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I also believe that Tom's original question was
related to combustion, not anaerobic digestion (which eliminates the various
dairies and swine facilities around the country [e.g., Minnesota, California,
New York, North Carolina] that are generating electricity from biogas produced
by anaerobic digestion of the manure).
A few comments on this topic:
1. The nature of broiler/turkey litter is
substantially different from cow/steer manure. Litter is the combination
of bird manure plus bedding material, which is generated (and ultimately
removed) after the birds have been grown on the bedding (the number of
flocks of birds per batch of litter depends on numerous factors: the
location of production facility [practices vary around the country], type of
bedding material, producer/integrator management practices, etc). Bedding
material typically consists of wood shavings, sawdust, rice hulls, or straw
(other organic residues/materials are also used, but in relatively small
quantities).
Litter can be a reasonable biomass fuel because
of:
a) the high degree of cellulose in the bedding
material (some/much/most of which is still in the litter when it is removed,
depending on the bedding/litter mgt practices noted above);
b) the relatively low moisture content (typically
25~30%); and
c) feasible logistics (litter is relatively easy to
collect, transport, grind, and feed into a furnace system)
In contrast, cow/steer manure is relatively wet,
does not contain nearly as much cellulose, and may be difficult to
collect.
Thus, litter is more attractive as a fuel for
combustion/gasification than cow/steer manure.
2. However:
a) Both materials have high ash content (litter is
typically around 20%).
b) Both materials are widely recognized as great
soil amendment materials but as lousy fuels, relative to other biomass
feedstocks. (I happen to share that perspective, but recognize that in
certain situations, combustion/gasification is a better option that land
application or processing into other soil amendment products [e.g.,
compost].)
3. FibroWatt has 3 electricity-generating
power plants in the U.K. that are 100% fueled by chicken litter; they are
currently negotiating to build a similar facility in Minnesota (using turkey
litter) and have been pursuing similar opportunities in other areas of the U.S.
where there is concentrated poultry production.
4. In my opinion, potential
combustion/gasification of steer/cow manure in this country will be limited to
arid areas where there are large feedlots, e.g., west Texas, because: a)
large quantities of material at a single source (feedlots in the western region
commonly have 30,000 ~ 40,000 head within a 2-square mile facility (@ about 75
lbs/day of manure @85% moisture); and b) the material scaped up in the corrals
has low moisture content (as low as 30%) due to climatic
conditions.
An exception might be a situation where there is
access to [affordable] dry biomass for bulking up high-moisture
manure.
Having said all that, I also would be greatly
interested to learn of ANY facilities worldwide that are combusting/gasifiing
steer/cow manure (and the nature of those feedstocks and the local electricity
markets).
Jim Wimberly
Foundation for Organic Resources
Management
----- Original Message -----
Sent: Tuesday, July 24, 2001 12:57
PM
Subject: RE: Steer/Cow Manure Burning
Biomass Plants
It should
be clarified that Dennis Haubenschild's farm converts cow manure to methane in
a digester, and the methane is then burned in a Cat engine, which then drives
an electrical generator. The system works great mainly because Dennis is an
outstanding operator.
I assumed
that Tom Miles comments referred to the direct combustion of manure. I do not
know of any successful operations which directly burn manure, but if there
are, then I also would like to know about them.
I
understand that the Fibrowatt Company has boiler designs that allow the direct
combustion of Turkey manure. Does anyone know whether the chemical composition
of Cow manure and Turkey manure is similar enough to allow the direct
combustion of Cow manure in a Fibrowatt combustor (assuming the cow manure
moisture could be reduced to a value which is similar to turkey
litter)
Don
Hello All --
Here's a maunre one that the Minnesota group
has been supporting. Haubenschild Farms
at
----- Original Message -----
Sent: Monday, July 23, 2001 3:20 PM
Subject: Steer/Cow Manure Burning Biomass
Plants
> Major projects to burn
steer or cow manure have largely failed in the past
> because of
excessive corrosion and wear from salt (sodium and chlorine) and
>
high ash content. The last major plant that I know of in the US was in El
> Centro, California. A Herreschoffe furnace was combined with a
fluidized
> bed combustor. Extensive wear and corrosion ultimately
led to closing the
> plant, which is in the process of being
converted to natural gas.
>
> Are there any plants generating
electricity from cow/steer manure anywhere
> in the world?
>
> Tom Miles
> Thomas R Miles tmiles@trmiles.com
> T R Miles, TCI Tel
503-292-0107
> 1470 SW Woodward Way Fax 503-292-2919
> Portland,
OR 97225 USA
>
>
> -
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Archives:
> http://www.crest.org/discussion/bioenergy/current/
>
> Bioenergy List Moderator:
> Tom Miles,
tmiles@trmiles.com
>
> Sponsor
the Bioenergy List: http://www.crest.org/discuss3.html
>
-
> Other Bioenergy Events and Information:
> http://www.fsec.ucf.edu/bioam/
>
http://solstice.crest.org/renewables/biomass-info/
> http://solstice.crest.org/renewables/biomass-info/carbon.shtml
>
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