Patent Grant
8784643
This invention is directed to base stocks with defined boiling ranges, viscosity indexes, Noack volatilities, and/or CCS VIS at −25° C. This invention is also directed to a base stock slate of these base stocks, a process to manufacture these base stocks, the base stock made by a process, and a base oil manufacturing plant.
The term “comprising” refers to the demerits or steps that are identified following that term, but any such elements or steps are not exhaustive, and an embodiment may include other elements or steps.
The phrase “Consecutive numbers of carbon atoms” refers to the base oil has a distribution of hydrocarbon molecules over a range of carbon numbers, with every number of carbon numbers in-between. For example, the base oil may have hydrocarbon molecules ranging from C22 to C36 or from C30 to C60 with every carbon number in-between. The hydrocarbon molecules of the base oil differ from each other by consecutive numbers of carbon atoms, as a consequence of the waxy feed used to make the base oil also having consecutive numbers of carbon atoms. For example, in the Fischer-Tropsch hydrocarbon synthesis reaction, the source of carbon atoms is CO and the hydrocarbon molecules are built up one carbon atom at a time. Petroleum-derived waxy feeds have consecutive numbers of carbon atoms. In contrast to an oil based on polyalphaolefin, the molecules of a base oil made from a waxy feed having consecutive numbers of carbon atoms have a more linear structure, comprising a relatively long backbone with short branches. The classic textbook description of a polyalphaolefin is a star-shaped molecule, and in particular tridecane, which is illustrated as three decane molecules attached at a central point. While a star-shaped molecule is theoretical, nevertheless polyalphaolefin molecules have fewer and longer branches that the hydrocarbon molecules that make up the base oil disclosed herein.
The term “base stock” refers to a lubricant component that is produced by a single manufacturer to the same specifications (independent of feed source or manufacturer's location); that meets the same manufacturer's specification; and that is identified by a unique formula, product identification number; or both. Base stocks may be manufactured using a variety of different processes including but not limited to distillation, solvent refining, hydrogen processing, oligomerization, esterification, and re-refining.
The term “base oil” refers to a base stock or blend of different base stocks. It is suitable for blending with additives into finished lubricants meeting desired specifications.
The term “base stock slate” refers to a product line of base stocks that have different viscosities but are in the same base stock grouping and from the same manufacturer.
The term “Block dewaxing” refers to a catalytic dewaxing process wherein a separated fraction from a waxy hydrocarbon, having a narrower boiling range than the waxy hydrocarbon, is upgraded into a base stock. It is contrasted with “bulk dewaxing” where a broad boiling range waxy hydrocarbon is catalytically dewaxed, and wherein one or more separating steps to produce a base stock are done following the catalytic dewaxing step.
The phrase “light neutral base oil” refers to a boiling range of approximately 650° F. to 900° F. (343° C. to 482° C.), a pour point not greater than about −5° C., and a kinematic viscosity at 100° C. of about 4 to about 5 mm2/s.
The phrase “highly paraffinic unconventional base oil” refers to a Group II or Group III base oil having greater than 72% paraffinic carbon and less than 30% naphthenic carbon by n-d-M analysis.
Test Method Descriptions:
“N-d-M” analysis is done by ASTM D3238-95 (Reapproved 2005) with normalization. ASTM D3238-95 (Reapproved 2005) is the Standard Test Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n-d-M Method. This method is for “olefin free” feedstocks which are assumed in this application to mean that that olefin content is 2 wt % or less. The normalization process consists of the following: A) If the Ca value is less than zero, Ca is set to zero, and Cn and Cp are increased proportionally so that the sum is 100%. B) If the Cn value is less than zero, Cn is set to zero, and Ca and Cp are increased proportionally so that the sum is 100%; and C) If both Cn and Ca are less than zero, Cn and Ca are set to zero, and Cn is set to 100%.
“Boiling range” is the 5 wt % boiling point to the 95 wt %, inclusive of the end points, as measured by ASTM D 6352-04 and referred to herein as SimDist. A hydrocarbon with a boiling range of 700 to 900° F., for example, has a 5 wt % boiling point greater than 70° F. and a 95 wt % boiling point less than 900° F.
