RU2658914C2 - Lubricating oil compositions comprising heavy fischer-tropsch derived and alkylated aromatic base oil - Google Patents

Abstract

FIELD: lubrication compositions.

SUBSTANCE: present invention relates to lubricating compositions containing a Fischer-Tropsch derived extra heavy base oil and an alkylated aromatic blendstock wherein the FT extra heavy base oil has a kinematic viscosity at 100°C in the range from 19 to 35 mm²/s. Also disclosed is a method of making a lubricating composition, which comprises blending a FT derived extra heavy base oil failing the “clear and bright” standard (ASTM D4176) with an alkylated aromatic blendstock to provide a lubricating composition that passes the “clear and bright” standard.

EFFECT: invention relates to lubricating compositions comprising a Fischer-Tropsch derived base oil with waxy haze components, which nevertheless have a clear and bright appearance.

12 cl, 8 tbl, 2 ex

Description

The present invention relates to lubricating compositions containing a particularly heavy base oil obtained using Fischer-Tropsch synthesis. In particular, although not exclusively, the invention relates to lubricating compositions containing a base oil made in the Fischer-Tropsch synthesis, with an admixture of paraffin components, which, however, has a clear and bright appearance.

State of the art

It is known from the prior art that paraffin hydrocarbon feedstocks, including feedstocks made from gaseous components such as CO and H ₂ , especially Fischer-Tropsch synthesis waxes, are suitable for conversion / processing into lubricating base oils, due to the fact that paraffin feed is subjected to hydrogenation dewaxing or hydroisomerization / catalytic (and / or using a solvent) dewaxing; thus, normal long-chain paraffins and slightly branched paraffins are removed and / or rearranged / isomerized into more intensive branching isoparaffins having a lower pour point and cloud point. Lubricating base oils obtained by converting / refining paraffin hydrocarbon feedstocks produced from gaseous components (i.e., Fischer-Tropsch feedstocks) are referred to in the invention as base stocks produced by Fischer-Tropsch synthesis, or simply FT base stocks.

The viscosity of FT base oils can vary significantly. These oils may have a kinematic viscosity at 100 ° C. according to ASTM D445 (KB 100) of at least about 3 mm ² / s (cSt), for example about 5 mm ² / s or about 7 mm ² / s, or about 14 mm ² / s Residual FT base oils having a KB 100 of at least 15 mm ² / s are often referred to in the art as particularly heavy FT base oils. Some particularly heavy FT base oils may have a KB 100 value of at least 17 mm ² / s or at least 20 mm ² / s, or at least 25 mm ² / s.

It is known from the prior art to obtain the so-called residual (or heavy) lubricant base oils produced in the Fischer-Tropsch synthesis, which are hereinafter referred to as “FT Residual Base Oils”. Said residual FT base oils are often especially heavy FT base oils and are obtained from residual (or heavy) fractions resulting from the distillation of at least partially isomerized feed from Fischer-Tropsch synthesis. Before distillation, the at least partially isomerized Fischer-Tropsch synthesis feed may be processed, such as dewaxing. Residual base oil can be obtained directly from the residual fraction, or indirectly during processing such as dewaxing. The residual base oil may not contain a distillate, that is, a side-stream product recovered either from an atmospheric distillation column or from a vacuum column. In documents WO 02/070627, WO 2009/080681 and WO 2005/047439 typical methods for producing residual base oils based on Fischer-Tropsch synthesis are described.

Especially heavy FT base oils, including residual especially heavy FT base oils, are used in a number of lubrication areas due to their excellent characteristics, such as useful viscometric properties and purity. However, these base oils may become undesirable due to paraffin cloudiness at ambient temperature.

The conclusion about paraffin cloudiness can be made or its intensity can be measured in various ways. For example, the presence of paraffin cloudiness can be measured according to ASTM D4176-04, which determines whether a fuel or lubricant meets the transparent and light standard. Although ASTM D4176-04 is written for fuels, it is also applicable for base oils. In addition, the presence or degree of paraffin cloudiness can be quantified as turbidity using nephelometric turbidity units (NTU), for example by measurement, as described in US 2011/0083995.

Paraffin cloudiness in residual FT base oils, which may also undesirably affect the filterability of oils, is caused by the presence of paraffins with a long carbon chain, which is insufficiently isomerized (or cracked).

The content of long carbon chain paraffins that come from paraffinic hydrocarbon feeds is particularly high in the residual fractions from which the residual base oils are made. Since the presence of paraffins with a long carbon chain also leads to relatively high values of pour point and cloud point, usually the residual fractions are dewaxed in the presence of a catalyst and / or solvent in one or more stages. The indicated dewaxing stages are very effective for reducing the pour point and cloud point of the resulting residual FT base oils, and in some conditions can also help reduce or eliminate turbidity, especially in combination with the filtration stage.

However, there is a need for more effective solutions to reduce the clouding of FT base oils, especially for very heavy base oils and residual base oils.

Therefore, the aim of the invention is to solve the problems of paraffin cloudiness of FT base oils or to solve at least one of the problems of the prior art.

The inventors concluded that eliminating paraffin cloudiness in especially heavy Fischer-Tropsch base oils using conventional catalytic dewaxing steps may be ineffective or, in the worst case, inconclusive. Particular difficulties in eliminating turbidity by dewaxing arise in the case of residual especially heavy FT base oils made from heavy paraffinic hydrocarbon feedstocks. Based on this observation, the inventors have developed a new approach regarding the problem of paraffin cloudiness of especially heavy FT base oils.

In a first aspect, the invention relates to a lubricating composition that contains a particularly heavy Fischer-Tropsch base oil and an alkylated aromatic mixed feed in which a particularly heavy FT base oil has a kinematic viscosity at 100 ° C. in the range of 19 to 35 mm / s.

It was found that a particularly heavy Fischer-Tropsch base oil and alkylated aromatic mixed feed have a synergistic effect, provide good lubricating characteristics and stability of the lubricating composition, which reduces the tendency to paraffin cloudiness. It has been established that alkylated aromatic mixed feedstock increases the solubility of paraffin cloudiness in a particularly heavy FT base oil, including in residual especially heavy FT base oils derived from heavy paraffin hydrocarbon feedstocks. A particularly heavy FT base oil significantly improves the lubricity of the composition.

In a second aspect, the invention includes a method for producing a lubricating composition comprising mixing an especially heavy Fischer-Tropsch base oil and an alkylated aromatic mixed feed.

In a third aspect, the invention relates to the use of an alkylated aromatic mixed feed to reduce paraffin cloudiness in a particularly heavy FT base oil, or in a precursor composition that contains a particularly heavy FT base oil. Use may include mixing an alkylated aromatic mixed feed with a particularly heavy Fischer-Tropsch base oil or precursor composition to form a lubricating composition.

In a fourth aspect, the invention relates to a method for reducing paraffin cloudiness in a particularly heavy Fischer-Tropsch synthesis base oil, or in a precursor composition that contains a particularly heavy FT base oil, the method comprising mixing an alkylated aromatic mixed feed with a particularly heavy FT base oil or precursor composition , with the formation of a lubricating composition.

In a fifth aspect, the invention relates to the use of a lubricating composition, which contains a particularly heavy Fischer-Tropsch base oil and an alkyl aromatic mixed feed, for lubricating one or more units: an engine, for example a compression ignition engine, a production plant, such as a compressor, a hydraulic a pump, an industrial turbine, or gearbox, and an energy transmission system.

