United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-086 July 1984
SEB\ Project Summary
Laboratory-Scale Flame-Mode
Hazardous Waste Thermal
Destruction Research
J. C. Kramlich, M. P. Heap, J. H. Pohl, E. M. Poncelet, G. C. Samuelsen,
and W. R. Seeker
This program was performed to gen-
erate fundamental flame-mode data on
the incinerability of hazardous waste
compounds. Other objectives included
the comparison of flame and nonflame
data, and the development of guidelines
for future work on the development of
an acceptable incinerability ranking
methodology.
Two reactor systems were selected to
provide flexibility in simulating the
failure conditions that can occur in liquid
injection incinerators. In the microspray
reactor the reaction characteristics of
single droplets of waste compounds
were studied. The turbulent flame re-
actor consisted of a swirl-stabilized
turbulent spray flame in which the waste
compounds were doped into an auxiliary
fuel. In this reactor the effect of flame
parameters such as stoichiometry,
atomization quality, and quench phe-
nomenon were studied. The approach
was to establish conditions that yielded
high destruction efficiencies, and then
to perturb the flame by changing one or
more flame parameters until incomplete
destruction occurred. The waste com-
pound concentration was then meas-
ured at the reader exit to establish the
ranking. Five test compounds were
utilized: acrylonitrile, benzene, chloro-
benzene, chloroform, and 1,2-dichloro-
ethane.
The results indicated that when oper-
ated under conditions of optimal com-
bustion efficiency flames were capable
of high waste destruction efficiency.
Under off-optimum conditions the
destruction efficiencies were typically
90-99.9 percent. No single ranking
procedure adequately described the
rankings observed under all conditions.
Rather, the flame rankings were
condition-dependent. These data indi-
cate that a realistic incinerability ranking
methodology must be a synthesis of
waste properties and system-dependent
parameters.
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
Permitting procedures for hazardous
waste incinerators are defined by the
Resource Conservation and Recovery Act
(RCRA). A permit to operate is issued after
a trial burn has been executed or other
appropriate test data obtained which
demonstrate that the incinerator satis-
factorily converts hazardous waste into
non-hazardous compounds .when oper-
ated under specified conditions. Satisfac-
tory conversion is defined in terms of
destruction and removal efficiency (ORE).
However, since most hazardous waste
streams contain many compounds, a trial
burn which involves the measurement of
all of them would be prohibitively expen-
sive. Consequently, the trial burn involves
the measurement of a subset of com-
pounds (the principal organic hazardous
constituents—POHC's) which are present
in the input stream. If the ORE of these
POHC's is 99.99 percent or greater, and
certain other conditions are met (e.g.,
chlorine and particulate matter removal
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and emissions standards), then a permit
to operate is granted. Thus, the burden of
responsibility rests with the permit writer
who must select the subset of compounds
(POHC's) based upon concentration and
incinerability. This constitutes the final
report of a project which was carried out
to examine methods of ranking incinera-
bility and to compare flame with nonf lame
waste destruction.
Several procedures have been proposed
to rank incinerability, namely:
• The heat of combustion.
• Autoignition temperature (AIT).
• A computational approach based upon
AIT, compound structure, and other
compound-dependent parameters.
• The temperature necessary for a given
destruction level within a given time
under dilute premixed conditions
(Tgggg).
• Susceptibility of the compound-bound
structure to attack by flame radicals.
These procedures have their merits, but
fail to take into account all the conditions
which may exist in actual incinerators.
The heat of combustion, for example, of a
particular compound maybe insignificant
if it is present in small quantities and is
mixed with an auxiliary fuel. In addition,
some of these procedures do not consider
processes and reactions that occur in
flames. The times and temperatures
which exist under nonflame experimental
conditions may be inappropriate for large-
scale diffusion flames.
