vvEPA
United States
Environmental Protection
Agency
EPA/540/MR-92/008
March 1992
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
AOSTRA-SoilTech Anaerobic Thermal Processor:
Wide Beach Development 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) and is licensed by SoilTech ATP
Systems, Inc., a U.S. corporation. The ATP technology involves
a physical separation process that thermally desorbs organics
such as polychlorinated biphenyls (PCBs) from soil and sludge.
The ATP process was used in conjunction with optional
dehalogenation reagents to chemically treat over 42,000 tons of
PCB-contaminated soils at the Wide Beach Development site in
Brant, New York. For this demonstration, the contaminated soils
are sprayed with a diesel fuel and oil mixture containing alkaline
polyethylene glycol (APEG) reagents before entering the preheat
zone. The oil mixture acts as a carrier for the dehalogenation
reagents.
In the preheat zone (400-650° F), water and volatile organic
compounds (VOC) vaporize (Figure 1). At the same time, the
reagents dehalogenate or chemically break down chlorinated
compounds (including PCBs). The vaporized contaminants and
water are removed via a vacuum to a preheat vapor cooling
system consisting of a cyclone, condenser, and 3-phase preheat
separator. The noncondensed light organic vapors are then fed
by a blower directly into the combustion chamber of the proces-
sor. The oil fraction is recycled to a reagent blending tank, and
recovered water is sent to the onsite treatment system.
From the preheat zone, the hot, granular solids pass through a
sand seal to the retort zone (900-1,150° F). Here heavy oils
vaporize, and thermal cracking of hydrocarbons forms coke and
low molecular weight gases. The vapor stream from the retort
zone is removed via a vacuum and passes first through a two-
stage pair of cyclones to remove entrained particles. The vapor
is then cooled by oil circulating in two packed columns, acting as
a two-stage direct contact condenser for the higher boiling point
compounds. The uncondensed vapors are then cooled in a
water-cooled noncontact condenser and pass through a 3-phase
Flue Gas
Discharge
j
I - —
Cooling Zone
Low Temp. L -
Steam and — I
Hydrocarbon
Combustion Zone
..... ..... ,
Flue Gas
Key
Gas Streams
Solid Streams
Coked Solids
Preheat Zone
Vapors Flow~l \ Sand Seal
J
Feed
Stocks
Evolved Steam \
and Organics
Spent Solid
Tailings
Spent Solids
Hydrocarbon
and Steam
Vapors Flow
~ Auxiliary
Burners
Combustion
Air Flow
Kiln End Seals
Figure 1. Simplified sectional diagram showing the four internal zones.
Printed on Recycled Paper
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separator. The final noncondensable gases are returned to the
combustion chamber of the process. The oil phase is combined
with the condensate from the packed columns. This oil conden-
sate is then sent to the reagent blending unit to mix with the
APEG reagents. The blend is pumped at a measured rate and is
applied to the untreated soils in the feed chute of the processor.
Condensed water is pumped directly to the ons'rte treatment
system.
The coked soils pass through a second sand seal into the
combustion zone (1,200-1,450° F). Here the coked soils are
combusted and either recycled to the retort zone or sent to be
cooled in the cooling zone. Flue gas from the combustion zone
Is treated in a system consisting of a cyclone and baghouse that
remove particulates; a scrubber that removes acid gases; and a
carbon adsorption bed that removes trace organics. The treated,
flue gas is then discharged to the atmosphere through a stack.
Treated soils exiting the cooling zone (500-800° F) are quenched
with water and are then transported by conveyor to an outside
storage pile.
Waste Applicability: SoilTech reports the following specifica-
tions of the ATP system. The optimal moisture content of the
waste to be treated is between 5 and 10 weight percent. Wastes
with a moisture content up to 20 percent can be treated, but will
impact the net throughput rates. Wastes with a moisture content
greater than 20 percent 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 percent.
Heavy oil contaminants have been reduced from as high as 60
percent in the feed to near detection limits in the treated solids.
The rate of contaminant desorption and dechlorination from soils
and sediment is influenced by the contaminant concentration.
SoilToch reports that the contaminant concentration in the treated
solids is generally independent of the contaminant concentration
in the feed waste and will be near the detection limit for the
contaminant. The processor treats wastes containing contami-
nants with tow boiling points more effectively than wastes con-
taining contaminants with high boiling points. However, high boil-
ing point organics such as PCBs and polycyclic aromatic hydro-
carbons can be removed to concentrations below detection limits
of 1 part per million (ppm).
Demonstration Results: The ATP technology was demon-
strated at the Wide Beach Development Superfund site in Brant,
New York, in May 1991. Three test runs were conducted during
the SITE demonstration, each 5Vz hours. The solid and liquid
locations that were sampled during each run were contaminated
feed soil, treated soil, combined flue gas cyclone fines and
baghouse dust, preheat vapor cyclone fines, scrubber liquor,
condensed water before and after treatment, vapor scrubber oil,
and preheat oil. The noncondensed preheat and retort off-gases
were also sampled during each run.
Laboratory analyses included analyses of the solids and liquids
for PCBs, dioxins/furans, VOCs, and semivolatile organics
(SVOCs) to determine the PCB removal efficiency of the proces-
sor, the potential degradation products of the PCBs, and the
potential formation of dioxins and furans. Total chlorides and
total organic halogens (TOX) were also analyzed in an attempt to
trace the fate of chlorine throughout the system. In addition, a
variety of other parameters were analyzed to characterize the
feed and treated soils.
Key findings from the Wide Beach site demonstration are sum-
marized below:
• The SoilTech ATP unit removed PCBs in the contaminated
soil to levels below the desired cleanup concentration of 2
ppm. PCB concentrations were reduced from an average
concentration of 28.2 ppm in the contaminated feed soil to
an average concentration of 0.043 ppm in the treated soil.
• The SoilTech ATP does not appear to create dioxins and/or
furans.
• No volatile or semivolatile organic degradation products
were detected in the treated soil. There were also no
leachable VOCs or SVOCs detected in the treated soil.
• No operational problems affecting the ATP's ability to treat
the contaminated soil were observed.
For Further Information:
EPA Project Manager:
Paul R. de Percin
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7797 (FTS: 684-7797)
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/540/MR-92/008
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