US3830723A

US3830723A - Process for preparing hvi lubricating oil by hydrocracking a wax

Info

Publication number: US3830723A
Application number: US00343614A
Authority: US
Inventors: P Ladeur; Gooswilligen G Van
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1972-04-06
Filing date: 1973-03-21
Publication date: 1974-08-20
Anticipated expiration: 1991-08-20
Also published as: BE797764A; JPS4917403A; NO139741C; FR2179113A1; FI55045B; SE396614B; GB1429494A; DK140805B; DK140805C; CA1003778A; DE2316882A1; NO139741B; JPS5717037B2; FI55045C; IT983661B; DE2316882C2; FR2179113B1

Abstract

A LUBRICATING OIL MEETING THA SAE-10W/30 SPECIFICATION IS PREPARED FROM WAX OBTAINED FROM A DE-ASPHALTED RESIDUAL MINERAL OIL FRACTION BY HYDROCRACKING AT 325425*C. OVER A FLUORINE-CONTAINING ALUMINA-SUPPORTED MIXED SULFIDE CATALYST TO GIVE A LIQUID PRODUCT CONTAINING 25-85% WT. MATERIAL BOILING ABOVE 400*C., ISOLATING A RESIDUAL FRACTION HAVING AN INITIAL BOILING POINT BETWEEN 350 AND 470*C., AND DEWAXING THAT FRACTION.

Description

US. Cl. 2o s-10s United States Patent PROCESS FOR PREPARING HVI LUBRICATING 13/06 Int Cl C g 11 Claims ABSTRACT OF THE DISCLOSURE A lubricating oil meeting the SAE-lOW/ 30 specification is prepared from wax obtained from a de-asphalted residual mineral oil fraction by hydrocracking at 325- .425 C. over a fluorine-containing alumina-supported .mixed sulfide catalyst to give a liquid product contain ng -85% wt. material boiling above 400 C., isolating a residual fraction having an initial boiling point between 350 and 470 C., and dewaxing that fraction.

Background of the Invention The invention relates to a process for the preparation of a lubricating oil having a dynamic viscosity at 17.8

C. of at most 24 P (Poise) and a kinematic viscosity at 98.9 C. of at least 7.0 cst. (centistokes), by hydrocracking of wax.

According to the SAE classification, lubricating oils for combustion engines are divided on the basis of their viscosity into two groups which are designated by the names winter grade and normal grade. Each of these groups is subdivided into a number of classes. Lubricating oils as regards their kinematic viscosity at 98.9 C. Lubricating oils which only belong to one SAE class (either of the Winter grade or of the normal grade) are designated as single grade lubricating oils. Examples of widely used single grade lubricating oils are SAE-20 and SAE-30 oils.

In addition to the single grade lubricating oils, lubricating oils are also known which satisfy the viscosity requirement both of a class of the winter grade and the viscosity "ice (dynamic viscosity at -17.8 C. at least 12 P and at most 24 P, measured according to ASTM Standard D2602/7l) and the viscosity requirement for the SAE-30 class (kinematic viscosity at 98.9 C. at least 9.6 cst. and at most 12.9 cst., measured according to ASTM Standard D 445/71).

The preparation of multigrade lubricating oils in the 10W/ 30 class is effected in practice by incorporating a number of additives with quality-improving properties in a base oil consisting of a lubricating oil or a blend of lubricating oils having a high viscosity index obtained in the conventional manner or by hydrocracking, which base oil in itself does not satisfy the 10W/ 30 specification.

The preparation of high-viscosity index lubricating oils in the conventional manner is carried out as follows. A parafiinic petroleum crude oil is separated by distillation at atmospheric pressure into a number of distillate fractions (in particular successively into one or more gasoline, kerosine and light gasoil fractions) and a residue (known as long residue). This long residue is then separated by distillation at reduced pressure into a number of distillate fractions (in particular successively into one or more heavy gasoil, spindle oil, light machine oil and medium heavy machine oil fractions) and a residue.

