JP2007508441A - Lubricant base oil with optimized branching - Google Patents

Abstract

  The present invention relates to a lubricant base oil comprising a paraffinic hydrocarbon component having optimized branching. These lubricant base oils, including paraffinic hydrocarbon components with optimized branching, have an overall lower amount of branching, with the branching concentrated towards the center of the lubricant base oil molecule. Have. The present invention also relates to a process for producing these lubricant base oils from a waxy feedstock and to commercial finish lubricants containing these lubricant base oils.

Description

  The present invention relates to a lubricant base oil comprising a paraffin component having optimized branching. A lubricant base oil comprising a paraffin component with optimized branches has a low amount of branching, with the branches concentrated toward the center of the lubricant base oil molecule. A lubricant base oil comprising a paraffin component with optimized branching has a low pour point and a very high viscosity index. The present invention further relates to a process for producing a lubricant base oil comprising a paraffin component having optimized branching from a waxy feed. The lubricant base oil is useful in commercial finish lubricants.

  Since paraffins have a high viscosity index, high quality lubricants should be paraffinic in type and are generally paraffinic. However, straight chain paraffins in particular are waxy in character and contribute to the high pour point in the oil. Thus, the waxy paraffin feed can be converted to a lubricant base oil by hydroisomerization dewaxing which branches into paraffin molecules. Hydroisomerization dewax typically produces a lubricant base oil with relatively high branching. Although branching on waxy paraffin molecules generally lowers the pour point, it also reduces the viscosity index (VI). A high amount of branching is required for all hydroisomerization processes in order to reach the desired pour point and cloud point. Thus, the product resulting from the hydroisomerization process typically has a viscosity index that is lower than the optimum viscosity index due to the relatively high amount of branching. The lubricant base oil product produced by the hydroisomerization process is similar to the product described in US Pat. Nos. 6,096,940, 6,90,989 and 6,059,955. Branching properties.

  A low pour point is desirable in lubricant base oils. A low pour point indicates that the lubricant base oil will flow and lubricate at low temperatures. The pour point is a measurement of the temperature at which the sample begins to flow under carefully controlled conditions. The pour point can be measured as described in ASTM D5950. Many commercial lubricant base oils have specifications for pour points. If the lubricant base oils have a low pour point, they will also have other good low temperature properties such as low cloud point, low cold filter plugging point and low temperature cranking viscosity. Seem.

  Lubricant base oils having a pour-cloud point spread below about 30 ° C are also desirable. A higher pour-cloud point width requires that the lubricant base oil be processed to a very low pour point in order to satisfy the cloud point specification.

  It is further desirable to have a lubricant base oil that has a high viscosity index. Viscosity index (VI) is an empirical unitless number that shows the effect of temperature change on the kinematic viscosity of the oil. Liquids change viscosity with temperature and become lower when heated; the higher the VI of the oil, the lower its tendency to change viscosity with temperature. High VI lubricants are needed whenever a relatively constant viscosity is required at widely varying temperatures. For example, in automobiles, engine oil must flow freely enough to allow a cold start, but after warming, it must be sufficiently viscous to provide sufficient lubrication. VI can be determined as described in ASTM D2270-93.

  The pour point and VI can be related to the branching of the lubricant base oil onto the paraffinic hydrocarbon molecules. By branching on linear paraffinic hydrocarbons, the pour point is generally lowered and the viscosity index (VI) is lowered. VI tends to decrease sharply when doubling the number of substituents of equal length, but the pour point may be less affected. The API Project 42 data (a study completed from July 1, 1943 to July 1, 1946 by the American Petroleum Institute Research Project 42 at the University of Pennsylvania) shows butyl, phenyl and cyclohexyl content on linear paraffins. For the branches, it was shown that the VI dropped as the branches moved to the middle of the molecule.

  Waxy hydrocarbons prepared from the Fischer-Tropsch process are good potential feedstocks for preparing high quality lubricants. Preferably, the Fischer-Tropsch product contains little, if any, typical petroleum pollutants such as aromatics, sulfur compounds and nitrogen compounds. However, the first Fischer-Tropsch waxy paraffins are generally linear waxes. Thus, the Fischer-Tropsch product needs to be subjected to processing or to improve performance to provide a high quality lubricant base stock.

  Many investigators have been investigating ways to convert waxy feeds, particularly waxy feeds from Fischer-Tropsch synthesis processes, to lubricant base stocks. For example, a catalyst (eg, beta zeolite) in an attempt to create a branch that is sufficient to lower the pour point, but not excessively branched to significantly reduce VI. The combination used was hydroisomerization with solvent dewaxing. Nevertheless, considerable branching is still produced in the prior art methods using this technique.

For example, US Pat. No. 6,090,989 discloses a hydrodewaxing process for making a lubricant base stock. The lubricant base oil base stock as disclosed in that patent is the degree of branching (BI) as measured by the percentage of methyl hydrogen, and four or more carbons or branches away from the end groups. , Branch proximity as measured by the percentage of repeat methylene carbon (CH ₂ > 4) is (a) BI−0.5 (CH ₂ > 4) greater than 15, and (b) BI + 0. Contains a paraffinic hydrocarbon component that is such that 85 (CH ₂ > 4) <45. This calculation means that for a molecule containing 24 carbons, the molecule has at least 2.5 branches per molecule, or there are more than about 9 branches for every 100 carbons. .

  US Pat. No. 6,008,164 discloses a method for producing a lubricant base stock from Fischer-Tropsch wax, wherein the lubricant base stock has a preselected oxidative stability. A lubricant base oil is a mixture of branched paraffins wherein the branched paraffin contains no more than 4 alkyl branches and the free carbon index (FCI) of the branched paraffin is at least about 3. It is disclosed as containing. The examples in US Pat. No. 6,008,164 show lubricant base oils having 3.46, 3.14, 4.19 and 3.59 branches per molecule.

  WO 99/45085 discloses an integrated method for preparing a lubricating oil base stock that includes an isomerization step and a subsequent solvent dewaxing step. In that process, a waxy feed, as disclosed in the international publication, is isomerized to an intermediate pour point on a selected molecular sieve and the isomerized oil is then solvent dewaxed. The The resulting lubricant base stock is disclosed as having a viscosity index greater than about 140. The example of the above-mentioned '085 International Publication shows a lubricating oil base material having a viscosity index greater than 140, which is 156 at the highest.

  EP 0 769 959 A2 contacts a Fischer-Tropsch wax feed with a hydroconversion catalyst under hydroconversion conditions; the resulting hydroconversion effluent is at least one light fraction and a heavy fraction. And a method for preparing a lubricant base oil having a VI of at least 150 from a Fischer-Tropsch wax feed comprising dewaxing the heavy fraction to produce a base oil. ing. The feed to the process is narrowly limited to Fischer-Tropsch wax with a freezing point of at least 50 ° C., and the difference between 90 wt% boiling point and 10 wt% boiling point is in the range of 40-150 ° C. Has boiling range. The hydroconversion catalyst is disclosed as an amorphous catalyst.

US Pat. No. 6,096,940 discloses a method for producing a biodegradable hydrocarbon lubricant base oil. The method involves the weight of 700 ° F. + feedstock converted to 700 ° F.-material on a bifunctional non-noble metal group VIII metal catalyst by contacting the 700 ° F. + Fischer-Tropsch wax feed with hydrogen. The hydroisomerization and hydrocracking reactions occur at 700 ° F. + conversion level ranging from about 20 to about 50 percent on a single pass basis to produce a C ₅ -1050 ° F. crude fraction. Isoparaffins contained in the crude fraction are disclosed as having methyl branches in an amount of less than about 7.5 methyl branches per 100 carbons. From C _5-1050 ° F fraction, the residual fraction is recovered having an initial boiling point in the range of about 650 ° F. to about 750 ° F. The residual fraction is dewaxed and the dewaxed oil is recovered. A biodegradable hydrocarbon base oil is recovered from the dewaxed oil. In the examples, the recovered lubricant base oil VIs are 130 and 140.

  U.S. Pat. No. 5,059,299 discloses 1) wax on the isomerization catalyst so that about 15-30% of the unconverted wax remains in the oil fraction of the isomerate boiling in the lubricating oil boiling range. Isomerize, 2) fractionate the product, and 3) boil at a flow below 9 ° C / filter delta T (temperature difference between the dewaxed oil pour point and the filtration temperature) in the lubrication boiling range. The process of solvent dewaxing the fraction and 4) recovering the dewaxed lube oil product maximizes the yield of a lube base stock having a pour point of less than about -21 ° C. and a viscosity index of greater than about 130. A method is disclosed. Suitable dewaxing catalysts for use in this invention are widely defined and include catalysts such as fluorinated alumina.

