FR3039162A1 - OIL PURIFICATION AND ANTI-WEDDING ADDITIVE PREPARATION - Google Patents

Abstract

The invention relates to the field of purification of hydrocarbon feeds comprising one or more compounds to be removed, in particular used lubricating compositions. The invention also relates to a rutting resistance additive for bitumen prepared according to a process for purifying a hydrocarbon feedstock, comprising one or more compounds to be eliminated and a purified oil whose viscosity ranges from 50 to 400 mm 2. s-1.

Description

OIL PURIFICATION AND PREPARATION OF ANTI-ORNERING ADDITIVE DESCRIPTION

The invention relates to the field of purification of hydrocarbon feeds comprising one or more compounds to be removed, in particular used lubricating compositions. The invention also relates to a rutting resistance additive for bitumen prepared according to a process for purifying a hydrocarbon feedstock, comprising one or more compounds to be eliminated, as well as a purified oil whose viscosity ranges from 50 to 400 mm. .s V

In use, the lubricating compositions are degraded and then comprise pollutant compounds, undesirable or to be eliminated. Thus, used oils, such as motor oils, hydraulic oils, gear oils or industrial oils and mixtures thereof, must be purified to regenerate them into a lubricating base of commercial quality identical to the original product. for a new use. This type of treatment may be referred to as the re-refining or regeneration of waste oils. The field of the invention is therefore that of the regeneration of hydrocarbon feedstocks, such as waste or used oils, in particular engine oils, hydraulic oils, gear oils or industrial oils, and mixtures thereof. The invention also makes it possible to produce substances that can be reused according to their properties obtained from the purification of used oils.

During their use, the oils are subjected to stresses that will cause their degradation leading to an increase in the level of contaminating elements these oils, these contaminants may be derived from a degradation of the additives present in the lubricant compositions, such as the antioxidant additives, antiwear agents; or external pollutants, such as dust; or wear metals emanating from, for example, parts with which the oil is in contact during use; or even fractions of fuel (gas oil or gasoline) more or less oxidized or thermally cracked and which may be in liquid or solid form including soot; or else contaminants related to the storage of used oils in which there are sometimes substances constituting light fractions which are generally water or chlorinated or petroleum solvents.

This results in a polluted oil with a stronger coloration than the original clean oil, hence the name of black oils in the field of waste oils, in particular because of the presence of oxidation products or cracking fuel. In order to be reusable, the oil must be freed from these contaminants and, for this purpose, is required to undergo depollution operations generally similar to those of refining.

Methods are known for purifying used oils or waste oils. However, these methods have disadvantages and are therefore not satisfactory. In particular, the known processes do not make it possible to valorize all the products resulting from the purification of used oils or during the purification of used oils.

In addition, these processes require large deposits of used oils and are not suitable for small territories or isolated territories. The invention thus provides a method for providing a solution to all or part of the problems of the methods of the state of the art. The invention relates to a process for purifying a hydrocarbon feedstock comprising one or more compounds to be eliminated, which comprises the successive steps of: a) extracting light compounds present within the feedstock; b) filtering the compounds to be removed, in the presence of a fluid in the supercritical state; c) separating the retentate comprising compounds to be removed and treating the filtered feed with a transformation agent; d) separating the purified hydrocarbon feedstock by distillation under vacuum or under reduced pressure and separating the distillation residue; e) washing the distillation residue with an aqueous solution; f) separating the aqueous phase and the organic phase from the washed distillation residue.

Advantageously, the process according to the invention applies to a hydrocarbon feedstock chosen from a mineral or mineral oil or a synthetic or synthetic oil. Preferably, the hydrocarbon feedstock is chosen from mineral oils resulting from the fractional distillation of crude oil, in particular industrial oils, gear oils, hydraulic oils or used or used motor oils. Generally, the hydrocarbon feedstock treated according to the process of the invention comprises one or more hydrocarbons and optionally one or more compounds comprising carbon atoms, hydrogen and which may also comprise one or more heteroatoms. Generally, the hydrocarbon feedstock treated according to the process of the invention also comprises compounds to be eliminated selected from dispersant additives, detergent additives, anti-wear additives, polymers, soot, metal elements.

