xvEPA
United States
Environmental Protection
Agency
EPA/540/F-94/508
August 1994
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Emerging Technology Bulletin
Reductive Photo-Dechlorination (RPD) Process for Safe Conversion
of Hazardous Chlorocarbon Waste Streams
ENERGIA, Inc. of Princeton, New Jersey
Technology Description: ENERGIA, Inc. of Princeton, New
Jersey has developed a novel technology designated "Reductive
Photo-Dechlorination" (RPD) for environmentally safe treatment
of waste streams containing hazardous chlorinated hydrocar-
bons. This RPD process employs ultraviolet (UV) light in a reduc-
ing atmosphere and at moderate temperatures to efficiently convert
chlorocarbon contaminants into valuable hydrocarbons such as
methane, ethane, ethylene and acetylene and hydrogen chloride.
The UV light promotes carbon-chlorine bond cleavage and long-
chain radical reactions with the hydrogenous bath gas leading to
the thermodynamically and kinetically favored hydrocarbon prod-
ucts at a conversion rate of 99%+.
The RPD process is schematically shown in Figure 1. The pilot-
scale prototype consists of five main units: (1) Input/Mixer; (2)
Photo-thermal Reactor; (3) Scrubber; (4) Separator/Storage; and
(5) Recycling. Chlorinated waste streams can be introduced in
one of three ways: liquid, vapor or adsorbates (to activated
carbon). Chlorocarbon solvents are fed into a vaporizer, mixed
with a reducing gas and passed into the Photo-thermal Reactor.
Air laden with chlorocarbon vapors is first passed through a
separator (condenser) which removes chlorinated materials as
liquid. Chlorinated contaminants adsorbed onto activated carbon
are removed as vapors by purging with a mildly heated reducing
gas. Then the vapors are passed into the Photo-thermal Reactor.
The Photo-thermal Reactor is the heart of the RPD technology.
Here the mixture is irradiated and heated. The UV light breaks
the C-CI bond and the temperature sustains long-chain radical
reactions. After a suitable residence time, conversion and dechlo-
rination are fully completed. Hydrogen chloride is scrubbed from
the mixture which proceeds to the separator. After separation,
excess reducing gas is recycled back to the Input/Mixer. Valuable
hydrocarbon products are collected and sold. There is also an
option for recycling a portion of the hydrocarbon products as an
auxiliary fuel to heat up the Photo-thermal Reactor.
Test Results: 1,1,1-Trichloroethane is a representative
chlorocarbon contaminant. Tests have demonstrated greater than
99% conversion and complete dechlorination. Figure 2, clearly
shows the advantage of RPD (black bars) over Reductive Ther-
mal (RT) (open bars) treatment under otherwise identical condi-
tions. In both cases conversion is 99%+. However, while the RT
is limited to 51%+ dechlorination, the RPD exhibits 99%+. It is
apparent that the RPD process is capable of safe and efficient
conversion of chlorinated hydrocarbon contaminants to valuable
Chlorocarbons
waste stream
Reducing gas
recycle
UV
light
Input /
mixer
Photo-thermal
reactor
Hydrocarbons
Reducing gas
make-up
Figure 1. ENERGIA's Reductive Photo-Dechlorination (RPD) process.
Products
storage/sale
Printed on Recycled Paper
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100
80
60
40
20 •
RT, Conversion = 99%+
Dechlorination = 51%+
RPD, Conversion = 99%+
Dechlorination = 99%+
Figure 2. Product selectivity obtained during treatment of 1,1,1-TCA with Reductive Thermal (RT) and Reductive Photo-Dechlorination (RPD).
hydrocarbon products (mainly ethane and methane). Similar fa-
vorable results have been obtained for other saturated and un-
saturated chlorocarbons treated by the RPD process.
Waste Applicability: The RPD Process can be effectively ap-
plied to liquid or gaseous waste streams containing saturated
and unsaturated chlorocarbons. It was tested for TCE, TCA,
DCE, DCA, vinyl chloride, ethyl chloride, DCM, and chloroform. It
may also be applicable to PCE, carbon tetrachloride, and chlori-
nated aromatics to be tested.
The RPD process is specifically cost-effective for the following
on-site remedial operations:
(1) In-situ treatment of chlorinated wastes discharged from
Soil Vapor Extraction (SVE).
(2) Direct treatment of Off-Gas streams containing
chlorocarbons.
(3) On-site regeneration of Activated Carbon saturated with
chlorocarbons removed by adsorption from waste
streams.
(4) Pretreatment of waste streams entering Catalytic Oxida
tion systems, reducing the chlorine content and thereby
promoting oxidation and longevity.
(5) Small-scale, on-site remediations in R&D and testing
laboratories, chemical hoods, clean rooms, etc.
Status: The RPD process has successfully completed the bench-
top developmental stage and is the basis on which a pilot-scale
prototype unit is being constructed. A demonstration SITE pro-
gram will follow after which the RPD technology will be available
for commercialization. Preliminary cost analysis shows that it is
extremely competitive with other remedial processes. Its esti-
mated cost is less than $1/lb. of treated chlorocarbon.
Business Opportunity: Energia is seeking a joint venture/indus-
trial partner to cost-share the demonstration project, which will be
funded, in-part, by EPA SITE program. Energia will consider
granting an exclusive license for the emerging RPD technology
in exchange for royalties.
For Further Information:
EPA Project Manager: Michelle Simon
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7469 Fax:513-569-7676
Technology Developer Contact:
Moshe Lavid ENERGIA, Inc.
P.O. Box 470
Princeton, NJ 08542
609-799-7970 Fax: 609-799-0312
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
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EPA
PERMIT No. G-35
EPA/540/F-94/508
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