RE-REFINING OF USED LUBRICATING OIL

PROJECT REPORT ON

THE RE-REFINING OF USED LUBRICANT OIL

Submitted to the University of Pune, Punein Partial Fulfilment of the Requirements

for the Award of the Degree of

BACHELOR OF ENGINEERING (CHEMICAL)

1)Gajanan R. Hange (Roll no 22)2)Vinod S. Mane (Roll no 32)3)Vrajesh K. Modi (Roll no 33)4)Vaibhav P.More (Roll no 36)

Department of Chemical EngineeringBRACT’S Vishwakarma Institute of Technology,

666, Upper Indiranagar, Bibwewadi, Pune – 411 037November 2013-14

Chemical Engineering-2013

RE-REFINING OF USED LUBRICATING OIL

Chemical Engineering-2013

RE-REFINING OF USED LUBRICATING OIL

ABSTRACT

Used oil – as its name implies – is any petroleum -based or synthetic oil that has been used. During normal use, impurities such as dirt, metal scrapings, water or chemicals can get mixed in with the oil or be generated in it due to thermal degradation or oxidation. Therefore, the oil quality gradually decreases to a level that the used oil should be replaced by a new one. Disposing the used oil off in nature creates an intense dangerous pollution. But by proper recovery and refinement of it, a lot of valuable product can be obtained. This article studies one of the best methods of used oil re-refining and compares its product specifications with those of a virgin base oil.

The re-refiner's job is to remove all the contaminants and restore the oil to its original condition. The important point to note is that the technology used by Dominion Oilis virtually identical to that used to refine crude petroleum, the difference being that the levelof contamination in used oil is much lower that that in crude oil. Used oil is uplifted from centralized collection points at places such as service stations, workshops, recycling depots and factory sites. The oil is burned at temperatures of approximately 1400oC, ensuring complete combustion. At this temperature dioxins are not formed as they may be at lower temperatures. This method has been endorsed by the Department of the Environment as the preferred alternative to re-refining.

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RE-REFINING OF USED LUBRICATING OIL

ACKNOWLEDGMENTS

It is matter of great pleasure for me to submit this project report on

“THE RE-REFINING OF USED LUBRICANT OIL”,

as a part of curriculum for award of “Bachelor of Engineering in Chemical”.

We are thankful to our seminar guide Mr A. K. VADDI, Assistant Professor in

Chemical Engineering Department for his constant encouragement and able guidance.

We are also thankful to Prof. Dr. Bhatkhande sir, Head of Chemical Engineering

Department for his valuable support.

We took this opportunity to express our deep sense of gratitude towards

those, who have helped us in various ways, for preparing our mini project. At the last

but not least, we are thankful to our parents, who had encouraged & inspired us with

their blessings.

Bansilal Ramnath Agarwal Charitable Trust’s

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RE-REFINING OF USED LUBRICATING OIL

VISHWAKARMA INSTITUTE OF TECHNOLOGY

(An Autonomous Institute Affiliated to University of Pune)

666, Upper Indiranagar, Bibwewadi, Pune – 411 037

NOVEMBER-2013

CERTIFICATE

It is certified that the project work entitled

“THE RE-REFINING OF USED LUBRICATING OIL”

Submitted by

1)Gajanan R. Hange Gr. No. 111251 Roll No.222)Vinod S. Mane Gr. No.111381 Roll No.323)Vrajesh K. Modi Gr. No.111027 Roll No.334)Vaibhav P. More Gr. No. 11453 Roll No.36

is the original work carried out by them under the supervision of Prof. A. K. Vaddi and is approved for the partial fulfilment of the requirement of University of Pune, Pune for the award of the Degree of Bachelor of Engineering (Chemical)

This Project Work has not been earlier submitted to any other Institute or University for the award of any degree or diploma.

(Prof. A. K. Vaddi) (Dr. D. S. Bhatkhande) Guide H.O.D Chem engg dept. Chem engg dept.