The concept of incinerability is used to
describe the relative degree of difficulty of
incineration of the various hazardous
organic constituents present in a given
waste stream. If, during the trial burn, it is
demonstrated that compounds most diffi-
cult to destroy have a ORE greater than
99.99 percent, then it is assumed that
compounds ranked more incinerable
under the accepted hierarchy will be
destroyed at the same or greater ORE
than the difficult compounds. Thus, there
is a need for some ranking methodology
that will aid the permit writer in his
selection of difficult compounds. If the
ranking methodology is in error, or is not
applicable to a particular system, then a
condition could exist wherein a POHC
was destroyed satisfactorily, but other
hazardous compounds in the waste
stream were not destroyed sufficiently.
Under these circumstances, a trial burn
designed to measure only the POHC may
have incorrectly demonstrated the satis-
factory operation of the incinerator.
Because of the nature of flames, waste
compounds which experience a flame
environment are rapidly and completely
destroyed. This can be demonstrated by
considering nonflame thermal decompo-
sition data obtained under dilute premixed
conditions. As an example, nonflame data
indicates that chlorobenzene will decom-
pose to 99.99 percent of its original
concentration in 1 sec at 1038°K. At
typical flame temperatures (approximately
2000°K), the time required to obtain the
same destruction level is much smaller
(<10~13 sec. using the same thermal
decomposition data) than the typical 0.10
sec. flame residence time.
Thus, nonf lame thermal decomposition
data obtained under dilute premixed
conditions indicate that temperatures
much lower than those encountered in
typical incinerator flames will destroy all
the organic hazardous waste compounds
which have been tested to date. Also,
because of high reactant concentrations
in flames, free radicals which must be
present to propagate the flame will con-
tribute to destruction of the compounds in
the flame. These free radicals will in-
crease the rate of decomposition above
those predicted from dilute decomposition
kinetics. Under ideal flame conditions, in
which all of the waste is exposed to flame
temperatures, the concept of incinerabil-
ity has little significance since all haz-
ardous compounds would be expected to
be completely destroyed.
Incomplete destruction of a hazardous
waste compound in an actual incinerator
must be caused by conditions that allow
some of the material to escape or bypass
the flame, since organic compounds are
destroyed rapidly in a flame environment.
Most incinerators include long residence
time hold-up zones or afterburners to
destroy material that has not completely
reacted in the flame zone. Thus, inciner-
ability would be expected to be influenced
not only by the chemical properties of the
compound, but also by its physical pro-
perties and their interaction with the
incinerator operating conditions because
these may influence the failure mode.
The term "failure mode" is used to
describe those conditions that might
occur in a practical incinerator, which
preclude complete processing of the
waste material by a high-temperature
turbulent diffusion flame. Thus, the term
in the present context does not include
conditions that may affect other parts of
an incinerator (e.g., afterburner or scrub-
ber). It is important to evaluate inciner-
ability under conditions that simulate
those failure modes which could occur in
practice.
Various phenomena account for the
failure of turbulent diffusion flames,
typical of those used in liquid injection
incinerators, to completely destroy a liquid
waste. The destruction efficiency in the
flame maybe less than quantitative (100
percent) because of any of the following
reasons:
1. Atomization Parameters. When the
waste material is injected as a liquid
that must be atomized, poor destruc-
tion efficiency can result from inap-
propriate atomization. (a) Droplets
that are too large to evaporate may
be produced, (b) Their trajectory
may be such that they penetrate the
flame zone and ignition does not
occur, (c) Droplets that are too small
may promote concentrated evapora-
tion zones which produce fuel-rich
pockets.
2. Mixing Parameters. In a turbulent
diffusion flame the reactants are
supplied separately and reactant
contacting takes place via turbulent
mixing. Poor mixing can result in
low destruction efficiencies be-
cause the waste material may not
be mixed with oxygen before it
escapes from the flame region.
3. Thermal Parameters. The destruc-
tion efficiency may be low because
flame temperatures are too low.
This can occur if the calorific value
of the waste/auxiliary-fuel mixture
is low or heat removal rates are
high.
