US3112259A

US3112259A - Refining of lubricant oils

Info

Publication number: US3112259A
Application number: US22085A
Authority: US
Inventors: Grawitz Jacques
Original assignee: Compagnie Francaise de Raffinage SA
Current assignee: Compagnie Francaise de Raffinage SA
Priority date: 1959-04-14
Filing date: 1960-04-14
Publication date: 1963-11-26
Anticipated expiration: 1980-11-26
Also published as: FR1232363A; GB910931A; BE589687A

Description

United States Patent 3,112,259 REFINING 0F LUBRICANT OILS Jacques Grawitz, Le Havre, France, assignor to Societe Anonyme dite: Compagnie Francaise de Raflinage,

Paris, France, a corporation of France N0 Drawing. Filed Apr. 14, 1960, Ser. No. 22,085

Claims priority, application France Apr. 14, 1959 Claims. (Cl. 208-264) It is known that the production of lubricating oils entailing extraction by means of solvents and the removal of paraffin necessitates a final treatment by means of absorbent substances, such as activated earths, in order to improve the color of the commercial products and give them good stability. This treatment by means of decolorizing earths has a number of drawbacks, however; it necessitates very large installations; the discharge of the used earths ultimately presents a difficult problem; and it involves a loss of advantageous products, the used earths being highly impregnated by the treated products when it is necessary to discard them.

Other finishing processes have been proposed to obviate these drawbacks, and more especially catalytic refining processes in the presence of hydrogen.

The present invention relates to an improved method of catalytic treatment for lubricating oils obtained from the distillates of petroleum products, in order to improve the odor, color and stability of the commercial products.

.This method comprises bringing the oily distillates, which have preferably been previously refined by solventextraction and from which the parafiin has preferably been previously removed, into contact, in the presence of hydrogen, with a particularly effective catalyst (which will be indicated hereinafter), and in operating under conditions such that there is practically no reduction of the sulfur compounds present in the treatedv oil, because it has been found that these, acting as natural inhibitors, have a favorable action as regards the stability of the finished products.

Furthermore, it is known that the usual hydro-desulfurizing catalysts are oxides or sulfides of cobalt and molybdenum, free or combined, deposited on porous supports.

The applicant, however, has observed that if these catalysts are used for a refining treatment aimed more especially at decolorizing and stabilization of lubricating oils and requiring very selective hydrogenation conditions, which do not alfect the sulfur compounds, and at temperatures substantially lower than those required'for the desulfurizing of lighter products than oils, the results can be greatly improved by an improvement of the technique, this improvement being the subject of the present invention.

According to the invention, there is used for the hydrorefining of oils in the presence of hydrogen a selective hydrogenation catalyst containing oxides of metals of the VIth group and of the VIIIth group, which are deposited on oxides of metals of the IIIrd and IVth group or of the IInd group, which catalyst has been subjected, in the presence of hydrogen, to the prior action of a petroleum distillate rich in sulfur, selected, for example, from the range of distillation of gas oils or lamp-oils.

The following examples illustrate this technique, and show the superiority of the latter over previous processes.

EXAMPLE I Two catalysts on the basis of molybdenum oxide and cobalt oxide, one of which is deposited on activated alumina and the other on magnesia, were tested.

In a first operation, the furnaces charged with each of these catalysts were fed with an oily distillate of a viscosity of 33.7. centistokes at 210 F. after refining with furfural and removal of parafiin; the treatment was 3,1 12,259 Patented Nov. 26, 1963 carried out at 350 C. under 30 kg. per square centimeter pressure with a feed rate of 5 v./v./h. (volume of charge per hour and for 1 volume of catalyst) and a hydrogen recycle of 355 cubic meters per cubic meter of charge. (See below: tests I and III.)

In a second operation, the furnaces charged with the same catalysts were fed in the first instance with a gas oil containing 1.2% of total sulfur at the rate of 3 volumes per volume of catalyst and per hour, at 400 C., under a pressure of 30 kg. per square centimeter with a hydrogen recycle of 500 cubic meters per cubic meter of gas oil; this treatment was continued for 12 hours. After this first treatment, the supply of gas oil is discontinued and the oily distillate identical to that of the preceding test is injected at a rate of 5 v./v./h. after the temperature has been lowered to 350 C. and the hydro gen recycle brought to 355 cubic meters per cubic meter of oily distillate (tests II and IV). The results of these twoseries of tests are given in Table I, which shows the advantage of the pre-treatment in the qualities of the color and stability of the oils obtained in comparison with the treatment on the corresponding catalyst which has not undergone this pre-treatrnent.

