[Dioxin-l] Question

[Alex J. Sagady & Associates]

At 05:39 PM 01/19/2000 -0500, you wrote:
>Hello all.
>
>I have a question about tire incineration and the incineration of
>hazardous waste in cement kilns.
>
>Are these two practices fundamentally unsafe compared to municipal, or
>even medical waste incineration?

There is a very useful review of this issue (on hazardous waste) published 
on the
web site of the American Lung Association at
http://www.lungusa.org/air/recycle/index.html

You may also want to review work done recently by the
National Research Council on hazardous waste incineration.

The fundamental problem with cement kiln hazardous waste
incineration is that it has the effect of putting 100% of the toxic
metals found in hazardous waste into the environment, either as
clinker, cement kiln dust or air pollution.  Mercury control is particularly
poor at cement kilns.

Some cement kilns, both ordinary kilns burning just coal and petroleum
coke and others that burn these fuels plus hazardous waste, have
been high PCDD/PCDF emitters.   This is in addition to hazards
these facilities pose from poor control of fugitive dust emissions.

Most hazardous wastes that are combusted  (about 65-70%) in the United 
States are
burned in cement kilns, primarily at facilities in Missouri, Kansas,
South Carolina, North Carolina, Michigan, Indiana, and Texas.   Marine shale
has been trying to restart its waste burning in Louisiana but, to the
best of my knowledge, they haven't yet restarted.   Now known at GTX,
they were the largest burner in the US.   Pennsylvania had two facilities
but both stopped burning.   When it was burning waste, the Medusa
facility in Wampum PA almost certainly discharged far more PCDD/PCDF
than WTI in Ohio.

Mass emissions of certain toxicants from cement kilns are permitted to be 
higher
than the same emission permitted from hazardous waste incinerators.
Environmental organizations have challenged these regulations in
court.

On the issue of burning tires in cement kilns.......   some emissions
go up and some go down, depending on the fuel the tires are replacing.
The success or failure of using tires  or tire derived fuels
in cement kilns depends in part on how this practice is carried out, the
nature of the combustion regime in the pre-existing kiln, the type of
kiln used, where the tires/TDF is inserted and the type of air pollution
controls.  Each situation will be different.

There was kiln site in California where commencement of tire burning lead
to a big increase in PCDD/PCDF.   Other sites have shown decreases of
both metals, criteria pollutants and sulfur dioxide.....all depending on 
the situation
and the types of fuels being replaced.   Poor combustion of tires can
generate a lot of toxic organic compounds.   But TDF is expected to
generate lower metal emissions, with the exception of chromium and zinc,
compared to coal or petroleum coke it would replace..

There is a 1997 report on both uncontrolled tire fires and TDF combustion
in boilers and kilns.   EPA generally endorses the practice.  See....

http://www.epa.gov/ttncatc1/dir1/tire_eng.pdf

Situations to avoid....

....charging tires chunks along with raw kiln feed in cement kilns
    (allows poor combustion of tire materials prior to full heating.

Charging tires to the center of kilns that have poor combustion  and high 
carbon monoxide
problems at the cool end from use of shale or high kerogen limestone.

Charding tires at a location in a pre-heater, pre-calciner kiln in a
way that allows products of incomplete combustion to go out
alkali bypass stacks on kiln 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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