“Kinematic viscosity” is a measurement in mm2/s of the resistance to flow of a fluid under gravity, determined by ASTM D445-06.
“Viscosity index” (VI) is an empirical, unit-less number indicating the effect of temperature change on the kinematic viscosity of the oil. The higher the VI of an oil, the lower its tendency to change viscosity with temperature. VI is measured according to ASTM D 2270-04.
“Cold-cranking simulator apparent viscosity” (CCS VIS) is a measurement in millipascal seconds, mPa·s, to measure the viscometric properties of lubricating base oils under low temperature and low shear, CCS VIS is determined by ASTM D 5293-04.
“Noack volatility” is defined as the mass of oil, expressed in weight %, which is lost when the oil is heated at 250° F. with a constant flow of air drawn through it for 60 minutes, measured according to ASTM D5800-05, Procedure B.
“Pour point” is a measurement of the temperature at which a sample of base oil will begin to flow under certain carefully controlled conditions, which can be determined as described in ASTM D 5950-02.
“Flash point” is a measure of the tendency of the base oil to form a flammable mixture with air under controlled laboratory conditions. It is measured using a Cleveland open cup apparatus (manual or automated), by ASTM D 92-05a.
“Oxidator BN” measures the response of a base oil in a simulated application. High values, or long times to adsorb one liter of oxygen, indicate good stability. Oxidator BN can be measured via a Dornte-type oxygen absorption apparatus (R. W. Donne “Oxidation of White Oils,” Industrial and Engineering Chemistry, Vol. 28, page 26, 1936), under 1 atmosphere of pure oxygen at 340° F. The time, in hours, to absorb 1000 ml of O2 by 100 grams of oil is reported, In the Oxidator BN test, 0.8 ml of catalyst is used per 100 grams of oil The catalyst is a mixture of soluble metal-naphthenates simulating the average metal analysis of used crankcase oil. The additive package is 80 millimoles of zinc bispolypropylenephenyldithlophosphate per 100 grams of oil.
“Weight percent aromatics” gives an indication of the UV and oxidation stability of a base oil. It can be measured by HPLC-UV. In one embodiment, the test is conducted using a Hewlett Packard 1050 Series Quaternary Gradient High Performance Liquid Chromatography (HPLC) system, coupled with a HP 1050 Diode-Array UV-Vis detector interfaced to an HP Chem-station. Identification of the individual aromatic classes in the base oil can be made on the basis of the UV spectral pattern and the elution time. The amino column used for this analysis differentiates aromatic molecules largely on the basis of their ring-number (or double-bond number). Thus, the single ring aromatic containing molecules elute first, followed by the polycyclic aromatics in order of increasing double bond number per molecule. For aromatics with similar double bond character, those with only alkyl substitution on the ring elute sooner than those with naphthenic substitution. Unequivocal identification of the various base oil aromatic hydrocarbons from their UV absorbance spectra can be accomplished recognizing that their peak electronic transitions are all red-shifted relative to the pure model compound analogs to a degree dependent on the amount of alkyl and naphthenic substitution on the ring system. Quantification of the elating aromatic compounds can be made by integrating chromatograms made from wavelengths optimized for each general class of compounds over the appropriate retention time window for that aromatic. Retention time window limits for each aromatic class can be determined by manually evaluating the individual absorbance spectra of eluting compounds at different times and assigning them to the appropriate aromatic class based on their qualitative similarity to model compound absorption spectra.
Base Stock
We have developed a base stock, comprising hydrocarbons with consecutive numbers of carbon atoms, in one embodiment the base stock has a boiling range from 730 to 1000° F. (388 to 538° C.); a VI from 105 to less than 130; and a Noack volatility from 5 to 11.5 wt %; and less than 0.1% total aromatics. In a second embodiment, the base stock has a boiling range from 730 to 1000° F. (388 to 538° C.); a VI from 105 to less than 130; and a CCS VIS at −25° C. from 2000 to 4500 mPa·s; and less than 0.1% total aromatics.
