vvEPA
United States
Environmental Protection
Agency
EPA/540/S5-89/007
April 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Technology Demonstration
Summary
Shirco Pilot-Scale Infrared
Incineration System at the Rose
Township Demode Road
Superfund Site
Under the Superfund Innovative
Technology Evaluation or SITE
Program, an evaluation was made of
the Shirco Pilot-Scale Infrared
Incineration System during 17
separate test runs under varying
operating conditions. The tests were
conducted at the Demode Road
Superfund site in Rose Township,
Michigan using 1,799 kg (3,967 Ib) of
soils contaminated with poly-
chlorinated biphenyls (PCBs) and
other organics, and lead and other
heavy metals. The report includes a
process description of the unit, unit
operations data, sampling and
analytical procedures and data, and
an overall evaluation of performance
and energy consumption.
The Shirco Infrared Incineration
System uses electricity for infrared
heating rods which heat the soil and
desorb or incinerate the organic
contaminants, followed by a conven-
tional, propane-fired combustion
chamber to complete the destruction
of gaseous organic compounds. The
system was evaluated for
effectiveness in removing and
destroying organic contaminants and
reducing the mobility of metal
contaminants under both standard
and varied operating parameters. The
achievement of applicable regulatory
standards and the effect of operating
conditions on energy consumption
were also assessed.
The results show that the unit
achieved destruction and removal
efficiencies (DREs) for PCBs
exceeding 99.99%, based on
detection limits. Several semivolatile
and volatile organic compounds were
measured in the stack gas at very low
levels (parts per billion) and may be
products of incomplete combustion
(PICs). The unit achieved regulatory
standards for acid gas removal and
particulate emissions. Levels of
residual PCBs in the furnace ash
were less than 0.2 ppm under most
unit operation conditions. The
majority of the heavy metals
remained in the furnace ash, but
there was no evidence of a decrease
in the mobility of lead as a result of
treatment. Also, residual heavy
metals were measured in the
scrubber water effluent. The
optimization of the heat content of
the waste, retention time, and primary
combustion chamber temperature
can significantly reduce energy
consumption and cost.
-------
This Summary was developed by
EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to
announce key findings of the SITE
Program demonstration that is fully
documented in two separate reports
(see ordering information at back).
Introduction
In response to the Superfund
Amendments and Reauthorization Act of
1986 (SARA), the Environmental
Protection Agency's Office of Research
and Development (ORD) and Office of
Solid Waste and Emergency Response
(OSWER) have established a formal
program to accelerate the development,
demonstration, and use of new or
innovative technologies as alternatives to
current containment systems for
hazardous wastes. This new program is
called Superfund Innovative Technology
Evaluation or SITE. The principal goal of
the SITE program is to demonstrate new
technologies in the field and develop
reliable economics and performance
information.
The SITE program demonstration of
the Shirco Pilot-Scale Infrared Incin-
eration System for thermal treatment
developed by Shirco Infrared Systems,
Inc. of Dallas, Texas, was conducted at
the Demode Road Superfund Site in
Rose Township, Michigan. The Demode
Road site is a 12-acre waste site
previously used to bury, dump, and store
industrial wastes such as paint sludges,
solvents, and other wastes containing
PCBs, oils and greases, phenols, and
heavy metals . PCBs and lead are the
principal contaminants in the soil used for
the test of the Infrared System.
The test was conducted from
November 2-13, 1987 and treated 1,799
kg (3,967 Ib) of contaminated soil under
various test conditions. The major
objectives of this demonstration were to
determine the following:
ORE levels for PCBs and the presence
of PICs in the stack gas. The regulatory
standards are 99.99% ORE under the
Resource Conservation and Recovery
Act (RCRA) and 99.9999% ORE under
the Toxic Substances and Control Act
(TSCA).
Level of hydrogen chloride (HCI) and
particulates in the stack gas. The
RCRA standard for HCI in the stack
gas is 1.8 kg/hr (4 Ib/hr) or 99 wt% HCI
removal efficiency. The RCRA standard
for paniculate emissions in the stack
gas is 180 mg/dscm (0.08 gr/dscf).
Level of residual PCBs in the furnace
ash at normal and varied operating
conditions.
Mobility of heavy metals, particularly
lead, in the furnace ash as compared to
the feed.
Mobility of heavy metals in the furnace
ash as compared to the RCRA
Extraction Procedure Toxicity (EP Tox)
Characteristic (as measured by the EP
Tox test) and the proposed Toxicity
Characteristic (as measured by the
Toxicity Characteristic Leaching
Procedure (TCLP)).
