US2985586A - Hydrofining of lubricating oil fractions - Google Patents

Description

y 1961 D. H. WILLSON ET AL 2,985,586

HYDROFINING OF LUBRICATING OIL FRACTIONS Filed NOV. 26, 1958 HYDROGEN x} ADDITlVE 3O 38 HYDROGEN REACTION 39 SULFIDE ZONE 3| 34 IB- TL LUBRICATING 7 4| on. ,4,2O SEPARATION 35 33 HEATER ZONE 2 54 36 FRACTION/AL LUBSIIEATING DISTILLATION FRACTION ZONE aun gzns 2| EFFECT OF WEIGHT PER CENT SULFUR AND HYDROFINING TEMPERATURE ON AVERAGE BEARING WEIGHT LOSS AND PISTON SKIRT VARNISH FOR PANHANDLE ISO-NEUTRAL OIL l I I l 5.4 l 0.4

5.0 0.0 O .04 .08 .l2 .l6 .20 .24 .26 .32

WEIGHT PER CENT SULFUR DAN H. WILLSON, GEORGE R. L. SHEPHERD,

AT OR United States Patent HYDROFINING OF LUBRICATING OIL ERA'CTIONS Filed Nov. 26, 1958, Ser. No. 781,419

- 7 Claims. (Cl. 208264) The present invention is directed to hydrofining of lubricating oil fractions. More particularly, the invention is concerned with treating a lubricating oil fraction in the presence of hydrogen to form an improved lubricant. In its more specific aspects, the invention is concerned with the formation of a lubricating oil which contains sulfur. Y e

The present invention is directed to the production of improved lubricating oil in which a lubricating oil fraction is hydrofined in the presence of a sulfur-resistant catalyst at 'a-tem'perature within the range from about 400 to about 650 F. under a pressure within the range from about 200 to about 1,000 pounds per square inch and at a space velocity within the range from about 1 to; Y

about 10 v./v./hr. in the presence of sufficient free by: drogen-containing gas to provide from about 50 to about 5,000 standard cubic feet of hydrogen per barrel of the lubricating oil fraction, the hydrogen-containing gas also containing from about 5% to about 95% by volume of hydrogen sulfide to form a product containing sulfur and of improved lubricating quality.

The feed stock employed in the present invention is a lubricating oil fraction which may boil in the'range from about 800 to about 1,200" F. and ordinarily will comprise a fraction of crude petroleum. Higher boiling fractions may also be used. Such lubricating oil fractions are known as neutral oils, light motor oils, medium motor oils, and bright stocks. It is contemplated that the lubricating oil fraction employed in the present invention may suitably be a solvent ralfinate of a lubricating oil fraction obtained from crude petroleum. Examples of the crude petroleum from which the lubricating oil fraction may be obtained are the Gulf Coastal crudes, Panhandle crudes, Pennsylvania type crude oils, and California crude oils and the like.

The invention is suitably practiced with a suitable sulfur-resistant catalyst, of which many are known to the,

art. As examples of suitable catalysts are the oxides and sulfides of metals such as vanadium, chromium, manganese, iron, cobalt, nickel, molybdenum, tungsten, and the like. Specific examples of such catalysts are cobalt molybdate, nickel-tungsten sulfide, cobalt sulfide, molybdenum sulfide, molybdenum oxide, nickel sulfide, tin sulfide, and the like. The catalysts are preferably employed on a support or a suitable carrier such as alumina, magnesia, silica, zirconia, spinels, and the like. The catalyst may be employed as a fixed bed catalyst, in the form of a fluidized bed, or as a slurry in the lubricating oil, or

in any other suitable manner.

The present invention is suitably conducted in the lpresence of hydrogen, and an amount of hydrogen within the range from about 50 to about 5,000 standard cubic 'feet per barrel is employed. A preferred amount of hydrogen is from about 65 to about 500 standard cubic feet per barrel. The hydrogen for the operation is provided by charging a hydrogen-containing gas to the catalyst along with the feed stock. The hydrogen-containing gas may be added from an extraneous source and may be pure hydrogen or may comprise a mixture of hydro- 2,985,586 Patented May 23, 1961 ice gen and gaseous material such as light hydrocarbons. For example, gaseous material from the operation may provide at least a part of the hydrogen-containing gas as a source of the hydrogen for the reaction.

