NL1027242C2 - Basic lubricating oils with an optimized branching. - Google Patents

Description

Basic lubricating oils with an optimized branching

FIELD OF THE INVENTION This invention relates to base lubricating oils comprising paraffinic components that have an optimized branching. The base lubricating oils comprising paraffinic components with an optimized branching have a low degree of branching, with the branching concentrated toward the center of the base lubricating oil molecules. The basic lubricating oils comprising paraffinic components with an optimized branching have low pour points and extremely high viscosity indices. The invention further relates to processes for producing the basic lubricating oils comprising paraffinic components with an optimized branching. The basic lubricating oils are useful in commercially available ready lubricants.

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BACKGROUND OF THE INVENTION

High quality lubricants should be paraffinic in nature, and in general, as paraffins have a high viscosity index. However, normal paraffins, in particular, are waxy in nature and contribute to a high pour point in the oil. Accordingly, waxy paraffinic feeds can be converted to base lubricating oils by hydroisomerization dewaxing, thereby forming branches on the paraffinic molecules. Hydroisomerization dewaxing usually gives a base lubricating oil with a relatively high degree of branching. While the flow point is generally lowered by forming branches on waxy paraffinic molecules, the viscosity index (VI) is also lowered here. A high degree of branching is required with a complete hydroisomerization process to achieve the intended flow cloud points. Accordingly, the products obtained from hydroisomerization processes usually have less than optimum viscosity indices due to the relatively high degree of branching. Basic lubricating oil products produced by a hydroisomerization process may have 2 branching characteristics that are similar to those described in U.S. Patent Nos. 6,096,940, 6,090,989, and 6,059,955.

Low pour points are desired with basic lubricating oils. A low pour point indicates that a basic lubricating oil flows and lubricates at low temperatures. The pour point is a measure of the temperature at which the sample begins to flow under carefully controlled conditions. The pour point can be determined as described in ASTM D 5950. Many commercially available basic lubricating oils have specifications for the pour point. If base lubricating oils have low pour points, they probably also have other good properties at low temperature, such as a low cloud point, a low blocking point of a cold filter and low temperature gas mixing viscosity.

Base lubricating oils with flow cloud point spreads of less than about 30 ° C are also desirable. Higher flow cloud point spreads require processing of the base lubricating oil into very low pour points to meet the cloud point specifications.

It is further desired to have base lubricating oils with high viscosity indices. The viscosity index (VI) is an empirical, unitless number that reflects the effect of the temperature change on the kinematic viscosity of the oil. The viscosity of liquids changes with temperature and liquids become less viscous on heating; the higher the VI of an oil, the lower its tendency to change viscosity with temperature. Lubricants with a high VI are needed where a relatively constant viscosity is required at widely varying temperatures. For example, in a car, engine oil must flow freely enough to allow cold starting, but after heating it must be viscous enough to provide complete lubrication. The VI can be determined as described in ASTM D 2270-93.

The pour point and the VI can be coupled to the branching of the paraffinic hydrocarbon molecules of the base lubricating oil. By forming branches on linear paraffinic hydrocarbons, the pour point and the viscosity index (VI) are generally lowered. The VI tends to decrease sharply if the number of substitutions of equal length is doubled, but the pour point is less affected. The data from API Project 42 (research completed between July 1, 1943 and July 1, 1946 by the American Petroleum Institute Research Project 10272 42 ^ * 3 ject 42 at Pennsylvania State College) showed that the VI decreased when the branching to the center of the molecule were shifted for butyl, phenyl and cyclohexyl branches on a linear paraffin.

Waxy hydrocarbons prepared according to a Fischer-Tropsch process 5 are a good possible feed for the preparation of high quality lubricants. Advantageously, the Fischer-Tropsch products contain little or none of the usual petroleum impurities, such as aromatic compounds, sulfur compounds and nitrogen compounds. However, the initial waxy Fischer-Tropsch paraffins are generally straight chain waxes. Therefore, the Fischer-Tropsch products must be subjected to further processing or upgrading to provide the high quality basic lubricating oil raw materials.

Many researchers have investigated ways of converting waxy feeds, in particular waxy feeds from Fischer-Tropsch synthesis processes, into 15 basic lubricating oil raw materials. By way of example, in an attempt to form sufficient branches to lower the pour point but not too many branches so that the VI decreases significantly, the prior art methods employ a combination of hydroisomerization with solvent dewaxing using large-pore amorphous or zeolite catalysts (eg Beta zeolite) for the hydroisomerization step. Nevertheless, with prior art methods employing this technique, a significant degree of branching is still formed.

For example, U.S. Pat. No. 6,090,989 describes a hydro-dewaxing process for preparing basic lubricating oil raw materials. The base lubricant raw materials described therein contain paraffinic hydrocarbon components with the degree of branching, as measured by the percentage of methyl hydrogen (BI), and the proximity of branching, as measured by the percentage of repeating methylene hydrocarbons that are four or more carbon atoms removed from an end group or branch (CH 2> 4) is such that: (a) B1-0.5 (CH2> 4) greater than 15 and (b) B1 + 0.85 (CH2> 4) <45. This calculation means that for a molecule containing 24 carbon atoms, that molecule has at least 2.5 branches per molecule, or for every 100 carbon atoms there are more than about 9 branches.

1027242 11 4

U.S. Pat. No. 6,008,164 describes a process for producing a base lubricant raw material from a Fischer-Tropsch wax, wherein the base lubricant raw material has a preselected oxidation stability. The base lubricating oils are described to contain a mixture of branched paraffins, the branched paraffins containing up to four alkyl branches and the free carbon index (FCI) of the branched paraffins being at least about 3. The examples of U.S. Pat. No. 6008164 show basic lubricating oils with 3.46.3.14.4.19 and 3.59 branches per molecule.

WO 99/45085 describes an integrated process for preparing a basic lubricating oil raw material comprising an isomerization step followed by a solvent dewaxing step. In the process, a waxy feed as described therein is isomerized over a selected molecular sieve to a product with an average pour point and the isomerized oil is then subjected to solvent dewaxing. It is described that the obtained base lubricating oil raw materials have viscosity indices higher than about 140. The examples of WO 99/45085 show basic lubricating oil raw materials with viscosity indices between 140 and 156.

In EP-A2-0776959 a process is described for preparing base lubricating oils with a VI of at least 150 from a Fischer-Tropsch washing feed, which contacting the Fischer-Tropsch washing feed with a hydroconversion catalyst under hydroconversion conditions ; separating the obtained effluent subjected to a hydroconversion into at least a lighter fraction and a heavy fraction; and dewaxing the heavy fraction to obtain the base oil. The feed for the process is closely limited to a Fischer-25 Tropsch wax with a freezing point of at least 50 ° C and with a boiling range in which the difference between the 90 wt.% Boiling point and the 10 wt.% Boiling point in the range is from 40 to 150 ° C. The hydroconversion catalysts are described as amorphous catalysts.

U.S. Pat. No. 6,096,940 describes a process for producing a biodegradable hydrocarbon base lubricating oil. The method comprises contacting a 700 ° F + Fischer-Tropsch wash feed with hydrogen over a bi-functional Group VIII non-noble metal catalyst to give hydroisomerization and hydrocracking reactions at 700 ° F + 1027242 · * 5 conversion levels that vary from about 20 to about 50 percent based on a one-time throughput, based on the weight of the 700 ° F + feedstock converted to 700 ° F materials, to produce a crude C5-1050 ° F fraction. It is described that the isoparaffs present in the crude fraction have methyl branches in an amount of less than about 7.5 methyl branches per 100 carbon atoms. From the C5-1050 ° F fraction, a residual fraction with an initial boiling point ranging from about 650 ° F to about 750 ° F is recovered. The residual fraction is dewaxed and a dewaxed oil is extracted. A biodegradable hydrocarbon base oil is extracted from the dewaxed oil. In the examples, the VI of the base lubricating oil recovered is between 130 and 140.

U.S. Pat. No. 5,059,299 describes a process for maximizing the yield of basic lubricating oil raw materials with pour points of about -21 ° C or lower and a viscosity index of about 130 and higher through the steps of 1) isomerizing the wax over a 15 isomerization catalyst so that between about 15 and 30% of unreacted wax remains in the oil fraction of the isomerate boiling in the boiling range of lubricant, 2) the fractionation of the product, 3) the solvent dewaxing of the fraction boiling in the boiling range of lubricant to a flow / filter delta T (the difference in temperature between the pour point of the dewaxed oil and the filter temperature) of 9 ° C or lower and 4) recovering a dewaxed lubricating oil product. The dewaxing catalysts suitable for use in this invention are broadly defined and include catalysts such as fluorinated alumina.

There has also been research into how the composition of basic lubricating oils should be analyzed and how the properties of basic lubricating oils are influenced by their composition. By way of example, in a publication by Kramer, DC, et al., "Influence of Group & Base Oil Composition on VI and Oxidation Stability" is prepared for presentation at the 1999 AIChE Spring National Meeting in Houston, March 16, 1999 , described that field ionization mass spectrometry (FIMS) is particularly valuable in determining the distribution of paraffins and naphthenes in base oils from groups Π and ΙΠ. With less than 1% aromatics, the authors found that the most effective way to further improve oxidation stability was to increase VI. In general, the 1027242 * 6 authors have found that the lower the concentration of polycyclic naphthenes in an oil, the higher its VI and oxidation stability.

