United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-049 Apr. 1984
Project Summary
Evaluation of the Feasibility of
Incinerating Hazardous Waste in
High-Temperature Industrial
Processes
F.D. Hall, W.F. Kemner, G. Annamraju, R. Krishnan,
M. Taft-Frank, and D. Albrinck
In the search for disposal alternatives,
the U.S. Environmental Protection
Agency is evaluating the potential use
of high-temperature processes for the
incineration of hazardous waste. Many
kinds of waste have already been dis-
posed of in boilers and cement kilns;
this report considers the many other
potential processes, such as metallur-
gical furnaces, brick and lime kilns,
glass furnaces, and sewage sludge com-
bustors. Each process is examined
against such criteria as time/tempera-
ture profile, geographical location, pro-
duct quality considerations, institutional
factors, and environmental impacts.
Promising alternatives are identified.
This Project Summary was developed
by EPA's industrial Environmental Re-
search Laboratory, Cincinnati, OH, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The U.S. Environmental Protection
Agency (EPA) has a variety of ongoing pro-
grams to investigate, develop, and apply
incineration as a means for ultimate destruc-
tion of hazardous waste. One of these pro-
grams concerns the use of high-temperature
industrial processes. The first processes to
be investigated under this program were in-
dustrial boilers and cement kilns, which were
chosen partially because of their ubiquity and
partially because of the interest many boiler
and kiln operators expressed in recovering
the heating value of wastes. Presently,
several demonstration test burns are either
completed or underway.
Interest in other processes prompted EPA
to initiate a feasibility screening study for all
high-temperature processes. Such a study
would provide consistent and uniform criteria
for selecting those processes that offer feas-
ible combustion conditions and that should
be examined further for overall suitability.
Process Selection Criteria
The first task was to select common in-
dustries using high-temperature processes.
Table 1 summarizes the screening criteria
against which each process was evaluated.
The initial list of processes was based on
operating temperature; any major process
with an operating temperature of greater
than 650°C was included. The initial listing
of approximately 100 processes included the
metallurgical, chemical, and mineral in-
dustries and sludge and waste incinerators.
When the other criteria in Table 1 were ap-
Table 1. Screening Criteria for Potential
High-Temperature Processes for
the Destruction of Hazardous Wastes
Compatibility of process
- Thermal destruction conditions:
temperature and residence time
(turbulence not considered)
- Product quality
- Potential for fugitive emissions
Number of facilities
Geographic matching of industry location
and waste generators
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plied, several of these processes were
eliminated.
Gas residence time within the process at
the high-temperature condition was an im-
portant consideration; the lower the process
temperature, the longer the residence time
required for 99.99 percent thermal destruc-
tion. Turbulence, the other condition nec-
essary for combustion, was not considered
because little information is generally
available on this parameter for the processes
under consideration. Residence time and
product quality eliminated organic and mis-
cellaneous chemical manufacturing pro-
cesses from consideration. These processes
often attain high temperatures in reactors,
but residence times are quite short.
Product quality, both actual and per-
ceived, was an important consideration.
Destructing hazardous waste in a steel fur-
nace, for example, could increase trace
elements in the steel and affect its physical
properties. In all cases, hazardous waste
disposal was considered secondary to pro-
duct quality. This criterion eliminated pro-
cesses such as basic oxygen and electric arc
furnaces in the steel industry because these
processes produce a high-quality steel that
cannot tolerate residues from hazardous
waste destruction. This criterion also af-
fected chemical manufacturing, food pro-
cessing (human and animal consumption),
and petroleum refining processes.
The more potential a process has for
fugitive emissions, the less likely it is to be
suitable for hazardous waste disposal. Raw
materials handling procedures affect the
potential of a process for fugitive emissions
and for hazardous waste disposal. In a sinter-
ing process at an iron and steel mill, for ex-
ample,open conveyors are used to transport
raw materials to the pug mill (mixing device)
and to the sinter strand, which is also open.
Because of the major modifications to the
materials-handling system that would be re-
quired to correct this high potential for
fugitive emissions and because of the short
residence time at the maximum temperature
of about 1200°C, the iron and steel sinter-
ing process was eliminated from con-
sideration.
The number of facilities available in the
hazardous waste generation areas was
another major consideration. For example,
specialty processes that existed at only a few
widely scattered locations or developing pro-
cesses that were currently operational at only
a few sites were not considered. The pro-
cesses selected for detailed analysis were
those that had the potential for disposing of
significant quantities of hazardous wastes.
