[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO1992018590A1 - Enlevement des contaminants de l'huile lubrifiante usee - Google Patents

Enlevement des contaminants de l'huile lubrifiante usee Download PDF

Info

Publication number
WO1992018590A1
WO1992018590A1 PCT/AU1992/000172 AU9200172W WO9218590A1 WO 1992018590 A1 WO1992018590 A1 WO 1992018590A1 AU 9200172 W AU9200172 W AU 9200172W WO 9218590 A1 WO9218590 A1 WO 9218590A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil
clay
process according
acid
mixture
Prior art date
Application number
PCT/AU1992/000172
Other languages
English (en)
Inventor
Douglas Johnstone Stevenson
Original Assignee
Crystal Oil Aust Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Crystal Oil Aust Pty Ltd filed Critical Crystal Oil Aust Pty Ltd
Publication of WO1992018590A1 publication Critical patent/WO1992018590A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M175/00—Working-up used lubricants to recover useful products ; Cleaning

Definitions

  • the invention relates to a one step process for removing contaminants from used lubricating oil. More particularly the invention involves contacting the used oil with a pre treatment chemical and clay at elevated temperature and thereafter filtering the treated used oil to remove essentially all the contaminants.
  • Waste lubricating oils are renewable resources that should be recycled to preserve natural resources and avoid contamination of the environment.
  • Waste lubricating oils include used motor oil, diesel oil, crankcase oil, transmission oil, and the like, usually collected from gasoline service stations. These waste oils contain a number of contaminants arising both from their use and from additives added prior to their use. These contaminants, for the most part, include calcium, barium, zinc, aluminium and phosphorus arising from detergent dispersant agents, iron from engine wear, lead and light end hydrocarbons from gasoline, and water. In order to reuse these oils, the contaminants must be substantially removed.
  • waste oils are treated in a process which includes metals removal steps, which steps involve coagulating or precipitating the contaminants and thereafter either filtering the oil or removing the metals in an aqueous phase. Often the oil is then clay contacted to remove further colour bodies or metals remaining after the initial metals removal.
  • metals removal steps One of the most widely used metal removal steps is the acid-clay process.
  • the light ends are first removed from the oil by steam stripping at a temperature in the range of about 260-345 °C.
  • the oil is then contacted with high strength sulfuric acid to precipitate contaminants into the aqueous phase; the contaminants are then removed as an acid sludge.
  • the remaining acidic oil product is thereafter contacted with clay at a temperature in the range of about 149-315°C. to absorb additional contaminants and colour bodies.
  • the primary step in the use of sulfuric acid for removing metals and other impurities from the used oils requires removal of water contained in the as collected used oil as it would react with sulfuric acid causing violent reactions.
  • the amount of sulfuric acid required for this type of process varies from 4-10% of dry oil depending on the amount of additives used for blending the virgin oil prior to use and the amount of impurity in the used oils. The higher amount the impurity and the additives the more acid is required, and the higher the loss of used oils as acid sludge. Normally, the amount of acid sludge produced is twice the volume of the acid used.
  • the oils remaining are treated with clay at 250-300 °C for further removal of impurities and colour improvement.
  • the amount of clay used varies from 2-10% depending on the activity and capacity of the clay.
  • Wiped film evaporator (NL 83 04023) along with high temperature thermal cracking stage (300-350°C) reactors (DE 3 023 374 C2) have been used to different degrees of success to remove part of the impurity and additives from the used oils.
  • the pretreated oil still requires post-treatment with the sulfuric acid and clay to improve its colour and quality for use as lubricants.
  • the amount of acid has been normally reduced to the 2-7% range but total elimination of the sulfuric acid pre treatment step has not been accomplished along with the need of the clay which normally varied from 2-10%.
  • the amount of clay required depends on its acidity and activity.
  • waste oil is contacted with an aqueous solution of ammonium sulfate and aluminium sulfate.
  • the pre treatment chemicals are added to the waste oil in an aqueous solution and the metals are separated in an aqueous phase.
  • the temperature of the reaction is limited to about 90°- 260°C. High temperature treatments have generally been avoided when reprocessing waste lubricating oils to avoid cracking of the oil.
  • a waste lubricating oil is contacted with one or more of the pre treatment chemicals selected from the group consisting of ammonium sulfate, ammonium bisulfate, diammonium phosphate, ammonium dihydrogen phosphate, calcium hydrogen phosphate, phosphoric acid, calcium sulfate, aluminium sulfate, sodium sulfate, and magnesium sulfate.