The amount of hydrogen sulfide which is added with the hydrogen is within the range from about 5% to about by volume of the total gas with a preferred range from about 20% to about 70% by volume based on the total gas. In the present invention the hydrogen sulfide may largely be provided from an extraneous source since ordinarily the amount of hydrogen sulfide provided in a hydrofining operation is not suflicient for best results. However, recycle of tail gas may provide suflicient hydrogen sulfide build up.

The temperatures employed in the practice of the present invention may suitably range from about 400 to about 650 F. with desirable results being obtained at about 500 F. A preferred temperature range is from about 475 to about 575 F.

Pressures may suitably range from about 200 to about 1,000 pounds per square inch with good results being obtained at about 750 pounds per square inch. A preferred range is from about 400 to about 800 pounds per square inch.

The space velocity may range from about 1 to about 10 volumes of feed per volume of catalyst per hour with a, preferred space velocity from about 3 to about 5 In accordance with the present invention, improved results are obtained in that the present invention provides a lubricating oil product which .contains sulfur in an amount greater than that usually present in a hydrofined lubricating oil product. The presence of sulfur confers unusual properties on the lubricating oil in that in the present invention the response of the product to lubricating oil additives and inhibitors is enhanced. In other words, for a given amount of a lubricating oil additive or inhibitor, a greater response is had with the product of the present invention that with a conventionally hydrofined product. Furthermore, the product hydrofined according to this invention performs more satisfactorily than conventionally hydrofined products without inhibitors. This means that with the present invention, amounts of additives can be reduced and yet obtain beneficial results.

The present invention will be further illustrated by reference to the drawing in which:

Fig. 1 is a flow diagram of a preferred mode of practicing the invention, and

Fig. 2 is a graphical presentation of data showing the elfect of sulfur and hydrofining temperature on bearing weight loss and piston skirt varnish for a Panhandle neutral oil.

Referring now to the drawing and particularly to Fig. 1, numeral 11 designates a charge line by way of which a lubricating oil fraction is introduced into the systemtion only, a neutral or light motor oil is charged. Introduced intoline, 11 by line 12 is a hydrogen-containing gas in which hydrogen sulfide is suitably added by way of line 13 controlled byvalve 14. v The mixture of hydrogen, hydrogen sulfide, and lubricating oil is suitably introduced into a heater 15' provided with a heating coil 16 and with burners such as gas burners 17, by way of which the temperature of the mixture is raised to a temperature within the range given before. The heated mixture, under the conditions setout herein, is discharged from heater '15 by line 18 and introduced thereby into a reaction zone 19 containing a bed of catalyst 20 such as cobalt molybdate. Under the conditions for the practice of this invention, the lubricating oil fraction is suitably hydrofined and a product is formed which is withdrawn by line 21 34, 35, and 36 for withdrawal and recovery of the lubricating oil fractions. Line 37 is provided for discharge of heavier fractions which may be of bright stock quality. It will be understood, however, that when one of the and discharged thereby into a separation zone 22, which components of the total lubricating oil fraction is charged,

is of suitable capacity to provide a residence time for separation of normally gaseous products from the liquid products, the gaseous products being withdrawn from separation zone 22 by line 23 for recycling to line 12 zone 28 may be used only to remove light ends and to recover the desired productthrough line 37 with lines 31, 32, and 33 being closed. While the inhibitor may be added directly to the distilled product, the inhibitor by branch line 24 controlled by valve 25. This recycled is preferably added to the final blended motor oil.

gas provides at least a portion of the hydrogen and may provide a portion of the hydrogen sulfide for the process. A portion of the gas may suitably be discharged from line 23 by manipulation of valve 26.

Since the product of this operation has enhanced response to lubricating oil additives or inhibitors, provision is made for adding a lubricating oil additive by way of manifold 38 which connects into lines 31, 32, and 33 and When the total lubricating oil fraction is charged, the into which flow is controlled by way of valves 39, 40,

liquid products from Zone 22 are withdrawn therefrom by line 27 and introduced into a fractional distillation zone 28, which is shown as a single fractional distillation tower but which may be a plurality of fractional distiland 41 as may be desired. Where a selected oil such as neutral oilis hydrofined and withdrawn by line 37, inhibitor may be added thereto as desired.

