United States
Environmental Protection
Agency
Office of
Research and Development
Cincinnati, Ohio 45268
E PA SITE Technology Capsule
Sonotech Pulse
Combustion System
EPA/540/R-95/502a
August 1995
Introduction
In 1980, the U.S. Congress passed the Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA), also known as Superfund, which is committed
to protecting human health and the environment from
uncontrolled hazardous waste sites. CERCLA was
amended by the Superfund Amendments and
Reauthorization Act (SARA) in 1986. SARA mandates
cleaning up hazardous waste sites by implementing
permanent solutions and using alternative treatment
technologies or resource recovery technologies to the
maximum extent possible.
State and federal agencies and private organizations are
exploring a growing number of innovative technologies for
treating hazardous wastes. These new innovative
technologies are needed to remediate the more than
1,200 sites on the National Priorities List, which involve a
broad spectrum of physical, chemical, and environmental
conditions requiring diverse remedial approaches
The U.S. Environmental Protection Agency (EPA) has
focused on policy, technical, and informational issues
related to exploring and applying new technologies to
Superfund site remediation. One EPA initiative to
accelerate the development, demonstration, and use of
innovative technologies for site remediation is the
Superfund Innovative Technology Evaluation (SITE)
program.
EPA SITE Technology Capsules summarize the latest
information available on selected innovative treatment and
site remediation technologies. The Technology Capsules
assist EPA remedial project managers, EPA on-scene
coordinators, contractors, and other remedial managers
in the evaluation of site-specific chemical and physical
characteristics to determine a technology's applicability
for site remediation.
This Technology Capsule provides information on the
Sonotech Pulse Combustion System, which includes the
patented Cello® pulse burner, developed by Sonotech, Inc.
(Sonotech), of Atlanta, Georgia. Sonotech claims that
its combustion system can be beneficial in a variety of
combustion processes. The system incorporates a
combustor that can be tuned to induce large amplitude
sonic pulsations inside combustion process units, such
as boilers or incinerators. According to Sonotech, these
pulsations increase heat release, mixing, and mass
transfer rates in the combustion process, resulting in faster
and more complete combustion. Sonotech has targeted
waste incineration as a potential application for the system.
To test its potential applicability and effectiveness on a
Superfund waste, the Sonotech pulse combustion system
was demonstrated on a pilot-scale rotary kiln incineration
system (RKS) at the EPA Incineration Research Facility
(IRF) in Jefferson, Arkansas. In the demonstration, a
Sonotech pulse combustion system was retrofit to the
primary combustion chamber of the RKS.
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Printed on Recycled Paper
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This Technology Capsule presents the following
technology information:
• Abstract
• Technology description
Technology applicability
Technology limitations
• Process residuals
• Site requirements
• Performance data
Technology status
Sources of further information
Abstract
Sonotech has targeted waste incineration as a potential
application for this technology. Based on bench-scale
rotary-kiln simulator tests, Sonotech proposed a
demonstration under the SITE program to evaluate the
Sonotech pulse combustion system on a larger scale at
EPA's IRF in Jefferson, Arkansas.
The primary objective of the SITE program demonstration
was to develop test data to evaluate the Sonotech pulse
combustion system's treatment efficiency compared to
conventional combustion. Test data were evaluated to
determine if the Sonotech pulse combustion
system (1) increased incinerator capacity, (2) increased
destruction and removal efficiency (ORE) of principal
organic hazardous constituents (POHC), (3) decreased
flue gas carbon monoxide emissions, (4) decreased flue
gas nitrogen oxides emissions, (5) decreased flue gas
soot emissions, (6) decreased combustion air
requirements, and (7) decreased auxiliary fuel
requirements.
The secondary objective of the demonstration was to
develop additional data to evaluate whether the Sonotejch
system, compared to conventional combustion,
(1) reduced the magnitude of transient puffs of carbon
monoxide and total unburned hydrocarbons
(TUHC); (2) significantly changed the distribution of
hazardous constituent trace metals among the incineration
system discharge streams (including kiln bottom ash,
scrubber liquor, and baghouse exit flue gas), (3) changed
the teachability of the toxicity characteristic leaching
procedure (TCLP) trace metals from kiln ash, (4) reduced
the incineration costs, and (5) was reliable.