Preferably, the extraction (a) of the light compounds is carried out by distillation under vacuum or under reduced pressure. Advantageously, the extraction (a) is a flash evaporation of the light compounds. Extraction (a) of the process according to the invention also makes it possible to separate the water or the aqueous phase which may be present within the hydrocarbon feedstock. Extraction (a) is especially carried out at a pressure of less than 0.08 bar, for example less than 0.05 bar, or even less than 0.03 bar. Generally, the extraction (a) is carried out at a temperature ranging from 100 to 250 ° C, for example at about 150 ° C.

According to the invention, the filtration (b) in the presence of a fluid in the supercritical state is preferably implemented by means of CO2 in the supercritical state although other gases, such as N2O, SFe, methane , ethane, propane or hexane, may be suitable. During filtration (b), the CO2 in the supercritical state is generally used in an amount ranging from about 2 to 60% or about 15 to 20% by weight of hydrocarbon feedstock to be purified.

In a preferred manner for the process according to the invention, the filtration (b) is a tangential filtration. Also preferably for the process according to the invention, the filtration (b) is carried out at a temperature ranging from 100 to 180 ° C. or at a pressure ranging from 120 to 180 bar. It can be carried out at a temperature ranging from 100 to 180 ° C. and at a pressure ranging from 120 to 180 bar.

Filtration (b) of the compounds is carried out by means of a filter which may be a membrane based on metals or metal alloys such as steel, for example stainless steel, or nickel; of oxides such as oxides chosen from Al 2 O 3, ZrO 2, TiO 2. Filtration (b) concerns the majority of the compounds to be removed, preferably 80% or even 90% or more of the compounds to be removed are filtered. Advantageously, the filter makes it possible to retain compounds or particles whose average size, ie the mean particle diameter, ranges from 1 nm to 10 μm, preferably from 2 nm to 1 μm, and more preferred from 2 nm to 0.1 μm.

Filtration (b) makes it possible to separate the compounds to be eliminated present in the filtration retentate from the filtered hydrocarbon feedstock. The filtered hydrocarbon feedstock is then treated using the transformation agent.

Advantageously, the retentate comprising compounds to be eliminated can be concentrated. This concentration of the retentate can be achieved by eliminating certain compounds, in particular paraffinic compounds.

In a preferred manner, the treatment (c) of the feedstock by means of a transformation agent is carried out by saponification. Preferably, the treatment (c) by saponification is carried out using a transformation agent chosen from NaOH or KOH, used alone or as a mixture. The saponification is preferably carried out using NaOH.

Distillation (d) is vacuum distillation, for example, falling film vacuum distillation or thin-layer distillation under reduced pressure. When performing a falling film distillation, the start distillation parameters are advantageously about 19mbar for the pressure, about 240 ° C for the medium temperature and about 50 ° C for the temperature at the top of the column. At the end of distillation, these parameters are generally about 19mbar for the pressure, about 375 ° C tending towards 400 ° C for the temperature of the medium and about 375 ° C for the temperature at the top of the column.

Distillation (d) makes it possible to separate fractions whose characteristics are identical to base oils. These fractions can therefore be used as base oil in lubricating compositions.

During washing (e), the distillation residue is treated with an aqueous solution. Preferably, the washing (e) is carried out with water, for example in an amount ranging from 1 to 5 times, preferably from 1 to 3 times, the volume of distillation residue obtained. The mixture of the aqueous phase and the distillation residue can be stirred.

Washing (e) can be carried out with varying amounts of aqueous solution. A mixture comprising 20, 30 or 50% by weight of distillation residue supplemented to 100% by weight with aqueous solution may be advantageous.

After washing (e), the aqueous phase and the washed organic phase are separated. The separation can be carried out by decantation. Once the organic phase is separated, it can be dried. Advantageously, its viscosity, measured at 100 ° C. according to the ISO 3104 standard, ranges from 50 to 400 mm, preferably from 100 to 200 mm.