There remains a need for an efficient and economical process for converting waxy paraffinic feeds into high quality base lubricants, in particular base lubricants with good low temperature properties and high viscosity indices.

Summary of the invention The present invention relates to a basic lubricating oil comprising paraffinic hydrocarbon components, the degree of branching being less than 8 alkyl branches per 100 carbon atoms and wherein less than 20% by weight of the alkyl branches are in the 2 position . The basic lubricating oil has a pour point lower than -8 ° C; a kinematic viscosity at 100 ° C of about 3.2 cSt or higher; 15 and a viscosity index higher than a target viscosity index, as calculated according to the following equation:

Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) + 132.

In another aspect, the present invention relates to a base lubricating oil that has a pour point lower than -8 ° C; a kinematic viscosity at 100 ° C higher than 3.2 cSt; and a viscosity index higher than a target viscosity index, as calculated according to the following equation:

Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) + 132.

In yet another aspect, the present invention relates to a ready lubricant. The finished lubricant comprises the basic lubricating oils as described herein and one or more lubricant additives.

In a further aspect, the present invention relates to an oil isomerate intermediate. The oil isomerate intermediate comprises paraffinic hydrocarbon components obtained via Fischer-Tropsch, the degree of branching being less than 7 alkyl branches per 100 carbon atoms.

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Brief description of the drawings

The figure illustrates the graph of the viscosity at 100 ° C versus the viscosity index provided by the equation for calculating the intended viscosity index:

Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) + 132 where ln (kinematic viscosity at 100 ° C) is the natural logarithm of the kinematic viscosity at 100 ° C.

Detailed description of illustrative embodiments

The present invention relates to base lubricating oils comprising a mixture of paraffinic hydrocarbon components, wherein the mixture of paraffinic hydrocarbon components has an optimized branching. These basic lubricating oils comprising a mixture of paraffinic hydrocarbon components with an optimized branching have a low degree of total branching, with the branching concentrated towards the center of the basic lubricating oil molecules. The present invention also relates to processes for producing these base lubricating oils from waxy feeds and commercially available ready lubricants comprising these base lubricating oils.

It has been surprisingly discovered that with base lubricating oils with kinematic viscosities higher than about 3.2 cSt at 100 ° C, an optimized branching can provide extremely low pour points and extremely high viscosity indices, which are higher than the intended viscosity index, as defined herein. Optimized branching according to the present invention means that the basic lubricating oil molecules comprise paraffinic hydrocarbon components with a low degree of branching in total, the branching being concentrated towards the center of the molecules.

Basic lubricating oils comprising paraffinic hydrocarbon components with an optimized branching and kinematic viscosities higher than about 3.2 cSt at 100 ° C can be produced by a combination of a mild hydroisomerization followed by solvent dewaxing. According to the present invention, a waxy feed is subjected to a mild hydroisomerization process under conditions such that an oil isomerate intermediate comprising paraffinic hydrocarbon components with specific branching properties is formed. The oil-isomerate intermediate is then subjected to solvent dewaxing under conditions to provide a basic lubricating oil comprising paraffinic hydrocarbon components with an optimized branching and with a kinematic viscosity higher than about 3.2 cSt at 100 ° C. The method of the present invention results in a base lubricating oil comprising paraffinic hydrocarbon components with an optimized branching such that there is a low degree of branching in total, with the branching concentrated to the center of the molecules. The degree of branching and the position of the branching can be determined by NMR analysis.

It has surprisingly been discovered that by minimizing the total branching while increasing the branching to the center of the basic lubricating oil molecules, a basic lubricating oil with exceptionally high viscosity indices and low pour points is provided. Accordingly, high quality basic lubricating oils with exceptionally high viscosity indices and low pour points are produced.

Definitions 20

The following terms are used throughout the description and have the following meanings unless otherwise stated.

"Obtained from a Fischer-Tropsch synthesis or process" means that the fraction, stream or product in question comes from or is produced at any stage with a Fischer-Tropsch process.

"Waxy hydrocarbon feed" is a feed or stream comprising molecules with a carbon number of C20 + and with a boiling point that is generally higher than about 316 ° C (600 ° F). The waxy hydrocarbon feeds useful in the processes described herein may be synthetic waxy feeds, such as Fischer-Tropsch waxy hydrocarbons, or may be obtained from natural sources such as petroleum waxes.

"Basic lubricating oil" means a fraction or product that meets the specifications for a basic lubricating oil. Basic lubricating oil fractions are provided by a hydroisomerization / solvent dewaxing process according to the methods of the present invention and have optimized branching properties. Additional properties of the base lubricating oils provided in accordance with the present invention include boiling points in the range of 600 to 950 ° F, final boiling points in the range of 800 to 1200 ° F, viscosities in the range of 3.2 to 20 cSt at 100 ° C, viscosity indices in the range of 158 to 240, preferably in the range of 163 to 220 and more preferably in the range of 165 to 200. The base lubricating oils further have pour points lower than -8 ° C, preferably lower than -9 ° C, more preferably ^ -15 ° C and even more preferably lower than -15 ° C and preferably in the range of -8 to 10 -35 ° C. The basic lubricating oils may also have cloud points in the range of +5 to - 20 ° C.

"Hydrocarbon or hydrocarbonaceous" means a compound or substance which contains hydrogen and carbon atoms and which may also contain heteroatoms such as oxygen, sulfur or nitrogen.

"Intended viscosity index" is an empirical number obtained from the kinematic viscosity and the viscosity index. The intended viscosity index is calculated using the following equation:

Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) +132 where ln (kinematic viscosity at 100 ° C) is the natural logarithm of the kinematic viscosity at 100 ° C. The determination of the intended viscosity index is illustrated in the figure.

"Alkyl" means a linear saturated monovalent hydrocarbon radical with one to six carbon atoms or a branched saturated monovalent hydrocarbon radical with three to eight carbon atoms. Preferably the alkyl groups are methyl. Examples of alkyl groups include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and the like.

"Free carbon index" (FCI) is a measure of the number of carbon atoms in an isoparaffin which is at least 5 carbon atoms from a terminal carbon atom and 4 carbon atoms from a side chain.

It has surprisingly been discovered that base lubricating oils with kinematic viscosities higher than about 3.2 cSt at 100 ° C which include paraffinic hydrocarbon components with certain desired branching properties (optimized branching) have extremely high viscosity indices and excellent low pour points. The 10272423 10 viscosity indices of the basic lubricating oils of the present invention are higher than the intended viscosity index of the oil. Preferably, the viscosity indices of the basic lubricating oils according to the present invention are higher than the intended viscosity index of the oil plus 5. As defined above, the intended viscosity index is dependent on the viscosity and is calculated using the following equation:

Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) +132

These basic lubricating oils comprise a mixture of paraffinic hydrocarbon components, the total mixture of paraffinic hydrocarbon components having an optimized branching. These basic lubricating oils comprising paraffinic hydrocarbon components with an optimized branching are produced from waxy feeds. The present invention also relates to oil isomerate intermediates prepared in the processes for preparing the base lubricating oils of the present invention. The oil isomerate intermediates of the present invention include paraffinic hydrocarbon components with specific branching properties. Therefore, when the isomerate intermediates are converted to base lubricating oils, the base lubricating oils comprise paraffinic hydrocarbon components with optimized branching properties. The oil isomerate intermediates consist of paraffinic hydrocarbon components, the paraffinic hydrocarbon components having a low degree of branching overall.

The oil isomerate intermediates are converted to basic lubricating oils consisting of paraffinic hydrocarbon components with optimized branching properties. Optimized branching properties according to the present invention means that the paraffinic hydrocarbon components have a low degree of branching overall, the branching being concentrated towards the center of the molecules. Accordingly, the branching to the ends of the molecules is minimized.

The branches on the paraffinic hydrocarbon components of the base lubricating oils and oil isomerate intermediates are alkyl branches. In the basic lubricating oils and oil isomerate intermediates, the alkyl branches are essentially methyl branches (-CH 3). According to the present invention, the branching properties in the basic lubricating oils are optimized. The branching properties include the degree of branching and the position of the branching. The degree of branching can be measured by the number of alkyl branches per given number of carbon atoms of the paraffinic hydrocarbon components. Preferably, the degree of branching is measured by the number of alkyl branches per 100 carbon atoms. The position of the branch is measured with respect to the ends of the paraffin hydrocarbon chain, with the terminal carbon atoms in the 1 position, the next carbon atom in the 2 position, the next carbon atom in the 3 position location, and so on, until the middle of the hydrocarbon chain is reached. The positions on the hydrocarbon chain can be illustrated as follows: The oil isomerate intermediates are intermediates of the process for preparing the base lubricating oils of the present invention. The oil isomerate intermediates are produced by subjecting a waxy feed to a mild hydroisomerization process using a specific class of shape-selective catalysts that give a high degree of reduction in the pour point with a minimum degree of branching. The oil isomerate intermediates are subjected to solvent dewaxing to provide the base lubricating oils of the present invention.

