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Title: [GreenYes] Re: Questions about incineration vs. coal
At 11:03 PM 12/15/2007 -0600, Curt McNamara wrote:
>A colleague has been asked to comment on approval of a permit to
>re-start an incinerator. It is located at a refuse transfer station and
>would be fed with yard waste and construction debris (no garbage). The
>question is whether this is preferable to land-filling the construction
>waste since the energy from the incinerator would reduce the load on the
>local coal plant, reducing its emissions.
OK, first, can you tell us anything about the burner proposed to be
restarted? Emissions are often as much a matter of the type of
equipment used as what the fuel is.
Then, is there any hard reason to think the burner would actually be
offsetting local coal generation? Could be, but power plants are
usually despatched (run) in a queue based on variable costs.....so
there is no real reason to *assume* much about how the despatch order
would be impacted by adding something else....
>Comments are welcome, especially those that would allow us to trade-off
>one kind of emissions from the other. Thanks!
>
>My question was, with regard to the "eco" biomass incinerator. We're
>concerned about the proposed permit allowing some amount of toxic
>emissions from the plant, which would be a result of burning
>construction waste as there is not enough true biomass materials to
>provide fuel for its operation. I don't know what a good baseline is
>for toxic emissions. The proposed plant would generate up to 25
>Megawatts.
I think you must be referring to the "Midtown" burner proposed in the
Phillips neighborhood of Minneapolis? Attached are some emissions
projections for this burner from the draft air permit.
A key point is these projected emissions are from so-called "clean
biomass," they are NOT presuming that any C&D waste is burned. There
is a common assumption that wood, if not painted, pressure treated,
etc, is a clean fuel. But this is not so. If C&D waste, "RDF," etc,
were added to the fuel mix, some of the emissions such as arsenic
would increase. But others are already high and might not.
>I realize that this would likely take a load off of the coal fired
>plants in the area, so I'm wondering if, compared to coal, this
>biomass/construction waste combination wouldn't be possibly better for
>air quality, even if not ideal.
Comparing coal emissions to "biomass" emissions is complicated, but
many people think the greatest air pollution health threat is from
"nanoparticles," and these are probably higher for "biomass" than coal.
Some coal plants have scrubbers and some don't. This can make a big
difference....
am
>Of course, there are better solutions, such as wind power, but I'd
>like to determine whether this isn't a "perfect is the enemy of the
>good" type of situations.
>
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> Curt
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