To achieve the demonstration objectives, tests were
performed in triplicate at four different incineration system
operating conditions, for a total of 12 individual tests. The
four test conditions included (1) conventional combustion
at typical operating conditions and feedrate;
(2) conventional combustion at its maximum feedrate;
(3) Sonotech pulse combustion at the conventional
combustion maximum feedrate, the same nominal feedrate
as condition (2); and (4) Sonotech pulse combustion at
its maximum feedrate.
The Sonotech pulse combustion system increased the
incinerator waste feedrate capacity by 13 to 21 percent
compared to conventional combustion. In addition, visual
observations indicated improved mixing in the incinerator
cavity with the Sonotech system operating.
The SITE program demonstration also revealed that,
compared to conventional combustion, the Sonotech pulse
combustion system reduced combustion air requirements
as well as overall emissions of carbon monoxide, nitrogen
oxides, and soot. Many of the data regarding the reduced
emissions were within the precision of the measurement
methods.
Technology Description
A pulse combustor typically consists of (1) an air and fuel
inlet section including pressure-controlled flapper valves,
(2) a combustion section, and (3) an exhaust section
(see Figure 1). The entire unit can be added to an existing
combustion process unit such as an incinerator. For this
demonstration, the pulse combustor exhaust pipe was
inserted into the rotary kiln combustion chamber of the
incinerator.
The operation of pulse combustion is controlled by a
complex interaction between an oscillating combustion
process and acoustic waves that are excited inside the
combustor. In the Sonotech pulse combustion system,
fuel oxidation and heat release rates vary periodically with
time, producing periodic variations or pulsations in
pressure, temperature, and gas velocity. The pulse
combustor sustains a cyclic combustion process by
modulating the inflow of reactants (air and fuel) into the
combustion section. Figure 1 depicts the phases of a
single pulse of a pulse combustor. Sonotech claims that
large amplitude resonant pulsations excited by its tunable
pulse combustor can significantly improve an incinerator's
performance, thereby reducing capital investment and
operating costs for a wide variety of incineration systems.
With the pulse burner combustion section at atmospheric
pressure, operation is initiated by sequentially introducing
air and fuel. Initially, the mixture is ignited by a spark
plug inside the combustor, producing a rapid pressure rise
that closes the flapper valves and initiates a flow of gases
into the exhaust pipe. The outflow of gases through the
exhaust pipe decreases the pressure in the combustion
chamber.
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AIR FLAPPER VALVE
FUEL
FLAPPER VALVE -
INLET :
SECTION :
EXHAUST PIPE
- - COMBUSTION AND
EXPANSION OF GASES
COMBUSTION
SECTION
EXHAUST
SECTION
FLAPPERS OPEN
AND ADMIT r-LUAi'
REACT ANTS pO i\"
EMPTYING PHASE
I OF THE COMBUSTOR
COMBUSTION
atmospheric
Figure 1: Operation of a Pulse Combustion System
When the combustion-produced pressure rise becomes
less than the outflow-produced pressure decrease,
combustor pressure begins to decrease. When the
combustor pressure reaches its minimum value, the flow
of gases in the exhaust pipe reverses direction and gases
in the exhaust pipe re-enter the combustor.
As the combustor pressure drops, the valves open and
admit new charges of fuel and air. These mix rapidly and
ignite as they come into contact with pockets of burning
gases left over from the initial cycle. Ignition is followed
by combustion and a pressure rise similar to that in the
initial cycle. The initial cycle is completed at the instant
when the increasing pressure equals the atmospheric
pressure. This periodic (pulsed) combustion process
continues indefinitely without the need of the spark plug.
To excite large amplitude pulsations inside an incinerator,
the pulse combustor must operate at a frequency that
equals one of the natural acoustic modes of the incinerator.
When this condition is satisfied, the incinerator is in
resonance. Creation of large amplitude pulsations is
achieved by (1) retrofitting a frequency-tunable pulse
combustor through a wall of the incinerator and (2) varying
its frequency until one of the natural acoustic modes of
the incinerator is excited. The desired resonant operating
condition is established by using one or more pressure
transducers to monitor changes in the amplitude of
pulsations inside the incinerator in response to changing
the pulse combustor frequency. The desired operating
condition is reached when the transducers indicate that
the amplitude of pulsations inside the incinerator has been
maximized.
Typically, pulse combustors can oscillate with frequencies
that vary from 20 to several hundred cycles per second.