  We have also entered research into how to analyze the composition of lubricant base oils and how the composition affects the properties of lubricant base oils. For example, "Effect of Group II & III base oil composition on VI and oxidative stability" prepared for submission at the 1999 AIChE Spring American Meeting in Houston on March 16, 1999 Kramer, D .; C. Et al. Teach that field ionization mass spectrometry (FIMS) is particularly useful in measuring the distribution of paraffins and naphthenes in Group II and III base oils. With aromatics below 1%, the authors found that the most effective way to further improve oxidative stability was to increase VI. In general, the authors have found that the lower the concentration of polycyclic naphthenes in the oil, the higher its VI and oxidative stability.

  There remains a need for an effective and economical method for converting waxy paraffin feedstocks to high quality lubricant base oils, particularly lubricant base oils having good low temperature properties and high viscosity indices. Is in a state.

SUMMARY OF THE INVENTION The present invention is a lubricant group comprising a paraffinic hydrocarbon component having a degree of branching of less than 8 alkyl branches per 100 carbons and having less than 20% by weight alkyl branching at 2 positions. Regarding oil. The lubricant base oil has a pour point of less than −8 ° C .; a kinematic viscosity at 100 ° C. of about 3.2 cSt or more; and the following equation:
Target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132
Having a viscosity index greater than the target viscosity index as calculated by

In other aspects, the invention provides a pour point of less than −8 ° C., a kinematic viscosity at 100 ° C. greater than 3.2 cSt; and the following equation:
Target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132
Relates to a lubricant base oil having a viscosity index greater than the target viscosity index as calculated by.

  In yet another aspect thereof, the present invention relates to a finishing lubricant. The finishing lubricant includes the lubricant base oil as described herein and one or more lubricant additives.

  In another aspect, the present invention relates to an intermediate oil isomerate. The intermediate oil isomerate comprises a Fischer-Tropsch derived paraffinic hydrocarbon component that is less than 7 alkyl branches per 100 carbons.

Detailed Description of Exemplary Embodiments The present invention relates to a lubricant base oil wherein the mixture of paraffinic hydrocarbon components comprises a mixture of paraffinic hydrocarbon components having optimized branches. These lubricant base oils, including mixtures of paraffinic hydrocarbons with optimized branches, have an overall low amount of branches that are concentrated in the center of the lubricant base oil molecule. . The present invention also relates to a process for producing these lubricant base oils from a waxy feedstock and to commercial finish lubricants containing these lubricant base oils.

  In a lubricant base oil having a kinematic viscosity greater than about 3.2 cSt at 100 ° C., the optimized branch has an exceptionally low pour point and a very high viscosity index that is greater than the target viscosity index as defined herein. Can be provided. Optimized branching according to the present invention means that the lubricant base oil molecule consists of paraffinic hydrocarbon components with a generally low amount of branching, with the branching concentrated towards the center of the molecule. To do.

  A lubricant base oil comprising a paraffinic hydrocarbon component having optimized branching and a kinematic viscosity greater than about 3.2 cSt at 100 ° C. is combined with subsequent solvent dewaxing with mild hydroisomerization Can be generated. In accordance with the present invention, the waxy feedstock is subjected to mild hydroisomerization under conditions such that an intermediate oil isomerate consisting of paraffinic hydrocarbon components having specific branching properties is formed. To be processed. Next, the intermediate oil isomerate has optimized branching and conditions for providing a lubricant base oil comprising a paraffinic hydrocarbon component having a kinematic viscosity greater than about 3.2 cSt at 100 ° C. Below is subjected to solvent dewaxing. The method of the present invention provides a lubricant base oil comprising paraffinic hydrocarbons with optimized branching such that there is an overall low amount of branching, with the branching concentrated toward the center of the molecule. Arise. The degree of branching and branching position can be determined by NMR analysis.

  Maximizing branching towards the center of the lubricant base oil while minimizing overall branching can provide a lubricant base oil with a particularly high viscosity index and low pour point. It was surprisingly found. Thus, a high quality lubricant base oil having a particularly high viscosity index and low pour point is produced.

Definitions The following terms are used throughout the specification and have the following meanings unless otherwise stated.
“Derived from a Fischer-Tropsch synthesis or method” means that the fraction, stream or product of interest is derived from a Fischer-Tropsch method or produced in a step by a Fischer-Tropsch method. Means that

A “waxy hydrocarbon feedstock” is a feedstock or stream containing molecules having a C ₂₀₊ carbon number and generally having a boiling point higher than about 600 ° F. (316 ° C.). The waxy hydrocarbon feeds useful in the methods disclosed herein can be synthetic waxy feeds such as Fischer-Tropsch waxy hydrocarbons, or like petroleum waxes It can be derived from natural sources.

  “Lubricant base oil” means a fraction or product that meets the specifications for a lubricant base oil. The lubricant base oil fraction is provided according to the method of the present invention by hydroisomerization / solvent dewaxing and has optimized branching properties. Additional properties of the lubricant base oil provided in accordance with the present invention include an initial boiling point in the range of 600-950 ° F., a final boiling point in the range of 800-1200 ° F., and a range of 3.2-20 cSt at 100 ° C. Viscosity ranges from 158 to 240, preferably from 163 to 220, more preferably from 165 to 200. The lubricant base oil is less than −8 ° C., preferably less than −9 ° C., more preferably ≦ −15 ° C., and even more preferably less than −15 ° C., preferably −8 to −35 ° C. Has a pour point in the range. The lubricant base oil also has a cloud point in the range of +5 to -20 ° C.

  “Hydrocarbon or hydrocarbonaceous” means a compound or substance containing hydrogen and carbon atoms that may also contain heteroatoms such as oxygen, sulfur or nitrogen.

The “Target Viscosity Index” is an empirical number derived from kinematic viscosity and viscosity index. The target viscosity index is calculated by the following equation:
Target viscosity index = 22 × 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 target viscosity index is illustrated in the drawing.

  “Alkyl” means a linear saturated monovalent hydrocarbon group of 1 to 6 carbon atoms or a branched saturated monovalent hydrocarbon group of 3 to 8 carbon atoms. Preferably the alkyl group is methyl. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, and the like.

  The “Free Carbon Index (FCI)” is a measure of the number of carbon atoms in an isoparaffin that is located on at least 5 carbons from the terminal carbon and at least 4 carbons away from the side chain. (Measure).

A lubricant base oil having a kinematic viscosity greater than about 3.2 cSt at 100 ° C. containing a paraffinic hydrocarbon component having certain desired branching properties (optimized branching) has a very high viscosity index and excellent low flow It was surprisingly found to have a spot. The viscosity index of the lubricant base oil of the present invention is greater than the target viscosity index of the oil. Preferably the viscosity index of the lubricant base oil of the present invention is greater than the target viscosity index of the oil plus 5. The target viscosity index as defined above is viscosity dependent and is calculated by the following equation:
Target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132.

  These lubricant base oils consist of a mixture of paraffinic hydrocarbons, with the overall mixture of paraffinic hydrocarbon components having optimized branches. These lubricant base oils containing paraffinic hydrocarbon components with optimized branching are produced from a waxy feed. The present invention also relates to intermediate oil isomerates produced in the process for preparing the lubricant base oils of the present invention. The intermediate oil isomerate of the present invention includes a paraffinic hydrocarbon component having specific branching properties. Thus, when the intermediate oil isomerate is converted to a lubricant base oil, the lubricant base oil includes a paraffinic hydrocarbon component having optimized branching properties. The intermediate oil isomerate is composed of paraffinic hydrocarbons in which the paraffinic hydrocarbon component has an overall low amount of branching.

  The intermediate oil isomerate is converted to a lubricant base oil composed of paraffinic hydrocarbon components having optimized branching properties. Optimization of the branching properties according to the present invention means that the paraffinic hydrocarbon component has an overall low amount of branching, where the branching is concentrated towards the center of the molecule. Thus, branching is minimized towards the end of the molecule.

