WASTE OIL MANAGEMENT - A STATUS REVIEW
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WASTE OIL MANAGEMENT - A STATUS REVIEW*
by
Peter B. Lederman, Ph.D.
Industrial Waste Treatment
Research Laboratory
Nat'l. Environmental Research
Center, U.S.E.P.A.
Edison, N.J.
Norman J. Weinstein, Ph.D.
Recon Systems, Inc.
Princeton, N.J.
The U.S. Environmental Protection Agency (EPA) has been concerned
with waste oil for 5 years. The Agency's program for the proper man-
agement of waste oils has been under the direction of the National
Environmental Research Center-Cincinnati's Industrial Waste Treatment
Research Laboratory and its predecessors. Recon Systems has been under
contract to develop an input-output model for waste oil and evaluate
waste oil processes with respect to their environmental impact. We
would like to take this opportunity to review that program for you.
Finally, we will indicate where we believe the Agency will continue to
play a role in the management of waste oils.
Program Origin
EPA's concern with waste oil originated from reports that these oils
found their way into watercourses. The Agency's initial concern was sup-
ported by the Congress in the Water Quality Improvement Act of 1970.
This was followed by a mandate from Congress, in Public Law 92"500 (the
1972 Federal Water Pollution Control Act Amendments), that by April of
137^ a report be sent to the Congress indicating the state of waste oil
management.
-For presentation before the API-automotive Industry Forum, Detroit,
Michigan, January 31,
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Initially, the Agency's concern was with the water pollution aspects
of waste oil management. Within the past 18 months, the conservation of
natural resources has taken on as important a role in the management of
waste oil as has its control from the water quality aspect. Thus, the
current EPA program emphasizes resource recovery with environmental con-
trol .
How Much Waste Oil?
There are two primary sources of waste oil: the first is crankcase
oil and the second, industrial oil. In addition to that, oil is re-
covered from spills, tank cleanings, ballast water, and a variety of
miscellaneous activities indigenous to an industrial state. Data on the
amount of waste oil are extremely difficult to accumulate.
Sales of new oils in the United States total about 2.5 billion gal-
(D
Ions annually. As seen in Figure 1 and Table 1, these are split be-
tween crankcase and industrial oils. The industrial oil is often re-
cycled internally. The amount of industrial oil available in the open
market for reuse is not well defined.- A recent survey in Pittsburgh
suggests that perhaps 200 to 300 million gallons of crankcase and Indus-
(3)
trial oil are available in the open market for recycle. Additionally,
a considerable amound of waste oil from industrial sources is re-refined
on a custom basis if it is not recycled within the plant itself.
Of the 1.2 billion gallons of crankcase oil sold in the United States,
(M
the API has estimated that about 68% leaves car engines as waste oil.
-Reuse and/or recycling as used in this paper refer to use as a feed
stock by re-refiners, a fuel, or other environmentally sound uses
which replace virgin oil.
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A more detailed breakdown of how oil sold is converted to waste oil,
based on the recent Recon Systems study in Pittsburgh, is summarized in
Table 2. Thus, about 800 million gallons annually should be available
(D
for recycle, as shown in Figure 2. A number of surveys have been
conducted to determine the availability of waste crankcase oils for re-
cycle. Results of these surveys are summarized in Table 3- It is quite
evident that there is a wide discrepancy between what should be available
and what is thought to be available. The worci "thought" is used because
surveys of this kind are plagued by large confidence intervals. They
depend on the memories of gas station owners who will often report the
most recent data, if any at all. These data must be extrapolated to
cover all stations. !
Data for waste oil generation at automotive service centers» based
on waste oil generation factors, are detailed in Table k. Commercial
fleets generate another 100 million gallons per year. Missing one
major user (e.g. a city or state garage, or a major bus fleet) in the
survey can result in a significant error. Nevertheless, it is quite
evident that at best, if all the lube oil were sold for automotive use,
50% of the crankcase oil that should be available for recycle is avail-
able. If one is then to believe the accumulation versus pick-up results,
as determined in the State of Maryland survey, only 50% of what is avail-
able is picked up and is actually recycled.
Thus, one can establish that 200 to 400 million gallons of crankcase
oil are recycled annually. Yet only 100 million gallons are actually re-
refined (operating throughput), as determined by personnel from the
Industrial Waste Treatment Research Laboratory in a survey made in the
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spring of 1973 (Table 5).
The remaining oil that Is unaccounted for ends up in a number of
places. First, much is burned as a mixture with No. k or 6 oil in indus-
trial furnaces. Although this practice is energy conserving, it does
mean that more lead is emitted into the atmosphere. If all the waste
crankcase oil were burned, and $Q% of the lead ends up in the stack gas,
somewhere between 7 and 15 thousand tons of lead would be emitted into
the atmosphere annually. This is only a small fraction of the lead
emitted from automobile exhausts (k to 8%). It represents not only the
addition of lead to the atmosphere, but also a loss of a natural resource.
Lead is found in waste oils at up to one percent concentration as shown
CO
in typical analysis (Table 6 ), and in waste oil distillation residue
in concentrations up to 10%. Thus, the lead in the waste oil is as, or
more, concentrated than that in many ores mined commercially. The
Agency is working with industry to find a method to recover this lead.