(known as short residue). From the lubricating oil fractions obtained during the distillation at reduced pressure, the corresponding lubricating oils are prepared by refining. The refining of the spindle oil fraction, light machine oil fraction and medium heavy machine oil fraction is effected by removing aromatics and wax from these fractions. 'In refining the short residue, asphalt is first of all removed from the residue. From the deasphalted oil thus obtained, aromatics and wax are subsequently removed. The residual lubricating oil prepared in this way is designated as bright stock. The wax obtained during refining of the various lubricating oil fractions is designated as distillate or residual slack wax, depending on the type of lubricating oil fraction from which arey are derived.

The preparation of high viscosity-index lubricating oils by hydrocracking is carried out as follows. A heavy fraction of a parafiinic petroleum crude oil such as a heavy distillate or a deasphalted oil is passed over a suitable catalyst under hydrocracking. conditions. One or more lubricating oil fractions are separated by distillation from the hydrocracked product. From the lubricating oil fractions obtained in this way the corresponding lubricating oils are prepared by removing wax from these fractions.

The lubricating oils prepared in the mannerdescribed above, may, either as such or after blending, serve as base oils for the preparation of 10W/30 oils. As stated'p'reviously, the 10W/3O oils are prepared byincorporating in the base oils a number of additives with quality-improving properties. These additives may be divided into two groups. The first group comprises inter alia the additives to inhibit oxidation (anti-oxidants), corrosion (corrosion inhibitors), the formation of foam (anti-foaming'agents) and deposits in the engine (detergents), as well as additives to improve the lubricating eifect at high pressure (extreme pressure additives). The additives belonging to this group generally have a molecular weight which does intlxged a 'y liii pf not nd s generally. far e o this value. The lubricating oil additive packages marketed by a number of manufacturers are generally composed of additives of this type. i

The incorporation of such a lubricating oil additive package in a base oil has only a slight effect on the viscosity index of this oil, exen if the additive package is used in a rather high concentration. Depending on the composition of the additive package which is incorporated in the oil, the viscosity index of the oil either remains ponstant, increases somewhat, or may even decrease slightly. Whenever reference is made hereinafter to additive package" this reference should be taken as meaning 'a blend of lubricating oil additives belonging to the abovementioned first group, which blend has the property that when it is incorporated in a base oil in a concentration of 15% by weight, the viscosity index of this formulation (85% by weight of base oil 15% by weight of blend) is not more than units higher than the viscosity index of the base oil.

The second group of additives having quality-improving properties used in the preparation of W/ 30 oils includes the viscosity index improvers. The additives in this group generally have a molecular weight exceeding a value of 10,000 and frequently far in excess of this value.

There are serious drawbacks to the use of viscosity index improvers for the preparation of the present multigrade lubricating oils. In the first place, the high molecular weight compounds (generally polyalkylacrylates and polyalkylmethacrylates) used for this purpose are insufficiently resistant to the shearing forces which occur in the engine and moreover they are sensitive to oxidation. As a result of this the polymers are decomposed in the engine and, in addition to fouling of the engine by decomposition products, a permanent decrease 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 become oriented under the influence of the shearing forces in the engine, which leads to reduced internal friction. As the shearing forces increase the apparent viscosity of the polymer-containing oil approaches t that of the polymer-free oil.

It is clear from the above that there is an urgent need for lubricating oils which satisfy the 10W/30 specification without the addition of a polymeric viscosity index improver. Attempts to prepare such oils in the conventional manner, i.e. by distillation and refining, have remained without success.

THE INVENTION ing requirements regarding starting material, catalyst, hydrocracking conditions and product separation are met.

The starting material consists of wax of which more 'than'30% wt. boils above 520 C. and which is obtained during the dewaxing of a residual mineral oil fraction.

" "The hydrocracking catalyst contains nickel sulfide and/ "or'cobalt sulfide and in addition molybdenumsulfide an'd/ "or; tungsten sulfide supported on alumina, and the catalyst :also contains fluorine.

The hydrocracking process is carried out at a temperatu're between 325 C and 425 C. and further under such conditions that the resultant liquid reaction product consists'of 25% to 95% by weight of components having a 'boiling point in excess of 400 C.

