United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-01/056 November 2001
Project
Environmental Impacts of the
of Orimulsion®: Report to
Congress on 1 of the
Orimulsion Technology
Program
C. Andrew Miller, Kevin Dreher, Randall Wentsel, and Royal J. Nadeau
Orimulsion1, a bitumen-in-water emul-
sion produced in Venezuela, was evalu-
ated to provide a better understanding
of the potential environmental impacts
associated with its use as a fuel. A
series of pilot-scale tests were con-
ducted at the U.S. Environmental Pro-
tection Agency's Environmental
Research Center in Research Triangle
Park, NC, to provide data on emissions
of air pollutants from the combustion of
Orimulsion 100 (the original formulation),
Orimulsion 400 (a new formulation in-
troduced in 1998), and a No. 6 (residual)
fuel oil. These results, and results of
full-scale tests reported in the techni-
cal literature, were evaluated to deter-
mine the potential air pollutant
emissions and the ability of commer-
cially available pollution control tech-
nologies to adequately reduce those
emissions. Emissions of carbon mon-
oxide (CO), oxides of nitrogen (NOX),
sulfur dioxide (SO2), sulfur trioxide (SO3),
particulate matter (PM), and organic and
metal hazardous air pollutants (HAPs)
were measured from each of these
three fuels to provide a comparison
between the "new" fuel (Orimulsion) and
a fuel that has been commonly used in
the U.S. (No. 6 fuel oil). Results indicate
that CO, NOX, and PM emissions are
likely to be nearly the same as those
from the No. 6 fuel oil, that SO2 emis-
1 Orimulsion is a registered trademark of Bitumenes
Orinoco, S.A.
sions can increase if the Orimulsion
sulfur content is higher than that of the
fuel it replaces, that the particles gen-
erated by Orimulsion 100 and 400 are
likely to be smaller in diameter than
those generated by No. 6 fuel oil, and
that HAPs are also likely to be similar
to those from No. 6 fuel oil. Both the
full-scale results found in the literature
and the pilot-scale results measured at
EPA indicate that conventional air pol-
lution control technologies can effec-
tively reduce emissions to very low
levels, depending upon the type of tech-
nology used and the desired emission
levels. Because the bitumen in
Orimulsion is heavier than water and
due to the presence of a surfactant in
the fuel, spills of Orimulsion are likely
to be more difficult to contain and re-
cover than those of heavy fuel oil, es-
pecially in fresh water. Additional study
is needed before adequate containment
and response approaches can be de-
veloped. Little, if any, work has been
conducted by the fuel producer or the
scientific community to address the re-
maining spill-related issues.
This Project Summary was developed
by the National Risk Management Re-
search Laboratory's Air Pollution Pre-
vention and Control Division, Research
Triangle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
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Purpose and Approach
The purpose of the report is to address
the request by Congress that the U.S.
Environmental Protection Agency (EPA)
"provide better scientific data on the quali-
ties and characteristics of this product
[Orimulsion] and the potential environmen-
tal impact of its introduction" into com-
merce. To address this request, a team
led by EPA's National Risk Management
Research Laboratory (NRMRL) con-
ducted research to examine the potential
environmental impacts associated with the
use of Orimulsion as a fuel and prepared
the report. The EPA research team in-
cluded Office of Research and Develop-
ment (ORD) staff from NRMRL, the
National Health and Environmental Ef-
fects Research Laboratory (NHEERL), the
National Center for Environmental As-
sessment (NCEA), and from the Office of
Solid Waste and Emergency Response
(OSWER) staff from the Office of Emer-
gency and Remedial Response (OERR).
In response to reviews of Orimulsion
research needs by an interagency panel
and a panel of external technical experts,
EPA prepared an Orimulsion Technology
Assessment Plan (OTAP) to guide its re-
search efforts. The reviewers identified
the generation and control of air pollutant
emissions and the toxicity of those emis-
sions as the key areas of needed re-
search. Orimulsion spill response,
containment, and recovery, and the eco-
logical effects of such spills (particularly
in fresh water) were considered to be
less critical, and could be addressed as
needed by the appropriate party or par-
ties. The OTAP outlined a phased ap-
proach, with the need for subsequent
phases to be determined by any signifi-
cant questions identified during preced-
ing phases. The report describes the
efforts, results, and conclusions of Phase
1 of the OTAP.
The key questions addressed by the
report are:
•[Are the emissions from the combus-
tion of Orimulsion significantly differ-
ent from those from other fossil fuels,
and if so, how?
