&EPA
United States
Environmental Protection
Agency
EPA/540/SR-93/522
September 1994
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Technology Demonstration
Summary
ECO LOGIC International Gas-
Phase Chemical Reduction
Process and Thermal Desorption
Unit, Middleground Landfill, Bay
City, Ml
ELI Eco Logic International, Inc. (ECO
LOGIC) has developed a gas-phase
chemical reduction process (reactor),
along with a companion thermal des-
orption unit (TDU), for the treatment of
liquids and soils contaminated with
polychlorinated biphenyls (PCBs) and
other chlorinated compounds. Under
the auspices of the Superfund Innova-
tive Technology Evaluation (SITE) Pro-
gram, and in cooperation with the city
of Bay City (Michigan), Environment
Canada, and the Ontario Ministry of the
Environment and Energy, the EPA con-
ducted the demonstration of the ECO
LOGIC process at Bay City's
Middleground Landfill during 28 days
in October through December, 1992.
This Summary was developed by
EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the SITE program dem-
onstration that is fully documented in
separate reports (see ordering infor-
mation at back).
Introduction
In 1986, the U.S. Environmental Pro-
tection Agency's Office of Solid Waste
and Emergency Response (OSWER) and
the Office of Research and Development
(ORD) established the SITE program to
promote the development and use of in-
novative technologies to clean up Super-
fund sites across the country. The SITE
program includes four major elements: the
Demonstration Program, the Emerging
Technologies Program, the Measurement
and Monitoring Technologies Program, and
the Technology Transfer Program.
One SITE component, the Demonstra-
tion Program, provides reliable engineer-
ing, performance, and cost data on
selected hazardous waste technologies.
This information, used in conjunction with
other data, enables EPA and state deci-
sion-makers to select the most appropri-
ate technology for Superfund cleanups.
The three-part SITE demonstration of
the ECO LOGIC process was conducted
at the Middleground Landfill in Bay City,
Printed on Recycled Paper
-------
Ml, during 26 days in October through
December, 1992. The first part (Test Con-
ditions 1 and 3) evaluated only the reactor
system as it processed liquids; the sec-
ond part (Test Condition 2) evaluated the
TDU in combination with the reactor; the
third part consisted of a 72-hr engineering
performance test.
EPA established the following program
objectives:
• Demonstrate at least 99.9999% de-
struction and removal efficiency (DRE)
for polychlorinated biphenyls (PCBs).
• Demonstrate at least 99.99% destruc-
tion efficiency (DE) for perchloroeth-
ylene (PCE), the tracer in the liquid
feedstock, and hexachlorobenzene
(HCB), the tracer in the solid feed.
• Ensure that no dioxins or furans were
formed.
• Characterize products of incomplete
combustion (PIC) in emissions.
• Characterize hydrogen chloride (HCI)
in emissions.
• Document compliance with Michigan
Department of Natural Resources
(MDNR) air permit conditions.
• Characterize criteria air pollutant emis-
sions.
• Document compliance with Toxic Sub-
stances Control Act (TSCA) permit
requirements.
• Validate key cost assumptions used
in process economic analyses.
• Characterize effluents and residual
streams relative to disposal require-
ments.
• Determine the suitability of the re-
formed gases for reuse/resale.
• Demonstrate system reliability.
• Develop a system mass balance, in-
cluding metals.
• Characterize critical process scale-up
parameters.
• Validate the performance of ECO
LOGIC'S on-line Chemical lonization
Mass Spectrometer (CIMS).
• Document system operation during
test runs.
Technology Description
The ECO LOGIC gas-phase chemical
reduction process (reactor) treats liquid
organic hazardous waste in a hydrogen-
rich atmosphere at approximately 900°C
(1,650°F) temperature and ambient pres-
sure to produce a high BTU reformed gas
product. The process is well suited for
aqueous waste streams as water acts as
a hydrogen donor to enhance the reduc-
tion reaction. The reaction products in-
clude HCI, from the reduction of chlorinated
organics, such as PCBs, and lighter hy-
drocarbons, such as methane and ethyl-
ene, from the reduction of straight-chain
and aromatic hydrocarbons. The absence
of free oxygen in the reactor inhibits di-
oxin formation.
The ECO LOGIC reactor can be com-
bined with their patented TDU, which treats
organic hazardous wastes in solid and
liquid media. The TDU processes soil by
desorbing organics at 500 to 600°C (930
to 1,100°F) using a molten metal bath as
a heat transfer medium. Organics are de-
sorbed into a hydrogen-rich carrier gas.
