I have had Hugh McLaughlin characterize
approx. 14 samples of different material made in these and
material processed in retorts with a temperature not exceeding
450c. The biochar from the TLUD type devices all have greater
available surface area than the same materials produced at the
lower temperature range. Wood, bamboo and coconut shell all
come in around 400m2/g. Close to the low end for activated
charcoal. These chars are giving us good results in the soil
when mixed with compost or inoculated with EM. The reduction
in tars in the higher temp. chars is a plus.<br>
<br>
</div>
<div><br>
</div>
Art.<br>
<div><br>
</div>
</div>
</blockquote>
<br>
</body>
</html>