JP2010535925A - Lubricating base oil blend - Google Patents

Abstract

(A) a mineral oil-derived base oil having a saturate content of more than 90% by weight, a sulfur content of less than 0.03% by weight and a viscosity index of 80 to 150; and (b) a viscosity at 100 ° C. of 7 A lubricating base oil blend containing ˜30 cSt (7-30 mm ² / s) paraffinic base oil component, wherein component (b) is a repeat of 4 or more carbons removed from end groups and branches The group consisting of an isomerized Fischer-Tropsch derived bottom product in which the ratio of the percentage of methylene carbon to the percentage of isopropyl carbon atoms (%) is less than 8.2 as determined by ¹³ C-NMR Oil blend.
[Selection] Figure 1

Description

The present invention comprises (a) a mineral oil derived base oil having a saturate content of greater than 90% by weight, a sulfur content of less than 0.03% by weight, and a viscosity index (VI) of 80-150, and (b) The present invention relates to a lubricating base oil blend containing a paraffinic base oil component having a viscosity at 100 ° C. of 7 to 30 cSt (7 to 30 mm ² / s). The invention further relates to a process for producing such a blend.

  There is an increasing demand for many uses of high viscosity lubricating base oils. However, the maximum achievable viscosity of both Group II and Group III base oils is defined by the origin and composition of the crude distillate or slack wax feed used. This is due to the fact that the molecular weight does not increase during manufacture, and thus the maximum molecular weight and thus the associated viscosity cannot be higher than the high molecular weight compounds already present in the raw material. Furthermore, during the hydrotreating process, the molecular weight of the resulting product is constantly reduced by the decomposition reaction, and the structure of the compound is also decomposed. As a result, the severity of hydroprocessing to achieve a desired saturate content of 90% by weight or more means that the maximum viscosity obtained is limited by the cracking and the molecular weight of the raw material, so the applicant It has been found that it is extremely difficult to produce an API Group II base oil having a kinematic viscosity at 100 ° C. exceeding 12 cSt from the derived raw material. It has also been found that this difficulty is further increased in the case of API Group II base oils where a maximum kinematic viscosity at 100 ° C. of 9 or less can be achieved for mineral oil derived feeds. However, the low severity hydroprocessing will not be able to meet the base oil standards and will reduce or impair oxidation stability.

  US-A-70553254 discloses a blend comprising a distillate base oil containing more than 90% by weight of saturates and a residual Fischer-Tropsch derived paraffinic base oil component. Applicant, as disclosed in US-A-70553254, mineral oil derived base oil blends with high kinematic viscosities are obtained by addition of isomerized Fischer-Tropsch bottom products, but impair blend homogeneity Without having found that the amount of Fischer-Tropsch bottom product that can be added is limited, as represented by the high cloud point. As a result, the desired kinematic viscosity at 100 ° C. could not be achieved with a clear and clear blend at ambient temperatures over time. Alternatively, prior to the blends of the present invention, to achieve a suitably high viscosity, rather expensive and difficult to obtain highly viscous poly alpha-olefin (PAO) fluids are used and suitably high at the desired viscosity level. In order to obtain a lubricating base oil having a combination of cloud points, it was necessary to use large amounts of expensive and potentially shear unstable viscosity modifiers.

  Therefore, the object of the present invention is to have a high viscosity index, high saturate content, pour point and cloud point without applying severe hydroprocessing / hydroisomerization process to mineral oil components. It is an object to provide an easily available lubricating base oil composition having a low and high kinematic viscosity. Another object of the present invention is to provide a process for producing such blends.

These objectives were achieved by the following composition.
(A) a mineral oil-derived base oil having a saturate content of more than 90% by weight, a sulfur content of less than 0.03% by weight and a viscosity index of 80 to 150; and (b) a viscosity at 100 ° C. of 7 A lubricating base oil blend containing ˜30 cSt of a paraffinic base oil component, wherein component (b) is a percentage of recurring methylene carbon that is 4 or more carbons removed from the end groups and branches, and The base oil blend consisting of an isomerized Fischer-Tropsch derived bottom product, as measured by ¹³ C-NMR, in proportion to the percentage of isopropyl carbon atoms, less than 8.2. FIG. 1 shows the cloud point of a number of blends of mineral oil derived group II base oil (a) and paraffinic Fischer-Tropsch derived residual base oil component (b) 1-10 wt%. Also shows cloud point. The x-axis shows the amount (wt%) of GTL extra heavy base oil (XHBO) in the blend with 12 cSt Group II base oil. The y-axis indicates temperature (° C.). All blends were clear and crisp by definition because they had negative cloud points.

  For component (a), for example, lubricating base oils used to blend into engine and industrial oils are usually derived from a suitable set of mineral oil feedstocks from a predetermined set of properties, such as a generally wide range of temperatures. Over the course of various refining processes directed to obtain a lubricating base oil that maintains viscosity, oxidative stability and fluidity (as indicated by the viscosity index). The production of the lubricating base oil is conveniently performed as follows. Mineral crude oil is separated by atmospheric distillation into a number of distillate fractions and a residue known as long residue. The long residue is then separated by vacuum distillation into a vacuum distillate and a vacuum residue known as a short residue. A lubricating base oil is produced from the vacuum distillate fraction by a refining process. Aromatics and waxes are removed by these processes or are chemically converted from vacuum distillate fractions to acceptable distillate base oil molecular components. Asphalt can be removed from the short residue by a known deasphalting method. The deasphalted oil thus obtained is then freed of aromatics and waxes to yield a residual lubricating base oil known as bright stock. The wax obtained during refining of the various lubricating base oil fractions is designated “slack wax”. Lubricating base oils are usually obtained from suitable lubricating base oil fractions and / or deasphalted oils by suitable refining methods including catalytic and solvent quality improvement and dewaxing steps and catalytic hydrotreating.

  Mineral crude oil derived lubricant base oil is API publication 1509: Engine Oil Licensing and Certification System (Appendix E-API Base Oil Oil Engine Oil and Fuel Engine Fuel Engine). Also referred to as API Group I, II or III base oil as defined in Appendix E-API Base Oil Changeability Guidelines for Engine Oil). “Oil & Gas Journal, September 1, 1997, pp. 63-70, describes various methods of making API Group II base oils. Any of these possible methods can provide the desired saturate content. In order to obtain a base oil having a solvent extraction or hydrogenation of aromatics and other unsaturated compounds in one place, such as described in US-A-5935416, for example. Usually, the raw material is contacted with a hydrogenation catalyst, usually a Group VIII metal supported catalyst in the presence of hydrogen.

