Re: burning tires in Syracuse

["Alex J. Sagady & Associates" <ajs@sagady.com>]

At 05:12 PM 12/14/1999 -0500, you wrote:
>In Syracuse NY USA the county-run incinerator is trying to get a permit to
>add shredded tires (to be mixed in with the garbage). Comparative stack
>tests Ogden-Martin provided the state environmental agency showed dioxin
>levels considerably higher with the tires than without (.104 ng/dscm @ 7%
>o2 without tires and .274 ng/dscm with the tires). I am planning to attend
>the public hearing on this request next week and would like to have some
>understanding of the chemistry of this increase. Can anyone help me with
>this? How and why does the inclusion of tires in the fuel increase the
>release of dioxin/furans? Thank you for your help.


If the incinerator runs with chronically poor combustion conditions,
then the addition of tires adds a considerable amount of materials
that will yeild benzene aromatics which are a feedstock for
chlorination and subsequent PCDD/PCDF formation.

However, if combustion is good, the sulfur present in tires may cause
reductions in PCDD/PCDF.

My guess is that this incinerator is operating with poor combustion
conditions and less than the best emissions control.   This will
result in higher PCDD/PCDF emissions.    You'll want to check the
level of carbon monoxide and HC that were detected during the stack
test as clues as to the combustion conditions, although you cannot
be sure that these will necessarily correlate with PCDD/PCDF emissions.
The other parameter to check is the temperature of the flue gas at the
entrance to the particulate matter control device.   If it is inside the 400
to 700 degree window for optimum dioxin formation, then high
PCDD/PCDF emissions can be expected.   It is possible that the
increased heat release that occurred with tire burning caused the
tire burning condition for flue gas temperature to increase to a
more optimum PCDD/PCDF formation temperature window.

If you like, I can forward a copy of an EPA monograph on how
PCDD/PCDF forms in these combustion systems.


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Alex J. Sagady & Associates        Email:  ajs@sagady.com

Environmental Enforcement, Permits/Technical Review, Public Policy and
Communications on Air, Water and Waste Issues
and Community Environmental Protection

PO Box 39  East Lansing, MI  48826-0039
(517) 332-6971 (voice); (517) 332-8987 (fax)
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