Most volatile metals found within soils will
be dissolved into the molten metal bath,
some will pass to the reactor with the
carrier gas, and the remainder will stay in
the treated soil. Nonvolatile metals remain
in the treated soil; quench water cools the
soil before disposal. The hydrogen-rich
carrier gas conveys the desorbed organ-
ics to the reactor (Figure 1), where they
are treated in a gas-phase chemical re-
duction reaction to produce reformed gas.
Figure 2 illustrates the ECO LOGIC pro-
cess in a schematic diagram of the dem-
onstrated unit.
For the reactor demonstration, a heat
exchanger evaporated contaminated aque-
ous feedstock to form steam and a con-
centrated heated liquor. Atomizing nozzles
sprayed the heated liquor, with associ-
ated particulates, into the reactor. A sepa-
rate pump sent PCB-rich oils directly to
the reactor through other atomizing
nozzles. Compressed, hydrogen-rich, re-
circulating gas passed through a gas-fired
heat exchanger and entered the top of the
reactor tangentially. The tangential entry
swirled the fluids to provide effective mix-
ing. As indicated in Figure 1, the swirling
mixture traveled downward in the annulus
formed by the reactor wall and the central
ceramic-coated steel tube, past electrically
heated bars. These bars heated the mix-
ture to 900°C (1,650°F). At the bottom of
the reactor the mixture entered the tube,
reversed direction, and flowed upward to
the outlet of the reactor. The reduction
reactions occurred as the gases traveled
from the reactor inlets to the scrubber
inlet.
After quenching, the gases flowed
through a scrubber where contact with
water removed HCI and fine particulates.
A large water-sealed vent, acting as an
emergency pressure relief duct, passed
scrubber water to a tank below. A pump
recirculated the scrubber water through
an evaporative cooler to reduce its tem-
perature to 35°C (95°F). Caustic and
rnake-up water, added to the scrubber
liquor, maintained HCI removal efficiency.
The scrubber produced two effluent
streams, sludge and decant water.
The reformed gas exiting the scrubber
contained excess hydrogen, lighter hydro-
carbon reduction products such as meth-
ane and ethylene, and a small amount of
water vapor. Approximately 95% of this
hydrogen-rich gas was reheated to 500°C
(930°F) and recirculated back into the re-
actor; about 5% of the gas served as
supplementary fuel for a propane-fired
boiler used to produce steam. The boiler,
which burned a mixture of propane and
reformed gas, generated the only air emis-
sions from the process.
When treating wastes containing highly
concentrated organics, the process gen-
erates excess reformed gas. The system
operator can elect to compress the ex-
cess reformed gas and store it for later
use or analysis.
Site Preparation
The demonstration-scale reactor was 2
m (6 ft) in diameter and 3 m (9 ft) tall,
mounted on a 15 m (45 ft) drop-deck
trailer. The trailer carried a scrubber sys-
tem, recirculation gas system, and an elec-
trical control center. A second trailer held
a propane boiler and a waste preheating
vessel. The TDU traveled on a third flat-
bed trailer.
The ECO LOGIC system requires a fairly
level area, approximately 120 ft x 180 ft,
for the processing and auxiliary equip-
ment. ECO LOGIC arranged the reactor,
TDU, and support equipment trailers in
parallel; they piped and wired the system
components together. Six additional trail-
ers provided office space for EPA, sam-
pling and analysis facilities, onsite
laboratories, ECO LOGIC process con-
trols, and a maintenance shop.
Storage tanks held nitrogen, propane,
hydrogen, oxygen, reformed gas, and pro-
cess residuals. Existing utility connections
provided electrical power and water. Re-
covery wells, installed in previously lo-
cated underground pools, provided
feedstock for the demonstration.
Technology Testing
ECO LOGIC designed the TDU/reactor
process to simultaneously treat 4 tons/
day of waste oil, 10 tons/day of wastewa-
ter, and 16 tons/day of soil, depending on
the nature of the contaminants, their de-
gree of chlorination, and their water con-
tent. The actual demonstration test treated
approximately 0.2 ton of waste oil, 2.9
tons of wastewater, and 1.1 tons of soil,
all contaminated with PCBs. On average,
the wastewater contained 3,757 ppm
PCBs; soil, 627 ppm; and oil, 254,000
-------
THERMAL
DESOfiPTlON
UNIT
35°C
Condensate
Gas
booster
Scrubber
water
make-up
and caustic
180°C
Stack gas
Boiler
^ \~\
Sfeam
-^
3 fc
<
Hydrocarbon
gas (5%)
Combustion
air
Figure 1. ECO LOGIC gas-phase chemical reduction process and thermal desorption unit
-------
To scrubber
Waste injection ports
Reactor steel wall
Fibreboard insulation
Refractory lining
Electric heating elements
Ceramic-coated central steel tube
To grit box
Figure 2. ECO LOGIC Process schematic diagram of the demonstrated unit.
ppm. The wastewater and waste oil were
spiked with PCE and the soil with HCB,
both tracer compounds to test Resource
Conservation and Recovery Act (RCRA)
destruction efficiencies.
