KR20070026837A - Process to prepare a lubricating base oil and its use - Google Patents

Abstract

Process to prepare an iso-paraffinic base oil having an improved seal swelling properties by subjecting a mixture of (i) a petroleum derived feed having a pour point below -5 ‹C, an aromatic content of between 0 and 20 wt% and a naphthenic compound content of between 15 and 90 wt% and (ii) a Fischer-Tropsch derived feed to a catalytic pour point reducing treatment and wherein the content of the petroleum derived feed (i) in the mixture is between 5 and 50 wt%. The invention is also directed to the use of the base oils thus obtained in gear oil and hydraulic oil application. ® KIPO & WIPO 2007

Description

Process for producing lubricating base oil and its use {PROCESS TO PREPARE A LUBRICATING BASE OIL AND ITS USE}

The present invention relates to a process for the preparation of iso-paraffinic base oils and to the use of said base oil products in hydraulic oil applications and crankcase applications.

WO-A-0246333 discloses two viscosity grade base oils by solvent dewaxing of a fraction having a T95% point above 621 ° C, and catalytic solvent dewaxing of a fraction having a T95% point below 621 ° C. The preparation method is described. The two fractions are Fischer-Tropsch derived fractions. Optionally the heavier or lower boiling fraction may also be slack wax, material distilled from crude oil, residual stock deasphalted from crude oil.

NL-C-1015035 describes a process for preparing base oils from Fischer-Tropsch derived feeds by performing a hydroisomerization step. The effluent of the hydroisomerization step is distilled off to obtain a boiling residue above 380 ° C. The residue is subjected to a catalytic dewaxing treatment using a catalyst containing platinum and ferrierite.

US-A-6294077 describes a catalytic dewaxing treatment wherein a catalyst consisting of ZSM-5 and platinum is used.

US-A-6025305 describes a method in which the Fischer-Tropsch wax feed is first hydroisomerized. The effluent of the hydroisomerization is then separated into fuel and lubricant. The patent does not describe the pour point drop treatment.

US-A-2002 / 0146358 describes a method for the hydroisomerization of a Fischer-Tropsch derived wax feed. The effluent of the hydroisomerization step is distilled off to obtain a bottom fraction comprising a compound having at least 20 carbon atoms. The bottom fraction can be subjected to catalytic dewaxing treatment.

WO-A-0157166 describes the use of highly paraffinic base oils obtained from Fischer-Tropsch waxes in motor engine lubricant formulations. Examples illustrate that such formulations will also consist of esters, which, in accordance with the specification of the invention, are added to impart additional desirable properties such as additive solubility.

A substantial problem with iso-paraffinic base oils produced by the methods described above is that such base oils are used, for example, in crankcase (gear oil) applications or as part of hydraulic oil where the oil contacts the seal. In that case, additional measurements must be taken to achieve sufficient swelling of the seal.

It is an object of the present invention to provide a process for producing a base oil from a Fischer-Tropsch derived feed in which the base oil has improved seal swelling properties.

This object is achieved by the following method. Catalytic Pour Point Drop Treatment of a Mixture of (i) a Petroleum-derived Feed with a Pour Point Below -5 ° C., an Aromatic Content of 0-20% by Weight and a Naphthenic Compound Content of 15-90% by Weight; The content of the petroleum derived feed (i) in the mixture is 5 to 50% by weight), wherein the iso-paraffinic base oil having improved seal swelling properties.

Applicants have found that by catalytic dewaxing of the mixture as described above, iso-paraffinic base oils with improved seal swelling properties are obtained.

The pour point of the petroleum derived feed is below -5 ° C, preferably below -10 ° C, more preferably below -15 ° C. The petroleum derived feed has an aromatic content of 0 to 20% by weight and a naphthenic compound content of 15 to 90% by weight. The content can be measured by well known techniques such as those described in Example 1 herein. The saturate content of the petroleum derived feed is preferably greater than 90% by weight, more preferably greater than 95% by weight, even more preferably greater than 98% by weight and most preferably greater than 99% by weight. The sulfur content is preferably less than 0.03% by weight, more preferably less than 0.01% by weight, even more preferably less than 0.001% by weight. An advantage of using such a typical dewaxed oil with such low sulfur, nitrogen and high saturates is that no additional hydrofinishing is required after the pour point dropping step of the process of the invention. Advantageously, catalytic dewaxing will then not have to be carried out at the higher pressures required for subsequent hydrofinishing. In contrast the process of the invention can then be carried out at even more preferred lower hydrogen pressures in the range of 15 to 70 bar.

Petroleum derived feeds preferably employ a hydroprocessing step to reduce the aromatic, sulfur and nitrogen content of these fractions and to improve some desirable properties such as viscosity index. The hydroprocessing step may optionally be a hydrocracking step followed by a hydroprocessing. Low pour point is preferably achieved by solvent or more preferably by catalytic dewaxing step. This process is carried out, for example, when the base oil is prepared from petroleum derived vacuum distilled material or deasphalted oil.

Very interesting petroleum derived feeds are the so-called API II or III base oils, for example produced by the hydrogenation process. Suitable hydrogenation processes for producing such base oils are described, for example, in WO-A-2004053029, WO-A-9801515, US-A-5976354 and WO-A-2004044097. Suitably the base oil is prepared from the bottom fraction of the fuel hydrocracking plant. By fuel hydrocracking plant in the context of the present invention is meant a hydrocracking plant process whose main products are naphtha, kerosene and gas oil. In the hydrotreatment-hydrocracker process, the conversion expressed in weight percent of the fraction in the feed to the hydrotreatment-hydrocracker, boiling above 370 ° C., is converted to a boiling product below 370 ° C. More than 50% by weight. Examples of possible fuel hydrocracking plant processes that can yield bottom fractions that can be dewaxed to yield the desired base oil are described above in EP-A-699225, EP-A-649896, WO-A. -9718278, EP-A-705321, EP-A-994173 and US-A-4851109.

