NO139741B - PROCEDURE FOR PREPARING A LUBRICATION OIL BY HYDROCRACKING A WAX, DISTILLING AND DEWAXING THE RESIDUAL FRACTION - Google Patents

Description

The present invention relates to a method for producing a lubricating oil with a dynamic viscosity of

-17.8°C at a maximum of 24 P and a kinematic viscosity of 98.9°C

of at least 7.0 cSt, when hydrocracking wax.

According to the SAE classification, lubricating oils for internal combustion engines are divided on the basis of their viscosity into two groups, which are denoted by the names winter oil and normal oil. Each of these groups is further divided into a number of classes. Lubricating oils that are classified as winter oils are denoted by the letter W, with a number in front of the letter, e.g. SAE-5W, -10 W or -20 W oil. These oils must meet certain requirements regarding their dynamic viscosity at -17.8°C. Lubricating oils classified as normal oils are only designated with a number, e.g. an SAE-20, -30, -40 or -50 oil. These oils must satisfy a specific requirement regarding their kinematic viscosity at 98.9°C. Lubricating oils that only belong to one SAE class (either .....winter oil or normal oil) are referred to as simple lubricating oils. Examples of widely used simple lubricating oils are SAE-20 and SAE-30 oils. In addition to the simple lubricating oils, lubricating oils are also known which satisfy both the viscosity requirement of a class belonging to the winter oil and • the viscosity requirement of a class belonging to the normal oil. Used as engine oils, these universal oils have the advantage that in winter they are sufficiently thin not to cause difficulties in cold

.start, and are sufficiently thick at the engine's working temperature

to smudge properly. An important class of universal oils are the 10W/30 oils, which satisfy both the viscosity requirements of the SAE-10 W class (dynamic viscosity at -17.8° C of at least 12 P and a maximum of 2<>>+P measured according to ASTM standard D2602/71) and the viscosity requirement for the SAE-30 class (kinematic viscosity at 98.9° C of a minimum of 9.6 cSt and a maximum of 12.9 cSt, measured according to ASTM standard D ¥+5/71).

Production of universal oils of the lOW/30 class is carried out in practice by incorporating a number of additives with quality-improving properties into a base oil consisting of a lubricating oil or a mixture of lubricating oils with a high viscosity index obtained

conventionally or by hydrocracking, which base oil

"by itself does not satisfy lOW/30 specification.

Production of hby viscosity index lubricating oils in a conventional manner is carried out as follows. A paraffinic petroleum crude oil is separated by distillation at atmospheric pressure into a number of distillate fractions (especially successively into one or more petrol, kerosene and light gas oil fractions) and a residue (known as long residue). This long residue is then separated by distillations at reduced pressure into a number of distillate fractions (especially successively into one or more heavy gas oils, spindle oil, light machine oil and medium heavy machine oil fractions) and a residue (known as short residue). From the lubricating oil fractions obtained by the distillation at reduced pressure, the corresponding lubricating oils are produced by refining. Refining of the spindle oil fraction, the light machine oil fraction and the medium heavy machine oil fraction is carried out by removing aromatics and waxes from these fractions. When refining the short residue, asphalt is primarily removed from the residue. Aromatics and wax are then removed from the deasphalted oil. The residual lubricating oil produced in this way is referred to as filtered cylinder oil. The waxes obtained during refining of the different lubricating oil fractions are designated as distillate or residual crude wax, depending on the type of lubricating oil fraction from which they are derived.

Production of high viscosity-index lubricating oils by hydrocracking is carried out as follows: A heavy fraction of a paraffinic petroleum crude oil, such as a vacuum distillate, a deasphalted oil or a distillate or a residual crude wax, is fed over a suitable catalyst under hydrocracking conditions. One or more lubricating oil fractions, including a residual lubricating oil fraction, are separated by distillation from the hydrocracked product. From the lubricating oil fractions obtained in this way, the corresponding lubricating oils are produced by removing the wax from these fractions.