4. Quenching Parameters. The reac-
tants can be quenched before
destruction is complete by hetero-
geneous or homogenous phenom-
ena. Quench rates are high due to
mixing with excessive excess air
levels in fuel injection systems in
which the flame impinges on an
aqueous jet, or the flame may
contact a relatively cool surface.
Consequently, it is essential to investigate
the concept of incinerability in flames
under conditions that could account for a
failure to completely destroy the waste
compound and under conditions that are
typical of real systems.
The primary goal of this study was to
compare the proposed incinerability rank-
ing procedures with those measured
under flame conditions typical of liquid
injection incinerators. The approach util-
ized was to measure the exhaust com-
-------
pound concentration under different
simulated failure modes and to compare
the ordering of the compounds to those
given by several incinerability ranking
procedures. Two reactors were required
to simulate failure conditions for all the
parametersexpected to influence inciner-
ator performance; i.e., thermal atomiza-
tion, mixing, and quenching. A microspray
reactor consisting of a laminar premixed
flat-flame into which test compounds
were injected was used to investigate
thermal parameters. Asubscale turbulent
diffusion spray flame was used to investi-
gate atomization, mixing, and quenching
parameters. Secondary goals included
the generation of fundamental flame-
mode destruction data necessary to com-
pare flame and nonflame decomposition.
The results are primarily a means of
guiding future experimental work, since
further work is necessary to select a
reasonable ranking protocol.
Experimental Approach
Extensive investigations are being
carried out at the University of Dayton
Research Institute under EPA sponsorship
to define the kinetics of waste decomposi-
tion in post-flame regions. The emphasis
of the present study was on the flame
zone itself and the impact of failure
conditions associated with mixing, ther-
mal, quenching, and atomization param-
eters on the relative destruction of five
compounds. These compounds were
selected because they represented a
broad range of incinerability asdefined by
existing ranking procedures, and because
data within each of the procedures were
available for the compounds. The study
was restricted to conditions typical of
liquid injection incinerators. No attempt
was made to include phenomena associ-
ated with waste destruction in beds such
as those that exist in fluidized beds, rotary
kilns, or hearth incinerators. Two flame
reactors were used to study destruction
efficiency under different conditions:
1. Microspray Reactor. In the micro-
spray reactor, monodisperse waste
droplets were injected into a hot,
uniform post-flame gas. These ex-
periments investigated the destruc-
tion efficiency (DE) behavior and
ranking that resulted from individ-
ual droplet evaporation and flame
decomposition reactions. The exper-
iment was designed to bridge the
gap between the nonflame thermal
decomposition experiments and the
turbulent flame data. As such, it
included two processes in addition
to the thermal decomposition exper-
iments: droplet vaporization dynam-
ics and flame reactions. The data
were used for the following pur-
poses:
• To determine what portion of the
turbulent flame rankings was
due to laminar flame and evapo-
ration processes.
• To compare flame (microspray)
with nonflame (thermal decom-
position) destruction on a funda-
mental level without the compli-
cating influence of turbulence.
2. Turbulent Flame Reactor. A turbu-
lent flame reactor (TFR) was used to
investigate DE and ranking in a
turbulent spray diffusion flame. The
TFR was operated under conditions
to simulate many of the processes
occurring in the flame zone of a
liquid injection incinerator; these
could be exaggerated to simulate
different failure modes.
Five compounds (chloroform, acryloni-
trile, benzene, chlorobenzene, and 1,2-
dichloroethane) were selected as repre-
sentative of liquid organic hazardous
wastes. All the compounds are listed in
the 1980 RCRA regulations. Part 261,
Appendix VIII (Federal Register. May 19,
1980). The compounds were chosen to
represent a broad range of incinerability
based on the most commonly proposed
ranking procedures. They cover greater
than 90 percent of the range in heats of
combustion for the listed compounds (. 13
to 10.14kcal/gm). Since a direct compar-
ison between nonflame thermal decom-
position rankings and the flame-mode de-
struction was an objective of this study,
compounds were selected for testing for
which nonflame data were available. In
addition, the selection also took into
account the NBS ranking system, a range
of autoignition temperatures and a variety
of molecular structures. Two compounds,
a highly chlorinated methane and a
chlorinated ethane, are aromatic; another
compound contains nitrogen.