The-reaction product is separated by distillation into one or more light fractions and a residual fraction having an initial boiling point between 350 C. and 470 C. and the desired lubricating oil is prepared from the residual fraction by means of dewaxing.

The lubricating oils prepared inth is manner which satisfy the 10W/30 specification either as such of after the addition of an additive package, but without the addition of a polymeric viscosity index improver, may be characterized as lubricating oils having a dynamic viscosity of at most 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 8.4 cst. at 98.9 C.( measured according to ASTM standard D 445/71 The wax used as starting material in the process according to the invention is preferably obtained as by-product during the preparation of lubricating oil in a conventional manner. As was explained above, in the preparation of lubricating oil in a conventional manner a residual lubricating oil is prepared by refining. This refining comprises the removal of asphalt, aromatics and wax. This wax 'is the preferred starting material in the process according to the invention. Before the residual lubricating oil fraction can be dewaxed, asphalt first has to be removed therefrom. De-asphalting 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 Wax are subsequently removed from the deasphalted oil obtained in this way. The removal of aromatics from the de-asphalted oil may be carried out 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 resultant oil, which is known as bright stock waxy 'rafiinate; Dewaxing of the oil may be carried out by cooling the oil in the presence of a solvent. Dewaxing is preferably carried out with a mixture of methyl ethyl ketone and toluene at a temperature between 10 C. and 40 C. and a solventto-oil volume ratio between 1:1 and 10:1. The sequence in which the removal of aromatics. and wax from the deasphalted oil takes place is in principle arbitrary, but in order to minimize the volume of oil which is cooled during dewaxing, the dewaxing should preferably only be carried out after the aromatics have been removed from the de-asphalted oil. i

Preferably the wax used as a starting material will contain less than 35% by weight of oil. It is also preferred that the wax which is hydrocracked has been obtained from a de-asphalted lubricating oil fraction which after dewaxing at 30 C. has a viscosity index of at least'55 and in particular of at least 70. I 1

The hydrocracking catalysts which are used in the "process according to the invention are fluorine-containing sulfidic catalysts containing nickel and/or cobalt and in addition molybdenum and/ or tungsten on alumina as carrier. Preferred catalyst are those which contain 0.0250.8 gram atoms and in particular 0.05-0.7 gram atoms-ofnickel and/or cobalt and 0.05-0.5 gram atoms and in particular 0.1-0.4 gram atoms of molybdenum and/or tungsten per grams of alumina. The atomic ratio between nickel and/or cobalt on the one hand and molybdenum and/or tungsten on the other is preferably between 01:1 and 2:1, and in particular between 0.221 and 1.6: 1. i t

The metals may be incorporated into the present catalysts by any method known in the art for the preparation of catalysts containing several components ona carrier, for example by co-impregnation of alumina in one or more stages with an aqueous'solution containing salts ofthe metals concerned. The catalysts are used in sulfidic form. The catalysts may be sulfided by any method known in the art for the sulfiding of catalysts, for example by contacting the catalysts with a mixture of hydrogen and hydrogen sulfide or with hydrogen and a sulfur-containing hydrocarbon oil, such as a sulfur-containing gas oil.

In addition to the metals nickel and/or cobalt "and molybdenum and/or tungsten, the catalyst used in the process according to the invention should also contain fluorine.

The incorporation of fluorine into the catalysts may in principle be carried outin two manners. Flourine may be incorporated into the catalyst by impregnating the latter during or after the preparation 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 in an early stage of the hydrocracking process for which the catalyst is used (for example during or after the start-up of the process). In situ fluorination of the catalysts may be carried out by adding a suitable fluorine compound, such as o-fiuoro toluene or ditfluoro ethane, to the gas and/or liquid stream which is passed over the catalyst. In a number of cases it may be preferred to incorporate at least some of the fluorine in the catalyst by in situ fluorination. The quantity of fluorine contained in the present catalyst is preferably 0.5 to 7% by Weight'In addition to nickel and/or cobalt, molybdenum and/or tungsten and fluorine, the catalysts used in the process according to the invention may further contain promoters such as boron and phosphorus.

