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 hydrocarbons. This RPD process employs ultraviolet (UV) light in a reducing 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 longchain radical reactions with the hydrogenous bath gas leading to

the thermodynamically and kinetically favored hydrocarbon products at a conversion rate of 99%+.

The RPD process is schematically shown in Figure 1. The pilotscale 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-Cl bond and the temperature sustains long-chain radical

reactions. After a suitable residence time, conversion and dechlorination 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 Thermal (RT) (open bars) treatment under otherwise identical conditions. 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

EPA/540/F-94/508

August 1994

Emerging Technology Bulletin

Reductive Photo-Dechlorination (RPD) Process for Safe Conversion

of Hazardous Chlorocarbon Waste Streams

ENERGIA, Inc. of Princeton, New Jersey

United States

Environmental Protection

Agency

Figure 1. ENERGIA’s Reductive Photo-Dechlorination (RPD) process.

UV

light

Input /

mixer

Chlorocarbons

waste stream

Heating

Photo-thermal

reactor

HCI

scrubber

Separator

Hydrocarbons

Reducing gas

make-up Products

storage/sale

Reducing gas

recycle
BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35

United States

Environmental Protection Agency

Center for Environmental Research Information

Cincinnati, OH 45268

Official Business

Penalty for Private Use

$300

EPA/540/F-94/508

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 favorable results have been obtained for other saturated and unsaturated chlorocarbons treated by the RPD process.

Waste Applicability: The RPD Process can be effectively applied 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 chlorinated 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 benchtop developmental stage and is the basis on which a pilot-scale

prototype unit is being constructed. A demonstration SITE program 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 estimated cost is less than $1/lb. of treated chlorocarbon.

Business Opportunity: Energia is seeking a joint venture/industrial 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

100

80

60

40

20

0

% Selectivity

1,1-D

C

E

1,1-D

CA

C2H3CIC2H5CI

C

H4

C2H2C2H4C2H6C3H8

RT, Conversion = 99%+

Dechlorination = 51%+

RPD, Conversion = 99%+

Dechlorination = 99%+