•[Can the emissions from the combus-
tion of Orimulsion be adequately con-
trolled using existing air pollution
control technologies? If not, are there
modifications to existing technologies
that can be made to adequately con-
trol emissions, or are new control
technologies required?
•Qfe the behavior of Orimulsion during
a spill significantly different than that
of other fossil fuels, and if so, how?
•Oft/hat gaps exist in understanding the
behavior of Orimulsion based on the
behavior of other fossil fuels and the
known properties of Orimulsion? Are
these gaps serious with respect to
understanding the potential environ-
mental impacts, and if so, what re-
search should be conducted to
address these gaps?
To address these questions, ORD staff
conducted a thorough literature review,
visited several full-scale power plants that
used Orimulsion as their primary fuel, con-
ducted pilot-scale combustion tests, tested
measures of pulmonary toxicity of PM
generated by Orimulsion combustion, and
carried out an independent review of an
assessment of environmental risks asso-
ciated with Orimulsion use. The report
discusses the methods and results of
these efforts and draws conclusions
based on those results.
Background
Orimulsion is a liquid fossil fuel con-
sisting of an emulsion of approximately
70% bitumen (a naturally occurring heavy
petroleum material) from the Orinoco re-
gion of Venezuela, approximately 30%
water, and a small amount of surfactant.
The fuel consists of small (8-24 urn diam-
eter) droplets of bitumen emulsified in
water and the surfactant. Orimulsion is
produced by Bitumenes Orinoco, S.A.
(Bitor), a subsidiary of the Venezuelan
national oil company Petroleos de Ven-
ezuela, S.A. (PDVSA), and derives its
name from the combination of "Orinoco"
and "emulsion."
In recent years, Orimulsion has been
proposed as a fuel to replace either coal
or heavy fuel oil in utility power plants
throughout the world. Orimulsion is cur-
rently being used as the primary fuel at
nine power plants in Canada, Denmark,
Italy, Japan, and Lithuania, representing
3,866 MW of electric power generating
capacity and approximately 7.5 million
tons of fuel consumption per year. To
date, no plant in the U.S. has used the
fuel for other than short-term testing.
Air Emissions
Available technical literature (24 refer-
ences describing air pollutant emissions
at 9 full-scale sites and 3 pilot-scale fa-
cilities) was reviewed to determine the
problems and issues believed to be most
important with respect to air pollutant
emissions and control and to evaluate
the levels of emissions experienced by
full-scale systems using Orimulsion. Table
1 summarizes data reported in the litera-
ture for Orimulsion and heavy fuel oil.
SO2 and PM data are for pollutant con-
centrations upstream of any control de-
vice.
The reports indicated that CO emis-
sions could be easily controlled by in-
creasing combustion air levels. In general,
the conventional techniques used to re-
duce NOX emissions from oil combustion
(staged combustion, reburning, selective
catalytic reduction) were reported to be
applicable to Orimulsion. CO and NOX
were dependent upon boiler oxygen (O2)
and the combustion system design, simi-
lar to other fossil fuels. SO2 concentra-
tions from Orimulsion [upstream of any
flue gas desulfurization (FGD)] were con-
sistent with SO2 concentrations from other
fuels with similar sulfur contents. The lit-
erature reported that conventional FGD
systems could remove up to 95% of SO2
generated by the combustion of
Orimulsion. This would result in controlled
emissions of approximately 125 ppm. Full-
scale results demonstrated that electro-
static precipitators can be used to control
PM emissions to a level similar to those
of other fossil fuels.
Emissions of HAPs were similar for both
Orimulsion and fuel oil. For both fuels,
volatile and semivolatile organic com-
pounds were found in very low quanti-
ties and would not be likely to be near
the 10-ton/year level specified in Title III
of the Clean Air Act Amendments of 1990.
Due to the elevated levels of metals in
Orimulsion, metal emissions were higher
than organics, with nickel (Ni) and vana-
dium (V) being found in the highest con-
centrations. Although V is not listed as a
HAP under Title III, it is of concern be-
cause of its potential for causing acute
pulmonary damage when inhaled. Ni con-
centrations in Orimulsion flue gas were
higher than those from heavy fuel oil, but
both iron and zinc concentrations were
higher in heavy fuel oil flue gases than in
those from Orimulsion. Processes have
been designed to allow recovery of Ni
and V in Orimulsion. At least two plants
are currently sending Orimulsion ash to
facilities for recovery of one or both met-
als, thereby reducing solid waste streams.
Data From EPA Pilot-scale
Tests
Two formulations of Orimulsion (one
commercially available and one discon-
tinued) and a No. 6 fuel oil were individu-
ally tested in a pilot-scale combustor at
EPA's Environmental Research Center to
allow direct comparison of emissions.