In the preparation of lubricating oil by hydrocracking of wax according to the invention, very favorable results are achieved by using one of the following catalysts.

(a) A catalyst prepared by impregnating alumina with a solution containing one or more nickel and/or cobalt compounds, one or more molybdenum and/or tungsten compounds, phosphate ions and peroxide ions, followed by drying and calcination of the composition.

"(b) A catalyst prepared by incorporating into an alumina hydrogel one or more nickel and/r cobalt compounds and one or more molybdenum and/or tungsten compounds in a suflicient concentration to impart to the finished catalyst a metal content, expressed as metal oxides of 30% to 65% by weight, followed by drying and calcination of the composition; the alumina hydrogel into which the metal compounds are incorporated should, after drying and calcination, yield a xerogel, i.e., the calcined hydrogel before metal compounds are added, with a compacted 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 composition containing alumina, water, one or more Water-soluble salts of nickel and/ or cobalt with one or more water-soluble salts of molybdenum and/ or tungsten, with a hydrogen sulfide-containing gas at a temperature below 150 C. and subsequently heating the material in a hydrogencontaining gas to a final temperature in excess of 200 C.; the quantity of water present in the composition which is treated with the hydrogen sulfide-containing gas should correspond with the quantity of water present in the composition after drying in a dry gas at 110 0., increased by 20% to 120% of the quantity of water which the dried composition can absorb in the pores of the carrier at 20 C.

The catalysts which are used in the hydrocracking process according to the invention preferably contain as catalytically active metal components nickel and molybdenum or nickel and tungsten.

The hydrocracking process should be carried out at a temperature between 325 C. and 425 C. and in addition under such conditions that 25% to 95% by weight of the resultant liquid reaction product consists of components having a boiling point in excess of 400 C. Suitable hydrocracking conditions are a pressure of 10 to 250 bar, a space velocity of 0.2 to kg. of feed per litre of catalyst per hour and a hydrogen/feed ratio of 100 to 5000 N1. of hydrogen per kg. of feed. The hydrocracking process is preferably carried out under the following conditions: a temperature of 360 C. to 415 C., a pressure of 25 to 200 bar, a space velocity of 0.5 to 1.5 kg. of feed per litre of catalyst per hour and a hydrogen/feed ratio of 500 to 2500 N1. per kg. of feed.

The wax is converted by hydrocracking into a liquid product, 25 to 95 wt. of which consists of components having a boiling point over 400 C. and the reaction product is separated by distillation into one or more light fractions and a residual fraction having an initial boiling point between 350 C. and 470 C. Preferably, the wax is converted by hydrocracking into a liquid product, 40% to 70% by weight of which consists of components having a boiling point in excess of 400 C. and a residual fraction having an initial boiling point between 390 C. and 450 C. is separated by distillation from the reaction product.

To prepare a suitable lubricating oil the residual fraction must be dewaxed. Dewaxing is preferably carried out by cooling the oil in presence of a solvent. Very suitable for this purpose is a mixture of methyl ethyl ketone and toluene at a temperature between 10 C. and -40 C. and a solvent-to-oil volume ratio between 1:1 and 10:1. In order to increase the yield of desired lubricating oil, it is preferred to recycle to the hydrocracking reactor at least a portion of the wax separated during dewaxing of the residual fraction of the hydrocracked product.