Additional details and preferred features of the invention are set forth in the following detailed description.

The term “comprising” is used in the invention as a synonym for the term “comprising” and is an open, non-limiting term. However, this term also encompasses the expression “consisting of,” and may be limited by such a definition in embodiments of the invention, where appropriate. To eliminate the ambiguity, preferred and optional features of the invention can be used in every aspect of the invention, where the context allows.

DETAILED DESCRIPTION OF THE INVENTION

A first essential component of the invention is a component of a particularly heavy Fischer-Tropsch synthesis base oil. The expression “especially heavy FT base oil” refers to a hydrocarbon product — a Fischer-Tropsch derived base oil that contains saturated paraffin molecules. Due to the fact that the product is a particularly heavy oil, it usually has a tendency to paraffin cloudiness. A particularly heavy FT base oil can be characterized by one or more of the features described below in the invention, and the expression “especially heavy” is not given any additional limiting technical value.

Typically, a particularly heavy Fischer-Tropsch base oil may contain at least 95 mass. % saturated hydrocarbon molecules. Preferably, a particularly heavy FT base oil is obtained from a Fischer-Tropsch synthesis wax that contains more than 98 wt. % saturated hydrocarbons. Preferably at least 85 mass. %, more preferably at least 90 mass. %, even more preferably at least 95 mass. %, and most preferably at least 98 wt. % of these saturated hydrocarbon molecules are isoparaffins. Preferably at least 85 mass. % saturated paraffin hydrocarbons are non-cyclic hydrocarbons. Preferably, the naphthenic compounds (paraffinic cyclic hydrocarbons) are present in an amount of not more than 15 mass. %, more preferably less than 10 mass. %

Preferably, the especially heavy Fischer-Tropsch base oil contains hydrocarbon molecules having successive numbers of carbon atoms, so that the oil contains a continuous series of successive isoparaffins, i.e. isoparaffins having n, n + 1, n + 2, n + 3 and n + 4 carbon atoms. This series is a consequence of the synthesis of hydrocarbons in the Fischer-Tropsch process, from which a particularly heavy base oil is obtained, with subsequent isomerization of paraffin feed. Usually a particularly heavy FT base oil is a liquid under the applicable temperature and pressure conditions and usually, although not always, under standard ambient temperature and pressure conditions.

The inventors have found that the degree of paraffin cloudiness in especially heavy FT base oils tends to increase with increasing viscosity, boiling point, increasing the proportion of C ₃₀ + molecules, increasing cloud point, pour point, relative decrease in the degree of isomerization; paraffin cloudiness is more pronounced for oils obtained from residual fractions and from especially heavy paraffin hydrocarbon feedstocks than for distillate oils, and catalytic dewaxing is less effective than solvent dewaxing. Turbidity, especially in the context of dewaxing, may also be associated with these factors. Particularly heavy FT base oils in which paraffin cloudiness is a pronounced and / or sustained effect are particularly advantageous from the present invention, and are therefore preferred as effective but economical components used in the present invention.

Typically, the kinematic viscosity at 100 ° C. according to ASTM D445 (KB 100) for a particularly heavy FT base oil may be at least 15 mm ² / s. Preferably, the value of KB 100 may be at least 17 mm ² / s, more preferably at least 18 mm ² / s, even more preferably at least 19 mm ² / s, and even more preferably at least 22 mm ² / s, and most preferably at least 24 mm ² / s. In some embodiments, KB 100 may have a value of at most 100 mm ² / s, or even at most 80 mm ² / s, or at most 50 mm ² / s, or even at most 35 mm ² / s.

The kinematic viscosity at 40 ° C. according to ASTM D445 (KB 40) of the alkylated aromatic mixed feed may optionally be in the range of 20 mm ² / s to 300 mm ² / s, preferably in the range of 100 mm ² / s to 250 mm ² / from.

The viscosity index of a particularly heavy FT base oil is preferably greater than 140 and preferably lower than 170.

A particularly heavy Fischer-Tropsch base oil may have a lower boiling range (T5 or 5% distillation) of at least 420 ° C. More preferably, the lower boiling range (T5 or 5% distillation) may be at least 450 ° C, even more preferably at least 470 ° C. The upper boiling range (T80 or 80% distillation) of a particularly heavy FT base oil may be at least 600 ° C. More preferably, the upper boiling range (T80) may be at least 620 ° C., even more preferably at least 640 ° C. The lower and upper boiling temperature ranges indicated in the invention are nominal and refer to boiling temperatures T5 and T80 obtained by gas chromatographic distillation simulation (GCD) according to ASTM D-7169.

The distribution of any boiling ranges of the samples is measured in the invention according to ASTM D-7169. Since hydrocarbons produced in the Fischer-Tropsch synthesis contain a mixture of components with different molecular weights that have a wide boiling range, this description refers to the selection points for boiling ranges. For example, the selection point of 10 mass. % refers to a temperature at which 10 mass. % of the hydrocarbons present in said fraction will evaporate at atmospheric pressure and can thus be recovered. Similarly, the selection point of 90 mass. %) refers to the temperature at which 90 mass. % of the hydrocarbons present will evaporate at atmospheric pressure. Unless otherwise indicated, reference to the distribution of the boiling range means a range of boiling points with an extraction between 10 mass. % and 90 mass. % fraction.

Particularly heavy Fischer-Tropsch base oil may preferably contain at least 95 mass. % hydrocarbon molecules With ₃₀ +. More preferably, a particularly heavy FT base oil may contain at least 75 mass. % hydrocarbon molecules With ₃₅ +.

The term "cloud point" refers to the temperature at which a cloud point develops in a sample, which is determined according to ASTM D-5773. A particularly heavy FT base oil may have a cloud point in the range of + 60 ° C to + 5 ° C. Preferably, the especially heavy FT base oil has a cloud point in the range of + 50 ° C to + 10 ° C, more preferably in the range of + 45 ° C to + 15 ° C, more preferably in the range of + 40 ° C to +20 ° C and most preferably in the range from + 31 ° C to + 20 ° C.

The term "pour point" refers to the temperature at which the flow of a sample begins under carefully controlled conditions. The term “pour point” as defined herein is defined according to ASTM D-97-93. A particularly heavy Fischer-Tropsch base oil may have a pour point of -9 ° C or lower, preferably -12 ° C, or -15 ° C, or -21 ° C, or -24 ° C, or -27 ° C, or even -30 ° C, or -36 ° C, or -39 ° C, or -45 ° C, or lower. Thus, it can be a base oil of the type that undergoes relatively stiff (i.e. high temperature catalytic) dewaxing, such that it can provide a pour point of -30 ° C or lower, for example from -30 to -45 ° C. Such base oils may still contain residual paraffins, leading to turbidity and, therefore, the invention is especially useful for them. Alternatively, a particularly heavy FT base oil may undergo a relatively mild dewaxing that provides a pour point higher than -30 ° C, for example at least -15 ° C, such as in the range of -12 ° C to 0 ° C.