Level of residual heavy metals and
organic compounds, and other physical
and chemical characteristics in the
scrubber water discharged from the
unit.
The operating conditions that reduce
energy consumption without
decreasing soil decontamination
effectiveness.
Effect of varying operating conditions
on residual levels of heavy metals and
organics in the furnace ash versus the
levels in the feed.
Adherence of the quality assurance
(QA) procedures to the requirements of
the RREL approved QA Project Plan
(Category II), as defined by the
Document No. PA QAPP-0007-GFS,
"Preparation Aid for HWERL's
Category II Quality Assurance Project
Plans", June, 1987.
Feed Preparation
The demonstration test used soil from
an area of the site that was highly
contaminated with PCBs and lead, as
determined in the original remedial
investigations performed at the site.
Pretest sampling and analysis further
identified those sectors within the area
most highly contaminated with PCBs and
lead for excavation. Other organics and
heavy metals were also present in these
sectors. Soil from these sectors to be
used as feed for the test was excavated
and mixed into a pile using a front-end
loader, and then screened to remove
aggregate and debris greater than one
inch in diameter. The screened soil was
drummed and transferred to a designated
zone adjacent to the test unit. Two drums
of soil were blended with 3 wt% fuel oil to
be used for several of the test runs to
investigate the effect of increased feed
heating value on overall unit performance
and energy consumption at varying
operating conditions.
Process Description
The Shirco Pilot-Scale Infrared
Incineration System consists of a waste
feed system, an (electric) infrared
primary combustion chamber, a supple-
mental propane-fired secondary combus-
tion chamber, a venturi scrubber
emissions control system, an exhaust
system, and a data collection and control
system, all enclosed in a 45-ft trailer. The
system process flow and the overall 250
ft x 100 ft test site layout are presented
schematically in Figures 1 and 2,
respectively.
During the test, the feed material was
transferred from the drums to pails,
weighed, and then fed manually to a
hopper mounted over a metering
conveyor belt. The waste was fed at a
controlled rate through a sealed feed
chute onto the incinerator conveyor (a
tightly woven wire belt which moved the
waste material through the primary
combustion chamber). The conveyor belt
speed can be adjusted to achieve feed
residence times in the PCC from 6 to 60
min. Typically residence times range
from 10 to 25 min. The depth of the
waste on the conveyor belt ranged from
one to one and a half inches.
The primary combustion chamber
(PCC) is a rectangular box insulated by
layers of ceramic fiber. Combustion air is
supplied to the primary combustion
chamber through a series of air ports at
points along the length of the chamber .
The gas flow in the incinerator is
countercurrent to the conveyed feed
material. Electric infrared heating
elements installed above the conveyor
belt heat the waste to the designated
temperature (nominally 1600°F), which
results in desorption or incineration of
organic contaminants from the feed.
Rotary rakes gently turn the material to
ensure adequate mixing and complete
desorption. When the thermally treated
soil, now referred to as furnace ash,
reaches the discharge end of the PCC, it
drops off the belt through a chute and
into an enclosed hopper and discharge
storage drum. The drums of furnace ash
are then stored for final disposal.
Exhaust gas containing the desorbed
contaminants exits the primary
combustion chamber into a secondary
combustion chamber (SCC) or
afterburner, where a propane-fired burner
combusts residual organic compounds
into C02, CO, HCI, and H20. The SCC is
typically operated at 2200°F and a gas
residence time exceeding 2 sec.
Secondary air is supplied to ensure
adequate excess oxygen levels for
-------
Fencing
X X
Exclusion Zone
Drum Storage Area
Waste Feed
Ash
Slowdown Water
Empty Drums
Shirco Pilot-Scale Demonstration Unit Trailer
Waste Feed
Transfer
Drums to
Pails
PCC to SCC Vapor Duel
SCO Vapor Outlet Ducf
Burner Forced
Air Blower
Control Cabinet
Belt Speed Control
Burner Control
Light Panel
Motor Control Center
Transformer
Electrical Service
HEPC
Waste Feed
Weigh Scale
Secondary Combusiton Chamber
Primary Combustion Chamber
t t Alt t
Induced
Draft
Fan
' Combustion^
Air Blower
/Propane /
Fuel
Supply
/ Scrubber f
Blowdown
Drum
Contamination '
Reduction \
Zone
/ / / /
At Grade
Makeup Water
from Water
Supply Trailer
Figure 1. System process flow.