  • the contacting step is performed at a temperature of at least about 345 °C. This high temperature of at least about 345 °C. is used to ensure removal of light hydrocarbon ends from the waste oil.
  • Lubricating oils generally are defined as having a boiling point above at least about 345 °C.
  • the oil mixture is thereafter filtered to obtain a filtrate product reduced in contaminant content.
  • the pre treatment chemical is preferably added to waste oil in the absence of water.
  • the required pre treatment chemicals to be used in the invention is relatively high varying from 1-5%. It is noted that when large amounts of it is used, substantial amount of SO x in the gaseous effluent is also generated causing environmental concern. Furthermore, the pretreated used oil must be filtered (causing a yield loss) and post treated with clay or the hydro treating steps to improve its colour and quality.
  • the filtered oil product needs further conventional upgrading processes including hydro treating, vacuum distillation and acid-clay contacting.
  • it is useful as is in non-critical circumstances, such as lubrication of railroad cars.
  • the clay amount used in the pre treatment process is limited to 2-6% by wt. and the oil mixture is heated to 340-360°C for about 1-2 hours. Quantity of clay larger than 6% is not normally recommended due oil loss in the clay. Temperature higher than 360°C is also not normally recommended due to over cracking of oil at such high temperatures.
  • a process for the removal of contaminants from used lubricating oil comprising (a) contacting the oil with catalysts containing inorganic compounds and clays and agitating and heating the resultant mixture so as to effect the selective cracking of said mixture; (b) decreasing the temperature and maintaining agitation for a time sufficient to complete the reaction; and (c) cooling and removing the residue from said mixture.
  • an oil additive for rendering contaminants in used lubricating oil inactive comprising inorganic compounds and clays.
  • a previously untreated used lubricating oil containing detergent dispersant agents, may be contacted with pre treatment chemical (catalyst) and acid activated clay in one single reactor heated for a specified time at a specified temperature with the result that the so-treated oil-clay mixture may thereafter be directly and successfully cooled and filtered to remove essentially all the contaminants with the solids and yield a light colour oil directly suitable for reblending with additives prior to cense as lubricants.
  • the ratio of the catalyst and clay used could vary over a large range. Generally speaking, the higher amount of catalyst used the lower amount of clay is required, and the reverse is true also.
  • the ratio of the catalyst and the clay should be controlled to optimise the formation of SO x by product in the effluent and oil loss in the clay. It is preferred that the amount of the catalyst and the acid activated clay be used in the range of less than 1-2% and 4-15%, respectively.
  • Fig. 1 depicts a flow diagram depicting the process of the present invention.
  • BEST MODE AND OTHER MODES FOR CARRYING OUT THE INVENTION The concept discussed below is a continuous process which uses an active clay system that eliminates the need of sulfuric acid treatment and produces a clean oil for re-use.
  • the used oil to be processed could be any black oil as is normally understood or any white oil that has been substantially contaminated.
  • the clay could be F-30 from Engelhard or any other clay that possesses similar properties.
  • the process could include a mixer (A), a preheater (B), a heater exchanger (C), a continuous (stirred tank) reactor (D) a condenser (E), and a continuous or a semi-batch filter (F) as depicted in Figure 1.
  • the used oil is fed continuously from the storage tank into the mixer where the clay is uniformly mixed with the used oil and preheated before being fed into the bottom of the continuous stirred tank reactor at a specified temperature.
  • the used oil would have a specified residence time (1-4 hours) in the reactor while being discharged continuously from the top of the reactor.
  • the reaction temperature of the reactor should be high enough to finish cracking of the detergent or other additives in the used oil. Temperature required before entering the reactor at 300-350°C must be preheated to 320-380°C for sufficient time (5-20min.) to affect cracking of the detergent and other additive.
  • the processed oil discharged from the reactor is cooled and fed into a continuous belt filter or a semi-batch type filter to separate the clean oil from the used clay.
  • the used oil could be demetallized using for example the Diammonium phosphate (i.e. Philips process) prior to entering into the clay mixer.
  • the purpose is to avoid metal deposition on the clay.
  • the subsequent process scheme could be the same as without the demetallization step discussed above.