According to the present invention, the oil isomerate intermediates comprise paraffinic hydrocarbon components with specific branching properties. The oil isomerate intermediates consist of paraffinic hydrocarbon components with a total low branching rate. In particular, the oil isomerate intermediates comprise paraffinic hydrocarbon components with less than 7.0 alkyl branches per 100 carbon atoms and preferably less than 6.5 alkyl branches pa-100 carbon atoms.

The oil isomerate intermediates are subjected to solvent dewaxing to provide the base lubricating oils of the present invention.

According to the present invention, the basic lubricating oils comprise paraffinic hydrocarbon components with the branching optimized. The base lubricating oils comprise paraffmic hydrocarbon components with an optimized branching in that the paraffmic hydrocarbon components of the isomerates have a low total branching total, the branching being concentrated towards the center of the molecules.

In particular, the base lubricating oils comprise paraffinic hydrocarbon components with less than 8 alkyl branches per 100 carbon atoms, preferably less than 7 alkyl branches per 100 carbon atoms and more preferably less than 6.5 alkyl branches per 100 carbon atoms. In addition, the basic lubricating oils comprise paraffinic hydrocarbon components with less than 10% by weight branching in the 2-position and preferably less than 15% branching in the 2-position. The base lubricating oils also have a low degree of branching at the 2- plus 3-positions, preferably less than 25% by weight and more preferably less than 20% by weight. Furthermore, the base lubricating oils have branches in the 5 or higher positions of more than 45% by weight and more preferably more than 50% by weight.

It is generally accepted in the art that it is easier to produce base lubricating oils with low kinematic viscosities, generally lower than about 3.2 cSt at 100 ° C, and with low pour points than it is to produce base lubricating oils with higher kinematic viscosities, which also have desired pour points. The paraffinic hydrocarbon molecules present in base lubricating oils with low kinematic viscosities have relatively short paraffinic chains, generally with a length of less than about 25 carbon atoms. Because base lubricating oils with relatively low kinematic viscosities have relatively short paraffinic chains, these base lubricating oils generally require fewer branches to reach a low pour point.

In contrast, basic lubricating oils with a higher viscosity comprise paraffmic hydrocarbon molecules with a larger chain length. These longer paraffmic hydrocarbon molecules of base lubricating oils with a higher viscosity are much more difficult to isomerize to a low degree of branching and it is difficult to obtain a low pour point.

In addition, it has previously been demonstrated that if branches go to the center of linear paraffins for butyl, phenyl and cyclohexyl branches, the VI decreases. Therefore, it was not considered desirable to produce a base lubricating oil with the placement of the branches towards the center of the paraffinic molecule and it is quite surprising that by doing so, combined with the low degree of branching, a base lubricating oil with exceptionally high VTs and low pour points.

According to the methods of the present invention, waxy feeds are processed in such a way that this desired degree and placement of branching is achieved (i.e., optimized branching). Therefore, base lubricating oils with high viscosities, low pour points and exceptionally high VIs are produced. The base lubricating oils of the present invention have kinematic viscosities at 100 ° C higher than about 3.2 cSt, preferably between about 3.2 cSt and about 20 cSt. In addition, the base lubricating oils of the present invention comprise average carbon numbers higher than about 27, preferably higher than about 30 and more preferably higher than about 27 and lower than about 70.

The degree of branching and the location of the branching can be determined by NMR analysis.

NMR branching analysis

The branching properties of the base lubricating oils and oil isomerate intermediates of the present invention are determined by analyzing a sample of the oil using carbon 13 NMR according to the following eight-step method. References cited in the description of the method provide details regarding the process steps. Steps 1 and 2 are carried out only with the initial materials of a new process.

1.) Identify the centers of the CH branch and the end points of the CH3 branch using the DEPT Pulse sequence (Doddrell, D.T .; D.T. Pegg; M. R. Bendall, Journal of Magnetic Resonance 1982,48, 323 et al.).

2.) Verify the absence of carbon atoms that initiate multiple branches (quaternary carbon atoms) using the APT pulse sequence (Patt, S.L .; J.N. Shoolery, Journal of Magnetic Resonance 1982, 46,535 et seq.).

3.) Assign the different carbon resonances of the branch to specific branch positions and lengths using tabulated and calculated 1027242 14 values (Lindeman, LP, Journal of Qualitative Analytical Chemistry 43, 1971, 1245 et seq., Netzel, DA, et al., Fuel, 60.1981, 307 et seq.).

Examples:

Branching NMR chemical shift (ppm) 5 2-methyl 22.5 3-methyl 19.1 or 11.4 4-methyl 14.0 4 + methyl 19.6 internal ethyl 10.8 propyl 14.4

Neighboring methyl groups 16.7.) Quantify the relative frequency of branching occurrence at different carbon positions by comparing the integrated intensity of its terminal methyl carbon atom with the intensity of a single carbon atom (= total integral / number of carbon atoms per molecule in the mixture).

For the unique case of the 2-methyl branch, where both the terminal and branched methyl occur at the same resonance position, the intensity was divided by two before the branch occurrence frequency calculation was performed.

If the 4-methyl branching fraction is calculated and tabulated, the contribution thereof must be deducted from the 4+ methyls in order to avoid double counting.

5.) Calculate the free carbon index using the calculated average carbon number of the sample and the results of the C-13 NMR analysis, as described in EP 1062305. The free carbon index (FCI) is a measure of the number of carbon atoms in an isoparaffin that at least 5 carbon atoms of a terminal carbon atom and 4 carbon atoms of a side chain are removed. The average carbon number can be determined with sufficient accuracy for lubricant materials by dividing the molecular weight of the sample by 14 (the weight of the formula (%). The molecular weight can be determined according to ASTM D2502, ASTM D2503 or other suitable methods. According to the present invention, the molecular weight is preferably determined according to ASTM D2503-02.

1027242 w 6. Calculate the branching index (B1) and branching proximity (BP) using the calculations described in U.S. Pat. No. 60,990,989. The branching index is the ratio of the percentage of non-benzyl methyl hydrogen atoms in the range of 0 5 to 1.05 ppm to the total non-benzyl aliphatic hydrogen atoms in the range of 0.5 to 2.1 ppm. The branching proximity is the% equivalent, repeating methylene carbon atoms, which are five or more removed from an end group or branch (epsilon carbon atoms).

7.) The number of branches per molecule is the sum of the branches found in step 4.

8.) The number of alkyl branches per 100 carbon atoms is calculated from the number of branches per molecule (step 7) times 100 / the number of carbon atoms per molecule.

The measurements can be performed using any Fourier-15 Transform NMR spectrometer. Preferably, the measurements are performed using a spectrometer with a magnet of 7.0T or larger. In all cases, after verification by mass spectrometry, UV or an NMR study that aromatic carbon atoms were absent, the spectral width was limited to the saturated carbon range, about 0-80 ppm relative to TMS (tetramethylsilane). Solutions of 15-25% by weight in chloroform-dl were excited by 45 ° pulses, followed by a determination time of 0.8 seconds. In order to minimize non-uniform intensity data, the proton decoupler was turned off during a 10 second delay for the excitation pulse and turned on during the assay. The total duration of the experiment varied from 11-80 minutes. The DEPT and APT sequences were performed according to the descriptions in the literature, with minor deviations described in the Varian or Braker operating manuals.

DEPT is distortion-free amplification through polarization transfer. DEPT shows no quaternary connections. The DEPT-45 sequence gives a signal of all carbon atoms that are bound to protons. DEPT-90 only shows CH carbon atoms. DEPT-135 shows CH and CH3 on and CH2180 degrees out of phase (below). APT is confirmed proton test. This allows all carbon atoms to be observed, but if CH and CH3 are up, then quaternary compounds and CH2 are below. The sequences are useful in that each methyl branch must have a 1027242 ** 16 corresponding CH. And the methyl groups are clearly identified by the chemical shift and phase. Both are described in the cited references.

The branching properties of each sample were determined by C-13 NMR using the assumption in the calculations that the complete sample of the base lubricating oil or the oil isomerate intermediate was isoparafic. No corrections were made for n-paraffins or naphthenes, which may be present in the oil samples in various amounts. The% total naphthenes in the base lubricating oils was generally low or absent due to the mild hydroisomerization dewaxing method used in the preparation. The naphthenic content can be measured using field ionization mass spectroscopy (FIMS).

Nutrition According to the present invention, the feed for the process for producing base lubricating oils with an optimized branching is a waxy hydrocarbon feed. The waxy hydrocarbon feeds useful in the processes described herein may be synthetic waxy feeds, such as waxy Fischer-Tropsch hydrocarbons, or may be obtained from natural sources such as petroleum waxes. Therefore, the waxy feeds for the processes obtained via Fischer-Tropsch can be waxy feeds, petroleum waxes, waxy distillate raw materials such as gas oils, lubricating oil raw materials, poly-alpha olefins with a high pour point, foot oils, normal alpha olefin waxes, slag washing, de-oiled waxes and microcrystalline waxes, and mixtures thereof. Preferably, the waxy feeds are obtained from waxy Fischer-Tropsch feeds. A substantial portion of the waxy feed consists of molecules with a carbon number of C20 + and has a boiling point that is generally higher than about 316 ° C (600 ° F). The majority of the molecules in the waxy feed are higher molecular weight n-paraffins and slightly branched paraffins that contribute to the waxy nature of the feed.