TABLE OF CONTENTS

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RE-REFINING OF USED LUBRICATING OIL

ABSTRACT

ACKNOWLEDGEMENT

CERTIFICATE

Chapter 1 INTRODUCTION

Importance Oil chemistry

Chapter 2 LUBE OIL

Properties Theory

Chapter 3 USED LUBE OIL

Used oil composition

Chapter 4 NEED FOR RE-REFINING

Importance and Benefits

Chapter 5 PROCESSES INVOLED IN RE-REFINING PROCESS Dehydration Vacuum distillation Lube oil Distillation and Condensation

Chapter 6 PROCESS DESCRIPTION

Dehydration Vacuum distillation Lube oil Distillation and Condensation

Chapter 7 ENVIRONMENTAL ISSUES

Chapter 8 MATERIAL BALANCE AND PROPERTY COMPARISON

Chapter 9 CONCLUSION

REFERENCES

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INTRODUCTION

Lubricating oil is an important resource. One of the more valuable lubricating oils is themotor oil used in passenger cars, vans, and trucks. Every year, privately ownedautomobiles and light trucks in the U.S. generate over 300 million gallons of usedcrankcase oil.

Mismanagement of used motor oil is a serious environmental problem. All automotiveoils have the potential to be recycled safely and productively, saving energy and avoidingenvironmental pollution. Unfortunately, most used motor oil is handled improperly.Some is emptied into sewers, adversely affecting water treatment plants or going directlyinto waterways. Some is dumped directly onto the ground to kill weeds or is pouredonto dirt roads. Millions of gallons are thrown into the trash, ending up in landfills,where it can contaminate surface and ground water.

In addition to the environmental problems, improper used oil disposal is simply a wasteof a valuable resource. Every gallon of used motor oil not recovered results in the need todrill for more oil and in some cases it results in increases in oil import. Today, however, most of the crude petroleum produced throughout the world contains very little of the specialhydrocarbon chains necessary for motor oil. As a result, refining crude petroleum toproduce virgin lube oil is an elaborate, complex, and expensive process that requiresnearly three times as much energy as rerefining used oil.

Lube base oil is one of the most valuable components in a barrel of crude oil. While many components of crude oil such as gasoline, jet and diesel fuels are ‘lost’ after combustion, lubebase oil can be recovered and ‘regenerated’ to the quality equal to or better than its original virgin form.

The re-refiner's job is to remove all the aforementioned contaminants and restore the oil to itsoriginal condition. The important point to note is that the technology used by Dominion Oilis virtually identical to that used to refine crude petroleum, the difference being that the levelof contamination in used oil is much lower that that in crude oil.

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OIL CHEMISTRY

Petroleum products are essentially composed of hydrocarbons, i.e. compounds containingexclusively carbon and hydrogen. The simplest hydrocarbon molecule is methane, CH4.This basic molecule is the main constituent of natural gas. It can be extended with theaddition of more carbon and hydrogen atoms, usually forming into longer chains. Fourcarbon atoms in a chain forms butane, one of the main constituents of LPG. The atoms mayalso form side chains off the main chain, or form into ring structures such as the benzenering. Lubricating oils are just extensions of these basic hydrocarbon structures, containingfrom 20 to 70 carbon atoms per molecule, often in an extremely complex arrangement ofstraight chains, side chains and five and six membered ring structures

The lubricating oil molecules can be divided into three broad groupings:

Paraffinic: Predominantly straight chains, tend to be waxy, have a high pour point andgood viscosity/temperature stability.

Naphthenic: Straight chains with a high proportion of five and to a lesser extent six membered ring structures. Tend to have a low pour point. For this reasonthey are used as refrigeration oils. They are highly carcinogenic and are littleused in engine oil. Dominion Oil treats used refrigerator oils separately fromthe main plant. As refrigerator oils do not come in contact with products ofcombustion they are much cleaner than engine oils.