Road oiling to keep down the dust, particularly in farming areas,
uses significant quantities of waste oil in season. Waste oil has been
cheaper than a specially compounded o\1 , and thus is favored from a
short range economic point of view. However, the waste oil leaves the
road quickly, potentially polluting watercourses and not having a
(8)
lasting effect on preventing dust. Thus, both from an environmental
and a resource point of view, other methods of dust control will probably
have to be found.
Some waste oil is utilized in hot road asphalt. This may be either
in its raw waste form or as a distillate cut from the waste oil. Where
specifications permit, this seems to be an acceptable utilization of
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waste crankcase oil. True, there are numerous other uses for crankcase
oil, but these are the major ones. We have not mentioned the do-it-
yourself changer who probably dumps his oil either into the sewer system
or on a landfill. This oil is, of course, lost.
Under present economic conditions we believe that any oil collected
is utilized. Contrary to one year ago: collectors cannot afford to
dump oi1.
Waste Oil Processes
The major re-refining process in use today, as seen from the IWTRL
survey, is acid/clay treatment. Another process used in the United
States is vacuum distillation followed by clay treating. This may be
preceeded by a caustic treat. Detailed discussions of these, as well
as a solvent extraction process are presented in the appendix.
Acid/clay treatment can produce a good lube stock. As practiced
in this country, however, acid consumption and tar yields are high.
The former results in poor economics; the latter produces a disposal
problem. As discussed later, both these problems seem to be solved in
German practice.
Although solvent extraction is,old in the art of lube oil manu-
facture, it has not, in the past, found favor with waste oil reprocessors,
High solvent-to-oil ratios result in high operating costs. Con-
tinuous operation requires skilled operating personnel. Finally, acid
and clay treatment are not fully eliminated. Several firms have
developed solvent extraction processes at pilot plant scale. Only the
Institut Francais du Petrole (IFP) has commercialized the process in
Europe.
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Agency's Program
EPA has had a multi-faceted program in waste oil management. To
date, approximately $1.2 million have been spent on waste oil management
studies. Table 7 indicates that most of this money has been spent to
develop new process technology. Other significant expenditures have
been made for development of institutional programs and evaluation of
existing technology and methodology.
In process development, the Agency has funded a major program to
develop a non-polluting process for re-refining and recovering waste
oils for use as diesel fuel and/or lubricants. The major emphasis in
this program has been the development of a distillation process preceded
by a pre-treatment process or followed by hydrotreating to develop a
stable lubricating oil. The first part of this study was completed in
1971 and the second part will be completed in 197**- We anticipate that,
eventually, a hydrotreating process will be demonstrated for the pro-
duction of lubricating oils. This particular program is being carried
out by the National Oil Recovery Corporation (NORCO). A conceptual
process using hydrotreating is discussed in the appendix.
In connection with that program, a bottoms product that is high
in lead (10% lead and 25% solids) is produced. The Agency, working in
concert wi.th NORCO and NL Industries, is demonstrating that this product
can be successfully recycled into a lead reclaiming operation for its
lead and heating value.
In one of its earlier efforts, the Agency supported work at
(9)
Villanova University to prove out caustic treatment of waste oils.
This process is being used at Blackwood Carbon Products, Inc. in
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Blackwood, N.J., as well as by several commercial re-refiners.
The Agency also sponsored some work by the GCA Corporation on the
(10)
enhancement of incinerator operation by adding waste crankcase oil.
This study was completed successfully, and a report on it is available.
GCA recommended that a demonstration be initiated as a result of their
findings that the addition of waste crankcase oil improved incineration
operation and produced a better, more sterile, incinerator effluent.
One of the major problems that has been plaguing industry has been
the disposal of the sludge remainders from re-refining. Landfill ing of
petroleum and acid sludges is coming more and more under fire. There
are special situations where the sludges end up in road tars or roofing
felts or other products, but these markets, too, are very limited.
Therefore, in addition to its program at NL Industries, the Agency is
sponsoring work to develop acceptable means of disposing of the re-
refining sludges. This work is going on in the State of Maryland and
at Rutgers University. Results from these studies should be available
within the next year.
Probably as critical, if not more critical, than the re-refining
of the waste oils is their collection. To determine the feasibility
of setting up a statewide collection and re-refining system, the Agency
in 1972, awarded a grant to the State of Maryland. Work under this
grant has been completed, and part of the work will be reported very
(7)
shortly. Environmental Quality Systems, Inc. has developed for the
State of Maryland, as a result of the grant, a waste oil collection
model. They can, using collectors now available, collect all the waste
oil in the State at an average cost of 3
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to a sales value of 4< and more per gallon. The model can easily be
adapted to other States or regions. The second phase of the report is
a preliminary process design study for a plant to handle all waste oils
generated within the State of Maryland.
A study to develop a recycling system for major Federal facilities,
(11)
such as large military bases, has been completed by Teknekron Corporation.