  • the process could either be practiced batchwise, semi-batchwise or continuously, depending on the plant capacity and economics preference. Since there is no acid pre treatment step required, no acid sludge settlement tanks and sealed transfer lines are required, and there is no down time required for settlement of the acid sludge either. Therefore, even with batch operation, one operation cycle would normally require less than 4-5 hours which is equivalent to 1/3 to - . the time required for the conventional contacting process not counting the acid pre treatment time. Furthermore, significantly less land is required favouring tight space operation capability. The new process, therefore, provides savings in capital and operating expenses.
  • the as collected oil normally contains 4-10% water which does not require preliminary removal beforehand. Preferably some water (up to 5%) is added if the total initial water content is less than 4%.
  • the used oil is preferably treated directly by the present process without preliminary light ends stripping. Since the contacting step of the process utilises a high temperature, light ends stripping is conveniently performed simultaneously with this step. Alternatively the process may be practised with a preliminary, intermediate or final light ends stripping step.
  • the stripping could be either conducted by slight vacuum to effect distillation or by supersaturated steam. With proper stripping the colour and smell of the oil product has improved colour.
  • Used oil prepared by preliminary thermal cracking steps seems to be more difficult to treat using the present invention probably due to clay fouling.
  • the clay contacting step could also be performed in a hydrogen atmosphere. Improvements in the odour of the oil could be obtained due to the hydrogenation of S-containing compounds.
  • the catalyst added to the acid activated clays and the oil mixture could be in either aqueous form or dry form containing phosphate sulfate and/or chloride cations. They can also be pre blended with acid activated clay before being mixed in the clay treaters.
  • the catalyst amount required is normally no more than 2% and is preferably less than 1 % .
  • the clay preferred is acid activated (and acid activatable) montmorilonite type bentonites.
  • the acid activated clay may be activated by any suitable acid known in the art, for example sulfuric acid or hydrochloric acid. When neutral clay unactivated by acid is used, generally sulfuric acid could be used proportionately to activate the clay in-situ inside the same reactors at lower temperatures before the final reactor temperature is reached.
  • the used oil after preheating to 200-250 °C is preferably heated subsequently in a direct fired heat box to reach a maximum temperature of 340-380 °C to effect the selective cracking of impurities and additives.
  • the residence time in the maximum temperature is to be no more than 20 minutes and preferably 5-10min. Too long a residence time under the maximum temperature could cause undue cracking of oil.
  • the high temperature treated oil entering into the continuous recycled or stirred tank reactor is preferably kept for a residence time of 1-2 hours and no more than 4 hours to ensure completion of the reactions.
  • the finished used oil mixture is then circulated to the preheater for preliminary cooling before it is finally cooled in a heat exchanger to 100- 150°C before filtration.
  • the gaseous product produced from the clay reactor can be condensed and fractionated to produce various distillate products as the conventional process.
  • the treated oil after filtration has colours ranging from 1.5-4 depending on the colour specification required. Generally the lower the colour the higher the catalyst or clay loading is required, but normally no more than 15% clay is required for an ASTM colour of 1.5-3.
  • the preferred clay loading is in the range 5-12.5% by wt of the used oil. Lower than 5% the colour of the product oil could be too dark. While higher than or equal to 12.5% clay is used, a strong acidic clay could effect the cracking of the additives to produce clean oil product without added catalyst.
  • crankcase oils Three used crankcase oils were subjected to re-refining in this investigation. These oils, their sources and descriptions were as follows:
  • the three catalyst components are understood to have been purchased from Van Waters & Rogers Ltd., Richmond, B.C. by Hy Pow'r. 2 Refining Methods Preparation of Samples for Analysis Initially (Runs 1 to 6) a 1L 3-neck flask fitted with a stirrer, thermometer and distillation take-off head plus condenser and receiver was used to treat used oil with catalyst. The apparatus was heated to temperature using an electrically heated mantle. The D-shaped Teflon plastic stirrer blade used was capable of sweeping approximately 80cm---* of the flask bottom, an area sufficient to agitate the entire amount of catalyst and clay. The rate of agitation was approximately 60rpm. Later experiments (Runs 7 to 9) employed a 2L 3-neck flask with the same accessories. The use of a larger flask was necessary in order to accommodate the large volume of foam generated during the reaction process.
  • Solids including catalyst, clay, coagulated oil impurities and entrained re-refined oil were analysed at B.C.
