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
  • C10M175/0016—Working-up used lubricants to recover useful products ; Cleaning with the use of chemical agents
• • 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
  • C10M175/0025—Working-up used lubricants to recover useful products ; Cleaning by thermal processes
• • 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
  • C10M175/02—Working-up used lubricants to recover useful products ; Cleaning mineral-oil based

Definitions

• the present invention relates to a process for refining used oils which makes it possible to obtain refined oils which can be reused in particular as base oil, as fuel, or in an oil refinery.
• oils is understood to mean an oil or a mixture of oils in variable proportions, of various origins originating in particular from industrial applications.
• oils intended for industrial uses or for engines contain various additives intended to give them the specific properties required for the envisaged applications.
• additives are either organic (so-called “ashless” additives) or organometallic.
• ashless additives organic additives
• organometallic organometallic.
• base oils hydrocarbons having boiling points higher than 350 ° C
• thermal stability as high as possible
• volatility as low as possible.
• Oils after use or used oils contain as additives such as impurities, either intact or in the form of decomposition products as well as sediments (wear particles from moving metal parts, air dust, carbon, etc.) and hydrocarbons not present in the original oils and which are undesirable.
• impurities either intact or in the form of decomposition products as well as sediments (wear particles from moving metal parts, air dust, carbon, etc.) and hydrocarbons not present in the original oils and which are undesirable.
• These gasoline and diesel fractions, oxidation products (such as organic acids) and pyrolysis products. The presence of these various impurities makes it particularly difficult to refine used oils.
• Chlorine content (mg / kg) 150-2000
• the phosphorus and silicon contents were measured by plasma, the chlorine contents either by X-ray fluorescence (above 50 mg / kg) or by coulometry (below 50 mg / kg), the acid number was determined according to French standard NFT 60112, the viscosity was measured at 40 ° C according to the NFT 60100 method, the color was measured according to the ASTM D 1500 method, the odor was measured from sensory by the experimenter and the saponification index was measured by potentiometry.
• oils are obtained which are entirely unsuitable for use as a base oil for formulating new lubricants.
• the alkaline treatments applied to used oils before their vacuum distillation although they effectively reduce the odor and the acidity of the resulting oils, do not, however, quantitatively eliminate undesirable contaminants such as chlorine, taking into account the conditions under which alkaline agents are used.
• oils thus pretreated, they can be refined according to various processes, in particular by catalytic hydrogenation at high pressure, or by treatment with concentrated sulfuric acid, by treatment with an activated earth or by the combination of these last two treatments. and in some cases by distillation after one of these treatments.
• High pressure catalytic hydrogenation cannot, however, be used without raising catalyst deactivation problems if the oils subjected to this type of treatment are not rigorously free of contaminants such as phosphorus, chlorine and silicon.
• Treatment processes based on sulfuric acid / activated earth cause the production of acidic sludge and used earth which is difficult to absorb.
• the present invention thus relates to a process for refining used oils which makes it possible to obtain refined oils capable of meeting the various criteria of quality and purity set out above, this process being characterized in that it comprises a determined series of steps consisting of: a) distilling said used oils, b) treating the resulting distillate with an alkaline agent and in the presence of a solvent chosen from water, a monoalcohol, a polyalcohol and a mixture of these alcohols, said alkaline agent being present in a proportion, in percentage by weight relative to the weight of the distillate, equal to the product F x (IA + IS), F being a multiplying factor of between 2 and 50, IA and IS being respectively the acid number and the saponification number of the distillate, said treatment being carried out at a temperature of approximately 80 to 330 ° C and for a time of approximately 2 to 200 min, c) to be washed with water the reaction medium and then leave to settle to recover the oily phase, and d) to carry out the distillation of said oil
• the method according to the invention has the particular advantage of being very flexible in so far as it can be adapted, as regards its characteristics, to the required quality of the finished products.
