[Terrapreta] Indigenous burning

[Tom Miles]

Neal,

 

As you can see from the website it is direct combustion. Burning biomass
with coal is called co-firing or (in Europe) co-combustion. If we co-fired
15% biomass with coal in our cola fired plants we would meet the obligations
the US would have if we signed the Kyoto agreement. So the project is
justified by reducing the amount of coal burned. Since the biomass is more
expensive than the coal it must be paid for by using the incentives we
provide for reducing greenhouse gases (CO2, Sox) and sequestering carbon.

 

In Oregon we harvest and process more than 600,000 tons per year of straw
from our grass seed harvest. The cost of that straw harvested, stored and
delivered to an industrial process is between $35-$45/ton. You get about 1
MWe from a ton of biomass when it is fired alone (combustion or
gasification) or about 1.4 MWe per ton when it is co-fired. At 1 MW/ton then
biomass at $10/ton make electricity with a fuel cost of $0.01/kWh; $40/ton =
$0.04/kWh. Energy crops like switchgrass must also carry the cost of
establishment and cultivation so add another $10-$15/ton to the cost. If
straw at the plant costs $50/ton and it costs $20/ton to process  then the
total cost of $70/ton ($0/07/kWh) is well above the cost of
coal(about$0.01/kWh), or power from coal ($0.04/kWh) anywhere. So the gap
must be made up by mandated renewable standards, state and federal
incentives including carbon credits. 

 

Further the ash from firing biomass with coal must be accepted by the cement
and concrete users who are currently buying the flyash from the coal plant.

 

You are right; biomass is a costly and challenging fuel.  

 

Tom         

 

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From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of CAVM at aol.com
Sent: Sunday, February 18, 2007 10:57 AM
To: terrapreta at bioenergylists.org
Subject: Re: [Terrapreta] Indigenous burning

 

In a message dated 2/18/2007 11:15:33 A.M. Central Standard Time,
tmiles at trmiles.com writes:

In Iowa we have been burning switchgrass, a native prairie grass, as fuel in
an industrial boiler. http://www.iowaswitchgrass.com/ Our experience in Iowa
has shown that a native prairie grass like switchgrass will have about 4-6
tons of removable straw per acre and another 1.5 to 2 tons in the form of
stubble for a total of 6-8 tons per acre

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Tom, is this direct combustion or gasification? How do the economics work
out for paying the farmers for the switchgrass?  We have conducted a couple
of studies of the economics for various groups and farm raised biomass ends
up pretty expensive.

 

Neal Van Milligen

Kentucky Enrichment Inc

www.kentuckyenrichment.com

cavm at aol.com

 

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