The VI is less than 130, which keeps the base stock within the VI limits for a Group II and Group III base oils. The VI is generally from 105 to less than 130, but in other embodiments may be from 110 to less than 130, from 113 to less than 130, from 115 to less than 129, from 115 to less than 120, or from 124 to less than 129. The Noack volatility is generally in a range from 6 to 12 wt %, and in one embodiment is from 5 to 11.5 wt %. In other embodiments the Noack volatility may be from 5.5 to 11 wt %, from 6 to 10 wt %, from 6 to 9.5 wt %, from 6 to 7 wt %, or from 8 to 9 wt %.
In some embodiments the base stock has a ratio of the Noack volatility to a CCS VIS at −25° C. multiplied by 100 in a specified range. The range may be from 0.10 to 0.60, from 0.15 to 0.40, from 0.20 to 0.35, or from 0.20 to 0.30.
The base stock may further comprise a second base stock. In one embodiment the second base stock is a Group II base oil. Group II, Group III, and Group IV base oils are defined in Appendix E of the API 1509 specification, April 2008, A Group II base oil has greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and has a VI greater than or equal to 80 and less than 120. A Group III base oil has greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and has a VI greater than or equal to 120. A Group IV base oil is a polyalphaolefin.
In one embodiment the second base stock has a kinematic viscosity at 40° C. from 40.00 to 46.00 mm2/s. An example of this second type of base stock is Chevron 220R.
In another embodiment the second base stock is a 110 Neutral base oil. 110 Neutral base oils have a SUS viscosity at 100° F. of approximately 110. One example is ConocoPhillips 110N. Another example is a “110N” comprising Fischer-Tropsch derived base oil. This for example may be a blend of Fischer-Tropsch derived base oil, Chevron 220R, and Ergon Hygold 100. This example is fully described in U.S. patent application Ser. No. 12/047,887, filed Mar. 13, 2008. Kinematic viscosity in mm2/s at 100° F. can be converted to SUS viscosity at 100° F. according to the arithmetic and the reference table provided in ASTM D 2161-05. In one embodiment the 110 Neutral base oil has a second boiling range from 700 to 925° F. (371 to 496° C.), a second VI from 105 to 119, and a second volatility less than 18 wt %, and less than 0.1% total aromatics. This second base stock is fully described in our co-filed patent application Ser. No. 12/481,827 (A 110 Neutral Base Oil with Improved Properties).
In another embodiment the base stock may further comprise a third base stock. The third base stock can be a Group II base oil.
In one embodiment the base stock comprises a second base stock that has a kinematic viscosity at 40° C. from 40.00 to 46.00 mm2/s and a third base stock that is a Group II base oil. The third base stock may have a third boiling range from 700 to 925° F. (371 to 496° C.), a third VI from 105 to 115, and a third Noack volatility less than 18 wt %.
In one embodiment the base stock is comprised entirely of Group II base oils, in another embodiment the base stock is comprised of Group II and Group III base oils.
One feature of the base stock is that it can be blended into a wide variety of high quality finished lubricants by blending the base stock with one or more additives. Examples of finished lubricants that can be made from the base stock include engine oils, greases, heavy duty motor oils, passenger car motor oils, transmission and torque fluids, natural gas engine oils, marine lubricants, railroad lubricants, aviation lubricants, food processing lubricants, paper and forest products, metalworking fluids, gear lubricants, compressor lubricants, turbine oils, hydraulic oils, heat transfer oils, barrier fluids, and other industrial products. In one embodiment the base stock can be blended into a multigrade engine oil. Examples of multigrade engine oils that can be blended with the base stock are 5W-XX, 10W-XX, and 15W-XX, wherein XX is selected from the group consisting of 20, 30, 40, 50, and 60.
