United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-96/092 September 1996
AEPA Project Summary
Waste Oil Reduction for
Diesel Engines
Todd Sigaty, Carl Reller, and Daniel Middaugh
This project reduced waste oil from
diesel engines at remote sites in Alaska
by extending oil change intervals us-
ing bypass filters and a closed-loop
reblending process in connection with
portable field monitors and laboratory
analysis. Incidents of normal and ab-
normal oil degradation were recorded
and correlated between field and labo-
ratory tests. A quality assurance pro-
gram evaluated data precision and ac-
curacy.
Waste oil from diesel engines repre-
sents the greatest environmental health
problem in Alaska, especially in remote
areas where disposal/recycling options
are nonexistent. Results of this project
showed that small, isolated communi-
ties can reduce the amount of waste oil
generated at the source with techniques
that are easy to implement and inex-
pensive. However, they depend prima-
rily on operator interest in closely moni-
toring the engine because degradation
levels need to be determined individu-
ally for each engine and oil type by
establishing baseline data.
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory, Cincinnati, OH,
to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
This study was a cooperative effort be-
tween EPA's National Risk Management
Research Laboratory (NRMRL) and the
Alaska Health Project (AHP), the central
site of the project. The AHP, located in
Anchorage, is a nonprofit organization of-
fering technical assistance on pollution
prevention and waste reduction. The goal
of this project was to test different tech-
nologies to reduce waste oil at remote
sites in Alaska.
The generation of energy is critical to
remote villages, marine vessels and mili-
tary bases throughout Alaska. The use of
diesel generators to provide that energy
results in large quantities of used oil, part
of the more than one billion gallons of
waste oil generated annually in the U.S.
The U.S. Environmental Protection
Agency (EPA) is concerned about the
quantity of waste oil improperly disposed
of each year because of its threat to the
environment and its cost to remediate.
Carefully managed, used oil retains its
economic value, but many small commu-
nities have neither the experience nor the
knowledge to evaluate the condition of
used oil or to determine a reasonable
means of recycling. Consequently, much
of the accumulated used oil is transported
many miles at substantial cost, and indis-
criminate dumping is common. Current
filtration technology may be able to pro-
cess used oil on site, providing a re-
cycled oil that meets specifications for
burning. Objectives for this project were
to determine (1) whether engine
manufacturer's recommendations for oil
change intervals (OCIs) could be in-
creased with field and laboratory mea-
surements of oil degradation; (2) whether
bypass filters are effective in extending
oil drain intervals; (3) whether the
closed-loop process is efficient and af-
fordable in eliminating waste oil; and (4)
whether these technologies can be easily
implemented by small, isolated communi-
Printedon Recycled Paper
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ties. The project also evaluated whether
technologies for extending oil life would
concentrate polynuclear aromatic hydro-
carbons (PAHs) at levels hazardous to
the health of oil handlers.
Procedure
The sites selected for this project were
stationary electric generating plants located
in rural areas ranging from the Arctic north,
through the Aleutian Islands, to the tem-
perate rain forests of Southeastern Alaska.
Other participants were a marine vessel
and a federal hydroelectric facility. Phase
I—extension of oil change intervals using
analysis alone—was conducted over an
11-month period at 13 Alaskan sites on
20 diesel engines ranging from 23 to 3,000
hp. Participants were asked to gradually
extend OCI based on field monitoring and
laboratory analysis alone.
In Phase II—extension of OCls through
the use of bypass filters—data was com-
plied from nine diesel engines at four sites.