The waxy hydrocarbon feed may, if desired, be hydrotreated for the process described herein.

1027242 "" 17

Fischer-Tropsch synthesis

Preferably, the waxy feeds of the present invention are obtained from waxy Fischer-Tropsch feeds. In Fischer-Tropsch chemistry, syngas is converted into liquid hydrocarbons by contact with a Fischer-Tropsch catalyst under reactive conditions. Typically, methane and optionally heavier hydrocarbons (ethane and heavier) can be passed through a conventional syngas generator to provide synthesis gas. In general, synthesis gas contains hydrogen and carbon monoxide and it may comprise small amounts of carbon dioxide and / or water. The presence of sulfur, nitrogen, halogen, selenium, phosphorus and arsenic contaminants in the syngas is undesirable. Therefore, and depending on the quality of the syngas, it is preferable to remove sulfur and other contaminants from the feed before the Fischer-Tropsch chemistry is performed. Means for removing these contaminants are known to those skilled in the art. ZnO protection beds are, for example, preferred for the removal of sulfur contaminants. Means for removing other contaminants are known to those skilled in the art. It may also be desirable to purify the syngas for the Fischer-Tropsch reactor to remove carbon dioxide produced during the syngas reaction and additional sulfur compounds that have not yet been removed. This can be done, for example, by contacting the syngas with a moderately alkaline solution (e.g., aqueous potassium carbonate) in a packed column.

In the Fischer-Tropsch process, contacting a synthesis gas comprising a mixture of H 2 and CO with a Fischer-Tropsch catalyst produces liquid and gaseous hydrocarbons under suitable reaction conditions of temperature and pressure . The Fischer-Tropsch reaction is usually conducted at temperatures of about 149 to 371 ° C (300 to 700 ° F), preferably about 204 to 228 ° C (400 to 550 ° F); pressures of about 0.7 to 41 bar (10 to 600 psia), preferably 2 to 21 bar (30 to 300 psia); and catalyst space rates of from about 100 to about 10,000 cm 3 / g / hour, preferably about 300 to 3,000 cm 3 / g / hour. Examples of conditions for carrying out Fischer-Tropsch type reactions are known to those skilled in the art.

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The products of the Fischer-Tropsch synthesis process can range from C 1 to C 200 +, with the majority in the C5-Q00 + range. The reaction can be conducted in a variety of reactor types, such as fixed bed reactors that have one or more catalyst beds. containing, suspension reactors, fluidized bed reactors, or a combination of different types of reactors. Such reaction processes and reactors are known and documented in the literature.

In the Fischer-Tropsch suspension process, which is preferred in the practice of the invention, superior heat (and mass) transfer characteristics are used for the highly exothermic synthesis reaction and paraffinic hydrocarbons with a relatively high molecular weight can be produced as a cobalt catalyst is used. In the slurry process, a syngas comprising a mixture of hydrogen and carbon monoxide is bubbled upwards as a third phase through a slurry in a reactor comprising a particulate hydrocarbon-synthesis catalyst of the Fischer-Tropsch type that is dispersed and dispersed. suspended in a suspending liquid comprising hydrocarbon products of the synthesis reaction which are liquid under the reaction conditions. The molar ratio of hydrogen to carbon monoxide can vary roughly from about 0.5 to 4, but more usually is in the range of about 0.7 to about 2.75 and preferably from about 0.7 to about 2.5. A particularly preferred Fischer-Tropsch process is described in EP 0609079, which should also be considered as fully incorporated herein for all purposes.

In general, Fischer-Tropsch catalysts contain a Group Vin transition metal on a metal oxide support. The catalysts may also contain (a) noble metal promoter (s) and / or crystalline molecular sieves. Suitable Fischer-25 Tropsch catalysts include one or more of the metals Fe, Ni, Co, Ru, and Re, with cobalt being preferred. A preferred Fischer-Tropsch catalyst comprises effective amounts of cobalt and one or more of the metals Re, Ru, Pt, Fe, Ni, Th, Zr, Hf, U, Mg and La on a suitable inorganic support material, preferably a carrier material comprising one or more refractory metal oxides. In general, the amount of cobalt present in the catalyst is between about 1 and about 50 percent by weight of the total catalyst composition. The catalysts may also include basic oxide promoters such as TI102, La2O3, MgO and T102, promoters such as Ζ1Ό2, noble metals (Pt, Pd, Ru, Rh, Os, Ir), coin metals (Cu, Ag, Au) and others 1027242 "* 19 contain transition metals such as Fe, Mn, Ni and Re. Suitable support materials include alumina, silica, magnesium oxide, and titanium oxide or mixtures thereof. Preferred supports for cobalt-containing catalysts include titanium oxide. Useful catalysts and their preparation are known and are illustrated in U.S. Patent No. 4,566,863, which is intended to be illustrative, but not limiting, of the choice of catalyst.

Certain catalysts are known to provide chain growth probabilities that are relatively low to medium and the reaction products include a relatively high content of low molecular weight olefins (C2-8) and a relatively low content of high molecular weight waxes (C3 <h) . Certain other catalysts are known to provide relatively high chain growth probabilities and the reaction products include a relatively low content of low molecular weight olefins (C2-8) and a relatively high content of high molecular weight waxes (C30 +). Such catalysts are known to the person skilled in the art and can easily be obtained and / or prepared.

The product of a Fischer-Tropsch process contains mainly paraffins. The products of Fischer-Tropsch reactions generally include a light reaction product and a waxy reaction product. The light reaction product (ie the condensate fraction) comprises hydrocarbons boiling at a temperature below about 700 ° F (eg tail gases up to medium distillate fuels), largely in the range of C5 -C20> with decreasing amounts up to about C30 · The waxy reaction product (ie the wash fraction) includes hydrocarbons boiling at a temperature above about 600 ° F (eg vacuum gas oil up to heavy paraffins), largely in the range of C20 +, with decreasing amounts up to C10-25 Both the light reaction product and the waxy product are essentially paraffinic. The waxy product generally comprises more than 70% by weight of normal paraffins and often more than 80% by weight of normal paraffins. The light reaction product comprises paraffinic products with a significant content of alcohols and olefins. In some cases, the light reaction product may comprise as much as 50% by weight, and even 30 more, of alcohols and olefins. It is the waxy reaction product (i.e., the wax fraction) that can be used as a feed for the methods of the present invention.

1 027242 · * 20

Hydroisomerization

According to the present invention, the waxy hydrocarbon feedstock is subjected to hydroisomerization in a hydroisomerization zone to produce an oil isomerate intermediate.

Hydroisomerization is intended to improve the cold flow properties of a base lubricating oil by selectively adding branching to the molecular structure. With hydroisomerization dewaxing, high conversion levels of waxy feed to non-waxy isoparaffins are ideally achieved while at the same time reducing cracking conversion.

According to the present invention, the hydroisomerization is carried out using a shape-selective molecular sieve with an average pore size. Hydroisomerization catalysts useful in the present invention include a shape-selective molecular sieve with an average pore size and optionally a hydrogenation component of a catalytically active metal on a refractory oxide support. The term "average pore size," as used herein, means an effective pore opening in the range of about 4.0 to about 7.1 A if the porous inorganic oxide has a calcined form. The shape-selective molecular sieves with an average pore size used in the embodiment of the present invention are generally molecular sieves with a 1-D 10, 11 or 12 ring. The preferred molecular sieves according to the invention are of the 1-D 10-ring variety, with molecular sieves having a 10- (or 11- or 12-) ring 10 (or 11 or 12) tetrahedrically coordinated atoms (T atoms) that are bound to oxygen atoms. In the 1-D molecular sieve, the 10-ring (or larger) pores are parallel to each other and do not form an interconnection. The classification of intrazeolite channels as 1-D, 2-D and 3-D is represented by R.M. Barrer in Zeolites, Science and Technology, published by F.R. Rodrigues, L.D. Rollman and C. Naccache, NATO ASI Series, 1984, which classification in its entirety is to be regarded as incorporated herein (see in particular page 75). Shape-selective molecular sieves with an average pore size that are used for hydroisomerization are based on aluminum phosphates, such as SAPO-11, SAPO-31 and SAPO-41. SAPO-11 and SAPO-31 are more preferred, with SAPO-11 being the most preferred. SM-3 is a particularly preferred 10272 42 "'21 shape-selective medium pore size SAPO and has a crystal structure that falls within that of the SAPO-11 molecular sieves. The preparation of SM-3 and its unique properties are described in U.S. Patent Nos. 4,943,424 and 5,158,665. Also preferred form-selective molecular sieves with an average pore size and used for hydroisomerization are zeolites such as ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, SSZ-32, offretite and ferrierite . SSZ-32 and ZSM-23 are more preferred.