The process according to the invention enables lubricat ing oils to be prepared which as such, i.e., without additive having been incorporated therein, meet the 10W/ 30 specification. The process according to the invention moreover enables lubricating oils to be prepared which as such do not meet the 10W/30 specification, but from which in a simple manner, without the use of high molecular viscosity index improvers, a l0W/30 oil can be prepared by incorporating therein a certain quantity of an additive package. The commercial additive packages which are at present used in practice in the preparation of multigrade lubricating oils comprise a number of compounds each of which individually have the property that when they are incorporated in a lubricating oil they improve the quality of this lubricating oil in one or more respects. Examples of additives which are found in these additive packages are inter alia anti-oxidants, rust inhibitors, corrosion inhibitors, anti-wear agents, anti-foam agents, detergents, metal passivators and extreme pressure additives. In some cases, several quality-improving properties are combined in a single additive. If the lubricating oils prepared according to the invention are intended for use as motor oils, it is advisable to incorporate therein a certain quantity of additive package, even if the lubricating oil as such already meets the l0W/30 specification. In the preparation of 10W/30 oils according to the invention, it is preferred to incorporate such a quantity of the additive package in the base oil (which may or may not meet the 10W/3O specification) that an oil composition is obtained which comprises 87.5% to by weight of base oil and 5% to 12.5% of additives.

The invention will now be elucidated with reference to the following Examples.

'Example I Eight catalysts (A-H) were used in hydrocracking experiments to prepare lubricating oil from six residual waxes (I-VI). The catalyst and feeds are described in more detail below.

Catalyst A: Ni/Mo/F/Al O catalyst with a pore volume of 0.44 mL/g. and a specific surface area .of 117.1 m ./g. containing 6 parts by weight of nickel, 30 parts by weight of molybdeum and 7.5 parts by weight of fluorine per parts by weight of alumina. This catalyst had been prepared by co-impregnation of alumina with an aqueous solution of ammonium molybdate, nickel nitrate and ammonium fluoride. After the degree of wetting had been set at 100%, the composition was first treated for 16 hours with H 8 at 15 bar and 75 0., subsequently heated in 2 hours to 400 C. in a stream of H S-containing H (9% v. H 8, 10 bar, 25,000 N1. 1*. hour and finally kept for approximately 2 hours in this gas stream. The expression degree of wetting used above relates to the quantity of water present in the composition in addition to the quantity of water which is present therein after drying of the composition in a"dry- 'ing gas at 110 C. The degree of wetting is expressed 'as'a percentage of the quantity of water which the dried composition can absorb in the pores of the carrier at 20 C.

Catalyst B: Ni/Mo/F/Al O; catalyst with a pore volume of 0.23 nil/g. and a specific surface area of 63.0

mL /g. containing 6 parts by weight of nickel, 30 parts by weight of molybdenum and 7.5 parts by weight of fluorine per 100 parts by weight of alumina. This catalyst was prepared in the same way as catalyst A except that another type of alumina was used.

Catalyst C: Ni/W/F/AI O containing parts by weight of nickel, 38 parts by weight of tungsten per 100 parts by weight of alumina and 2.4% by weight of fluorine. This catalyst was prepared in the same manner as catalysts A and B, except that a fluorine-free impregnation liquid was used which contained ammoniumtungstate and nickel nitrate and that fluorine was incorporated into the catalyst by fluorination in situ.

Catalyst D: Ni/Mo/P/Al 0 catalyst containing 4.2 parts by weight of nickel, 17.7 parts by weight of molybdenum and 3.1 parts by weight of phosphorous per 100 parts by weight of alumina and 1.6% by weight of 'fiuorine. This catalyst was prepared by co-impregnation of alumina with an aqueous solution containing nickel nitrate, phosphoric acid, ammonium molybdate and hydrogen peroxide, followed by drying and calcination of the composition. Fluorine was incorporated intothe catalyst by fluorination in situ.

Catalyst E: Ni/W/F/Al O catalyst containing 31 parts by weight of nickel, 58 parts by weight of tungsten and 7.5 parts by weight of fluorine per 100 parts by weight of alumina.

Catalyst F: Ni/W/F/Al O catalyst containing 31 parts by weight of nickel and 58 parts by weight of tungsten per 100 parts by weight of alumina and 6% by weight of fluorine.

Catalyst G: Ni/W/F/Al O catalyst containing 37 parts by weight of nickel and 70 parts by weight of tungsten per 100 parts by weight of alumina and 4.3% by weight of fluorine.

