United States
                      Environmental Protection
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-
                        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).

                        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

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.

  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
   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.

  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-


                          200       400       600        800       1000       1200
                                            Hours on Oil
Figure 1. Bypass filter vs. control samples CAT 3512, engine No. 5.
                       200      400      600     800     1000     1200     1400
                                             Hours on Oil
Figure 2. Bypass filter vs. control samples CAT 3516, engine No. 8.





        O   1.5


                 ,''/'  ^ 95% Confidence
               0       50

Figure 3. 1.5% all: fuel blend engine, Volvo MD11C.

100      150      200      250      300     350
            Hours on Oil
                     200  400   600    800   1000  1200   1400  1600  1800  2000
                                            Hours on Oil
Figure 4. Control extended to zero TBN engine, Volvo MD11C.

  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



    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

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