In addition, the especially heavy Fischer-Tropsch base oil can be characterized by its content of various carbon particles. More specifically, a particularly heavy FT base oil can be characterized by the content (in%) of epsilon-methylene carbon atoms, i.e. the percentage of repeating methylene carbon atoms that are four or more carbon atoms away from the nearest end group, as well as from the nearest branch ( hereinafter referred to as CH ₂ > 4), compared with the percentage of isopropyl carbon atoms. In the following text, the ratio of the percentage of epsilon-methylene carbon atoms to the percentage of isopropyl carbon atoms (i.e., carbon atoms in isopropyl branches), which is measured for the entire base oil, is called the ratio of epsilon: isopropyl atoms. It is established that the isomerized residual FT base oils, which are disclosed in US-A-7053254, differ from the Fischer-Tropsch derived paraffin base oil components obtained with greater dewaxing rigidity in that the latter have an epsilon: isopropyl atom ratio of 8 2 or lower. Particularly heavy FT base oils of these two types are used in the present invention. Especially heavy base oils after moderate dewaxing, having an isopropyl ratio of 8.2, can often include more pronounced paraffin haze. However, it has been found that after hard dewaxing in especially heavy base oils having an epsilon: isopropyl atom ratio of 8.2 or lower, stable turbidity can also be observed, and therefore, the beneficial effect of the present invention is unexpectedly observed.

The branching in the especially heavy Fischer-Tropsch base oil can also be expressed as the average degree of branching. The indicated average degree of branching for a particularly heavy FT base oil in some embodiments may range from about 6.5 to 10 alkyl branches per 100 carbon atoms, as described in US Pat. No. 7,053,254. In other embodiments, the average degree of branching in the molecules may be more than 10 alkyl branches per 100 carbon atoms, as determined in accordance with the method disclosed in US Pat. No. 7,053,254.

The branching characteristics as well as the carbon composition of the mixing component of the Fischer-Tropsch derived base oil can be conveniently determined by analyzing the oil sample using C-NMR, vapor pressure osmometry (VPO) and field ionization mass spectrometry (FIMS) as described in US Pat. No. 8,152,869.

Typically, a particularly heavy Fischer-Tropsch synthesis base oil may have a viscosity index (ASTM D-2270) between 120 and 180. Preferably, such an oil does not contain or has a very low content of sulfur and nitrogen compounds. This is typical of a product produced in a Fischer-Tropsch synthesis process that uses synthesis gas that is substantially free of heteroatomic impurities. Preferably, the especially heavy FT base oil includes sulfur, nitrogen and metals in the form of hydrocarbon compounds containing these impurities in an amount of less than 50 ppm. (ppm) by weight, more preferably less than 20 ppm. by weight, even more preferably less than 10 ppm by weight. Most preferably, the level of sulfur and nitrogen in the oil is usually below the detection limits, which are currently 5 ppm. by weight for sulfur and 1 ppm by weight for nitrogen, when used to determine nitrogen, for example, the X-ray method or the 'Antek' device.

The particularly heavy Fischer-Tropsch base oil is preferably the residual FT base oil, that is, the oil that is obtained from the residual or high vacuum heavy hydrocarbon fraction produced during the Fischer-Tropsch synthesis process.

More preferably, this fraction is a distillation residue that contains the highest molecular weight compounds that are still present in the product after the hydroisomerization step. Preferably the boiling point, with the extraction of 10 mass. % of said fraction is above 370 ° C, more preferably above 400 ° C and most preferably above 480 ° C for some embodiments of the present invention.

The density of the component of the especially heavy FT base oil, measured by the standard test method IP 365/97, is preferably from about 700 to 1100 kg / m ³ , preferably from about 834 to 841 kg / m ³ .

In the broadest sense, the present invention includes the use of a paraffinic component of a heavy base oil, which has one or more of the above properties, regardless of whether this component is obtained in the Fischer-Tropsch synthesis. This component of a particularly heavy FT base oil may contain a mixture of two or more fractions of a particularly heavy FT base oil.

In order to obtain a particularly heavy Fischer-Tropsch base oil for use in the present invention, the residual fractions or heavy product produced in the Fischer-Tropsch synthesis are preferably subjected to an isomerization process. In this case, n-paraffins are converted to isoparaffins, thus increasing the degree of branching of hydrocarbon molecules and improving the cold flow characteristics. Depending on the catalysts used and the isomerization conditions, in the process it is possible to obtain hydrocarbon molecules with a long chain having end groups with a high degree of branching. For such hydrocarbons, there is a tendency toward relatively good cold flow characteristics. The isomerized heavy product can subsequently be converted in subsequent processes, for example hydrocracking, hydrotreating and / or final hydrotreating. Preferably, the product is treated in the dewaxing step, either with a solvent, or more preferably with catalytic dewaxing, as described below, which further reduces the pour point of the product. However, even after dewaxing, in residual especially heavy FT base oil, residual paraffin cloudiness can still be observed due to very high molecular weight paraffins that cannot be completely removed during the dewaxing process.

In general, the particularly heavy Fischer-Tropsch base oil used in the present invention can be prepared using any suitable Fischer-Tropsch synthesis method. However, it is preferable that the component of the especially heavy FT (b) base oil is a heavy residual fraction obtained from a Fischer-Tropsch wax or paraffinic raffinate feedstock as follows:

a) hydrocracking / hydroisomerization of raw materials produced in the Fischer-Tropsch synthesis, with at least 20 mass. % compounds of raw materials produced in the Fischer-Tropsch synthesis have at least 30 carbon atoms,

b) the separation of the product of stage (a) into one or more distillate fractions and a residual heavy fraction, which preferably contains at least 10 mass. % compounds boiling above 540 ° C;

(c) catalytic conversion of the residual fraction in the step of lowering the pour point; and

(d) recovering from the converted stream in step (c), preferably in the form of a residual heavy fraction, of a Fischer-Tropsch heavy base oil component.

In addition to isomerization and fractionation, fractions of the product produced in the Fischer-Tropsch synthesis can undergo various other operations, such as hydrocracking, hydrotreating and / or final hydrotreating.

The feed from step (a) is a Fischer-Tropsch derived product. The boiling point of the Fischer-Tropsch synthesis product may reach 400 ° C. Preferably, any compounds having 4 or less carbon atoms and any compounds having a boiling point in this range are isolated from the Fischer-Tropsch synthesis product before using this synthesis product at the indicated hydroisomerization stage.

An example of a suitable Fischer-Tropsch synthesis process is described in WO-A-99/34917 and AU-A-698391. In these processes, the product of the Fischer-Tropsch synthesis is formed, as described above. The Fischer-Tropsch synthesis product can be obtained in well-known processes, for example in the so-called Sasol process, Shell distillate synthesis process, or Exxon Mobil AGC-21 process. These and other processes, for example, are described in more detail in documents EP-A-0776959, EP-A-0668342, US-A-4943672, US-A-5059299, WO-A-99/34917 and WO-A-99 / 20720. Typically, the Fischer-Tropsch synthesis process will include a Fischer-Tropsch synthesis and a hydroisomerization step, as described in these documents. Fischer-Tropsch synthesis can be carried out using synthesis gas obtained from any kind of hydrocarbon material, such as coal, natural gas, or biological material, such as wood or hay.

The Fischer-Tropsch synthesis product directly obtained from the Fischer-Tropsch synthesis process contains a paraffin fraction, which is usually solid at room temperature.

The feed for the hydroisomerization step (a) is preferably the Fischer-Tropsch synthesis product, which has at least 30 mass. %, preferably at least 50 mass. %, and more preferably at least 55 mass. % of compounds containing at least 30 carbon atoms. Moreover, in this feed, the weight ratio of compounds having at least 60 carbon atoms to compounds having at least 30 but less than 60 carbon atoms is preferably at least 0.2, more preferably at least 0 , 4, and most preferably at least 0.55. If the raw material has a boiling point with the extraction of 10 mass. % above 500 ° C, the preferred wax content will be higher than 50 mass. % Preferably, the Fischer-Tropsch synthesis product contains a C20 + fraction having an alpha-ASF (Anderson-Schulz-Flory chain growth factor) of at least 0.925, preferably at least 0.935, more preferably at least 0.945, even more preferably at least 0.955.