Branches on the paraffinic hydrocarbon component of the lubricant base oil and the intermediate oil isomerate are alkyl branches. In lubricant base oils and intermediate oil isomerates, the alkyl branches are primarily methyl branches (—CH ₃ ). According to the present invention, branching properties are optimized in the lubricant base oil. Branching properties include the degree of branching and the location of the branch. The degree of branching can be measured by the number of alkyl branches per carbon of a certain number of paraffinic hydrocarbon components. Preferably the degree of branching is measured by the number of alkyl branches per 100 carbons. The position of the branch is measured relative to the end of the paraffin hydrocarbon chain and is one position of the terminal carbon, two positions in the next adjacent carbon, and so on until the center of the hydrocarbon chain is reached. 3 positions, and so on. Positions on the hydrocarbon chain can be exemplified as follows:

  An intermediate oil isomerate is an intermediate product of the process for preparing the lubricant base oil of the present invention. Intermediate oil isomerates are produced by subjecting a waxy feed to a mild hydroisomerization process using a specific class of shape-selective catalysts that provide a large degree of pour point reduction with minimal branching. The The intermediate oil isomerate is solvent dewaxed to provide the lubricant base oil of the present invention.

  According to the present invention, the intermediate oil isomerate comprises a paraffinic hydrocarbon component having specific branching properties. The intermediate oil isomerate is composed of paraffinic hydrocarbon components having an overall low amount of branching. In particular, the intermediate oil isomerate consists of paraffinic hydrocarbon components having less than 7.0 alkyl branches per 100 carbons, preferably less than 6.5 alkyl branches per 100 carbons.

  The intermediate oil isomerate is solvent dewaxed to provide the lubricant base oil of the present invention. In accordance with the present invention, the lubricant base oil includes a paraffinic hydrocarbon component that is optimized for branching. The lubricant base oil is an optimized branch in that the paraffinic hydrocarbon component of the isomerate has an overall low amount of branching concentrated towards the center of the molecule. Including a paraffinic hydrocarbon component.

  In particular, the lubricant base oil has less than 8 alkyl branches per 100 carbons, preferably less than 7 alkyl branches per 100 carbons, more preferably less than 6.5 alkyl branches per 100 carbons. Including a paraffinic hydrocarbon component. The lubricant base oil also includes a paraffinic hydrocarbon component having less than 20% by weight branching at two positions, preferably less than 15% by weight branching at two positions. The lubricant base oil also has a low amount of branching at 2 plus 3 positions, preferably less than 25 wt%, more preferably less than 20 wt%. Furthermore, the lubricant base oil has branches at more than 5 positions, greater than 45% by weight, more preferably greater than 50% by weight.

  Also, a lubricant base oil having a low kinematic viscosity and a low pour point, generally less than about 3.2 cSt at 100 ° C., rather than producing a lubricant base oil having a higher pour point and having a higher kinematic viscosity. It is generally accepted in the art that it is easier to produce. The paraffinic hydrocarbons that make up the low kinematic lubricant base oil are of relatively shorter paraffin chains, typically less than about 25 carbons in length. Since lubricant base oils with relatively low kinematic viscosities are of relatively short paraffin chains, these lubricant base oils generally require fewer branches to reach a low pour point.

  In contrast, higher viscosity lubricant base oils contain longer chain length paraffinic hydrocarbon molecules. In these longer paraffinic hydrocarbon molecules of the higher viscosity lubricant base oil, it is even more difficult to isomerize to a lower amount of branching and obtain a lower pour point.

  Also, for butyl, phenyl and cyclohexyl branches, it was shown ahead that VI decreased as the branches moved towards the center of the linear paraffin. Therefore, it would not have been considered desirable to produce a lubricant base oil having a branching configuration towards the center of the paraffin molecule, and in combination with its low amount of branching, it was made exceptionally It is quite surprising to provide a lubricant base oil having a high VI and a low pour point.

In accordance with the method of the present invention, the waxy feed is treated in such a way as to achieve this desired amount of branching and branch placement (ie, optimized branching). Therefore, a lubricant base oil with high viscosity, low pour point and exceptionally high VI is produced. The lubricant base oil of the present invention has a kinematic viscosity at 100 ° C. of greater than about 3.2 cSt, preferably from about 3.2 cSt to about 20 cSt. Also, the lubricant base oil of the present invention comprises an average carbon number greater than about 27, preferably greater than about 30, more preferably greater than about 27 and less than about 70.
The degree of branching and the position of branching can be determined by NMR analysis.

NMR Branching Analysis The branching properties of the lubricant base oils and intermediate oil isomerates of the present invention are determined by analyzing oil samples using carbon-13 NMR according to the following 8-step method. References cited in the description of the process provide details of the process steps. Steps 1 and 2 are performed only for the starting material from the new method.

1. ) Confirm and identify CH branch center and CH ₃ branch end point using DEPT pulse sequence (Pulse sequence) (Doddrell, DT; DT Pegg; MR Bendall) Journal of Magnetic. Resonance) (1982) 48, 323ff).

  2. ) Confirm the absence of multi-branch-initiating carbon (quaternary carbons) using an APT pulse sequence (Patt, S.L .; J.N. Schoolery), Journal of Magnetic Resonance ( 1982) 46, 535ff).

3. Tables and calculated values are used to assign various branch carbon resonances to specific branch positions and lengths (Lindeman, LP, Journal of Qualitative Analytical Chemistry 43 (1971) 1245ff; Netzel, D A. et al., Fuel 60, (1981) 307ff).
(Table 1)
Example:
Branched NMR chemical shift (ppm)
2-Methyl 22.5
3-methyl 19.1 or 11.
4-methyl 14.0
4 + methyl 19.6
Internal ethyl 10.8
Propyl 14.4
Neighboring methyl 16.7

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

For the unique case of 2-methyl branches where both the terminal methyl and the branched methyl appear at the same resonance position, the intensity is divided by 2 before calculating the frequency of branch appearance.
When calculating and tabulating the 4-methyl branch fraction, its contribution to 4 + methyl must be subtracted to avoid double counting.

5). ) Calculate the free carbon index using the calculated average carbon number of the sample and the results from the C-13 NMR analysis as described in EP 1062305. The free carbon index (FCI) is a measurement of the number of carbon atoms in isoparaffins located at least 5 carbons from the terminal carbon and 4 carbons that are separated from the side chain. The average carbon number can be measured with sufficient accuracy for the lubricant material by dividing the molecular weight of the sample by 14 (the formula weight of CH ₂ ). Molecular weight can be measured by ASTM D2502, ASTM D2503 or other suitable methods. In accordance with the present invention, molecular weight is preferably measured according to ASTM D2503-02.

  6). The branching index (BI) and branching proximity (BP) are calculated using the calculations described in US Pat. No. 6,090,989. The branching index is the ratio, in percent, of non-benzylmethyl hydrogen in the range of 0.5 to 1.05 ppm to total non-benzyl aliphatic hydrogen in the range of 0.5 to 2.1 ppm. Branch proximity is% equivalent repeating methylene carbon (epsilon carbon) that is 5 or more removed from the end group or branch.

7). The number of alkyl branches per molecule is the total number of 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) x 100 / number of carbons per molecule.

Measurements can be made using any Fourier transform NMR spectrometer. Preferably, the measurement is performed using a spectrophotometer having a magnet of 7.0 T or more. In all cases, after confirming the absence of aromatic carbon by mass spectrometry, UV or NMR investigation, the spectral width was limited to about 0-80 ppm saturated carbon region versus TMS (tetramethylsilane). A 15-25 wt% solution in chloroform dl form was excited by a 45 ^O pulse, followed by an acquisition time of 0.8 seconds. To minimize non-uniform data, the proton decoupler was disconnected during the 10 second delay before the excitation pulse and connected during acquisition. Total experiment time ranged from 11 to 80 minutes. DEPT and APT sequences could be performed according to the literature description with small deviations described in the Varian or Bruker operating manual.

DEPT is a distortionless enhancement by polarization transfer. DEPT does not indicate a quaternary class. The DEPT45 sequence provides a signal for all carbons attached to protons. DEPT90 shows only CH carbon. DEPT 135 indicates CH and CH ₃ upward and CH ₂ (downward) with a phase difference of 180 degrees. APT is a bound proton test. It allows all the carbon to be observed, but if CH and CH ₃ are up, then the quaternary and CH ₂ are down. The sequence is useful in that every branched methyl should have a corresponding CH. Multiple methyls are clearly identified and confirmed by chemical shifts and phases. Both are described in the cited references.