If the recycled gas does notprovide suflicient hydro lation towers, each equipped with all auxiliary apparatus gen, this may be provided from an extraneous source by usually incident to a modern fractional distillation tower. Thus, zone 28 is provided with suitable internal, vaporliquid contacting means, cooling and condensing means, means for inducing reflux and the like, not shown. Zone opening valve 42 in line 12. v

In order to illustrate the present invention'further, a number of hydrofining runs were made employing Panhandle l50-neutral raffinate, Panhandle light motor oil 28 is equipped with a heating means 29, illustrated by rafiinate, and Panhandle 150-'X bright stock raffinate a steam coil, for adjusting temperature and pressure for distillation of the liquid product. Line is provided for removal of light fractions boiling above lubricating oil and lines 3-1, 32, and 33 controlled, respectively, by valves using 10 to 20 mesh cobalt molybdate as a catalyst.

The following table I sets out the several conditions and the product inspections resulting from the hydrofining operations.

TABLE I Hydrofimng conditions and product mspectzons Type of Catalyst Cobalt Molybdate, 10-20 Mesh Run Number Feed 465 Feed 474 476 476 477 478 498 499 Feed; 7 527- 528 3 529 Feed Stocks Panhandle ISO-Neutral Raflinate' Reactor Temperasure, F 475 .Q 500 500 475 475 550 575 550 Reactor Pressure, P s i Q 300 750 750 700. 700 700 750 750 Feed Rate, v./v./Hr 3. 1 3. 2 3.1 3. 2 3. 2 3. 2 4. 8 3.2 Total Gas Rate, s.c.f./Hr 27 24 26 26 24 30 23 23 Hydrogen Sulfide Injected, Volume Percent of Total G 11 5 11 1O 5 22 68 79 Hydrogen Gas:

Volume Percent of Total Gas 89 95 89 90 95 78 32 21 S.c.t./Bb1. Feed 342 337 345 340 339 339 71 72 Product Inspections:

Gravity, API 33. 2 33. 3 32. 4 32. 6 32. 6. 32. 6 32. 6 32. 7 32. 7 33-1 Flash, 0.0. F 400 415 430 425 425 425 42 410 420 410 Viscosity, SSU/IONF--- 139 6 137.7 148.0 146 3 146 1 146.5 146.4 146 2 146 4 139.7 Viscosity, SSU/210 F-.. 42 9 42.8 43.4 43 2 43 3 43.3 43.2. 43 3 42.8 Color, Tag Roblnson 9% 19% 9% 19% 18% 19 18% 19% 19% 22% Color Hold Tag Roblnso 17% 9% 19 18% 18 19% 19 21 Pour, F..- 15 15 15 25 20 20 25 30 25 01011 16 24 24 30 26 28 28 42 44 28 Sulfur, Wt. 11 O 21 0.20 0.27 0 14 0 16 0 20 0.19 0 10 0 14 0.16 Con. Carbon, Wt. pe ent 0 01 0.05 0.01 O 01 0 01 0 01 0.01 0 01 0 00 0.00 Aniline Point, F 224 222 220 221 221 221 221 221 221 222 Type of Catalyst Cobalt Molybdate, 10-20 Mesh Run Number Feed 479 480 481 382 494 495 "500 501 Feed Stocks. Panhandle Light Motor Raflinate Reactor Temperature, F 500 500 425 425 575 "575 575 625 Reactor Pressure, P st Q 700 700 700 700 750 750i. .750 750 Feed Rate, v./v./hr-- 3.1 3.1 3 1 3.1 3.1 3.1 4.7 4. 7 Total Gas Rate, s.c.f./hr 24 26 26 25 28 23 24 Hydrogen Sulfide Injected, Volume Percent of Total Gas... 5 11 12 6 68 70 Hydrogen Gas:

Volume Percent of Total Gas. 88 94' .50 40 32 30 S.c.f./Bb1. F 347 349 346 349 212 212 72 72 Product Inspections:

Gravity, API 30.7 30.9 30 9 30 7 30.8 31 0 81 0 31 0 91.0 Flash, F 465 460 470 470 465 455 450 455 455 Viscosity, SSU/ F" 324 316 318 323 322 311 311 312 306 Viscosity, SSU/210 F 54.6 54.2 54 3 54 7 54.6 54.0 54 1 54 1 53.7 Color, Tag Robinson... 5 13 12 10% 10 17% 17 '14 Color Hold Tag Robinson 4% 12 11 /4 9% 9% 17% 17% 14% 12% Pour, F 15 25 25 20 20 35; 5 35 Cloud, F .20 26 28 22 I 26- 45 4o 45 Sulfur, Wt. Percent 0.32 0.22 0.24 0. 33 0. 33 0.14 0.16 0118, 0.11 Con. Carbon, Wt. Percen 0.04 0.04 0.04 0,02 0.04 0.02 0.02. 0.02 0.03 Aniline Polnt, F 231 232 232. 232 231, 234 234 233 234 TABLE I-Contiiiued Cobalt Molybdate, 10-20 Mesh Type oi Catalyst Run Number Feed 483 y 484 485 486 496 497 Feed 521 522 525 526 Feed Stocks Panhandle 150-X Bright Stock Raflinate Reactor Temperature, 9F 500 50 550 600 575 575 450 500 500 450 Reactor Pressure, P.s.i.g 700 700 700 700 750 750 750 750 750 Feed Rate, v./v./l1r 3. l .0 3. 3.0 2. 9 3. l 3. 2 3. 2 3. 2 Total Gas Rate, Sci/Hr--- 24 26 29 29 36 14 14 20 20 Hydrogen Sulfide Injected, Volume Percent of Total Gm 11 22 22 61 76 0 0 28 Hydrogen Gas: 7

Volume Percent of Total Gas. 95 89 78 78 39 24 100 100 72 70 S.o.l./Bbl. Feed. 349 353 362 356 224 80 207 206 206 206 Product Inspections: 3 a

Gravity, API 27. 4 27. 3 27. 3 27. 5 27.7 27.4 27. 4 27. 5 27. 5 27.5 27. 5 27. 5 Flash, 0. 0. F 595 590 590 570 570 565 580 580 675 570 575 Viscosity, 85171100" 2, 410 2, 362 2, 422 2, 324 2, 258 2, 350 2, 333 2, 120 2, 094 2, 064 2, 090 2, 113 Viscosity, SSU/210 F 157. 2, 155. 7 155. 9 154. 4 151. 3 153. 7' 154. 7 145. 0 a 3. 8 142.2 143. 8 144. 7 Color, Tag Robinson 2% 4 4% 4% 5% +9+ +9+ 7 r 2% 3 4% 5% 4 Color Hold Tag Robins 2 3 3% 3% 4% +9+ 8, 6 7 2 -1%- 3% 4% 3% our, F 20 20 30 15 15 15 10 15 Cloud, F 22 18 18 52 26 28 31 31 29 Sulfur, Wt. Percent 0. 47 0. 45 0. 46 .0. 42 0. 29 0. 42 0. 43 0. 48 0. 47 0. 36 0. 45 0. 47 Con. Carbon, Wt. Percent. 0. 64 O. 0.72 0. 59 0.56 0. 68 0. 74 0. 64 0. 70' 0.73 0.63 0.65 Aniline Point, F 261 261 264 264 264 262 262 260 7 260 v 260 260 260 Selected products from the several runs illustrated in Table I were then subjected to a 36-hour L-4 Chevrolet engine test and these products were compared with similar products produced by clay contacting only and with lubricating oils hydrofined in the absence of hy sulfide in the enteringgas. In Table II the test results in Panhandle 150 neutral oils of Table I are presented.

- that samples SX-4803 and 4804 where the present invention wasalso practiced'had higher sulfur contents than the conventionally hydrofined oils of SX-4400. Sample SX-5479, on the other hand, had a'piston skirt drogen 30 varnish which was substantially the same as; that of the clay-contacted oil and had a lower average'bearing weight loss than any of the oils and yet the sulfur content of TABLE 11 36-hour, L-4 Chevrolet engine test results on Panhandle 150-neutral Sample Number SX-4174 SX-4400 SIC-4401 SX-4577 SX-4505 SX-4803 Hydrofinlng 'Iemp., F 575 575 575 475 500 Hydrofiner Run Number" 413 '413 41 3 465 474 Percent in Entering Gas; 0 0 0 11 5 Wt. Percent Sulfur (Before Additive)- 0.22 0.04 0.04 0.04 0. 20 0.14 Additive 0 0 0. 5% 0. 7% 0 0 1 L-1060 1 11-1060 36-Hr;, L-4Results: I

Piston Skirts SR1 (Southwest Research Institute) 8.8 6.1 6 1 9.1 6.8 6.8 Varnish, Total 46.3 40.1 40. 6 46.6 43.8 42. 3 Sludge, Total 47. 5 46. 0 48.0 8.0 46.5 45.0 Avg. BWL, gulls 0.728 2.854 1. 233 0. 015 1. 032 1. 627 Used Oil Data (36Hrs.): I