-------
To Fenced
Hazardous
Waste Site
Fencing
^?
&
p?^
\Zf-tZ-
^=5=1
I.
c5^''v
*^>">',
P0
p?^
ii
^li^ss?-'"
Waste Feet/
Transfer
Drums to
Pails ^
Waste Feed
Weigh Scale
jg-^gi^H*!^
Exc/u
lUl
III
m
»
lHHP
sionZone
&Z^ f^:'-^^%2?%%^%^.
!^
II
1
|p Drum Storage Area ^
^ Waste Feed ?r
"P /4sn
^ Slowdown Water .,
^ Empty Drums
^%5^
^
^
Sfiirco Pi/ot-Sca/e Oemonsfrafion
t/n/f Trailer
I
Clean Zone
T,
i .,
I Contamination ,
I Reduction \
\ Zone j
Electrical
Supply-
Diesel
Generators
Radian Analytical
Trailer
X
x
x
' '
1 1
1 /
' 1 1
I
I
I
I
X
X
L.
-X X XX X-
Fencing
^^
I
*s
X-
- ,
j
:
>
>
}
9
5
-
^
v\ CL
< / '
/ /
< f
/ /
( ' /
/ /
' / /
e / /
c / /
/ '
< / /
1 / /
f / from S/'re
/
Meteorological
Station
Figure 2. Overall test site
complete combustion. Exhaust gas from
the secondary combustion chamber then
is quenched by a water-fed venturi
scrubber emissions control system to
remove particulate matter and acid
gases. An induced draft fan transfers the
gas to the exhaust stack for discharge to
the atmosphere.
The same trailer housing the thermal
system also contains the control panel for
the main unit, and data collection
indicators and recorders. Safety
interlocks also are integrated into the
trailer-mounted unit to automatically
correct abnormal operating conditions,
maintain system performance, and if
necessary, shut down feed and heat input
to the unit.
Test Procedure
In order to meet the objectives of the
demonstration test (see Introduction), a
total of 17 test runs were conducted.
Three runs were performed under design
operating conditions to assess overal
unit operation and system performanct
(Phase \), and 14 runs were conductec
under varying operational parameters tc
evaluate their effect on systerr
performance and energy consumptior
(Phase II).
The Phase \ runs were conducted a
1600°F PCC temperature, a 2200°F SCC
temperature, and a PCC residence time
of 20 min. Each of the three runs wa;
sufficiently long (six to ten hours) tc
-------
gather a large enough sample of stack
gas to analyze it for PCBs. An additional
run was conducted at the same operating
conditions to obtain specific stack
samples that had not been successfully
collected during two of the previous runs.
The Phase II runs were conducted for
approximately one hour under varied
operating conditions that included the
PCC temperature (900, 1200, 1400, and
1600°F), SCC temperature (1800 and
2200°F), PCC feed residence time (10,
15, 20, and 25 minutes), and PCC
combustion air flow (on, off to simulate
oxidizing or non-oxidizing (pyrolytic) PCC
atmosphere).
For the Phase I runs, samples were
taken of the feed, scrubber makeup
water, furnace ash, scrubber water, and
scrubber solids. These streams were
analyzed for PCBs, dioxins and furans,
metals, organics, and other physical and
chemical properties and components
specific to the characterization of each
sampled matrix. In addition, the EP Tox
and TCLP leaching tests were performed
on these sampled streams (exclusive of
scrubber water makeup) and the extracts
were evaluated for metals. Samples were
also taken of the upwind and downwind
ambient air, PCC offgas, and stack gas.
Ambient air upwind and downwind of the
unit was monitored for PCBs and heavy
metals by high volume samplers. For the
stack gas and PCC offgas, several
sampling methods were employed,
including an EPA Method 5 for paniculate
matter (and subsequent metals analysis
of particulates) and hydrochloric acid; a
Source Assessment Sampling System
(SASS) for semivolatile organic
pollutants, PCBs, dioxins and furans; a
Volatile Organic Sampling Train (VOST)
for volatile organic pollutants; a Modified
Method 5 for soluble chromium;
continuous emission monitoring for
oxygen, carbon dioxide, carbon
monoxide, oxides of nitrogen, and total
hydrocarbons; and an experimental
method for vaporous lead emissions in
the PCC offgas.