They recommend that a collection system be established on a Federal
facility and that re-refining to lube oil be done by an industrial re-
refiner on a contract basis. This is, of course, similar to what is
done for industry when their oils are custom re-refined.
GCA Corporation has been evaluating the burning of waste oil as a
fuel. The study is still under way and is being complemented by work
being done under the sponsorship of the API with Hawiian Electric Corp-
orat ion.
In the evaluation area, the Agency has contracts with a number of
groups to obtain data on waste oil generation, waste oil utilization,
and the engineering evaluation of current waste oil re-refining processes.
These studies will all be incorporated into the report, which is due to
the Congress in April of this year.
What Are Others Doing?
Probably the most significant re-refining and recycling movement
is that in Germany. The Germans, historically, have re-refined waste
oil. Currently, of their mi 11ion-ton-per-year lubricating oil require-
ments, 200 to 250 thousand tons are supplied by re-refined oil. This
oil competes on the market with virgin oil. The collection of the oil
is regulated by law and is supported by a tax on the sale of oil,
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which is then returned to the re-refiner (or burner of waste oil) who
passes on most of the subvention to the collector. Under the law, all
waste oil must be collected. However, do-it-yourselfers' crankcase
wastes are probably not collected in Europe just as in the United States.
The collectors are licensed—as are the reprocessers or burners. Oil is
imported into Germany from other countries, re-refined, and sold back in
those countries.
The German re-refining industry is basically an acid/clay industry.
However, utilization of high-shear mixers and pre-treatment with a co-
agulant reduces the acid and clay treats to about five percent.
In Berlin acid sludges are landfilled, according to the Scientific
Director of the Department of Health and the Environment; the acid
sludges degrade rapidly on the fills.
The French (IFP) have, as has been well advertised, a propane
extraction process. Unfortunately, this process still requires acid
and clay treatment. It is currently being utilized to produce first-
rate lubricating oils at the Viscolube plant in Milan, Italy. Two
other plants, utilizing the propane extraction process followed by
hydrofining, are being built in Yugoslavia and Sardinia by IFP. Both
the Italians and the French encourage the recycling of oil, giving re-
refiners tax advantages; these are not as favorable, however, as those
found in Germany. ;
Where to From Here?
It is obvious to everyone that waste crankcase oil represents an
opportunity for resource conservation as well as reduction of environ-
mental pollution. Short run it would appear attractive to merely blend
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the collected waste oil with fuel and burn it. Someone has burned it
straight when no ther fuel was available (with extreme burner plugging
(12)
problems). The policy of incinerating, with heat recovery, of waste
oils does not take into account, however, the worth of the oils as
lubricants. This factor must be considered.
Crudes to produce lubricants have always been more valuable than
crudes used only for energy production. One could expect, although
there are no hard figures, that lube crudes will be in even tighter
(2)
supply than fuel crudes. It probably behooves us to maximize the
lubricating values of waste oils. It would appear that this would be
economically attractive in the long range. In order to do this we must
continue to develop non-polluting re-refining processes. It will also
be necessary for the industry to develop a sound approach. This means
that the industry must share in the development of these processes and
develop plants of sufficient size to support newer re-refining processes.
This support must be both in terms of economy of scale and In technological
sophistication which comes with larger size plants.
In order for the industry to compete, it is necessary that it pro-
duce a first class product. It has done so in the past and continues to
do so on a selective basis. The guiding light is there; in Germany re-
refined lube oils compete with the quality lubricating market. Small
quantities of re-refined oil compete in the United States. The United
States industry can do the same on a large scale.
In the end there will be several ways of managing the waste lubri-
cating oils industry: lube production, energy recovery, admixing into
asphalts, and others. Local conditions will dictate the method of choice.
10
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APPENDIX
Current Waste Oil
Re-refining Processes
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ACID/CLAY TREATMENT
The process scheme for the typical acid/clay re-refining of waste
automotive oils is shown in Figure 3- The process for diesel engine waste
oils differs only in process condition details.
Incoming materials are unloaded into a partially submerged tank di-
rectly from the collection trucks. This receiving tank must be fitted
with grids and screens to remove the debris which is normally found in the
waste materials. The recommended tank would be large enough to accept the
entire truck load and permit any free water to settle. The oil is then
decanted and transferred to feed storate tanks, and the water layer to a
skimmer and then to wastewater disposal. The proper handling of the raw
material is extremely important to a smooth operating facility.
A typical analysis of oil in the storage tanks would be:
Water J>.5% by volume
Naphtha 7.0% by volume
Oil, etc. 89.5% by volume
More detailed analyses are presented in Tables 1 and 2. The feed is pumped
through a steam heat exchanger to the flash dehydrator which operates at
300°F and atmospheric pressure. The steam/oil overhead is condensed and
separated; the oil to light end storage to be used for fuel, and the water
to the wastewater disposal system.
The dehydrated oil is sometimes stripped prior to acid treating, but
more often it is pumped directly to dry oil tanks, where it is stored and
cooled. It can be stored for 2 to k days before it picks up appreciable
moisture which tends to increase acid requirements during the following
step. After 1*8 hours storage the oil temperature has dropped to approxi-
mately 100°F.
