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James and fellow list members,
I have been a Lurker on this list for many months and this is my first
post and I take this opportunity of saying hello to all. Rather than repeating
myself here, I have recently made my first post to the "Stoves" list under
the subject "another lurker pops up" and you can get some insight to my
activities by referring to that post.
James Fields wrote:
"I am examining the feasibility of
constructing an indirect fluidized bed gasifier and utilizing the gas for
energy production. I am looking for suggestions or rules of thumb
on estimating transportation costs of the wood feedstock"
I am presently in the process
of setting up a woodchip to power operation but on a much smaller scale,
I am setting up the entire operation at the site where we grow and harvest
the fuel from coppiced woodland. You haven't said just what the wood chip
is coming from but if it is wet I presume it is tree debris rather than
scrap lumber (which could be rain soaked/waterlogged in any event), either
way, do you really want to pay to transport hundreds of tons of water 15
miles across Texas? If you can't set up the plant at the site of the fuel
source, which is by far the method of choice, then the next best thing
is to leave what you don't want at that site and what you definitely don't
want is water! - water will be your biggest problem throughout the entire
operation it gives you transportation problems (every 20 ton load can include
around 8 tons of water), storage problems (fungus and spores etc) and a
greater chance of spontaneous combustion problems and final combustion
problems by, amongst other things, diluting the gas. Tom Reed made a very
valid comment in his reply to my post on "stoves" he said (quote) " We
don't burn wet gasoline, so why should we think we can burn wet wood?"
However the combustion problem can be overcome by employing the combustion
method that I use, but I haven't got to worry about transportation costs,
if I did then I would certainly dry before transporting.
Sun drying woodchip is slow and
not easy, which is why woodchip makes such a good horticultural mulch,
the mechanical handing requirements for constant turning of the chip during
sun/free air drying may be economically prohibitive, especially with the
quantity you are consuming and the time scale allowed. I would suggest
that you set up a drying operation at the landfill site using a recirculating
steam drying process, moving the wood chip through in a thin layer on a
conveyor or even by bulk drying it before chipping, it will pay for itself
in no time and can of course be fired by woodchip or, if available, methane
from the land fill. This method will also provide "waste" heat which can
be reused on the site, you may even be able to sell it back to the landfill
site for heating etc. By using this method you can transport ONLY the dry
fuel using bulk containers which will give you at least 35/40 percent more
combustible fuel capacity per trip. Storage problems on the power site
can also be overcome by using a "just in time" method and holding only
a few days supply.
I hope this will be of help.
David Reynolds-Lacey
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