Preferably the fuel hydrocracking plant is operated in two stages, consisting of a first hydrotreating stage followed by a hydrocracking stage. In the hydrotreating step, nitrogen and sulfur are removed and the aromatics are saturated with naphthenes.

Omitting this hydrofinishing step is particularly possible when the mineral derived waxed oil itself is produced by a process comprising a hydrofinishing step, preferably carried out at hydrogen pressures above 100 bar. Examples of such hydrofinishing processes are, for example, those described below.

The oil is preferably prepared from a vacuum distilled material or deasphalted vacuum residue of the mineral crude feedstock or starting from a waxy feed such as, for example, slack wax, wherein the process is preferred for sulfur and polar compounds. Hydroprocessing step to reduce to a range. The viscosity index is preferably 80 to 150 and good results have been achieved with oils having a viscosity index of 80 to 120.

Preferably the T10 wt% recovery point of the oil is 200 to 450 ° C, more preferably 300 to 420 ° C, and the T90 wt% recovery point is 300 to 550 ° C, more preferably 400 to 550 ° C. By using this wide boiling oil, the iso- of the resulting base oil is both lower and lower viscosity grades with kinematic viscosity at 100 ° C. up to 2 cSt, including higher viscosity grades with 15 kSt kinematic viscosity at 100 ° C. It has been found that it is possible to reduce the paraffin content.

Dewaxed oils are described, for example, in Lubricant Base Oil and Wax Processing, Avilino Sequeira, Jr, Marcel Dekker, Inc. New York, 1994, page 119-150, which may be obtained by the well-known method described in Chapter 6. Preferred wide boiling oils can be prepared by mixing base oils of various viscosity grades, preferably of API II or III. Examples of processes for producing oils that can be used in the process are described in EP-A-0909304, EP-A-1137741, EP-A-1392799, EP-A-1311651. Examples of suitable dewaxed oils are, for example, XHVI-4, XHVI-5.2 and XHVI-8 base oil products from Shell or Visom base oil grades from ExxonMobil and mixtures thereof. Possible commercial processes for producing base oils for use in the present invention are said to contain base oils containing less than 1% by weight of aromatics, less than 1 ppm of sulfur, more than 120 viscosity index, and less than pour point −15 ° C. ExxonMobil's MSDW ™ / MAXSAT ™ type of process.

More preferred dewaxed oils meeting the above specifications are those obtained when the bottom fraction of the fuel hydrocracking plant undergoes a catalytic dewaxing followed by a hydrofinishing step, as described above. Examples of documents describing this route are WO-A-9802502, WO-A-0027950, WO-A-9500604, EP-A-0883664 and EP-A-0863963.

An additional advantage of the addition of the dewaxed oil as described above for the pour point drop treatment of the process of the invention is that any unwanted compounds (e.g., residual waxes, polar substances, sulfur or nitrogen) in the oil are It can be further reduced in the above treatment. Another advantage is that the boiling range nature, pour point and / or volatility of the final base oil can be adjusted in a simple manner by controlling the dewaxing state of the product obtained in the dewaxing treatment and any further distillation. This is advantageous because it is possible to use a wide variety of dewaxed oils in the process according to the invention. For example, if these oils are blended after dewaxing and final distillation of 100% Fischer-Tropsch derived feeds, the more stringent property properties for mineral-derived admixtures, such as, for example, Noack volatility and viscosity, Will be needed. The process according to the invention therefore makes it possible to use a variety of dewaxed oils having the above properties and to obtain base oils with the desired paraffin content and other desirable base oil properties, in particular Noack volatility and pour point.

The Fischer-Tropsch derived feed is preferably a hydroisomerized Fischer-Tropsch wax. Such feeds can be obtained by well known methods, for example by the so-called commercial Sasol process, Shell Distillate Synthesis Process or ExxonMobil "AGC-21" process. These and other processes are described in more detail in, for example, EP-A-776959, EP-A-668342, US-A-4943672, US-A-5059299, WO-A-9934917 and WO-A-9920720. The method will generally comprise a Fischer-Tropsch synthesis and hydroisomerization step as described in this patent. This process for preparing a hydroisomerized Fischer-Tropsch feed for use as a feed in the present process will include the following steps:

(a) hydrocracking / hydroisomerize the Fischer-Tropsch product,

(b) separating the product of step (a) into one or more gas oil fractions and the high boiling Fischer-Tropsch derived feed according to the invention.

Preferably the Fischer-Tropsch product used as feed in step (a) has a weight ratio of at least 60 carbon atoms and at least 30 carbon atoms in the Fischer-Tropsch product and at least 30% by weight in the Fischer-Tropsch product The compound is a product having 30 or more carbon atoms.

Applicants have found that by carrying out the hydrocracking / hydroisomerization step with a relatively heavy feedstock, a higher yield of gas oil as calculated for the feed to step (a) can be obtained. A further advantage is that both fuels, such as gas oil and Fischer-Tropsch derived feeds, are produced in one hydrocracking / hydroisomerization process step. In a preferred embodiment of the invention, the boiling fraction above the Fischer-Tropsch derived feed is isolated in step (b) and recycled to step (a).

Another advantage is to prepare a Fischer-Tropsch derived feed that already has a certain amount of cyclo-paraffins by performing step (a) on a relatively heavy feed.

The relatively heavy Fischer-Tropsch product used in step (a) more preferably has at least 50% by weight, even more preferably at least 55% by weight of compounds having at least 30 carbon atoms. Further, the weight ratio of the compound having 60 or more carbon atoms and the compound having 30 or more carbon atoms of the Fischer-Tropsch product is more preferably 0.4 or more, even more preferably 0.50 or more. Preferably the Fischer-Tropsch product has a C ₂₀₊ having an ASF-alpha 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. Fractions.