  • Research for zinc and lead the procedure involved ashing the material removed from the oil by filtration at 800°C, digesting the residues with 50X nitric acid, filtering off insolubles, diluting to known volume and measuring the metal contents by atomic absorption spectrophotometry (AA).
  • AA atomic absorption spectrophotometry
  • Table 1 summarises data gathered in 9 separate experiments where different used oils were treated with the standard Hy Pow'r catalyst consisting of equal quantities of the three catalyst components. Attempts to gather quantitative yield data were frustrated initially by the excessive foaming which occurred between " 120 and 170°C. This resulted in losses of oil through physical carry over with distillate. However, provided the catalyst level was kept at approximately 6% on the weight of oil, clarification was achieved when the temperature was raised in excess of 345 °C (Run 2). In other words,
  • Table 1 shows that the three different used oils all respond to treatment with the Hy Pow'r catalyst system. These oils foamed to different degrees and some produced oxides of nitrogen and elemental sulfur which came over with the distillate, but all oils examined were clarified by the Hy Pow'r process.
  • Table 2 summarises the results of treating No. 2 oil with different combinations of the Hy Pow'r catalyst system in conjunction with clay. It will be seen that all catalyst combinations cause clarification of the oil, but the combination which contains equal amounts of the three ingredients is preferred. This mixture generates the greatest volume of foam. Since this characteristic indicates that the catalyst is causing coagulation of suspended impurities, it is thought that clarification efficiency is related to the foam volume.
  • Table 3 summarises analytical data on both the raw and re-refined oils. The results show that treatment of all three raw oils converts them into clear pale yellow coloured base stocks. Virtually all contaminant metals are removed along with other suspended materials by the Hy Pow'r process. The re-refined oils have low BS & W values and low total acid numbers. The re-refined oil viscosities all correspond to oils with SAE Nos. of 20 with viscosity indices in the range 109 to 180. The flash points of the products examined range from 189 to 218°C.
  • Table 3 includes lead and zinc levels for the solids recovered on the filter pads. It will be seen that metals removed from the raw oils during treatment are associated with solids removed from re-refined oils by filtration. (No attempts have been made to obtain material balances of metals originally present in the raw oils and subsequently being deposited on the filter pads.
  • the odour is unpleasant and is typical of acid/clay re-refined oils.
  • the viscosity index of 100 is higher than typical Canadian base stocks and this probably indicates that some viscosity index improvers (polymers) remain in the oil. It is almost impossible to completely remove these compounds without total distillation. The presence of these compounds are not necessarily harmful. e.g. a) In formulating multigrade engine oils they would be an advantage in that less VI improver would be needed b) In formulating oils requiring good demulsibility such as turbine oils they would probably be deleterious. Pour Point is a reasonable figure for base oil
  • Acidity is very low. It is comparable with the best acid/clay re-refined oils and better than most. It is close to the figure obtained on virgin base stocks. Elemental analysis shows a very good removal of additive metals and contaminants. The only slight remaining material is 9ppm Zinc (down from approximately. lOOOppm in typical used oil).
  • the cleanliness problem is easily remedied by filtering down to 15 microns; preferably using a paper filter.
  • the only superior re-refined oils analysed were all manufactured using a distillation/hydro treating process, i.e. KTI process used in Greece
  • the flashpoint of Shell 100 neutral (SAE 5W) oil is 196°C min. as is the Mohawk SAE 10 oil (Mohawk HT 150).
  • the only oil sold in Canada with a flashpoint as low as 179C is Imperial SAE 5W, and the Imperial SAE 10W is 200 °C min.
  • treated acid activated clay containing 0.1 % pre blended catalyst consisting 0.03% each of MgSO4, Al2(SO4)3 and NaCl, respectively.
  • the treated clay normally contained about 14-15% moisture.
  • the percentage clay used is based on undried weight and untreated oil basis:
  • EXAMPLE 4 In the experiment, lOOOg of untreated oil was added lOg of water and 200g of "treated acid activated clay" heated in a three neck flask equipped with a stirrer under nitrogen purge to 370°C for lOmin.
  • the dark black untreated oil contains 1192, 774, 550, 579, 64, 30, 43, 134, 40, 25, 9, 813 and 400ppm of Ca, Zn, Mg, P, Ba, B, Cu, Fe, Si, Al, Cr, Pb, and Na metal ion impurities.
  • about 150g water, 136g of gas oil and 734g of lube oil were collected.
  • the lube oil yield was about 73% with an ASTM colour of 3-3.5 and a TAN of 0.03.
  • the metal impurities were all reduced to lower than 1 ppm except Ca, Si and Na which were 2.8, 59.8 and 1.2 ppm, respectively.
  • Viscosity 35.93 CS (40°C); 6.03 CS (100°C) Viscosity Index: 112
  • Viscosity at 100°C is 49.0 SUS (6.97 cst).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