Another feature is that the severity of the hydrocracking conditions may be increased from the conditions that yielded the first base stock and the second base stock (i.e., Chevron 170RLV and Chevron 110RLV) to afford an alternate first base stock and an alternate second base stock (i.e., Chevron 170RLV2 and Chevron 110RLV2) with a lower CCS VIS at −25° C. and a lower Noack volatility as shown with Example 2 and Table II.
One advantage of the Chevron 170RLV base stock Is that it can be blended into finished lubricants without using expensive and highly processed base oils that are very expensive. For example, the finished lubricant may have less than 20 wt %, less than 10 wt %, less than 5 wt %, or no Group III or Group IV base oil. Alternatively, the finished lubricant may have less than 20 wt %, less than 10 wt %, less than 5 wt %, or no highly paraffinic unconventional base oil
One advantage of the Chevron 170RLV2 base stock is that it can be blended into finished lubricants without using expensive correction fluids (e.g., PAO). For example the finished lubricant may have less than 20 wt %, less than 10 wt %, less than 5 wt %, or no Group IV base oil.
Base Stock Slate
We have developed a base stock slate comprising a first base stock and an additional base stock. The first base stock has a first boiling range from 730 to 1000° F. (388 to 538° C.), a first VI from 105 to less than 130, a first Noack volatility from 5 to 11.5 wt %, and a first CCS VIS at −25° C. from 2000 to 4500 mPa·s. This is the same base stock as described earlier in this specification, and can have alternate embodiments within these general ranges of properties as described previously.
The second base stock has an additional boiling range from 700 to 925° F. (371 to 496° C.), an additional VI from 105 to 115, and an additional Noack volatility less than 18 wt %. This base stock is described in our co-filed patent application titled “A 110 Neutral Base Oil with Improved Properties”. In one embodiment the additional base stock has a ratio of the additional Noack volatility to an additional CCS VIS at −25° C. multiplied by 100 from 0.80 to 1.55. In other embodiments the ratio of the additional Noack volatility to the additional CCS VIS at −25° C. multiplied by 100 may be from 0.90 to 1.40, from 0.90 to 1.30, or from 1.0 to 1.30.
In one embodiment the first base stock has a ratio of the first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 from 0.15 to 0.40. In other embodiments the ratio of the first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 may be from 0.1 to 0.60, from 0.20 to 0.35, or from 0.20 to 0.30.
In one embodiment of the base stock slate, the first base stock (i.e., Chevron 170RLV) and the additional base stock are both Group II base oils. A base stock slate with ail Group II base oils gives a technical advantage to formulators of finished lubricants who wish to blend with all Group II base oils. This is especially an advantage for formulators of engine oils who wish to reduce the expenses of testing required for base oil interchanges between different groups of base oils.
In another embodiment of the base stock slate, the first base stock (i.e., Chevron 170RLV2) and the additional base stock are Group III and Group II base oils, respectively. A base stock slate with Group III and Group II base oils gives a technical advantage to formulators of finished lubricants who wish to blend with either Group III or Group II base oils. This is especially an advantage for formulators of engine oils who wish to blend from a slate with a higher viscosity index, lower CCS VIS at −25° C. and a lower Noack volatility. As can be seen by the chart shown in FIG. 1, the Chevron 110RLV2 and Chevron 170RLV2 base stocks have additional blending power and efficiency towards 5W-XX engine oils, as least.
Process to Manufacture Base Stock
We provide a process to manufacture a base stock, comprising hydrocracking, separating, and dewaxing. The hydrocracking is done by hydrocracking a heavy hydrocarbon feedstock in a hydrocracking zone. The hydrocracking zone may be a reactor specifically designed for hydrocracking. The operating conditions are selected to convert the heavy hydrocarbon feedstock to a product slate containing greater than 30 wt % of a waxy intermediate fraction. The intermediate traction is separated into a lower boiling fraction and a higher boiling fraction. The higher boiling fraction is dewaxed under conditions whereby the dewaxed higher boiling fraction has a first boiling range from 730 to 1000° F. (388 to 538° C.), a first VI from 105 to 130, a first CCS VIS at −25° C. from 2000 to 4500 mPa·s, and a ratio of a first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 from 0.15 to 0.40.