The catalysts E, F and G were prepared by mixing an alumina hydrogel with an aqueous solution containing nickel nitrate, ammonium tungstate and ammonium fluoride, the pH of which solution had been brought to 6.5 with the aid of 25% of ammonia. The mixture was heated to 80 C.; the gel was filtered, extruded, dried and calcined. After drying and calcining, the alumina hydrogel used in the preparation of these catalysts yielded a xerogel with a compacted bulk 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 O catalyst containing 10 parts by weight of nickel and 60 parts by weight of tungsten per 100 parts by weight of alumina and 4.5% by weight of fluorine. This catalyst was prepared by coimpregnation of alumina with an aqueous solution containing nickel nitrate and ammonium tungstate and subsequent drying and calcination. Fluorine was incorporated obtained after the wax had been deoiled: 97. Sulfur content of the wax: 0.34% by weight.

Feed 11 (DOA slack wax): Wax obtained in dewaxing Iaresidual lubricating oil fraction (1) which had previously been deasphalted with' propane. Initial boiling point of the wax: 520 C. Oilcontentof the wax: 9.8%

by weight. VI of the oilobtained after deoiling the wax:

'78. Sulfur content of the wax: 0.85% by weight; I

tracted with furfural. Initial boiling point of the wax:

520 C. Oil content of the wax: 21.1% by weight. VI of the oil obtained after the wax had been deoiled: 98. Sulfur content of the Wax: 0.66% by weight.

Feed IV (Wax from hydrocracked bright stock slack Wax): Wax obtained in dewaxing a residual fraction of a hydrocrackate which had been prepared "by hydrocracking of wax obtained in dewaxing. a residual lubricating oil fraction (1) which hadpreviously been deasphalted with propane and extracted with furfural. Initial boiling point of the feed wax: 390 C. Of this wax 92.5% by weight boiled above- 520C. Oil content of the feed wax: 6% by Weight. V -I-"of the oil obtained after the feed wax had been deoiled:.l49. Sulfur .content of the feed wax; 20 p.p.=m.w.

Feed V (Wax from hydrocracked bright stock slack wax): Wax obtained in dewaxing a residual fraction of a hydrocrackate which had been prepared by hydrocracking of wax obtained indewaxing a residual lubricating oil fraction (1) which had previously been deasphalted with propane and extracted with furfural. Initial boiling point of the feed: 520 C. Oil content of, the feed wax: 7% by weight. VI of the oil obtained after the feed wax had been deoiled: 150. Sulfur content of the feed wax: 20 p.p.m.w.

Feed VI (Wax from mildly hydrocracked DAO): Wax obtained in dewaxing a residual fraction of a hydrocrackate which had been prepared by mildly hydrocracking (25 by weight of the hydrocrackate boiled below the initial boiling point of the feed) of a residual lubricating oil fraction (1) which had previously been deasphalted with propane. Initial boiling point of the feed wax: 520 C. Oil content of the feed wax: 21% by weight. VI of the oil obtained after the feed was deoiled: 95. Sulfur content of the feed wax: 500 p.p.m.w.

The six residual lubricating oil fractions from which the feeds I-VI were prepared had been obtained as residue during distillation various parafiinic crude oils. Dewaxing was carried out by cooling the oil to a temperature of -30 C. in the presence of a 1:1 mixtur of methyl ethyl -ketone and toluene.

The viscosity indices mentioned in this patentapplication were determined by ASTM standard D 2270.

Example 2 The hydrocracking experiments 126 were carried out under the following conditions:

pressure: 150 bar, except for experiment'7; this experiment was carried out at a pressure of 50 bar.

temperature: 3754l0 C.- 1

space velocity: 11.l- .hour

hydrogen/feed ratio: 2000 Nl.'l"'

catalyst bed: ml.

The catalysts were used in the sulfidic form. Sulfiding of the catalysts D-G was carried out by contacting them with hydrogen and a sulfur-containinggas oil. From the hydrocracked products, residual fractions having an initial boiling point between 365 C. and 440 C. were separated by distillation. From the residual fractions the corresponding lubricating oils were prepared by dewaxing the fractions. 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.