Procédé permettant de raffiner une nouvelle fois l'huile lubrifiante usée pour en permettre la réutilisation en tant que lubrifiants de haute qualité. Il consiste: a) à mélanger l'huile à un catalyseur contenant un composé inorganique et de la terre activée acide du type de la montmorillonite, puis à chauffer et à agiter le mélange pendant une période et à une température prédéterminées afin d'en provoquer de manière sélective le craquage; b) à réduire la température et à poursuivre l'agitation pendant une période suffisante pour achever la réaction; c) à refroidir le reste et à le filtrer pour séparer l'huile propre du mélange. On décrit également un dope comportant des composés inorganiques et des terres et servant à rendre inactifs les contaminants.
PCT/AU1992/000172 1991-04-17 1992-04-16 Enlevement des contaminants de l'huile lubrifiante usee WO1992018590A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPK5699 1991-04-17
AUPK569991 1991-04-17

Publications (1)

Publication Number Publication Date
WO1992018590A1 true WO1992018590A1 (fr) 1992-10-29

Family

ID=3775347

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1992/000172 WO1992018590A1 (fr) 1991-04-17 1992-04-16 Enlevement des contaminants de l'huile lubrifiante usee

Country Status (1)

Country Link
WO (1) WO1992018590A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2065857A1 (es) * 1993-08-02 1995-02-16 Iscu S A Sistema para la eliminacion del aceite usado de los vehiculos automoviles.
US20100230357A1 (en) * 2009-03-13 2010-09-16 Woodrising Resources Ltd. Method for Removal of Volatile Phosphates From Hydrocarbons
US8197675B2 (en) 2003-08-01 2012-06-12 Wilmer Lee Briggs Process for removing contaminants from hydrocarbon obtained from recycled materials
CN101768505B (zh) * 2010-02-08 2012-08-08 长安大学 废发动机油絮凝吸附再生处理方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB228162A (en) * 1924-01-20 1925-12-24 Joseph Dreyfus Process for purifying oils which have been used for lubricating internal combustion and like engines
US3098031A (en) * 1958-09-30 1963-07-16 Harris Velma Claver Method of re-refining
US4151072A (en) * 1977-05-16 1979-04-24 Phillips Petroleum Company Reclaiming used lubricating oils
GB1594879A (en) * 1977-06-20 1981-08-05 Borenstein L Process for treating waste oil
GB2099847A (en) * 1981-06-08 1982-12-15 Phillips Petroleum Co Reclaiming used lubricating oil
US4383915A (en) * 1980-05-06 1983-05-17 Turbo Resources Ltd. Clay contacting process for removing contaminants from waste lubricating oil
US4411774A (en) * 1981-01-16 1983-10-25 Turbo Resources Ltd. Process for removing contaminants from waste lubricating oil by chemical treatment
US4502948A (en) * 1984-03-30 1985-03-05 Phillips Petroleum Company Reclaiming used lubricating oil