These oscillations cause acoustic waves to form inside
the combustor as its pressure increases above and
decreases below atmospheric pressure.
Pulse combustion can be applied to a range of combustion
processes such as boilers, dryers, calciners, and
incinerators. In such applications, the pulse combustor
can be used as the process burner, supplying all of the
heat input to the process, or it can be a secondary burner
that is used to excite pulsations in the combustion
process. When used as a secondary burner, the pulse
combustor delivers only a fraction of the main combustion
process heat input (as little as 2 percent), while still
exciting resonant pulsations in the process combustor.
The remaining heat input is supplied by the conventional
burner and other process feed streams.
For the SITE demonstration, a Sonotech pulse combustion
system was used as the pulse generator for the RKS.
Figure 2 presents a process schematic of the Sonotech
pulse combustion system installed on the RKS. The RKS
consists of a rotary kiln primary combustion chamber, a
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NATURAL GAS
TRANSFER DUCT
SONOTECH ^^
PULSE BURNER
AIR 1
NATURAL GAS
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TOA1RFH
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ASH
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AFTERBURNER
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ROTARY
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Figure 2: The Sonotech Pulse Combustion System Fitted to the IRF RKS
transition section, a fired afterburner chamber, and a
quench section followed by the primary air pollution control
system (ARCS). The primary ARCS for the SITE
demonstration consisted of the venturi scrubber followed
by a packed-column scrubber and fabric-filter baghouse.
The scrubber system removes most of the coarse
particulate and any acid gas, such as hydrochloric acid in
the flue gas. Following the scrubber system, the flue gas
is reheated to about 250 °F by a 100-kilowatt (kW) electric
duct heater, then passes through the fabric filter baghouse.
The baghouse removes most of the remaining flue gas
particulate. Reheating the flue gas ensures that no
moisture will condense in the baghouse and adversely
affect its operation.
To assure permit compliance, a secondary, or redundant,
ARCS consists of a demister, an activated-carbon adsorber,
and a high-efficiency particulate air filter. The backup
ARCS is designed to ensure that organic compound and
particulate emissions to the atmosphere are negligible.
The following sections discuss the main components of
the RKS and its ARCS.
RKS Characteristics
The rotary kiln combustion chamber has an inside diameter
of 3.4 feet and is 7.4 feet long. The chamber is lined with
refractory to an average thickness of 7.4 inches; the
refractory is then encased in a 0.375-inch-1hick steel shell.
Total volume of the rotary kiln chamber, including the
transfer duct, is 67.2 cubic feet. Four steel rollers support
the rotary kiln barrel, which is turned by a variable-speed
direct current motor coupled to a reducing-gear
transmission. Rotation speed can be varied from 0.2 to
1.5 revolutions per minute.
The afterburner chamber is 3 feet in diameter and 10 feet
long. The afterburner chamber wall is constructed of
a 6-inch-thick layer of refractory encased in a
0.25-inch-thick carbon-steel shell. The volume of the
afterburner chamber is 41.9 cubic feet.
Both the rotary kiln and afterburner are equipped with
2-million British thermal units per hour (Btu/hr) auxiliary
fuel burners. Natural gas is used as the auxiliary fuel,
although liquid waste or other fuels can also be fired.
Typical firing rates can range from 1 - to 1.5-million Btu/hr
to the rotary kiln and 1.5- to 2-million Btu/hr to the
afterburner.
For the SITE demonstration, Sonotech engineers retrofit
the RKS with a pulse combustion system with a capacity
of 0.25-million Btu/hr or roughly 15 to 20 percent of the
typical heat input to the rotary kiln. The retrofit system
consisted of a frequency-tunable pulse combustor,
associated fuel and air flow controls, a process control
system, and appropriate structural support. The tunable
pulse combustor was mounted into the stationary wall at
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the ash pit end of the rotary kiln chamber. Operation of
the afterburner was controlled independently of the rotary
kiln by a separate process control loop. Fuel (consisting
of natural gas) and air supply were taken from existing
facility supply lines. Appropriate safety interlocks between
the Sonotech system and the RKS system were also
designed and installed.
Technology Applicability
The Sonotech pulse combustion system was evaluated
to determine the advantages, disadvantages, and
limitations of the technology. The evaluation was based
on the nine criteria used for decision-making in the
Superfund feasibility study process. Results are
summarized in Table 1.