  Using the assumption in the calculation that the entire sample of lubricant base oil or intermediate oil isomerate was isoparaffin, the branching properties of each sample were determined by C-13 NMR. No correction was made for n-paraffins or naphthenes that may have been present in the oil sample in varying amounts. The% total naphthenes in lubricant base oils were generally low or absent due to the mild hydroisomerization-dewaxing process used in the preparation. Naphthenes content can be measured using Field Ionization Mass Spectroscopy (FIMS).

Feedstock According to the present invention, the feedstock to the process for producing a lubricant base oil with optimized branching is a waxy hydrocarbon feedstock. Waxy hydrocarbon feeds useful in the methods disclosed herein can be synthetic waxy feeds such as Fischer-Tropsch waxy hydrocarbons or are derived from natural sources such as petroleum waxes. be able to. Thus, the waxy feed to the process is Fischer-Tropsch derived waxy feed, petroleum wax, waxy distillate feeds such as gas oils, lubricating oil feeds, high pour point polyalphaolefins, waxes It can consist of foot oil, normal alpha olefin waxes, coarse wax, deoiled waxes, microcrystalline waxes, and mixtures thereof. Preferably, the waxy feed is derived from a Fischer-Tropsch waxy feed. A substantial proportion of the waxy feed consists of molecules having a C ₂₀₊ carbon number and generally has a boiling point greater than about 600 ° F. (316 ° C.). The majority of the molecules in the waxy feed are high molecular weight n-paraffins and slightly branched paraffins that contribute to the waxy nature of the feed.
The waxy hydrocarbon feed can be hydrotreated, if desired, prior to treatment as described herein.

Fischer-Tropsch Synthesis Preferably, the waxy feed of the present invention is derived from a Fischer-Tropsch waxy feed. In Fischer-Tropsch chemistry, synthesis gas is converted to liquid hydrocarbons by contacting the synthesis gas with a Fischer-Tropsch catalyst under reaction conditions. Typically, methane and optionally heavier hydrocarbons (heavier than ethane) are passed through a conventional syngas generator to provide syngas. In general, the synthesis gas contains water and carbon monoxide and may contain small amounts of carbon dioxide and / or water. The presence of sulfur, nitrogen, halogen, selenium, phosphorus and arsenic contaminants in the synthesis gas is undesirable.

  For this reason, and depending on the quality of the synthesis gas, it is preferable to remove sulfur and other contaminants from the feed before performing Fischer-Tropsch chemistry. Means for removing these contaminants are well known to those skilled in the art. For example, ZnO guard beds are preferred for removing sulfur impurities. Means for removing other contaminants are well known to those skilled in the art. It may also be desirable to purify the synthesis gas prior to entering the Fischer-Tropsch reactor to remove the carbon dioxide produced during the synthesis reaction and any additional sulfur compounds that have not yet been removed. This can be done, for example, by contacting the synthesis gas with a gently alkaline solution (eg, aqueous potassium carbonate) in a packed column.

In the Fischer-Tropsch process, when a synthesis gas containing a mixture of H ₂ and CO under suitable temperature and pressure reaction conditions is contacted with a Fischer-Tropsch catalyst, liquid and gaseous hydrocarbons are formed. Fischer-Tropsch reactions are typically conducted at temperatures of about 300-700 ° F. (149-371 ° C.), preferably about 400-550 ° F. (204-228 ° C.); about 10-600 psia (0.7 Pressure of about 30 to 300 psia (2 to 21 bar); and a space velocity of the catalyst of about 100 to 10,000 cc / g / hour, preferably about 300 to 3,000 cc / g / hour. Done in Examples of conditions for conducting Fischer-Tropsch type reactions are well known to those skilled in the art.

The product of the Fischer-Tropsch synthesis process is mostly in the C _{5 to} C ₁₀₀₊ range and can be in the C _{1 to} C ₂₀₀₊ range. The reaction can be carried out in various reactor types, such as a fixed bed reactor containing one or more catalyst beds, a slurry reactor, a fluidized bed reactor or a combination of different types of reactors. . Such reaction methods and reactors are well known and are shown in the literature.

  A preferred slurry-fischer-tropsch process in the practice of the present invention utilizes the excellent heat transfer (mass transfer) properties for a strongly exothermic synthesis reaction, and a relatively high molecular weight when using a cobalt catalyst. Paraffinic hydrocarbons can be produced. In a slurry process, a third phase in a slurry comprising a granular Fischer-Tropsch type hydrocarbon synthesis catalyst dispersed and suspended in a slurry liquid containing a hydrocarbon product of a synthesis reaction that is liquid under reaction conditions. And bubbling a synthesis gas containing a mixture of hydrogen and carbon monoxide. The molar ratio of hydrogen to carbon monoxide can range from about 0.5 to about 4, but more typically from about 0.7 to about 2.75, preferably about 0.7. In the range of ~ 2.5. A particularly preferred Fischer-Tropsch process is taught in EP 06009079 (also fully incorporated herein by reference for all purposes).

  In general, Fischer-Tropsch catalysts contain a Group VIII transition metal on a metal oxide support. The catalyst can also contain noble metal promoter (s) and / or crystalline molecular sieves. Suitable Fischer-Tropsch catalysts include one or more of Fe, Ni, Co, Ru and Re, with cobalt being preferred. Preferred Fischer-Tropsch catalysts are effective amounts of cobalt and one or more Re, Ru, Pt, Fe, Ni, Th, on a suitable inorganic support, preferably a support comprising one or more refractory metal oxides. , Zr, Hf, U, Mg and La. Generally, the amount of cobalt present in the catalyst is from about 1 to about 50% by weight of the total catalyst composition.

The catalyst may _{also, ThO 2, La 2 O 3} , MgO, and basic oxides such as TiO ₂ cocatalyst, cocatalyst, noble metals such as _{ZrO 2 (Pt, Pd, Ru} , Rh, Os, Ir ), Money metals (Cu, Ag, Au) and other transition metals such as Fe, Mn, Ni and Re. Suitable carrier materials include alumina, silica, magnesia and titania or mixtures thereof. A preferred support for the cobalt-containing catalyst comprises titania. Useful catalysts and their preparation are known and illustrated in US Pat. No. 4,568,663, which is intended to be exemplary, but is not limiting with respect to catalyst selection.

Certain catalysts are known to provide chain growth probabilities that are relatively low to moderate, and the reaction product is a relatively high proportion of low molecules (C _2-8 ). Olefins and relatively low proportions of high molecular weight (C ₃₀₊ ) waxes. Certain other catalysts are known to provide relatively high chain growth probabilities, and the reaction products are relatively low proportions of low molecular weight (C _2-8 ) olefins, And relatively high proportions of high molecular weight (C ₃₀₊ ) waxes. Such catalysts are well known to those skilled in the art and can be easily obtained and / or made.

The product from the Fischer-Tropsch process contains mainly paraffins. The products from the Fischer-Tropsch reaction generally include light reaction products and waxy reaction products. Light reaction products (ie, condensate fraction) are hydrocarbons boiling below about 700 ° F. (eg, tail gas or middle distillate fuel), most of the C _{5 to} C ₂₀ range, Includes increasing amounts up to _C30 . The waxy reaction product (ie wax fraction) diminishes with hydrocarbons boiling above about 600 ° F. (eg vacuum gas oil or heavy paraffins), mostly in the C ₂₀₊ range, down to C ₁₀ Including the amount to be.

  Both the light reaction product and the waxy product are substantially paraffinic. Waxy products generally contain greater than 70% by weight linear paraffins, often greater than 80% by weight linear paraffins. Light reaction products include paraffinic products along with a significant proportion of alcohols and olefins. In some cases, light reaction products can contain alcohols and olefins as high as 50% by weight and even higher. It is the waxy reaction product (ie wax fraction) that can be used as feed for the process of the present invention.

Hydroisomerization In accordance with the present invention, the waxy hydrocarbon feed is subjected to hydroisomerization in the hydroisomerization zone to produce an intermediate oil isomerate.

  Hydroisomerization is intended to improve the cold flow properties of lubricant base oils by the selective addition of branches in the molecular structure. Hydroisomerization dewaxing ideally achieves a high conversion level of waxy feed to non-waxy isoparaffins while at the same time minimizing conversion by cracking.