For the Phase II runs, samples were
taken of the feed, furnace ash, scrubber
water, scrubber solids, PCC offgas, stack
gas, and upwind and downwind ambient
air. EPA Method 5 was used again to
sample stack gas and PCC offgas but
was analyzed only for particulate matter.
In addition, throughout the Phase II tests,
the stack gas and PCC offgas were
continuously monitored for oxygen,
carbon dioxide, carbon monoxide, oxides
of nitrogen, and total hydrocarbons. All of
the remaining sampled streams were
analyzed for PCBs, dioxins and furans,
metals, and other physical and chemical
properties and components specific to
the characterization of each sampled
matrix. In addition, the EP Tox and TCLP
leaching tests were performed on these
samples and the extracts were evaluated
for metals.
All of the sampling and analytical work
was conducted in accordance with
QA/QC Category II and include data
quality credibility statements for the
precision and accuracy of the data
reported.
Results and Discussion
A detailed summary of the SITE
demonstration test results is presented in
Table 1. Based on the test objectives
outlined in the Introduction, the following
results were obtained.
Characteristics of the Feed
Based on data from the previous
remedial investigation of the site, a
specific area within the site was
identified with the highest
concentrations of both PCBs and lead,
the major soil contaminants of concern.
The remedial investigation also
described the soil as a dry, brown,
sandy, and silty clay topsoil which
upon excavation proved to be an
accurate observation. Subsequent
pretest sampling and analysis of the
specific area of the site identified
particular sectors with the highest
contamination of PCBs and lead. A
composite sample of all the sectors
within the area indicated a 7.8 pH, 9.0
wt.% moisture, 81 wt.% ash, less than
1000 Btu/lb high heating value, and a
0.95 g/cc density. The composite
sample contained 570 ppm of total
PCBs and 580 ppm lead (elemental
lead after digestion and conversion to
inorganic form). A composite sample of
the 10 sectors chosen for excavation
contained 626 ppm PCBs, 560 ppm of
lead, 55 ppb of tetrachlorodibenzo-p-
dioxm (TCDD), and 4.2 ppb of
tetrachlorodibenzofuran (TCDF). Once
the feed excavation was begun, it
became evident that the front-end
loader could not confine its large-scale
activities to the 10 specific sectors and
an area comprising 14 specific sectors
was excavated for the unit's feed
source.
Table 1 summarizes the PCB and
lead contaminant concentrations
measured in the soil from the
composite of the grab samples of feed
taken during each of the test runs. In
addition to lead, where concentrations
ranged from 290 to 3000 ppm and
averaged 778 ppm, several other
metals were present at average
concentrations exceeding 50 ppm
including barium (591 ppm), zinc (301
ppm), and chromium (85 ppm). Total
PCBs concentration ranged from 10.2
to 669 ppm and averaged 272 ppm.
Several samples of the feed
contained small quantities of TCDFs
ranging from 0.04 to 0.1 ppb. Volatile
and semivolatile organic compounds
including methyl ethyl ketone,
trichloroethene, and bis(2-ethyl-
hexyl)phthalate were measured in feed
samples at concentrations less than 50
ppm. Methyl ethyl ketone and
trichloroethene were also detected in
solvent blanks and are attributed to
analytical laboratory contamination.
Characteristics of the Furnace Ash
Table 1 summarizes the PCB and
lead contaminant concentrations
measured in the furnace ash from the
composited grab samples taken at the
conclusion of each test run. In addition
to lead, where concentrations ranged
from 420 to 2000 ppm and averaged
1173 ppm, several other metals were
present at average concentrations
exceeding 50 ppm including barium
(1061 ppm), zinc (410 ppm), and
chromium (81 ppm). Total PCBs
concentration ranged from 0.004 to
3.396 ppm. Two samples of furnace
ash contained 0.07 and 0.3 ppb of
TCDF during two runs conducted at a
900°F PCC operating temperature; the
normal PCC operating temperature is
1600°F. These runs were also
conducted without the input of PCC
combustion air to simulate non-
oxidizing or pyrolytic combustion
conditions. The low PCC temperature
and pyrolytic environment could have
led to the incomplete desorption or
incineration of TCDF present in the
feed or to the production of TCDF from
the incomplete combustion of PCBs in
the feed. Volatile compounds including
methylene chloride, methyl ethyl
ketone, tetrachloroethene, and
trichloroethene were also measured in
the furnace ash samples in
concentrations ranging from 3.9 to 64
ppm with one sample containing 980
ppm of methylene chloride. Methyl
ethyl ketone and trichloroethene were
also detected in solvent blanks and
methylene chloride is commonly
employed in laboratory procedures;
therefore these compounds may be
-------
Table 1. Site Demonstration Test Results Summary
Operating Conditions
PCC
Temp.