  While it is possible to obtain an API Group II base oil, ie, an API Group II base oil having a viscosity index of 120 or greater, this method is more difficult to obtain directly. Instead, this type of base oil is preferably obtained by hydrotreating slack wax obtained in a refining operation, for example as described in EP-A-178710. Alternatively, API Group III lubricant base oils can be produced by contacting waxy crude oil derived hydrocarbonaceous feedstock with hydroisomerization catalyst under hydroisomerization conditions and then recovering the high viscosity index lubricant base oil. Can be obtained directly from a feedstock containing a large amount of wax derived from a crude oil. Such a method is described, for example, in EP-A-0400742. In both cases, the maximum kinematic viscosity obtained for these base oils is measured by the maximum carbon number of the raw material represented by the number average molecular weight and molecular weight distribution of the raw material.

  In the base oil blend of the present invention, the mineral derived base oil component (a) is preferably 40 to 98 wt%, more preferably 50 to 97 wt%, more preferably 60 to 96, based on the total weight of the base oil blend. % By weight, more preferably 70-95% by weight, more preferably 80-94% by weight, more preferably 90-93% by weight. The balance is the paraffinic base oil component (b). The base oil blend component (a) preferably has a kinematic viscosity at 100 ° C of greater than 12.0 cSt, more preferably greater than 15.0 cSt, even more preferably greater than 20.0 cSt, and a viscosity index of preferably 95. More, more preferably more than 100. The viscosity index of component (a) is preferably 100 to 110, but can be relaxed by high VI of component (b).

The base oil blends of the present invention preferably have a cloud point of less than 0 ° C.
In the base oil blend of the present invention, component (a) is preferably an API Group II and / or API Group III base oil as defined in API Publication 1509.

  The Fischer-Tropsch derived paraffinic heavy base oil component (b) of the present invention is a heavy hydrocarbon composition containing 95% by weight or more of paraffin molecules. The heavy base oil component (b) of the present invention is preferably produced from Fischer-Tropsch wax and contains more than 98% by weight of saturated paraffinic hydrocarbons. Preferably these paraffinic hydrocarbon molecules are 85% by weight or more, more preferably 90% by weight or more, still more preferably 95% by weight or more, and most preferably 98% by weight or more are isoparaffinic. 85% by weight or more of the saturated paraffinic hydrocarbon is preferably an acyclic hydrocarbon. The naphthenic compound (paraffinic cyclic hydrocarbon) is preferably present in an amount of 15% by weight or less, more preferably less than 10% by weight.

  Fischer-Tropsch derived paraffinic base oil component (b) is a continuous series of continuous isoparaffins, ie carbonized with a continuous number of carbon atoms to ensure that it contains n, n + 1, n + 2, n + 3 and n + 4 carbon atoms. Contains hydrogen molecules. These continuous numbers of carbon atoms are the result of a Fischer-Tropsch hydrocarbon synthesis reaction, and the wax raw material obtained therefrom is isomerized to form component (b).

Furthermore, component (b) is a liquid at 100 ° C. and under ambient conditions, ie 25 ° C. and 1 atmosphere (101 kPa) absolute pressure.
The heavy hydrocarbon composition is normally liquid at the temperature and pressure conditions used and usually at ambient conditions of 24 ° C. and 1 atmosphere (101 kPa) pressure, although not necessarily.

The kinematic viscosity (VK100) at 100 ° C. of the component (b) is 7 cSt (7 mm ² / s) or more as measured by ASTM D-445. The kinematic viscosity at 100 ° C. of the heavy hydrocarbon composition of the present invention is preferably 10 cSt or more, more preferably 13 or more, still more preferably 15 or more, again more preferably 17 or more, still more preferably 20 or more, Most preferably, it is 25 or more. The kinematic viscosity described herein is measured according to ASTM D-445.

The boiling range distribution of samples with a boiling range above 535 ° C. is measured according to ASTM D-6352, while the boiling range distribution of lower boiling materials is measured according to ASTM D-2887.
The initial and final boiling point values referred to here are designations, and refer to the T5 cut point (boiling point) and T95 cut point (boiling point) obtained using the above method by gas chromatographic pseudodistillation (GCD).

  The initial boiling point of component (b) is preferably 400 ° C. or higher, more preferably 450 ° C. or higher, still more preferably 480 ° C. or higher, more preferably higher than 500 ° C., still more preferably higher than 540 ° C.

  Since conventional petroleum-derived hydrocarbons and Fischer-Tropsch derived hydrocarbons include mixtures of various molecular weights having a wide boiling range, this disclosure provides 10 wt% recovery points (recovered boiling points) and 90 wt% for each boiling range. Say the recovery point (recovery boiling point). The 10 wt% recovery point is the temperature at which 10 wt% of the hydrocarbons present in the cut (distillate) can be vaporized at atmospheric pressure and thus recovered. Similarly, the 90 wt% recovery point is the temperature at which 90 wt% of the hydrocarbons present in the cut are vaporized at atmospheric pressure. When referring to the boiling range distribution, this specification refers to the boiling range between the 10 wt% recovered boiling point and the 90 wt% recovered boiling point.

Component (b) of the present invention contains molecules having a continuous number of carbon atoms, and preferably contains 95% by weight or more of C30 + hydrocarbon molecules. More preferably, component (b) preferably contains at least 75% by weight of C35 + hydrocarbon molecules.
“Cloud point” refers to the temperature at which a sample begins to cloud, as measured according to ASTM D-5773. The cloud point of component (b) is usually from -60 ° C to + 49 ° C.

  In the base oil blend of the present invention, the pour point of component (b) is preferably less than -28 ° C. In the base oil blend of the present invention, since the component (b) has an unmeasurable pour point reducing effect on the base oil blend, the pour point of the base oil blend is the pour point of the component (a) and the component (b). And higher than both component (a) and component (b). The cloud point of component (b) is preferably 30 to -55 ° C, more preferably 10 to -50 ° C. Depending on the feedstock and dewaxing conditions, it has been found that some of the Fischer-Tropsch derived paraffinic heavy base oil component (b) has a cloud point higher than ambient temperature, but other properties are not adversely affected.

“Pour point” refers to the temperature at which a base oil sample begins to flow under carefully controlled conditions. The pour point referred to here is measured by ASTM D97-93.
Molecular weight is measured according to ASTM D-2503. The viscosity index VI is measured using ASTM D2270.
The viscosity index of component (b) of the present invention is preferably 120 to 170, more preferably 135 to 165, still more preferably 150 to 160.