A preferred average pore size molecular sieve is characterized by selected crystallographic free diameters of the channels, selected crystal size (corresponding to a selected channel length) and selected acidity. Desired crystallographic free diameters of the channels of the molecular sieves are in the range of about 4.0 to about 7.1 Angstroms, with a maximum crystallographic free diameter of no more than 7.1 and a minimum crystallographic free diameter of no less than 3.9 Angstrom. Preferably, the maximum crystallographic free diameter is not greater than 7.1 and the minimum crystallographic free diameter is not less than 4.0 Angstroms. Most preferably, the maximum crystallographic free diameter is not greater than 6.5 and the minimum crystallographic free diameter is not less than 4.0 Angstroms. The crystallographic free diameters of 20 channels of the molecular sieves are published in the "Atlas of Zeolite Frame-work Types", fifth revised edition, 2001, of Ch. Baerlocher, W.M. Meier and D.H. Olson, Elsevier, pp. 10-15, which is incorporated herein by reference.

A particularly preferred average pore size molecular sieve useful in the present process is described, for example, in U.S. Patent Nos. 5,113,538 and 5,228,958, the contents of which are incorporated by reference in their entirety. In U.S. Pat. No. 5,228,958, such an average pore size molecular sieve has a crystal size of no more than about 0.5 microns and pores with a minimum diameter of at least about 4.8 A and a maximum diameter of about 7.1 A. The catalyst has a sufficient acidity, so that at least 50 grams of this if it is placed in a tube reactor at 370 ° C, a pressure of 1200 psig, a hydrogen flow rate of 160 ml / min and a feed rate of 1 ml / hour % hexadecane turnover. The catalyst also exhibits an isomerization selectivity of 40 percent or higher (the 10272 42 '' '22 isomerization selectivity is determined as follows: 100 x (wt% branched C16 in product) / (wt% branched C16 in product + % by weight of C13 -in product) when used under conditions leading to a conversion of 96% normal-hexadecane (n-C10) to other species).

Such a particularly preferred molecular sieve can be further characterized by pores or channels with a crystallographic free diameter in the range of about 4.0 to 7.1 A and preferably in the range of 4.0 to 6.5 A The crystallographic free diameters of the channels of molecular sieves are published in the "Atlas of Zeolite Framework Types", fifth revised edition, 2001, of Ch. Baerlocher, W.M. Meier and D.H., Olson, Elsevier, pp. 10-15, which is incorporated herein by reference.

If the crystallographic free diameters of the channels of a molecular sieve are unknown, the effective pore size of the molecular sieve can be measured using standard adsorption techniques and hydrocarbonaceous compounds with known minimum kinetic diameters. See Breek, Zeolite Molecu-lar Sieves, 1974 (in particular Chapter 8); Anderson et al., J. Catalysis 58, 114 (1979); and U.S. Patent No. 4,440,871, the relevant parts of which are incorporated herein by reference. Standard techniques are applied when conducting adsorption measurements to determine the pore size. It is suitable to consider a particular molecule as excluded if it does not reach at least 95% of its equilibrium adsorption value on the molecular sieve in less than about 10 minutes (p / p0 = 0.5; 25 ° C). Molecular sieves with a medium pore size usually allow molecules with kinetic diameters of 5.3 to 6.5 Angstroms with little steric hindrance.

Hydroisomerization catalysts useful in the present invention optionally include a catalytically active bydrogenation metal. The presence of a catalytically active bydrogenation metal leads to product improvement, in particular VI and stability. Typically, catalytically active hydrogenation metals include chromium, molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum, and palladium. The metal platinum and palladium are particularly preferred, with platinum being very particularly preferred. When platinum and / or palladium is used, the total amount of the active hydrogenation metal is usually in the range of 0.1 to 10272 42 "* 23 5% by weight of the total catalyst, usually 0.1 to 2% by weight, and not more than 10 weight percent.

The carrier of a refractory oxide can be selected from those oxide carriers, which are commonly used for catalysts, including silica, alumina, silica-alumina, titania and combinations thereof.

The conditions for the hydroisomerization are adjusted to achieve an isomerized oil intermediate with specific branching properties, as described above, and thus depend on the properties of the feed used. In general, the conditions for the hydroisomerization in the present invention are mild, so that the conversion of wax to materials boiling at a temperature below about 700 ° F is kept below about 35% by weight in producing the oil. isomerate intermediates.

Mild hydroisomerization conditions are achieved by operating at a lower temperature, generally between approximately 390 ° F and 650 ° F, at an LHSV which is generally between approximately 0.5 hours -1 and approximately 20 hours -1 . The pressure is usually about 15 psig to about 2500 psig, preferably about 50 psig to about 2000 psig, more preferably about 100 psig to about 1500 psig. Low pressure provides improved isomerization selectivity, which results in more isomerization and less cracking of the feed, thus obtaining a higher yield.

Hydrogen is present in the reaction zone during the hydroisomerization process, usually in a hydrogen to feed ratio of about 0.5 to 30 MSCF / bbl (thousand standard cubic feet per vessel), preferably about 1 to about 10 MSCF / bbl . Hydrogen can be separated from the product and returned to the reaction zone.

These mild hydroisomerization conditions employing medium pore size shape selective molecular sieves give oil isomerate intermediates comprising paraffinic hydrocarbon components with specific branching properties, i.e. have a low degree of branching overall.

1027242 "24

As described above, the oil isomerate intermediates have less than 7.0, preferably less than 6.5, alkyl branches per 100 carbon atoms, as determined by NMR branch analysis.

5 Solvent dewaxing

According to the present invention, the oil isomerate intermediates are subjected to solvent dewaxing to produce base lubricating oils comprising paraffinic hydrocarbon components with optimized branching properties. Thus, the solvent dewaxing gives base lubricating oils that include paraffinic hydrocarbon components that have a low total branching degree, with the branching concentrated to the center of the molecules.

Solvent dewaxing is used to remove the remaining waxy molecules from the oil isomerate intermediate by dissolving the oil isomerate intermediate in a solvent such as methyl ethyl ketone, methyl isobutyl ketone or toluene, or precipitating the wax molecules such as is discussed in Chemical Technology of Petroleum, third edition, William Gruse and Donald Stevens, McGraw-Hill Book Company, Ine., New York, 1960, pages 566 to 570. See also U.S. Patent Nos. 4477333, 3773650 and 3775288. In this invention, solvent dewaxing is advantageously applied after the hydroisomerization to recover unreacted wax after the hydroisomerization under mild conditions, the conversions of the wax in material boiling at a temperature below about 700 ° F being less than about 35 %.

According to the present invention, solvent dewaxing can be carried out according to conventional methods known to those skilled in the art. Solvent dewaxing can be carried out by cooling oil isomerate intermediate / solvent mixtures under controlled conditions for crystallization of the paraffinic wax present in the mixtures. In such processes, the oil isomerate intermediate and the dewaxing solvent are heated to a temperature at which the wax dissolves. The heated charge is then supplied to a cooling zone where cooling takes place at an evenly low speed in the range of about 0.5 ° to 4.5 ° C / min until a temperature is reached (eg -10 ° to 1027242 -20 ° C) wherein a substantial portion of the wax crystallizes and the dewaxed base lubricating oil product has a selected pour point temperature. Upon reaching the desired dewaxing temperature, the mixture of wax crystals, oil-isomerate intermediate, and solvent is subjected to solid-liquid separation to recover a wax-free oil-solvent solution and a solid wax containing a low oil content contains. Solid-liquid separation techniques that can be used to separate the wax crystals from the oil-solvent solutions include known solid-liquid separation methods, such as gravity settling, centrifugation, and filtration. Typically, in commercial processes, filtration in a rotary vacuum filter, followed by washing with a solvent of the wax cake, is used. The solid wax / oil solution obtained after the separation of the solid wax is known as slag wax.

The separated oil-solvent solution is subjected to distillation to recover a solvent fraction and a dewaxed basic lubricating oil product fraction. This method is as described in U.S. Patent No. 5,413,695, the contents of which are incorporated by reference in their entirety.

Solvents known to be useful as dewaxing solvents are ketones containing 3 to 6 carbon atoms, such as, for example, acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), mixtures of ketones and mixtures of ketones with aromatic hydrocarbons, including benzene and toluene. Low molecular weight halogenated hydrocarbons, including dichloromethane and dichloroethane, and mixtures thereof are also known as dewaxing solvents. By diluting a waxy oil base with a solvent, the fluidity of the oil is retained to facilitate handling, to obtain optimum wash-oil separation, and to obtain optimum yields of the dewaxed oil. The degree of dilution with a solvent depends on the particular oil isomerate intermediate raw materials and solvents used, the approximation of the filtration temperature in the cooling zone and the desired final solvent to oil ratio in the separation zone.

All or part of the wax removed in the dewaxing step can be recovered and returned to the hydroisomerization step for application 1027242-26 in the process of the present invention and / or collected for other applications (e.g. for processing into or application as a salable wax). Upon recycling all recovered wax or a portion of the recovered wax, the wax may only be subjected to the hydroisomerization step of the present invention or may be combined with another waxy feed. By recycling all the recovered wax or part of the recovered wax, the yield of the process increases.