Compound DE was measured in the
reactor exhaust by adsorption onto Tenax-
GC, followed by thermal desorption and
flame ionization gas chromatographic
analysis. The use of Tenax for concentra-
ting the sample provided the necessary
rapid turnover of samples with sufficient
separation and sensitivity. The break-
through volumes of all the test compounds
were directly measured and were found
to be greater than the utilized sample
volumes. Benzene and 1,2-dicloroethane
were not separable by the column and
hence mixtures containing both com-
pounds were avoided.
Microspray Results
The microspray was used to investigate
the impact of thermal parameters for two
conditions:
• Fuel-lean—excess oxygen available to
oxidize test compounds.
• Fuel-rich—insufficient oxygen avail-
able to oxidize test compounds.
In addition, the effect of using pure
compounds was compared with that for
mixtures of compounds. The other failure
mode parameters (atomization, quench-
ing, and mixing) cannot be effectively
investigated in the microspray reactor
and were investigated in the turbulent
flame reactor.
Figure 1 presents data for two mixtures
of four compounds shown separately in
Figures 1(a) and 1(b). In these tests, 38
//m droplets of the two mixtures were
injected separately into a lean (10 percent
excess oxygen) Ha/air/IVU flame with
different flat-flame temperatures. Ex-
haust concentrations of the individual
test compounds were measured and the
data are shown in Figure 1 in terms of the
fraction of each compound remaining
versus the measured flat-flame tempera-
ture. This temperature is determined by
extrapolating the axial temperature
measurements to the burner face and is
the highest temperature of the flat-flame
gas. Under these excess oxygen condi-
tions, flames were observed to surround
each individual droplet for both mixtures
for flat-flame temperatures in excess of
850°K. However, the minimum droplet
ignition temperature was observed at
slightly lower temperatures for the 1,2-
dichloroethane mixture, probably due to
the substitution of compounds. When the
flat-flame temperature is greater than the
ignition temperature of the specific com-
pound mixture, the exhaust concentration
of the test compounds were below the
detection limit of the analytical technique
which indicated a destruction level in
excess of 99.995 percent.
Calculations using nonflame kinetics
indicate that almost no decomposition
should occur below 800°K for the resi-
dence times (~1 sec.) available in the
microspray reactor. However, as shown
in Figure 1, significant destruction was
measured at flat-flame temperatures
below 800°K. This destruction at low flat-
flame temperatures is probably due to a
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(stoichiometric ratio = 0.83} H2/air/N2
flames of different temperatures. In these
tests, the oxygen was rapidly and com-
pletely consumed by the hydrogen in the
flat-flame so that no oxygen was available
to oxidize the test compounds. The frac-
tion of each compound remaining in the
exhaust as a function of the flat-flame
temperature is shown in Figure 2. Even
with mixtures, the temperature, 1050°K,
required to destroy the compounds was
found to be very similar to the 199.99
temperatures of the individual compounds
(920 to 1037°K); and were much higher
than those required if droplet ignition
occurred (Figure 1). The fractional de-
struction was strongly dependent upon
flame temperature. In fact, the data show
that a very small change in flame temper-
ature above 1050°K produced a substan-
tial change in the compound concentra-
tions, particularly for benzene. A difference
between the compounds was observed
only at a temperature just below the flat-
flame temperature required for complete
destruction. At that temperature, the
compound that was most predominant
was chlorobenzene, followed by benzene,
chloroform, and acrylonitrile. This ranking
was identical to that measured for the low
temperature oxidation data (Figure 1).
The nonflame Tgg.gg did identify the
temperature range required for complete
destruction and the most predominant
compounds (chlorobenzene and benzene);
however, acrylonitrile and chloroform are
reversed from the T98.gg ranking.