  Component (b) preferably contains no or little sulfur and nitrogen compounds. This is common for products derived from Fischer-Tropsch reactions using synthesis gas containing almost no impurities. Component (b) contains sulfur, nitrogen and metal, preferably in the form of a hydrocarbon compound containing less than 50 ppmw (weight ppm), more preferably less than 20 ppmw, and even more preferably less than 10 ppmw. Most preferably, it contains sulfur and nitrogen, generally at a level below the detection limit. The detection limit is 5 ppm for sulfur and 1 ppm for nitrogen, for example when measured using X-rays or the Antek nitrogen test. However, sulfur may be introduced by using hydrosulfide hydrocracking / hydrodewaxing and / or sulfurized catalytic dewaxing catalysts.

  Furthermore, it has been found that there is a clear correlation between the kinematic viscosity, pour point and pour point lowering effect that an isomerized Fischer-Tropsch derived bottom product can have. For a given feed composition and bottom product boiling range (defined by a low cut point from the dewaxed distillate base oil and gas oil fractions), the pour point and the resulting viscosity are critical for the dewaxing process. It is connected. The pour point reducing effect has a pour point greater than -28 ° C, an average molecular weight of about 600 to about 1100, and a degree of branching in the molecule of 100 carbon atoms as disclosed in US-A-70553254. It has been found to be significant for isomerized Fischer-Tropsch derived bottom products having from about 6.5 to about 10 alkyl branches per unit.

  In the present invention, the Fischer-Tropsch derived paraffinic base oil component (b) is preferably separated as a residual fraction from the produced hydrocarbon during the Fischer-Tropsch synthesis reaction and subsequent hydrocracking and dewaxing steps.

  More preferably, this fraction is a distillation residue containing the highest molecular weight compounds still present in the product of the hydroisomerization process. The 10% by weight recovery boiling point of said fraction is preferably above 370 ° C, more preferably above 400 ° C and most preferably above 500 ° C in certain embodiments of the invention.

  Furthermore, the degree of branching in the molecule has more than 10 alkyl branches per 100 carbon atoms, measured according to the method disclosed in US-A-70553254.

  The Fischer-Tropsch derived paraffinic base oil component (b) of the present invention can be further specified by the content of different carbon species. More specifically, the Fischer-Tropsch derived paraffinic base oil component (b) has a proportion (%) of ε-methylene carbon atoms compared to the proportion (%) of isopropyl carbon atoms, ie, terminal groups and branches (further CH2> 4)), and can be specified by the ratio (%) of repeating methylene carbons, which are four or more carbons removed.

  The isomerized Fischer-Tropsch bottom product disclosed in US-A-70553254 differs from the isomerized Fischer-Tropsch derived paraffinic base oil component of the present invention in that the latter compound has a proportion of ε-methylene carbon atoms. (%) And the proportion of carbon atoms in the isopropyl branch (%) is usually high dewaxing harsh in that the overall ratio is 8.2 or more as measured for a Fischer-Tropsch derived base oil It was found that In particular, a Fischer-Tropsch product with a mild degree of isomerization, as disclosed in US-A-70553254, cannot obtain a clear and sharp blend, so it is in an amount greater than 1.5-2% by weight It has been found to be inappropriate to add.

  The measurable pour point lowering effect of the blend of substrates as disclosed in US-A-70553254 is the proportion (%) of ε-methylene carbon atoms and the proportion of carbon atoms in the isopropyl branch (%) in component (b). %) Was found to be achieved only when the ratio was greater than 8.2.

  Therefore, the pour point of the Fischer-Tropsch derived base oil component (b) of the present invention is less than -28 ° C. Since such component (b) has little or no pour point lowering effect, the pour point of the base oil blend containing components (a) and (b) is intermediate between the pour points of these components. .

The bifurcation and carbon composition of the Fischer-Tropsch derived base oil blending component, the following C ¹³ -NMR, vapor pressure osmometry (VPO), field ionization mass spectrometry field ionization mass spectrometry (FIMS) analysis of base oil samples using Can be measured more conveniently.

  The average molecular mass is obtained by the vapor pressure osmotic pressure method (VPO). The sample properties are then determined at the molecular level by nuclear magnetic resonance (NMR). The “Z” content and average carbon number are determined by FIMS.

Conventional NMR spectra have the problem of overlapping signals because of the large amount of isomers present in the base oil composition. To overcome the problem of signal duplication, selected multiple spectral subspectral carbon-13 nuclear magnetic resonance ( ^13C -NMR) analysis was utilized. In particular, gated spin echo (GASPE) was utilized to obtain a quantitative CH _n subspectrum. Quantitative data obtained from GASPE has better accuracy than data obtained with strain free reinforcement by polarization transfer (used in the method disclosed in DEPT, eg US-A-70553254).

  Based on the GASPE data and the average molecular mass obtained by the vapor pressure osmometry, the average number of branches and aliphatic rings can be calculated. Furthermore, based on GASPE, the distribution of the side chain length and the position of the methyl group along the straight chain is obtained.

Quantitative carbon diversity analysis is usually performed completely at room temperature. However, this is only applicable to materials that are liquid under such conditions. This method can be applied to any synthetic (eg, Fischer-Tropsch) derived or mineral oil derived base oil material that is either smoky at room temperature or a waxy solid and therefore cannot be manipulated by conventional methods. The NMR measurement method is as follows. As a measurement solvent for quantitative carbon diversity analysis, deuterium-substituted chloroform (CDCl ₃ ), which limits the maximum measurement temperature to 50 ° C. for practical reasons, is used. The base oil sample is heated to 50 ° C. in an oven until a clear liquid homogeneous product is formed. A portion of the sample is then transferred to the NMR tube. Any equipment used to move the NMR tube and sample is kept at this temperature. Add the identification solvent and shake the tube to dissolve the sample. In this case, the sample is reheated as necessary. To prevent solidification of the refractory material in the sample, the NMR instrument is maintained at 50 ° C. during data acquisition. Place the sample in the NMR instrument for a minimum of 5 minutes. This is necessary to equilibrate the temperature. The instrument must then be re-shimmed and readjusted. This is because these adjustments change at high temperatures. In this way, NMR data is obtained.