The initial boiling point of the Fischer-Tropsch product may range up to 400 ° C., but is preferably below 200 ° C. Preferably any compound having up to 4 carbon atoms and any compound having a boiling point in the above range is separated from the Fischer-Tropsch synthesis product before the Fischer-Tropsch synthesis product is used in step (a). Fischer-Tropsch products as detailed above are Fischer-Tropsch products that have not been subjected to the hydroconversion step as defined in accordance with the present invention. Therefore, the content of unbranched compound in the Fischer-Tropsch product will be greater than 80% by weight. In addition to the Fischer-Tropsch product, other fractions may also be further processed in step (a). Possible other fractions are suitably any high-boiling fractions obtained in step (b) or off-spec base oils as part of said fractions and / or obtained in the pour point drop treatment of the process of the invention. Fractions.

This Fischer-Tropsch product can be obtained by any process, which yields a relatively heavy Fischer-Tropsch product as described above. Not all Fischer-Tropsch processes yield this heavy product. Examples of suitable Fischer-Tropsch processes are described in WO-A-9934917 and AU-A-698392. This process can yield a Fischer-Tropsch product as described above.

The Fischer-Tropsch product will contain little or no sulfur and nitrogen containing compounds. This is typical for products derived from Fischer-Tropsch reactions using synthetic gas containing few impurities. Sulfur and nitrogen levels will generally be below the detection limit, with current sulfur 2 ppm and nitrogen 1 ppm, respectively.

The Fischer-Tropsch product may optionally apply a mild hydrotreatment step to remove any oxygenates and saturates and any olefinic compounds present in the reaction product of the Fischer-Tropsch reaction. This hydrotreatment is described in EP-B-668342. The lightness of the hydrotreatment step is preferably expressed as having a conversion of less than 20% by weight, more preferably less than 10% by weight. The conversion here is defined as the weight percentage of the boiling feed above 370 ° C., which reacts to the boiling fraction below 370 ° C. After this mild hydrotreatment, low-boiling compounds with up to 4 carbon atoms and other compounds boiling in the range will preferably be removed from the effluent before being used in step (a).

The hydrocracking / hydroisomerization reaction of step (a) is preferably carried out in the presence of hydrogen and a catalyst, wherein the catalyst can be selected from catalysts known to those skilled in the art which are suitable for the present reaction which will be described in more detail below in part. . The catalyst can generally be any catalyst known in the art suitable for the isomerization of paraffinic molecules. In general, suitable hydroconversion catalysts are those comprising a hydrogenation component supported on a refractory oxide carrier (such as amorphous silica-alumina, alumina, alumina fluoride, molecular sieve (zeolite) or a mixture of two or more thereof). One type of preferred catalyst applied in the hydroconversion step according to the invention is a hydroconversion catalyst comprising platinum and / or palladium as the hydrogenation component. Even more preferred hydroconversion catalysts include platinum and palladium supported on amorphous silica-alumina (ASA) carriers. Platinum and / or palladium are calculated as elements and are present in an amount of suitably 0.1 to 5.0% by weight and more suitably 0.2 to 2.0% by weight relative to the total weight of the carrier. If both are present, the weight ratio of platinum to palladium (calculated as element) may vary widely, but suitably ranges from 0.05 to 10, more suitably from 0.1 to 5. Examples of suitable noble metals on ASA catalysts are described, for example, in WO-A-9410264 and EP-A-0582347. Other suitable precious metal-based catalysts such as platinum on fluorinated alumina carriers are described, for example, in US-A-5059299 and WO-A-9220759. Preferably such catalysts do not comprise molecular sieves, and more preferably such catalysts do not comprise zeolite beta.

A second type of suitable hydroconversion catalyst is those comprising at least one Group VIB metal, preferably tungsten and / or molybdenum, and at least one Group VIII non-noble metal, preferably nickel and / or cobalt as hydrogenation components. to be. Typically the two metals are present as oxides, sulfides or combinations thereof. Group VIB metals are calculated as elements and are present in an amount of 1 to 35% by weight, more preferably 5 to 30% by weight, relative to the total weight of the carrier. Group VIII non-noble metals are calculated as elements and are present in an amount of 1 to 25% by weight, preferably 2 to 15% by weight, relative to the total weight of the carrier. Hydrogen conversion catalysts of this type that have been found to be particularly suitable are catalysts comprising nickel and tungsten supported on alumina fluoride.

Preferred catalysts that can be used in the non-sulfide form include group VIII non-noble metals (eg iron, nickel) supported on an acidic support in combination with group IB metals (eg copper). The surface area of the catalyst is in the range of 200 to 500 m 2 / g, preferably 0.35 to 0.80 ml / g, and the bulk density is about 0.5 to 1.0 g / ml as measured by water absorption. The catalyst support is preferably amorphous silica-alumina in which the alumina is present in an amount of less than about 30% by weight, preferably 5 to 30% by weight, more preferably 10 to 20% by weight. In addition, the support may contain small amounts (eg 20 to 30% by weight) of binders such as alumina, silica, Group IVA metal oxides, and various types of clays, magnesia and the like, preferably alumina.

The preparation of amorphous silica-alumina microspheres is described by Ryland, Lloyd B., Tamele, M. W., and Wilson, J. N., Cracking Catalysts, Catalysis: volume VII, Ed. Paul H. Emmett, Reinhold Publishing Corporation, New York, 1960, pp. 5-9].

The catalyst is prepared by co-impregnating a metal from solution on a support, drying at 100 to 150 ° C., and calcining at 200 to 550 ° C. air. Group VIII metals are present in an amount of less than about 15% by weight, preferably 1 to 12% by weight, while Group IB metals are typically 1: 2 to about 1:20 for smaller amounts, for example Group VIII metals. Present in an amount by weight.