Preferably, step (a) of the hydrocracking / hydroisomerization process is carried out in the presence of hydrogen and a catalyst, wherein the catalyst may be selected from those known to one skilled in the art as suitable catalysts for this process. Hydroisomerization catalysts typically include acid functionality and hydrogenation-dehydrogenation functionality. Refractory metal oxide supports have a preferred acid functionality. Suitable carrier materials include silica, alumina, aluminosilicate, zirconia, titanium dioxide, and mixtures thereof. Preferred carrier materials for incorporation into the catalyst are silica, alumina, and aluminosilicate. A particularly preferred catalyst comprises platinum supported on an aluminosilicate carrier. Preferably, the catalyst does not contain halogen compounds, such as, for example, fluorine, since the use of such catalysts may require special operating conditions and environmental problems. Examples of suitable hydrocracking / hydroisomerization processes and catalysts are described in WO-A-00/14179, EP-A-0532118, EP-A-0666894 and EP-A-0776959.

Preferably, Group VIII metals, for example cobalt, nickel, palladium and platinum, more preferably platinum, have hydrogenation-dehydrogenation functionality. In the case of platinum and palladium, the catalyst may contain a hydrogenation-dehydrogenation active component in an amount of from 0.005 to 5 parts by weight, preferably from 0.02 to 2 parts by weight, per 100 parts by weight of carrier material. In the case of nickel, elevated contents are usually used, and optionally nickel is used in combination with copper. A particularly preferred catalyst for use in the hydrogenation conversion step contains platinum in an amount of from 0.05 to 2 parts by weight, more preferably from 0.1 to 1 parts by weight, per 100 parts by weight of carrier material. In addition, the catalyst may contain a binder material to increase the strength of the catalyst. Binder material may be non-acidic. An example is clay and other binders known to those skilled in the art.

During hydroisomerization, the feed is contacted with hydrogen in the presence of a catalyst at elevated temperature and pressure. Typically, the temperature will be in the range from 175 to 380 ° C., preferably higher than 250 ° C. and more preferably from 300 to 370 ° C. Typical pressure will be in the range from 10 to 250 bar (1 to 25 MPa) and preferably from 20 to 80 bar (2.0 to 8.0 MPa). Hydrogen gas can flow at a space velocity of from 100 to 10,000 nl / l per hour, preferably from 500 to 5,000 nl / l per hour. The hydrocarbon feed can be supplied at a mass flow rate of from 0.1 to 5 kg / l per hour, preferably more than 0.5 kg / l per hour and more preferably less than 2 kg / l per hour. The ratio of hydrogen to hydrocarbon feed can vary from 100 to 5000 nl / kg and preferably from 250 to 2500 nl / kg.

The degree of conversion during hydroisomerization, defined as the percentage of raw materials (by weight) boiling above 370 ° C, which is converted in one pass into a fraction boiling below 370 ° C, is preferably at least 20 mass. %, preferably at least 25 mass. %, but preferably not more than 80 mass. %, more preferably not more than 70 mass. % The definition of feedstock used above is the total hydrocarbon feed to the hydroisomerization step, and thus also any optional stream recycle to step (a).

The product formed during the hydroisomerization process preferably contains at least 50 mass. % isoparaffins, more preferably at least 60 mass. %, even more preferably at least 70 mass. %, and the rest consists of n-paraffinic, naphthenic and aromatic compounds.

In step (b), the product of step (a) is separated into one or more distillate fractions and a residual heavy fraction, which preferably contains at least 10 masses. %) of compounds boiling above 540 ° C. This is conveniently done by performing one or more distillation separations of the stream leaving the hydroisomerization step in order to obtain at least one fuel fraction of the middle distillate and a residual fraction that can be used in step (c).

Preferably, the stream leaving step (a) is first subjected to atmospheric distillation. Preferably the boiling point with a selection of 10 mass. % of the residue may vary between 350 and 550 ° C. In this residual product or the residue of atmospheric distillation, preferably at least 95 mass. % boil above 370 ° C. The residue obtained by such distillation, in some preferred embodiments, can be subjected to further distillation, carried out under conditions close to vacuum, to obtain a fraction having a higher boiling point with a selection of 10 mass. %

This fraction can be used directly in step (c) or it can be subjected to additional vacuum distillation, which is preferably carried out under a pressure of between 0.1 and 10 kPa. The feed for step (c) is preferably obtained as a residual product of said vacuum distillation.

In step (c), the heavy residual fraction obtained in step (b) is treated in the catalytic step of reducing the pour point. Stage (C) can be carried out using any process of hydrogenation transformation, in which it is possible to reduce the initial content of the wax is not less than 50 mass. % Preferably, the wax content of the intermediate is less than 35 mass. % and more preferably between 5 and 35 mass. %, and even more preferably between 10 and 35 mass. % Preferably, the product obtained in step (c) has a freezing point below 80 ° C. Preferably more than 50 mass. % and more preferably more than 70 mass. % of the intermediate product is boiled higher than the extraction temperature of 10 mass. % wax used as raw material in stage (a).

The wax content can be measured according to the following procedure: 1 mass part of the analyzed oil fraction is diluted with 4 parts (50/50 by volume) of a mixture of methyl ethyl ketone and toluene, and the entire mixture is successively cooled in the refrigerator to -20 ° C. Then this mixture is filtered at -20 ° C. The wax is thoroughly washed with a cold solvent, taken from the filter, dried and weighed. Where reference is made to the oil content, the value in mass. % means the part obtained by subtraction: 100 mass. % minus the wax content in mass. %

For step (c), a possible process is hydroisomerization, which is described above for step (a). It has been found that the wax content can be reduced to the desired level using these catalysts. By varying the severity of the conditions of the process described above, one skilled in the art can easily determine the operating conditions necessary to achieve the desired degree of wax conversion. However, a temperature between 300 and 330 ° C. and a mass feed rate between 0.1 and 5, more preferably between 0.1 and 3 kg of oil per 1 liter of catalyst per hour (kg / l per hour) are particularly preferred for optimization oil outlet. A more preferred class of catalysts that can be used in step (c) is the class of dewaxing catalysts. The process conditions used using these catalysts should support the wax content of the oil. In contrast, in typical catalytic dewaxing processes, the goal is to reduce the wax content to almost zero. Using a dewaxing catalyst that contains a molecular sieve, it is possible to obtain an increased content of "heavy" molecules in dewaxed oil. Then you can get a more viscous base oil.

The dewaxing catalyst that can be used in step (c) suitably contains a molecular sieve, optionally in combination with a metal having hydrogenation activity, such as a Group VIII metal. Molecular sieves, and more preferably molecular sieves having a pore diameter between 0.35 and 0.8 nm, have shown good catalytic activity to reduce the wax content of paraffin feed. Suitable zeolites are mordenite, beta zeolite, ZSM-5, ZSM-12, ZSM-22, ZSM-23, SSZ-32, ZSM-35, ZSM-48, EU-2 and combinations of these zeolites, of which the most preferred are ZSM-12, ZSM-48 and EU-2.