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Figure 2. Fraction of test compound re-
maining in exhaust when 38 fjm
droplets of mixtures of com-
pounds were injected into rich
(stoichiometric ratio = 0.83)
Ht/air/Nz flame as a function of
flame temperature. Incinerabil-
ity order at 1050°K (highest to
lowest concentration) is chloro-
benzene, benzene, acrylonitrile,
and chloroform.
Turbulent Flame Reactor Results
The turbulent flame reactor was oper-
ated and tested under a number of
conditions. However, many of these condi-
tions resulted in high destruction effi-
ciency of all the test compounds. Only
those parameters resulting in significant
deterioration of destruction efficiency are
presented. The conditions investigated in
the turbulent flame reactor that had a
strong influence on destruction efficiency
were primarily associated with three
failure parameters:
• Atomization parameters—poor atom-
ization quality.
• Combustion parameters—high excess
air
—low excess
air
—low heat
release
• Mixing (or turbulence)—swirl
—air velocity
Those parameters found to be of less
importance included burner velocity, fuel
type (No. 2 fuel oil), and concentration of
hazardous waste compounds (from 3 to
25 percent).
It was generally found that exhaust
concentration measurements of carbon
monoxide (CO) and total hydrocarbons
were good indicators of flame perform-
ance and compound destruction effici-
ency. The exhaust CO level in particular
appeared to be well correlated with the
exhaust concentration of the test com-
pounds. This result was expected since
the high heat removal rates in the TFR
emphasize flame performance over post-
flame reaction. Since CO is an inter-
mediate in the oxidation of hydrocarbons
to carbon dioxide (CO2), it is directly linked
with combustion efficiency. Therefore, an
examination of the relative CO levels for
each failure condition indicates the overall
combustion efficiency which can be com-
pared to the destruction efficiency of the
hazardous waste compounds. The rela-
tionship between exhaust CO, total hydro-
carbons measured by the flame ionization
detector, and destruction efficiency
measured for a mixture of compounds is
shown in Figure 3. The maximum ORE
O99.995 percent) was measured at 30-
40 percent excess air, which corre-
sponded to the minimum in both exhaust
CO and hydrocarbon.
Figure 4 presents data obtained with
the TFR at high heat-release rates (44
kW). Very high destruction levels
O99.995 percent) were measured for all
compounds at 20 percent excess air at
this heat-release rate with the exception
of benzene. It is possible that benzene
was a product of incomplete combustion
of either the auxiliary fuel or one of the
test compounds (e.g., chlorobenzene). The
actual source of the benzene, whether it
is a product of incomplete combustion or
an indication of incomplete benzene
destruction, has not been determined.
Benzene is a possible intermediate in the
formation of soot which was observed in
the flame in the form of luminosity,
especially at low excess air levels. Be-
cause of the relatively large amounts of
heptane present (97 percent), only a small
conversion of heptane to benzene is
required to account for the exhaust levels
of benzene measured at this low excess
air condition. However, the benzene could
also be the result of a chlorobenzene
reaction.
At higher excess air levels (>150
percent) theoretical air, the exhaust con-
centrations of CO and the test compounds
increased. This is probably due to lower
flame temperatures and increased quench-
ing, which can occur when large amounts
of unheated air are present. The lowest
ORE level obtained for these heat-release
rates (44 kW) was 99.9 percent. The
compound differences were small but
measureable at 150 percent theoretical
air. The ranking from highest to lowest
concentration was: chloroform, acryloni-
trile, benzene, and chlorobenzene. This
particular order, which was found to exist
for a number of failure conditions tested
with the turbulent flame reactor, does not
agree with any of the proposed rankings,
although the heat of combustion did
identify the most predominant compound
(chloroform).
The data obtained at low heat-release
rates (24-42 kW) are shown in Figure 5.