Filtration is defined for this project as the
physical separation of liquids and solids
by means of centrifuges and media filters,
the two technologies commonly used in
bypass filters. Oil is commonly filtered be-
tween oil pump and engine by diverting
100% of the oil through a "full flow" filter
able to remove large particles (greater
than 20 microns). Full flow filters are inef-
ficient at removing liquids (such as water,
unbumed fuel or acids) and small metal
contaminants below 20 urn. Bypass filters
remove particles in the below-20-micron
range by intercepting about 10% of the
main flow of oil. The following filter sys-
tems were selected for this project based
on product quality and information, expe-
rience and cost: Gulf Coast, Spinner,
Purifiner, Harvard and Power Plus. Used
oil samples were taken from the engines
as often as every two days and tested by
the engine operator onsite and by the
project manager at the AHP office. To
monitor oil quality in the field a portable
battery-powered comparative dielectric
analyzer (CDA) was used. This equipment
determines the deterioration in motor oil
from continued use. By measuring any
deviation of the dielectric constant between
fresh and used oil, it indicates the overall
condition of the oil and helps determine
the optima) oil change interval. For this
project, the LubriSensor Model N1-2B was
selected based on its cost, usability and
documentation ability. After each sample
was tested in the field it was sent to Ana-
lysts Laboratory in Oakland, CA, for analy-
sis of the physical and chemical proper-
ties of the oil. This lab was chosen after a
national search on the basis of its quality
manuals, experience and commercial avail-
ability. For this project, Analysts tested
each sample for 21 metals and the total
base number (TBN). TBN is an indicator
of oil buffering quality, i.e., the quantity of
hydrochloric acid, expressed in terms of
the equivalent number of milligrams of
potassium hydroxide required to neutral-
ize all the basic constituents present in a
one-gram sample of oil. The TBN indi-
cates relative change in oil regardless of
color or other properties. This project chose
to analyze TBN and CDA as the best
indicators of oil quality. Lab results were
sent to AHP and then to the engine op-
erator. With every fifth used oil sample, a
quality control sample was sent to the lab.
In Phase III—the elimination of waste
oil through reblending and recycling—a
closed-loop process was used on a sta-
tionary engine and a marine engine at two
different sites. The closed-loop process is
one in which the oil is removed from the
engine at a set rate and blended in the
fuel tank at a varied ratio of oil to fuel. In
addition to eliminating the need to dis-
pose of v/aste oil, the quality of the fuel is
increased. For this project, the Power Plus
Smart Tank Model ED3500S was selected
for the stationary engine; the Volvo MD11C
marine engine used its own blending sys-
tem constructed onsite. Oil was removed
at the rate of 1.3 oz/engine hr and blended
in the fuel tank at 2% oil : fuel. This
removal rate uses the same amount of oil
as changing the oil once every 150 hr.
Upon good analysis, the removal rate was
reduced by 50% to .65 oz/hr, and the
blend to 1% oil : fuel, a removal rate
equal to changing the oil once every 300
hr.
During the project, the methods or inde-
pendent variables were oil analysis and
filtration systems. Dependent variables
were oil change intervals and cost. Re-
sults from samples collected at each site
were compiled on data sheets and en-
tered into a database. To ensure accu-
racy, the data were entered twice by two
separate individuals. Each data set was
cross checked for discrepancies. All mea-
surements, data gathering equipment and
data generation activities were routinely
assessed for precision, accuracy, com-
pleteness and detection limits.
Results; and Discussion
Results of the data were plotted on
graphs; several examples are shown here.
Figure 1 shows the CDA readings against
engine hours on oil for each of the bypass
filters on engine No. 5. A higher CDA
rating can be an indication of possible oil
contamination. The control plot is an ex-
tension of oil drain interval without a by-
pass filter. On this engine the control
samples had lower CDA readings than
samples from the Spinner filter. The
samples from the Purifiner filter had a
lower CDA reading than the Spinner or
control samples. All samples on this en-
gine were able to extend their OCI to over
800 hr without any CDA readings indicat-
ing oil contamination. Figure 2 shows CDA
readings against engine hours for the con-
trol used-oil samples and the Gulf Coast
used-oil samples on engine No. 8. A higher
CDA reading can be an indication of pos-
sible oil contamination. The control plot is
an extension of oil drain interval without a
bypass filter. This figure shows that on
this engine the control samples had lower
CDA readings than the Gulf Coast
samples, but that both sets of used-oil
samples were able to be extended to over
1200 hr without any CDA readings indi-
cating oil contamination. Figure 3 shows
the CDA readings against engine hours
for the control used oil samples and the
1.5% oil: fuel blend samples on the Volvo
MD11C engine within a 95% confidence
level. A higher CDA reading can be an
indication of possible oil contamination.