In the present invention, reference is made to ZSM-48 and EU-2 in order to show that all zeolites that belong to the ZSM-48 disordered structure family, which is also called the * MRE family, are described in the Catalog of Disorder catalog. in Zeolite Frameworks ”, published in 2000 on behalf of the Structural Commission of the International Zeolite Association. Even though it might be considered that EU-2 is different from ZSM-48, both ZSM-48 and EU-2 can be used in the present invention. Zeolites ZBM-30 and EU-11 are very similar to ZSM-48 and are also considered as representatives of zeolites whose structure belongs to the ZSM-48 family. In the present invention, any reference to ZSM-48 zeolite is also a reference to zeolites ZBM-30 and EU-11. In addition to zeolites ZSM-48 and / or EU-2, additional zeolites may be present in the catalyst composition, especially if it is desirable to modify the catalytic properties of zeolites. It has been established that the presence of zeolite ZSM-12, which is defined in the Database of Zeolite Structures, published in 2007/2008 on behalf of the Structural Commission of the International Zeolite Association, may be beneficial.

Another preferred group of molecular sieves are aluminosilicate phosphate (SAPO) materials, of which SAPO-11 is most preferred, as described, for example, in US-A-4859311. Zeolite ZSM-5 can optionally be used in the form of HZSM-5 in the absence of any Group VIII metal. Other molecular sieves are preferably used in combination with added Group VIII metal. Suitable Group VIII metals are nickel, cobalt, platinum and palladium. Examples of possible combinations are Pt / ZSM-35, Ni / ZSM-5, Pt / ZSM-23, Pd / ZSM-23, Pt / ZSM-48 nPt / SAPO-11, or multilayer configurations of Pt / zeolite-beta and Pt / ZSM-23, Pt / zeolite beta and Pt / ZSM-48, or Pt / zeolite beta and Pt / ZSM-22. Further details and examples of suitable molecular sieves and dewaxing conditions are described, for example, in documents WO-A-97/18278, US-A-4343692, US-A-5053373, US-A-5252527, US-A-2004/0065581, US-A-4574043 and EP-A-1029029. Another preferred class of molecular sieves includes zeolites having relatively low isomerization selectivity and high wax conversion selectivity, like ZSM-5 and ferrierite (ZSM-35).

In addition, the dewaxing catalyst preferably contains a binder material. This binder material may be a substance having a synthetic or natural (inorganic) origin, for example, clay, silica and / or metal oxide. Clays of the montmorillonite and kaolin family are examples of naturally occurring clays. Preferably, the binder material is a porous binder material, for example, refractory oxide, examples of which include alumina, aluminosilicate, silica-magnesium oxide, silica-zirconia, silica-thorium dioxide, silica-beryllium dioxide and silica-titanium dioxide as well as ternary compositions, for example, aluminosilicate-thorium dioxide, aluminosilicate-zirconia, aluminosilicate-magnesium oxide and silica-magnesium oxide-zirconia. More preferably, a low-acid refractory oxide binder material that is substantially free of alumina is used. Examples of these binders are silicon dioxide, zirconia, titanium dioxide, germanium dioxide, boron oxide and mixtures of two or more oxides, examples of which are indicated above. The first preferred binder is silica. A second preferred binder is titanium dioxide.

A preferred class of dewaxing catalysts includes intermediate zeolite crystallites as described above and a refractory, low acidity oxide binder material that is substantially free of alumina as described above; moreover, the surface of the crystallites of aluminosilicate zeolite is modified by dealuminating treatment, which is subjected to the surface of these crystallites. Preferably dealumination treatment includes contacting the extrudate of the binder material and the zeolite with an aqueous solution of fluorosilicate salt, as described, for example, in documents US-A-5157191 or WO-A-00/29511. Examples of suitable dewaxing catalysts described above are silica bonded to dealuminated Pt / ZSM-5 or silica bonded to dealuminated Pt / ZSM-35, for example, as described in WO-A-00/29511 and EP- B-0832171.

The conditions in step (c) using a dewaxing catalyst typically include operating temperatures in the range from 200 to 500 ° C., preferably from 250 to 400 ° C. Preferably, the temperature is between 300 and 330 ° C. The hydrogen pressure may vary from 10 to 200 bar, preferably from 40 to 70 bar. The mass feed rate (WHSV) can vary from 0.1 to 10 kg of oil per 1 liter of catalyst per hour (kg / l per hour), preferably from 0.1 to 5 kg / l per hour, more preferably from 0.1 to 3 kg / l per hour. The hydrogen / oil ratio can vary from 100 to 2000 liters of hydrogen per liter of oil.

In step (d), the product of step (c) is usually sent to a vacuum column, where various distillate fractions of the base oil are collected. These distillate fractions of the base oil can be used to prepare lubricant base oil mixtures, or these fractions can be cracked to form lower boiling products such as diesel or naphtha. The residual material taken from the vacuum column contains a mixture of high boiling hydrocarbons and can be used to produce the especially heavy FT base oil used in the present invention.

In addition, the product obtained in step (c) can also be further processed, for example, in the process of cleaning with bleaching clay or by contacting with active carbon, as described, for example, in US-A-4795546 and EP-A-0712922, in order to remove unwanted components. Other suitable methods for the production of heavy and especially heavy base oils based on Fischer-Tropsch synthesis are described in documents WO-A-2004/033607, US-A-7053254, EP-A-1366134, EP-A-1382639, EP-A-1516038 , EP-A-1534801, WO-A-2004/003113 and WO-A-2005/063941.

A particularly heavy Fischer-Tropsch base oil is defined and described in the invention as an added component. Optionally, this component is the only source of a particularly heavy FT base oil in the lubricating composition, but this is not significant. Thus, another particularly heavy FT base oil may be present in the lubricating composition, and the amounts of the especially heavy FT base oil indicated in the invention must be interpreted accordingly, unless the context requires otherwise.

A particularly heavy FT base oil may consist of or be equivalent to any particularly heavy FT base oils described or defined in the invention, or any combination thereof.

A particularly heavy Fischer-Tropsch base oil may be turbid in the sense that it does not meet the clear and bright standard (ASTM D4176-04) under standard conditions and / or has a measurable turbidity of at least 0.5 NTU units (nephelometric turbidity unit), preferably at least 1 NTU, more preferably at least 2 NTU, even more preferably at least 3 NTU and most preferably at least 4 NTU units. Turbidity can be measured at 25 ° C according to the procedure described in document US 2011/0083995. A particularly heavy FT base oil may be opaque.

The amount of especially heavy FT base oil can be adjusted to achieve the desired degree of reduction in paraffin cloudiness and viscometric characteristics. The effective amounts of the especially heavy FT base oil will to some extent depend on the nature of the especially heavy FT base oil, as well as on the nature of the alkylated aromatic mixed feed with which the oil is combined.

In embodiments of the invention, the amount of a particularly heavy FT base oil is in the range of 5 to 50 mass. %, preferably from 10 to 40 mass. %, more preferably from 15 to 35 mass. %, especially from 20 to 25 mass. % based on the total weight of the especially heavy FT base oil and alkylated aromatic mixed feed.

A second essential component of the invention is an alkyl aromatic mixed feed. Alkylated aromatic mixed raw materials may contain or consist of one or more alkylated aromatic compounds (alkylated aromatic) in accordance with the achievement of the desired characteristics of the lubricating composition.

Alkylated aromatic compounds have an aromatic basic group and at least one alkyl chain.