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB228162A (en) * 1924-01-20 1925-12-24 Joseph Dreyfus Process for purifying oils which have been used for lubricating internal combustion and like engines
US3098031A (en) * 1958-09-30 1963-07-16 Harris Velma Claver Method of re-refining
US4151072A (en) * 1977-05-16 1979-04-24 Phillips Petroleum Company Reclaiming used lubricating oils
GB1594879A (en) * 1977-06-20 1981-08-05 Borenstein L Process for treating waste oil
US4383915A (en) * 1980-05-06 1983-05-17 Turbo Resources Ltd. Clay contacting process for removing contaminants from waste lubricating oil
US4411774A (en) * 1981-01-16 1983-10-25 Turbo Resources Ltd. Process for removing contaminants from waste lubricating oil by chemical treatment
GB2099847A (en) * 1981-06-08 1982-12-15 Phillips Petroleum Co Reclaiming used lubricating oil
US4502948A (en) * 1984-03-30 1985-03-05 Phillips Petroleum Company Reclaiming used lubricating oil

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2065857A1 (es) * 1993-08-02 1995-02-16 Iscu S A Sistema para la eliminacion del aceite usado de los vehiculos automoviles.
US8197675B2 (en) 2003-08-01 2012-06-12 Wilmer Lee Briggs Process for removing contaminants from hydrocarbon obtained from recycled materials
US20100230357A1 (en) * 2009-03-13 2010-09-16 Woodrising Resources Ltd. Method for Removal of Volatile Phosphates From Hydrocarbons
US8636905B2 (en) * 2009-03-13 2014-01-28 Woodrising Resources Ltd. Method for removal of volatile phosphates from hydrocarbons
US9011692B2 (en) 2009-03-13 2015-04-21 Skye Petroleum Inc. Method for removal of volatile phosphates from hydrocarbons
CN101768505B (zh) * 2010-02-08 2012-08-08 长安大学 废发动机油絮凝吸附再生处理方法

Similar Documents

Publication Publication Date Title
US4512878A (en) Used oil re-refining
US4151072A (en) Reclaiming used lubricating oils
CA1100078A (fr) Methode de preparation d'huile lubrifiante a partir d'huile de lubrification epuisee
CA1079215A (fr) Traitement thermique des huiles minerales usees
US4502948A (en) Reclaiming used lubricating oil
US4250021A (en) Treating used hydrocarbon lubricating oils
US3879282A (en) Reclaiming used motor oil by chemical treatment with ammonium phosphate
EP0033546A1 (fr) Procédé de séparation de produits de contamination formant des cendres, d'une huile usée et procédé pour traiter l'huile usée
US4411774A (en) Process for removing contaminants from waste lubricating oil by chemical treatment
US4383915A (en) Clay contacting process for removing contaminants from waste lubricating oil
CZ20011559A3 (cs) Způsob zpracování pouľitých olejů
CA1144100A (fr) Decendrage des huiles lubrifiantes
RU2107716C1 (ru) Способ и установка для регенерации смазочных масел
US6174431B1 (en) Method for obtaining base oil and removing impurities and additives from used oil products
CN1107109C (zh) 一种废油的回收方法
US20080070816A1 (en) Process for recovering used lubricating oils using clay and centrifugation
US4431523A (en) Upgrading fuel fractions in a re-refined oil process
WO1992018590A1 (fr) Enlevement des contaminants de l'huile lubrifiante usee
CA1209512A (fr) Epuration-regeneration des huiles epuisees
US3904512A (en) Method for reclaiming used crankcase oil
CA1107673A (fr) Recyclage des huiles lubrifiantes epuisees
GB2099847A (en) Reclaiming used lubricating oil
EP0077564A2 (fr) Enlèvement de cendres d'huiles lubrifiantes
US5458765A (en) Process of drying and removing solids from waste oil
US2114314A (en) Process of treating oils and distillates thereof

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT AU BB BG BR CA CH CS DE DK ES FI GB HU JP KP KR LK LU MG MN MW NL NO PL RO RU SD SE US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE BF BJ CF CG CH CI CM DE DK ES FR GA GB GN GR IT LU MC ML MR NL SE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA