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CF SYSTEMS CORPORATION
(Liquified Gas Solvent Extraction [LG-SX] Technology)

This vendor is participating in the EPA Superfund Innovative 
Technology Evaluation (SITE) Program.  The following technology 
profile has been reproduced from the SITE Technology Profile 
document, 7th edition.  The SITE profile has been supplemented by 
MVA Consulting Inc. using information obtained from the vendor or 
from other SITE publications, referenced at the end of this file. 

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TECHNOLOGY DESCRIPTION:

The CF Systems Corporation's LG-SX technology uses liquified gas
solvents to extract organics from soils, sludges, sediments, and
wastewaters.  Gases, when liquified under pressure, have unique
physical properties that  enhance their use as solvents.  The low
viscosities, densities, and surface tensions of these gases
result in significantly higher rates of extraction compared to
conventional solvents.  These enhanced physical properties also
accelerate treated water's gravity settling rate following
extraction.  Due to their high volatility, gases are also easily
recovered from the aqueous solids matrix, minimizing solvent
losses.

Liquified propane solvent is typically used to treat soils,
sludges, and sediments, while liquified carbon dioxide is
typically used to treat wastewater.  The extraction system uses a
batch extractor-decanter design for solids and sludges, and a
continuous trayed tower design for waste-waters and low solids
wastes.  Typical treatment costs for non-pumpable soils and
sludges range from $80 to $300 per ton of feed, excluding
excavation and disposal.

Contaminated solids, slurries, or wastewaters are fed into the
extraction system along with solvent (see figure below). 
Typically, more than 99 percent of the organics are extracted
from the feed.  After the solvent and organics are separated from
the treated feed, the solvent and organic mixture passes to the
solvent recovery system.  Once in the solvent recovery system,
the solvent is vaporized and recycled as fresh solvent.  The
organics are drawn off and either reused or disposed of.  Treated
feed is discharged from the extraction system as a slurry in
water.

WASTE APPLICABILITY:

The LG-SX technology can be applied to soils and sludges
containing volatile and semivolatile organic compounds and other
higher boiling complex organics, such as polynuclear aromatic
hydrocarbons, polychlorinated biphenyls (PCB), dioxins, and
pentachlorophenol.  This process can also treat refinery wastes
and wastewater contaminated with organics.

STATUS:

Under the SITE Program, a pilot-scale mobile demonstration unit
was tested in 1988 on PCB-laden sediments from the New Bedford
Harbor Superfund site in Massachusetts.  PCB concentrations in
the harbor sediment ranged from 300 parts per million (ppm) to
2,500 ppm.  The Technology Evaluation Report (EPA/540/5-90/002)
and the Applications Analysis Report (EPA/540/A5-90/002) were
published in August 1990.

A pilot-scale treatability study was recently  completed on a
PCB-contaminated soil for a Michigan Superfund site.  Initial
analytical data shows that treatment achieved levels of residual
PCBs well below the 1 ppm cleanup level required for site
closure.

CF Systems Corporation completed the first commercial on-site
treatment operation at Star Enterprise, in Port Arthur, Texas. 
The propane-based solvent extraction unit processed listed
refinery K- and F-wastes, producing Resource Conservation and
Recovery Act treated solids that met EPA land-ban requirements. 
The unit operated continuously from March 1991 to March 1992 and
was on-line more than 90 percent of the time.  Following heavy
metals fixation, the treated solids were disposed of in a Class I
landfill.

EPA Region 6 and the Texas Water Commission have selected the
LG-SX 
technology on a sole-source basis to cleanup the 80,000 cubic
yard United Creosoting site in Conroe, Texas.  This Superfund
site is heavily contaminated with wood treatment wastes. 
Detailed design is scheduled to begin in late 1994.

DEMONSTRATION RESULTS:

This technology was demonstrated concurrently with dredging
studies managed by the U.S. Army Corps of Engineers. 
Contaminated sediments were treated by the CF Systems Pit Cleanup
Unit, using a liquified propane and butane mixture as the
extraction solvent.  Extraction efficiencies were high, despite
some operating difficulties during the tests.  The demonstration
at the New Bedford site yielded the following results:

>  Extracted sediments were at 90 to 98 percent efficiency
   for sediments containing PCBs between 360 and 2,575 ppm. 
   
>  PCB concentrations were as low as 8 ppm in the treated
   sediment.

>  In the laboratory, volatile and semivolatile organics in
   aqueous and semisolid wastes were extracted with 99.9
   percent efficiency.
   
>  Operating problems included solids retention in the system
   hardware and foaming in receiving tanks.  The problems
   were corrected in the full-scale operations at Star
   Enterprises.
   
>  Projected costs for PCB cleanup were estimated at $150 to
   $450 per ton, including material handling and pre- and
   posttreatment costs.  These costs are highly dependent on
   the utilization factor and job size, which may result in
   lower costs for large cleanups.

FOR FURTHER INFORMATION:

EPA PROJECT MANAGER:
Mark Meckes
U.S. EPA
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH  45268
513-569-7348
Fax: 513-569-7676

TECHNOLOGY DEVELOPER CONTACT:
Chris Shallice
CF Systems Corporation
3D Gill Street
Woburn, MA  01801
617-937-0800, ext. 103
Fax: 617-937-5610
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Sources of information in this profile:

EPA Superfund Innovative Technology Evaluation Program 
        Technology Profiles Seventh Edition, November 1994. 
        EPA/540/R-94/526.

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