The results of the hydrocracking experiments 1-26 are shown in Table A. Y

TABLE A Quantity of material I 1 boiling Initial boil- Properties of the dewaxed residual lubricating above 400 ing point of w oil traction 0. present in the separa- Hydrothe liquid ted residual Kinematic Dynamic cracking reaction lub. oil Yield based viscosity viscosity temp products traction, on feed, at 98.9 0., at 17.8 0., percent wt. percent wt. VI cst. v P.

The experiments 1-26 shown in the Table A are all 'hydrocracking experiments according to the invention.

Each of these experiments yields more than 15% wt., based on the feed, of a lubricating oil having a dynamic viscosity of at most '24 P at 17.8 C. and a kinematic viscosity of at least 7.0 cst. at 98.9 C. The lubricating oils prepared according to the experiments 1 11 meet the 10W/30 specification (dynamic viscosity at 17.8 C. at

TABLE B Properties of a composition Properties of a composition comprlslng 92.5% wt. of the comprising 89.9% wt. of the Properties of the base oil base oil and 7.5% wt. of the base oil and 10.1% wt. of the without additive package additive package A additive package B Kinematic Dynamic Kinematic Dynamic Kinematic Dynamic viscosity viscosity viscosity viscosity viscosity viscosity Base oil prepared at 98.9 C. at 17.8 C. at 98.9 C., at 17.8 0., at 98.9 0., at 17.8 0., according to exp. No. VI est. P. est. P. cst. P,

least 12 P and at most 24 P and kinematic viscosity at The results given in Table B show that lubricating oils 98.9 C. at least 9. 6 est. and at most 12.9 cst.) as such, prepared according to the invention which as such do not i.e., without the incorporation of additives. meet the 1OW/30 specification (compare exp. 12-23) may be formulated to 10W/ 30 oils in a simple manner, Example 3 Without the addition of the customary high-molecular An additive package was incorporated in the lubricatg vlsc'osrty lmPmYers by the incorporation fi ing oils prepared according to the experiments 12-23 addmvefiwkage A.or.B'In.corpOrat'1On of addmve which do not meet the 10W/30 specification and in the P g m lubncatmg O11 prepared accordmg. to lubricating oils prepared according to the experiments mven'tlon Whlch already {meets the low/30 fqpeclfioatlon 8 and 11 which do meet the 10W/30 specification. Two (comm 8-11) yelds low/30 011 of b additive packages were used, designated as additive pack- E 1 age A and additive package B. These additive packages Xamp e 4 differ as regards the chemical composition of the addi- In the process according to the invention it is essential tives which they contain but both have substantially the that a fluorine-containing sulfidic catalyst be used which same effect, namely: anti-oxidation, rust-inhibition, wear contains nickel and/or cobalt and in addition molybresistance, corrosion inhibition, foam inhibition, metal denum and/or tungsten on alumina as carrier. To demonpassivation, improvement of the lubricating effect as strate the importance of fluorine a Ni/MO/ P/AI O catahlgh pressure and inhibition of deposits in the engine. lyst containing 4.2 parts by weight of nickel, 17.7 parts by weight of molybdenum and 3.1 parts by weight of phosphorous per 100 parts by w'e'ight'of'alurnina tcatalyst D without fluorine) was used for hydrocracking feed I.

without the addition of a polymeric viscosity index improver which"comprisesr'dewaxinga de-asph alted residual mineral oil fraction; ,obtaining a wax therefrom, more manner as in experiment 3. Table C compares the results I;

of experiment 27 with those of experiment -3'.'

The results shown in Table C demonstrate the unsuitability of the fluorine-free catalyst for the present purpose. At a hydrocracking temperature of 394 C., the fluorinecontaining catalyst gives a lubricating oil yield of 27% by weight; at a hydrocracking temperature of 445 C.,

the fluorine-free catalyst gives a lubricating oil yield of only 12% by weight.