The lubricating oils which are produced as described above can either as such or after mixing, serve as base oils for the production of 10W/30 oils. As previously indicated, the lOW/30 oils are produced by incorporating a number of additives with quality-improving properties into the base oils. These additives can be divided into two groups. The first group includes, among other additives, those that inhibit oxidation (anti-oxidants), corrosion (corrosion inhibitors), formation of foam (anti-foam agents) and deposits in the engine (cleaning agents), as well as additives to improve the lubricating effect at high pressure (high pressure additives). The additives belonging to this group usually have a molecular weight

which does not exceed a value of 10,000 and is usually far below this value. The lubricating oil additive packages marketed by a number of manufacturers are usually composed of additives of this type. Incorporating such a lubricating oil additive package into a base oil has only a small effect on the oil's viscosity index, even if the additive package is used in a relatively high concentration. Depending on the composition of the additive package that is incorporated into the oil, the viscosity index of the oil remains constant, increases somewhat, or may even decrease somewhat. When later reference is made to "additive package" is meant a mixture of lubricating oil additives belonging to the above-mentioned first group. This mixture has the inherent

create that when it is incorporated into a base oil in a concentration of I? wt$ the viscosity index of this formulation (85 wt% base oil + 15 wt% of the blend) is no more than 10 units higher than the viscosity index of the base oil. The second group of additives with quality-improving properties used in the production of lOW/30 oils includes viscosity index improvers.

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The additives in this group usually have a molecular weight that exceeds a value of 10,000 and is frequently above this value.

The use of viscosity index improvers in the production of universal lubricating oils has serious disadvantages. In the first place they are. high molecular compounds (usually polyalkyl acrylates and poly-alkyl methacrylates) used for this purpose are insufficiently resistant to the cutting forces occurring in the engine, and are furthermore sensitive to oxidation. As a result of this, the polymers in the engine decompose, and in addition to polluting the engine mad fission products, a permanent reduction in the viscosity of the oil takes place. Furthermore, a temporary loss of viscosity occurs while the lubricating oil is being used because the polymers are oriented under the influence of the shearing forces in the engine, leading to reduced internal friction. As the shear forces increase, the apparent viscosity of the polymer-containing oil will approach that of the polymer-free oil.

As can be seen from the above, there is a great need

for lubricating oils meeting the -10W/30 specification without the addition of a polymer viscosity index improver. Attempts to produce such oils in a conventional manner, i.e. by distillation and refining have not been successful.

It has now been found that lubricating oils meeting the 10W/30 specification either as such or after the addition of an additive package, but without the addition of a polymer viscosity index improver, can be produced at a yield of more than 15% by weight, based on the starting material, by catalytic hydrocracking of waxes , with the proviso that the subsequent requirements with respect to the starting material, catalyst, hydrocracking conditions and processing are met.

The starting material must consist of wax of which more than 40% by weight boils above 520° C and which is obtained by dewaxing a residual mineral oil fraction.

The hydrocracking catalyst must contain nickel sulphide

. and in addition molybdenum sulphide and/or tungsten sulphide.

The carrier material in the catalyst must consist of aluminum oxide and the catalyst must also contain fluorine.

The hydrocracking process must be carried out at a temperature between

.3 60° C and h25° C and further under such conditions that the resulting liquid reaction product consists of 25 to 95 wt.

of components with a boiling point above 400°C.

The processing shall be carried out by separating the reaction product by distillation into one or more light fractions and a residual fraction with an initial boiling point between 350 and 470°C and producing the desired lubricating oil from this fraction by means of dewaxing.

Lubricating oil produced in this way which satisfies the 10W/30 specification, either as such or after the addition of an additive package, but without the addition of a polymeric viscosity index improver, can be characterized as a lubricating oil with a dynamic viscosity of a maximum of 24 P at -17.8° C (measured according to ASTM standard D 2602/71) and a kinematic viscosity of at least 7.0 and preferably of at least cSt at 98.9°C (measured according to ASTM standard D 445/71).

The invention therefore relates to a process for producing a lubricating oil with a dynamic viscosity of a maximum of 24 P at -17.8°C and a kinematic viscosity of at least 7.0 cSt at 98.9°C from wax in a yield of more than 25 % by weight, in which process wax is converted by hydrocracking at a temperature of between 360 and 425°C, a pressure of from 10 to 250 bar, a space velocity of 0.2 to 5 kg of starting material per liter of catalyst per ti-me and a hydrogen/starting material ratio of 100 to 5000 NI hydrogen per kg of starting material over a 0.5 - 7% by weight fluorine sulphide catalyst containing 0.025 - 0.8 gram atoms of nickel and in addition 0.05 - 0.5 gram atoms of molybdenum and/or tungsten per 100 g of aluminum oxide as a carrier, during the formation of a liquid product, which method is characterized by using a wax of which more than 40% by weight boils above 520°C, and which is obtained by dewaxing a residual mineral oil fraction (hereinafter referred to as "starting material wax "), and where 25 - 95% by weight of the specified liquid product consists of components with a boiling point above 400°C, and where the reaction product is then separated by distillation into one or more light fractions and a residual fraction with an initial boiling point between 350 and 470°C , from which the desired lubricating oil is produced by dewaxing.