  According to the present invention, hydroisomerization is performed using a molecular sieve of shape selective intermediate pore size. The hydroisomerization catalyst useful in the present invention comprises a shape selective intermediate pore size molecular sieve on a refractory oxide support and optionally a catalytically active metal hydrogenation component. As used herein, the phrase “medium pore size” refers to an effective range of about 4.0 to about 7.1 liters when the porous inorganic oxide is in a calcined form. Means pore opening. The shape selective intermediate pore size molecular sieves used in the practice of the present invention are generally 1-D10-, 11- or 12-ring molecular sieves.

  Preferred molecular sieves of the present invention are 10 (or 11 or 12) tetrahedrally coordinated atoms (T-atoms) joined by oxygen to 10- (or 11- or 12-) ring molecular sieves. 1-D10-ring type having In 1-D-molecular sieves, 10-ring (or larger) pores are parallel to each other and are not in contact with each other. The classification of internal zeolite channels as 1-D, 2-D and 3-D has been described by F. in the NATO ASI series (1984). R. Rodrigues, L. D. Rollman and C.I. In Zeolites Science and Technology edited by Naccache M.M. Described by Rarrer (incorporated herein in its entirety by reference to this classification (see in particular page 75)).

  Preferred shape selective intermediate pore size molecular sieves 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, and SAPO-11 is most preferred. SM-3 is a particularly preferred shape selective mesopore size SAPO having a crystal structure that falls within the crystal structure of the SAPO-11 molecular sieve. The manufacture of SM-3 and its unique properties are described in US Pat. Nos. 4,943,424 and 5,158,665. Preferred and shape-selective mesoporous size molecular sieves used for hydroisomerization are ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, SSZ-32, offretite. ) And ferrilite. SSZ-32 and ZSM-23 are more preferred.

  Preferred mesopore size molecular sieves are characterized by the selected crystallographic free diameter of the channel, the selected crystal size (corresponding to the selected channel length) and the selected acidity. The desired crystallographic free diameter of the molecular sieve channel is about 4.0 to about 7. with a maximum crystallographic free diameter of 7.1 angstroms or less and a minimum crystallographic free diameter of 3.9 angstroms or more. It is in the range of 1 angstrom.

  The preferred maximum crystallographic free diameter is 7.1 angstroms or less and the minimum crystallographic free diameter is 6.0 angstroms or more. Most preferably, the maximum crystallographic free diameter is not more than 6.5 angstroms and the minimum crystallographic free diameter is not less than 4.0 angstroms. Issued by Elsevier, Ch. Baerlocher, W.M. M.M. Meier and D.M. H. Olson published “Atlas of Zeolite Framework Types”, 5th revised edition (2001), pages 10-15 (incorporated herein by reference) to disclose the crystallographic free diameter of molecular sieve channels. Has been.

Particularly preferred intermediate pore size molecular sieves useful in the present methods are described, for example, in US Pat. Nos. 5,135,638 and 5,282,958, the contents of which are hereby incorporated by reference in their entirety. Are incorporated into the document). In US Pat. No. 5,282,958, such mesopore size molecular sieves have a crystal size of about 0.5 microns or less, a minimum diameter of at least about 4.8 mm, and a maximum diameter of about 7.1 mm. Having pores having The catalyst, when placed in a tube reactor, converts at least 50% of hexadecane at 37 ° C. at a pressure of 1200 psig, a hydrogen flow of 160 ml / min and a feed rate of 1 ml / hour. Have sufficient acidity. The catalyst also exhibits isomerization selectivity of 40% or more (isomerization selectivity is used under conditions leading to 96% conversion of linear hexadecane (n-C ₁₆ ) to other species. If you are:
100x (weight% branched of _C 16 in product) / _{(wt% C} wt% branched of _{C 16} + product in the product _13);
To be determined).

  Such particularly preferred molecular sieves are further characterized by pores or channels having a crystallographic free diameter in the range of about 4.0 to about 7.1, preferably in the range of 4.0 to 6.5. Can do. Issued by Elsevier, Ch. Baerlocher, W.M. M.M. Meier, and D.C. H. In the “Atlas of Zeolite Framework Types” by Olson, 5th revised edition (2001), pages 10 to 15 (incorporated herein by reference), the crystallographic free diameter of the molecular sieve channel is It has been announced.

  If the crystallographic free diameter of the molecular sieve channel is unknown, the effective pore size of the molecular sieve can be measured using standard adsorption techniques and known dynamic diameter hydrocarbonaceous compounds. . Breck's Zeolite Molecular Sieves (1974) (especially Chapter 8); Anderson et al. See Catalysis 58, 114 (1979); and U.S. Pat. No. 4,440,871, incorporated herein by reference where appropriate. Standard techniques are used in performing adsorption measurements to measure pore size. It is convenient to consider a particular molecule as excluded (p / po = 0.5; 25 ° C.) if at least 95% of its equilibrium adsorption value on the molecular sieve is not reached in less than about 10 minutes. ). Intermediate pore size molecular sieves will typically accept molecules with kinetic diameters of 5.3 to 6.5 angstroms with little hindrance.

  The hydroisomerization catalyst useful in the present invention optionally comprises a catalytically active metal hydride. The presence of a catalytically active metal hydride leads to product improvement, particularly VI and stability. Typical catalytically active metal hydrides include chromium, molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum and palladium. Metal platinum and palladium are particularly preferred, with platinum being most preferred. When using platinum and / or palladium, the total amount of active hydrogenation metal is typically in the range of 0.1-5% by weight of the total catalyst, usually in the range of 0.1-2% by weight. Does not exceed% by weight.

  The refractory oxide support may be selected from the oxide supports conventionally used for catalysts, including silica, alumina, silica-alumina, magnesia, titania and combinations thereof.

  The conditions for hydroisomerization will be adapted to achieve isomerized oil intermediates with specific branching properties as described above, thus the characteristics of the feedstock used Will depend on. In general, the conditions for hydroisomerization in the present invention are such that the conversion of the wax to a material boiling below about 700 ° F. is maintained below about 35% by weight in producing the intermediate oil isomerate. As calm as possible.

  Mild hydroisomerization conditions are generally achieved by operating at a low temperature of about 390 ° F. to 650 ° F. with LHSV of about 0.5 / hour to about 20 / hour. The pressure is typically 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 increased isomerization selectivity, which results in more isomerization of the feedstock and less decomposition, thus producing increased yields.

  Hydrogen is present in the reaction zone during the hydroisomerization process at a ratio of hydrogen to source of about 0.5-30 MSCF / bbl (1000 standard cubic feet / barrel), preferably about 1 to about 10 MSCF / bbl. To do. Hydrogen can be separated from the product and recycled to the reaction zone.

  These mild hydroisomerization conditions using shape-selective mesopore size molecular sieves are intermediates containing paraffinic hydrocarbon components having specific branching properties, i.e., having an overall low amount of branching. An oil isomerate is produced.

  As described above, the intermediate oil isomerate has less than 7.0, preferably less than 6.5 alkyl branches per 100 carbons as measured by NMR branching analysis.

Solvent Dewaxing In accordance with the present invention, the intermediate oil isomerate is subjected to solvent dewaxing to produce a lubricant base oil comprising a paraffinic hydrocarbon component having optimized branching properties. Therefore, solvent dewaxing produces a lubricant base oil that includes a paraffinic hydrocarbon component having an overall low amount of branching that is concentrated toward the center of the molecule.

  Solvent dewaxing is available from McGraw-Hill Book Company Inc., New York. (1960) William Gruse and Donald Stevens, Chemical Technology of Petroleum, 3rd edition, pages 566-570, the intermediate oil isomers can be converted to methyl ethyl ketone, methyl isobutyl ketone or toluene. Or is used to remove residual wax molecules from the intermediate oil isomerate by precipitating the wax fraction. See also U.S. Pat. Nos. 4,477,333, 3,773,650 and 3,775,288. In the present invention, solvent dewaxing is to recover unconverted wax after hydroisomerization under mild conditions where the conversion of the wax to a boiling material below about 700 ° F. is less than about 35%. And advantageously used after hydroisomerization.