Dry oil is pumped to one of several acid treating units. These units
are steam jacketed and are agitated with plant air. Four to six volume
percent of 93% sulfuric acid is added to the reactor where the temperature
is maintained at about 100°F. The oxidized products contained in the oil
are usually coagulated within 2k hours, but up to kB hours may be be re-
quired depending on the raw material. The acid sludge, containing oil
contaminants and ash, separates from the oil and is drawn off from the re-
actor bottom. Acid sludge disposal, which usually is done in landfills or
lagoons, is one of the most critical problems in this process.
The acid treated dehydrated oil is then transferred to the steam
stripping-clay treating operation. The clay treater is equipped with over-
head condensing equipment and direct fired heater through which the oil is
A-l
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circulated. The capacity of the clay treater is usually on the order to
5,000 to 10,000 gallons. It is equipped with a sparger for direct intro-
duction of steam.
The temperature of the batch is brought up to 550-600°F by circulat-
ing through the heater after the batch has been transferred. Simultane-
ously, live steam is introduced into the batch. The purpose of this
stripping operation is to remove the remaining light fuel fractions and
any mercaptans which may be present. This operation normally takes 12-15
hours to complete. The steam-stripped materials are condensed, and the
oil separated from the water. The water fraction is treated through the
wastewater disposal system and the oil fraction used as plant fuel.
The heat is discontinued and part of the fuel oil is diverted to the
clay slurry tank. The oil temperature is permitted to drop to approxi-
mately 1*00°F. The clay, often a 50% mixture of activated clay and dia-
tomaceous earth (200-250 mesh), is mixed into the circulating oil. The
clay dose is approximately O.^t pounds per gallon of oil. The clay removes
color bodies as well as colloidal carbon by adsorption.
The hot air (250-350°F) containing the clay is filtered through a
plate and frame filter press, sometimes followed by a second filter in
series. The clarified oil is then stored either prior to or after having
the necessary additives blended into the stock.
The filter cake, a mixture of clay, impurities, and oil, is uneconom-
ical to separate and recover after filtration in small plants. It must
therefore be discarded, usually by landfill. This is becoming increasing-
ly difficult to do, as discussed in a later section of this report. Paper,
which is often used as a filter medium in the plate and flame press, is
discarded with the cake.
Odors can be a problem with acid/clay re-refining. These may emanate
from storage tanks, processing vessels, wastewater treatment facilities,
acid sludge, and oil spills. In some re-refining operations, odors can be
controlled adequately by sealing open vessels and tanks, good housekeeping,
and by venting process vessels to furnaces where vapors are burned with
the normal fuel. Other plants have resorted to control methods such as
caustic scrubbers.
The wastewater system varies from plant to plant, depending on cooling
water and vacuum facilities, water runoff problems, land availability, wa-
ter contamination of feedstocks, governmental regulations, and availability
of a local sewage plant. A typical installation includes an API separator
with oil skimming, pH control, some water recycle, and discharge to a
sewage plant. Sewage plants will normally accept water with oil contents
up to about 100 ppm, a quality level relatively easy to meet. Little data
is available on other wastewater characteristics.
A-2
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Overall lube stock yields for acid/clay treatment have been reported
from k$ to 75%- These obviously depend upon operating conditions and
feed composition, with water, sludge, ash, and gasoline contents being
most critical. For the type of feed reported herein (3-51 H20, 7.0%
maphtha), greater than 70% yield is possible with good operation.
The oil produced by the acid/clay process can be considered a solvent
neutral blending stock, with properties approximating an SAE 20 lubricat-
ing oil. SUS (Saybolt Universal Second) viscosity is generally between
55 and 58 at 210°F. The oil can be blended to a finished lube by the re-
refiner or sold directly to a jobber with blending facilities. Viscosity
is increased by the addition of virgin bright stocks, or by the addition
of polyisobutylene. Conventional additive packages are used when neces-
sary to meet high performance specifications.
A-3
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DISTILLATION/CLAY TREATMENT
The distillation/clay process (Figure A) overcomes the serious acid
sludge waste disposal problem connected with acid/clay treatment. At least
two re-refiners now use 5uch a process. The following description is based
on work supported by EPA^3) and partly on patent literature U^/05).
The crude collected waste oils are received in the usual manner, in-
suring that extraneous matter does not enter the process stream. The wet
oil is heated to 300°F in a direct heater, using as fuel light hydrocarbon
streams generated during processing. The flash tower operates at atmos-
pheric pressure and 300 F. The oil/water overhead is condensed and sent on
to an oil decanter. The water phase is separated and removed to the waste-
water disposal system. The oil layer is used as fuel in the plant.
The flash tower bottoms are passed through a head exchanger to reduce
the temperature to approximately 100°F. Light oil, having a boiling range
of 150-250°F is introduced into the dehydrated oil stream. The quantity
used is approximately 20% based on oil volume. A small amount of caustic
0.2-2.0%, dependent on feedstock, is also introduced. The addition of the
light oil and caustic tends to break the oil-water emulsion and precipi-
tate solids. These materials are removed by centr1fugation. The sludge
from the centrifuge can be disposed of separately, e.g., by landfill, or
it can be mixed with the distillate bottoms to be described.