The wax that is used as starting material in the method according to the invention (in the description and claims this wax is given the designation "starting wax") is preferably obtained as a by-product during the production of lubricating oil in a conventional way or when producing lubricating oil by hydrocracking. As explained above, when producing the lubricating oil in a conventional manner, a residual lubricating oil fraction is obtained from which a residual lubricating oil is produced by refining. This refining includes the removal of asphalt, aromatics and waxes. This wax is preferably starting material wax. Before the residual lubricating oil fraction can be dewaxed, asphalt must first be removed. Deasphalting can be carried out by treating the residual lubricating oil fraction with a low-boiling paraffinic hydrocarbon, such as ethane, propane, butane or pentane, propane being preferred. Aromatics and waxes are then removed from the deasphalted oil obtained in this way. Removal of aromatics from the deasphalted oil can be accomplished by treating the deasphalted oil with a selective solvent for aromatic hydrocarbons, such as furfural, phenol, cresol or "Chlorex", furfural being preferred. Finally, wax is removed from the resulting oil, which is termed a waxy cylinder oil raffinate. Dewaxing of the oil is carried out by cooling the oil in the presence of a solvent. The dewaxing is preferably carried out with a mixture of methyl ethyl ketone and toluene at a temperature of between -10°C and -40°C and a ratio between solvent and oil (volume ratio) of 1 to 1 and 10 to 1. The order the way in which the removal of aromatics and wax from the deasphalted oil takes place is in principle arbitrary, but in order to reduce the volume of oil that is cooled during dewaxing, the dewaxing should preferably be carried out after the aromatics have been removed from the deasphalted oil.

As explained above, when producing a lubricating oil by hydrocracking, a residual lubricating oil fraction is obtained from which a residual lubricating oil is produced by removing wax. This wax is also a preferred starting material wax, with the proviso that the residual lubricating oil fraction from which it has been obtained by dewaxing is a residual fraction of a hydrocracked product which has been produced either by hydrocracking under mild conditions a residual fraction of a crude mineral oil or by hydrocracking of wax obtained by dewaxing a residual fraction of a crude mineral oil. The term "hydrocracking under mild conditions" in this description indicates hydrocracking under such conditions that a hydrocracked product is obtained of which less than 50% by weight boils below the initial boiling point of the starting material. If a starting material wax is used which is obtained by dewaxing a residual fraction of a hydrocracked product which has been produced by hydrocracking under mild conditions of a residual fraction of a crude mineral oil, this residual fraction is preferably the same deasphalted residual lubricating oil fraction previously mentioned as a source of starting material wax which is obtained by dewaxing. If a starting material wax is used which has been obtained by dewaxing a residual fraction of a hydrocracked product which has been produced by hydrocracking wax obtained by dewaxing a residual fraction of a crude mineral oil, this residual fraction is preferably the same deasphalted residual lubricating oil fraction or a raffinate obtained from this by the removal of aromatics which has previously been mentioned as a preferred source of starting material wax obtained by dewaxing.

The starting material wax preferably contains less

than 35% oil by weight. It is further preferred that the residual mineral oil fraction from which the starting material wax is obtained by dewaxing is an oil fraction which after dewaxing at -30°C has a viscosity index of at least 55, and preferably at least 70.

The catalysts used in the hydrocracking of the starting material wax are fluorine-containing sulphide catalysts containing nickel and in addition molybdenum and/or tungsten on aluminum oxide as a carrier. Preferred catalysts are those containing 0.025 - 0.8 g atoms and preferably 0.05 - 0.7 g atoms of nickel and 0.05 - 0.5 g atoms, preferably 0.1 - 0.4 g atoms of molybdenum and/or tungsten per 100 g aluminum oxide.