Aromatic: Straight chains with six membered ring benzene structures.In practise, no sharp distinction exists between these various groupings as many lubricatingoil molecules are a combination, to varying degrees, of the different types of hydrocarbons.The main point to bear in mind is that these molecules are extremely stable. Lubricating oilmolecules never wear out - all that happens is that the additives in the oil wear out or depleteand need replacing.

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LUBE OIL

Motor oil or engine oil is an oil used for lubrication of various internal combustion engines. The main function is to lubricate moving parts; it also cleans, inhibits corrosion, improves sealing, and cools the engine by carrying heat away from moving parts.

Motor oils are derived from petroleum-based and non-petroleum-synthesized chemical compounds. Motor oils today are mainly blended by using base oils composed of hydrocarbons, polyalphaolefins (PAO), and polyinternal olefins] (PIO), thus organic compounds consisting entirely of carbon and hydrogen. The base oils of some high-performance motor oils however contain up to 20% by weight of esters

Motor oil is a lubricant used in internal combustion engines. These include motor or road vehicles such as cars and motorcycles, heavier vehicles such as buses and commercial vehicles, non-road vehicles such as go-karts, snowmobiles, boats (fixed engine installations and outboards), lawn mowers, large agricultural and construction equipment, locomotives and aircraft and static engines such as electrical generators. In engines, there are parts which move against each other causing friction which wastes otherwise useful power by converting the energy to heat. Contact between moving surfaces also wears away those parts, which could lead to lower efficiency and degradation of the engine. This increases fuel consumption, decreases power output and can lead to engine failure.

Lubricating oil creates a separating film between surfaces of adjacent moving parts to minimize direct contact between them, decreasing heat caused by friction and reducing wear, thus protecting the engine. In use, motor oil transfers heat through convection as it flows through the engine by means of air flow over the surface of the oil pan, an oil cooler and through the build up of oil gases evacuated by the Positive Crankcase Ventilation (PCV) system.

In petrol (gasoline) engines, the top piston ring can expose the motor oil to temperatures of 160 °C (320 °F). In diesel engines the top ring can expose the oil to temperatures over 315 °C (600 °F). Motor oils with higher viscosity indices thin less at these higher temperatures.

Coating metal parts with oil also keeps them from being exposed to oxygen, inhibiting oxidation  elevated operating temperatures preventing rust or corrosion. Corrosion inhibitors may also be added to the motor oil. Many motor oils also have detergents and dispersants added to help keep the engine clean and minimize oil sludge build-up. The oil is able to trap soot from combustion in itself, rather than leaving it deposited on the internal surfaces. It is a combination of this, and some singeing that turns used oil black after some running.

Rubbing of metal engine parts inevitably produces some microscopic metallic particles from the wearing of the surfaces. Such particles could circulate in the oil and grind against moving parts, causing wear. Because particles accumulate in the oil, it is typically circulated through an oil filter to remove harmful particles. An oil pump, a vane or gear pump powered by the engine, pumps the oil throughout the engine, including the oil filter. Oil filters can be a full flow or bypass type.

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Most motor oils are made from a heavier, thicker petroleum hydrocarbon base stock derived from crude oil, with additives to improve certain properties. The bulk of a typical motor oil consists of hydrocarbons with between 18 and 34 carbon atoms per molecule. One of the most important properties of motor oil in maintaining a lubricating film between moving parts is its viscosity. The viscosity of a liquid can be thought of as its "thickness" or a measure of its resistance to flow. The viscosity must be high enough to maintain a lubricating film, but low enough that the oil can flow around the engine parts under all conditions. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes. A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.

Motor oil must be able to flow adequately at the lowest temperature it is expected to experience in order to minimize metal to metal contact between moving parts upon starting up the engine. The pour point defined first this property of motor oil, as defined by ASTM D97 as "... an index of the lowest temperature of its utility ..." for a given application, but the "cold cranking simulator" and "Mini-Rotary Viscometer" are today the properties required in motor oil specs and define the SAE classifications.