Typical catalysts are shown below:

Ni, wt.% 2.5-3.5

Cu, weight% 0.25-0.35

Al ₂ O ₃ -SiO ₂ % by weight 65-75

Al ₂ O ₃ (Binder) Weight% 25-30

Surface area 290-325 ㎡ / g

Pore Volume (Hg) 0.35-0.45 ml / g

Bulk Density 0.58-0.68 g / ml

Another class of suitable hydroconversion catalysts are those based on zeolite-based materials, suitably comprising at least one Group VIII metal component, preferably Pt and / or Pd, as the hydrogenation component. Suitable zeolitic materials are then zeolite Y, Ultra Stable Y, ZSM-5, ZSM-12, ZSM-22, ZSM-23, ZSM-48, ZSM-35, SSZ-32, ferrierite, zeolite beta, Mordenite and silica-aluminophosphates such as SAPO-11 and SAPO-31 or combinations of catalysts comprising such molecular sieves. Examples of suitable hydroisomerization catalysts and methods are described, for example, in WO-A-9201657, WO-A-0107538 or US-A-20040065581.

The way in which step (b) can be omitted is described, for example, in US-A-20040065581 and EP-A-1029029. The publication discloses that the feed is contacted with platinum / zeolite beta and then the effluent is directly contacted with platinum / ZSM-48 or platinum / ZSM-23 dewaxing catalysts to form a base oil of narrow boiling Fischer-Tropsch derived wax. The conversion of is described. The petroleum derived feed in this line-up can advantageously be added prior to contact with the platinum / ZSM-48 or platinum / ZSM-23 catalysts according to the invention.

In step (a) the feed is contacted with hydrogen in the presence of a catalyst at elevated temperature and elevated pressure. The temperature will typically range from 175 to 380 ° C., preferably above 250 ° C., more preferably 300 to 370 ° C. The pressure will typically be in the range of 10 to 250 bar, preferably 20 to 80 bar. Hydrogen can be supplied at a gas hourly space velocity of 100 to 10000 Nl / l / hr, preferably 500 to 5000 Nl / l / hr. The hydrocarbon feed may be provided at a space velocity per weight hour of 0.1 to 5 kg / l / hr, preferably more than 0.5 kg / l / hr, more preferably less than 2 kg / l / hr. The ratio of hydrogen to hydrocarbon feed ranges from 100 to 5000 Nl / kg, preferably from 250 to 2500 Nl / kg.

The degree of conversion in step (a), defined as the weight percentage of boiling feed above 370 ° C. per reactant to the boiling fraction below 370 ° C., is at least 20% by weight, preferably at least 25% by weight, but preferably Is 80% by weight or less, more preferably 70% by weight or less. The feed as used in the above definition is the total hydrocarbon feed fed to step (a), and therefore also any recycle of the high boiling fraction obtained in step (b).

In step (b) the product of step (a) is separated into at least one gas oil fraction and a Fischer-Tropsch derived feed, preferably having a T10 wt% boiling point of 200 to 450 ° C. When the high boiling fraction is separated from the Fischer-Tropsch feed, the T90 weight percent of the feed is preferably 300 ° C., preferably 430-550 ° C. Separation is preferably carried out by first distillation at approximately atmospheric conditions, preferably at a pressure of 1.2 to 2 bara, wherein gaseous oil products and low boiling fractions such as naphtha and kerosene fractions are obtained from the product of step (a). From high boiling fractions. Suitably the high boiling fraction at least 95% by weight boiling above 370 ° C. may be further separated in a vacuum distillation step in which the high boiling fraction is separated. Vacuum distillation is suitably carried out at a pressure of 0.001 to 0.05 bara.

The vacuum distillation of step (b) is preferably operated so that the preferred Fischer Tropsch derived feed is boiled and has a kinematic viscosity in a certain range, related to the base oil end product (s) properties. The kinematic viscosity at 100 ° C. of the Fischer Tropsch derived feed is preferably 3 to 10 cSt.

The mixture of petroleum derived and Fischer-Tropsch derived feeds will suitably have a viscosity corresponding to the desired viscosity of the base oil product. Preferably the kinematic viscosity at 100 ° C. of the mixture is 3 to 10 cSt. Suitable distillate fractions have a T10 wt% boiling point of 200 to 450 ° C, preferably 300 to 420 ° C and a T90 wt% boiling point of 300 to 550 ° C, preferably 400 to 550 ° C. The fraction of the petroleum derived feed in the mixture is preferably more than 5% by weight, more preferably more than 10% by weight, preferably less than 50% by weight, more preferably less than 30% by weight, even more preferably 25% by weight. Is less than. The actual content of the petroleum-derived feed in the mixture will of course depend on the paraffin content in the feed. The mixture will preferably contain less than 50 ppm sulfur and / or less than 10 ppm nitrogen.

In a preferred embodiment the Fischer-Tropsch derived feed is partially dewaxed to a pour point close to the pour point of the petroleum derived feed before mixing the two feeds for further dewaxing to the target pour point. An advantage of this embodiment is that the conversion of the petroleum feed to distillate or lighter product is therefore minimized. By "close to the pour point" is meant that the difference between the pour point of the Fischer-Tropsch derived feed and the pour point of the petroleum derived feed is less than 40 ° C, preferably less than 20 ° C. Pour point is the pour point of the entire feed to step (b). The drop in the pour point of the Fischer-Tropsch derived feed is suitably carried out by the catalytic dewaxing process described herein. More preferably pre-waxing is carried out in the upper layer of the catalytic dewaxing reactor and the combined feed is dewaxed to its target pour point in the lower layer of the dewaxing reactor, ie the further downstream layer. The petroleum-derived feed is added at the intermediate stage in the conversion. The volume ratio of the dewaxing catalyst in the upper catalyst layer and the lower catalyst layer is from 1: 9 to 9: 1, more preferably 3: 1 to 5: 1.