Table 2 lists those industries and processes
that remained after several processes had
been eliminated from further consideration
Table 2. Industries and Processes Selected for Further Hazardous Waste Destruction Evaluatk
Residence time
Industry
Brick
Carbon black
Primary copper
Primary lead
Primary zinc
Iron and steel
Lime
Lightweight
Process or furnace
Tunnel Kiln
Oil furnace process
Reverberatory furnace
Blast furnace
Multiple-hearth
roaster
Suspension roster
Fluidized-bed roaster
Blast furnace
Open hearth furnace
Long rotary kiln
Short rotary kiln
with stone preheater
Rotary kiln
Exit and maximum
temperatures, °C
260-1180
870-1400
1300-1400
700-1200
200-980
930-1010
950-1740
1100^-1870
1200-1800
680-1900
1160-1840
370-1150
/seconds, unless^
otherwise noted)
4.3
1.1
2.2
5.9
>JO
1.1*
2.0
8.3
7.6
3.6
aggregate
Gtass
Sewage sludge
Hazardous waste
**
incineration
Melting furnace
Fluid-bed furnace
Multiple-hearth
furnace
Rotary kin
Liquid injection
620-1480
760-870
480-980
820-1600
700-1650
4.1
1.4
0.5
2.0 s to
0.5 to 2
Residence time above the greater of the exit temperature or 760°C.
Represents estimated temperature at the top of the combusion zone in the blast furnace.
ttResidence time has been calculated using 33 percent of the total furnace volume.
Included for comparison only.
The residence time for solids and sludges can be adjusted.
§
by the application of the screening criteria.
These processes were evaluated in more
detail by use of a hazardous waste destruc-
tion model derived from an earlier model
developed by Acurex Corporation.1
Hazardous Waste Destruction
Model
The efficient destruction of hazardous
waste in any industrial process is primarily
dependent on the temperature and residence
time of the combustion products in the fur-
nace employed by the process. Hence, a
matching of the residence time-temperature
relationship for the industrial process with
that required for complete destruction
(99.99%) of the hazardous waste should
enable one to identify potentially destructi-
ble hazardous waste categories. Based on
kinetic data for the constituents in the
wastes, characteristic curves showing
various time-temperature combinations for
destruction of the wastes were obtained. For
the industrial process, knowing the furnace
volume, volumetric flow rate of gases, and
temperature range of the furnace made it
possible to plot "process curves" that
showed the residence time at which the fur-
nace gas is above a certain temperature
within the furnace. By laying the "process
curves" over the hazardous waste char-
acteristic curves, it was possible to estimat
the waste categories destructible at variou
temperatures. The required 99.99 percen
destruction is predicted for those waste
whose lines are below and to the left of th
process curves.
During a preliminary review, the wast
types produced by the following Industrie
were eliminated from consideration becaus
of their low destructibility by high-tempera
ture processes or their high explosion poten
tial: inorganic pigments, inorganic chemicals
explosives, iron and steel, and seconder
lead. Other wastes listed in the RCR/
Background Document2 were included in thi
model and grouped according to nonspecifii
sources (F series) and specific sources (I1
series). These categories were plotted accor
ding to the required temperature and tim<
for 99.99 percent destruction by use of th<
relationship:
, ( 9-21 \ E
/h At = /n( —
where:
At =
A =
RT
time required to reach
99.99 percent destruction, s
Arrhenius pre-exponent fre-
quency factor (s"1)
Energy of activation
(j/kg-mole)
-------
R = Universal gas constant
(8,314 J/kg-mole-°K)
T = Absolute temperature (°K).
Figure 1 shows the destruction lines for the
selected hazardous waste categories.
Process curves were overlayed on the
destruction lines to determine the hazardous
waste categories that should be considered
for destruction. These process curves were
calculated for the gas residence time above
specific temperatures by use of the follow-
ing calculation:
16,400 V T
t = In —
0-
-------
covery Act, Subtitle C; Background
Document. Office of Solid Waste,
Washington, D.C.
F. D. Hall, W. F. Kemner, G. Annamraju. R. Krishnan, M. Taft-Frank, and D.
Albrinck are with PEDCo Environmental. Inc.. Cincinnati. OH 45246.
Robert Mournighan and Laurel J. Staley are the EPA Project Officers (see
below).
The complete report, entitled "Evaluation of the Feasibility of Incinerating
Hazardous Waste in High- Temperature Industrial Processes." (Order No. PB
84-159 391; Cost: $22.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U.S. GOVERNMENT PRINTING OFFICE, 1984 — 759-015/7672
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
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