  According to the present invention, solvent dewaxing can be performed by conventional methods well known to those skilled in the art. Solvent dewaxing can be achieved by cooling the intermediate oil isomerate / solvent mixture under controlled conditions for crystallization of paraffin wax present in the following mixture. In such a method, the intermediate oil isomerate and the dewaxing solvent are heated to a temperature at which the wax is dissolved. Next, about 0.5 until a substantial portion of the wax crystallizes and the dewaxed lubricant base oil product reaches a temperature having a selected pour point temperature (eg, -10 ° C to -20 ° C). The heated charge is passed through a cooling zone where cooling takes place at a uniform and slow rate in the range of from 0C to 4.5C / min.

  When the desired dewaxing temperature is reached, the mixture of wax crystals, intermediate oil isomerate and solvent is solid to recover an oil-solvent solution free of wax and a solid wax containing a small proportion of oil. -Subject to liquid separation. Solid-liquid separation techniques that can be used to separate wax crystals from oil-solvent solutions include known solid-liquid separation methods such as gravity sedimentation, centrifugation and filtration. Most commonly in commercial processes, filtration in a rotary vacuum filter followed by solvent washing of the wax cake is used. The solid wax / oil solution obtained after separation of the solid wax is known as a coarse wax.

  The separated oil-solvent solution is subjected to distillation for recovery of the solvent fraction and the dewaxed lubricant base oil product fraction. This method is described in US Pat. No. 5,413,695, the contents of which are hereby incorporated by reference in their entirety.

  Solvents known to be useful as dewaxing solvents include ketones containing 3 to 6 carbon atoms, such as acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), mixtures of ketones, and benzene. And a mixture of ketones with aromatic hydrocarbons including toluene. Halogenated low molecular weight hydrocarbons, including dichloromethane and dichloroethane, and mixtures thereof are also known dewaxing solvents. Solvent dilution of the waxy oil feed maintains the fluidity of the oil to facilitate easy handling, to obtain optimal wax-oil separation, and to obtain optimal dewaxed oil yield. The degree of solvent dilution depends on the particular intermediate oil isomerate feed and solvent used, access to the filtration temperature in the cooling zone, and the desired final ratio of solvent to oil in the separation zone.

  All or a portion of the wax removed in the dewaxing process is recovered and recycled to the hydroisomerization process for use in the process of the present invention and / or for other uses (eg, sales). For use as waxes that can be processed into or sold. When all or part of the recovered wax is recycled, the wax can be subjected to the hydroisomerization process of the present invention alone or mixed with other waxy feeds. Recycling all or a portion of the recovered wax increases the yield of the process.

  After solvent dewaxing, a lubricant base oil comprising a paraffinic hydrocarbon component having optimized branching is provided. By optimized branching is meant that the lubricant base oil contains a paraffinic hydrocarbon component having an overall low amount of branching that is concentrated towards the center of the molecule. A lubricant base oil comprising a paraffinic hydrocarbon component with optimized branching recovered from the process of the present invention has a kinematic viscosity at 100 ° C. of greater than about 3.2 cSt.

  Also, a lubricant base oil comprising a paraffinic hydrocarbon component with optimized branching has a viscosity index that is greater than the target viscosity index as defined above. Preferably the viscosity index of the lubricant base oil of the present invention is greater than the target viscosity index of the oil plus 5. The lubricant base oil also has a pour point of less than -8 ° C, preferably less than -9 ° C, more preferably ≤-15 ° C, and even more preferably less than -15 ° C.

  Generally, the difference in pour point between the pour point of the lubricant base oil and the intermediate oil isomerate prior to solvent dewaxing is greater than about 25 ° F.

Lubricant base oils comprising paraffinic hydrocarbons having hydrofinishing optimization branching, or optionally the intermediate oil isomerate is hydrofinishing to improve product quality and stability (be hydrofinished) that Can do. During the hydrofinishing, the overall LHSV is about 0.25 to 2.0, preferably about 0.5 to 1.0. The hydrogen partial pressure is greater than 200 psia, preferably in the range of about 500 psia to about 2000 psia. The hydrogen recycle rate is typically greater than 50 SCF / Bbl and is preferably 1000-5000 SCF / Bbl. The temperature is in the range of about 300 ° F to about 750 ° F, preferably in the range of 450 ° F to 600 ° F.

  Suitable hydrogen finishing catalysts are noble metals from Group VIIIA (in accordance with the 1975 rules of the International Union of Pure and Applied Chemistry), such as platinum or palladium on alumina or siliceous matrices, And non-sulfided Group VIIIA and Group VIB, such as nickel-molybdenum or nickel-tin on an alumina or siliceous 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 US Pat. Nos. 4,157,294 and 3,904,513. There are non-noble metals (such as nickel-molybdenum and / or tungsten) and at least about 0.5 wt.%, And generally from about 1 to about 15 wt.% Nickel and / or cobalt determined as the corresponding oxide. Noble metal catalysts (such as platinum) contain more than 0.001% metal, preferably 0.1 to 1.0% metal. Combinations of noble metals such as a mixture of platinum and palladium can also be used.

Lubricant base oil with optimized branching The lubricant base oil of the present invention comprises a paraffinic hydrocarbon component with optimized branching. Lubricant base oils containing paraffinic hydrocarbon components with optimized branching have high viscosity, low pour point and exceptionally high VI. The lubricant base oils of the present invention have a kinematic viscosity at 100 ° C. of greater than about 3.2 cSt, preferably from about 3.2 cSt to about 20 cSt. Also, the lubricant base oil of the present invention has a paraffinic hydrocarbon component having an average carbon number of greater than about 27, preferably greater than about 30, more preferably greater than about 27, and less than about 70. including.

  The American Petroleum Institute (API) classified base oils according to the chemical composition of the base oil. As defined by the API, Group III oils have a very high viscosity index (> 9%) with a total sulfur content of less than 300 ppm and a saturated fatty acid content that is greater than or equal to 90%. 120) oil. API Group III oils are also traditionally produced by severe hydrocracking and / or wax isomerization. The lubricant base oils of the present invention are generally classified as API Group III base oils. If they are prepared from a waxy feed having a low total sulfur content, such as a Fischer-Tropsch feed, the lubricant base oil will also have a total sulfur content of less than 300 ppm.

  Lubricant base oils according to the present invention prepared from a Fischer-Tropsch waxy feed generally have a total sulfur content of less than about 5 ppm, a saturated fatty acid content greater than 95%, and 0 to about 8%. Preferably having a total naphthene content of 0 to about 5%. Total sulfur is measured using ultraviolet fluorescence according to ASTM D5453-00.

  In particular, the lubricant base oil has less than 8 alkyl branches per 100 carbons, preferably less than 7 alkyl branches per 100 carbons, more preferably less than 6.5 per 100 carbons. Contains a paraffinic hydrocarbon component having alkyl branches. As measured by NMR branching analysis, branching at the two positions is less than 20% by weight, preferably less than 15% by weight. The branching at the 2 plus 3 position is less than 25% by weight, preferably less than 20% by weight. Branching at 5 or more positions is greater than 50% by weight, preferably greater than 60% by weight. The free carbon index of the lubricant base oils of the present invention is generally greater than about 3, and preferably greater than about 5.

The lubricant base oils of the present invention have a degree of branching (BI) as measured by the percentage of methyl hydrogen and 4 or more carbons or branched methylene carbons (CH ₂ > 4) away from the end groups. ) Branch proximity, as measured by percentage, is such that BI-0.5 (CH ₂ > 4) is less than 12 while maintaining a low pour point. Preferably, the lubricant base oil of the present invention has a branch such that BI-0.5BP is less than 10, more preferably less than 8, even more preferably less than 6, while maintaining a low pour point. .

  The pour point is the temperature at which a sample of lubricant base oil begins to flow under carefully controlled conditions. Where pour point is given herein, it is measured by the standard branching analysis method ASTM D5950-02, unless stated otherwise. The lubricant base oil with optimized branching according to the present invention has an excellent pour point. The pour point of the lubricant base oil is less than −8 ° C., preferably less than −9 ° C., more preferably ≦ −15 ° C., and even more preferably less than −15 ° C.

  The cloud point is measured complementary to the pour point and is expressed as the temperature at which the lubricant base oil sample begins to appear cloudy under careful specific conditions. The cloud point can be measured, for example, according to ASTM D 5773-95. A lubricant base oil with optimized branching according to the present invention has a cloud point below 0 ° C.