Catalytic pour point treatment is understood to be any process that lowers the pour point of the base oil to above 10 ° C, preferably above 20 ° C, more preferably above 25 ° C.

The catalytic dewaxing or pour point drop process can be carried out by any process that lowers the pour point of the mixture in the presence of catalyst and hydrogen as described above. Suitable dewaxing catalysts are heterogeneous catalysts comprising in combination with molecular sieves and optionally metals having a hydrogenation action, such as Group VIII metals. Molecular sieves, and more suitably medium pore size zeolites, exhibit good catalytic ability to lower the pour point of the distillate base oil precursor fraction under catalytic dewaxing conditions. Preferably the medium pore size zeolite has a pore diameter of 0.35 to 0.8 nm. Suitable medium pore size zeolites are mordenite, ZSM-5, ZSM-12, ZSM-22, ZSM-23, SSZ-32, ZSM-35 and ZSM-48. Another preferred group of molecular sieves is SAPO-11, the most preferred silica-alumina phosphate (SAPO) material, as described, for example, in US-A-4859311. ZSM-5 can optionally be used in its HZSM-5 form in the absence of any Group VIII metal. Other molecular sieves are preferably used in combination with the added Group VIII metal. Suitable Group VIII metals are nickel, cobalt, platinum and palladium. Examples of possible combinations are Ni / ZSM-5, Pt / ZSM-23, Pd / ZSM-23, Pt / ZSM-48 and Pt / SAPO-11. Further details and examples of suitable molecular sieves and dewaxing conditions are described, for example, in WO-A-9718278, US-A-5053373, US-A-5252527 and US-A-4574043.

The dewaxing catalyst suitably also includes 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 of the montmorillonite and kaolin series, for example. The binder is preferably a porous binder material, for example alumina, silica-alumina, silica-magnesia, silica-zirconia, silica-toria, silica-berilia, silica-titania, as well as ternary compositions, for example Refractory oxides of silica-alumina-toria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. More preferably a low acid refractory oxide binder material is used which is essentially alumina free. Examples of such binder materials are silica, zirconia, titanium dioxide, germanium dioxide, boria and mixtures of two or more of which examples are listed above. Most preferred binder is silica.

A preferred series of dewaxing catalysts include intermediate zeolite microcrystals as described above and low acid refractory oxide binder materials essentially free of alumina as described above, wherein the aluminosilicate zeolite microcrystals are dealuminated on the surface. The surface of the aluminosilicate zeolite microcrystals was modified. Preferred dealumination treatments are by contacting the extrudate of binder and zeolite with an aqueous solution of fluorosilicate salts, as described, for example, in US-A-5157191 or WO-A-2000029511. Examples of suitable dewaxing catalysts as described above are, for example, silica bound and dealuminated Pt / ZSM-5, silica bonded and deaerated as described in WO-A-200029511 and EP-B-832171. Aluminized Pt / ZSM-23, silica bound and dealuminated Pt / ZSM-12, silica bound and dealuminated Pt / ZSM-22.

Catalytic dewaxing conditions are known in the art and typically range from 200 to 500 ° C., suitably from 250 to 400 ° C., from 10 to 200 bar of hydrogen pressure, preferably from 40 to 70 bar. The weight hourly space velocity (WHSV) is in the range of 0.1 to 10 kg (kg / l / hr) of oil per liter of catalyst per hour, suitably 0.2 to 5 kg / l / hr, more suitably 0.5 to 3 kg / l / hr and hydrogen to oil ratios range from 100 to 2,000 liters of hydrogen per liter of oil. In the catalytic dewaxing step, it is possible to produce base oils with different pour point properties, suitably varying below -60 to -10 ° C by modifying the temperature to 315 to 375 ° C at a pressure of 40 to 70 bar. .

The precious metal guard bed can optionally be placed immediately upstream of the dewaxing step, for example as a separate catalyst bed in the dewaxing reactor. This protective layer is advantageous for removing any residual sulfur and especially nitrogen compounds present in the feed for the dewaxing process of the present invention. This protective layer is suitably used when the bottom fraction of the fuel hydrocracking plant process is used as a petroleum derived feed. Examples of such methods are described in WO-A-9802503, which is incorporated herein by reference.

The low boiling compound formed during the treatment after the pour point drop treatment is suitably removed, preferably by distillation, optionally with an initial sewage step.

The effluent of the pour point drop treatment may suitably be applied to the hydrogenation treatment. Hydrogenation can be carried out to the entire effluent or to a particular base oil grade after fractionation described above. This may be necessary to reduce the content of aromatic compounds in the reduced pour point product, preferably to a value of less than 1% by weight. This hydrogenation is also called hydrofinishing step. The step is suitably carried out at a temperature of 180 to 380 ° C., at a total pressure of 10 to 250 bar, preferably more than 100 bar, more preferably 120 to 250 bar. WHSV (space velocity per weight hour) ranges from 0.3 to 2 kg (kg / l / h) of oil per liter of catalyst per hour. Preferably the hydrogenation is carried out in the same reactor as the catalytic dewaxing reactor. In this reactor, the dewaxing catalyst and hydrogenation catalyst layers will be placed in layers stacked on top of each other.

The hydrogenation catalyst is suitably a supported catalyst comprising a dispersed Group VIII metal. Possible Group VIII metals are cobalt, nickel, palladium and platinum. Cobalt and nickel containing catalysts may also include Group VIB metals, suitably molybdenum and tungsten. Suitable carrier or support materials are low acid amorphous refractory oxides. Examples of suitable amorphous refractory oxides include inorganic oxides such as alumina, silica, titania, zirconia, boria, silica-alumina, fluorinated alumina, fluorinated silica-alumina and mixtures of two or more thereof.