USED LUBE OIL

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Used lube oil is defined as the petroleum derived or synthetic oil which remains after applications in lubrications, cutting purposes, etc After a certain period of useful life, the lubricating oil loses its properties and cannot be used as such in machinery. Build up of temperature degrade the lubricating oil, thus leading to reduction in properties such as : Viscosity, Specific gravity, etc Dirt and metal parts worn out from the surfaces are also deposited into the lubricating oils. With increased time of uses, the lubricating loses its lubricating properties as a result of over reduction of desired properties and thus must be replaced with fresh one.

USED OIL COMPOSITION

A lubricating oil becomes unfit for further use for two main reasons: accumulation ofcontaminants in the oil and chemical changes in the oil. The main contaminants are listedbelow.

Combustion products

Water: Fuel burns to CO2 and H2O. For every litre of fuel burnt, a litre of water is created. This normally passes out through the exhaust when the engine is hot, but when cold it can run down and collect in the oil. This leads to sludge formation and rust.

Soot and carbon :These make the oil go black. They form as the result of incompletecombustion, especially during warm-up with a rich mixture.

Lead :Tetraethyl lead, which used to be used as an anti-knock agent in petrol, passes into the oil. A typical used engine oil may have contained up to 2% lead, but today any lead comes from bearing wear and is likely to be in the 2 - 12 ppm range.

Fuel: Unburnt gasoline or diesel can pass into the lubricant, again especially during start-up.

AbrasivesRoad dust: This passes into the engine through the air-cleaner. Composed of small particles of silicates. Wear metals. Iron, copper and aluminium released due to normal engine wear.

Chemical products

Oxidation products: Some of the oil molecules, at elevated temperatures, will oxidise toform complex and corrosive organic acids.

Depleted additive remnants :The Hydrocarbon composition of new or used automotive lubricating oil sludge consists primarily of saturated compounds such as Linear and Branched

chain, Paraffin's which have at least twice as many Naphthenic. Aromatics generally

comprise about 10 to 15 weight % of the hydrocarbon base material. Composition of used oil consists of four major groups, which have average values of 76.7% saturates, 13.2% monoaromatics, 3.7% diaromatics and 6.5% polyaromatic-polar material.

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NEED FOR REREFINING

1) The need to conserve crude reserves.2) Minimizing unemployment through the building of used lube oil recycling plant.3) The elimination environment pollution source of used lubricant.

IMPORTANTS AND BENEFITS OF RE-REFINING

1) Reduce dependence on base oil imports saving foreign exchange.2) Prevent ground water contamination and pollution.3) Preserve natural resources such as coal and crude oil.4) Reduce sewage treatment costs.5) Eliminate improper burning of waste oil as fuel, which generate toxic fumes and air

pollution.

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PROCESSES INVOLVED IN RE-REFINING PROCESS

The re-refiner's job is to remove all the aforementioned contaminants and restore the oil to itsoriginal condition. The important point to note is that the technology used by Dominion Oilis virtually identical to that used to refine crude petroleum, the difference being that the levelof contamination in used oil is much lower that that in crude oil. Used oil is uplifted from centralised collection points at places such as service stations, workshops, recycling depots and factory sites. The collector is contracted to the Used Oil Monitoring Group, whose members include BP, Dominion Oil Refining, Caltex, Castrol, Shell, Milburn Cement and the Department of the Environment. Milburn Cement administer the Group, whilst the Department of the Environment represent the Government. Milburn Cement also combust any used oil that cannot be recycled, using it as an alternative to coal. The oil is burned at temperatures of approximately 1400oC, ensuring complete combustion. At this temperature dioxins are not formed as they may be at lower temperatures. This method has been endorsed by the Department of the Environment as the preferred alternative to re-refining.

Step 1 - DehydrationThe oil is stored to allow water and solids to separate out from the oil, then the oil is heatedto 120oC in a closed vessel to boil off any emulsified water and some of the fuel diluents.