In one embodiment, the process also includes dewaxing the lower boiling fraction under conditions whereby the dewaxed lower boiling traction has an additional boiling range from 700 to 925° F. (371 to 496° C.), an additional VI from 105 to 115, and an additional Noack volatility less than 18 wt %.
The dewaxing may be done by a number of different processes, including hydroisomerization dewaxing, solvent dewaxing, or a combination thereof. An integrated process for preparing a base stock having an exceptionally high VI, including a hydroisomerization step followed by a solvent dewaxing step, is described in U.S. Pat. No. 7,074,320. An alternate process comprising solvent dewaxing followed by catalytic dewaxing is described in U.S. Pat. No. 4,622,130.
Hydrocracking
The operating conditions in the hydrocracking zone are selected to convert a heavy hydrocarbon feedstock to a product slate containing greater than 30 wt % of a waxy intermediate fraction which is upgraded to the original base oil. In different embodiments the operating conditions in the hydrocracking zone can be selected to convert a heavy hydrocarbon feedstock to a product slate containing from greater than 30 wt %, from greater than 32 wt %, or from greater than 34 wt % of a waxy intermediate fraction. In different embodiments the operating conditions in the hydrocracking zone can be selected to convert a heavy hydrocarbon feedstock to a product slate containing less than 60 wt %, less than 50 wt %, less than 40 wt %, or less than 35 wt % of a waxy intermediate fraction. In one embodiment the operating conditions in the hydrocracking zone are selected to convert a heavy hydrocarbon feedstock to a product slate containing from greater than 30 wt % to less than 40 wt % of a waxy intermediate.
The temperature in the hydrocracking zone will be within the range of from about 500° F. (260° C.) to about 900° F. (480° C.), such as within the range of from about 650° F. (345° C.) to about 800 CF (425° C.). A total pressure above 1000 psig is used. For example the total pressure can be above about 1500 psig, or above about 2000 psig. Although greater maximum pressures have been reported in the literature and may be operable, the maximum practical total pressure generally will not exceed about 3000 psig. Liquid hourly space velocity (LHSV) will usually fall within the range of from about 0.2 to about 5.0, such as from about 0.5 to about 1.5. The supply of hydrogen (both make-up and recycle) is preferably in excess of the stoichiometric amount needed to crack the target molecules and will usually fall within the range of from about 500 to about 20,000 standard cubic feet (SCF) per barrel. In one embodiment the hydrogen will be within the range from about 2000 to about 10,000 SCF per barrel.
The catalysts used in the hydrocracking zone are composed of natural and synthetic materials having hydrogenation and dehydrogenation activity. These catalysts are pre-selected to crack the target molecules and produce the desired product slate. The hydrocracking catalyst is selected to convert a heavy hydrocarbon feedstock to a product slate containing a commercially significant amount of a waxy intermediate fraction which will be upgraded to the original base stock. Exemplary commercial cracking catalysts generally contain a support consisting of alumina, silica, silica-alumina composites, silica-alumina-zirconia composites, silica-alumina-titania composites, acid treated clays, crystalline aluminosilicate zeolitic molecular sieves, such as zeolite A, faujasite, zeolite X, zeolite Y, and various combinations of the above. The hydrogenation/dehydrogenation components generally consist of a metal or metal compound of Group VIII or Group VIB of the periodic table of the elements. Metals and their compounds such as, for example, cobalt, nickel, molybdenum, tungsten, platinum, palladium and combinations thereof are known hydrogenation components of hydrocracking catalysts.
Separating
Separating is done by distillation. In one embodiment the lower boiling fraction and higher boiling fractions are separated by carefully controlled vacuum distillation having a tower top temperature, a tower bottom temperature, a tower top pressure and a tower bottom pressure that are selected to cleanly separate the hydrocarbons in the waxy intermediate fraction at a certain temperature. Various different types of vacuum distillation control systems may be employed, such as those taught in U.S. Pat. Nos. 3,365,386, 4,617092, or 4,894,145; in order to provide the highest yields of desired fractions and exact cut points.
