The Maxymillian Technologies, Inc., Mobile Thermal Desorption System (TDS) uses rotary kiln technology to remove contaminants from soils. The TDS can remediate soils contaminated with volatile organic compounds (VOC), semivolatile organic compounds (SVOC), and polynuclear aromatic hydrocarbons (PAH). The TDS is fully transportable, requires a footprint of 100-by-140 feet, and can be set up on site in 4 to 6 weeks. The system combines high throughput with the ability to remediate mixed consistency soil, including sands, silts, clays, and tars.
The TDS consists of the following components (see figure below):
Soil is first shredded, crushed, and screened to achieve a uniform particle size of less than 0.75 inch. Feed soils are also mixed to achieve uniform moisture content and heating value.
The thermal treatment process involves two steps: contaminant volatilization followed by gas treatment. During the volatilization step, contaminated materials are exposed to temperatures ranging from 600 to 1,000 F in a co-current flow rotary kiln drum desorber; contaminants volatilize to the gas phase. Clean soils are then discharged through a multistage dust suppression system for remoisturization and are stockpiled for testing.
The gas and particulate stream passes from the kiln to the cyclone, where coarse particles are removed. The stream then enters the afterburner, which destroys airborne contaminants at temperatures ranging from 1,600 to 2,000 F. The gas stream is cooled by quenching before passing through a high-efficiency baghouse, where fine particles are removed. The clean gas is then released to the atmosphere through a 60-foot stack. Processed soil, after discharge from the dust suppression system, is stockpiled and allowed to cool prior to sampling.
The TDS is designed to remove a wide variety of contaminants from soil, including VOCs, SVOCs, PAHs, coal tars, and cyanide.
The TDS was accepted into the SITE Demonstration Program in 1993. The demonstration was conducted in November and December 1993 at the Niagara Mohawk Power Corporation Harbor Point site, a former gas plant in Utica, New York. During the demonstration, the TDS processed three replicate runs of four separate waste streams. Stack emissions and processed soil were measured to determine achievement of cleanup levels. The Demonstration Bulletin (EPA/540/MR-94/507) and Technology Capsule (EPA/540/R-94/507a) are available from EPA.
Following the SITE demonstration, the TDS was chosen to remediate approximately 17,000 tons of VOC-contaminated soil at the Fulton Terminals Superfund site in Fulton, New York. This project was completed in 1995. The system has since been moved to a location in North Adams, Massachusetts.
Results from the SITE Demonstration are summarized below:
EPA PROJECT MANAGER:
Ronald Lewis
U.S. EPA
National Risk Management Research Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7856
Fax: 513-569-7105
TECHNOLOGY DEVELOPER CONTACT:
Neal Maxymillian
Maxymillian Technologies, Inc.
84 State Street
Boston, MA 02109
617-557-6077
Fax: 617-557-6088