"F
900a'b
900b
900b
1200
1200
7200<>
120Qb
1200»
7200*"
7400
7600
7600
7600
7600
7600
7600«
7600»
7600a«>
Residence
Time
min.
20
20
25
20
15
25
20
15
15
20
20
20
20
20
10
15
15C
15
PCB
ppm
327
20.2
367
297
27.6
456
669
602
309
56.0
10.2
35.2
20.4
t
391
451
271
311
Waste Feed
Characteristics
Pb
ppm
590
660
290
640
870
590
610
470
370
740
3000
1400
550
1100
620
620
390
500
EPTox
(Pb)
ppm
0.29
0.67
0.32
0.05
0.20
0.12
0.20
0.18
0.21
0.07
0.15
0.20
0.23
0.14
0.25
ND
0.53
0.07
3.009
TCLP
(Pb)
ppm
0.81
0.88
7.00
056
0.44
053
0.71
0.53
0.96
0.89
067
0.35
1.30
0.49
0.73
0.66
1.80
055
1.403
PCB
ppm
2079
3.396
0.168
0.115"
0.077
0.1081
0.066"
0.025"
0.066"
0.087"
0.037
0.772
0.003
I
0.045"
0.777"
0.004
0.067"
Furnace Ash
Characteristics
Pb
ppm
1,000
1,400
0.860
1,100
1,000
1,200
1.200
2,000
1,000
1,600
1,100
1,300
1,100
0.420
1,700
0.840
1,500
0.800
EPTox
(Pb)
ppm
0.38
0.89
0.88
4 10
0.38
0.14
0.06
4.909
h
046
ND
0.05
ND
0.13
028
ND
043
0.27
1.10
TCLP
(Pb)
ppm
2.90
620
3.80
1.60
3.60
005
4.10
2.809
h
0.82
0.15
ND
ND
0.05
1.80
1.00
0.17
0.23
2.40
* Waste feed blended with 3 wt.% fuel oil.
b Non-oxidizing atmosphere.
CPCC bed depth at 1 inch. All other tests at 7-7/2 inches.
dPCB levels below analytical detection limits. Total shown is sum of detectable limits indicated in analyses.
»ND - nondetectable value.
1 Run was conducted to make up for incomplete semivolatlle organics, PCDD/PCDF, soluble chromium and stack gas paniculate samplings on
other runs.
9 Data from additional EP Tox and TCLP tests.
hND due to broken sample container.
products of incomplete combustion
and/or the result of laboratory
contamination.
Residual PCBs in Furnace Ash
During the demonstration test, a total
of 17 runs were conducted at varying
operating conditions. In addition to the
ORE levels, which are an indication of
the performance of the Shirco Pilot-
Scale Infrared Incineration System and
its ability to meet RCRA and/or TSCA
regulatory standards, the reduction of
PCB concentration from the feed to the
furnace ash is also a measure of the
unit's ability to effectively destroy
PCBs and produce a furnace ash with a
PCB concentration below the TSCA
guidance level of 2 ppm.
Based on the data presented in
Table 1, two samples of furnace ash
exceeded the TSCA guidance levels
and contained 3.396 and 2 079 ppm of
total residual PCBs. The samples were
produced during two runs conducted at
a 900°F PCC operating temperature
(20 minutes residence time), which is
significantly lower than the normal PCC
operating temperature of 1600°F.
These runs were also conducted
without the input of PCC combustion
air to simulate non-oxidizing or
pyrolytic combustion conditions. At this
low PCC temperature and pyrolytic
condition, these higher total residual
PCB levels in the furnace ash may be
the result of the incomplete combustion
of PCBs in the feed. This is further
substantiated by the residual TCDF
present in the furnace ash samples
from these same two runs, as
discussed previously. The remaining
runs conducted at 1200, 1400, ani
1600°F resulted in total residual PCI
concentrations in the furnace as
ranging from 0.003 to 0.117 ppm. i
third run, which was conducted at
900°F PCC operating temperature bi
with an increased PCC residence tim
of 25 minutes resulted in a total furnac
ash PCB concentration of 0.168 ppr
with no detectable TCDF. It is possibl
that the increased residence time in th
PCC may have offset the low 900°
PCC operating temperature an
provided the additional processing tim
for the satisfactory destruction of th
PCBs in the feed.