EXAMPLE II A catalyst obtained by making a paste of heavy magnesia with an ammoniacal solution of cobalt molybdate has the following composition after drying at 400 C.:

Percent MgO 88 M00 10 C00 2 An oily distillate refined with furfural and from which the parilfin has been removed, and the viscosity characeristics of which at 210 F. are 12.3 centistokes, is treated on this catalyst.

The treatment is carried out at 350 C. under 30 kg. per square centimeter pressure with a rate of feed of 8 v. v./ h. and a hydrogen recycle of 355 cubic meters per cubic meter of charge.

After 48 hours operation on this catalyst, a sample of the product obtained is analyzed. The catalyst is then activated, the furnace being fed with a batch of illuminating oil containing 0.170% of total sulfur, at the rate of 4 volumes per volume of catalyst per hour, the temperature being increasedto 370 C., and the hydrogen recycle being raised to 400 cubic meters per cubic meter of, gas .oil. The illuminating oil treated now contains only 0.008% of sulfur. After 10 hours operationunder these conditions .the oily distillate is again supplied, the initial operating conditions being restored.

Comparison of the qualities of the products obtained will be clear from Table II.

An oily distillate, refined by extraction with furfural and removal of the parafiin, of a viscosity of 8.62 centistokes at 210 F., is treated on a catalyst containing oxides of molybdenum and cobalt deposited on magnesia. The treatment is carried out at 310 C. under 30 kg. per square centimeter pressure at a rate of feed of 8.5 v./ v./ h. and a hydrogen recycle of 235 cubic meters per cubic meter of charge.

After 48 hours operation on this catalyst a sample of the product obtained is analyzed, and activation of the catalyst is then effected, the reactor being fed with a gas oil containingfi 1.2% of sulfur at 400 C. under 30 kg. per square centimeter pressure at a rate of feed of 5 v./v./h.; the treatment conditions being such that the sulfur content of the gas oil is brought to 0.10%

After 15 hours of this activation treatment the supply of gas oil is discontinued, and paraffin distillate is again treated under the same conditions as in the first stage.

After 48 hours of operation the product obtained is again analyzed.

The qualities of the products treated are apparent from Table III.

A catalyst comprising nickel tungstate deposited on an alumina and silica support is used for the hydro-refining of an oily distillate as in Example II. The results are apparent from Table IV.

Table IV Product treated on- Fresh charge Initial catalyst, Ni Pre-treated tungstate Catalyst +A120a +Sin Duration, hours 50 50 D 15 0.8886 0.8870 0. 8868 12.34 12.38 12. 40 8 3% In the industrial application of the process, it has been found that the advantage of the pre-treatment according to the present invention is maintained during the entire life of the catalyst, the improved activity of which is retained for a practically unlimited time.

On the other hand, the catalyst which has not undergone any pre-treatment in no way improves with the period of use under the operating conditions obtaining in the hydro-refining of oils.

What I claim is:

1. In a process for the finishing treatment of refined lubricating oil fractions to improve the odor and color and stability thereof by catalytic action of hydrogen without affecting substantially the sulphur content of said fractions, the steps which comprise providing a catalyst for said catalytic hydrogen action including an oxide of a metal selected from groups VI and VIII of the periodic table, said metal oxide catalyst being deposited on a supporting material therefor including an oxide of a metal selected from groups II and III and IV of the periodic table, activating and enhancing the effectiveness of said catalyst in a pre-treating step by subjecting said catalyst on said supporting material in the presence of hydrogen to the action of a petroleum distillate different from said lubricating oil fractions and including a substantial proportion of reactive and removable sulfur with consequent removal of sulfur from said petroleum distillate, and thereafter subjecting said lubricating oil fractions to the action of hydrogen in the presence of said thus activated and enhanced catalyst effecting said finishing improvement in the odor and color and stability of said fractions substantially in the absence of sulfur removal therefrom.

2. In a process for the finishing treatment of refined lubricating oil fractions to improve the odor and color and stability thereof by catalytic action of hydrogen thereon without affecting substantially the sulfur content of said fractions, the steps which comprise providing a catalyst for said catalytic hydrogen action including an oxide of at least one metal selected from groups VI and VIII of the periodic table, said metal oxide catalyst being deposited on a supporting material therefor including an oxide of at least one metal selected from groups II and III and IV of the periodic table, activating and enhancing the effectiveness of said catalyst in a pre-treating step by subjecting said catalyst on said supporting material in the presence of hydrogen to the action of a petroleum distillate including a substantial proportion of sulfur, and there after subjecting said lubricating oil fractions to the action of hydrogen in the presence of said thus activated and enhanced catalyst effecting said finishing said fractions substantially in the absence of sulfur removal therefrom.