The metals can be incorporated into the catalyst in any known way in the production of catalysts containing several components on a support, e.g. by co-impregnation of aluminum oxide in one or more steps with an aqueous solution containing salts of the metals concerned. The catalysts are used in sulphide form. The catalysts can be sulphided by any known method for sulphiding catalysts, e.g. in that the catalysts are brought into contact with a mixture of hydrogen and hydrogen sulphide or with hydrogen and a sulphurous hydrocarbon oil, such as a sulphurous gas oil.

In addition to the metals nickel and molybdenum and/or tungsten, the catalysts used in the hydrocracking of the starting material must also contain fluorine. Incorporation of fluorine into the catalysts can in principle be carried out in two ways. Fluorine can be incorporated into the catalyst by impregnating it during or after production with a suitable fluorine compound, such as ammonium fluoride. It is also possible to incorporate fluorine into the catalyst by in situ fluorination of the catalyst at an early stage of the hydrocracking process in which the catalyst is used (e.g. during or after starting the process). In situ fluorination of the catalysts can be carried out by adding a suitable fluorine compound, such as o-fluorotoluene or difluoroethane to the gas and/or liquid stream which is passed over the catalyst. In several cases, it may be preferred to incorporate at least part of the fluorine in the catalyst by in situ fluorination. The amount of fluorine contained in the catalysts is preferably 0.5-7% by weight. In addition to nickel, molybdenum and/or tungsten and fluorine, the catalysts used in the hydrocracking of the starting material can further contain activators such as boron and phosphorus.

In the production of lubricating oil by hydrocracking the starting material wax according to the invention, very good results are achieved by using one of the following catalysts.

(a) A catalyst prepared by impregnating aluminum oxide with a solution containing one or more nickel compounds, one or more molybdenum and/or tungsten compounds, phosphate ions and peroxide ions, and

then dry and calcine the material.

(b) A catalyst produced by incorporating into an aluminum oxide hydrogel one or more nickel compounds and one or more molybdenum and/or tungsten compounds in sufficient concentration to cause a metal content, expressed as metal oxides, of 30 - 65% by weight of the finished catalyst, and then dry and calcine the material and where aluminum oxide hydrogel in which metal

the compounds are incorporated after drying and calcination gives a xerogel with a compressed bulk density of 0.75

to 1.6 g/ml and a pore volume of 0.15 to 0.5 ml/g.

(c) A catalyst prepared by treating a material containing aluminum oxide, water, one or more water-soluble salts of nickel and one or more water-soluble salts of molybdenum and/or tungsten, with a hydrogen sulphide-containing gas at a temperature below 150° C

and then heat the material in a hydrogen-containing gas to a final temperature above 200°C, where the amount of water present in the material treated with the hydrogen sulphide-containing gas must correspond to the amount of water present in the material after drying in a dry gas at 110° C, increased by 20 to 120% of the amount of water that the dried material can absorb in the pores of the support at 20°C.

The catalysts used in the hydrocracking of the starting material preferably contain nickel or nickel and tungsten as catalytically active metal components.

Hydrocracking of the starting material wax can be carried out at a temperature between 350 and 425°C, and in addition under such conditions that 25 - 95% by weight of the resulting liquid reaction product consists of components with a boiling point above 400°C. Suitable hydrocracking conditions are a pressure of 10 - 250 bar, a space velocity of 0.2 - 5 kg of starting material per liters of catalyst/hour and a hydrogen/starting material ratio of 100 to 5000 NI hydrogen per kg starting material. Hydrocracking of the starting material wax is preferably carried out under the following conditions: a temperature of 360° C to ¥15° C, a pressure of 25 to 200 bar, a space velocity of 0.5 to 1.5 kg of starting material per hour. liter of catalyst per hour and a hydrogen/starting material ratio of 500 to 2500 NI per kg starting material.

The starting material wax is converted by hydrocracking into a liquid product, of which 25 to 95 wt# consists of components with a boiling point above h00° c, and the reaction product is separated by distillation into one or more light fractions and a residual fraction with an initial boiling point between 350° and hjO<0 > C. Preferably, the starting material is converted by hydrocracking into a liquid product, of which ^f0 to 70% by weight consists of components with a boiling point above h00° C and a residual fraction with an initial boiling point between 390° and K50<0> C which is separated by distillation from the reaction product.

