&EPA
                                  United States
                                  Environmental Protection
                                  Agency
                EPA/540/M R-92/078
                November 1992
                                 SUPERFUND INNOVATIVE
                                 TECHNOLOGY EVALUATION
                                  Demonstration Bulletin
                                                            i
                           SoilTech Anaerobic Thermal Processor:
                               Outboard Marine Corporation Site

                                      SoilTech ATP Systems, Inc.
Technology Description: The anaerobic thermal processor
(ATP) was developed by UMATAC Industrial Processes under
the sponsorship of the Alberta Oil Sands Technology and Re-
search Authority  (AOSTRA). The  technology  is licensed by
SoilTech ATP Systems, Inc. (SoilTech), a U.S. corporation. The
ATP technology uses a physical separation process to thermally
desorb organics such as polychlorinated biphenyls (PCBs) from
soils, sediments, and  sludges. The ATP system was used to
remove PCBs from contaminated soils and sediment at the Out-
board Marine Corporation (OMC) site in Waukegan, IL.

The ATP system mixes and heats contaminated soils, sediments,
and sludges in the processing unit. The processor consists of
four separate thermal zones: the preheat, retort, combustion, and
cooling zones. Figure  1  presents a sectional  diagram of the
processor showing the four internal zones. The  unit is designed
to operate at temperatures of 400 to 650 °F in the preheat zone;
900 to 1,150 °F in the retort zone; 1,200  to  1,450 °F in the
combustion zone; and 500 to 800 °F in the cooling zone.
Temperatures in the preheat zone cause water and volatile or-
ganic compounds (VOC) in the waste to vaporize. Water vapor
and evaporated contaminants are removed by vacuum and enter
a preheat vapor cooling system, which consists of a cyclone,
condenser, and three-phase preheat separator. Recovered water
is sent to an onsite treatment system. Light organic vapors that
are riot condensed are then fed by a blower directly into the
combustion zone of the processor. Condensed organic com-
pounds are combined with condensate from the retort vapor
cooling system.

Hot, granular solids exiting the preheat zone pass through a sand
seal and enter the retort zone. The higher temperatures in the
retort zone cause (1) heavy oils  to vaporize and (2) thermal
cracking  of hydrocarbons, which forms coke and low molecular
weight gases. Vapor from the retort zone is removed by vacuum
and passes  through  a pair of  cyclones  to remove entrained
particles. These dusts and fines are blended with the treated soil.
The vapor is cooled by oil circulating in two packed columns; the
  Flue Gas Discharge
  to Flue Gas     ^
  Treatment System \~
  Steam and Light
  Organic Vapors to
  Vapor Cooling
  System

          Feed
          Stocks
Cooling Zone
<--- <- 	 < 	
Preheat Zone
\
\
\ j>
\ jS1^
', Sand Seal
\
•<-^s
N
\
I Evolved Steam and ^
\ Light Organic Vapors '



Combustion Zone
< 	 <--p- <..x
Flue Gas \
\
f f ft*.

Retort Zone
;•
i
1

, > - •• • > - - - *•
y
f
i
Heavy Organic
^Vapors
\
S" (

H" '""i.
A
1
\
\
\ 0
f
       Treated
        Solids
Treated Solids /""
	 V
\^~~~" Solids Recycle ./
Coked Solids
—
                      Heavy Organic
                      Vapors to Vapor
                      Cooling System
                                                                              Auxiliary
                                                                              Burners
                                                                              Combustion
                                                                                 Air
Key
                                       Gas Streams
                                                                                              Solid Streams
                          Kiln End Seals
Figure 1. Simplified section diagram showing the four internal zones.
                                                                                    Printed on Recycled Paper

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columns act as a two-stage direct-contact condenser for com-
pounds w'rth high boiling points. The remaining vapors then pass
through a water-cooled noncontact condenser and a three-phase
separator. The remaining uncondensed gases are returned to the
combustion chamber of the treatment system. The condensed oil
phase  Is returned to the packed columns.  Condensed water is
pumped directly to the onsite treatment system.

The  coked solids pass through  a second  sand seal into  the
combustion zone. During the OMC site remediation, sodium bicar-
bonate was added to the coked solids to minimize the potential for
the emission of PCBs from the ATP system. In the combustion
zone, the coked solids are combusted and either recycled to
provide heat to the retort zone, or sent to be cooled in the cooling
zone. Flue gas from the combustion zone is treated in a cyclone
and baghouse to remove particles and a carbon adsorption sys-
tem to remove trace  organics. Treated flue gas is then discharged
to the  atmosphere  through a stack.  Treated  soils  exiting  the
cooling  zone are quenched with  tap water and are then trans-
ported by conveyor to an outside storage pile.

Waste Applicability: SoilTech reports the following specifica-
tions for the ATP system. The transportable ATP unit is capable
of processing about  10 tons of contaminated soil or sediment per
hour. The optimal moisture content of the waste to be treated is
between 5% and 10% by weight. Wastes w'rth a moisture content
up to 20% can be  treated, but  the high  moisture content  will
reduce  net throughput rates.  Wastes with  a moisture content
greater than 20% may need to be dewatered to optimize process
economics.

The ATP system is also designed to treat wastes with a nominal
hydrocarbon concentration of 10%. The ATP is capable of treating
wastes  containing contaminants  w'rth a wide  range  of  boiling
points. Heavy oil contaminants have been reduced from as high
as 60% In the untreated waste to near detection limits in treated
solids.

Demonstration Results:  In June  1992, the ATP technology
was demonstrated during full-scale remediation of the OMC site in
Waukegan, IL Three  replicate test runs were conducted at the
typical operating conditions used during the OMC site remediation.
Each test run consisted of 8.5 hours of solids and liquids sampling
and  8  hours of stack sampling. A total of 224 tons of PCB-
contaminated soil and sediment was treated in the SoilTech ATP
during the SITE demonstration. Extensive process operating data
were collected during the demonstration to document the operat-
ing conditions of the ATP process.

Key findings from the OMC site demonstration include the follow-
ing:

  • PCB concentrations were reduced from an average of 9,761
    parts per million (ppm) in the untreated soil and sediment to an
    average concentration of 2 ppm in the treated soil and sedi-
    ment.
  • Approximately 0.12 milligrams (mg) of PCBs were discharged
    from the ATP system's stack per kilogram of PCBs fed to the
    ATP.
  • The majority of PCBs removed from the untreated soil and
    sedimentwere accumulated in the waste oil dischargefrom the
    vapor cooling system.
  • No dioxins.otherthan a low concentration [0.1 nanograms (ng)
    perdry standard cubic meter (dscm)] of octachlorinated dibenzo-
    p-dioxin in one stack gas sample, were detected in the stack
    gas from the ATP system. Tetrachlorinated dibenzofurans
    were found in both the untreated soil and sediment  (88 ng/g)
    and treated soil and sediment (5 ng/g), and the stack gas (0.07
    ng/dscm).
  • Leachable VOCs, semivolatile organic compounds,  and met-
    als  in the treated soil and sediment were below Resource
    Conservation and Recovery Act toxicity characteristic stan-
    dards.
  • No operational problems affecting the ATP's ability to treat the
    contaminated soil and sediment were observed.

An Applications Analysis Report  and a Technology Evaluation
Report describing the complete SoilTech ATP  SITE demonstra-
tion will be available in the Spring of 1993.

For Further Information:

EPA Project Manager:
Paul R. dePercin
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7797
     United States
     Environmental Protection Agency
     Center for Environmental Research Information
     Cincinnati, OH 45268

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