The maphtha/caustic/centrifuge pretreatment step may not be a neces-
sary adjunct to distillation, but it does tend to eliminate some of the
materials which can cause fouling and erosion in the vacuum distillation
furnace, column, and associated heat exchangers.
The centrifuged oil is then pumped to the vacuum distillation tower
through a direct fired heater. The furnace heats the oil to about 700°F.
The columns operate at a vacuum of 27 inches of mercury. The overhead
maphtha is condensed, cooled, and used as fuel in the plant.
The bottoms, which contain almost the entire ash content of the feed,
are cooled and used as fuel, for blending into asphaltic products, or
stored in a lagoon. The middle cut is sent on to clay treatment for
finishing as a lube blending stock.
The clay treatment is similar to that described for the acid/clay
process except that prior stripping is unnecessary and may be reduced to
as little as 0.125 Ibs. per gallon of oil. The filter cake is disposed
of in the usual manner.
The yields for this type operation, based on input oil, are approxi-
mately 70%, comparable to the best acid/clay treating operations.
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The product quality produced by the distillation/clay process as
described is also comparable to that produced by acid/clay treating.
However, by taking more than one sidestream from the vacuum distilla-
tion column, it may be possible to obtain a part of the yield as higher
viscosity lube stocks. The properties of some distilled motor oils are
shown in Tables 5 and 6. It is believed that clay treatment leaves
most of these properties relatively unchanged, except for improvements
in color, neutralization number, and reductions in oxygen and nitrogen
content.
Odor and wastewater problems are not believed to be any more serious
with this process than with acid/clay treatment.
A-5
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SOLVENT EXTRACTION/ACID/CLAY TREATMENT
The solvent extract ion/acid/clay process (Figure 5) is. a relatively new
development in the re-refining of waste lubricating oils. (16, 17) it has
been tried experimentally in the United States but no plants are now in
operation. A 9~mi11 ion-gallon-per-year plant is operating in Italy based on
a process developed by Institut Francais du Petrole (IFP).''°) Similar
processes have been developed and patented, but not commercialized by U.S.
firms. (17, 18)
The basis for the process is the use of propane to selectively extract
the base lube stock from the additives and impurities. The propane, con-
taining dissolved oil, is removed from the extractor, while the high boiling,
dark colored asphaltic and oxidized hydrocarbons and suspended solids are
removed from the unit bottom as a residue. The bottoms are mixed with a
fuel oil and used as plant fuel, or otherwise disposed of; whereas the pro-
pane is flashed from the oil and recycled.
The process scheme consists of the following:
a. Thermal dehydration
b. Precipitation and solvent extraction
c. Vacuum distillation
d. Acid treatment
e. Clay treatment and filtration
The incoming waste oil is unloaded into a receiving tank as described
before. The feed for the process is pumped through the steam heat exchanger
to the flash dehydrator, operated at about 300°F and atmospheric pressure.
The overhead is condensed and drained into an oil separator. The water
layer is disposed of through the waste water disposal system; the oil layer
is either stored or processed immediately in the solvent extractor.
The oil is pumped to the precipitation tower (solvent extractor) via a
head exchanger. The propane is also heated and introduced into the tower
approximately 1/3 up from the bottom. The oil is introduced 1/3 down from
the top. The solvent extractor operates at about 500 psig and elevated
temperatures. The propane-oil solution (the oil having dissolved in the
solvent) goes overhead due to specific gravity differences, whereas the
precipitate flows to the extractor bottom.
For very high quality lube oil, the solvent-to-feed ratio would be
approximately 20:1. This will vary dependent upon feed stock and must be
A-6
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determined for each one. The lowest sol vent-to-feed would be 1:1, yielding
poor quality oil in the raffinate. Current operations are believed to be
in the vicinity of 15:1-
A small amount of fuel oil is added to the pipeline to assist in the
flow of residue from the unit. The residue is released from the extractor
by a liquid level controller. The fuel oil-residue mixture is stored for
use as fuel for the direct fired heaters, or for other means of disposal.
The propane-oil solution is flashed through a pressure reducing valve
into a solvent flash drum. It is usual to use a two-stage flash to separate
the propane and oil. The first stage operates at 250°F and 250 psig. The
propane gas is liquified and recycled.
The lube oil is sent on to acid/clay treatment as described in the
acid/clay process. The acid and clay dose is approximately one-half of the
amount used without solvent extraction. That is, this process requires only
about 2% of 93% sulfuric acid by volume based on oil, compared with h-f>%
for the acid/clay process. After treatment with about 0.15 Ibs. of clay per
gallon at 300°F and filtration, the lube oil quality is reported to be
superior to the acid/clay product, at least in terms of color and color
Stability, and perhaps viscosity. These properties are shown in Table 7
and Figure ^».