In one embodiment of the process, the higher boiling fraction is a bottoms fraction front the separating step. The lower boiling fraction is a distillate side cut,
Hydroisomerization Dewaxing
In one embodiment, hydroisomerization dewaxing is used to dewax the lower boiling or higher boiling fractions. The hydroisomerization dewaxing is achieved by separately contacting the waxy intermediate fractions with a hydroisomerization dewaxing catalyst in an isomerization reactor under hydroisomerization dewaxing conditions. In one embodiment the hydroisomerization dewaxing catalyst comprises a shape selective intermediate pore size molecular sieve, a noble metal hydrogenation component, and a refractory oxide support. Examples of shape selective intermediate pore size molecular sieves include SAPO-11, SAPO-31, SAPO-41, SM-3, SM-7, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, SS2-32, SSZ-32X, metal modified SSZ-32X, offretite, ferrierite, and combinations thereof. SSZ-32X and metal modified SSZ-32X are described in U.S. Patent Publication US20080083657A1. SM-7 is described in U.S. patent application Ser. No. 12/181,652, filed Jul. 29, 2008,
The hydroisomerization dewaxing conditions include temperatures of 260° C. to about 413° C., a total pressure of 15 to 3000 psig, and a hydrogen to feed ratio from about 0.5 to about 30 MSCF/bbl. In some embodiments the hydrogen to feed ratio will be from about 1 to about 10 MSCF/bbl, or from about 4 to about 8 MSCF/bbl.
One example of a suitable upgrading process is described in U.S. Pat. No. 6,337,010, where the isomerization of the waxy intermediate feedstock is carried out at a lower total pressure than the hydrocracking operation.
Hydrofinishing
Optionally, the base stock produced by the dewaxing may be hydro-finished. The hydrofinishing may occur in one or more steps, either before or after the separating. The hydrofinishing is intended to improve the oxidation stability, UV stability, and appearance of the base stock by removing aromatics, olefins, color bodies, and solvents. A general description of hydrofinishing may be found in U.S. Pat. Nos. 3,852,207 and 4,673,487.
In one embodiment, the overall LHSV during hydrofinishing is about 0.25 to 2.0, or about 0.5 to 1.0. The hydrogen partial pressure can be greater than 200 psia, such as ranging from about 500 psia to about 2000 psia. Hydrogen recirculation rates can be greater than 50 SCF/Bbl, for example between 1000 and 5000 SCF/Bbl, Temperatures can range from about 149° C. to about 399° C. (300° F. to about 750° F.), such as from 232° C. to 316° C. (450° F. to 600° F.). Suitable hydrofinishing catalysts include noble metals from Group VIIIA (according to the 1975 rules of the International Union of Pure and Applied Chemistry), such as platinum or palladium on an alumina or siliceous matrix, and unsulfided Group VIIIA and Group VIB metals, 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 U.S. Pat. No. 4,157,294, and U.S. Pat. No. 3,904,513.
The non-noble metal (such as nickel-molybdenum and/or tungsten) catalyst contains at least about 0.5, such as about 1 to about 15 weight percent of nickel and/or cobalt determined as the corresponding oxides. The noble metal (such as platinum) catalyst contains in excess of 0.01 percent metal, such as between 0.1 and 1.0 percent metal. Combinations of noble metals may also be used, such as mixtures of platinum and palladium.
Base Stock by Process
We provide a base stock made by the process comprising hydrocracking, separating, and hydroisomerization dewaxing, as described previously. In general, the hydrocracking hydrocracks the heavy hydrocarbon feedstock in a hydrocracking zone. The operating conditions in the hydrocracking zone are selected to convert the heavy hydrocarbon feedstock to a product slate containing greater than 30 wt % of a waxy intermediate fraction. The waxy intermediate fraction is separated into a lower boiling fraction and a higher boiling fraction. The higher boiling traction is hydroisomerization dewaxed under conditions whereby the dewaxed higher boiling fraction is the base stock. The base stock has a first boiling range from 730 to 1000° F. (388 to 538° C.), a first VI from 105 to 130, a first CCS VIS at −25° C. from 2000 to 4500 mPa·s, and a ratio of a first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 from 0.15 to 0.40.