' Percent Viscosity Increase SSU/l00 F 23.3 30. 9 3.12 46. l

8ample Number SX-4804 SX-5150 SK-4962 SX-5479 SX-4805 SX-4806 Hydrofining Temp., F 550 550 575 500 475 550 Hydrofiner Run Number.-- 478 499 498 528 476 478 Percent H25 in Entering Gas" 22 68 68 66 10 22 Wt Percent Sulfur (Before Add 0. l0 0. 18 0.14 0 27 i 0. 0. 10

tive 0 0 0 0 0. 5 0. 5%

- 1 A 93O 1 A-93O 36-Hr., L-4 Results:

Piston Skirts SRI (Southwest Research Institute); 5. 4 7. 7 8. 3 8. 5 8. 2 0. 5 Varnish, Total. 39. 4 43. 7 45.8 46.0 45. 7 46.0 Sludge, TotaL- 44. 0 45. 0 47. 5 47. 5 47. 5 48. 0 Avg. BWL, gms 1.997 0.820 1. 632 0. 458 0.092 0.020 Used Oil Data (36-Hrs): Percent Viscosity Increase, SSU/100 F--- 53. 7 38.3 31. 2 18 7 15. 7 15. 7

l Zinc dialkyl dithiophospha'te. 4 Clay contacted.

Referring to Table II, 'it will be seen that sample No. 'SX-4962'has a piston skirt varnish of nearly equal quality to that of S X-4l74, Where the oil was finished by clay contacting. In this rating, the higher the value, the better the rating. Furthermore, SX-4962 is of better quality than the conventionally hydrofined oil as represented by SX-4400. It is to be noted that the sulfur content of the conventionally hydrofined oil of SX-4400. It is to be noted that the sulfur content of sample SX-4962 is greater than the sulfur content of the conventionally hydrofined oil of SX-4400. It to .be further noted ent invention than where a greater amount of additive was used in a conventionally hydrofined product. It may be seen from the data of Table II that at the preferred hydrofining temperature, a lesser amount may be sufficient to give the same quality as was obtained with 0.5% as in SX-4806. Hence, the additive requirements might be reduced anywhere from about 50% to about 85% by the practice of the present invention.

- obtained with a conventional hydrofined product. By

providing hydrogen sulfide in the inlet gas, it is possible to substantially improve the quality of the lubricating TABLE III 36 hour, L-4 Chvrolet engine test results on Panhandle LMO 1 Sample Number SEQ-3922 SX'-3923 821-3924 SX-4963 SX-4019 SDI- 4145 Hydrofining Temp., F 625 425 425 625 "425 HydrofinerRun Number (oliay 351 383 481 351 383 tacted Percent H18 in Entering Gas-.. 0 12 0 Wt. Percent Sulfur (before additive) 0.29 0.02 0. 0. 34 0.02 0 2 Additive 0 0 0 0 +0- 5% +0 1 11-1060 1 11-1060 36-Hr., L-4Results: Piston Skirts, SRI 9.3 9.0 9.2 9.1 9.5 a1 47.3 47.0 47.2 47.1 47.5

1 Zinc dialkyl dithiophosphate.

In order to show the improved results further, referring to Table III, it will be seen that oils of a quality substantially identical with clay-contacted produced oils are obtained. Comparing SX-3922 with SX-4963, which represents the present invention, the product of the present invention was substantially the same as the clay-contacted oil comparing the clay-contacted oil, as represented by SX-3922, and the oil produced in accordance with this v operation, SX-4963, with SX-3924, which is the conventionally produced oil, it will be seen that the practice of the present invention produces an oil which has a lower bearing weight loss and a higher sulfur content.

Referring to Fig. 2, the sulfur content of the Panhandle ISO-neutral is plotted against piston skirt varnish rating and average bearing weight loss. These data show that the bearing weight loss decreases as sulfur content of the hydrofined product increases and that the piston skirt 'varnish rating is dependent on the sulfur content and the hydrofining temperature. By way of explanation as stated supra, a low bearing Weight loss and a high piston skirt varnish rating are desirable. V

From these results, it is clear that the present invention gives substantially improved results over conventional hydrofining operations where hydrogen sulfide is not employed in the hydrogen-containing gas. I

The lubricating oil additives employed in the practice of the present invention may suitably include the wellknown lubricating oil antioxidants and corrosion inhibitors, such as described by Kalichevsky and Kobe in their work Petroleum Refining with Chemicals, Elsevier Publishing Co., New York, 1956, in Tables 159 and 166. Examples of such compounds are barium salt of alkyl phenol sulfide, cadmium, copper, or lead oleate or naphthenate, copper compounds, calcium salt of alkyl phenol sulfides or disulfides, metal alkyl xanthates, alkaline earth and alkaline metal salts of mahogany acids, aluminum diphenate, aluminum naphthenate, bivalent metal sulfonates, and the like. It is contemplated that these additives and those mentioned by Kalichevsky et al. supra may be employed inthe practice of the present invention.