  Lubricant base oils containing paraffinic hydrocarbon components with optimized branches have a very high viscosity index and are greater than the target viscosity index of the lubricant base oil, preferably greater than the target viscosity index of the lubricant base oil plus 5. . The range of kinematic viscosities of lubricant base oils with optimized branching can be greater than 3.2 cSt at 100 ° C. and from about 3.2 cSt to about 20 cSt at 100 ° C.

  The% total naphthenes in the lubricant base oil is generally low or absent due to the mild hydroisomerization dewaxing process used in the preparation. In general, when naphthenes are present, the naphthenes are almost exclusively as mononaphthenes. In the lubricant base oil, the total amount of naphthenes present is 0 to about 8% by weight, preferably 0 to about 5% by weight.

  Kramer D., “Effects of Group II & III Base Oil Composition on VI and Oxidation Stability,” prepared for submission at the 1999 AIChE Spring National Meeting in Houston on March 16, 1999. C. Naphthenes are measured using a field ionization mass spectrometry (FIMS) as described in the publications et al. The percent total naphthene content of the lubricant base oils of this invention was determined by FIMS for each sample,% mononaphthenes,% dinaphthenes,% trinaphthenes,% tetranaphthenes,% pentanaphthenes and% hexanaphthenes. It is determined by adopting the sum of classes.

Since the lubricant base oil of the present invention has very low amounts of aromatics and polycyclic naphthenes, the lubricant base oil has excellent oxidative stability. One method for measuring the oxidative stability of lubricant base oils is the Oxidator BN test, as described in US Pat. No. 3,852,207. The Oxidator BN test measures resistance to oxidation by means of a Dornte-type oxygen absorber. Industrial and Engineering Chemistry Vol. 28 (1936), p. W. See Dornte's “Occurrence of White Oils”. Typically, the condition is 340 ° F. and 1 atmosphere of pure oxygen. Results are reported in time to absorb 1000 ml of O ₂ with 100 g of oil. In the Oxydata-BN test, 0.8 ml of catalyst is used per 100 g of oil and the additive package is included in the oil to be tested. The catalyst is a mixture of soluble metal-naphthenates in kerosene that simulates the average metal analysis of the crankcase oil used.

  The metal concentrations in the catalyst are as follows: copper = 6,927 ppm; iron = 4,083 ppm; lead = 80,208 ppm; manganese = 350 ppm; and tin = 3565 ppm. The additive package is 80 mmol zinc bispolypropylenephenyldithiophosphate per 100 g of oil to be tested. Oxidator BN measures the response of a lubricant base oil in a simulated application. A high value for absorbing one liter of oxygen, or a long time, indicates good oxidative stability. For general applications, it is desirable that the lubricant base oil oxdata BN be higher than 7 hours. For the lubricant base oils of the present invention, the oxydata BN value is greater than about 15 hours, preferably greater than about 30 hours.

Blends The lubricant base oils of the present invention can be used alone or conventional Group I base oils, conventional Group II base oils, conventional Group III base oils, isomerized petroleum waxes, polyalphaolefins (PAO), poly internal olefins (PIO), diesters, polyol esters, phosphate esters, alkylated aromatics and mixtures thereof can be blended with an additional base oil. .

  Alkylated aromatics are synthetic lubricants produced from alkylation of aromatics with haloalkanes, alcohols or olefins in the presence of Lewis acid catalysts or Bronsted acid catalysts. A summary of alkylated aromatic lubricants can be found in Ronald L.L. Synthetic Lubricants and High-Performance Functional Fluids (1993), pages 125-144 (incorporated herein), edited by Shubkin. 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 lubricant base oils of the present invention have excellent cold flow properties, high VI and high oxidative stability, they are ideal blending raw materials to improve conventional lubricant base oils. .

  When the lubricant base oil of the present invention is blended with one or more additional lubricant base oils, the additional base oil should be present in an amount less than 95% by weight of the total resulting base oil composition. preferable.

Finish lubricant lubricant base oils are the most important components of finish lubricants, generally accounting for greater than 70% of the finish lubricant. The finishing lubricant includes a lubricant base oil and at least one additive. Finish lubricants can be used in automotive, diesel engines, axles, transmissions and industrial applications. Finishing lubricants must meet standards for their intended application, as defined by the relevant government agency.

  The lubricant base oils of the present invention are useful in commercial finish lubricants. As a result of their superior VI and low temperature properties, the lubricant base oils of the present invention are suitable for formulating finished lubricants intended for many of these applications. Also, the excellent oxidative stability of the lubricant base oils of the present invention makes them useful in finished lubricants for many high temperature applications.

  Additives that can be blended with the lubricant base oils of the present invention to provide a finished lubricant composition include additives that are intended to improve the selective properties of the finished lubricant. Typical additives include, for example, antiwear additives, EP agents, detergents, dispersants, antioxidants, pour point depressants, VI improvers, viscosity modifiers, friction modifiers, demulsifiers. , Antifoaming agent, corrosion inhibitor, rust inhibitor, seal, swelling agent, emulsifier, wetting agent, lubricity improver, metal deactivator, gelling agent, tackifier, bactericidal agent, fluid-loss (fluid- loss) additives, colorants, and the like.

  Other hydrocarbons, such as those described in US Pat. Nos. 5,096,883 and 5,189,012, have a pour point, kinematic viscosity, flash point and toxicity that require a finished lubricant. It can be blended with a lubricant base oil, provided that it has. These other hydrocarbons include base oils that are particularly useful in drilling fluids. For example, US Pat. No. 5,096,883 is a substantially non-toxic that consists essentially of branched chain paraffins, or branched chain paraffins substituted with ester functional groups, or mixtures thereof. Base oils, preferably having from about 18 to about 40 carbon atoms per molecule, more preferably from about 18 to about 32 carbon atoms per molecule.

U.S. Patent No. _5,189,012, a branched chain oligomers synthesized from one or more olefins containing C 2 _{-C 14} chain length, consisting of oligomers having an average molecular weight of 120 to 1,000 It relates to synthetic hydrocarbons selected from the group.

  Typically, the total amount of additives in the finished lubricant will be from about 1 to about 30% by weight of the finished lubricant. However, since the lubricant base oils of the present invention have a low pour point, high VI and excellent oxidative stability, base oils prepared by other methods can be used to meet the specifications for finished lubricants. A lower amount of additive would be required than is typically required. The use of additives in formulating finishing lubricants is well documented in the literature and well known to those skilled in the art.

The invention is further illustrated by the following illustrative examples that are intended to be non-limiting.
All simulated distillation boiling range distributions in this disclosure are measured using the standard analytical method D6352-98 or equivalent method, unless stated otherwise. As used herein, a method equivalent to D6352-98 refers to any analytical method that gives substantially the same results as a standard method.

Example 1
Example 1, using 35 wt% Catapal (Catapal) alumina as combined Pt / SSZ-32 catalyst (0.3 wt% Pt), from (purchased from Aldrich (Aldrich)) _{n-C 28} feed A formed lubricant base oil was produced. The experimental conditions were 1000 psig, 0.8 LHSV and 7 MSCF / bbl single pass H ₂ . The reactor temperature was 575 ° F. The effluent from the reactor was then passed over a Pt—Pd / SiO ₂ —Al ₂ O ₃ hydrofinishing catalyst at 475 ° F. and the same conditions as in the isomerization reactor except for the temperature. used. The yield of 600 ° F. + product was 71.5% by weight. Conversion of the wax to a material in the 600 ° F. boiling range was 28.5% by weight. Conversion below 700 ° F. was 33.6% by weight. The bottom fraction (75.2 wt%) from the experiment was cut at 743 ° F to give 89.2 wt% bottom (67.1 wt% based on total feed). The properties of the hydroisomerized oil bottoms are summarized in Table I below:

  These bottoms were then solvent dewaxed at −15 ° C. to provide 84.2 wt% solvent dewaxed oil (56.5 wt% based on total feed) and 15.7 wt. % Wax was obtained. The evaluation of the oil properties is summarized in Table VI below.

Example 2
The n-C ₃₆ source (purchased from Aldrich) was isomerized over a Pt / SSZ-32 catalyst containing 0.3% Pt and 35% Catapal alumina binder. The experimental conditions were 580 ° F., 1.0 LHSV, 1000 psig reactor pressure and 7 MSCF / bbl single pass hydrogen rate. The reactor effluent was passed directly through a second reactor containing Pt / Pd hydrofinishing catalyst on silica-alumina and at 1000 psig. The conditions in the reactor were 450 ° F. and 1.0 LHSV. Conversion and yield were as summarized in Table II below:

The bottom fraction from the experiment was isolated. The properties of the hydroisomerized oil bottoms are summarized in Table III below:

  The stripper bottoms were solvent dewaxed using methyl ethyl ketone (MEK) / toluene at -15 ° C. The wax content was 31.5% by weight and the oil yield was 68.2% by weight. The solvent dewaxed 650 ° F. + oil yield based on the feedstock to the process was 45.4% by weight. The evaluation of the oil properties is summarized in Table VI below.

