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 DEHYDRO-TECH CORPORATION
(Carver-Greenfield Process  for Solvent Extraction of
Wet, Oily Wastes)

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. 


TECHNOLOGY DESCRIPTION:

The Carver-Greenfield Process  (C-G Process ) combines solvent
extraction and dehydration technologies to separate wet, oily
wastes into their constituent solid phase, water phase, and
hydrocarbon-soluble indigenous oil phase.

Waste is first mixed with a low cost hydro-carbon solvent, and
the resultant slurry mixture is fed to an evaporator system that
vaporizes water and initiates solvent extraction of the
indigenous oil.  Depending on the water content of the feed,
single-effect or energy-saving multi-effect evaporators may be
used.  Next, the slurry of dried solids is treated in a
multi-stage 
solvent extraction unit, where solids contact recycled
solvent until the target amount of indigenous oil is removed.

Finally, solids are centrifuged from the solvent, followed by
"desolventizing," a step where resi-dual solvent is evaporated. 
The final solids pro-duct typically contains less than two
percent water and less than one percent solvent.  The spent
solvent, which contains the extracted indi-genous oil, is
distilled to separate the solvent for reuse later, and the oil
for recovery or disposal.

The C-G Process yields 1) a clean dry solid, 2) a water product
virtually free of solids, indigenous oil, and solvent, and 3) the
extracted indigenous oil which contains the hazardous
hydrocarbon-soluble feed components.

The C-G Process combination of water eva-poration and solvent
extraction has the following advantages:  1) any emulsions
initially present are broken and potential emulsion formation
prevented; 2) solvent extraction is more efficient than with
water present; and 3) the dry solids product is stabilized more
readily if metals contamination is a concern.

WASTE APPLICABILITY:

The C-G Process can treat sludges, soils, sediments, and other
water-bearing wastes containing hydrocarbon-soluble hazardous
compounds, including polychlorinated biphenyls, polynuclear
aromatic hydrocarbons, and dioxins.  The process has been
commercially applied to municipal wastewater sludge, paper mill
sludge, rendering waste, pharmaceutical plant sludge, and other
wastes.

STATUS:

The C-G Process was accepted into the SITE program in 1990.  The
pilot-scale SITE demonstration of this technology was completed
in August 1991 at EPA's research facility in Edison, New Jersey. 
Spent petroleum drilling fluids from the PAB oil site in Abbe-
ville,  Louisiana, were used as process feed.  The Applications
Analysis Report (EPA/540/AR-92/002), Technology Demonstration
Summary (EPA/540/SR-92/002), and Technology Evaluation Report
(EPA/540/SR-92/002) were issued in 1992.

DEMONSTRATION RESULTS:

Based on spent drilling fluids, the C-G Process yielded the fol-
lowing SITE demonstration results:

>  The process successfully separates a petroleum-oil
   contaminated sludge into its solid, indigenous oil, and water
   phases.  No detectable levels of indigenous total petroleum
   hydrocarbons are present in the final solid product.

>  The final solid product is a dry powder similar to bentonite. 
   A food-grade solvent comprises the bulk of the residual
   hydrocarbons on the solid.

>  Values for all metals and organics are well below the
   Resource Conservation and Recovery Act toxicity
   characteristic leaching procedure limits for characteristic
   hazardous wastes.

>  The resulting water product requires treatment due to the
   presence of small amounts of light organics and solvent. 
   Normally, it may be disposed of at a local publicly owned
   treatment works.

>  A full scale C-G Process can treat drilling fluid wastes at
   technology-specific costs of $100 to $220 per ton of wet
   feed, exclusive of disposal costs for the residuals.  
   Site-specific costs, which include the cost of residual
disposal,
   are dependent on site characteristics and treatment
   objectives.

FOR FURTHER INFORMATION:

EPA PROJECT MANAGER:
Laurel Staley
U.S. EPA
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH  45268
513-569-7863
Fax: 513-569-7620

TECHNOLOGY DEVELOPER CONTACT:
Theodore Trowbridge
Dehydro-Tech Corporation
6 Great Meadow Lane
East Hanover, NJ  07936
201-887-2182
Fax: 201-887-2548

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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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