• the process according to the invention can be implemented following one or more prior treatment processes, physical and / or chemical, and / or upstream of one or more refining processes, such as than those mentioned above.
• the distillation step (a) is firstly carried out under atmospheric pressure, at a temperature of approximately 130 to 180 ° C., to remove the water and recover a fraction of essences.
• the distillation is then continued, under a pressure of about 650 to 12,000 Pa and at a temperature of about 240 to 345 ° C, to recover a small fraction of diesel and then a large fraction, greater than 60% of the used waste oil.
• the whole of the distillate can be subjected to the subsequent step, the only significant fraction of the distillate is preferably used according to the invention.
• This prior distillation step is particularly important because it allows almost all of the tars to be removed.
• the alkaline agent used in step (b) of the process is either soda or potash, but never a mixture of soda and potash.
• potash is used according to the invention.
• the pH of the reaction medium is greater than 8 and preferably between 9.5 and 13.
• the concentration of the alkaline agent in aqueous solution is preferably between 50 and 96% by weight relative to the weight of the aqueous solution.
• the aqueous solution of alkaline agent is in the form of the potassium / water eutectic (86.7 / 13.3).
• the aqueous solution of alkaline agent is prepared beforehand and is then added with continuous stirring to the distillate resulting from step (a). It can be "solid" at room temperature, as is notably the case for the potassium / water eutectic (86.7 / 13.3), the use of which constitutes a particularly preferred embodiment. In this case, the "solid" solution becomes fluid at the reaction temperature.
• the alcoholic solution used is preferably such that the molar ratio of said solvent to said alkaline agent is between 2 and 20, and more particularly between 2.5 and 5.
• an amount of alcohol or an alcohol mixture sufficient to ensure in the reaction medium a concentration of alkaline agent close to saturation is used.
• the monoalcohol or the polyalcohol preferably contains from 2 to 8 carbon atoms, and more particularly from 2 to 5 carbon atoms.
• the monoalcohols preferred according to the invention mention may be made of ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, isobutanol, pentanols, hexanols and octanols.
• the preferred polyalcohols according to the invention mention may be made of ethylene glycol, di- and tri-ethylene glycol. It is preferred, according to the invention, to use alcohols having a boiling point lower than the initial boiling point of the distillate and / or having a high solubility in water since their subsequent elimination by distillation or washing with water is easier.
• the reaction medium is preferably prepared either by dissolving the alkaline agent in alcohol, then introducing it into the distillate, or by hot mixing the distillate and the alcohol then adding the alkaline agent in the form of solid pellets.
• step (b) of the process according to the invention when an alcohol or a mixture of alcohols is used as solvent, the distillate is treated with the alkaline agent at reflux of alcohol or mixture of alcohols, however, provided there is no risk of loss by evaporation.
• step (b) of the process according to the invention when operating at high temperature, and in particular when the solvent comprises an alcohol with a boiling point below the reaction temperature chosen, the distillate is treated with the alkaline agent at a pressure of about 10 5 to 50 x 10 5 Pa, preferably under a pressure of 10 5 to 25 x 10 5 Pa, in order to avoid losses by evaporation.
• At least one washing of the reaction medium is carried out using 1 to 15% of water approximately at a temperature between ambient temperature and approximately 100 ° C.
• the washing operation with water or step (c) of the process according to the invention makes it possible to remove the excess of alkaline agent, possibly the alcohol if it has been used as solvent as well as all the products soluble from contaminants and generated by alkaline treatment.
• the washing step is carried out in two separate operations.
• the first consists in treating the reaction medium obtained after step (b) with an amount of water of approximately 1 to 10% and at a temperature as low as possible, between 20 and 90 ° C.
• the second is, after decanting, treating the reaction medium again with an amount of water of between 1 and 10% and at a temperature as high as possible and at least equal to that of the first operation.
• the temperature should preferably be as low as possible so as to minimize the hydrolysis phenomena but sufficient to lower the viscosity of the oily reaction medium of step (b) and guarantee a sufficient decantation speed .