Concentrations of CO, nitrogen oxide
(NO), SO2, SO3, and PM were measured,
as were concentrations of volatile and
semivolatile organic compounds and met-
als. Measurements of emissions from the
different fuels were compared to deter-
mine any differences in the amount or
character of emissions. The tests were
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Table 1. Summary of air pollutant concentrations
reported in the literature for Orimulsion and heavy fuel
oil. (SO2 and PM values are upstream of any control
device.)
Pollutant
CO
N0x
S02<3>
S03<5)
PM<3>
PM size
Literature Data
Orimulsion0'
30-1 00 ppm<2>
(4 tests)
80-400 ppm
(1 0 tests)
2500 ppm
2-15 ppm
(6 tests)
1 60-350 mg/Nm3
(8 tests)
98-100%<10um
80-97% <1 urn
Heavy Fuel Oil
30-100 ppm
(4 tests)
1 80-420 ppm
(6 tests)
1 200 ppm<4>
4-1 2 ppm
(2 tests)
100-41 5 mg/Nm3
(4 tests)
75-87% <10um
45-51 %<1 urn
1 Most data reported in the literature are for Orimulsion
100, although there are several data points for
Orimulsion 400.
2 Concentrations of all pollutants are as measured and
are not corrected to account for differences in O2
concentration.
3 Concentrations are measured upstream of any control
device.
4 No SO2 values for fuel oil were reported in the
Orimulsion literature. The 1 200 ppm value is calculated
based on 2% sulfur in the fuel. SO2 concentrations are
strongly dependent upon the amount of sulfur in the fuel.
5 Measured using mini acid condensation sampling
(MACS) method.
conducted following NRMRL Quality As-
surance Level II procedures, which included
audits of measurement equipment and
reviews of data by outside organizations.
EPA's pilot-scale results were similar
to those reported in the literature in terms
of comparison of Orimulsion to heavy fuel
oil, with data showing little difference in
CO, NOX, or PM furnace exit concentra-
tions, and smaller particles for Orimulsion
than for heavy fuel oil. The pilot-scale
data differed most from the full-scale data
for NOX, but were not unreasonable given
the difference in combustor system de-
sign. The pilot-scale tests provided fur-
ther valuable confirmation of the similarity
between Orimulsion and heavy fuel oil,
and also generated samples for use in
pulmonary toxicity testing.
Toxicity Testing
NHEERL conducted tests measuring
the pulmonary toxicity in laboratory ani-
mals of PM generated by the combustion
of Orimulsion 100, Orimulsion 400, and
No. 6 fuel oil. Laboratory rats were ex-
posed by intratracheal instillation of dif-
ferent doses of PM from each of the fuels
burned in the NRMRL combustion tests,
as well as Arizona road dust (ARD) and a
saline solution. Five biomarkers of pul-
monary toxicity or injury [bronchial alveo-
lar fluid (BALF) neutrophil/mL, BALF
protein, albumin, lactate dehydrogenase
(LDH), and eosinophil/mL] were measured
at 24 hours post-exposure. Each sample
was ranked according to its lowest ob-
served effect level (LOEL) for each of the
five biomarkers. The relative toxicity
rankings for each biomarker were:
BALF protein: No. 6 fuel oil > Orimulsion
400 > Orimulsion 100 > ARD = Saline
albumin: No. 6 fuel oil > Orimulsion 100 >
Orimulsion 400 > ARD = Saline
LDH: Orimulsion 400 > Orimulsion 100 = No.
6 fuel oil =ARD = Saline
neutrophil: Orimulsion 100 = Orimulsion
400 = No. 6 fuel oil = ARD > Saline
eosinophil: Orimulsion 100 = Orimulsion
400 = No. 6 fuel oil > ARD > Saline
The conclusion drawn by the toxicity
tests is that, under the combustion condi-
tions employed in these studies, both
Orimulsion formulations generated PM
emissions that were capable of produc-
ing significant adverse acute pulmonary
toxicity. In addition, PM derived from the
combustion of Orimulsion 100 and
Orimulsion 400 was found to be very simi-
lar to No. 6 fuel oil fly ash particles in its
ability to induce acute pulmonary toxicity.
Different results are possible for PM from
full-scale units with different operating
conditions, for animals exposed via direct
inhalation rather than instillation, or for
health-compromised animals.
Spills
Orimulsion is considered to be a "non-
floating" oil and is classified as a "non-
petroleum oil" by EPA's Office of Solid
Waste and Emergency Response. Once
spilled, the bitumen fraction of Orimulsion
is likely to either sink or remain neutrally
buoyant, rather than forming a coherent
surface slick. Special equipment is re-
quired to effectively contain and recover
Orimulsion spills in saltwater environ-
ments, and such equipment is currently
used at shipping terminals where
Orimulsion is off-loaded.
Data gaps remain in understanding the
behavior and fate of Orimulsion spilled in
fresh water. However, as noted in the
OTAP, if Bitor does begin to develop U.S.
customers at a site accessible only by
fresh water, at a site near bodies of fresh
water, or at a site where fresh water can
be contaminated by a spill, even indi-
rectly, Bitor should be responsible for the
research to address the data gaps as
they have done for marine environments.
Such research does not fall under the
Congressional directive for this report and
should not be considered to be EPA's re-
sponsibility under that directive. However,
since EPA is responsible for responding
to spills in certain situations, the Agency
should continue to investigate Orimulsion
spill behavior and response as appropri-
ate. EPA, in collaboration with the U.S.
Coast Guard, has requested the National
Academy of Sciences (NAS) to conduct a
study on Orimulsion to evaluate what ad-
ditional information is required to effec-
tively respond to freshwater spills. EPA is
currently conducting smaller studies on
Orimulsion characteristics and on spill
behavior modeling and will address the
data gaps identified by the NAS, as ap-
propriate. EPA should remain aware of
any research conducted by others regard-
ing freshwater spills.
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Risk Assessment
The potential ecological risk associated
with the use of Orimulsion was evaluated
by a panel of independent reviewers cho-
sen by EPA, who examined the detailed
work carried out by Bitor to estimate the
ecological risk associated with a poten-
tial spill in the Tampa Bay, FL, marine
environment. The Bitor study compared a
hypothetical spill of Orimulsion 100 to a
hypothetical spill of an equal volume of
heavy fuel oil. The comparative assess-
ment examined transport and fate of both
fuels, including potential effects on shore-
lines and aquatic biota under a range of
different spill locations, seasonal varia-
tions, and wind and current conditions.
The independent reviewers agreed with
the major conclusion of the Bitor study
that a spill of Orimulsion 100 likely poses
a similar or lower risk to Tampa Bay biota
than does an equivalent spill volume of
No. 6 fuel oil. However, the reviewers
noted that parts of the assessment, such
as risk characterization, population mod-
eling, and impacts to benthic communi-
ties, were identified as assessment topics
that could be improved. The reviewers
felt that these improvements would en-
hance the Tampa Bay report, but did not
feel that the improvements would impact
the report's conclusions.
A study of cancer risk associated with air
emissions from the combustion of heavy
fuel oil in electric utility steam generating
units was used as the basis for comparing
cancer risks due to the use of Orimulsion
with those from the use of heavy fuel oil.
The original study evaluated the risk to
human health associated with exposure
to HAP emissions from electric utility
steam generating units and estimated that
0.4 additional incidences of cancer would
be caused by exposure to Ni emissions from
all 137 oil-fired plants in the U.S. This value
was considered to be a conservative esti-
mate of the potential cancer risk associ-
ated with the use of Orimulsion, based on
the Ni emissions from both fuels.
Potential Use of Orimulsion
Orimulsion can be used in applications
similar to coal or heavy fuel oil. Orimulsion
is readily used in plants designed to use
heavy fuel oil, due to the fuels' similar
handling and use characteristics, al-
though substantial changes to fuel stor-
age and handling equipment, air pollution
control systems, and boiler internal com-
ponents may be required. The difference
in fuel prices between fuel oil and coal
may also favor fuel oil as being more
likely to be replaced with Orimulsion. The
states with the highest fuel oil use are (in
order of amount used) Florida, New York,
Massachusetts, Connecticut, and Hawaii,
all of which are oil consumers and not oil
producers. They are also located on the
coast and may be more suitable markets
for Orimulsion than states with high coal
consumption.
Conclusions of the Report
•[Orimulsion is physically and chemi-
cally an emulsified heavy fuel oil with
elevated sulfur, V, and Ni content.
•[Emissions of air pollutants from
Orimulsion are not significantly dif-
ferent in character from those from
other fossil fuels. Orimulsion will, in
general, emit more pollutants than
natural gas, about the same as heavy
fuel oil, and less than pulverized coal.
These comparisons do not hold for
all cases and are based on emission
levels without air pollution control
systems.
•[Results from both full- and pilot-scale
tests indicate that emissions from the
combustion of Orimulsion can be ad-
equately controlled using commer-
cially available air pollution control
technologies.