ECO LOGIC first performed a series of
shakedown tests to establish optimum sys-
tem performance. Two liquid tests (Condi-
tions 1 and 3) and a soil test (Condition 2)
followed. Each test condition consisted of
three runs, except Condition 2, which con-
sisted of two runs. The demonstration also
included a 72-hr, continuous-operations
reliability test. The program maintained
optimal operating parameters while vary-
ing the media and contaminant concen-
trations in the feedstock. Table 1
summarizes the operating conditions for
each test.
EPA collected extensive samples from
points around the system components and
stored or logged important data on oper-
ating and utility usage. Laboratory analy-
ses provided information on the principal
process streams: desorbed soil, reactor
grit, scrubber residuals, reformed gas, and
boiler stack emissions. EPA evaluated
these data against established program
objectives to determine the capability of
the process to treat the designated waste.
Demonstration Results
Table 2 summarizes the results for the
wastewater and waste oil tests; Table 3,
the results for the soils tests. In general,
the reactor system met all the Condition 1
and 3 objectives except benzene emis-
sions. Condition 2 met all objectives ex-
cept DE for the tracer compound HCB.
The Technology Evaluation Report, avail-
able from NTIS, contains detailed data
from all three conditions. (See information
at back.)
Estimated Treatment Costs
The twelve cost categories established
for the SITE program formed the basis for
the detailed cost analysis. Costs relate to
the demonstration-size reactor unit, pro-
cessing an average of 2.2 kg/min, as op-
erated at the Middleground Landfill. Based
on an economic analysis contained within
the Application Analysis Reports, the esti-
mated costs for treating liquid wastes simi-
lar to those at the Bay City site range
from $1,670/ton (80% utilization rate) to
$2,000/ton (60% utilization rate). The most
important element affecting cost is labor
(52% of cost), followed by site preparation
(15%), supplies (12%), and start-up/mobi-
lization (12%). The estimated costs for
treating soils with the combined TDU/re-
actor system range from $500/ton (80%
utilization rate) to $630/ton (60% utiliza-
tion rate).
Conclusions
Based on the program objectives, the
demonstration confirmed the feasibility of
the gas-phase chemical reduction process
for treating PCBs and other chlorinated
organic compounds, for producing a fuel
gas from PCB-contaminated soil and liq-
uids, and for providing environmentally
acceptable air emissions.
Reactor System
In general, ECO LOGIC'S reactor sys-
tem effectively destroyed PCBs, reducing
them to lighter hydrocarbons. Stack emis-
sions generally met stringent regulatory
levels; however, benzene concentrations
in the stack gas and scrubber liquor re-
quired close monitoring. The scrubber li-
-------
quor required disposal as a RCRA waste
or recycling through the system for addi-
tional treatment.
TDU/Reactor System
The TDU did not perform to design
specifications. EPA categorized the TDU
test data as a system proof-of-concept
rather than as a comprehensive evalua-
tion of a fully developed unit. The test
data indicated that the TDU, as presently
configured, achieved desorption efficien-
cies at the expense of throughput. In ad-
dition, ECO LOGIC experienced material
handling problems with the TDU feed. The
combination of material handling problems
and inadequate organics desorption indi-
cated a need for further development. The
test data have identified system strength
and targeted areas that require improve-
ments.
Nevertheless, the demonstration did
show that ECO LOGIC'S TDU can desorb
PCB contaminants. Treatment of the TDU-
produced desorbed gas in the reactor pro-
duced stack emissions that generally met
stringent regulatory levels. The reformed
gas composition resembled coal-gas fuel;
the scrubber liquor required disposal as a
RCRA waste. In commercial operations,
this liquor could be recycled through the
system.
Table 1. Operating Conditions Summary
Component Parameter
TDU
Reactor
Scrubber
Recirculating fan
Vaporizer
Bath temperature
Dome temperature
Gas temperature
Pressure
Temperature
Pressure
Resident time
Inlet temperature
Outlet temperature
Water pH
Differential pressure
Flow rate
Gas pressure
Temperature
Pressure
Measure
(°C)
(°C)
(°C)
(in. H20)
(°C)
(in. H20)
(sec.)