In one embodiment the base stock is made by a process additionally including dewaxing of the lower boiling fractions. The dewaxing conditions are selected such that a dewaxed lower boiling fraction is produced having an additional boiling range from 700 to 925° F. (371 to 496° C.), and additional VI from 105 to 115, and an additional Noack volatility less than 18 wt %.
In one embodiment the dewaxed lower boiling fraction has a ratio of the additional Noack volatility to an additional CCS VIS at −25° C. multiplied by 100 from 0.80 to 1.55. The higher boiling fraction may be a bottoms fraction from the separating step. The lower boiling fraction is a distillate side-cut fraction.
Base Oil Manufacturing Plant
We provide a base oil manufacturing plant, comprising a hydrocracking reactor, a vacuum distillation tower, and a hydroisomerization reactor. The base oil manufacturing plant produces a first base stock having a first boiling range from 730 to 1000° F. (388 to 538° C.), a first VI from 105 to 130, a first CCS VIS at −25° C. from 2000 to 4500 mPa·s, and a ratio of a first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 from 0.15 to 0.40. The base oil manufacturing plant may also produce an additional base stock having an additional boiling range from 700 to 925° F. (371 to 496° C.), an additional VI from 105 to 115, and an additional Noack volatility less than 18 wt %.
In one embodiment the operating conditions in the hydrocracking reactor are selected to convert a heavy hydrocarbon feedstock to a product slate containing greater than 30 wt % of a waxy intermediate fraction.
In one embodiment the vacuum distillation tower separates the waxy intermediate fraction from the hydrocracking reactor into a lower boiling fraction and a higher boiling fraction. The lower boiling fraction may be block dewaxed in the hydroisomerization dewaxing reactor to produce the first base stock. The higher boiling fraction may be block dewaxed in the hydroisomerization dewaxing reactor to produce the additional base stock. In some embodiments block dewaxing can give better yields and higher VI than bulk dewaxing a broader boiling feedstock.
In one embodiment the vacuum distillation tower follows the hydrocracking reactor.
In one embodiment the base oil manufacturing plant produces the additional base stock having a ratio of the additional Noack volatility to an additional CCS VIS at −25° C. from 0.80 to 1.55. Optionally, the first base stock has a ratio of the first Noack volatility to the first CCS VIS at −25° C. multiplied by 100 from 0.20 to 0.35.
In one embodiment, the first base stock and the additional base stock are both Group II base oils.
In one embodiment the hydroisomerization catalyst comprises a shape selective intermediate pore size molecular sieve. Examples of these are SAPO-11, SAPO-31, SAPO-41, SM-3, SM-7, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, SSZ-32, SSA-32X, metal modified SSZ-32X, offretite, ferrierite, and combinations thereof.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Furthermore, all ranges disclosed herein are inclusive of the endpoints and are independently combinable. Whenever a numerical range with a lower limit and an upper limit are disclosed, any number falling within the range is also specifically disclosed.
Any term, abbreviation or shorthand not defined is understood to have the ordinary meaning used by a person skilled in the art at the time the application is filed. The singular forms “a,” “an,” and “the,” include plural references unless expressly and unequivocally limited to one instance.
All of the publications, patents and patent applications cited in this application are herein incorporated by reference in their entirety to the same extent as if the disclosure of each individual publication, patent application or patent was specifically and individually indicated to be incorporated by reference in its entirety.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. Many modifications of the exemplary embodiments of the invention disclosed above will readily occur to those skilled in the art. Accordingly, the invention is to be construed as including all structure and methods that fall within the scope of the appended claims.
The following examples are provided to demonstrate particular embodiments of the present invention. It should be appreciated by those of skill in the art that the methods disclosed in the examples which follow merely represent exemplary embodiments of the present invention. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described and still obtain a like or similar result without departing from the spirit and scope of the present invention.