•[Conversion of a plant to use Orimulsion
may require significant changes to
fuel supply and handling and air pol-
lution control equipment and modifi-
cations to boiler internal components.
•Qn general, Orimulsion generated PM
emissions that were capable of pro-
ducing significant adverse acute pul-
monary toxicity, very similar to the
No. 6 fuel oil tested. In all cases, PM
from both Orimulsion formulations
and the No. 6 fuel oil showed mea-
sures of toxicity greater than or equal
to either ARD or saline solution.
•CThe behavior of Orimulsion in a spill
is significantly different than that of
most other fossil fuels.
•CA review by an EPA-chosen expert
panel of a Bitor-funded ecological risk
assessment of a potential spill in the
Tampa Bay, FL, marine environment
agreed with the assessment's con-
clusion that a spill of Orimulsion 100
likely poses a similar or lower risk to
Tampa Bay biota than does an equiva-
lent spill volume of No. 6 fuel oil.
•CThe most likely use of Orimulsion in
the U.S. in the short term is as a
replacement for heavy fuel oil, due to
similarity in handling and combus-
tion properties, the price differential
between the two fuels, and the readi-
ness of plants using heavy fuel oil to
accept tanker shipments of
Orimulsion. These factors would in-
dicate that Orimulsion is most likely
to be used along the Atlantic and
Gulf coasts in the U.S.
• The major gaps in understanding
Orimulsion behavior are in freshwa-
ter spill response and effects. Further
work in this area should primarily be
the responsibility of the fuel's suppli-
ers and users and should not be con-
sidered as part of the Congressional
directive to provide improved scien-
tific information on the environmental
impacts of Orimulsion use. EPA
should continue to evaluate spill ef-
fects, behavior, and response, as
appropriate, in support of their legis-
lated responsibility for spill response.
Recommendations of the
Report
The following recommendations are
made with regard to Orimulsion behavior,
its potential environmental impacts, and
EPA's role in further studies:
1. Based on the results of Phase 1 of
the OTAP, it is not necessary for EPA
to proceed with Phases 2 and 3.
2. From the perspective of air pollutant
formation and control, Orimulsion
should be considered to be a heavy
fuel oil, albeit with some properties
that require special attention.
3. Studies of Orimulsion behavior in
freshwater spills are needed in the
event that Orimulsion is transported
along fresh waterways or used in situ-
ations where spills can reach fresh
water, even indirectly. This research
should evaluate the behavior and ef-
fects of Orimulsion under different
conditions (water density, presence
of silt or other solids, energy level of
waves) and should evaluate means
of containing and responding to spills.
Bitor or the end user should be re-
sponsible for the cost of any such
work that directly supports efforts to
market Orimulsion in the U.S. EPA
should continue to follow any work
conducted by others on the behavior
and fate of Orimulsion spills and
should conduct the research neces-
sary to support their legislated re-
sponsibility for spill response, outside
the scope of the Congressional di-
rective to provide improved scientific
information on the environmental im-
pacts of Orimulsion use.
4. Research recommended in a review
by an EPA-chosen panel of a Bitor-
funded ecological risk assessment
of a potential spill in the Tampa Bay,
FL, marine environment is consid-
ered to be the responsibility of Bitor.
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The EPA authors are C. Andrew Miller (also the EPA Project Officer, see
below), Kevin Dreher, National Health and Environmental Effects Re-
search Laboratory, Research Triangle Park, NC 27711; Randall Wentsel,
National Center for Environmental Assessment, Washington, DC 20460;
and Royal J. Nadeau, Environmental Response Team, Edison, NJ 08837.
The complete report, entitled "Environmental Impacts of the Use of
Orimulsion®; Report to Congress on Phase 1 of the Orimulsion Technology
Assessment Program; Volume 1: Executive Summary, Report, and Appen-
dix A," and "Volume 2: Appendices B-H," will be available at http://
www.epa.gov/ORD/NRMRL/Pubs or from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: (703) 605-6000
(800) 553-6847 (U.S. only)
as
• Volume 1: Order No. PB2002-109039; Cost: $44.00, subject to change,
and
• Volume 2: Order No. PB2002-109040; Cost: $44.00, subject to change.
The EPA Project Officer can be contacted at:
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
United StatesD
Environmental Protection Agency D
CenterforEnvironmental Research InformationD
Cincinnati, OH 45268D
PRESORTED STANDARDD
POSTAGES FEES PAIDD
EPAD
PERMIT No. G-35D
Official Business
Penalty for Private Use
$300
EPA/600/SR-01/056
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