The control plot is an -extension of oil
drain interval without a by-pass filter. The
blend is a closed-loop process where used
oil is blended with incoming fuel. This
figure shows lower CDA ratings than the
control samples on this engine. The blend
samples were extended to over 200 hr
without CDA readings indicating any oil
contamination. (Manufacturer's recommen-
dation is 50 hr.) The control samples were
able to extend the oil to over 350 hr but
had CDA readings indicating possible oil
contamination. Figure 4 plots the com-
plete range of data points and extends
the data to the point where TBN level
would reach zero on the Volvo MD11C
engine. The figure shows a direct relation-
ship between CDA and TBN readings with
a 95% confidence level extended to over
1000 hr. This ability to predict the TBN
level aids the engine operator because
lab analyses take time and are costly.
Conclusions
This study focused on answering the
objectives stated in the Introduction. The
study finds that:
1. Oil change intervals can be extended
beyond engine manufacturers' warranty
recommendations without oil degrada-
tion. To ensure protection of the engine
while extending the OCI, field monitor-
ing of oil condition is recommended.
CDA data collection is easy, inexpen-
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o>
T3
o
200 400 600 800 1000 1200
Hours on Oil
Figure 1. Bypass filter vs. control samples CAT 3512, engine No. 5.
0.0
200 400 600 800 1000 1200 1400
Hours on Oil
Figure 2. Bypass filter vs. control samples CAT 3516, engine No. 8.
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3.0
2.5
2.0
I
8
oc
O 1.5
1.0
0.5
,''/' ^ 95% Confidence
0 50
Figure 3. 1.5% all: fuel blend engine, Volvo MD11C.
10
100 150 200 250 300 350
Hours on Oil
4|
z
&
I
200 400 600 800 1000 1200 1400 1600 1800 2000
Hours on Oil
Figure 4. Control extended to zero TBN engine, Volvo MD11C.
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sive and a good indicator of oil degra-
dation. There is a consistent relation
between CDA readings and TBN levels
in measuring oil degradation. However,
each engine and situation is unique.
Therefore, OCI extensions based on
CDA response should be correlated with
laboratory analysis for each engine, lu-
bricating oil and fuel type. The prob-
ability of oil decreasing TBN increases
between 800-2000 hr and at a CDA
reading of 3.0-6.0 for the engines tested
in this study.
2. Oil samples from stationary diesel en-
gines that used bypass filters showed
no less oil contamination than control
samples. Other studies have revealed
that oil change intervals can be ex-
tended when using bypass filters, but
they had no control data. The Power
Plus used-oil blend unit limits oil degra-
dation and eliminates waste oil for sta-
tionary diesel engines. The Power Plus
unit is efficient, effective and afford-
able. Based on a 5,000 hr/yr opera-
tional period, engines at one site
(Unalaska) saved over 2,000 gal/yr. One
engine at Unalaska, and the engine at
Seward, eliminated waste oil while us-
ing the Power Plus re-blend technol-
ogy. Based on a 5,000 hr/yr opera-
tional period, engines at one site
(Unalaska) saved over 2,000 gal/yr of
lubricating oil.
3. Small isolated communities can reduce
the amount of waste oil they generate.
However, the ability to do so is based
primarily on operator interest and de-
sire to closely monitor the engine. This
increased attention is needed because
degradation levels need to be deter-
mined individually for each engine and
oil by establishing baseline data.
The study further found no significant
health hazard from PAHs in the used oil
sampled resulting from oil exchange inter-
vals or burning used oil.
The full report was submitted in partial
fulfillment of Contract Number
CR-817011-01-0 by the Alaska Health
Project under the sponsorship of the U.S.
Environmental Protection Agency.
•&U.S. GOVERNMENT PRINTING OFFICE: 1996 - 750-001/41051
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Todd Slgaty, Cart Reller, and Daniel Middaugh are with Alaska Health Project,
Anchorage, AK 99501.
Paul Randall is the EPA Project Officer (see below).
The complete report, entitled "Waste Oil Reduction for Diesel Engines," (Order No.
PB96-196779; Cost: $28.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
National Risk Management Research 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/600/SR-96/092
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