For the SITE demonstration, the waste feed for all test
runs consisted of a composite mixture of contaminated
soil, sludge, and tar from two abandoned manufactured
gas plant (MGP) Superfund sites, one a coal-MGP, and
the other an oil-MGP. One component of the waste feed
consisted of a combination of pulverized coal and
contaminated coal-tar sludge from the Peoples Natural
Gas Company Superfund site in Dubuque, Iowa. The other
components of the waste feed material were obtained from
an MGP site in the southeastern United States; these
components consisted of contaminated soil borings and
tar waste from an oil gasification process. The mixed
waste feed had a nominal heating value of 8,500 British
thermal units per pound of waste (Btu/lb).
Materials-handling requirements and site-support
requirements are identical to those of the incinerator
operating without the Sonotech system in place.
For the SITE demonstration, the technology was
evaluated on its ability to destroy volatile and semivolatile
organic compounds. Sonotech claims its system can also
be applied to the incineration of pesticides, polychlorinated
biphenyls, and dioxins and furans. In addition, Sonotech
claims that the technology can be applied to processes
such as drying, calcining, and heating.
The Sonotech combustor can be incorporated into the
construction of most new combustion devices or can be
retrofit to many existing systems ranging in thermal
capacity from 250,000 Btu/hr to 200 million Btu/hr. The
Sonotech pulse combustion system can be used to treat
any material typically treated in a conventional incinerator,
and Sonotech believes the technology is ready to be used
for the full-scale incineration of hazardous, municipal, or
medical wastes. For most applications, the Sonotech
system can be transported in a medium-duty truck.
Technology Limitations
The Sonotech pulse combustion system can be used to
treat any material typically treated in a conventional
incinerator with few limitations. The system typically
operates at one of the several resonant frequencies in the
range of 100 to 500 cycles per second (Hertz). The system
relies on this frequency to excite large amplitude pulsations
in the incineration chamber. While it is possible that
improper application of sound pulsations may present
structural problems, Sonotech claims that its system is
designed to avoid such problems. Inside the pulse
combustor, the sound pressure does not exceed 1 pound
per square inch or 168 decibels (dB). No structural damage
to the RKS was observed during the demonstration.
Outside the burner system, noise is typically in the
95- to 100-dB range. In the typical work environment of
an incinerator, the noise may be sufficiently loud to be of
concern. Sonotech can enclose the system to reduce
the noise intensity, or the entire incinerator can be remotely
located or enclosed to reduce the noise. In most
applications, Sonotech believes that the loud noise will
be a minor concern.
Process Residuals
An incinerator configured with the Sonotech pulse
combustion system will generate the same types of
residuals as an incinerator without the system, primarily
incinerator ash and stack gases. Treatment residuals of
kiln ash, baghouse ash, and scrubber liquor will require
proper treatment and disposal. In addition, the
demonstration results indicate that the heating value of
the incinerator ash was reduced when the Sonotech system
was used.
Site Requirements
Site requirements for an incinerator equipped with the
Sonotech pulse combustion system would be nearly
identical to those of an incinerator without the system.
The Sonotech system requires an additional area of about
4 feet by 10 feet on one side of the incinerator, where the
system can be mounted. A port into the combustion
chamber is also needed to place the internal portion of
the Sonotech burner. The Sonotech system requires an
additional air and natural gas line, but it requires only a
nominal amount of additional electricity. Depending on
the application and location, sound control may be
necessary when the Sonotech system is used; this sound
control may consist of insulation around the unit, isolation
of the incinerator, or possibly use of a sound-suppression
system.
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Table 1: Feasibility Study Evaluation Criteria for the Sonotech Technology
CRITERION
1 Overall Protection of
Human Health and the
Environment
2 Compliance with Federal ARARs
3 Long-Term Effectiveness
and Performance
4 Reduction of Toxicity,
Mobility, or Volume
Through Treatment
5 Short-Term Effectiveness
6 Implementability
7 Cost
8 State Acceptance
9 Community Acceptance
SONOTECH TECHNOLOGY PERFORMANCE
The pulse combustion system technology, used with a
conventional combustion chamber, destroys organic
hazardous constituents in the waste feed. Air emissions are
reduced by using an air pollution control system (APCS).