After solvent dewaxing, a basic lubricating oil comprising paraffinic hydrocarbon components with an optimized branching is provided. Optimized branching means that the basic lubricating oil comprises paraffinic hydrocarbon components with a low degree of branching in total, the branching being concentrated towards the center of the molecules. The basic lubricating oils comprising paraffinic hydrocarbon components with an optimized branching recovered from the process of the present invention have a kinematic viscosity at 100 ° C higher than about 3.2 cSt. In addition, the base lubricating oils comprising paraffinic hydrocarbon components with an optimized branching have viscosity indices higher than the intended viscosity indices of the oil, as defined above. Preferably, the viscosity indices of the base lubricating oils of the present invention are higher than the intended viscosity index of the oil plus 5. The base lubricating oils also have a pour point lower than -8 ° C, preferably lower than -9 ° C, more preferably ^ -15 ° C and even more preferably lower than -15 ° C.

In general, the difference in pour points between the pour point of the base lubricating oil and the oil isomerate intermediate for solvent dewaxing is greater than about 25 ° F.

Hvdrofinishen

The base lubricating oil comprising paraffinic hydrocarbon components with an optimized branching, or optionally the oil isomerate intermediate, can be subjected to hydrofinishing in order to improve the quality and stability of the product. During hydrofinishing, the total LHSV is about 0.25 to 2.0, preferably about 0.5 to 1.0. The hydrogen partial pressure is higher than 200 1027242 "27 psia and preferably ranges from about 500 psia to about 2000 psia. The hydrogen recycling rates are usually higher than 50 SCF / Bbl and are preferably between 1000 and 5000 SCF / Bbl. Temperatures range from about 300 ° F to about 750 ° F and preferably range from 450 ° F to 600 ° F.

Suitable hydrofinish catalysts include Group VIIIA noble metals (according to the International Union of Pure and Applied Chemistry rules from 1975), such as platinum or palladium on an aluminum oxide or silicon-containing matrix, and unsulfurized Group VIHA and Group VIB metals, such as nickel molybdenum or nickel-tin on an aluminum oxide or silicon-containing matrix. U.S. Pat. No. 3,852,207 describes a suitable noble metal catalyst and mild conditions. Other suitable catalysts are described, for example, in U.S. Patent No. 4157294 and U.S. Patent No. 3904513. The non-noble metal (such as nickel-molybdenum and / or tungsten, and at least about 0.5 and generally about 1 to about 15 weight percent nickel and / or cobalt, determined as the corresponding oxides. The noble metal (such as platinum catalyst contains more than 0.01 percent metal, preferably between 0.1 and 1.0 percent metal, and combinations of precious metals can also be used, such as blends of platinum and palladium.

20 basic lubricating oils with optimized branching

The basic lubricating oils of the present invention include paraffinic hydrocarbon components where the branching is optimized. The basic lubricating oils comprising paraffinic hydrocarbon components with an optimized branching have high viscosities, low pour points and exceptionally high VIs. The base lubricating oils of the present invention have kinematic viscosities at 100 ° C higher than about 3.2 cSt and preferably between about 3.2 cSt and about 20 cSt. In addition, the base lubricating oils of the present invention comprising paraffinic hydrocarbon components have average carbon numbers higher than about 27, preferably higher than about 30, and more preferably higher than about 27 and lower than about 70.

The American Petroleum Institute (API) has classified base oils according to their chemical composition. As defined by the API, the oils from group 7027242 ^ 28 ΠΙ are oils with a very high viscosity index (> 120) with a total sulfur content lower than 300 ppm and a content of saturated compounds higher than or equal to 90%. API Group ΙΠ oils are also traditionally prepared by vigorous hydrocracking and / or isomerization of the wax. Base lubricating oils according to the present invention are generally classified as base oils from API group ΠΙ. When prepared from waxy feeds with a low total sulfur content, such as Fischer-Tropsch feeds, the base lubricating oils also have a total sulfur content of less than 300 ppm.

Base lubricating oils according to the present invention prepared from waxy Fischer-Tropsch feeds generally have total sulfur levels below about 5 ppm, levels of saturated compounds higher than 95%, and total naphthen levels between zero and about 8% and preferably between zero and about 5%. Total sulfur is determined using ultraviolet fluorescence according to ASTM D 5453-00.

In particular, the base lubricating oils comprise paraffinic hydrocarbon components with less than 8 alkyl branches per 100 carbon atoms, preferably less than 7 alkyl branches per 100 carbon atoms and more preferably less than 6.5 alkyl branches per 100 carbon atoms. The branching at the second position, as determined by NMR branching analysis, is less than 20% by weight, preferably less than 15% by weight. The branching at the two plus three positions is less than 25% by weight, preferably less than 20% by weight. In addition, the branching at the five or higher positions is more than 50% by weight, preferably more than 60% by weight. The free carbon indices of the base lubricating oils of the present invention are generally higher than about 3 and preferably higher than about 5.

The base lubricating oils of the present invention include paraffinic hydrocarbon components in which the degree of branching, as measured by the percentage of methyl hydrogen (B1), and the proximity of the branching, as measured by the percentage of repeating methylene carbon atoms containing four or more 30 carbon atoms be removed from an end group or branch (CH2> 4), such that B1.5 (CH2> 4) is less than 12, while low pour points are maintained. Preferably, the base lubricating oils of the present invention have a 1027242 n 29 branch such that B1 0.5BP is less than 10, more preferably less than 8, and even more preferably less than 6, while maintaining the low pour points .

The pour point is the temperature at which a sample of the basic lubricating oil begins to flow under carefully controlled conditions. Where the pour point is given herein, unless determined otherwise, this is determined according to the standard analytical method ASTM D 5950-02. The base lubricating oils with optimized branching according to the present invention have excellent pour points. The pour points of the base lubricating oils are lower than -8 ° C, preferably lower than -9 ° C, more preferably ^ -15 ° C and even more preferably lower than -15 ° C.

The cloud point is a measure that is complementary to the pour point and is represented as the temperature at which a sample of the base lubricating oil begins to develop a haze under carefully specified conditions. The cloud point can, for example, be determined in accordance with ASTM D 5773-95. The base lubricating oils with an optimized branching according to the present invention have cloud points lower than 0 ° C.

The viscosity indices of the basic lubricating oils comprising paraffinic hydrocarbon components with an optimized branching are extremely high and are higher than the target viscosity index of the basic lubricating oil, preferably higher than the target viscosity index of the basic lubricating oil plus 5. The range of the kinematic viscosities of the basic lubricating oils with an optimized branching is higher than 3.2 cSt at 100 ° C and can be between about 3.2 cSt and about 20 cSt at 100 ° C.

The% total wettenes in the base lubricating oils is generally low or absent due to the mild hydroisomerization dewaxing process used in the preparation. If naphthenes are present, the naphthenes are generally present almost exclusively as mononaphthenes. In the base lubricating oils, the total amount of naphthenes present is between zero and about 8% by weight and preferably between zero and about 5% by weight. The naphthenes are measured using Field Ionization Mass Spectroscopy (F1MS), as described in the publication of Kramer, DC, et al., "Influence of Group II & Base Oil Composition on VI and Oxidation Stability" prepared for presentation at the 1999 AIChE Spring National Meeting in Houston, March 16, 1999. The percentage of total naphthenic content of the base lubricating oils of this invention is determined by taking the sum of 1027242 and 30% mononaphthenes,% dinaphthenes,% trinaphthenes,% tetranaphtenes % pentanaphthenes and% hexanaphthenes, as measured by FIMS for each sample.

Because the base lubricating oils of the present invention contain extremely low amounts of aromatics and multi-ring naphthenes, the base lubricating oils have superior oxidation stability. One way to measure the oxidation stability of base lubricating oils is the oxidizer BN test, as described in U.S. Pat. No. 3,852,207. The oxidizer BN test measures the resistance to oxidation through a Domte type oxygen absorption device . R.W. Dept. "Oxidation of White Oils," Industrial and Engineering Chemistry, Vol. 28, page 26, 10, 1936. Usually, the conditions are an atmosphere of pure oxygen at 340 ° F.

The results are reported in number of hours until 1000 ml of O2 is absorbed by 100 g of oil. In the oxidizer BN test, 0.8 ml of catalyst is used per 100 grams of oil and an additive package is included in the oil to be tested. The catalyst is a mixture of soluble metal naitenates in kerosene, simulating the average metal analysis of crank oil used. The concentrations of the metals in the catalyst are as follows: copper = 6927 ppm; iron = 4083 ppm; lead = 80,208 ppm; manganese = 350 ppm; and tin = 3565 ppm. The additive package is 80 millimoles of zinc bispolypropylene phenyldithiophosphate per 100 grams of oil to be tested. Oxidator BN measures the response of a basic lubricating oil in a simulated application. High values, or long times for absorbing a liter of oxygen, indicate good oxidation stability. For general application, it is desired that the oxidizer BN of a base lubricating oil be longer than 7 hours. For the base lubricating oils of the present invention, the oxidizer BN value is longer than about 15 hours, preferably longer than about 30 hours.