The CH ₃ subspectrum is obtained using a GASPE pulse sequence obtained by adding 1 / J GASPE (gated acquisition spin echo) to the CSE spectrum (standard spin echo). The resulting spectrum contains only the primary (CH ₃ ) and tertiary (CH) carbon peaks. Next, using the tabulated data, the various carbon branch carbon resonances are assigned to specific positions and lengths to correct for the chain ends. Subsequently, the sub-spectrum is integrated to give quantitative values for a variety of different CH ₃ signals as follows.

1) CH ₃ - carbon a. 25 ppm chemical shift (see against TMS)
b. 19 ppm and 21 ppm can be identified as methyl branches of the following general type (see Formula 1).

c. A clear strong signal in the 22-24 ppm region can be uniquely identified as an isopropyl end group having the following general structure (see Formula 2).


In this example, one of the methyl carbon atoms is classified as the end of the main chain, and the other methyl carbon atom is classified as a branch. Therefore, when calculating the methyl group content, the intensity of these signals is divided into two equal parts.

d. In addition, some weak signals in the 15-19 ppm region are considered to belong to the isopropyl group with an additional branch at the 3 position.
e. This spectrum shows a 3,3-dimethyl-substituted structure (formula 3) in the 8-8.5 ppm region:

Some weak signals that are most likely to be related to are observed.

In this case, the observed signal is for the terminal CH ₃ but there are two corresponding methyl branches. Therefore, the integral values of these signals are doubled (the signals for the two methyl branches are not calculated independently).

Thus, the overall assessment of methyl branch content is based on the following calculation (“Int” in Equation 4 represents the term “integration”). Σ (integral methyl) = Int 19-20 ppm + (Int 22-25 ppm) / 2 + Int 15-19 ppm + (Int 7.0-9 ppm) ^* 2
2) The calculation of ethyl branching is based on evidence from other peak assignments, assuming that the isopentyl end group content is negligible, and the two clear relative Based on strong signal. Thus, the calculation of ethyl branch content is simply based on the integration of the 10 to 11.2 ppm signal.

3) The total theoretical terminal CH ₃ content was calculated based on the “z” content and average carbon number measured by FIMS. Then C3 + branch content is known CH ₃ content from the theoretical terminal CH ₃ content, that is, half of the isopropyl value was determined by subtracting the value of the 3-methyl substituted value and the 3,3-dimethyl saturated structure . This gives values for signals in the 14 ppm region belonging to multiple CH _{3 s} that terminate in the CH ₃ chain. The difference is the value for C3 +.
Σ (integral C3 + branch) = Int 14 to 15 ppm-((theoretical terminal CH ₃ ) − (Int 11.2 to 11.8 ppm) − (Int 22 to 25 ppm) / 2−Int 7 to 9 ppm))

Furthermore, the present invention provides
(A) a mineral oil-derived base oil having a saturate content of more than 90% by weight, a sulfur content of less than 0.03% by weight, and a viscosity index of 80 to 150;
(B) Ratio of repetitive methylene carbon which is a paraffinic base oil component having a viscosity at 100 ° C. of 7 to 30 cSt (7 to 30 mm ² / s) and which is four or more carbons removed from the terminal groups and branches The base oil component consisting of an isomerized Fischer-Tropsch derived bottom product, wherein the ratio of (%) to the proportion of isopropyl carbon atoms (%) is less than 8.2 as measured by ¹³ C-NMR;
The present invention relates to a method for producing a lubricating base oil blend including a step of blending.

  Preferably, the present invention comprises (a) contacting a mineral oil derived feedstock as described above with hydrogen in the presence of a hydrogenation catalyst, and (b) the resulting product according to claims 1-7. A method for producing a lubricating base oil having a saturate content of greater than 90% by weight, a sulfur content of less than 0.03% by weight, and a viscosity index of 80 to 150, comprising a step of blending with a Fischer-Tropsch derived component Also related.

More preferably, the method comprises
(I) Mineral oil derived lubricating base oil precursor product having a saturate content of less than 90% by weight and a sulfur content of 300 ppmw to 2% by weight in the presence of hydrogen in the first hydrotreating stage at 250-350 ° C. Contacting with a suitable hydrotreating sulfide catalyst at a temperature,
(Ii) separating the effluent of step (i) into a gaseous fraction and a liquid fraction having a sulfur content of less than 50-1000 ppmw and a nitrogen content of less than 50 ppmw;
(Iii) contacting the liquid fraction of step (ii) with a catalyst having a noble metal component supported on an amorphous refractory oxide support in the second hydrotreating step in the presence of hydrogen;
(Iv) a step of recovering the lubricating base oil having the specific characteristics, and (v) a step of blending the base oil obtained in step (iv) with the paraffinic base oil component (b).
including.

  Preferably, the hydrotreating catalyst of step (i) contains at least one Group VIB metal component and a metal selected from the group consisting of iron, nickel, cobalt and a refractory oxide support.

  Even more preferably, the catalyst of step (i) is an alumina-supported nickel / molybdenum catalyst having a nickel content of 1-5% by weight as oxide and a molybdenum content of 10-30% by weight as oxide. More preferably, the catalyst of step (iii) contains platinum and palladium in which the total amount of platinum and palladium is 0.2 to 5% by weight, and an amorphous silica / alumina support.

  Lubricating base oil products are obtained by solvent extraction of petroleum fractions in the boiling range of the lubricating oil, followed by solvent dewaxing and / or catalytic dewaxing. The lubricating base oil product is an API Group I base oil, and the product obtained in step (d) is preferably an API Group II or Group III base oil.

Preferably, the paraffinic base oil component (b) is from a Fischer-Tropsch derived wax or waxy raffinate feedstock (a) at least 20% by weight of the compounds in the Fischer-Tropsch derived feedstock are compounds having 30 or more carbon atoms Hydrocracking / hydroisomerization of Fischer-Tropsch derived raw materials,
(B) separating the product of step (a) into one or more distillate fractions and a residual heavy fraction containing at least 10% by weight of a compound having a boiling point greater than 540 ° C .;
(C) performing a pour point lowering step on the residual fraction, and (d) isolating a Fischer-Tropsch derived paraffinic base oil component as a residual heavy fraction from the effluent of step (c),
Is a heavy column bottom distillate fraction obtained by

More preferably, the paraffinic base oil component (b) is derived from a Fischer-Tropsch derived wax or waxy raffinate raw material (a) a compound having 60 or more carbon atoms and a compound having 30 or more carbon atoms in the Fischer-Tropsch derived raw material. Hydrocracking / hydroisomerizing a Fischer-Tropsch derived raw material having a weight ratio of at least 0.2 and at least 30% by weight of the compounds in the Fischer-Tropsch derived raw material being a compound having 30 or more carbon atoms Process,
(B) the product of step (a) is mixed with one or more distillate fractions of a low boiling point fraction such that a T90 wt% boiling point of a wide range of base oil precursor fractions is in the range of 350-550 ° C; Separating the base oil precursor fraction into the heavy fraction,
(C) a step of performing a pour point reduction step on the wide range of base oil precursor fraction obtained in step (b), and (d) a heavy tower bottom distillate fraction by distillation of the product of step (c). Isolating into,
Is a heavy column bottom distillate fraction obtained by

  In addition to isomerization and rectification, the Fischer-Tropsch derived product fraction may be subjected to various other operations such as hydrocracking, hydrotreating and hydrofinishing.