The aromatic basic group may be a substituted or unsubstituted mono- or polycyclic ring structure. In addition, an aromatic basic group that contains one or more heteroatoms may be suitable. In the context of the invention, preferred aromatic basic groups are benzene and naphthalene, with naphthalene being particularly preferred.

Preferably, each one or more alkyl chains in the alkyl aromatics, individually, may be a C ₁ -C ₃₀ group, for example a linear C ₁ -C ₂₀ alkyl group; or a C ₃ -C ₃₀₀ , for example a C ₃ -C ₁₀₀ , or a branched C ₃ -C ₃₀ alkyl group. Elongated alkyl chains can provide reduced volatility and improve viscometric performance. In some embodiments, the at least one linear or branched alkyl group in the alkyl aromatics may preferably contain at least ten carbon atoms, more preferably at least 15 carbon atoms, for example being C ₁₀ -C ₃₀ , or C ₁₀ -C ₂₀ or C ₁₅ -C ₃₀ , or C ₁₀ -C ₁₅ linear alkyl group, or C ₁₀ -C ₃₀₀ , or C ₁₀ -C ₁₀₀ , or C ₁₀ -C ₃₀ , or C ₁₅ -C ₃₀₀ , or C ₁₅ - C ₁₀₀ , or C ₁₅ -C ₃₀ branched alkyl group.

The number of alkyl chains in one aromatic main group may be different. One or more alkyl chains, for example one, two, three, four, five or six alkyl chains, can be directly connected to the aromatic system of the aromatic main group. The alkyl chain may be associated with the aromatic system at each available position in the aromatic main group.

To achieve the desired volatility characteristics, the average number of carbon atoms in the alkylated aromatics may be at least 11, preferably at least 15, more preferably at least 25, or even at least 40. The alkylated aromatics may have a number average molecular weight of at least at least about 150, preferably at least about 180, and more preferably at least about 300, or even at least about 480.

The production of alkyl aromatics is well known in the art. Although any preparation method is suitable in the context of the invention, a suitable alkyl aromatics can conveniently be obtained in the process of alkylation of an aromatic compound with an alkylating agent. Olefins are particularly common alkylating agents in the art. Typically, the alkylation process is carried out in the presence of acidic catalysts, especially Friedel-Crafts catalysts such as AlCl ₃ , BF ₃ , FeCl ₃ , acid zeolites, amorphous aluminosilicates, acidic clays or acidic metal oxides. Typically, alkylated aromatics obtained by alkylation include a mixture of compounds and isomers.

As will be apparent to one skilled in the art, it is also possible to obtain a short chain alkylated aromatic compound from oil refining processes or other petrochemical processes. Said raw materials containing alkyl aromatics can conveniently be obtained by aromatizing a suitable stream available from the FT process. The alkylated aromatics thus obtained can be used directly in the invention, or as an alkylation feed, depending on the desired characteristics.

In addition, the hydrogenated or partially hydrogenated alkylated aromatic analogs described in the invention may optionally be used in (or as) an alkylated aromatic mixed feed.

Alkylated naphthalenes are particularly preferred alkylated aromatic hydrocarbons for use in (or as) an alkylated aromatic mixed feed. Alkylated naphthalenes used in the context of the invention may have the following general formula (I):

in which the sum of (A + B) is from 1 to 8, preferably from 1 to 6, more preferably from 1 to 5, and R represents a C ₁ -C ₃₀ , preferably a C ₁ -C ₂₀ linear alkyl group, C ₃ - C ₃₀₀ , preferably C ₃ -C ₁₀₀ , more preferably C ₃ -C ₃₀ branched alkyl groups or mixtures of these groups with a total number of carbon atoms in R _A and R _B , preferably equal to at least 4.

Examples of typical alkylnaphthalenes are mono-, di-, tri-, tetra- or penta-C ₃ -alkylnaphthalene, C ₄ -alkylnaphthalene, C ₅ -alkylnaphthalene, C ₆ -alkylnaphthalene, C ₈ -alkylnaphthalene, C ₁₀ -alkylnaphthalene, C ₁₂ -alkylnaphthalene, C ₁₄ -alkylnaphthalene, C ₁₆ -alkylnaphthalene, C ₁₈ -alkylnaphthalene and others, mixed C ₁₀ -C ₁₄ -alkylnaphthalenes, mixed C ₆ -C ₈ -alkylnaphthalenes, or mono-, di-, tri-, tetra or penta-C ₃ , C ₄ , C ₅ , C ₆ , C ₈ , C ₁₀ , C ₁₂ , C ₁₄ , C ₁₆ , C _18, or mixtures thereof, alkyl monomethyl, dimethyl, ethyl, diethyl, or methylethylnaphthalene, or mixtures. In addition, the alkyl group may be a branched alkyl group having from C ₁₀ to C ₃₀₀ , for example, C ₂₄ -C ₅₆ -branched alkylnaphthalenes, C ₂₄ -C ₅₆ -branched alkyl-mono-, di-, tri-, tetra- or penta-C ₁ -C ₄ naphthalenes. These branched alkyl groups of substituted naphthalenes or branched alkyl groups of substituted mono-, di-, tri-, tetra- or penta-C ₁ -C ₄ -naphthalenes can also be used as mixtures with the previously mentioned materials. When the branched alkyl group is very large (i.e., from 8 to 300 carbon atoms), usually only one or two of these alkyl groups are attached to the naphthalene main group. Alkyl groups on the naphthalene ring may be mixtures of any of the above alkyl groups.

Typically, alkyl naphthalenes are prepared by short chain alkylation of naphthalene or alkyl naphthalene, such as methyl or dimethyl naphthalene, with olefins, alcohols or alkyl chlorides in the presence of acid catalysts, including typical Friedel-Crafts catalysts. Methods for producing alkylnaphthalenes suitable for use in the present invention are described in US Pat. Nos. 5,034,563, US 5,516,954 and US 6,436,882, as well as in the references cited in these patents, and in any other literature. Since methods for the synthesis of alkylated naphthalenes are well known in the art, these methods will not be described in detail in the invention.

Suitable alkyl naphthalenes are commercially available from ExxonMobil Chemical Company (TM) under the trade name Synesstic AN (TM).

Alkylated benzenes are the preferred alkylated aromatic hydrocarbons used in the invention. Alkylated benzenes used in the context of the invention may have the following general formula (II):

In this structure, C is from 1 to 6, preferably from 1 to 5, more preferably from 1 to 4. When the compound is monoalkylated benzene, R may be a linear C ₁₀ -C ₃₀ alkyl group or a C ₁₀ -C ₃₀₀ branched alkyl a group preferably a C ₁₀ -C ₁₀₀ branched alkyl group, more preferably a C ₁₅ -C ₅₀ branched alkyl group. When C is two or more than two, up to C-1 alkyl groups may independently be small alkyl groups from C ₁ to C ₅ , preferably C ₁ -C ₂ -alkyl groups, with at least one remaining alkyl group being linear C ₁₀ A C ₃₀ alkyl group or a C _{100 to} C ₃₀₀ branched alkyl group, preferably a C _{10 to} C ₁₀₀ branched alkyl group, more preferably a C _{15 to} C ₅₀ branched alkyl group. Branched large alkyl radicals can be obtained by oligomerization or polymerization of C ₃ -C ₂₀ internal or alpha olefins or a mixture of these olefins.