In order to produce a suitable lubricating oil from the residual fraction, this must be dewaxed. The dewaxing is preferably carried out by cooling the oil in the presence of a solvent. Very suitable for this purpose is a mixture of methyl ethyl ketone and toluene with a temperature between -10° C and -^O0 C and a solvent-oil volume ratio between 1 to 1 and 10 to 1. To increase the yield of the desired lubricating oil, it is preferred to recycle to the hydrocracking reactor at least part of the wax that is separated during the dewaxing of the residual fraction of the hydrocracked product produced by hydrocracking the starting material wax.

Method according to the invention makes it possible to produce lubricating oils which as such, i.e. without additives being incorporated, satisfy the 10W/30 specification. The method according to the invention also makes it possible to produce lubricating oils which as such do not satisfy the 10W/30 specification,

but from which a lOW/30 oil can be produced in a simple way without the use of high-molecular viscosity index improvers by incorporating a specific amount of an additive package.

The commercial additive packages that are used in the practical production of universal lubricating oils comprise a large number of compounds, each of which has the property that when they are incorporated into a lubricating oil, they improve the quality of this lubricating oil in one or more respects. Examples of additives contained in these additive packages are anti-oxidants, rust inhibitors, corrosion inhibitors, anti-wear agents, anti-foam agents, cleaning agents, metal passivating agents and high-pressure additives.

In some cases, several quality-improving properties are combined in a single additive. If the lubricating oils produced according to the invention are intended for use as motor oils, it is advisable to incorporate a certain amount of additive package, even if the lubricating oil as such satisfies the lOW/30 specification. When producing lOW/30 oils according to the invention, it is preferred to incorporate such an amount of the additive package into the base oil (which may or may not satisfy the 10W/30 specification), that an oil composition comprising 87.5 to 95% by weight of the base oil is obtained and 5 to 12.5$ additives.

The invention shall be further illustrated by means of the following examples.

Eight catalysts (A - H) were used in hydrocracking experiments in the production of lubricating oil from six residual waxes (I-VI). The catalysts and starting materials are described in detail below.