The particular or preferred features of the method according to the invention can be combined with each other in ways to define variants of the method according to the invention. In particular, the specific combinations of the preferred characteristics define preferred variants of the process according to the invention. Preferably, the process according to the invention comprises the following steps: a) extracting by distillation under vacuum or under reduced pressure, light compounds present in the hydrocarbon feedstock comprising one or more compounds to be eliminated; b) filtering the compounds to be removed tangentially in the presence of CO2 in the supercritical state; c) separating the retentate comprising compounds to be removed and treating the load filtered with soda in aqueous solution at about 50% by weight; d) separating the transformed compounds from the purified hydrocarbon feedstock by distillation under vacuum or under reduced pressure and separating the distillation residue; e) washing the distillation residue with an aqueous solution; f) separating the aqueous phase and the organic phase from the washed distillation residue.

Moreover, the process according to the invention can be carried out in an installation comprising at least: a first unit, for example a tank, in which the hydrocarbon feedstock to be purified is placed; A filtration unit connected to the first unit; and a retentate collection unit and a filtrate collection unit both connected to the filtration unit.

In a particularly advantageous manner, the process according to the invention makes it possible to purify a hydrocarbon feedstock comprising one or more compounds to be eliminated and to obtain a purified hydrocarbon feedstock. Preferably, this purified hydrocarbon feed can be used as a lubricant, especially as a vehicle engine lubricant.

Also advantageously, the process according to the invention makes it possible to obtain a filtration retentate. This filter retentate has particularly advantageous properties. Thus, the invention also relates to the use of this retentate prepared as a bitumen additive. Preferably, it is a rutting resistance additive for bitumen. The invention also relates to the use of the filter retentate for the preparation of a road coating composition comprising at least one bitumen and this additive, preferably in an amount ranging from 1 to 10% by weight of composition. The bitumen can in particular be a 35/50 grade bitumen.

During the preparation of a composition comprising at least one 35/50 grade bitumen and additive obtained according to the invention, it is possible to obtain an additive bitumen of class 50/70.

Also advantageously, the process according to the invention makes it possible to obtain an organic phase of the washed distillation residue. According to the invention, this organic phase of the distillation residue can advantageously be used as a lubricant, preferably as a lubricant for gears, for example for open gears. This lubricant has a viscosity measured at 100 ° C. according to the ISO 3104 name ranging from 50 to 400 mm, preferably from 100 to 200 mm.

The various aspects of the invention are illustrated by the following examples.

Example:

A mixture of used oils from motor oils, bridge oils and gearbox oils (5000 L) from heavy vehicles was processed according to the process of the invention. The waste oil mixture is placed in a jacketed tank which is heated to 70 or 80 ° C and then heated by means of an exchanger (150 ° C). The water in the used oil mixture is removed by flash distillation (150 ° C, 150 mbar) in a 50 L autoclave. The remaining light substances are then separated from the oil mixture at the same time. flash evaporation.

The waste oil mixture (4,600 L) from the distillation is then filtered in the presence of supercritical CO2 (150 ° C, 150 bar) in an amount of about 20% by weight of the amount of used oils entering the device.

Fifteen microfiltration membranes (product Tami Dahlia 0.14 pm) are arranged in a recirculation loop equipped with a centrifugal pump of large volume capacity. The injection of the used oil - CO2 mixture is made in the suction line of the centrifugal pump to maximize the mixing of the two components before filtration. The waste oil flow in the plant is 165 kg / h. The flow rate of the filtrate is about 125 kg / h. The difference between inner and outer pressures of the filtration membranes (ΔΡ) is less than 4 bar. A filtrate (2870 L) and a filtration retentate (1550 kg) are obtained.

The filtration retentate is reintroduced into the filtration loop. The treatment conditions are similar (150 ° C., 150 bar). The qrantity of CO2 is about 30% by mass of retentate introduced. The recirculation rate is about 30-31 m 2 / hr. The charge rate is 50 kg / h and the retentate flow rate is about 43 kg / h.

The filtrate obtained during this reprocessing is mixed with the filtrate obtained during the filtration of the used oil mixture.