Mobility of Heavy Metals - Feed an
Furnace Ash
In order to determine whether heav
metals, particularly lead, would leac
-------
from the furnace ash produced in the
Shirco Pilot-Scale Infrared Incineration
System, EP Tox and TCLP tests were
conducted to determine the mobility of
heavy metals from the furnace ash as
compared to the feed.
The initial EP Tox analyses for lead
in the leachate ranged from 0.05 to
0.67 ppm for the feed and 0.05 to 4.1
ppm for the furnace ash. The initial
TCLP analyses ranged from 0.35 to
1.80 ppm (with one sample at 7.0 ppm)
for the feed and 0.05 to 4.1 ppm (with
one sample at 6.2 ppm) for the furnace
ash.
A comparison of the EP Tox and
TCLP analyses conducted on the
furnace ash and the feed do not show
any trend or evidence that indicate
reduced mobility of lead from the
furnace ash versus the feed as a result
of the thermal treatment. The
comparison did reveal that the
concentrations of lead in the TCLP
leachates from both the feed and the
furnace ash were consistently higher
than the corresponding EP Tox tests
on the same samples.
When several samples were retested
to verify the results, the concentrations
of lead in the EP Tox leachates (4.9
ppm feed, 3.0 ppm furnace ash) were
higher than during the initial tests and,
in direct reversal to the original data,
exceeding corresponding TCLP
leachate concentrations (2.8 ppm feed,
1.4 ppm furnace ash). The results of
the retest again did not indicate
reduced mobility of lead from the
furnace ash versus the feed as a result
of the thermal treatment.
Mobility of Heavy Metals - EP Tox and
Proposed TCLP Toxicity Characteristic
Standards
EP Tox and TCLP tests were con-
ducted on the feed, furnace ash,
scrubber water, and scrubber solids. All
of the results were below the EP Tox
and proposed TCLP toxicity
characteristic standards of 5 ppm
arsenic, 100 ppm barium, 1 ppm
cadmium, 5 ppm chromium, 5 ppm
lead, 0.2 ppm mercury, 1 ppm
selenium, and 5 ppm silver except for
one feed sample at 7.0 ppm lead
(TCLP ) and one furnace ash sample at
6.2 ppm lead (TCLP). A comparison of
the EP Tox and TCLP analyses on all
the sampled streams to the above
mentioned standards do not show any
trend or evidence that indicate reduced
mobility of heavy metals as a result of
the thermal treatment.
Destruction and Removal Efficiency
(ORE) of PCBs
The ORE of PCBs for the first three
runs (Phase I) is greater than 99.99%.
In contrast, the regulatory standard for
incineration under the RCRA is 99.99%
ORE and under TSCA is 99.9999%
ORE. The low PCB concentrations in
the feed resulted in PCB levels in the
stack gas that were less than the
analytical detection limits for two of the
runs. Therefore for these runs, ORE is
calculated based on the sum of the
detection limits of the PCB congeners
in order to compare the ORE for the
runs on the same basis. Stack gas
measurements conducted during the
third run did detect trichlorobiphenyl
and tetrachlorobiphenyl congeners and
a ORE is shown based on this
measurement. The less rigorous
sampling in Phase II of the test was not
designed to allow calculation of ORE.
Other Organic Stack Gas and PCC
Offgas Emissions
Several volatile and semivolatile
organic compounds were detected in
the stack gas at concentrations less
than 100 ppb and established
standards for direct inhalation. Low
levels of several phthalate compounds
were also detected in blank samples
and may be traced to contamination
from plastic components in the
process, sampling equipment, or
laboratory apparatus. Several volatile
organic compounds including benzene
and toluene were detected in the stack
gas and the scrubber makeup water
and may be attributable to
contamination from the makeup water
although PIC formation is a possibility.
Other volatile and semivolatile organic
compounds, which probably represent
PICs, were detected. They include
halomethanes, chlorinated species
including chlorobenzene and
methylene chloride, other volatile
organics including xylenes, styrene and
ethylbenzene, oxygenated hydro-
carbons including acetone and
acrolem, carbon disulfide, and p-chlor-
m-cresol. Dioxins and furans were not
detected in the stack gas samples.
The majority of the organic
compounds present in the PCC off gas
samples at levels less than 500 ppb
were also present in the stack gas. The
additional destruction of organics that
take place in the SCC and emissions
scrubbing system reduced the
concentration of these organic
compounds in the corresponding stack
gas samples.