Alkylated benzene can be prepared by short chain alkylation of benzene or alkylbenzene, such as methyl or dimethylbenzene, olefins, alcohols or alkyl chlorides in the presence of acidic catalysts, including typical Friedel-Crafts catalysts. Preferred alkylated benzene fluids may be prepared according to US Pat. No. 6,071,864 or US Pat. No. 6,491,809 or EP 0168534.

Alkylated aromatic mixed raw materials are defined and described in the invention as an added component. These raw materials may optionally be the only source of alkylated aromatics in the lubricating composition, but are not required. Thus, other alkylated aromatic compounds may be present in the lubricating composition, the amounts of alkylated aromatic compounds indicated in the invention to be interpreted accordingly, unless the context otherwise indicates.

Alkylated aromatic mixed raw materials may consist of (or be analogous to) any alkylated aromatic compound as defined and described in the invention, or any combination thereof, for example, alkyl naphthalenes and / or alkyl benzenes.

The kinematic viscosity at 100 ° C. according to ASTM D445 (KB 100) of the alkylated aromatic mixed feed can be in the range of 1 mm ² / s to 50 mm ² / s, preferably in the range of 2 mm ² / s to 30 mm ² / s more preferably in the range from 3 mm ² / s to 20 mm ² / s, most preferably in the range from 4 mm ² / s to 15 mm ² / s, for example from 4 to 7 mm ² / s or from 11 to 15 mm ² / s.

The kinematic viscosity at 40 ° C. according to ASTM D445 (KB 40) of the alkylated aromatic mixed feed can be in the range of 20 mm ² / s to 150 mm ² / s, preferably in the range of 25 mm ² / s to 120 mm ² / s.

Preferably, the alkylated aromatic mixed feed may have a pour point (ASTM D97) of 0 ° C. or lower, preferably −20 ° C., more preferably −30 ° C. or lower; and / or a viscosity index (ASTM D 2270) in the range of from about 0 to 200, preferably from about 60 to 200, more preferably from about 70 to 160, for example, from about 75 to 110; and / or Noack volatility (ASTM D5800) less than 15 mass. %, preferably 7 mass. %, more preferably 5 wt. %

The amount of alkylated aromatic mixed feed can be adjusted to achieve the desired reduction in paraffin haze. To some extent, the effective amount of the alkylated aromatic mixed feed will depend on the nature of the mixed feed and also on the nature of the residual FT oil with which it is combined.

In some embodiments, the amount of alkylated aromatic mixed feed is in the range from 50 to 95 mass. %, preferably 60 to 90 mass. %, more preferably 65 to 85 mass. %, especially 75 to 80 mass. %, based on the entire mass of especially heavy base oil FT and alkylated aromatic mixed raw materials.

The lubricating composition has a less cloudy appearance than the especially heavy FT base oil used to formulate the composition. Advantageously, the lubricating composition may conform to the transparent and light standard (ASTM D4176-04). Preferably, the composition may have a turbidity of at most 2 NTU units, preferably at most 1 NTU, more preferably at most 0.5 NTU, even more preferably at most 0.2 NTU and ideally 0 NTU measured at 25 ° C. according to the method of US 2011/0083995. Advantageously, the lubricating composition may satisfy one or more of the above turbidity values for at least 14 days after mixing.

The kinematic viscosity of the lubricating composition at 100 ° C according to ASTM D445 (KB 100) can preferably be in the range from 1 mm ² / s to 30 mm ² / s, preferably in the range from 2 mm ² / s to 25 mm ² / s, more preferably in the range from 3 mm ² / s to 20 mm ² / s, most preferably in the range from 4 mm ² / s to 18 mm ² / s, for example from 7 to 12 mm ² / s or 14 to 17 mm ² / from.

The kinematic viscosity at 40 ° C. according to ASTM D445 (KB 40) of the lubricating composition can preferably be in the range from 30 mm ² / s to 150 mm ² / s, preferably in the range from 35 mm ² / s to 140 mm ² / s.

The lubricating composition may have a viscosity index (ASTM D-2270) in the range from 95 to 180, preferably from 110 to 130.

The pour point of the lubricating composition (ASTM D-97-93) may be -10 ° C or lower, preferably -15 ° C or lower, more preferably -20 ° C or lower, even more preferably -30 ° C or lower.

The lubricating composition has unexpectedly good oxidative stability, and can preferably exhibit oxidation characteristics corresponding to a Group II base oil.

In some preferred embodiments of the invention, a lubricating composition that includes a particularly heavy FT base oil and an alkylated aromatic mixed feed may comprise:

from 5 to 25 mass. % based on the total weight of the especially heavy FT base oil and the alkylated aromatic mixed feed of the especially heavy FT base oil, which has a KB 100 of at least 15 mm ² / s; and

from 75 to 95 mass. % based on the total weight of the especially heavy FT base oil and the alkylated aromatic mixed feed of the alkylated aromatic mixed feed that contains or consists of alkyl naphthalenes and has a KB of 100 in the range of 4 mm ² / s to 15 mm ² / s.

In other preferred embodiments, a lubricating composition that includes a particularly heavy FT base oil and an alkylated aromatic mixed feed may comprise:

from 5 to 35 mass. % based on the total weight of the especially heavy FT base oil and the alkylated aromatic mixed feed of the especially heavy FT base oil having KB 100 of at least 15 mm ² / s; and

from 65 to 95 mass. % based on the total weight of the especially heavy FT base oil and the alkylated aromatic mixed feed of the alkylated aromatic mixed feed that contains or consists of alkylated naphthalenes and has a KB of 100 in the range of 11 mm ² / s to 15 mm ² / s.

Particularly heavy FT base oil and alkylated aromatic mixed feeds may fully comprise a lubricating composition, or preferably at least 95 wt. % or at least 98 wt. % or at least 99 wt. % or at least 99.5 mass. % or at least 99.99 mass. % of the total composition.

In addition, the lubricating composition according to the present invention may contain one or more additives, such as antioxidant, anti-wear additives, (preferably ashless) dispersing, washing, extreme pressure additives, friction modifiers, metal deactivators, corrosion inhibitors, demulsifiers, anti-foam additives, compatibility additives with compatibility with a sealant and additives are diluents of base oils, etc. Typically, these additives will be present in small quantities.

Since the above and other additives are known to those skilled in the art, they are not further discussed in detail. Specific examples of these additives are described, for example, in the Encyclopedia of Chemical Technology, Kirk-Othmer, 3rd edition, Volume 14, pages 477-526.

A lubricating composition may be used as a mixed lubricant feedstock, or in any suitable lubricant application. The composition may be particularly advantageous as a mixed base oil component where a relatively high KB 100 value is required, for example in internal combustion engine oils with intrinsic viscosity characteristics (SAE 40 monosort oils), where modern low-sulfur base oils such as those from Group II or Group III API, sometimes have a boundary value of KB 100, and therefore for monosortic oils there is a problem of compliance with the SAE J-300 viscometric requirements.

A lubricating composition can be obtained by simply mixing the constituent components, as is known in the art. One preferred method according to the invention includes: mixing a particularly heavy FT base oil that is not transparent and light (ASTM D4176) with a certain amount of alkylated aromatic blended material to form a lubricant composition that is transparent and bright (ASTM D4176) and / or has other properties as defined above.

The invention further encompasses the use of an alkylated aromatic mixed feed to reduce paraffin cloudiness in a particularly heavy FT base oil, or in a precursor composition that contains a particularly heavy FT base oil. This use may include providing or preparing a lubricating composition comprising a particularly heavy FT base oil and an alkylated aromatic mixed feedstock, along with information or advertising relating to a clear and bright appearance or an appearance with little or no turbidity.