3. In a process for the finishing treatment of refined lubricating oil fractions to improve the odor and color and stability thereof by catalytic action of hydrogen thereon without aflecting substantially the sulfur content of said fractions, the steps which comprise providing a catalyst for said catalytic hydrogen action including an oxide of a metal selected from groups VI and VIII of the periodic table, said metal oxide catalyst being deposited on a supporting material therefor including an oxide of a metal selected from groups 11 and III and IV of the periodic table, subjecting said catalyst on said supporting material to a pre-treating step in the presence of hydrogen to the action of a petroleum distillate including a substantial proportion of sulfur, and thereafter subjecting said lubricating oil fractions to the action of hydrogen in the presence of said thus pre-treated catalyst effecting said finishing said fractions.

4. A method as recited in claim 3 in which said petroleum distillate utilized in said pre-treating step for said catalyst is within the distillation range of kerosene and gasoline and contains about 0.5% to 2% total sulfur.

5. A process as recited in claim 3 in which said pretreating step for said catalyst is effected in a temperature range of about 360 C. to 420 C., and with removal of about 70% to 95% of the sulfur in said petroleum distillate.

6. A process as recited in claim 3 in which said finishing treatment of said lubricating oil fractions is elfected at a temperature of about 250 C. to 360 C.

7. A process as recited in claim 3 in which said catalyst comprises molybdenum and cobalt oxides and said supporting material comprises alumina.

8. A process as recited in claim 3 in which said catalyst comprises molybdenum and cobalt oxides and said supporting material comprises magnesia.

9. A process as recited in claim 3 in which said catalyst comprises cobalt molybdate and said supporting material comprises alumina.

10. A process as recited in claim 3 in which said catalyst comprises cobalt molybdate and said supporting material comprises magnesia.

References Cited in the file of this patent UNITED STATES PATENTS 2,706,167 Harper et a1 Apr. 12, 1955 2,878,180 Watkins Mar. 17, 1959 2,904,505 Cole Sept. 15, 1959 2,921,025 Holm et al Jan. 12, 1960 2,936,281 Annable et a1. May 10, 1960 2,967,144 Cole Jan. 3, 1961

Claims

1. IN A PROCESS FOR THE FINISHING TREATMENT OF REFINED LUBRICATING OIL FRACTIONS TO IMPROVE THE ODOR AND COLOR AND STABILITY THEREOF BY CATALYTIC ACTION OF HYDROGEN WITHOUT AFFECTING SUBSTANTIALLY THE SULPHUR CONTENT OF SAID FRACTIONS, THE STEPS WHICH COMPRISE PROVIDING A CATALYST FOR SAID CATALYTIC HYDROGEN ACTION INCLUDING AN OXIDE OF A METAL SELECTION FROM GROUPS VI AND VIII OF THE PERIODIC TABLE, SAID METAL OXIDE CATALYST BEING DEPOSITED ON A SUPPORTING MATERIAL THEREFOR INCLUDING AN OXIDE OF A METAL SELECTED FROM GROUPS II AND III AND IV OF THE PERIODIC TABLE, ACTIVATING AND ENHANCING THE EFFECTIVENESS OF SAID CATALYST IN A PRE-TREATING STEP BY SUBJECTING SAID CATALYST ON SAID SUPPORTING MATERIAL IN THE PRESENCE OF HYDROGEN TO THE ACTION OF A PETROLEUM DISTILLATE DIFFERENT FROM SAID LUBRICATING OIL FRACTIONS AND INCLUDING A SUBSTANTIAL PROPORTION OF REACTIVE AND REMOVABLE SULFUR WITH CONSEQUENT REMOVAL OF SULFUR FROM SAID PETROLEUM DISTILLATE, AND THEREAFTER SUBJECTING SAID LUBRICATING OIL FRACTIONS TO THE ACTION OF HYDROGEN IN THE PRESENCE OF SAID THUS ACTIVATED AND ENHANCED CATALYST EFFECTING SAID FINISHING IMPROVEMENT IN THE ODOR AND COLOR AND STABILITY OF SAID FRACTIONS SUBSTANTIALLY IN THE ABSENCE OF SULFUR REMOVAL THEREFROM.