Compliance with chemical-, location- and action-specific
applicable or relevant and appropriate requirements (ARARs)
must be determined on a site-specific basis. Compliance with
chemical-specific ARARs depends on the treatment efficiency
of the combustion system and the chemical constituents of the
waste.
Contaminants are permanently removed from the waste.
Treatment residuals from the APCS and the kiln ash require
proper off-site treatment and disposal.
With incineration, both the toxicity and volume of the waste are
reduced with the destruction of organic components of the
waste. With the Sonotech system, the distribution and TCLP
teachability of metals were unaffected in the kiln ash, but
barium and chromium concentrations were slightly lower in the
scrubber liquor and higher in the baghouse exit flue gas.
The Sonotech system reduces the time requirement for
treatment by increasing the feedrate of a conventional
combustion system. Short-term risks to workers, the
community, and the environment are presented during waste
handling activities and from potential exposures to flue gas
emissions Adverse impacts from both can be mitigated with
proper controls and procedures. Short-term risks should be
similar to those from conventional combustion.
The Sonotech system can be easily incorporated into new
incinerator systems and can be retrofit to most existing
incinerators. In addition, the system can be used to treat any
material typically treated in a conventional incinerator.
Capital costs for equipment and installation are estimated to
be in the range of $65,000 to $75,000, and annual operation
and maintenance costs are estimated to be $2,500 for a
full-scale incinerator.
State acceptance is anticipated to be favorable because the
system can be used as a retrofit to an existing permitted
hazardous waste incinerator to improve the performance of
conventional combustion technology.
The minimal short-term risks presented to the community
along with the permanent removal of hazardous waste
constituents and the improved performance of a permitted
waste combustion unit should make public acceptance of this
technology more probable.
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Materials-handling requirements for an incinerator are not
affected by the Sonotech pulse combustion system;
however, the Sonotech system may require an increased
feedrate to the incinerator.
Performance Data
To achieve the demonstration objectives, tests were
performed in triplicate at four different incineration system
operating conditions, for a total of 12 individual tests. The
four test conditions included (1) conventional combustion
at typical operating conditions; (2) conventional
combustion at its maximum feedrate, which approaches
permit noncompliance; (3) Sonotech pulse combustion at
the conventional combustion maximum feedrate (the same
nominal feedrate as condition 2); and (4) Sonotech pulse
combustion at its maximum feedrate. A summary of the
operating data and results is presented in Table 2. As
shown in this table, the kiln exit gas temperature was
approximately 1,700 °F while the aifterburner exit gas
temperature was 2,000 °F. The results of preliminary
testing with the Sonotech system operating showed that
the rotary kiln gas temperature had to be limited to 1,700 °F
to prevent slag formation, while the afterburner could be
maintained at a typical operating temperature of 2,000 °F.
Results of the test program in terms of the primary
objectives are summarized below.
Incinerator Capacity
The Sonotech pulse combustion system increased the
incinerator waste feedrate capacity by 13 to 21 percent
compared to conventional combustion. As the
demonstration waste had significant heat content, the
capacity increase was equivalent to a reduction in the
auxiliary fuel needed to treat a unit mass of waste from
27,400 Btu/lb for conventional combustion to
21,500 Btu/lb for the Sonotech system. Visual
observations indicated improved mixing in the incinerator
cavity with the Sonotech system operating.
Destruction and Removal Efficiency
ORE is the measure of organic constituent destruction
and removal during the test program; POHCs for this
demonstration included benzene and naphthalene. The
POHC DREs were calculated from the concentrations of
benzene and naphthalene in the flue gas emissions and
their respective feedrates, as follows.
ORE = (1 -
emission rate
feedrate
) x 100
Benzene DREs for all 12 test runs were greater than
99.994 percent, with a slight improvement in the third
decimal place for the Sonotech combustor results. With
the Sonotech pulse combustion system operating, the
average benzene emission rate was reduced from 7.7 to
5.7 milligrams per hour (mg/hr) at the afterburner exit.
This represents a 26 percent reduction. The quantitation
of benzene at these low emission rates is within the
precision of this type of measurement.
Naphthalene DREs were greater than or equal to
99.998 percent for all test runs. With the Sonotech pulse
combustion system operating, the average naphthalene
emission rate was reduced from 1.2 to 1.1 mg/hr at the
afterburner exit. This represents an 8 percent reduction,
although again, the quantitation of naphthalene at these
low emission rates is within the precision of this type of
measurement.
