Sent: Sunday, April 21, 2002 7:32
AM
Subject: Re: GAS-L: Transportation Cost
and Storage
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