Example 5 I To demonstrate the importance of using alumina as a carrier, a Nl/W/P/SlO'g-AIZOQ catalyst containing 9% by weight of nickel, 17% by weight of tungsten and 2.5% by weight of fluorine on a carrier which comprised 26% by weight of alumina and the remainder being silica, was used for hydrocracking wax obtained during dewaxing of a residual lubricating oil fraction de-asphalted with propane (VI of the deasphalted oil after dewaxing at -19 C.':77). The residual lubricating oil fraction from which the wax (-DAO slack wax) was prepared had been obtained during distillation under reduced pressure of an atmospheric distillation residue 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 with the use of the catalyst in the sulfidic form at a temperature of 350 C., a pressure of bar, a space velocity of 1kg. 1- hour-- and a hydrogen/feed ratio of 150 NL/kg. of oil.

From the hydrocracked product a residual fraction with an initial boiling point of 400 C. was separated by distillation and dewaxed by cooling the oil at a temperature of 27 C. in the presence of a 1:1 mixture of methyl ethyl ketone and toluene. The result was 'a dewaxed residual lubricating oil fraction in a yield of 20% by weight, based on feedIhaVing a VI of 100,; kinematic viscosity at 98.0 C. of 16.9 cst. and a dynamic viscosity at 17.8 C. in excess of 200 P. These results demonstrate the unsuitability of a silica-alumina based catalyst for the present purpose since a 10W/3O oil cannot be prepared from the lubricating oil even by incorporating an additive package.

What is claimed is:

1. A process for preparing at least 15% wt. basis feed of a l0W/30 grade lubricating oil having a dynamic viscosity of at least 12 P and at most 24 P at '17.8 C. and a kinematic viscosity of at least 7.0 cst. at 98.9 C.

. crack-in'ga feedstockcorisistin g of said wax in the presence of a ca't'alyst consisting of a catalytic amount of at least l one metalsulfide selected from the group consisting. of

nickel and cobalt and of atleast one metal sulfide selected from the group consisting of molybdenum 'and' tungsten supported on a fluorine-containing alumina at a temperature between 325C. and 425 C. and under conditions to form'a liquid product containing 2595%p wt. of components havinga boiling, point over 400 C.; separating said liquid product by distillation into at least one light fraction and a residual fraction having an initial boiling point between 350 C. and 470 C.; dewax-ing said residual reaction and recovering said 10W/ 30 grade lubricating oil.

2. The process of claim 1 wherein the aromatics have been removed from the de-asphal'ted residual oil fraction prior to dewaxing. f

3. The process of claim 2 wherein the wax which is hydrocracked contains less than 35% wt. of oil.

4. The process of claim 2 wherein the wax which 'is hydrocracked has been obtained from a de-asphalted lubricating oil fraction which after dewaxing at 30 C. has a viscosity index of at least 55. V

5. The process of claim 1 wherein 'the catalyst contains 0.025 to 0.8 gram atoms of nickel and/or cobalt and 0.05 to 0.5 gram atoms of molybdenum and/or tungsten per 100 grams of alumina.

6. The process of claim 4 wherein the atomic ratio between nickel and/or cobalt on the one hand and molybdenum and/or tungsten on the other is between 01:1 and 2: 1.

7. The process of claim 1 wherein the catalyst contains 0.5 to 7-%-wt. of fluorine.

8. The process of claim 1 wherein the catalyst contains nickel and molybdenum or nickel and tungsten as catalytically active metal components.

9. The process of claim 1 wherein the hydrocracking process conditions include a pressure from 10 to 250 bar, a space velocity of 0.2 to 5 kg. of feed per litre of catalyst per hour and a hydrogen/feed ratio of 100 to 5000 N1. of hydrogen per kg. of feed.

10. The process of claim 1 wherein the wax is converted by hydrocracking into a liquid product containing 40% to wt. of components having a boiling point over 400 C. and the residual fraction separated by distilla-tion has an initial boiling point between 390 C. and 450 C.

11. The process of claim 1 wherein a lubricating oil is prepared which meets the 10W/ 30 specification without additives having been incorporated therein.

Primary Examiner US. Cl. XJR- HERBERT LEVINE,