Examples of suitable hydrogenation catalysts include nickel-molybdenum containing catalysts such as KF-847 and KF-8010 (AKZO Nobel) M-8-24 and M-8-25 (BASF), and C-424, DN-190, HDS -3 and HDS-4 (Criterion); Nickel-tungsten containing catalysts such as NI-4342 and NI-4352 (Engelhard) and C-454 (Criterion); Cobalt-molybdenum containing catalysts such as KF-330 (AKZO-Nobel), HDS-22 (Criterion) and HPC-601 (Engelhard). Preferably platinum containing, more preferably platinum and palladium containing catalysts are used. Preferred support for the palladium and / or platinum containing catalyst is amorphous silica-alumina. Examples of suitable silica-alumina carriers are described in WO-A-9410263. Preferred catalysts include alloys of palladium and platinum supported on amorphous silica-alumina carriers, preferably taking the catalyst C-624 from Criterion Catalyst Company (Houston, TX).

After performing the catalytic pour point treatment or after any hydrofinishing step, hydrogen is suitably separated from the dewaxing / hydrofinished effluent, contacted with means for removing hydrogen sulfide and recycled to the catalytic pour point treatment. Let's do it. Such means may be amine washing of the hydrogen recycle stream. If the content of hydrogen sulfide in the recycle stream is expected to be low, for example less than 100 ppm, or even less than 20 ppm, it would be desirable to contact the stream with a suitable adsorbent. Examples of suitable heterosorbents include one or more of metals or oxides of metals (metal (s) is selected from Fe, Ni, Co, Ag, Sn, Re, Mo, Cu, Pt, Pd and Zn). In a preferred embodiment, the metal is one or more of Fe, Ni, Co, Cu, and Zn. In a more preferred embodiment, the adsorbent is zinc oxide. The adsorbent can be supported on the inorganic support material, for example, to increase the surface area, pore volume, and pore diameter. Suitable support materials include, but are not limited to, alumina, silica, zirconia, carbon, silicon carbide, diatomaceous earth, amorphous and crystalline silica-alumina, silica-magnesia, aluminophosphate, boria, titania, and zinc oxide. One or more inorganic refractory support materials. Preferred support materials include alumina, zirconia, and silica. The metal (s) or metal oxide (s) can be loaded onto the support by conventional techniques known in the art. Non-limiting examples of recyclable sulfur sorbents based on suitable supported metals and metal oxides include: Co / Al ₂ O ₃ ; Co / SiO ₂ ; Co / TiO ₂ ; Co / ZrO ₂ ; Ni / Al ₂ O ₃ ; Ni / SiO ₂ ; Ni / ZrO ₂ ; Cu / Al ₂ O ₃ ; Cu / SiO ₂ ; Cu / ZrO ₂ ; Fe / Al ₂ O ₃ ; Fe / SiO ₂ ; Fe / ZrO ₂ ; Co / Cu / Al ₂ O ₃ ; Co / Cu / SiO ₂ ; Ni / Cu / SiO ₂ ; Ni / Cu / ZrO ₂ ; Co / Pt / Al ₂ O ₃ ; Co / Pd / SiO ₂ ; Co / Sn / Al ₂ O ₃ ; Ni / Sn / SiO ₂ ; Zn / Al ₂ O ₃ , ZnO / SiO ₂ , Co / ZnO; Mo / ZnO; Ni / ZnO; Co / Mo / ZnO; Ni / Mo / ZnO; Pt / ZnO; Pd / ZnO; Pt / Pd / ZnO is included, but is not necessarily limited thereto. The adsorbent may also be used as bulk metal or as bulk metal oxide, including but not limited to finely divided skeleton metals, including Raney metals, heavy metals, Rieke metals, and metal sponges. The temperature and pressure conditions during the contact are preferably within a specific range for the catalytic pour point drop.

One or more base oil grades may be isolated by fractionation from the effluent of the pour point drop treatment and any hydrogenation treatment. Advantageously a base oil product having a kinematic viscosity at 100 ° C. of 2 to 10 cSt, a volatility of 8 to 11% (according to CEC L40 T87) and a pour point of −20 to −60 ° C. (according to ASTM D 97) Can be obtained.

The content of paraffin in the base oil to be produced is preferably 75 to 95% by weight, more preferably less than 90% by weight, more preferably more than 80% by weight.

The base oils described above may suitably find use as base oils for motor vehicle transmission fluid (ATF), motor engine oils, electronic oils or transformer oils and refrigerator oils. Lubricant formulations such as motor engine oils of 0W-x and 5W-x properties (where x is 20, 30, 40, 50 or 60) according to SAE J-300 viscosity classification are advantageously used Can be prepared.

It has been found that lubricant formulations can be prepared with base oils obtainable by the process of the invention without the need to add high amounts of additional ester or aromatic co-base oils. Preferably less than 15% by weight, more preferably less than 10% by weight of such ester or aromatic co-base oils are present in this formulation.

The Fischer-Tropsch process is often performed at a location remote from the end user of the base oil. It has also been found that for certain applications end users do not necessarily have to use base oils with high content of paraffin prepared by prior art processes operating on 100% Fischer-Tropsch derived feeds. For this application miscation with mineral derived base oils containing less paraffin will have to occur to reduce the paraffin content. However, not always suitable mineral admixtures are found near the end user. As explained above, these admixture components need to have suitable volatility and viscosity to obtain the desired admixtures. The present invention solves this problem by preparing the lower paraffinic base oil, which is desired at a remote location, to have a pour point and viscosity index in addition to specific volatility and viscosity from petroleum derived feeds that do not need to meet all stringent quality properties. Thus, the process is obtained, for example, from petroleum-derived feeds from one location, and the base oil obtained by this process is sold at many different locations. In a preferred embodiment, the petroleum-derived feed is transported to a remote location from another location and a portion of the base oil produced by the process is delivered to said other location using the same vessel. This is therefore advantageous because an efficient use of the conveying force between the two positions is achieved.