A few different samples of Chevron 170RLV base stock were made by hydrocracking and separating (by vacuum distillation) the waxy intermediate product from the hydrocracker into a heavy fraction and a light fraction. The hydrocracking conditions in the hydrocracking reactor were selected to convert vacuum gas oil to a product slate containing between 30 wt % and 40 wt % of a waxy intermediate fraction. After separating, the heavy and light fractions were block dewaxed using a hydroisomerization dewaxing catalyst comprising an Intermediate pore size magnesium metal modified SSZ-32X molecular sieve, a platinum hydrogenation metal, and an alumina support. The average properties of the Chevron 170RLV base stock and the Chevron 110RLV base stock that were produced are shown below, in Table I:
A few different samples of Chevron 110RLV2 base stock and Chevron 170RLV2 base stock were made by hydrocracking and separating (by vacuum distillation) the waxy intermediate product from the hydrocracker into a heavy fraction and a light fraction. The hydrocracking conditions in the hydrocracking reactor were increased in severity to make the bottoms product shown in Table II. After separating, the heavy and light fractions were block dewaxed using a hydroisomerization dewaxing catalyst comprising an intermediate pore size magnesium metal modified SSZ-32X molecular sieve, a platinum hydrogenation metal, and an alumina support. The average properties of the Chevron 110RLV2 base stock and Chevron 170RLV2 base stock that were produced are shown below, in Table II:
Others have manufactured base stocks having a boiling range of 730 to 1000° F. Three examples are Yubase 4, Yubase 6, and Shell XHVI 4.0. Some properties of these oils are shown below in Table III.
Ail three of these base stocks are expensive to manufacture and purchase. Yubase 6 and Shell XHVI 4.0 are Group III base oils. Yubase 4 has a ratio of Noack volatility to CCS VIS at −25° C. that is higher than is desired for optimal blending. If Yubase 4 were added to the chart in
Five different Group III base stocks were tested and found to have the properties as shown in Table IV. These different Group III base stocks are those that are often used in blending with Chevron 220R, or other Group II base oils, to meet the Noack volatility and CCS VIS at −25° C. requirements for multigrade engine oils.
Group III base oils are typically more expensive to manufacture and purchase than Group II base oils. Also, when they are used in engine oils they require additional testing to meet base oil interchange guidelines.
The chart shown in
Base oil requirements for 5W, 10W, and 15W engine oils were set by charting the points representing the CCS VIS at −25° C. and the Noack volatility of current commercial engine oils that meet all requirements. These were added to the chart as small squares and the general regions for 5W-XX, 10W-XX, and 15W-XX were labeled.
As can be seen by the chart shown in
Blending efficiency is demonstrated by the smaller area encompassed by the curves between the Group II base oils in
This application claims the benefit of non-provisional application Ser. No. 12/482,008, filed Jun. 6, 2009 and provisional application Ser. No. 61/101,676, filed Oct. 1, 2008, herein incorporated in their entireties. This application is a continuation-in-part of co-pending application of U.S. Ser. No. 12/482,008, filed Jun. 6, 2009. This application is related to co-filed patent application Ser. No. 12/481,827 (A 110 Neutral Base Oil with Improved Properties); Ser. No. 12/481,862 (A Process to Make a 110 Neutral Base Oil with Improved Properties); Ser. No. 12/481,903 (A Method for Predicting a Property of a Base Oil); and Ser. No. 12/482,082 (A Process to Manufacture a Base Stock and a Base Oil Manufacturing Plant), herein incorporated in their entireties.
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| Entry |
|---|
| PCT/US2009/046881 International Search Report mailed Mar. 9, 2010. |
| PCT/US2009/046881, 4 pages, international filing date Jun. 10, 2009. |
| Number | Date | Country | |
|---|---|---|---|
| 20130090272 A1 | Apr 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61101676 | Oct 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12482008 | Jun 2009 | US |
| Child | 13691470 | US |