  The raw material for step (a) is a Fischer-Tropsch derived product. The initial boiling point of the Fischer-Tropsch derived product may range up to 400 ° C, but is preferably less than 200 ° C. Prior to using the Fischer-Tropsch synthesis product in the hydroisomerization step, it is preferred that compounds having 4 or less carbon atoms and compounds having boiling points in that range are separated from the Fischer-Tropsch synthesis product. Examples of suitable Fischer-Tropsch methods are described in WO-A-9934917 and AU-A-698391. This disclosed method produces a Fischer-Tropsch product as described above.

  Fischer-Tropsch products contain no or very little sulfur and nitrogen containing compounds. This is normal for products derived from Fischer-Tropsch reactions using synthesis gas containing almost no impurities. Sulfur and nitrogen levels are generally currently below the limits of 5 ppm for sulfur and 1 ppm for nitrogen, respectively.

  Fischer-Tropsch products can be obtained by well-known methods such as the so-called Sasol method, Shell middle distillate synthesis method or Exxon Mobil “AGC-21” method. These and other methods are described in detail, for example, in EP-A-776959, EP-A-668342, US-A-4943672, US-A-5059299, WO-A-9934917 and WO-A-9990720. ing. This method generally comprises a Fischer-Tropsch synthesis and hydroisomerization steps as described in the literature. Fischer-Tropsch synthesis can be performed on syngas produced from any type of hydrocarbonaceous material, such as coal, natural gas, biological materials such as wood or hay. Fischer-Tropsch products obtained directly from the Fischer-Tropsch process usually contain a waxy fraction that is solid at room temperature.

Fischer-Tropsch wax used as a raw material for the method of the present invention is obtained by a well-known Fischer-Tropsch hydrocarbon synthesis method. Such Fischer-Tropsch synthesis generally produces hydrocarbons from a mixture of carbon monoxide and hydrogen in the presence of a suitable catalyst at high temperature and pressure. Fischer-Tropsch catalysts are usually selective for the production of paraffinic molecules, almost linear paraffins, and the products from Fischer-Tropsch synthesis reactions are usually a mixture of a very wide variety of paraffinic molecules. These hydrocarbons, which are gaseous or liquid at room temperature, are separated separately, for example as fuel gas (C5-), solvent feed and detergent feed (up to C17). Heavy paraffin (C18 +) is recovered as one or more wax fractions commonly referred to as Fischer-Tropsch wax or synthetic wax. For the purposes of the present invention, only these Fischer-Tropsch waxes are useful as raw materials and meet the above requirements for boiling range and freezing point. The Fischer-Tropsch wax feed has a boiling point such that the freezing point is preferably in the range of 55-150 ° C, more preferably in the range of 60-120 ° C, and / or T90-T10 is in the range of 50-130 ° C. Fischer-Tropsch wax having a melting point of less than 100 ° C has a kinematic viscosity (Vk100) at 100 ° C of preferably 3 cSt (3 mm ² / s) or more, preferably 3 to ¹² cSt, more preferably 4 to 10 cSt. Fischer-Tropsch wax with a melting point exceeding 100 ° C. has a kinematic viscosity at a temperature T that is 10 to 20 ° C. higher than the melting point, suitably 8 to 15 cSt, preferably 9 to 14 cSt.

  If the 10% by weight recovery boiling point of the raw material in step (a) is above 500 ° C, the wax content is preferably above 50% by weight. The raw material for the hydroisomerization step is preferably a Fischer-Tropsch product having 30% by weight or more, preferably 50% by weight or more, more preferably 55% by weight or more of a compound having 30 or more carbon atoms. Furthermore, the weight ratio of the compound having more than 30 and more than 60 carbon atoms and the compound having more than 30 and less than 60 carbon atoms in the Fischer-Tropsch product is at least 0.2, preferably at least 0.4, more preferably Is at least 0.55. The Fischer-Tropsch derived feed has an ASF-α value (Anderson-Schulz-Flory chain growth factor) of at least 0.925, preferably at least 0.935, more preferably at least 0.945, and even more preferably at least 0.955. It is preferable to contain the C20 + fraction.

  The Fischer-Tropsch product has an ASF-α value (Anderson-Schulz-Flory chain growth factor) of at least 0.925, preferably at least 0.935, more preferably at least 0.945, even more preferably at least 0.955. It is preferable to contain the C20 + fraction. In the Fischer-Tropsch wax raw material of step (a), the weight ratio of the compound having 60 or more carbon atoms and the compound having 30 or more carbon atoms in the Fischer-Tropsch derived raw material is preferably at least 0.2, more preferably Is at least 0.4.

  The hydroconversion / hydroisomerization reaction of hydroisomerization is preferably performed in the presence of hydrogen and a catalyst. Such catalysts can be selected from those known to those skilled in the art as being suitable for the reaction. The catalyst used for hydroisomerization usually has an acidic functionality and a hydrogenation-dehydrogenation functionality. A preferred acidic functionality is a refractory metal oxide support. Suitable carrier materials include silica, alumina, silica-alumina, zirconia, titania and mixtures thereof. Preferred support materials included in the catalyst used in the process of the present invention are silica, alumina and silica-alumina. A particularly preferred catalyst is constituted by supporting palladium on a silica-alumina support. For example, a catalyst containing a halogen compound such as fluorine requires special operating conditions and has environmental problems. Therefore, the catalyst preferably does not contain a halogen compound. Suitable hydrocracking / hydroisomerization processes and suitable catalysts are described in WO-A-0014179, EP-A-532118, EP-A-666894 and EP-A-776959.