Step 2 - Diesel strippingThe dehydrated oil is then fed continuously into a vacuum distillation plant for fractionationin exactly the same fashion as crude petroleum. The fractions obtained are as follows:

1. Light fuel and diesel: Dominion Oil produces enough diesel from the used oilfeedstock to run all the burners and boilers, giving total self-sufficiency in fuel.

2. Lubricating oi: The bulk of the feedstock will distill off in the plant to produce alubricating oil fraction.

3. Residue: The non-distillable part of the feedstock. This contains all the carbon, wearmetals, degraded additives and most of the lead and oxidation products. This residueis successfully used as bitumen extender for roading.

Step 3 - Lube oil distillation and condensationThe lubricating oil fractions are then passed through an extraction tower in the presence of Nmethylpyrolidone (NMP). The NMP is an aromatic selective solvent which, in addition toremoving some colour and odour, is able to extract all unwanted aromatic contaminantspresent in the paraffinic lubricating oil fraction, subsequent to fractional distillation. This isimportant as polycyclic aromatics are very carcinogenic. This process is commonly used invirgin oil refineries, but Dominion Oil Refining is the only manufacturer of re-refined oil to use it.

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PROCESS DISCRIPTION

STEP-1: DEHYDRATION

The oil is stored to allow water and solids to separate out from the oil, then the oil is heatedto 120oC in a closed vessel to boil off any emulsified water and some of the fuel diluents.

The point at which an oil contains the maximum amount of dissolved water is termed the saturation point. The saturation point is dependent on the oil’s temperature, age and additive composition. The higher the temperature, the higher the saturation point and hence more water held in solution, in the dissolved phase. This is the same as being able to dissolve more sugar in hot water, than in cold water. Similarly, the older the oil, the higher the level of water that can be dissolved. This is due to polar by-products of oxidation in the oil, which act as “hooks” holding on to the water molecules and keeping them in solution. Likewise, highly additized oils, like crankcase oils, have a higher saturation point than lightly additized oils like turbine oils, because the additives - many of which are polar - also hold the water in solution.

Water can also affect the additive package through water washing and hydrolysis, leading to acids and additive depletion. Water encourages rust and corrosion and will cause increased wear as a result of aeration, changes in viscosity resulting in film strength failure, hydrogen blistering and embrittlement, and vaporous cavitation. Finally, water is a generator of other contaminants in the oil such as waxes, suspensions, carbon and oxide insolubles and even micro-organisms.

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STEP-2 : VACUUM DISTILLATION

Petroleum  oil is a complex mixture of hundreds of different hydrocarbon compounds generally having from 3 to 60 carbon atoms per molecule, although there may be small amounts of hydrocarbons outside that range. The refining of crude oil begins with distilling the incoming crude oil in a so-called atmospheric distillation column operating at pressures slightly above atmospheric pressure.

In distilling the oil, it is important not to subject the crude oil to temperatures above 370 to 380 °C because the high molecular weight components in the crude oil will undergo thermal cracking and form petroleum coke at temperatures above that. Formation of coke would result in plugging the tubes in the furnace that heats the feed stream to the crude oil distillation column. Plugging would also occur in the piping from the furnace to the distillation column as well as in the column itself.

The constraint imposed by limiting the column inlet crude oil to a temperature of less than 370 to 380 °C yields a residual oil from the bottom of the atmospheric distillation column consisting entirely of hydrocarbons that boil above 370 to 380 °C.

To further distill the residual oil from the atmospheric distillation column, the distillation must be performed at absolute pressures as low as 10 to 40 mmHg (also referred to as Torr) so as to limit the operating temperature to less than 370 to 380 °C.

Figure 2 is a simplified process diagram of a petroleum refinery vacuum distillation column that depicts the internals of the column and Figure 3 is a photograph of a large vacuum distillation column in a petroleum refinery.

The 10 to 40 mmHg absolute pressure in a vacuum distillation column increases the volume of vapor formed per volume of liquid distilled. The result is that such columns have very large diameters.