Example 3
Hydrotreated Fischer-Tropsch wax was isomerized over a Pt / SSZ-32 catalyst containing 0.3% Pt and 35% Catapal alumina binder. The experimental conditions were 560 ° F., 1.0 LHSV, 300 psig reactor pressure and 6 MSCF / bbl single pass hydrogen rate. The reactor effluent was passed directly through a second reactor containing Pt / Pd hydrogen finishing catalyst on silica-alumina and at 300 psig. The reactor conditions were a temperature of 450 ° F. and a LHSV of 1.0. The properties of the hydrotreated Fischer-Tropsch wax are summarized in Table IV below. The conversion and yield and the properties of the hydroisomerized stripper bottoms are summarized in Table V below.

(Table 5)
Table IV
Inspection of hydrogenated Fischer-Tropsch wax
(951-15-431)
Gravity, API 40.3
Nitrogen, ppm 1.6
Total sulfur, ppm 2

Simulated distillation, wt%, ° F
IBP / 5 512/591
10/30 637/708
50 764
70/90 827/911
95 / FBP 941/1047

(Table 6)
Table V
560 ° F., 1 LHSV, 300 psig and 6 MSCF / bbl H ₂
Isomerization conversion of FT wax over Pt / SSZ-32 at <650 ° F., wt% 15.9
Conversion <700 ° F., weight% 14.1
Yield, wt%
C1-C2 0.11
C3-C4 1.44
C5-180 ° F 1.89
180-290 ° F 2.13
290-650 ° F 21.62
650 ° F + 73.19
Stripper bottoms yield, source charge weight% 75.9
Simulated distillation, LV%, ° F
IBP / 5 588/662
30/50 779/838
95/99 1070/1142
Pour point, ° C +25
NMR analysis C2 branch 0.28
C3 branch 0.23
C4 branch 0.26
C5 + branch 1.00
Internal ethyl 0.11
Total 1.88

(Table 7)
Table V (continued)
NMR branching properties alkyl branching / molecule 1.88
Alkyl branch / 100 carbon 6.21
% Branch at 2 position 14.9
% Branch at position 2 + 3 27.1
% Branching at 5 or more positions 53.2

  The stripper bottom was solvent dewaxed using MEK / toluene at -15 ° C. The wax content was 33.9% by weight and the oil yield was 65.7% by weight. Based on the feed to the process, the yield of solvent dewaxed 650 ° F. + oil was 49.9% by weight. The properties of the oil are summarized in Table VI below:

  Various modifications and alterations of this invention will become 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 upon review of the earlier description.

Equation for target viscosity index: target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132 (where ln (kinematic viscosity at 100 ° C.) is the natural logarithm of kinematic viscosity at 100 ° C.) 2 illustrates a plot of viscosity at 100 ° C. versus viscosity index provided.

Claims (30)

A lubricant base oil comprising a paraffinic hydrocarbon component having a degree of branching of less than 8 alkyl branches per 100 carbons and less than 20% by weight of the alkyl branches in two positions, the lubrication of which The pour point of the base oil below −8 ° C .; the kinematic viscosity at 100 ° C. above about 3.2 cSt; and the following equation:
Target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132
The lubricant base oil having a viscosity index greater than the target viscosity index as calculated by:   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component having a degree of branching of less than 7 alkyl branches per 100 carbons.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component having a degree of branching of less than 6.5 alkyl branches per 100 carbons.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component wherein less than 25% by weight of the alkyl branch is in the 2 plus 3 position.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component that is greater than 50 wt% of the alkyl branch at a position of 5 or more.   The lubricant base oil of claim 1, wherein the viscosity index is greater than the target viscosity index plus 5.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component having less than 15% by weight of the alkyl branches in the 2-position.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon component wherein less than 20 wt% of the alkyl branches are in the 2 plus 3 position.   The lubricant base oil of claim 1, wherein the lubricant base oil comprises a paraffinic hydrocarbon that is greater than 60% by weight of the alkyl branch at a position of 5 or more.   The lubricant base oil of claim 1, further comprising a total naphthene content of less than about 5 wt%.   The lubricant base oil of claim 1, wherein the lubricant base oil is derived from a Fischer-Tropsch synthesis process. The lubricant base oil has a degree of branching (BI) as measured by the percentage of methyl hydrogen and a percentage of repeating methylene carbons (CH ₂ > 4) that are 4 or more carbons away from the end groups or branches. proximity of branching, as measured by (proximity) is such that is _{BI-0.5 (CH 2> 4} ) <12, including paraffinic hydrocarbon components, lubricating base according to claim 1 oil. The lubricant base oil has a degree of branching (BI) as measured by the percentage of methyl hydrogen and a percentage of repeating methylene carbons (CH ₂ > 4) that are 4 or more carbons away from the end groups or branches. proximity of branching (proximity) as measured by, but such that _{BI-0.5 (CH 2> 4} ) <10, including paraffinic hydrocarbon components, lubricating base according to claim 1 oil.   The lubricant base oil of claim 1, wherein the lubricant base oil has a free carbon index greater than about 3.   The lubricant base oil of claim 11, wherein the lubricant base oil comprises a sulfur content of less than about 5 ppm.   The lubricant base oil of claim 1, wherein the lubricant base oil has an Oxidator BN greater than 25 hours.   Conventional Group I base oils, conventional Group II base oils, conventional Group III base oils, isomerized petroleum waxes, polyalphaolefins, polyinternal olefins, diesters, polyol esters, phosphate esters, alkylated fragrances The lubricant base oil of claim 1, further comprising an additional base oil selected from the group consisting of families and mixtures thereof.   The lubricant base oil comprising a paraffinic hydrocarbon component of claim 1 wherein the degree of branching is less than 2.5 alkyl branches per molecule.   The lubricant base oil comprising a paraffinic hydrocarbon component of claim 1 wherein the degree of branching is less than 2.0 alkyl branches per molecule.   The lubricant base oil comprising a paraffinic hydrocarbon component of claim 1, wherein the lubricant base oil has a pour point of less than -9 ° C.   The lubricant base oil comprising a paraffinic hydrocarbon component according to claim 1, wherein the lubricant base oil has a pour point of ≦ −15 ° C. A pour point less than -8 ° C;
A kinematic viscosity at 100 ° C. greater than 3.2 cSt; and the following equation:
Target viscosity index = 22 × ln (kinematic viscosity at 100 ° C.) + 132
A viscosity index greater than the target viscosity index as calculated by
Including lubricant base oil.   The lubricant base oil of claim 22, wherein the lubricant base oil has a pour point of less than −9 ° C.   The lubricant base oil of claim 22, wherein the lubricant base oil has a pour point of less than ≦ −15 ° C. The lubricant base oil of claim 1; and one or more lubricant additives;
Including finishing lubricants.   Conventional Group I base oils, conventional Group II base oils, conventional Group III base oils, isomerized petroleum waxes, polyalphaolefins, polyinternal olefins, diesters, polyol esters, phosphate esters, alkylated fragrances 26. The finishing lubricant of claim 25, further comprising an additional base oil selected from the group consisting of families and mixtures thereof. The lubricant base oil of claim 22; and one or more lubricant additives;
Including finishing lubricants.   Conventional Group I base oils, conventional Group II base oils, conventional Group III base oils, isomerized petroleum waxes, polyalphaolefins, polyinternal olefins, diesters, polyol esters, phosphate esters, alkylated fragrances 28. The finishing lubricant of claim 27, further comprising an additional base oil selected from the group consisting of families and mixtures thereof.   An intermediate oil isomerate comprising a Fischer-Tropsch derived paraffinic hydrocarbon component having a degree of branching of less than 7 alkyl branches per 100 carbons.   30. The intermediate oil isomerate of claim 29, wherein the intermediate oil isomerate comprises a paraffinic hydrocarbon component having a degree of branching of less than 6.5 alkyl branches per 100 carbons.

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