  Preferred hydrogenation / dehydrogenation functionalities are Group VIII metals such as cobalt, nickel, palladium and platinum. A group VIII noble metal group, for example, palladium is preferable, and platinum is more preferable. In the case of platinum and palladium, the catalyst may contain a hydrogenation-dehydrogenation active component in an amount of 0.005 to 5 parts by weight, preferably 0.02 to 2 parts by weight per 100 parts by weight of the support material. When nickel is used, it is present in high content. Nickel is optionally used in combination with copper. A particularly preferred catalyst for use in the hydroconversion stage contains platinum in an amount of 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight per 100 parts by weight of support material. In order to increase the strength of the catalyst, the catalyst may contain a binder. The binder may be non-acidic. Examples of binders are clays and other binders known to those skilled in the art.

  In hydroisomerization, the feed is contacted with hydrogen at high temperature and pressure in the presence of a catalyst. The temperature is usually in the range of 175 to 380 ° C, preferably higher than 250 ° C, more preferably 300 to 370 ° C. The pressure is usually in the range from 10 to 250 bar, preferably from 20 to 80 bar. Hydrogen can be supplied at a gas hourly space velocity of 100-10000 Nl / l / hr, preferably 500-5000 Nl / l / hr. The hydrocarbon feedstock has an hourly space velocity of 0.1 to 5 kg / l / hr (feed mass / catalyst bed volume / hour), preferably more than 0.5 kg / l / hr, more preferably 2 kg / l. / Hr may be supplied. The ratio of hydrogen to hydrocarbon feed may range from 100 to 5000 Nl / kg, preferably from 250 to 2500 Nl / kg.

  The conversion in hydroisomerization, defined as the weight percent of feedstock having a boiling point higher than 370 ° C. per pass, reacts to a fraction having a boiling point lower than 370 ° C., is preferably at least 20% by weight, preferably Although it is at least 25% by weight, it is preferably 80% by weight or less, more preferably 70% by weight or less. The feedstock used in the above definition is a hydroisomerization total hydrocarbon feedstock, and therefore includes the amount optionally recycled in step (a).

  The product obtained by the hydroisomerization method preferably contains 50% by weight or more, more preferably 60% by weight or more, and still more preferably 70% by weight or more of isoparaffin, with the balance being n-paraffin and naphthenic compound. Consists of.

In step (b), the product of step (a) contains one or more distillate fractions and a residual heavy fraction containing 10% by weight or more of compounds whose boiling point exceeds 540 ° C.
This is expedient by separating one or more distillates from the hydroisomerization process effluent to obtain at least one middle distillate fuel fraction and a residual fraction used in step (c). Well achieved.

  Atmospheric distillation is first performed on the effluent of step (a). In certain preferred embodiments, the residual oil obtained by such distillation may be further distilled under near vacuum conditions until a fraction having a higher 10 wt% recovery boiling point is reached.

The 10 wt% recovery boiling point of the residual oil may preferably vary in the range of 350-550 ° C. The atmospheric pressure bottom product or residual oil preferably has a boiling point of more than 95% by weight exceeding 370 ° C.
This fraction may be used directly in step (c) or may be subjected to additional vacuum distillation at a pressure of 0.001 to 0.1 bar (absolute pressure). The raw material of step (c) is preferably obtained as the bottom product of such vacuum distillation.

  In the step (c), a catalytic pour point lowering step is performed on the heavy residual fraction obtained in the step (b). Step (c) may be performed using any hydroconversion process that can reduce the wax content to less than 50% by weight of the original wax content. The wax content in the intermediate product is preferably less than 35% by weight, more preferably 5 to 35% by weight, even more preferably 10 to 35% by weight. The freezing point of the product obtained in step (c) is preferably below 80 ° C. The intermediate product preferably has a boiling point in excess of 50% by weight, more preferably in excess of 70% by weight, exceeding the 10% recovery point of the wax feed used in step (a). The wax content used here is measured according to the following method. 1 part of the oil fraction to be measured is diluted with 4 parts of a mixture of methyl ethyl ketone and toluene (50/50 volume / volume) and then cooled to −20 ° C. in a refrigerator. The mixture is subsequently filtered at -20 ° C. The wax is thoroughly washed with cold solvent, removed from the filter, dried and weighed. Referring to the oil content, the weight% value means a value obtained by subtracting the wax content (wt%) from 100%.

  A possible method is the hydroisomerization method as described above for step (a). It has been found that wax can be reduced to the desired level using such catalysts. One skilled in the art can easily determine the required operating conditions to achieve the desired wax conversion by changing the severity of the process conditions as described above. However, the oil yield is optimized by optimizing a temperature of 300 to 330 ° C. and a space velocity per weight of 0.1 to 5 kg (oil) / l (catalyst) / hr, more preferably 0.1 to 3 kg / l / hr. Is particularly preferred.

  A more preferred type of catalyst applicable to step (c) is the type of dewaxing catalyst. The conditions applied when using such a catalyst must be such that the wax content remains in the oil. In contrast, conventional catalytic dewaxing methods aim to reduce the wax content to almost zero. With a dewaxing catalyst that includes molecular sieves, a number of weight molecules remain in the dewaxed oil. In this way, a more viscous base oil can be obtained.

  The dewaxing catalyst applicable to step (c) contains a combination of molecular sieve and optionally a metal having a hydrogenating function such as a Group VIII metal. Molecular sieves, more preferably molecular sieves with a pore size of 0.35 to 0.8 nm, showed good catalytic ability to reduce wax content in the wax feed. Suitable zeolites are mordenite, β, ZSM-5, ZSM-12, ZSM-22, ZSM-23, SSZ-32, ZSM-35 and ZSM-48 or combinations thereof. Another preferred molecular sieve group is the silica-alumina phosphate (SAPO) material, of which SAPO-11 is most preferred, as described, for example, in US-A-4859311. ZSM-5 may optionally be used in the form of HZSM-5 in the absence of a Group VIII metal. Other molecular sieves are preferably used in combination with a Group VIII metal added. Preferred Group VIII metals are nickel, cobalt, platinum and palladium. Examples of possible combinations are Pt / ZSM-35, Ni / ZSM-5, Pt / ZSM-23, Pd / ZSM-23, Pt / ZSM-48 and Pt / SAPO-11, or Pt / Zeolite β. It is a stacked structure of Pt / ZSM-23, Pt / zeolite β and Pt / ZSM-48, or Pt / zeolite β and Pt / ZSM-22. Further details and examples of suitable molecular sieve and dewaxing conditions can be found, for example, in WO-A-9718278, US-A-4434369, US-A-5053373, US-A-5252527, US-A-20040065581, US-A- 45704043 and EP-A-1029029.