CATALYST A: Ni/Mo/F/Alo0-. catalyst with a pore volume

of 0.¥+ ml/g and a specific surface area of 117.1 m 2/g containing 6 parts by weight nickel, 30 parts by weight molybdenum and 7.5 parts by weight fluorine per 100 parts by weight aluminum oxide. This catalyst had been prepared by co-impregnation of aluminum oxide with an aqueous solution of ammonium molybdate, nickel nitrate and ammonium fluoride. After the degree of wetting had been set to 100$, the material was first treated for 16 hours with H^S at 15 bar and 75<*>C; after which it was heated for two hours to ^00° C in a stream of H2S-containing H2(9 volume H2S, 10 bar, 25000 NI.l"<1>hour~<1>) and finally kept for about 2 hours in this gas space (the term "humidity degree"; as used here refers to the amount of water present in the material in addition to the amount of water that is then present after drying the material in a dry gas at 110° C. The degree of wetting is expressed as a percentage of the amount of water that the dry material can absorb in the pores of the carrier at 20° C). ;CATALYST B: Ni/Mo/F/Al^ catalyst with a pore volume of 0.23 ml/g and a specific surface area of 63.0 m<2>/g containing 6 parts by weight nickel, 30 parts by weight molybdenum and 7.5 parts by weight fluorine per 100 parts by weight of aluminum oxide This catalyst had been prepared in the same way as catalyst A with the exception that in the present case a different type was used aluminum oxide. ;CATALYST C: Ni/W/F/A120^ containing 5 parts by weight nickel, ;38 parts by weight tungsten per 100 parts by weight of aluminum oxide and 2.k-% by weight of fluorine. This catalyst had been prepared in the same way as catalysts A and B, with the exception that in the present case a fluorine-free impregnation liquid containing ammonium tungstate and nickel nitrate was used and that fluorine was incorporated into the catalyst by fluorination in situ. CATALYST D: Ni/Mo/P/F/AlgO^ catalyst containing h, 2 parts by weight nickel, 17.7 parts by weight molybdenum and 3.1 parts by weight phosphorus per 100 parts by weight aluminum oxide and 1.6% by weight fluorine. This catalyst had been produced by co-impregnation of aluminum oxide with an aqueous solution containing nickel nitrate, phosphoric acid, ammonium molybdate and hydrogen peroxide, and then drying and calcining the material. Fluorine was incorporated into the catalyst by fluorination in situ. CATALYST E: Ni/W/F/Al20^ catalyst containing 31 parts by weight nickel, 58 parts by weight tungsten 7.5 parts by weight fluorine per 100 parts by weight aluminum oxide. CATALYST F: Ni/W/F/Al^ catalyst containing 31 parts by weight of nickel and 58 parts by weight of tungsten per 100 parts by weight aluminum oxide and 6 parts by weight fluorine. CATALYST G: Ni/W/F/Al^ catalyst contains 37 parts by weight of nickel and 70 parts by weight of tungsten per 100 parts by weight aluminum oxide and ;>+.3 weight# fluorine. Catalysts E, F and G were prepared by mixing an aluminumoxy hydrogel with an aqueous solution containing nickel nitrate, ammonium tungstate and ammonium fluoride, the pH of the solution being brought to 5.6 using 25% ammonia. The mixture was heated to 80° C., the gel was filtered, extruded, dried and calcined. After drying and calcining, the aluminum oxide hydrogel was used in the preparation of these catalysts which gave a xerogel with a compressed space density between 0.75" and 1.6 g/ml and a pore volume between 0.15 and 0.5 ml/g.; CATALYST H: Ni/W/F/Al^ catalyst containing 10 parts by weight of nickel and 60 parts by weight of tungsten per 100 parts by weight of aluminum oxide and H.5 by weight of fluorine This catalyst was prepared by -impregnation of aluminum oxide with an aqueous solution containing nickel nitrate and ammonium tungstate and then drying and calcining. Fluorine was incorporated into the catalyst by in situ fluorination. ;In situ fluorination of catalysts C, D and H was carried out ;by adding o-fluorotoluene to the starting material' during the initial step of the hydrocracking process. ;STARTING MATERIAL I (crude wax from clear cylinder oil) ;Wax obtained by dewaxing a residual lubricating oil fraction (1) ;which had previously been deasphalted with propane and extracted with furfural. Initial boiling point of the wax: 520° C. Ol je content in the wax: 19.7 wt$. Viscosity index of the oil obtained after the wax was deoiled: 97. Sulfur content, in the wax: 0.3!+ wt%. ;STARTING MATERIAL II (DA0 raw wax) ;Wax obtained by dewaxing a residual lubricating oil fraction (1) ;which had previously been deasphalted with propane. Initial boiling point of the wax: 520° C. Oil content of the wax: 9.8 wt. Viscosity index of the oil obtained after deoiling the wax: 78. Sulfur content in the wax: 0.85 wt. ;STARTING MATERIAL III (crude wax from clear cylinder oil) ;Wax obtained by dewaxing a residual lubricating oil fraction (1) ;which had previously been deasphalted with propane and extracted with furfural. Initial boiling point of the wax: 520° C. Oil content in the wax: 21.1 wt#. Viscosity index of the oil obtained after the wax had been deoiled: 98. Sulfur content in the wax: 0.66% by weight. ;STARTING MATERIAL IV (wax from hydrocracked crude wax from clear cylinder oil) ;Wax obtained by dewaxing a residual fraction of a hydrocracked product which had been produced by hydrocracking wax obtained by dewaxing a residual lubricating oil fraction (1) which had previously been deasphalted with propane and extracted with furfural. Initial boiling point of the starting material wax: 390° C. Of this wax, 92.5 wt% boiled above 520° C. Oil content of the starting material wax: 6 wt$. Viscosity index of the oil obtained after the starting material wax had been deoiled: 1^9. Sulfur content in the starting material wax: 20 ppmv. ;STARTING MATERIAL V (wax from hydrocracked crude wax from clear cylinder oil). ;Wax obtained by dewaxing a residual fraction of a hydrocracked product which had been produced by