Acid Gas Removal
During the Phase I Runs 1-3, HCI
emissions ranged from 0.181 to 0.998
g/hr, which were significantly below the
RCRA performance standard of 1800
g/hr that would require a 99 wt.% HCI
removal efficiency. HCI removal
efficiencies ranged from 97.23 to 99.35
wt.%. Acid gas removal was not
measured in Phase II.
Particulate Emissions
Particulate emissions were measured
throughout the test and ranged from 7
to 68 mg/dscm, well below the RCRA
standard of 180 mg/dscm.
Analysis of Scrubber Makeup Water,
Scrubber Water, and Scrubber Solids
Scrubber makeup water was
transported to the site in a tank truck that
may have contained some residual
contamination prior to fill up. Samples of
scrubber makeup water were taken at the
end of each run. No PCBs, dioxins,
furans, or semivolatile organic
compounds were detected. Several
volatile organics including benzene,
toluene, and trichloroethene were
measured at concentrations less than 15
ppm. The concentrations of heavy metals
were all less than 0.2 ppm.
Samples of the water recirculation
through the venturi scrubber system,
referred to as scrubber water, were also
taken at the end of each run. PCB
concentrations were less than 200 ppt
and no dioxins, furans, or semivolatile
organic compounds were detected. Small
quantities of benzene (2 ppm) and
toluene (5.7 to 11 ppm) were measured
in several of the samples and are
attributable to the similar contaminants in
the scrubber makeup water. The
concentrations of heavy metals in the
scrubber water were all less than 1 ppm
except for barium, which ranged from 0.2
to 2.2 ppm, and lead, which ranged from
0.12 to 1.8 ppm.
Insufficient quantities of scrubber solids
in the scrubber water were available for
analysis.
Overall Disposition of Metals
Total metals analyses of the feed,
furnace ash, PCC offgas and stack gas
particulates, scrubber makeup water,
scrubber water, and scrubber solids
showed that the majority of the
detectable metals, including lead, that
-------
entered the unit with the feed remained
in the furnace ash. An overall mass
balance of lead through the unit was
calculated based on the analysis of
lead in the samples, the measured feed
rate as weighed during the runs'
operating periods, the calculated
furnace ash flow rate based on the
ultimate analysis of ash in the feed
sample, and the measured particle
mass and gas volume obtained from
the gas' EPA Method 5 sampling trains.
Phase I results indicate an average
lead mass flow rate of 28.3 g/hr in the
feed, 37.0 g/hr in the furnace ash,
0.206 g/hr in the PCC offgas
particulates, and 0.109 g/hr in the stack
gas particulates. The quantity of lead
leaving the unit with scrubber water
effluent is approximately 0.204 g/hr
based on the maximum measured
concentration of 1.8 ppm lead in the
scrubber water and an overall
approximate water flow rate of 30 gph.
The PCC offgas particulates sampled
during the Phase I runs contained an
average of 5364 ppm of lead as
compared to stack gas particulates,
which contained an average of 15,830
ppm of lead. By contrast, the average
concentration of lead in the feed was
1550 ppm. Although the concentration
of lead in the particulate matter
increases as the process flow
progresses through the unit, the actual
mass flow of lead decreases as the gas
stream is cooled and treated through
the emissions control system.
For the Phase I runs sampling and
analysis procedures were conducted to
evaluate vaporous lead concentrations
in the PCC offgas and soluble
chromium concentrations in the PCC
offgas and stack gas particulates. The
special sampling for vapor phase lead
and soluble chromium were unable to
detect any of either metal at levels less
than 2.7 ppb and 264 ppb,
respectively; therefore the evaluations
were inconclusive.
Other heavy metals, particularly
barium and zinc, with average
concentrations exceeding 100 ppm in
the feed (barium 591 ppm, zinc 301
ppm) were also present in high
concentrations, relative to other heavy
metals, in the furnace ash (barium 1061
ppm, zinc 410 ppm) and scrubber
water (barium 0.8 ppm, zinc 0.3 ppm).
Optimum Operating Conditions
Phase II was designed to examine
the effect on energy consumption and
changes in the residual levels of heavy
metals and organics in the furnace ash
versus the levels in the feed by varying
operating conditions.