For every test, concentrations of all organic constituents
were below their respective analytical method detection
limits in the kiln bottom ash, indicating that the waste
feed was essentially decontaminated of organics for all
12 test runs.
Carbon Monoxide and Nitrogen Oxides
Emissions
The average afterburner exit carbon monoxide
concentration, corrected to 7 percent oxygen, decreased
from 20 parts per million (ppm) with conventional
combustion to 14 ppm with the Sonotech system. This
represents a 30 percent reduction.
The average afterburner exit nitrogen oxides concentration,
corrected to 7 percent oxygen, decreased from 82 ppm
with conventional combustion to 77 ppm with the Sonotech
system. This represents a 6 percent reduction.
Soot Emissions
Flue gas soot was measured by analyzing the carbon
content of the afterburner exit flue gas particulates.
Average afterburner exit soot emissions, corrected to
7 percent oxygen, were reduced from 1.9 milligrams per
dry standard cubic meter (mg/dscm) for conventional
combustion to less than 1.0 mg/dscm with the Sonotech
system. This represents a 47 percent or greater decrease
in soot. However, all soot measurements were within a
factor of 3 of the method detection limit, so the significance
of this reduction is uncertain.
Combustion Air Requirements
One of Sonotech's claims about the technology was that
pulsations would induce better gas phase mixing, resulting
in more efficient combustion and reduced combustion air
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Table 2: Operating Data and Results
1 : Conventional
Parameter Combustion
Baseline
Feed- ate
Waste teedrate, Ib/hr
Rotary kiln exit gas temperature, ' F
Afterburner exit gas temperature "F
Heat input, kBtu/hr
Waste feed
Kiln auxiliary fuel
Main burner
Sonotech burner
Total kiln
Afterburner auxiliary fuel
Total auxiliary fuel
Total system heat input
Kiln ash heating value, Btu/lb
Combustion air, dscf/hr
Afterburner exit CO, ppm at 7% O2
Afterburner exit NOx, ppm at 7% O2
61.0
1,720
2,000
522
656
0
656
1,010
1 ,670
2,190
1 ,240
41,700
15
90
2: Conventional
Combustion
Maximum
Feedrate
72.8
1,730
2,000
601
516
0
516
1,020
1,540
2,140
1,320
39,500
20
82
3: Pulse
Combustion
Baseline
Feedrate
73.6
1,700
2,000
628
487
200
687
894
1,580
2,210
<500
35,700
14
77
4: Pulse
Combustion
Maximum
Feedrate
82.4
1,700
2,000
697
403
200
603
882
1,480
2,180
1,410
38,400
17
78
Afterburner soot emission rate
mg/dscm at 7% O2
1.9
1.3
Notes: Each value (except condition 1 afterburner soot emissions) is the average of results for three test runs.
Ib/hr = Pounds per hour
kBtu/hr = Thousand British thermal units per hour
Btu/lb = British thermal units per pound
dscf/hr = Dry standard cubic feet per hour
mg/dscm = Millgram per dry standard cubic moter
CO = Carbon monoxide
NOx = Nitrogen oxides
O2 = Oxygen
ppm = Parts per million
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requirements. Combustion air is defined as the total air
entering the system (burner supplied air plus system
inleakages). Total system combustion air requirements,
estimated from stoichiometric calculations, were 5 percent
lower with the Sonotech system in operation.
Auxiliary Fuel Usage
Natural gas was used as the auxiliary fuel to maintain the
rotary kiln and afterburner temperatures. As shown in
Table 2, natural gas was supplied to both the main and
the Sonotech burners in the rotary kiln. In order to achieve
the target kiln exit gas temperature of 1,700 °F, a net heat
release rate of 1.0 to 1.2 million Btu/hr was needed.
Typically, to maintain an afterburner exit gas temperature
of 2,000 °F, an additional 1 -million Btu/hr heat release rate
was required in the afterburner. The average system total
natural gas usage from test to test was nearly equal. The
total system (kiln and afterburner) average natural gas
usage was 1,580 dry standard cubic feet per hour
(dscf/hr) for conventional combustion and 1,540 dscf/hr
for the Sonotech system.
Other Demonstration Results
Results of the test program in terms of the secondary and
other test objectives are summarized as follows:
• The frequency of transient carbon monoxide puffs,
as measured at the afterburner exit, was slightly
reduced when the Sonotech pulse combustor was
used.
