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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                          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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