This data set was achieved by lowering
the fuel flow rate from the nominal
operating conditions, while maintaining
the air flow constant. This drop in load
and increase in theoretical air resulted in
a significant increase in the fraction of
waste compounds in the exhaust. Under
this failure conditions, chloroform and
benzene had similar high exhaust concen-
trations, followed by 1,2-dichloroethane
and similar low exhaust concentrations
for acrylonitrile and chlorobenzene.
The data presented in Figure 6 indicate
that atomization parameters had signifi-
cant impact upon compound destruction.
In these tests, a nozzle designed for 1.5
gal/min was operated at .75 gal/min
dropping the pressure from 161 psigto40
psig. This increases the mean droplet
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99.995 percent) de-
stroyed. Even in the absence of oxygen,
the microspray data were consistent with
the high destruction efficiencies achiev-
able in a turbulent diffusion spray flame
environment.
The TFR was operated at high heat
removal rates by operating with water-
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Under all failure conditions investigated,
exhaust CO concentration increased
when the test compound concentration
increased. These results suggest the
feasibility of using exhause CO and
potentially total hydrocarbons to monitor
the performance of liquid injection incin-
erators once the conditions giving the
maximum destruction efficiency have
been defined.
The incinerability or ordering of the
compounds was found to depend on the
actual failure condition which caused the
inefficiency. When both the microspray
and the turbulent flame reactor were
operated under conditions that simulated
failure modes of practical incinerators,
measurable differences in the destruction
efficiency of the five test compounds
were obtained. For example, chloroben-
zene was the most difficult to eliminate in
the microspray when the temperature
was too low to ignite the droplets, but was
the least difficult to eliminate for a variety
of failure conditions in the TFR, such as
poor atomization quality.
Figure 8 presents a series of bar graphs
which allow a comparison between incin-
erability as defined by the various failure
modes and the rankings indicated by
procedures based upon Tgggg, heat of
combustion, the NBS method, and AIT.
The bar graph shows the concentrations
measured in the experiment normalized
so that the most predominant compound
shows full-scale and the lesser concen-
trations are expressed as a percentage of
that maximum concentration. This ap-
proach gives an indication of the meas-
ured magnitude of the difference in
destruction efficiency between com-
pounds. A comparison of these relative
concentration measurements with pro-
posed incinerability ranking techniques
demonstrates that none of the proposed
techniques agree with the data for all
failure conditions. However, some of the
ranking procedures were found to be
appropriate for specific failure conditions.
For example, the nonflame thermal de-
struction (Tgg.gg) and AIT procedures both
agreed with the compound concentration
measurements when the temperature
was below droplet ignition temperature
and under oxygen-deficient conditions.
Heat of combustion was found to correlate
the pure compound data when the micro-
spray was operated below droplet ignition
temperature. In most instances, chloro-
form was the most difficult compound to
incinerate for the failure conditions
investigated with the TFR, and this was
anticipated by only one of the four ranking
techniques: heat of combustion.
8
Although measurable differences in the
destruction efficiency of the five test
compounds were obtained, the differ-
ences were not large under any of the
conditions tested. For the most part, the
variation in the concentration (between
highest and lowest) of the compounds in
the exhaust was typically of the order of
five, although variations larger than ten
were measured under some circum-
stances. This suggests that the selection
of POHC may not be very critical because
the differences between compounds are
small. If the permit writer selects three
compounds based upon two or more
ranking techniques, and it is demonstra-
ted that their ORE is greater than 99.99
percent, then it is very unlikely that any
other compounds will be destroyed to a
significantly lesser degree.
This study has identified the differences
between compound destruction efficiency
caused by failure conditions associated
with the flame zone. High destruction
efficiencies have been demonstrated in
the flame alone. However, many inciner-
ators are equipped with post-flame hold-
up zones and afterburners in order to
achieve additional thermal decomposition
of compounds which escape the flame
zone. In order for an incinerator to fail to
destroy a compound, the material must
both escape the flame and the tempera-
ture be too low in the post-flame hold-up
zone to destroy the compound (less than
Tgg.gg). The differences in the concentra-
tion of compounds in the exhaust of the
incinerators is associated with both the
flame and nonflame zones. The thermal
decomposition which occurs in the post-
flame zone can alter the ranking in the
exhaust. As an example, consider a flame
zone in which the DE of chloroform and
chlorobenzene was 95 percent and 99
percent, respectively (a flame ranking
consistent with the data of Figures 6 or 7).