• the temperature should be as high as possible in order to ensure good removal of the residual alkaline agent.
• the total amount of water used according to this particular embodiment is preferably between 5 and 15%.
• the second washing operation can be carried out using a weakly acidic aqueous solution, for example using 0.1 to 1 N hydrochloric acid.
• washing and decanting step of the oily phase this is then subjected to the distillation step (d) consisting first of all of a distillation at atmospheric pressure and at a temperature of about 70 to 270 ° C, to remove any remaining solvent, then at a pressure of about 1350 to 650 Pa and at a temperature of about 210 to 375 ° C in order to obtain a refined oil and a residue which represents less than 5% of the charge of departure.
• step (c) of washing the oily phase with water can be followed by at least one treatment of said oily phase by catalytic hydrogenation at high pressure, by contacting with a sulfonating agent and / or by contacting with activated carbon or an activated earth.
• the sulfonating agent is chosen from concentrated sulfuric acid and chlorosulfonic acid.
• the activated earth is preferably a mineral earth of the silico-aluminate type activated by an acid treatment.
• this treatment is preferably followed by neutralization of the oily phase, for example by adding the washing water from step (c) and preferably by addition of ammonia.
• the refined oil or the base oil obtained by the process according to the invention has excellent properties, both physical and chemical. It is practically free of odor, of low coloring and has very low chlorine contents, but also phosphorus and silicon
• Chlorine content (mg / kg) ⁇ 35
• the treatment process according to the invention is particularly effective in reducing the main contaminants of used oils
• the distillation residue represented approximately 18.5% and consisted mainly of tars.
• the fraction representing 65% had the following characteristics:
• distillate fraction representing approximately 65% was treated under the conditions given in Table V below using an aqueous potassium hydroxide solution.
• the pure potash to be used to achieve the result is 7.2% or about 45 times the stoichiometry (IA + IS) if an aqueous potassium solution of 50% and 0 is used. , 47% or about three times the stoichiometry if the potassium / water eutectic is used.
• the treatment temperature is much lower since it is 220 ° C instead of 300 ° C.
• step (b) of the alkaline treatment of the process according to the invention was carried out at temperatures varying between 175 and 300 °. C for a period of 10 to 60 minutes with n-octanol under the conditions indicated in Table VI below.
• the amount of alkaline agent used was in all cases at least equal to twice the stoichiometry (IA + IS) and all the tests according to these examples were carried out under atmospheric pressure with the exception of examples 10 and 11 which were carried out under a pressure of 10 ⁇ 10 5 Pa.
• Saponification index (IS; mgKOH / g) 2.90
• Half of the distillate was treated with 2.5% 85% potash (i.e. 2% dry potash) and the other half was treated with 4.71% 85% potash (i.e. 4% dry potash) ).
• the treatments were carried out at a temperature of 250 ° C for approximately 30 minutes.
• the first half resulting from the treatment with 2% dry potash was divided into two equal parts.
• the first was subjected to a single washing with 10% water at 100 ° C, and the second to the following two washing operations:
• the first was subjected to a single wash using 10% water at 100 ° C, and the second to the following two washing operations: (i) a first wash using 5% water at 65 ° C and after decantation at
• washing in two operations leads to oils having a markedly improved color, which is a particularly unexpected result.

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Fats And Perfumes (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Lubricants (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

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• 1995
  • 1995-06-22 FR FR9507484A patent/FR2735785B1/fr not_active Expired - Fee Related
• 1996
  • 1996-06-21 EP EP96924004A patent/EP0835298B1/de not_active Expired - Lifetime
  • 1996-06-21 CA CA002222704A patent/CA2222704A1/fr not_active Abandoned
  • 1996-06-21 WO PCT/FR1996/000974 patent/WO1997000928A1/fr active IP Right Grant
  • 1996-06-21 US US08/981,749 patent/US6072065A/en not_active Expired - Fee Related
  • 1996-06-21 AT AT96924004T patent/ATE201438T1/de not_active IP Right Cessation
  • 1996-06-21 DK DK96924004T patent/DK0835298T3/da active
  • 1996-06-21 DE DE69612978T patent/DE69612978T2/de not_active Expired - Fee Related
  • 1996-06-21 ES ES96924004T patent/ES2125208T3/es not_active Expired - Lifetime
• 1997
  • 1997-12-19 NO NO976008A patent/NO976008L/no not_active Application Discontinuation

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