Distillation columns such those in Images 1 and 2, may have diameters of 15 meters or more, heights ranging up to about 50 meters, and feed rates ranging up to about 25,400 cubic meters per day (160,000 barrels per day).

The vacuum distillation column internals must provide good vapor-liquid contacting while, at the same time, maintaining a very low pressure increase from the top of the column top to the bottom. Therefore, the vacuum column uses distillation trays only where withdrawing products from the side of the column (referred to as side draws). Most of the column uses packing material for the vapor-liquid contacting because such packing has a lower pressure drop than distillation trays. This packing material can be either structured sheet metal or randomly dumped packing such as Raschig rings.

The absolute pressure of 10 to 40 mmHg in the vacuum column is most often achieved by using multiple stages of steam jet ejectors.

Many industries, other than the petroleum refining industry, use vacuum distillation on a much a smaller scale.

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Laboratory-scale vacuum distillation

Laboratory-scale vacuum distillation, sometimes referred to as low temperature distillation, is used when the liquids to be distilled have highatmospheric boiling points or undergo a chemical change at temperatures near their atmospheric boiling points.Temperature sensitive materials (such as beta carotene) also require vacuum distillation to remove solvents from the mixture without damaging the product.There many laboratory applications for vacuum distillation as well as many types of distillation setups and apparatuses. Image 3 is a photograph of a vacuum distillation setup in a laboratory.Safety is an important consideration when using glassware as part of the setups. All of the glass components should be carefully examined for scratches and cracks which could result in implosions when the vacuum is applied. Wrapping as much of the glassware with tape as is practical helps to prevent dangerous scattering of glass shards in the event of an implosion.

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The dehydrated oil is then fed continuously into a vacuum distillation plant for fractionationin exactly the same fashion as crude petroleum. The fractions obtained are as follows:

1. Light fuel and diesel: Dominion Oil produces enough diesel from the used oilfeedstock to run all the burners and boilers, giving total self-sufficiency in fuel.

2. Lubricating oil: The bulk of the feedstock will distill off in the plant to produce alubricating oil fraction.

3. Residue: The non-distillable part of the feedstock. This contains all the carbon, wearmetals, degraded additives and most of the lead and oxidation products. This residue is successfully used as bitumen extender for roading.

STEP-3: LUBE OIL DISTILLATION AND CONDENSATION

The lubricating oil fractions are then passed through an extraction tower in the presence of Nmethylpyrolidone (NMP). The NMP is an aromatic selective solvent which, in addition toremoving some colour and odour, is able to extract all unwanted aromatic contaminantspresent in the paraffinic lubricating oil fraction, subsequent to fractional distillation. This isimportant as polycyclic aromatics are very carcinogenic. This process is commonly used invirgin oil refineries, but Dominion Oil Refining is the only manufacturer of re-refined oil to use it.

Liquid–liquid extraction also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. It is an extraction of a substance from one liquid into another liquid phase. Liquid–liquid extraction is a basic technique in chemical laboratories, where it is performed using a separatory funnel. This type of process is commonly performed after a chemical reaction as part of the work-up.

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Environmental Issues

Oil in any form is potentially harmful to the environment. Post-studies of oil spills indicatethat it takes up to twenty years for an aquatic environment to return to a healthy condition.Once oil has been used by industry or the DIY, it has even more potential for environmentaldamage. In aquatic communities oil residue tends to settle on the bottom, coating the substrate and whatever organisms live there. When poured on the ground, oil can rapidly migrate through the soil. In both instances, bacteria, plants, invertebrates, and vertebrates experience physiological stress. Oil film on water can reduce the penetration of light into the water and, consequently, reduce the rate of photosynthesis. When photosynthesis is reduced, oxygen production is also reduced. The oil film may also inhibit the movement of oxygen from the air through the surface of the water. The reduction of dissolved oxygen in the water stresses animals living in the water. Oil can clog respiratory (breathing) mechanisms and even be incorporated into the tissues of these organisms. These substances in the tissues of the organisms make them unfit for human consumption and, therefore, contribute to economic loss. If the contaminants are not incorporated into a human food source, they may be passed along the food chain, thereby contributing to environmental degradation.Some of the substances found in both virgin crude and refined oil can affect the nervoussystems of living things. This reduces their ability to find food or reproduce. Some of the oil components (on the light end) evaporate into the air and/or dissolve into the water. Many of these light end compounds are known carcinogens and/or mutagens.Microscopically, oil compounds impinge on algae, bacteria, and plankton, the basis of theaquatic food chain. Larger organisms such as mammals and birds are the most dramaticvictims of oil pollution because of their visibility and emotional appeal to humans. Feathersand fur become coated with oil and lose their ability to control body temperature. Deathresults from exposure or ingestion of the oil compounds via grooming.In ground, oil can rapidly percolate through the soil particles and create similar problems forsoil microbes and macroscopic invertebrates. Eventually this oil may make its way into thewater table or into a water body such as a lake. Used oil is a valuable resource. One definition for pollution is a resource out of place, andused oil certainly fits that description. The potential impact on our environment depends onhow we manage this resource to make sure it is not out of place. To summarize, pollution can be defined as a resource in the wrong place or one that has not been completely used. Improper disposal of used oil is a source of significant pollution. The potential impact on our water and environment is serious. Of all petroleum related pollution in the U.S. including oil spills in coastal waterways, 62% is estimated to be runoff of used lubricating oil, much of which eventually works its way to the ocean environment.

Economic Impact of Disposal Methods

The energy saved by collecting and recycling used motor oil can help reduce our dependenceon foreign oil imports. Although current crude oil prices have dropped in recent years,valuable energy reserves can be conserved by the use of fuel oil made from reclaimed motoroil. One gallon of used oil can be re-refined into 2-1/2 quarts of quality lubricating oil. In

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contrast, 42 gallons of crude oil must be refined to produce the same 2-1/2 quart volume(though many other products are derived from the 42 gallons of crude). In fact, recyclingused oil could reduce petroleum imports by 25.5 million barrels of oil per year, saving 1.3 million barrels of oil per day or half the annual production of the Alaskan pipeline.

SCHEMATIC OF RE-REFINING PROCESS

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CALCULATIONS

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COMPARISON OF PROPERTIES

Properties Pure oil Used oilColor & appearance

Clear& homogeneous

Clear &homogeneous

Specific gravity 0.882 0.910Dynamic viscosity

312 324

Water, volume% 0 12Flash point 234 264

Material balance

FEEDSTOCK

Waste lube oil

PRODUCTS

Off gases(Water, light ends and losses)Base oilGas oilResidue

TOTAL

ML

200

161401232

200

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CONCLUSION

1) Used oil is pollutant and by re-refining, the pollution is reduced. Hence it should get a status of eco-friendly technology and get grants and incentives from the ministry of enviourment.

2) The quality of thoroughly re-refined oil is comparable with nascent base oil. Hence it should be evaluation awarded import-substitute status.

3) While making fresh lubricating oils blending with 5-10% of re-refined base oils should be done for viscosity correction.

4) All such blended oils should be stamped with green lable to make the public aware about the concept of re-refining.

5) The eco-conscious customer would buy the product with green labels.

6) Since re-refining leads to oil conservation the concept of re-refining should be strongly supported by the petroleum conservation research association.

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REFERENCES

1) "Used Oil. A Renewable Resource and an Environmental Pollutant" by David Layzell,

2) L.M. Magnabosco and W.A. Rondeau, "Improved Process forthe Production of Base Stock Oils from Used Oil.,

3) Frankl, P., Fullana, P., Baitz, M., 2005, Europe Life Cycle Considerations on Waste Oils and Implications. 4) “Recycling Used Motor Oil: A Model Program.” Third

Edition,December, 1988.

5)Hunter, B. Scott. “Disposing of Used Motor Oil: A Slippery Issue.” Delaware Valley Energy Report, Volume 8, Number 1, Winter 1991/92.

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