vvEPA
United States
Environmental Protection
Agency
EPA/540/M5-89/006
April 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
Organic Extraction Utilizing Solvents
CF Systems Corporation
TECHNOLOGY DESCRIPTION: This technology
utilizes liquified gases as the extracting solvent to
remove organics, such as hydrocarbons, oil and
grease, from wastewater or contaminated sludges
and soils. Carbon dioxide is generally used for
aqueous solutions, and propane is used for sediment,
sludges and soils (semisolids).
Contaminated sediments are fed into the top of the
extractor (Figure 1). Solvent (condensed by
compression at 70 °F) flows upwards through the
extractor, making non-reactive contact with the
waste. Typically, 99 percent of the organics are
dissolved out by the solvent. Then, clean material is
removed from the extractor. A mixture of solvent and
organics leave the extractor, passing to the separator
through a valve where pressure is partially reduced.
In the separator, the solvent is vaporized and
recycled as fresh solvent. Finally, the organics are
Clean
Sediments
Organics
Figure 1. Solvent extraction unit process
diagram.
drawn off from the separator, recovered for disposal,
or reused off-site in industrial processes.
The difference in the mobile units for aqueous
solutions and semisolids can be found in the
extractor. For example, mixing variations can exist in
the extractor whereby aqueous solutions can go
through one type of mixer having a series of trays
while semisolids can go through a "cement-type"
mixer.
WASTE APPLICABILITY: This technology can be
applied to a wide variety of organics such as the
following: carbon tetrachloride, chloroform, benzene,
naphthalene, gasoline, vinyl acetate, furfural, butyric
acid, higher organic acids, dichloroethane, oils and
grease, xylene, toluene, methyl acetate, acetone,
higher alcohols, butanol, propanol, phenol, heptane,
PCBs and other complex organics.
STATUS: Currently, a pilot-scale system has been
tested on PCB-laden harbor sediments from the
Massachusetts New Bedford Harbor Superfund site
during September 1988. During the test, PCB
concentrations (ranging from 300 ppm to 5000 ppm)
and the number of passes through the unit were
varied for each of the four separate test runs. About
one-half drum (30 gallons) of sediments, with
additional water added to obtain the appropriate
consistency, was processed for each run. Results of
the demonstration will be available in several months.
DEMONSTRATION RESULTS: Demonstration of
this technology was conducted on PCB-
contaminated harbor sediment from New Bedford,
Massachusetts. The pilot-scale commercial unit
(PCU), rated at 20 bbl/day, was utilized at the site.
The PCU was a trailer mounted organic extraction
system for non-aqueous materials that used a
-------
vvEPA
United States
Environmental Protection
Agency
EPA/540/M5-89/006
April 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
Organic Extraction Utilizing Solvents
CF Systems Corporation
TECHNOLOGY DESCRIPTION: This technology
utilizes liquified gases as the extracting solvent to
remove organics, such as hydrocarbons, oil and
grease, from wastewater or contaminated sludges
and soils. Carbon dioxide is generally used for
aqueous solutions, and propane is used for sediment,
sludges and soils (semisolids).
Contaminated sediments are fed into the top of the
extractor (Figure 1). Solvent (condensed by
compression at 70°F) flows upwards through the
extractor, making non-reactive contact with the
waste. Typically, 99 percent of the organics are
dissolved out by the solvent. Then, clean material is
removed from the extractor. A mixture of solvent and
organics leave the extractor, passing to the separator
through a valve where pressure is partially reduced.
In the separator, the solvent is vaporized and
recycled as fresh solvent. Finally, the organics are
Sediments
Extractor
li
f^_*
Separ
Prop
« — -
1 ^
ator -
ane
—
\
1
d
Clean
Sediments
Organic*
Figure 1. Solvent extraction unit process
diagram.
drawn off from the separator, recovered for disposal,
or reused off-site in industrial processes.
The difference in the mobile units for aqueous
solutions and semisolids can be found in the
extractor. For example, mixing variations can exist in
the extractor whereby aqueous solutions can go
through one type of mixer having a series of trays
while semisolids can go through a "cement-type"
mixer.
WASTE APPLICABILITY: This technology can be
applied to a wide variety of organics such as the
following: carbon tetrachloride, chloroform, benzene,
naphthalene, gasoline, vinyl acetate, furfural, butyric
acid, higher organic acids, dichloroethane, oils and
grease, xylene, toluene, methyl acetate, acetone,
higher alcohols, butanol, propanol, phenol, heptane,
PCBs and other complex organics.
STATUS: Currently, a pilot-scale system has been
tested on PCB-laden harbor sediments from the
Massachusetts New Bedford Harbor Superfund site
during September 1988. During the test, PCB
concentrations (ranging from 300 ppm to 5000 ppm)
and the number of passes through the unit were
varied for each of the four separate test runs. About
one-half drum (30 gallons) of sediments, with
additional water added to obtain the appropriate
consistency, was processed for each run. Results of
the demonstration will be available in several months.
DEMONSTRATION RESULTS: Demonstration of
this technology was conducted on PCB-
contaminated harbor sediment from New Bedford,
Massachusetts. The pilot-scale commercial unit
(PCU), rated at 20 bbl/day, was utilized at the site.
The PCU was a trailer mounted organic extraction
system for non-aqueous materials that used a
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