25

Mixtures

The base lubricating oils of the present invention can be used alone or can be mixed with additional base oils selected from the group consisting of conventional base oils from group I, customary base oils from group Π, customary base oils from group III, isomerized petroleum wax, polypropylene alpha-olefins (PAO), poly-internal-olefins (PIO), di-esters, polyol esters, phosphate esters, alkylated aromatics and mixtures thereof.

1 0272-4-2 ^ 31

Alkylated aromatics are synthetic lubricants produced by the alkylation of aromatics with halogen alkanes, alcohols or olefins in the presence of a Lewis or Bronstead acid catalyst. An overview of alkylated aromatic lubricants is provided in Synthetic Lubricants 5 and High-Performance Functional Fluids, published by Ronald L. Shubkin, 1993, pp. 125-144, which is incorporated herein by reference. Useful examples of alkylated aromatics are alkylated naphthalene and alkylated benzene. Alkylated aromatics have good low temperature properties and can provide improved additive solubility and performance in blends with other base oils.

Because the base lubricating oils of the present invention have excellent cold flow properties, high VIs and high oxidation stability, they are ideal blending raw materials for working up conventional base lubricating oils.

It is preferred that when the base lubricating oils of the present invention are mixed with one or more additional base lubricating oils, the additional base oils being present in an amount less than 95% by weight of the total base oil composition obtained.

Ready lubricants 20

Base lubricating oils are the most important component of finished lubricants and they generally represent more than 70% of the finished lubricants. Ready lubricants include a basic lubricating oil and at least one additive. Ready lubricants can be used in cars, diesel engines, axles, transmissions and industrial applications. Ready lubricants must meet the specifications for their intended use, as defined by the relevant regulatory organization.

The basic lubricating oils of the present invention are useful in commercial ready lubricants. As a result of the excellent VTs and low temperature properties thereof, the basic lubricating oils are according to the invention. The present invention is suitable for formulating finished lubricants intended for many of these applications. In addition, the excellent oxidation stability of the base lubricating oils of the present invention makes them useful in ready lubricants for many high temperature applications.

Additives that can be mixed with the base lubricating oil of the present invention to provide a finished lubricant composition include those intended to improve selected properties of the finished lubricant. Typical additives include, for example, anti-wear additives, EP agents, detergents, dispersants, antioxidants, agents that lower the pour point, agents for improving the VI, agents for modifying the viscosity, agents for modifying the friction , demulsifiers, anti-foaming agents, corrosion inhibitors, rust inhibitors, swelling sealing agents, emulsifiers, wetting agents, lubricating enhancing agents, metal deactivators, gelling agents, tackifiers, bactericides, anti-fluid loss additives, colorants and such.

Other hydrocarbons, such as those described in U.S. Pat. Nos. 5096883 and 5189012, may be mixed with the base lubricating oil, provided that the finished lubricant has the necessary pour point, kinematic viscosity, flash point and toxicity properties. These other hydrocarbons include base oils that are particularly useful in drilling fluids. For example, U.S. Patent No. 5096883 relates to a substantially non-toxic base oil consisting essentially of branched paraffins or branched paraffins substituted with an ester functionality, or mixtures thereof, the base oil preferably being between about 18 and about 40 carbon atoms per molecule and more preferably between about 18 and about 32 carbon atoms per molecule. United States Patent No. 5189012 relates to synthetic hydrocarbons selected from the group consisting of branched oligomers synthesized from one or more olefins containing a C2 to C14 chain and the oligomers having an average molecular weight of 120 to 1000 .

Typically, the total amount of additives in the finished lubricant is about 1 to about 30 percent by weight of the finished lubricant. However, since the base lubricating oils of the present invention have excellent properties, including a low pour point, high VIs, and excellent oxidation stability, a smaller amount of additives may be required to meet the specifications for the finished lubricant than usual required with base oils prepared by other methods. The use of additives in formulating finished lubricants is well documented in the literature and known to those skilled in the art.

Examples The invention is further illustrated by the following illustrative, non-limiting examples.

All simulated distillation boiling range distributions in this specification, unless otherwise stated, are measured using the standard analytical method D 6352-98 or the equivalent thereof. As used herein, an analytical method equivalent to D 6352-98 refers to any analytical method that gives essentially the same results as the standard method.

Example 1 Example 1 gave a base lubricating oil prepared from an n-C28 feed (purchased from Aldrich) using a Pt / SSZ-32 catalyst (0.3 wt% Pt) bound with 35 wt. % Catapal alumina. The test took place at 1000 psig, 0.8 LHSV and a one-time throughput of H2 of 7 MSCF / bbl. The reactor temperature was 575 ° F. The effluent from the reactor was then passed over a Pt-25 Pd / SiO 2 -Al 2 O 3 hydrofinish catalyst at 450 ° F and, in addition to the temperature, the same conditions were applied as in the isomerization reactor. The yield of 600 ° F + product was 71.5% by weight. The conversion of the wax into material in the boiling range of 600 ° F was 28.5% by weight. The conversion below 700 ° F was 33.6% by weight. The bottom fraction of the test (75.2 wt%) was fractionated at 743 ° F to give 89.2 wt% of bottom product (67.1 wt% of the entire feed). The properties of the hydroisomerized oil bottoms product are shown in Table I below: 1027242 "34

Table I.

Properties of the hydroisomerized oil bottom product Pour point, ° C +3 NMR analysis C2 branch 0.26 C3 branch 0.2 C4 branch 0.26 C5 + branch 0.97

Inner ethyl 0.09

Sum 1.78 NMR branching properties Alkyl branching properties / molecule 1.78

Alkyl branches / 100 carbon atoms 6.14

Percentage branching in two-place 14.6

Percentage of branching in two plus three 25.8 places

Percentage of branching in the five or 54.5 higher places

These bottoms were then subjected to solvent dewaxing at -15 ° C, with 84.2% by weight of solvent dewaxed oil (56.5% by weight of the entire feed) and 15.7% by weight were obtained. Evaluations of the properties of the oil are shown in Table VI below.

Example 2 An n-C36 feed (purchased from Aldrich) was isomerized over a Pt / SSZ-32 catalyst containing 0.3% Pt and 35% Catapal alumina binder. The test conditions were 580 ° F, 1.0 LHSV, reactor pressure 1000 psig and a one-time throughput of hydrogen with a flow rate of 7 MSCF / bbl. The effluent from the reactor went directly to a second reactor, also at 1000 psig, which contained a Pt / Pd on silica-aluminum-hydroxide-hydrofinish catalyst. The conditions in that reactor were a temperature of 450 ° F and an LHSV of 1.0. Conversion and yields were as shown in Table II below:

Table II

Conversion <650 ° F, wt% 32.2

Conversion <700 ° F, weight% 34.4

Yields,% by weight of C1-C2 [M5 C3-C4] C5-180 ° F 6 ^ 22 180-350 ° F 7 ~ 4Ö 350-650 ° F 13 ^ 23 650 ° F + 68.09 5 The bottom fraction of the test was isolated. The properties of the hydroisomerized oil bottom fraction are shown below in Table::

Table III

Properties of the hydro isomerized bottom fraction of the stripper Sim. Dist., LV%, ° F

fiP / 5 677/747 1Ö / 3Ö 801/904 50 914 70/90 920/925 95 / FBP 927/929

Pour point, ° C +20

The bottom product of the stripper was subjected to solvent dewaxing at -15 ° C using methyl ethyl ketone (MEK) / toluene. The wax content was 31.5% by weight and the oil yield was 68.2% by weight. The yield of 650 ° F + oil subjected to solvent dewaxing, based on feeding to the process, was 45.4% by weight. Evaluations of the properties of the oil are shown in Table VI below.

1 027242 "* 36

Example 3

A Fischer-Tropsch wax subjected to hydrotreatment was isomerized over a Pt / SSZ-32 catalyst containing 0.3% Pt and 35% Catapal alumina binder. The conditions of the test were 560 ° F, 1.0 LHSV, a reactor pressure of 300 psig and a one-time throughput of hydrogen with a flow rate of 6 MSCF / bbl. The effluent from the reactor was fed directly to a second reactor, also at 300 psig, which contained a Pt / Pd on silica-alumina hydrofinish catalyst. The conditions in that reactor were a temperature of 450 ° F and an LHSV of 1.0. The properties of the Fischer-Tropsch wax subjected to a hydrotreatment are shown in Table IV below. The conversion and yields, as well as the properties of the hydroisomerized bottoms product of the stripper are shown in Table V below.