The concentration of TUHC in the afterburner exit
flue gas was near the analytical detection limit.
Run-to-run and test-condition-to-test-condition
differences were minimal.
Target metals investigated included antimony,
barium, beryllium, cadmium, chromium, and lead.
These metals were present at low concentrations
in the feed material. They were also present at
low concentrations in the kiln ash, scrubber liquor,
and baghouse exit flue gas. Their distribution in
the kiln ash discharge did not vary significantly
from test to test or from test condition to test
condition. Concentrations of barium and
chromium in the scrubber liquor were slightly lower
and in the baghouse exit flue gas were higher with
the Sonotech system operating.
• Concentrations of target metals in the TCLP
leachates were low to not detected in the feed,
kiln ash, and scrubber liquor. At these
concentrations, no significant test-to-test
variations in the TCLP leachability of the various
discharge streams were observed.
The baghouse exit flue gas was sampled for
polychlorinated dibenzo-p-dioxins (PCDD) and
polychlorinated dibenzofurans (PCDF). No PCDD
and PCDF emissions were detected.
The RKS stack was sampled to measure hydrogen
chloride and particulate emissions for all 12 tests.
These measurements were performed to meet the
IRF operating permit requirements. Stack
particulate loading ranged from less than 0.5 to
2 milligrams per dry standard cubic
meter (mg/dscm) at 7 percent oxygen for the
12 tests and were considerably lower than the
maximum permit-allowed 180 mg/dscm.
Furthermore, there were no variations in the
particulate loading between the different test
conditions. Hydrogen chloride was not detected
in the flue gas emissions from any test. The
hydrogen chloride detection limit corresponds to
an emission rate of 0.2 g/hr.
The kiln ash was analyzed to determine its heating
value. As shown in Table 2, the heating value of
the residual kiln ash was reduced by greater than
64 percent with the Sonotech pulse combustor
operating.
Under the demonstration test conditions, the
Sonotech system can produce a cost savings due
to increased incinerator capacity. According to
Sonotech, the cost of a Sonotech pulse
combustion system, retrofit to an existing
full-scale incinerator, ranges from $60,000 to
70,000, depending on the application. The
estimated installation cost is $5,000, and the cost
of maintenance (including parts replacement,
preventive maintenance, and labor) is about
$2,500 per year. During the Sonotech
demonstration, the Sonotech combustion system
caused no downtime and was judged to be reliable.
Technology Status
The Sonotech technology has been tested under various
conditions, and it is currently commercially available for a
number of applications. According to Sonotech, Cello®
systems have been installed and operated at (1) Holnam
Cement Plant in La Porte, Colorado, where a pre-calciner
was retrofit with Sonotech's pulse combustion system,
and (2) at a confidential industrial location in California. A
field test of the Sonotech system was conducted at
Atlantic Steel facility in Cartersville, Georgia. Sonotech
plans to install and operate a Sonotech pulse system at
the Blue Circle Cement plant in Atlanta in July 1995.
Results from these tests are available from Sonotech,
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Length:
Volume:
Mass:
Energy:
Temperature:
Conversion Factors
English (US)
1 inch
1 foot
1 gallon
1 cubic foot
1 grain (gr)
1 pound (Ib)
1 ton (t)
1 British thermal unit (Btu)
1 million British thermal units
per hour (Btu/hr)
x
X
X
X
X
X
X
X
X
X
Factor
2.54
0.305
3.78
0.0283
64.8
0.454
907
1.05
290
(° Fahrenheit (°F) - 32)
0.556
Metric
centimeter (cm)
meter (m)
liter (L)
cubic meter (m3)
milligram (mg)
kilogram (kg)
kilogram (kg)
kilojoule (kj)
kilowatts (kW)
°Celsius °C
Disclaimer
The data and conclusions presented in this Technology
Capsule are preliminary and have not been reviewed by
the EPA Quality Assurance Office.
Sources of Further Information
Marta K. Richards
EPA Project Manager
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
Telephone: (513)569-7692
FAX: (513)569-7549
Zin Plavnik
Technology Manager
Sonotech, Inc.
575 Travis Street, N.W.
Atlanta, Georgia 30318
Telephone: (404) 525-8530
FAX: (404) 525-8533
10
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Environmental Protection Agency
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