A total of 1,487 L filtrate and a filtration retentate (217 kg) are obtained. A retentate is obtained whose density mixed with CO2 is about 982 kg / m 2 (about 300 kg / m 2 in mixture with CO2).

The physico-chemical characteristics of the used oil mixture, the retentate and the filtrate are presented in Table 1. The amounts (A in mg), concentration (B in% by weight) and abatement (C in% by weight) of the different chemical elements are also presented in Table 1.

Table 1

A filtrate (2870 L) is obtained which is treated with sodium hydroxide (4% by weight relative to the amount of filtrate) in solution in water (4% by weight relative to the amount of filtrate) for 15 hours. hours, at a temperature of 100 ° C.

Then, the mixture is distilled at reduced pressure (50 mbar) at 290 ° C using a thin-film evaporator equipped with rigid scrapers.

Flash evaporation is then carried out (5 mbar) followed by distillation (5 mbar and 315 ° C.). A purified oil and a distillation residue are obtained. The purified oil obtained after distillation is analyzed and compared with two commercial oils (a refined base oil and a regenerated base oil): Infra-red spectrometers, elemental analysis and metal contents, elemental analysis: carbon, hydrogen, sulfur, nitrogen, oxygen, metals and metalloids, technical characteristics: color, viscosity (several determinations at various temperatures), pour point, flash point, Conradson residue, water content, acid number, iodine number, point of aniline, simulated and real distillation of hydrocarbons, density.

The characteristics and the properties of the purified oil obtained according to the invention are presented in Table 2.

Table 2

The contents of polycyclic aromatic hydrocarbon compounds (PAHs) were analyzed by chromatography (HPLC and detection in UV-fluorimetry). They were compared with those obtained by analysis of a regenerated oil according to a method of the state of the art (oil EH). The results are shown in Table 3.

Table 3

The characteristics and properties of the purified oil obtained according to the invention are equivalent to or greater than those of the two oils. The base oil according to the invention can therefore be used in a lubricant composition, especially in a lubricant composition for a vehicle engine.

The distillation residue obtained after distillation was washed with water with stirring for 4 hours and then the organic phase was separated by decantation for 12 hours. A paraffin oil is obtained whose viscosity measured at 100 ° C. is 150 minutes. This oil can be used to lubricate gears, especially open gears.

In addition, the filtration retentate was evaluated for its bitumen additive properties. The retentate is mixed with bitumen and its resistance properties within the mixture as well as the improvement of the properties of the additive bitumen were analyzed.

The program is established in two phases. The first concerns the behavior of the mixture of retentate and bitumen, before and after simulation of a coating. The measures are based mainly on the assessment of the consistency of the products, in accordance with the European regulatory specifications. The second phase deals with the coated material, made by mixing aggregates, bitumen and retentate. The compactibility, water stripping resistance and ability to resist rutting are evaluated.

The bitumen class chosen is 35/50. The rate of modification of the bitumen by the retentate was set at 2.5% by weight.

Complex modulus measurements show that the retentate and bitumen mixture is rheologically simple. This reflects a good compatibility of the two materials.

This bitumen-type asphalt, made with a 35/50 bitumen additive containing 2.5% by weight of retentate, complies with the level 2 specifications (for a Class 4 GB).

The mixture 35/50 bitumen and retentate (2.5% by weight) complies with the specifications of road bitumens and gives a gravel bitumen of class 4 compliant up to level 2.

A leaching test according to standard NF EN 12 457-2 has also been carried out. A 35/50 bitumen sand was compared to the same 35/50 bitumen sand additive with 2.5% retentate. The analysis of the eluate after leaching test shows a total organic carbon content (according to NF EN 1484) of 17 mg / kg for the reference sample and 31 mg / kg for the sample made from bitumen additive.

Both samples have a similar chromatographic profile free of semi-volatile organic molecules detectable by this technique. As a result, the addition of ultrafiltration retentate to the bitumen does not alter its behavior on contact with water: no semi-volatile substance is detectable in the leachate.

A demixing resistance test was carried out for the additive bitumen of the retentate according to the invention.