The base oils obtained according to this method have an improved seal expansion capability compared to base oils prepared exclusively from Fischer-Tropsch derived feeds. This makes the base oil particularly applicable for use in automotive transmission oils. Automotive transmission gear oils are well known applications and are described, for example, in Lubricants and related products, Dieter Klamann, Verlag Chemie, Basel, 1984 ISBN 3-527-26022-6, Chapter 11.6, pages 279-286. Preferred gear oil applications are passenger car transmission applications and light and medium vehicle diesel transmission applications. Automotive transmission applications, both manual and automatic, vary, as well as belt oil and toroidal continuous variable transmissions, which are preferred transmission oil applications. Another preferred use of the base oil obtained by the process is as part of the hydraulic oil composition. Hydraulic oils are well known applications and are described, for example, in Lubricants and related products, Dieter Klamann, Verlag Chemie, Basel, 1984 ISBN 3-527-26022-6, Chapter 11.9, pages 307-330. Preferred uses of base oils are hydraulics requiring a high viscosity index as described in Lubricants and related products, Dieter Klamann, Verlag Chemie, Basel, 1984 ISBN 3-527-26022-6, Chapter 11.9.5, page 320. Oil. The content of the improved base oils in this application and any additives used in such compositions can be easily deduced based on the knowledge of those skilled in the art and on general knowledge as described, for example, in the general references mentioned in this paragraph.

Example  One

12.7 parts by weight of a broad boiling, dewaxed, hydrofinished oil having the properties listed in Table 3 was mixed with 87.3 parts by weight of Shell MDS waxy Raffinate having the properties listed in Table 1. Extensive boiling dewaxed and hydrofinished oils were prepared by catalytic dewaxing of the bottom fraction of the fuel hydrocracking plant followed by hydrofinishing step on the dewaxed effluent. The hydrocracker was fed vacuum distilled material of mineral crude feed.

This blend of API II group oils was mixed with Shell MDS waxy raffinate (No. 1) having the properties listed in Table 1.

Feed Wide range of boiled mineral dewaxed and hydrofinished oils Shell MDS Wax Raffinate 1 Density (D20 / 4) 0.847 0.784 Drop point (℃) -24 45 Nitrogen (ppmw) <1 <1 Sulfur (ppmw) 8 <2 Kinematic viscosity at 100 ℃ 4.679 5.098 Initial boiling point (IBP) ℃ 137 362 IBP-390 ℃ (wt%) 20.6 2.3 390-520 ℃ (wt%) 67.9 88.4 520 ℃-FBP (wt%) 11.5 9.3 Final boiling point (FBP) ℃ 600 573 Wax Content (wt%) No wax 27.1 (*)

(*) Measured after solvent dewaxing at -27 ° C.

The blend was contacted with a dewaxing catalyst consisting of 0.7 wt% platinum, 25 wt% ZSM-12 and silica binder. Dewaxing conditions were 40 bar hydrogen, WHSV = 1 kg / l / h, and the hydrogen gas ratio was 700 Nl / kg feed. The experiment was carried out at two different reaction temperatures, 317 ° C.

Boiling base oil at 400 to 470 ° C. from the effluent of the dewaxing step was isolated from low and high boiling products. The yield of this fraction was 40% by weight relative to the blended feed. The pour point was -30 ° C, the kinematic viscosity at 100 ° C was 4,059 cSt, and the viscosity index was 129. The composition of the fractions was analyzed using the following technique.

The cyclo-paraffin (naphthenic compound) content in the present mixture of cyclo-, ordinary and iso-paraffins was measured by the following method. Any other method that produces the same result can also be used. The base oil sample is first separated into polar (aromatic) and nonpolar (saturated) phase using quantitative high performance liquid chromatography (HPLC) method IP368 / 01 (where pentane is used as the fluidized bed instead of hexane). It was. The saturates and aromatic fractions are then subjected to a field desorption / field ionization (FD / FI) interface, where FI ("soft" ionization technology) is used to quantify the hydrocarbon type depending on the carbon number and hydrogen deficiency of this particular base oil fraction. Analyze using a Finnigan MAT90 mass spectrometer equipped. Instrument conditions for achieving this soft ionization technique are source temperature 30 ° C., extraction voltage 5 kV, emitter current 5 mA and probe temperature ramp 40 ° C. to 400 ° C. (20 ° C./min).

The type classification of compounds in mass spectrometry is measured by the characteristic ions that are formed, usually by the "z number". This is given by the general formula: C n H ₂ n + z for all hydrocarbon species. Since the saturate phase is analyzed separately from the aromatic phase, it is possible to determine the content of different (cyclo) -paraffins having the same stoichiometry. The results of the mass spectrometers were obtained from commercial software (Poly 32; sold by Sierra Analytics LLC, 3453 Dragoo Park Drive, Modesto, Calif. GA95350 USA).

For the base oil fraction boiling at 400-470 ° C. as obtained above, the composition was measured using the above technique. The base oil consisted of 83 wt% paraffin, 16 wt% naphthenic compound and 1 wt% polar compound.

Example  2

30 ml of the base oil obtained in Example 1 and a 2 mm thick elastomeric strip (nitrile rubber NBR) impregnated in the oil were kept at 100 ° C. for 168 hours. After 168 hours, the average volume and hardness were measured and compared with the initial values. See Table 2 for the results.

Comparative example  A

Example 2 was repeated except that the base oil obtained solely from hydroisomerized and catalytic dewaxed Fischer-Tropsch wax was used in place of the base oil of Example 1. Pour point, viscosity and viscosity index of the oil were the same as those of Example 1 oil. The base oil consisted of 92% by weight paraffin. See Table 2 for the results.

