[Terrapreta] Fw: "open-air dirt mound kiln"
Duane Pendergast
still.thinking at computare.org
Wed Oct 3 11:01:21 EDT 2007
Joe
I'm a long way from physics classes, but I do think Sean is confusing the
velocity of individual molecules of hydrogen with the behavior of a hydrogen
gas stream. Here is a link.
http://physics.ucsc.edu/~josh/6A/book/gravity/node12.html
I recall that the kinetic theory of gases indicates hydrogen molecules can
move around in the atmosphere at velocities exceeding escape velocity. That
does not mean that hydrogen from a release of hydrogen gas would be directed
upward at escape velocity. Such a discharge of gas from the postulated kiln
would mix by convection and diffusion into the atmosphere rather quickly.
It would be a shame to waste the energy from those flammable gases that way
though.
Duane
-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of joe ferguson
Sent: October 3, 2007 7:46 AM
To: terrapreta
Subject: Re: [Terrapreta] Fw: "open-air dirt mound kiln"
Sean K. Barry wrote:
----- Original Message -----
From: Sean K. <mailto:sean.barry at juno.com> Barry
To: Robert Klein <mailto:arclein at yahoo.com>
Sent: Tuesday, October 02, 2007 5:11 PM
Subject: Re: [Terrapreta] "open-air dirt mound kiln"
Hi Robert,
You will have to study this more carefully, I think.
As, I see it there are three possibilities with the operation of a "dirt
mound kiln";
1) After and if pyrolysis commences, appropriately limiting the oxygen
intake and "producer gas" with an H2, CO, CO2, N2, and CH4 content close to
what I predicted will vent, unburned, from the kiln to the atmosphere (no
flames). This may leave maybe 25% of the dry biomass weight in charcoal/ash
(~40% by volume). The rest of the matter from the biomass WILL vent to the
atmosphere as "producer gas". Unless it is capture and burned in a flame (a
"flare"), then it will go unchanged into the atmosphere, and very fast!
Free hydrogen gas at atmospheric pressure and temperature has a buoyancy
such that it rises at 17,000 miles per hour from the surface. This is
faster than escape velocity.
Where on earth did you get that number? URL, please?
The emissions gases are "hot".
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