Table IV

Inspections of Fischer-Tropsch wax subjected to hydrotreatment (951-15-431)

Specific weight, API 40.3

Nitrogen, ppm 1.6

Total sulfur, ppm 2

Sim. Dist., Wt%, ° F

BP / 5 512/591 10/30 637/708 50 764 70/90 827/911 95 / FBP 941/1047 1027242 ** 37

Table V

Isomerization of FT wax over Pt / SSZ-32 at 560 ° F, 1 LHSV, 300 psig and 6 MSCF / bbl H2

Conversion <650 ° F,% by weight __ 15.9

Conversion <700 ° F,% by weight - 14.1

Yields,% by weight

Bottom product from the stripper: ___

Yield,% by weight of food__75.9_

Sim. Dist, LV%, ° F

IBP / 5_ 588 / 662_ 30 / 50_ 779 / 838_95 / 99__1070 / 1142_

Pour point, ° C__j25_ NMR analysis: __ _C2 branching__0.28_ C3 branching__0.23_ C4 branching__0j26_ _C5f-branching ___ 1.00_ _Individed ethyl__0.11 \ _Sum__1.88_ NMR branching properties: ___Alkylinks8 carbonyl8.8 , 21_ _Percentage branching in the two-place__14.9 _ _Percentage branching in the two-plus three-places 27.1_

Percentage of branching in the five or higher places 53.2 _1027242 1.5 38

The bottom product of the stripper was subjected to solvent dewaxing at -15 ° C using MEK / toluene. The wax content was 33.9% by weight and the oil yield was 65.7% by weight. The yield of 650 ° F + oil subjected to solvent dewaxing, based on feeding to the process, was 49.9% by weight. Evaluations of the properties of the oil are shown in Table VI below.

Table VI

Properties of hydroisomerized wax after solvent dewaxing

Example 1 Example 2 Example 3 NMR analysis C2 branch 0.24 0.27 0.27 C3 branch 0.14 0.12 0.18 C4 branch 0.18 0.23 0.21 C5 + branch 1, 12 1.75 1.1

Inner ethyl 0.07 0.13 0.1

Sum 1.75 2.60 1.86

Branching Index (CI) 19.7 18.8 19

Branching Proximity (BP) 28.5 29.6 28.1

Alkyl branches per molecule 1.68 2.47 1.76 B1-0.5BP 5A5 4

Free carbon index (FCI) 7.90 11.00 7.70

Alkyl branches per 100 carbon-6.04 6.66 6.42 atoms

Percentage branching in the 2nd place 13.7 10.4 14.5

Percentage of branching in the 2 + 3- 21.7 18.8 24.2 places

Percentage of branches in the 5 or 64.0 67.3 59.1 higher places

Viscosity index 165 182 175

Viscosity at 100 ° C 3,447 5,488 3,776

Viscosity at 40 ° C 12.43 23.62 13.90 1027242 * 39

Pour point, ° C ΓΪ5 Π0 ΓΪ8

Cloud point, ° C -4 -3 -5

Average carbon number 27.8 37.1 27.4

Sim. Dist., LV%, ° F

ffiP / 5 683/748 608/652 10/30 792/902 670/718 50 912 775 70/90 919/923 890/953 95 / FBP 924/926 1004/1116 FIMS analysis% paraffins 100 98 96% mononaphthenes 0 1.7 4% dinaphthenes 0 0 0% triphthenes 0 0 0% tetranaphthenes 0 0 0% pentanaphthenes 0 0 0% hexanaphthenes 0 0 0

Total 100 99.7 100

Oxidator BN, hour 31.87

Various modifications and changes to this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. Other objects and advantages will become apparent to those skilled in the art after considering the foregoing description.

1027242 *

Claims (30)

A base lubricating oil comprising paraffinic hydrocarbon components wherein the degree of branching is less than 8 alkyl branches per 10 carbon atoms and 5 wherein less than 20% by weight of the alkyl branches are in the 2-position; the basic lubricating oil has a pour point lower than -8 ° C; a kinematic viscosity at 100 ° C of about 3.2 cSt or higher; and a viscosity index higher than a target viscosity index, as calculated according to the following equation: Intended viscosity index = 22 x ln (kinematic viscosity at 100 ° C) +132. A base molar oil according to claim 1, wherein the base lubricating oil comprises paraffinic hydrocarbon components wherein the degree of branching is less than 7 alkyl branches per 100 carbon atoms. 15 The base lubricating oil according to claim 1 or 2, wherein the base lubricating oil comprises paraffinic hydrocarbon components wherein the degree of branching is less than 6.5 alkyl branches per 100 carbon atoms. The basic lubricating oil according to any of claims 1-3, wherein the basic lubricating oil comprises paraffinic hydrocarbon components in which less than 25% by weight of the alkyl branches are in the two plus three positions. 5. Basic lubricating oil according to any of claims 1-4, wherein the basic lubricating oil comprises paraffinic hydrocarbon components in which more than 50% by weight of the alkyl branches are in the five or higher positions. A base lubricating oil according to any one of Claims 1-5, wherein the viscosity index is higher than the intended viscosity index plus five. 30 The basic lubricating oil according to any of claims 1-6, wherein the basic lubricating oil comprises paraffinic hydrocarbon components in which less than 15% by weight of the alkyl branches are in the second position. i 2 2 2 2 2 The base lubricating oil of any one of claims 1-7, wherein the base lubricating oil comprises paraffinic hydrocarbon components in which less than 20% by weight of the alkyl branches are in the two-plus-three positions. 5 The base lubricating oil according to any of claims 1-8, wherein the base lubricating oil comprises paraffinic hydrocarbon components in which more than 60% by weight of the alkyl branches are in the five or higher locations. The base lubricating oil of any one of claims 1-9, further comprising a total naphthen content of less than about 5% by weight. The basic lubricating oil according to any of claims 1 to 10, wherein the basic lubricating oil is obtained via a Fischer-Tropsch synthesis process. 15 The base lubricating oil of any one of claims 1 to 11, wherein the base lubricating oil comprises paraffinic hydrocarbon components wherein the degree of branching, as measured by the percentage of methyl carbon atoms (B1), and the proximity of branching, as measured by the percentage of repeating methylene 20 carbon atoms that are four or more carbon atoms removed from an end group or branch (CH 2> 4), such that B 1 - 0.5 (CH 2> 4) <12. 13. Basic lubricating oil according to any of claims 1-12, wherein the basic lubricating oil comprises paraffinic hydrocarbon components in which the degree of branching, as measured by the percentage of methyl carbon atoms (B1), and the proximity of branching, as measured by the percentage of repeating methylene - carbon atoms that are four or more carbon atoms removed from an end group or branch (CH2> 4), such that B1 - 0.5 (CH2> 4) <10. The base lubricating oil of any one of claims 1-13, wherein the base lubricating oil has a free carbon index higher than about 3. 1 0 2 7 242______ The base lubricating oil of claim 11, wherein the base lubricating oil comprises a sulfur content of less than about 5 ppm. A base lubricating oil according to any one of claims 1-15, wherein the base lubricating oil 5 has an oxidizer BN value longer than 25 hours. 17. Basic lubricating oil according to any one of claims 1 - 16, further comprising an additional basic oil selected from the group consisting of usual group I base oils, usual group II base oils, common group III base oils, isomerized petroleum wax, polypropylene alpha-olefins, poly-internal-olefins, di-esters, polyol esters, phosphate esters, alkylated aromatics and mixtures thereof. 18. A base lubricating oil comprising paraffinic hydrocarbon components according to any one of claims 1-17, wherein the degree of branching is less than 2.5 alkyl branches per molecule. A base lubricating oil comprising paraffinic hydrocarbon components according to any one of claims 1-17, wherein the degree of branching is less than 2.0 alkyl branches per molecule. 20 A base lubricating oil comprising paraffinic hydrocarbon components according to any one of claims 1 to 17, wherein the base lubricating oil has a pour point lower than -9 ° C. 21. Basic lubricating oil comprising paraffmic hydrocarbon components according to any one of claims 1-17, wherein the basic lubricating oil has a pour point <-15 ° C. A basic lubricating oil comprising a pour point lower than -8 ° C; a kinematic viscosity at 100 ° C higher than 3.2 cSt; and a viscosity index higher than a target viscosity index, as calculated from the following equation: Intended viscosity index = 22 x ln (kinemetic viscosity at 100 ° C) + 132. 1027242 The basic lubricating oil according to claim 22, wherein the basic lubricating oil has a pour point lower than -9 ° C. 24. Basic lubricating oil according to claim 22 or 23, wherein the basic lubricating oil has a pour point lower than -15 ° C. A ready lubricant comprising: the base lubricating oil according to any one of claims 1 to 17; and one or more lubricant additives. 10 The ready lubricant of claim 25, further comprising an additional base oil selected from the group consisting of conventional group I base oils, conventional group Π basic oils, common III group base oils, isomerized petroleum wax, poly-alpha olefins, poly-internal olefins, di-esters, polyol esters, phosphate esters, alkylated aromatics and mixtures thereof. A ready lubricant comprising the basic lubricating oil according to any one of claims 22 to 24; and one or more lubricant additives. 20 The ready lubricant of claim 27, further comprising an additional base oil selected from the group consisting of conventional Group I base oils, conventional Group II base oils, conventional Group III base oils, isomerized petroleum wax, poly-alpha olefins, poly-internal olefins, di-esters, polyol esters, phosphate esters, alkylated aromatics and mixtures thereof. 29. An oil isomerate intermediate comprising paraffinic hydrocarbon components obtained via Fischer-Tropsch, the degree of branching being less than 7 alkyl branches per 100 carbon atoms. 30 The oil isomerate intermediate of claim 29, wherein the oil isomerate intermediate comprises paraffinic hydrocarbon components wherein the degree of branching is less than 6.5 alkyl branches per 100 carbon atoms. 1 0 2 7 2 4 2