hydrocracking wax obtained by dewaxing a residual lubricating oil fraction (1) which had previously been deasphalted with propane and extracted with furfural. Initial boiling point of starting material: 520° C. Oil content in the starting material wax: 7 wt. Viscosity index of the oil obtained after the starting material wax had been deoiled: 150. Sulfur content in the starting material wax: 20 ppmv. ;STARTING MATERIAL VI (wax from mild hydrocracked DA0) ;Wax obtained by dewaxing a residual fraction of a hydro-cracked product which had been produced by mild hydrocracking (25% by weight of the hydrocracked product -boiled below the initial boiling point of the starting material) of a residual - lubricating oil fraction (1); which had previously been deasphalted with propane. Initial boiling point of the starting material wax: 520 C. 01je content in the starting material wax: 21 wt. Viscosity index of the oil obtained after the starting material wax had been deoiled: 95" Sulfur content in the starting material wax: 500 ppmv. The six residual lubricating oil fractions (1) from which the starting material waxes I-VI had been prepared were obtained as a residue by distillation under reduced pressure of distillation residues at atmospheric pressure of paraffinic crude oils. The dewaxing was carried out by cooling the oils to a temperature of -30°C in the presence of a 1:1 mixture of methyl ethyl ketone and toluene. The viscosity indices stated in this description were determined according to ASTM standard D 2270. The hydrocracking experiments 1-26 were carried out under the following conditions: pressure: 150 bar, except in experiment 7, this experiment was carried out at a pressure of 50 bar. ;temperature: 375-¥10° C. ;space velocity: 1 1.1 "'"hour-"'" ;hydrogen/starting material ratio: 2000 NI.I<-1>;catalyst layer: 100 ml ;The catalysts were used in sulphide form . The sulphidation of the catalysts D-H was carried out by bringing them into contact with hydrogen and a sulfur-containing gas oil. During hydrocracking of starting materials IV-VI, butyl mercaptan was added to these starting materials in an amount sufficient to increase the total sulfur content of these starting materials to 2500 ppmv. Residual fractions with an initial boiling point between 365° and ¥+0° C were separated from the hydrocracked products by distillation. From the residual fractions, the corresponding lubricating oils were produced by dewaxing the fractions. The dewaxing was carried out by cooling the oil to a temperature of -30° C in the presence of a 1:1 mixture of methyl ethyl ketone and toluene. Experiments 1-26 shown in table A are all hydrocracking experiments according to the invention. Each of these tests yields more than 15% by weight, based on the starting material, of a lubricating oil with a dynamic viscosity of a maximum of 2h P at -17.8° C and a kinematic viscosity of at least 7.0 cSt at 98.9° C. The lubricating oils produced according to trials 1-11 as such satisfy the 10W/30 specification (dynamic viscosity at -17.8° C of at least 12 P and a maximum of 2h P and kinematic viscosity at 98.9° C of at least 9.6 cSt and a maximum 12.9 cSt) like this, i.e. without the incorporation of additives. An additive package was incorporated into the lubricating oils produced according to trials 12-23 which did not meet the 10W/30 specification and into the lubricating oils produced according to trials 8-11 which did not meet the lOW/30 specification. Two additive packages were used, respectively designated additive package A and B. These additive packages differed with regard to the chemical composition of the additives they contained, but both had essentially the same effect, with regard to anti-oxidation, rust inhibition, wear-reducing ability, corrosion inhibition, foam inhibition , metal passivation, improvement of the lubricating effect at high pressure and inhibition of deposits in the engine. Inhibition of additive package A in the lubricating oils produced a lubricating oil composition containing 92.5% by weight of the base oil and 7.5% by weight of the additive package. Incorporation of additive package B in the lubricating oil gave a lubricating oil composition containing 89.9% by weight of the base oil and 10.1% by weight of the additive package. The properties of the produced oil compositions are shown in table B. The results above in table B show that lubricating oils produced according to the invention which as such do not satisfy the 10W/30 specification (compare tests 12-23) can be formulated into lOW/30 oils on a simple way without the addition of the usual high-molecular viscosity improvers, by incorporating the additive package A or B. Incorporation of these additive packages into a lubricating oil produced according to the invention which as such satisfies the lOW/30 specification (compare trials 8-11) gave a lOW/30 better quality oil. In the method according to the invention, it is essential to use a fluorine-containing sulphide catalyst which contains nickel and/or cobalt and in addition molybdenum and/or tungsten on aluminum oxide as a carrier. Two hydrocracking experiments were carried out for the sake of comparison. In the first trial, a fluorine-free catalyst based on aluminum oxide was used, and in the second trial, a fluorine-containing catalyst based on silicon oxide/aluminium oxide. The two trials are described in detail in the following. COMPARATIVE EXPERIMENT 1 A Ni/Mo/P/A^O^ catalyst containing <*>+.2 parts by weight nickel, 17.7 parts by weight molybdenum and 3.1 parts by weight phosphorus per 100 parts by weight of aluminum oxide (catalyst D without fluorine) was used in the hydrocracking of starting material I under the same conditions as used in experiment 3, with the exception that in the present case the hydrocracking temperature was 1+ 1+5° C. The lubricating oil was worked up at the same manner as described in trial 3" Table C shows the results of comparative trial 1 and trial 3.