The retentate mixed with the bitumen was placed in a vertical tube and then allowed to stand for 36 hours at 180 ° C. After cooling, the softening points of the mixture from the top and bottom of the tube were measured. Softening temperatures of 51.8 ° C. are obtained for the mixture coming from the upper part and 51.4 ° C. for the mixture coming from the upper part.

These very close temperatures confirm that no demixing took place. The additive bitumen of the retentate according to the invention is therefore storage stable.

The resistance to rutting of the additive bitumen of the retentate according to the invention was evaluated by means of a Gamma bank according to the method NF EN 12697 part 22.

The rutting results are very good for the additive bitumen of the retentate according to the invention. Indeed, while the average normative value of the rut depth after 10,000 passes must be less than 10%, the bitumen additive of the retentate according to the invention allows a value of 4.6%.

Claims (12)

A process for purifying a hydrocarbon feedstock, comprising one or more compounds to be removed, which comprises the following steps: a) extracting light compounds present within the feedstock; b) filtering the compounds to be removed, in the presence of a fluid in the supercritical state; c) separating the retentate comprising compounds to be removed and treating the filtered feed with a transformation agent; d) separating the purified hydrocarbon feedstock by distillation under vacuum or under reduced pressure and separating the distillation residue; e) washing the distillation residue with an aqueous solution; f) separating the aqueous phase and the organic phase from the washed distillation residue. 2. Method according to claim 1 wherein the hydrocarbon feedstock is selected from a mineral or mineral oil or a synthetic oil or synthetic origin, preferably selected from mineral oils from the fractional distillation of crude oil, including industrial oils, gear oils, hydraulic oils or used or used motor oils; or comprises one or more hydrocarbons and optionally one or more compounds comprising carbon atoms, hydrogen and which may also comprise one or more heteroatoms. 3. Method according to one of claims 1 and 2 for which the compound or compounds to be removed are selected from dispersant additives, detergent additives, antiwear additives, polymers, soot, metal elements. 4. Method according to one of claims 1 to 3, the extraction (a) of the light compounds is carried out by distillation under vacuum or under reduced pressure. 5. Method according to one of claims 1 to 4, the fluid in the supercritical state, preferably CO2, is present in an amount ranging from about 2 to 60% or about 15 to 20% by weight of hydrocarbon feedstock to be purified. 6. Method according to one of claims 1 to 5, the filtration (b) is a tangential filtration; or carried out at a temperature ranging from 100 to 180.degree. C. at a pressure of from 120 to 180 bar. 7. Method according to one of claims 1 to 6, the treatment (c) of the filler by means of a transformation agent is carried out by saponification, preferably by means of a transformation agent selected from NaOH or KOH, used alone or in a mixture. 8. Method according to one of claims 1 to 7, the retentate comprising compounds to be eliminated is concentrated. 9. Method according to one of claims 1 to 8 comprising the successive steps: a) extracting by distillation under vacuum or under reduced pressure, light compounds present in the load; b) filtering the compounds to be removed tangentially in the presence of CO2 in the supercritical state; c) separating the retentate comprising compounds to be removed and treating the load filtered with soda in aqueous solution at about 50% by weight; d) separating the transformed compounds from the purified hydrocarbon feedstock by distillation under vacuum or under reduced pressure and separating the distillation residue; e) washing the distillation residue with an aqueous solution; f) separating the aqueous phase and the organic phase from the washed distillation residue. 10. Use of a purified hydrocarbon feedstock prepared according to one of claims 1 to 9 as a lubricant, in particular as a lubricant for a vehicle engine. 11. Use of a retentate prepared according to one of claims 1 to 9 as a bitumen additive, preferably as a rutting resistance additive for bitumen; or for the preparation of a road coating composition comprising this additive, preferably in an amount of from 1 to 10% by weight of the composition, and O at least one bitumen. 12. Use of the organic phase of the washed distillation residue, prepared according to one of claims 1 to 9 as a lubricant, in particular as a lubricant whose viscosity measured at 100 ° C according to ISO 3104 is from 50 to 400 mm ^. preferably from 100 to 200 mm for gearing, for example for open gears.