Based on the data obtained an
analysis was conducted to compare
energy consumption in the unit at
operating conditions that did not affect
the performance of the unit. A
reduction in the PCC operating
temperature from 1600°F to 1200°F
reduced the average PCC power usage
48% from 0.2294 to 0.1200 kwhr/lb
feed. A reduction in the SCC operating
temperature from 2200°F to 1800°F
reduced the average propane fuel
consumption by 51% from 3997 to
1952 Btu/lb feed. The use of 3 wt.%
fuel oil to supplement the fuel value of
the feed further decreased PCC power
usage by 26 to 67% at PCC operating
temperatures of 1600°F and 1200°F,
respectively, with accompanying
increases in overall feed rate of 32%
and 26%. The costs for fuel oil and its
attendant facilities still must be
examined for specific applications to
determine the cost effectiveness of a
fuel oil additive to the waste feed.
As discussed in previous sections
the results did not provide any trend or
change in the residual levels of the
heavy metals and organics in the
furnace ash versus the levels in the
feed as the operating conditions were
varied and PCC operating temper-
atures were maintained at 1200°F to
1600°F. At an abnormally low PCC
operating temperature of 900°F,
without the input of combustion air to
simulate non-oxidizing or pyrolytic
combustion conditions, total PCB and
TCDF concentrations in the furnace
ash increased. The increases may
indicate that these PCC conditions led
to incomplete desorption or incineration
of PCB and TCDF and to the
production of TCDF from the
incomplete combustion of PCBs in the
feed.
QA Summary
The Phase I and II runs had a well-
defined quality assurance/quality
control program to ensure the
collection of accurate data. This
program was developed as part of the
test program preparation activities and
was formalized in the RREL approved
QA Project Plan (Category II). All of the
sampling and analytical work was
conducted in accordance with this QA
Project Plan and the results include
data quality credibility statements and
information that confirm the satisfactory
precision and accuracy of the date
reported.
Conclusions
Based on the above data anc
discussion, the following conclusions car
be made concerning the operation anc
performance of the Shirco Pilot-Scale
Infrared Incineration System.
I.The PCC equipped with infrarec
heating rods reduced PCBs from ar
average of 272 ppm and a maximurr
of 669 ppm in the feed to less thar
0.2 ppm PCBs in the furnace asr
when PCC temperature was 1200°F
or higher. PCB levels in the ash were
well below the TSCA guidance leve
of 2 ppm of PCBs in treatmen
residuals.
2. The majority of the lead and othei
heavy metals present in the feec
remained in the furnace ash
regardless of operating conditions
However, the scrubber wate
contained levels of lead and bariurr
(up to 1.8 to 2.2 ppm, respectively)
and metals also concentrated tc
some extent in the furnace ash. Bott
residual streams may require furthe
treatment when metals are present ir
the feed.
3. In most cases concentrations o
metals in the extract of the furnace
ash did not exceed their respective
EP Tox and TCLP toxicity charac
teristic standards. The need fo
further treatment of the furnace ast
to reduce or immobilize the metals i:
site specific, and will depend on the
cleanup standards for the site.
4. Based on two leaching tests, the EF
Tox and TCLP, the mobility of leac
and other heavy metals was simila
in the feed and the furnace ash, anc
there was no evidence that treatmen
affected metals leaching.
5. The unit achieved DREs of PCB;
greater than 99.99%, based on one
actual calculation and in two case;
on detection limits. PCB concen
trations in the feed and analytica
detection limits did not allow th<
demonstration of 99.9999% ORE
required under TSCA. However, thi:
unit achieved greater than 99.99990/
ORE in other tests, and at this tim<
at least one full-scale infrared system
has demonstrated greater thai
99.9999% ORE for PCBs and i:
permitted under TSCA to proces;
PCB waste. The upcoming Appli
-------
cations Analysis Report
incorporate this additional data.
will
6.The unit achieved regulatory
standards for acid gas removal and
particulate emissions. These data
apply to the operation and per-
formance of the air pollution control
system installed on this unit.
Additional data on the performance
of air pollution control systems on
full-scale Shirco Infrared units will be
discussed in the Applications Anal-
ysis Report.
7. Several semivolatile and volatile
organic compounds measured in the
stack gas in the parts per billion may
be PICs. These levels are much
lower than established standards for
direct inhalation of these compounds.
8. The unit was able to reduce the
PCBs in the feed using less power
when fuel oil was added to the waste
and when PCC temperature was
reduced. The addition of fuel oil also
increased the feed rate. Cost savings
in specific applications will depend
on local fuel and electrical costs, and
a minimum PCC temperature must
be maintained to avoid inadequate
desorption of the organics in the feed
and the production of PICs.
------- |