Although the quantities of acid and clay required in the IFP process
are greatly reduced, a disposal problem still exists. No acid sludge analy-
sis is available, but the metals content, e.g., lead, is undoubtedly lower
than for the acid/clay process. Most of the metals and other impurities
appear in the fuel oil-residue mixture, making the use of this material as a
fuel environmentally questionable, unless accompanied by a considerable in-
vestment in air pollution control equipment, and a problem also as to fur-
nace or boiler tube fouling.
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DISTILLATION/HYDROGEN TREATING
The distillation/hydrogen treating process is similar to distillation/
clay treating, except for the finishing step, shown in Figure 6. ^ •" Al-
though this scheme is widely used in petroleum refineries, no plants are
now operating on waste oils. However, two European installations to be
started up in the period 197**"76 are apparently planning to combine hydro-
gen treating with the IFP propane extraction process previously described.
As described before, a pretreat section can be used ahead of vacuum
distillation to reduce fouling and erosion problems. The distillate (side-
stream) from the Vacuum distillation column is heated using hydrotreating
product and an oil fired heater before being mixed with recycle and makeup
hydrogen. The hydrogen-oil mixture is contacted with a standard com-
mercial hydrotreating catalyst in a fixed bed. The hydrogen reacts with
oxygen and nitrogen containing impurities and unsaturates.
The pressure is reduced in two flash drums in series and the recovered
gaseous hydrogen is recycled. The purified oil is used to preheat the in-
coming feed and then injected into a stripping column where the small
amount of volatile materials which may have formed are removed. The puri-
fied product leaving the stripper can be used to preheat vacuum distilla-
tion feed before final cooling and storage.
Recent work has shown that the hydrogen treated distillate can match
typical properties of 150 vis neutral lube blending stock. (20) Hydrotreat-
ing conditions used in this work were 650 psig, &50°F, 800 standard cubic
feet of hydrogen recycled per barrel of feed, and a space velocity of 1.0
v/v/hr.
The distillation bottoms which contain almost all of the objectionable
impurities can be disposed of as discussed before. However, in conjunction
with the distillation/hydrogen treating process development now under way,
plans are being made for introduction of this high lead material into a
secondary lead smelting operation. If this is successful as expected, the
distillation/hydrogen treating scheme holds promise as being the first re-
refining process available without a solid waste disposal problem.
As for other environmental problems, the wastewater problem is similar
to other re-refining processes and can be overcome by conventional design.
A scrubber may be required to remove impurities from the hydrogen purge
stream and other minor gaseous discharges.
Additional work on catalyst life and hydrogen consumption would be
desirable before commercialization of this process.
A-8
-------
Table 1.
ESTIMATED LUBRICATING AND nqx
INDUSTRIAL OIL SALES IN THE U. S. - 1970-7V '
Millions of
Gallons/Yr.
Automotive Lubricating Oils 1086
Commercial engine oils - fleet sales 200
Commercial engine oils - retail sales 90
Factory fills, automotive and farm 60
Private automobiles*, automobile
fleets, other 736
Aviation Lubricating Oils 8
Industrial Lubricating Oils 726
Hydraulic & circulating system oils 325
Metalworking oils 150
Railroad engine oils 60
Gas engine oils 62
Other 129
Other Industrial Oils 377
Process Oils 310
Electrical Oils 57
Refrigeration Oils 10
Federal Government 37
Exports 487
TOTAL 2721
*Approximately 600 million gallons/year; (45% = service stations;
17% = car dealers; 10% = garages, auto supply stores; 28% = mass
marketers)
-------
Table 2.
FACTORS FOR ESTIMATING THE CONVERSION OF
AUTOMOTIVE SALES TO UASTE OIL QUANTITIES
Service Stations
70% of oil sold is used for changes
Oil drained is 90% of filled capacity
70% x 90% = 63% of oil sold = waste oil generated
Garages and Auto Supply Stores
Assume average is same as service stations (63%)
New Car Dealers
100% of oil sold is used for changes
Oil drained is 90% of filled capacity
100% x 90% of oil sold = waste oil generated
Retail Sales for Commercial Engines
Assume same as service stations (63%)
Automotive Fleet and Other Lube Oil Uses
Assume 50%, allowing for two-cycle engines and
internal use, e.g., fuel, by commercial and governmental
fleets.
Factory Fills, Automotive and Farm
Assume 90% recovery in automotive service centers
Oil Bought at Discount Stores
Assume same as service stations (63%)
Assume 35% of waste oil generated finds its way to
service stations
63% x 35% = 22% of oil sold = waste oil generated at
service stations
-------
Table 3.
ESTIMATES
WASTE CRANKCASE OIL GENERATED
UNITED STATES
Source _ Million Gallons
National Estimates - Generated
(4)
American Petroleum Institute
M.E.S. State-of-the-Art 73C
Per Capita Projections - Generated
Massachusetts Survey 440
Per Capita Projection-Available for Recycle
Maryland Survey
Pittsburgh Survey 400
-------
Table 4.