(°C)
(°C)
(in. H20)
(dm)
(in. H20)
(°C)
(psi)
1
N/A
N/A
N/A
N/A
892
1.8
8
546
33
8.78
11.6
110
6.5
148.3
51.8
Condition
2
624
612
449
2.25
890
2.46
7.7
504
32
8.42
9.1
110
5.2
N/A
N/A
3
N/A
N/A
N/A
N/A
933
1.8
6.1
527
32
9.32
7.81
110
0.66
149
51.4
-------
Table 2. Summary of Results for Condition 1 (Wastewater), and Condition 3 (Waste Oil) Tests
Results
Objective
Demonstrate ORE for
PCBs: 99.9999%
Met
X
Not Met Range
99.9999% to
99.99999%
Conclusions
Good destruction.
Demonstrate DE for PCE: 99.99% X
Ensure no formation PCDD/PCDF X
Characterize PIC emissions X
Characterize HCI emissions X
Document MDNR air permit X
compliance
Characterize criteria air pollutants X
Document TSCA permit compliance X
Validate key cost assumptions X
Characterize effluents and residuals X
Determine suitability of reformed X
gases for reuse/resale
Demonstrate system reliability X
Develop mass balances X
Characterize scale-up parameters X
Validate CIMS
Document system operation X
99.99%
PCDD DE:
63.05% to 98.36%
PCDFDE:
99.91% to 99.98%
Benzene: 73 to
113pg/dscm
0.659 to 0.807
mg/dscm; 147.6 to
173.3 mg/hr;
99.96% removal
Benzene:
48.5ng/dscm
Throughput
reliability: 20 to
55% of design.
System availabil-
ity:24%
Good destruction.
No net PCDD/PCDF formation.
PICs characterized; benzene
emissions exceeded regulatory limit.
Acceptable emissions.
Air permit compliance documented;
benzene emissions exceeded MDNR
conditions.
Easily met permit conditions.
Met permit conditions.
Cost elements identified.
Organics destroyed; metals partitioned
to scrubber effluents; after further treat-
ment, scrubber liquor may be suitable
forPOTW.
Closely matched composition of other
commercial fuel gases.
Process reliability requires improvement.
Generally good closures, except for
certain metals.
Characterized.
May reflect data trends useful for
process control.
Data available for commercial scale-up.
-------
Table 3. Summary of Results for Condition 2 (Soil) Test
Objective
Demonstrate ORE for PCBs:
99.9999%
Demonstrate DE for HCB:
99.99%
Ensure no formation of
PCDD/PCDF
Characterize PIC emissions
Characterize HCI emissions
Met
X
X
X
X
X
Results
Not Met Range
99.9999%
72. 13 to 99.99%
PCDD DE:
42.5% to 99.45%
PCDFDE:
54.6% to 98.12%
0.68 mg/dscm;
150 mg/hr;
99.98% removal
Conclusions
Requirements met.
Inefficient desorption from soil in Run 1.
No net PCDD/PCDF formation.
Emissions characterized.
Acceptable emissions.
Document MDNR air permit X
compliance
Characterize criteria air pollutants X
Document TSCA permit compliance
Validate key cost assumptions X
Characterize effluents and residuals X
Determine suitability of reformed X
gases for reuse/resale
Demonstrate system reliability X
Develop mass balances X
Characterize scale-up parameters X
Validate CIMS
Throughput reliability:
4% to 21.2% of design.
System availability:24%
Air permit compliance documented.
Easily met permit conditions.
Not applicable.
Cost elements identified.
Organics destroyed; metals partitioned
to scrubber effluents; after further
treatment, scrubber liquor
may be suitable for POTW.
Closely matched composition of other
commercial fuel gases.
Process reliability requires improvement.
Generally good closures, except for
certain metals.
Characterized.
May reflect data trends useful for
process control.
Document system operation
Data available for commercial scale-up.
-------
The EPA Project Manager, Gordon M. Evans, is with the Risk Reduction Engineer-
ing Laboratory, U.S, Environmental Protection Agency, Cincinnati, OH 45268 (see
below).
This summary presents findings from two volumes:
"Technology Evaluation Report: ECO LOGIC International Gas-Phase Chemical
Reduction Process, Bay City, Ml," which discusses the results of the SITE
demonstration;
"Technology Evaluation Report: ECO LOGIC International Gas-Phase Chemical
Reduction Process, Bay City, Ml, Appendices."
Both volumes may be obtained by asking for Order No. PB95-100251, cost $52.00
(subject to change). These volumes will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
Two related reports, entitled "Applications Analysis Report: ECO LOGIC International
Gas-Phase Chemical Reduction Process, The Reactor System" and "Applications
Analysis Report: ECO LOGIC International Gas-Phase Chemical Reduction Pro-
cess, The Thermal Desorption Unit," discuss the applications of the demonstrated
technology.
The EPA Project Manager can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/540/SR-93/522
------- |