  Other preferred types of molecular sieves are those having relatively low isomerization selectivity and high wax conversion selectivity such as ZSM-5 and ferrierite (ZSM-35).

  The dewaxing catalyst preferably also contains a binder. The binder may be a synthetic or naturally occurring (inorganic) material such as clay, silica, and / or metal oxide. Naturally occurring clays are, for example, montmorillonite and kaolin families. The binder is preferably a porous binder material such as refractory oxides such as alumina, silica-alumina, silica-magnesia, silica-zirconia, silica-tria (thorium oxide), silica-berylria (beryllium oxide), silica-titania, There are ternary compositions such as silica-alumina-tria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. It is further preferred to use a low acidity refractory oxide binder material that is essentially free of alumina. Examples of these binder materials include silica, zirconia, titanium dioxide, germanium dioxide, boria and mixtures of two or more of these as described above. The most preferred binder is silica.

  A preferred type of dewaxing catalyst comprises intermediate zeolite crystallites as described above and a low acidity refractory oxide that is essentially free of aluminum. The surface of the aluminosilicate zeolite microcrystal is modified by surface dealumination. A preferred dealumination treatment is by contacting the binder and zeolite extrudates with an aqueous solution of a fluorosilicate salt, for example as described in US-A-5157191 or WO-A-0029511. Examples of suitable dewaxing catalysts as described above are silica-bonded dealuminated Pt / ZSM-5, silica-bonded dealuminated Pt / ZSM as described, for example, in WO-A-0029511 and EP-B-832171. -35.

  The conditions of step (c) when using a dewaxing catalyst usually include an operating temperature in the range of 200-500 ° C, preferably 250-400 ° C. The operating temperature is preferably 300-330 ° C. Hydrogen pressure in the range of 10-200 bar, preferably 40-70 bar, 0.1-10 kg (kg / l / hr) of oil per liter of catalyst per hour, preferably 0.1-5 kg / l / hr More preferred are hourly space velocities (WHSV) in the weight range of 0.1 to 3 kg / l / hr and hydrogen to oil ratios in the range of 100 to 2,000 liters of hydrogen per liter of oil.

  If more than about 30% per pass in step (c), the yield and pour point are reduced exponentially until a further plateau reaches a pour point in the range of -50 to -60 ° C. It was found. It has also been found that the resulting isomerized Fischer-Tropsch derived bottom product with a pour point of less than -28 ° C exhibits a significantly reduced pour point reducing effect or no longer decreases the pour point.

  At the same time, however, the isomerized Fischer-Tropsch derived bottom product with a lowered pour point can be added to the mineral base oil component (a) in order to achieve a high viscosity without raising the cloud point above ambient temperature. Was found.

  In step (d), the product of step (c) is usually sent to a vacuum tower where various distillate base oil fractions are collected. These distillate base oil fractions may be used to produce a lubricating base oil blend or may be broken down into low boiling products such as diesel or naphtha. The residual material collected from the vacuum tower contains a mixture of high boiling hydrocarbons and is used to produce component (b) of the present invention.

  Furthermore, the product obtained in step (c) may be subjected to an additional treatment such as solvent dewaxing. The product obtained with the process according to the invention can be further treated in a clay treatment process or in contact with activated carbon, for example as described in US-A-479546 and EP-A-712922, in order to improve the stability. Can do.

  The addition of component (b), due to its high saturation level, very low pour point and high viscosity index, made it possible to achieve the target values for kinematic viscosity, pour point and viscosity index at 100 ° C. It has been found that when used in blends according to the invention, the saturates level, pour point and viscosity index can be relaxed. Therefore, the cracking severity of the mineral oil feedstock is reduced, which provides the advantage of improved yield for the mineral oil feedstock. Accordingly, the subject of the invention is also (a) contacting a mineral oil derived feedstock as described above with hydrogen in the presence of a hydrogenation catalyst, and (b) A method for producing a lubricating base oil having a saturate content of greater than 90% by weight, a sulfur content of less than 0.03% by weight, and a viscosity index of 80 to 150, comprising a step of blending with a Tropsch derived component (b) About.

In addition, API Group II based formulations with low additive treatment, and thus low additive thickening, such as SAE 40 or 50 single grade gas engine oil, could be achieved with the blends of the present invention. SAE kinematic viscosity requirement at ^{100 ℃ 12.5mm 2 / s (cSt} ) or more, or each 16.3 mm ² / s, so (cSt), is difficult.

The product obtained with the process according to the invention can be further treated in a clay treatment process or in contact with activated carbon, for example as described in US-A-479546 and EP-A-712922, in order to improve the stability. Can do.
The invention is illustrated by the following non-limiting examples.

Manufacture of de-leakage catalyst Tetraethylammonium bromide as prototype using micropores and mesopores materials, Vol. 22 (1998), pp. 644-645, “Verified synthesis of zeolitic materials” Microcrystals were produced. The particle size visually observed with a scanning electron microscope (SEM) was 1-10 μm ZSM-12. The average crystallite size measured by the XRD line expansion method was 0.05 μm. The microcrystals thus obtained were extruded together with a silica binder (zeolite 10% by weight, silica binder 90% by weight). The extrudate was dried at 120 ° C. A solution of (NH ₄ ) ₂ SiF ₅ (45 ml of a 0.019 N solution per gram of zeolite microcrystals) was poured into the extrudate. The mixture was then heated at 100 ° C. under reflux for 17 hours with gentle stirring on the extrudate. After filtration, it was washed twice with deionized water, dried at 120 ° C. for 2 hours, and calcined at 480 ° C. for 2 hours.

  The extrudate thus obtained was impregnated with an aqueous solution of platinum tetramine hydroxide, then dried (at 120 ° C. for 2 hours) and fired (at 300 ° C. for 2 hours). Platinum in the catalyst was reduced at a temperature of 350 ° C. for 2 hours under a hydrogen flow rate of 100 liters / hour to activate the catalyst. The obtained catalyst was obtained by supporting 0.35% by weight of Pt on dealuminated silica-bonded MTW zeolite.