Further, the present invention will be further characterized by the following non-limiting examples.

Example 1 - turbidity

The fluid properties and appearance of lubricating compositions containing a particularly heavy FT base oil (OTBM) and an alkylated aromatic base component are compared with the corresponding characteristics of the individual components according to the following ASTM standard test methods:

- Kinematic viscosity (ASTM 445). Measured at 40 ° С and 100 ° С in cSt (mm ² / s) - KB 40 and KB 100

- Viscosity Index (ASTM D2270) - IV

- "Transparent and bright" standard (ASTM D4176) at ambient conditions (20 ° C)

- Flow point (ASTM D97)

- Cloud Point (ASTM D-5773)

The base component of a high temperature pour point HBS (high TT) was prepared in much the same way as described in Example 6 of US Pat. No. 8,152,869.

The basic component of a low temperature pour point HBS (low TT) was prepared in the same way, with the only difference being the temperature at which the dewaxing catalyst was operated. The increased dewaxing temperature leads to an increase in the rigidity of the process and a decrease in the pour point.

The obtained base component of the TSS has the characteristics listed in table 1.

The distribution of the boiling range of the basic components of the HSE is analyzed according to ASTM D-7169. The distribution of the number of carbon atoms is also determined according to ASTM D-7169. The results are presented in table 2.

Alkylated aromatic base components are alkyl naphthalenes that are commercially available from ExxonMobil Chemical Company under the trademarks Synesstic ™ AN 5 and Synesstic ™ AN 12. Measurements showed that these components have the characteristics shown in Table 3, and are clear and bright appearance.

Prepared 23 mixtures of lubricating compositions from HBS and alkyl aromatic base components. The composition and measured characteristics of the mixtures are shown in tables 4-7.

As can be seen, clear and bright mixtures can be obtained using an alkylated aromatic base component.

In addition, it was shown that while the kinematic viscosity of all mixtures, at a temperature of 40 ° C, as well as at 100 ° C, decreases with an increase in the proportion of alkylated aromatic mixed raw materials with a relatively low viscosity, the viscosity index (IV) remains almost constant and comparable to the VI of the base oil of Group II API (VI> 110).

The synergistic properties of the mixture according to the invention are further demonstrated by the example of improving the pour point (TT) in comparison with the individual alkylated aromatic base component and components of the base oil OTBM. This shows that the alkylated aromatic base component can increase the solubility of cloudy paraffins in a particularly heavy FT base oil, and a particularly heavy FT base oil can lower the pour point of the alkylated aromatic base component in the mixture more than the individual components.

Example 2 - Oxidative Stability

To evaluate oxidative stability, the lubricating compositions of the invention were compared with two heavy viscous distillate base oils of API grade, Group II (Motiva Star 12, available from Motiva Enterprises LLC, and Formosa 500N, available from HS Oil & Chemical International).

As a suitable vehicle for testing the oxidative stability characteristics, an industrial turbine oil was chosen to which base oils / mixtures were added. This choice is associated with a low level of additives in the oil, however, the results are applicable to other industrial lubricants, such as hydraulic fluids or crankcase oil for diesel cars operating in difficult conditions. The following additives were used:

- Lubad 1128 is a patented additive package for industrial turbine oil, containing: (1) antioxidants, including N-phenylated naphthylamines, diphenylamines; and (2) corrosion inhibitors, including derivatives of glycol ethers, ethoxylated carboxylic acids and fatty acids;

- Synative AC AMN-2 is a dual-action additive; low silica antifoam and demulsifier (both components are required for industrial turbine oils).

The measurements were carried out in accordance with the standard oxidative test in a rotating pressure autoclave (RPVOT), formerly known as RBOT (ASTM D2272).

Four formulations were prepared, shown in table 8, which also shows the results of the RPVOT test.

It could be expected that aromatic hydrocarbons of the main group present in alkylated naphthalene fluids will lead to the oxidative sensitivity of any mixture into which fluids are introduced.

As shown in table 8, in fact, it was found that the formulation based on the mixtures obtained according to the present invention (formulations 1 and 2), which include the component of the alkylated aromatic mixed raw materials, unexpectedly exhibit oxidative stability comparable to the stability of typical API Group base oils II (formulations 3 and 4). This provides additional evidence of an unexpected and beneficial synergistic effect when mixing HBS with alkylated aromatic mixed feed.

Claims (15)

1. A lubricating composition containing a particularly heavy base oil of Fischer-Tropsch synthesis (FT) having a kinematic viscosity at 100 ° C in the range from 19 to 35 mm ² / s, and an alkylated aromatic mixed feed having a kinematic viscosity at 100 ° C ( ASTM D445) in the range of 4 mm ² / s to 15 mm ² / s, in which the alkyl aromatic mixed feed contains alkyl aromatic naphthalene and / or alkyl aromatic benzene. 2. A lubricating composition according to claim 1, wherein the especially heavy FT base oil has a lower boiling range (T5) of at least 420 ° C and an upper boiling range (T80) of at least 600 ° C. 3. A lubricating composition according to claim 1 or 2, wherein the especially heavy FT base oil contains at least 95 wt.% C30 + hydrocarbon molecules and at least 75 wt.% C35 + hydrocarbon molecules. 4. A lubricating composition according to claim 1 or 2, wherein the especially heavy FT base oil has a cloud point in the range of + 60 ° C to + 5 ° C and a pour point of -6 ° C or lower. 5. A lubricating composition according to claim 1 or 2, wherein the especially heavy FT base oil is a residual base oil. 6. The lubricating composition according to claim 5, in which a particularly heavy FT base oil is obtained from a Fischer-Tropsch synthesis product, in which there is at least 55 wt.% Compounds containing at least 30 carbon atoms, and in which the mass ratio of compounds having at least 60 carbon atoms to compounds having at least 30 but less than 60 carbon atoms is at least 0.4. 7. A lubricating composition according to claim 1, 2 or 6, in which the especially heavy FT base oil is cloudy in the sense that it does not meet the “clear and bright” standard (ASTM D4176-04) under standard conditions. 8. A lubricating composition according to claim 1, 2 or 6, which corresponds to the standard "transparent and bright" (ASTM D4176-04) under standard environmental conditions. 9. A lubricating composition according to claim 1, 2 or 6, containing: a) from 5 to 25% by weight of a particularly heavy FT base oil, based on the total weight of a particularly heavy FT base oil and an alkylated aromatic mixed feed, wherein a particularly heavy FT base oil has an KV 100 of at least 15 mm ² / s; and b) from 75 to 95% by weight of alkylated aromatic mixed feed, based on the total weight of the especially heavy FT base oil and alkylated aromatic mixed feed, wherein the alkylated aromatic mixed feed contains or consists of alkylated naphthalenes and has a KV of 100 in the range of 4 mm ² / s to 15 mm ² / s. 10. The use of a lubricating composition according to any one of the preceding paragraphs for the lubrication of an engine, compressor, hydraulic pump, industrial turbine, gearbox or power transmission system. 11. A method for producing a lubricating composition comprising mixing an especially heavy FT base oil that does not meet the Clear and Light standard (ASTM D4176) with an alkylated aromatic mixed feed to obtain a transparent and light lubricating composition. 12. The use of alkylated aromatic mixed feeds to reduce paraffin cloudiness in a particularly heavy FT base oil or in a precursor composition containing a particularly heavy FT base oil.