These several antioxidants and corrosion inhibitors are given by way of illustration and not by Way of limitation.

'Inthe practice of the present invention, the sulfur content of the hydrofined product is greater than that which comprises hydrofining a lubricating oil fraetion'in the presence of a sulfur-resistant catalyst at a temperature within the rangefrorn about 400 toabout-575 F. under a pressure within the range from about 200 to about 1,000 pounds per square inch and at a space velocity within the range from about '1 to about;-1 0 v./v./hr. in the presence of sufficient free hydrogen-containing gas to provide from about 50 to about 5,000 standard cubic feet of hydrogen per barrel of said lubricating oil fraction, said gas also containing from about 5% to about 95% by volume of hydrogen sulfide, toforrn a product-containing an increased amount ofjsulfur and of improved lubricating quality over conventionally hydrofined oils.

2. A method in accordance with claim 1 in which the catalyst is cobalt molybdate. V

3. A method in accordance withfclai'rn 11 in which an inhibitor is added to-the product. 1

4. A method in accordance with'claim l in which the lubricating oil fraction is obtained'from Panhandle crude.

5. A method for producing an improved lubricatingoil which comprises hydrofining a lubricating oil fraction in V the presence of cobalt molybdate at af temperature within the range from about 475 to about,575 F. under a pressure within the range ffrom about 400'toabout'800 pounds per square inch and at a space velocity within the range from about 3 to about .5. v./v./hr. in the presence of sufiicient free hydrogen-containing .gas to provide from about 65 to about 500 standard cubic feet of hydrogen per barrel of'said lubricating oil fraction, said gas also containing trom about 20 .to about by volume of hydrogen sulfide to form'a product containing sulfur an increased amount of and ofimproved lubricating quality over conventionally hydrofined oils.

6. An improved lubricatingoil containing sulfur formed by hydrofining a lubricating oil fraction in the presence of a sulfur resistant catalyst at a temperature within the range from about 400 to'about 575 F. under a pressure within the range from about 200 to about 1,000pounds per square inch and at a space velocity within the range from about .1 to about 10 v./v./hr. in the presence of sufiicient free hydrogen-containing gas to provide from about 50 to about 500 standard cubicfeet of hydrogen per barrel of said lubricating oil fraction, said .gas also containing from about 5% to about 95% by volume of hydrogen sulfide. v

7. An improved lubricating oil in accordance with claim 6 in which the lubricating oil fraction is derived from Panhandle crude.

References Cited in the file of this patent UNITED STATES PATENTS Strang Sept. 11, 1951 Hoffman et a1. May 12, 1953

Claims (1)

1. A METHOD FOR PRODUCING AN IMPROVED LUBRICATING OIL WHICH COMPRISES HYDROFININH A LIBRICATING OIL FRACTION IN THE PRESENCE OF A SULFUR-RESISTANT CATALYST AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 400* TO ABOUT 575*F. UNDER A PRESSURE WITHIN THE RANGE FROM ABOUT 200 TO ABOUT 1,000 POUNDS PER SQUARE INCH AND AT SPARE VELOCITY WITHIN THE RANGE FROM ABLUT 1 TO ANOUT 10V./V./HR. IN THE PRESENCE OF SUFFICENT FREE HYDROGEN-CONTAINING GAS TO PROVIDED FROM ABOUT 50 TO ABOUT 5,000 STANDARD CUBIC FEET OF HYDROGEN PER BARREL OF SAID LIBRICATING OIL FRACTION, SAID GAS ALSO CONTAINING FROM ABOUT 5% TO ABOUT 95% BY VOLUME OF HYDROGEN SULFIDE, TO FORM A PRODUCT CONTAINING AN INCREASED AMOUNT OF SULFUR AND OF IMPROVED LUBRICATING QUALITY OVER CONVENTIONALLY HYDROFINED OILS.

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