ESTIMATED LUBE OIL SALES AND
WASTE OILS GENERATED AT AUTOMOTIVE SERVICE CENTERS*
1970-71
10*
Automobiles in service
stations
Automobiles in garages and
auto supply stores
Automobiles at new car
dealers
Retail sales for commercial
engines
Automotive fleet and other
lube oil uses*
Factory fills, automotive
and farm
Oil bought at discount stores
lales
5 gal/yr
270
60
102
90
136
60
168
Waste
Oil
Factor+
0.63
0.63
0.9
0.63
0.5
0.9
0.22
Waste
6011
10b gal/yr
170
38
92
57
68
54
37
*Includes motor oils, transmission oils, hydraulic oils, etc.
+See Table 3 for estimates of waste oil factors
^Marine, agricultural, etc.
-------
Table 5.
SURVEY OF SELECTED OIL RE-REFINERS: PROCESSES AND CAPACITY
Company
No. 1
No. 2
No. 3
No. 4
No. 5
No. 6
No. 7
No. 8
No. 9
No. 10
No. 11
No. 12
No. 13
No. 14
No. 15
No. 16
No. 17
No. 18
No. 19
No. 20
No. 21
No. 22
No. 23
No. 24
No. 25
No. 26
No. 27
No. 28
No. 29
Processes
Dehydration
X
X
X
X
-
X
X
-
X
X
X
-
X
-
X
X
X
X
X
X
X
-
X
X
-
-
X
X
X
-
Acid-Clay
X
X
X
X
-
X
-
-
X
X
X
-
X
-
X
X
X
X
X
X
X
-
X
X
-
X
X
X
-
-
Other
-
-
-
Batch Basis
-
3/4 Capacity
1/4 Capacity
HiPres.Dist.
-
W/Steam Strip
-
Dry.HiSpdCent
-
Caustic Clay
-
Steam Strip
-
-
Steam Strip
-
-
Caustic Clay
-
-
Caustic Clay
HC1 Act. Clay
-
-
.
-
-
Capacity^
Design
-
2,200
23,000
-
-
20,000
130,000
62,500
4,300
6,500
12,500
5,250
17,000
20,000
-
12,500
-
12,500
7,500
8,300
40,000
33,000
17,000
25,000
6,700
-
3,600
40,000
33,000
(qpd)
Operating
5,000
2,100
12,000
9,000
-
20,000
65,000
50,000
3,200
3,250
12,500
5,250
17,000
10,000
8,300
10,500
20,000
12,500
7,500
8,300
30,000
20,000
10,000
5,000
2,000
1,000
2,000
20,000
-
Waste Crankcase Oil*7
Feed gpd
4,000
2,000
12,000
-
-
16,700
-
-
2,750
3,000
11,200
4,700
-
4,100
5,000
12,000
-
-
6,250
-
-
7,000
4,500
2,000
1,000
2,000
-
-
TOTAL
AVERAGE
*0ther sources not listed
636,850
28,000
372,400
14,000
100,200
-------
Variable
Table 6.
TYPICAL WASTE AUTOMOTIVE OIL COMPOSITION
Value
Gravity, °API
Viscosity @ 100°F
Viscosity @ 410°F
Flash Point
Water (by distillation)
BS&W
Sulfur
Ash, sulfated
Lead
Calcium
Zinc
Phosphorous
Barium
Iron
Vanadium
24.6
53.3 Centistokes
9.1 a Centistokes
215°F (C.O.C. Flash)
4.4 Volume %
0.6 Volume %
0.34 Weight %
1.81 Weight %
1.11 Weight %
0.17 Weight %
0.08 Weight %
0.09 Weight %
568 ppm*
356 ppm*
5 ppm*
*ppm = parts per million
-------
Table 7.
EPA WASTE OIL PROGRAM EXPENDITURES
EPA FUNDING
($1.000)
Total Process Development 827
Institutional Development 221
National Evaluation 141
TOTAL $1,189
-------
< 3000-
O
UL.
2500-
§ 2000 -H
uj 1500-
O 1000-
< 500H
A. NEW AUTOMOTIVE OILS
B. TOTAL EQUIVALENT NEW GREASE VOLUME
fAUTO, AVIATION PLUS INDUSTRIAL)
C. TOTAL NEW INDUSTRIAL PLUS AVIATION LUBE OILS
D. TOTAL NEW OIL AND GREASE VOLUMES
D
C
A
B
1947 1950
1955
1960 1965
CALENDAR YEAR
1970
1975
VIRGIN OIL SALES IN THE UNITED STATES
Figure 1
-------
Z
o
O 1000-
u_
o
CO
Z
o
_l
_J
i
D
_j
O
500 -
TOTAL WASTE OILS
WASTE CRANKCASE OILS
D
Z
Z
WASTE INDUSTRIAL PLUS AVIATION LUBE
1965
I 1 i y
1970
CALENDAR YEAR
' I
1975
WASTE OILS GENERATED IN THE UNITED STATES
Figure 2
-------
FLASH
DEHYDRATOR
OIL SEPARATOR
-J
dW
'
WATER TO SUMP
93%
FEED
STEAM
DEHYDRATED OIL
300°F
PRE-TREATMENT
DEHYDRATID
°IL
100°F
ACID
AIR
STEAM JACKETED
TREATING TANK
ACID SLUDGE
ACID TREATMENT
* COOLER x f\
—?HJ
L ».