Utilizing nonflame kinetics and a 1.0 sec
isothermal post-flame zone for post-flame
temperatures below about 870°K, the
flame zone ranking will persist in the
exhaust. Above 1008°K both compounds
are destroyed to 99.99 percent DE. Hence,
there are potential situations, dependent
on incinerator conditions, for either a
flame zone or a post-flame ranking to
prevail within a given unit.
It was not the purpose of this study to
ascertain why destruction efficiency
under flame conditions can be compound
and failure mode specific. More detailed
measurements, such as fundamental
kinetic flame studies, are necessary to
provide a full explanation of the causes of
the rankings. It could be associated with
flame inhibition due to the presence of
halogens, which are known to reduce
burning rates. Under quenching condi-
tions, these effects could be enhanced.
The formation of products of incomplete
combustion (PIC's), as a consequence of
the partial destruction of the waste
compound, was not investigated. An
alternate method of assessing inciner-
ability could be based upon the potential
to form PIC's, which are themselves
hazardous.
Conclusions
1. Under optimum conditions, flames
are capable of destroying hazardous
waste compounds with very high
efficiencies (greater than 99.995
percent) without the need for long
residence time, high-temperature
post-flame zones, or afterburners.
2. Reduced flame destruction effici-
encies are the result of operation
under some failure mode, such as
poor atomization, poor mixing, or
flame quenching.
3. Incinerability, or ordering of com-
pounds in terms of their relative
destruction efficiency, is dependent
on the actual failure condition
which caused the inefficiency.
4. Optimum conditions for destruction
of hazardous waste compounds in
turbulent diffusion spray flames
correspond to minimal exhaust CO
and total hydrocarbons.
5. No one incinerability ranking sys-
tem appears to predict correctly the
relative destruction efficiency of the
five compounds tested for all failure
conditions investigated. However,
several rankings did correctly pre-
dict relative DE for specific failure
conditions.
6. More data are required on other
compounds and on other failure
conditions more appropriate to dif-
ferent types of hazardous waste
incinerators to fully determine the
limitations of incinerability ranking
systems and to develop an appro-
priate incinerability ranking meth-
odology.
7. Future experimental effort should
be directed toward extending the
compound data base beyond the
current five, and in particular, the
extension of experimental capabil-
ities to consider additional failure .
modes (e.g., those associated with (
post-flame thermal processes of
afterburners).
-------
ncinerability Rankings
Chloroform
1 2 Dichloroethane
Benzene
Acrylonitrile
Chlorobenzene
Microspray
Chloroform
1,2 Dichloroethane
Benzene
Acrylonitrile
Chlorobenzene
Turbulent Flame
Chloroform
1,2 Dichloroethane
Benzene
Acrylonitrile
Chlorobenzene
Turbulent Flame
Chloroform
1,2 Dichloroethane
Benzene
Acrylonitrile
Chlorobenzene
Non-Flame
Temperature
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1
Figure 8. Comparison of proposed ranking techniques and concentration measured in the experiments under flame failure conditions normalized
so most predominant compound shows full scale.
-------
J. C. Kramlich, M. P. Heap. J. H. Pohl, E. M. Poncelet, G. S. Samuelson, and W. R.
Seeker are with EERC, Irvine, Ca 92714-4190.
C. C. Lee is the EPA Project Officer (see below).
The complete report, entitled "Laboratory-Scale Flame-Mode Hazardous Waste
Thermal Destruction Research," (Order No. PB 84-184 902; Cost: $16.00,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
•U9GPO: 1984-759-102-10618
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