(Anaerobic Thermal Processor)
The SoilTech ATP Systems, Inc. (SoilTech), anaerobic thermal processor (ATP) uses a rotary kiln to desorb, collect, and recondense contaminants or recyclable hydrocarbons from a wide variety of feed material (see figure below).
The proprietary kiln contains four separate internal thermal zones: preheat, retort, combustion, and cooling. In the preheat zone, water and volatile organic compounds (VOC) are vaporized. The hot solids and heavy hydrocarbons then pass through a proprietary sand seal to the retort zone. The sand seal allows solids to pass and inhibits gas and contaminant movement from one zone to the other. Concurrently, hot treated soil from the combustion zone enters the retort zone through a second sand seal. This hot treated soil provides the thermal energy necessary to desorb the heavy organic contaminants. The vaporized contaminants are removed under slight vacuum to the gas handling system. After cyclones remove dust from the gases, the gases are cooled, and condensed oil and water are separated into their various fractions.
The coked soil passes through a third sand seal from the retort zone to the combustion zone. Some of the hot treated soil is recycled to the retort zone through the second sand seal as previously described. The remainder of the soil enters the cooling zone. As the hot combusted soil enters the cooling zone, it is cooled in the annular space between the outside of the preheat zone and the kiln shell. Here, the heat from the combusted soils is transferred indirectly to the soils in the preheat zone. The cooled, treated soil exiting the cooling zone is quenched with water and conveyed to a storage pile.
Flue gases from the combustion zone pass through the cooling zone to an emission control system. The system consists of a cyclone and baghouse to remove particulates, a wet scrubber to remove acid gases, and a carbon adsorption bed to remove trace organic compounds.
The system treats soils, sediments, and sludges contaminated with compounds
that vaporize at temperatures up to 1,100 °F. Treated solids are free
of organics and suited for backfill on site. Applicable contaminants include
the following:
This technology was accepted into the SITE Demonstration Program in 1991. The ATP has been demonstrated at two sites. At the first demonstration, in May 1991, a full-scale unit dechlorinated PCB-contaminated soil at the Wide Beach Development Superfund site in Brant, New York. At the second demonstration, completed in June 1992, a full-scale unit remediated soils and sediments at the Waukegan Harbor Superfund site in Waukegan, Illinois. Two additional Superfund sites in Ohio and Kentucky have since been remediated by the ATP. Soils at these sites were contaminated with PCBs, PAHs, and pesticides.
The ATP has been used to treat more than 100,000 tons of waste on four separate sites. The system has operated in compliance with state and federal regulations in New York, Illinois, Ohio, and Kentucky. SoilTech is currently negotiating with a confidential client to remediate 25,000 cubic yards of trichloroethene- (TCE) and PCB-contaminated soil at a site located in Pennsylvania.
SoilTech is continuing its research into more diverse organic remediation applications and bitumen recovery.
Test results from both SITE demonstrations indicate the following:
EPA PROJECT MANAGER:
Paul dePercin
U.S. EPA
National Risk Management Research Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7797
Fax: 513-569-7105
E-Mail:
dePercin.Paul@epamail.epa.gov
TECHNOLOGY DEVELOPER CONTACTS:
Joseph Hutton
Smith Environmental Technologies Corporation
304 Inverness Way South, Suite 200
Englewood, CO 80112
303-790-1747
Fax: 303-799-0186