Example 1 Production of Fischer-Tropsch Derived Component (b) A hydrocracked / hydroisomerized Fischer-Tropsch derived wax containing 80% by weight or more of isoparaffin having the characteristics shown in Table 1 was distilled. A light base oil precursor fraction having a boiling point in the range of about 390 to 520 ° C. and a residual heavy fraction having a boiling point exceeding 520 ° C. were obtained.

  The residual heavy fraction was contacted with the aforementioned dewaxing catalyst. The dewaxing conditions were: hydrogen pressure 40 bar, WHSV = 1 kg / l. h, temperature 340 ° C., hydrogen gas flow rate = 700 Nl / kg (raw material). The dewaxed oil was separated by distillation into a light base oil component and a heavy base oil component having the characteristics shown in Table 2.

Example 2
Mineral oil-derived API Group I bright stock having a viscosity index of 95 and a kinematic viscosity at 100 ° C. of 32 cSt is subjected to the Fischer-Tropsch derived base oil components A, B and C of the present invention and the dewaxing step with reduced severity. The resulting comparative base oil components A and B were blended.

The limit when the mixture still has a negative cloud point and is therefore clear and clear is measured by making several blends of different concentrations. A few days after the addition of the Fischer-Tropsch derived component, the limit at which a clear and brilliant blend could be reached at ambient temperature is shown as the clear and clear limit. Comparative Fischer-Tropsch derived bottoms product, i.e., CH 2> ₄ comparative limit of the weight percent ratio of carbon in weight percent versus isopropyl carbons in _(all from C) is more than 8.2 Was clearly below the limit of the Fischer-Tropsch derived (FT) component of the present invention.

Example 3: Blend with API Group II Base Oil Another set of blends was made with API Group II base oil and the Fischer-Tropsch derived (FT) component of the present invention. The properties of the starting components are shown in Table 4.

  In order to determine the ratio at which the cloud point was positive, various blends were made with increasing amounts of the base oil and group II base oil. These blends were made by heating the mixture of the two components to about 50 ° C. under agitation until the blend was clear and light, and then cooling the blend to ambient temperature (25 ° C.). The blend was then held at ambient temperature for 24 hours, 3 days and 7 days, at which time the appearance was examined (see Table 5).

  The above results clearly show that the homogeneous blend of the present invention can be produced with a high content of paraffinic Fischer-Tropsch derived residual base oil component. Although the limit at which a negative cloud point was obtained was limited to the addition of about 5% by weight of the Fischer-Tropsch component, similar behavior was seen for blends containing mineral oil derived Group III base oils.

Figure 2 shows the cloud point and pour point of a number of blends of mineral oil derived group II base oil (a) and 1-10 wt% of paraffinic Fischer-Tropsch derived residual base oil component (b). The horizontal axis represents the amount (wt%) of GTL extra heavy base oil (XHBO) in the blend of the present invention, and the vertical axis represents temperature (° C.).

US-A-70553254 US-A-5935416 EP-A-178710 WO-A-9934917 AU-A-698391 WO-A-0014179 EP-A-532118 EP-A-666894 EP-A-776959 US-A-4859311 WO-A-9718278 US-A-4343692 US-A-5053373 US-A-5252527 US-A-20040065581 US-A-45744033 EP-A-1029029 US-A-479546 EP-A-712922

Micropores and mesopores materials, Vol. 22 (1998), pp. 644-645, “Verified synthesis of zeolitic materials”

Claims (10)

(A) a mineral oil-derived base oil having a saturate content of more than 90% by weight, a sulfur content of less than 0.03% by weight and a viscosity index of 80 to 150; and (b) a viscosity at 100 ° C. of 7 A lubricating base oil blend containing ˜30 cSt (7-30 mm ² / s) paraffinic base oil component, wherein component (b) is a repeat of 4 or more carbons removed from end groups and branches The group consisting of an isomerized Fischer-Tropsch derived bottom product in which the ratio of the percentage of methylene carbon to the percentage of isopropyl carbon atoms (%) is less than 8.2 as determined by ¹³ C-NMR Oil blend.   The base oil blend according to claim 1, wherein the mineral oil derived base oil component (a) is present in an amount of 40 to 95% by weight relative to the total weight of the base oil blend.   The base oil blend of claim 1 or 2, wherein the blend has a kinematic viscosity at 100 ° C greater than 12.0 cSt and a viscosity index greater than 95.   The base oil blend according to any one of claims 1 to 3, wherein the viscosity index of component (a) is 100 to 110.   The base oil blend of any one of claims 1-4, wherein the cloud point of the blend has a value less than 0 ° C.   The base oil blend according to any one of claims 1 to 5, wherein the base oil component (a) is an API Group II and / or API Group III base oil as defined in API Publication 1509.   The base oil blend according to any one of claims 1 to 6, wherein the pour point of component (b) is less than -28 ° C. (A) a mineral oil-derived base oil having a saturate content of more than 90% by weight, a sulfur content of less than 0.03% by weight, and a viscosity index of 80 to 150;
(B) Ratio of repetitive methylene carbon which is a paraffinic base oil component having a viscosity at 100 ° C. of 7 to 30 cSt (7 to 30 mm ² / s) and which is four or more carbons removed from the terminal groups and branches The base oil component consisting of an isomerized Fischer-Tropsch derived bottom product, wherein the ratio of (%) to the proportion of isopropyl carbon atoms (%) is less than 8.2 as measured by ¹³ C-NMR;
A method for producing a lubricating base oil blend comprising the step of blending.   The process according to claim 9, wherein the average degree of branching in the molecule of component (b) is greater than 10 alkyl branches per 100 carbon atoms. The paraffinic base oil component (b) is a Fischer-Tropsch derived wax or waxy raffinate raw material. (A) Weight of a compound having 60 or more carbon atoms and a compound having 30 or more carbon atoms in the Fischer-Tropsch derived raw material Hydrocracking / hydroisomerizing a Fischer-Tropsch derived raw material in which the ratio is at least 0.2 and at least 30% by weight of the compounds in the Fischer-Tropsch derived raw material are compounds having 30 or more carbon atoms;
(B) the product of step (a) is mixed with one or more distillate fractions of a low boiling point fraction such that a T90 wt% boiling point of a wide range of base oil precursor fractions is in the range of 350-550 ° C; Separating the base oil precursor fraction into the heavy fraction,
(C) a step of performing a pour point reduction step on the wide range of base oil precursor fraction obtained in step (b), and (d) a heavy tower bottom distillate fraction by distillation of the product of step (c). Isolating into,
The method according to any one of claims 13 to 19, which is a heavy bottom distillate fraction obtained by