Example 2 Comparison A Average volume Initial stage (g / cm 3) 0.8274 0.8122 Final (g / cm3) 0.8534 0.8343 change % 3.1 2.7 Average hardness Early* 84 83 final 81 81 change % -3.6 -2.0

(*) Measured by BS903: Part A16: 1987 / ISO 1817-1985

The results in Table 2 show that the base oil of Example 1 has improved seal expansion capacity.

Example  3

Partially dewaxed by contacting the waxy raffinate feed (No. 2) having the properties listed in Table 3 with the dewaxing catalyst used in Example 1 under 'first' dewaxing conditions. Fischer-Tropsch derived feeds were prepared. 'First' dewaxing conditions were 40 bar of hydrogen, a reactor temperature of 306 ° C., WHSV = 1.67 kg / l / h, and a hydrogen gas ratio of 750 Nl / kg feed. The effluent was analyzed as reported in Table 3.

88.5 parts by weight of the partially dewaxed Fischer-Tropsch feed were mixed with 11.5 parts by weight of a wide range of boiling waxed and hydrofinished oils having the properties listed in Table 3.

The pour point difference between the partially dewaxed Fischer-Tropsch feed and the extensive boiling mineral dewaxed and hydrofinished Oil-2 was +6 ° C.

Feed Wax Raffinate 2 Broad Boiling Mineral Dewaxed and Hydrofinized Oil-2 Partially De-Waxed Fischer-Tropsch Feed Density (D20 / 4) 0.784 0.863 0.814 Drop point (℃) +42 -15 -9 Nitrogen (ppmw) <1 <1 <1 Sulfur (ppmw) <2 33 <2 Kinematic viscosity at 100 ℃ 5.12 6.99 4.6 Initial boiling point (IBP) ℃ 356 341 203 IBP-390 ℃ (wt%) 6 8.8 11.3 390-520 ℃ (wt%) 82 85.2 78.3 520 ℃-FBP (wt%) 12 6 10.4 Final boiling point (FBP) ℃ 565 559 565 Wax Content (wt%) 18.2 (*) No wax Do not analyze

(*) Measured after solvent dewaxing at -27 ° C.

The blended feed as prepared above was contacted with the dewaxing catalyst used in Example 1. 'Second' dewaxing conditions were 40 bar hydrogen, reactor temperature 315 ° C., WHSV = 2.83 kg / l / h, and a hydrogen gas ratio of 500 Nl / kg feed.

From the effluent of the second dewaxing step, the 400 and 470 ° C. fractions were yielded as calculated in the original Shell MDS waxy raffinate and extensive boiling mineral dewaxed and hydrofinished oil-2 of Table 3. Obtained at 42% by weight.

The boiling point of the boiling fraction above 50 ° C. was −30 ° C., the cloud point was −24 ° C., and the kinematic viscosity at 100 ° C. was 4.103 cSt.

Claims (15)

Catalytic Pour Point Drop Treatment of a Mixture of (i) a Petroleum-derived Feed with a Pour Point Below -5 ° C., an Aromatic Content of 0-20% by Weight and a Naphthenic Compound Content of 15-90% by Weight; The content of the petroleum derived feed (i) in the mixture is 5 to 50% by weight), wherein the iso-paraffinic base oil having improved seal swelling properties. The process of claim 1 wherein the content of sulfur in the mixed feed for the pour point treatment is less than 50 ppm and the content of nitrogen in the mixed feed for the pour point treatment is less than 10 ppm. The process according to claim 1 or 2, wherein the petroleum derived feed has a saturate content of more than 98 wt%, a viscosity index of 80 to 150 and a sulfur content of less than 0.001 wt%. 4. The process according to any one of claims 1 to 3, wherein the petroleum derived feed comprises a hydrofinishing step carried out at a hydrogen pressure above 100 bar. The process according to any one of claims 1 to 4, wherein the base oil is hydrogenated after performing the pour point drop treatment so that the aromatic content is less than 1% by weight. 6. The catalytic depolymerization according to claim 1, wherein the catalytic pour point treatment is carried out in the presence of a catalyst and a binder comprising a Group VIII metal and a medium pore size zeolite having a pore diameter of 0.35 to 0.8 nm. The waxing process. The process according to claim 1, wherein the difference in pour point of the Fischer-Tropsch derived feed and the petroleum derived feed is less than 40 ° C. 8. 8. The method of claim 7, wherein the difference in pour point of the Fischer-Tropsch derived feed and the petroleum derived feed is less than 20 ° C. The method according to claim 1, wherein after performing the catalytic pour point treatment, hydrogen is separated from the dewaxed effluent, contacted with a heterosorbent selective for hydrogen sulfide removal, and the catalytic pour point drops. Recycling to treatment. 10. The method of claim 9, wherein the heterosorbent is zinc oxide. The process according to claim 1, wherein the Fischer-Tropsch feed is obtained by hydroisomerization of the Fischer-Tropsch product. The process of claim 11, wherein the hydroisomerized Fischer-Tropsch feed is obtained by the following steps: (a) hydrocracking / hydroisomerize the Fischer-Tropsch product, (b) separating the product of step (a) into one or more gas oil fractions and a high boiling Fischer-Tropsch derived feed. 13. The Fischer-Tropsch product of claim 12, wherein the Fischer-Tropsch product used as feed in step (a) has a weight ratio of at least 0.4 compound of at least 60 carbon atoms and at least 30 compound of carbon atoms in the Fischer-Tropsch product, At least 30% by weight of the compound in the product having at least 30 carbon atoms. Use of a base oil obtained by the process according to any one of claims 1 to 13 in gear oil applications. Use of a base oil obtained by the process according to any one of claims 1 to 13 in hydraulic oil applications.