The results shown in Table C show that the fluorine-free catalyst is unsuitable for the present purpose. At a hydrocracking temp

at 39Lf-°C a fluorine-containing catalyst gives et. lubrication oil yield on

27 wt#, at a hydrocracking temperature of ¥+5°C, it gave fluorine-

free catalyst a fuel oil yield of only 12 wt$ (note that both a hydrocracking temperature of ¥+5°C and a fuel oil yield of 12 wt$ are outside the scope of the invention).

COMPARATIVE EXPERIMENT 2

A Ni/W/F/SiO2-Al20 catalyst containing 9 wt# of nickel, 17 wt% of tungsten and 2.5 wt% of fluorine on a support consisting of 26 wt% of aluminum oxide, the remainder being silicon oxide, was used in the hydrocracking of a wax obtained by dewaxing a residual lubricating oil fraction that was deasphalted with propane (if the viscosity index

to the deasphalted oil after dewaxing at -19°C: 77). The remaining lubricating oil fraction from which the wax (DAO raw wax) was produced

was obtained by distillation under reduced pressure of a distillation residue at atmospheric pressure of a North African crude oil. Dewaxing was carried out by cooling the oil to a temperature of -27°C in the presence

of a 1:1 mixture of methyl ethyl ketone and toluene. Hydrocracking of the wax took place using the catalyst in sulphide form at a temperature of 350°C, a pressure of 50 bar, a space velocity of kg.l 1.hour 1 and a hydrogen/starting material ratio of 150 Nl/kg oil. A residual fraction with an initial boiling point of <L>f00°C was separated from the hydrocracked product by distillation and dewaxed by cooling the oil to a temperature of -27°C in the presence of a 1:1 mixture of methyl ethyl ketone and toluene. Thus, a dewaxed residual lubricating oil fraction was obtained in a yield of 20% by weight, based on the starting material, with a viscosity index of 100, a kinematic viscosity at 98.9°C of 16.9 cSt and a dynamic viscosity at

-17.8°C in excess of 200 P.

The results of this experiment show that a silicon oxide-aluminium oxide based catalyst is unsuitable for the present purpose. The viscosity of this resulting lubricating oil shows no resemblance to a lOW/30 oil and it is impossible to produce a lOW/30 oil from the lubricating oil by incorporating an additive package.

Claims (2)

1. Process for the production of a lubricating oil with a dynamic viscosity of a maximum of 24 P at -17.8°C and a kinematic viscosity of at least 7.0 cSt at 98.9°C from wax in a yield of more than 25% by weight , in which process wax is converted by hydrocracking at a temperature of between 360 and 425°C, a pressure of from 10 to 250 bar, a space velocity of 0.2 to 5 kg of starting material per liter of catalyst per hour and a hydrogen/starting material ratio of 100 to 5000 NI hydrogen per kg. starting material, over a 0.5 - 7% by weight fluorine-containing sulphide catalyst containing 0.025 - 0.8 gram atoms of nickel and in addition 0.05 - 0.5 gram atoms of molybdenum and/or tungsten per 100 g of aluminum oxide as a carrier, during the formation of a liquid product, characterized in that a wax is used of which more than 40% by weight boils above 520°C, and which is obtained by dewaxing a residual mineral oil fraction (hereinafter referred to as "starting material wax"), and where 25 - 95% by weight of the specified liquid product consists of components with a boiling point above 400°C, and where the reaction product is then separated by distillation into one or more light fractions and a residual fraction with an initial boiling point between 350 and 470°C, from which the desired lubricating oil is produced by dewaxing. 2. Process according to claim 1, characterized in that the starting material wax is converted by hydrocracking into a liquid product of which 40 - 70% by weight consists of components with a boiling point above 400°C, and where the reaction product is separated by distillation into one or more light fractions and a residual fraction with an initial boiling point between 390 and 450°C.