VOLATILE DISTILLATES
TO FUEL
WATER TO SUMP
.__„,
550 F
BATCH REACTOR
HOT OIL
^
DIRECT FIRED HEATER
CLAY SLURRY
CTeaM
STEAM
^
F,LTERS
1
SPENT CLAY
CLAY TREATMENT
LUBE STOCK
TO STORAGE
RE-REFINING BY AN ACID CLAY PROCESS
Figure 3
-------
COOLER
FEED
A
FURNACE
CAUSTIC
& NAPHTHA
FROM STORAGE
COOLER
FUEL TO STORAGE
WATER TO
PURIFICATION
FLASH TOWER
CENTRIFUGE
SLUDGE
PRE-TREATMENT
VACUUM
DISTILLATION
BOTTOM TO STORAGE
VACUUM
PUMP
NAPHTHA
TO STORAGE
REFLUX PUMP'
LUBE DISTILLATE TO CLAY TREATING
(OR HYDROTREATING)
VACUUM DISTILLATION
VACUUM DISTILLATION OF CRANK CASE WASTE OIL
Figure 4
-------
FEED
LIGHT OIL TO FUEL
*• WATER TO SUMP
PROPANE
MAKE-UP
PROPANE
COMPRESSION
& COOLING
FUEL &
RESIDUE
FLASH
DRUMS r*
r\
I FURNACE
tJ
93% H2S04
CLAY
SLURRY
FURNACE
LUBE STOCK TO STORAGE
PRE-
DISTILLATION
EXTRACTION
PROPANE
PROPANE SEPARATION RECOVERY
FINISHING
RE-REFINING BY A PROPANE EXTRACTION PROCESS
Figure 5
-------
CATALYTIC
HYDROTREATING
REACTOR
STEAM
STRIPPER
LUBE STOCK
TO STORAGE
VACUUM
DISTILLATION FEED
COOLER
T
TO FUEL
WATER TO
PURIFICATION
STEAM
TO VACUUM
DISTILLATION FURNACE
PURGE
HYDROTREATING
Figure 6
-------
REFERENCES
(1) , Sales of Lubricating Oils and Greases (1969), U.S. Department
of Commerce Series MA-29C(69)-1B; Jan. 7, 1971 & MH-29C(71)-1, 1972.
(2) Twomey, D. W., "Lube Market Getting Tighter," HPI, Nov. 1973, pg.201.
(3) Rappaport, M., Private communication, to be published as part of EPA
Waste Oil Balance Study.
(k) API, "Task Force on Waste Oil Disposal," American Petroleum Institute,
Washington, D. C.
(5) EQSI, "Waste Oil Recovery Practices - State-of-the-Art (1972)," USEPA,
Dec. 1972.
(6) A. D. Little, "Study of Waste Oil Disposal Practices in Massachusetts,"
Jan. 1969, Cambridge, Mass.
(7) Martin, E. J. and G. D. Gumtz, "State of Maryland Waste Oil Recovery
and Reuse Program," EPA Grant Sr800650, to be published.
(8) Freestone, Frank J., "Runoff of'Oils from Rural Roads," EPA R2-72-05**,
Oct. 1972, Edison, N. J.
(9) Villanova Univ., Final Progress Report, FWPCA Grant WPD-174-01-67, un-
published.
(10) GCA Corp., "Study of Waste Automotive Lubricating Oil as a Municipal
Incinerator Fuel," EPA R2-73-293, Sept. 1973, Washington, D. C.
(11) Cukor, P. M., M. J. Keaton and G. Wilcox, "A Technical and Economic
Study of Waste Oil Recovery," EPA Contract 68-Q1-l8o6, to be published.
(12) Stephens, K. C., "The Conference Board Record," May 1973, pg.^7.
(13) "Conversion of Crankcase Waste Oil into Useful Products." EPA WPCR
Series 15090 DBO, March 1971 pg-87.
(14) Chambers, J. M. Crankcase Oil Refining. U.S. Patent No. 3,173,859
March 16, 1965 9pp.
(15) Chambers, J. M. and H. A. Hadley. Crankcase Oil Reclaiming. U.S.
Patent No. 3,625,881. Dec. 7, 1971. 9pp.
(16) Bonnifay, P., et al. "A New Process for Reclaiming Spent Lubricating
Oils." Institut Francais du Petrole (Presented at the National Fuels
and Lubricants Mtg. National Petroleum Refiners Association, New York
City, Sept. 14-15, 1972.) 10pp.
-------
(17) Private Communication from Teknekron, Inc. Berkeley, Calif.
(18) Private Communication from Foster-Wheeler, Inc. Livingston, N. J.
(19) Weinstein, N. J. et al. "A Non-Polluting Oil Re-Refining Process."
RECON SYSTEMS, Inc. (Presented at American Institute of Chemical
Engineers Workshop; Industrial Process Design and Control. Chicago,
111. Oct 17-19, 1973) 1*»Pp.
(20) Bethea, S. R., et al. "To Hydrotreat Waste Oil." Hydrocarbon Processing;
p. 13^-136; September 1973-
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