US1675462A - Process of producing high-viscous lubricating oil and high-grade asphalt from petroleum - Google Patents

Description

TING OIL AND HIGH GRADE ASPHALT FBO! PETROLEUI /A/V'A/ff? ,qr/J/PA/Fns' 2 Sheets-Sheet l A. El FEW, JR PROCESS or PRODUGING HIGH viscous LUBRIcA Filed Dec. 22, 1926 July 3, 192s.

)Wm/615;- Y W July 3, 1928. 1,675,462

'rma on. AND HIGH GRADE ASPHALT FROM 'PETROLEUM Filed D60. 22, 1926 A. E. PEW. JR HIGH VISCOUS LUBRICA 2 Sheets-Sheet Y2 PROCESS OF PRODUCING J m F l l www/171? r//qr' 5 fuf,

Patented July 3, 1928.

UNITED STATESl PATENT l OFFICE.

ARTHUR E. PEW, JB., OF BBYN IAWB, PENNSYLVANIA, ASSIGNOB '.lOv SUN OIL COI- PANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

PROCESS OF PBODUCING HIGH-'VISCOUS LUBRICATING OIL AND HIGH-GRADE ASPHALT FROM PETROLEUM.

Application led December 22, 1926. Serial No. 158,288.

In certain prior applications filed by me jointly' with Henry Thomas, Serial No. 699,615, led March 17, 1924, Serial No. 13,040, tiled March 5, 1925, and Serial No. 112,443, filed May 29, 1926, and in certain a plications filedv by me, for example, Serial i o. 112,485, iled May 29, 1926, and Serial No. 159,754, tiled January 8, 1927, apparatus and processes are disclosed wherein, if a sutliciently high vacuum is maintained on the heavy residual oil from which lighter lubricating fractions have been distilled, distillation can be continued until there is nothing left except asphalt, the distillation of the heaviest fractions proceedin under such conditions that there are pro uced lubricating oils of viscosities never theretofore pro,

duced from a given crude, and so that nothing is left (if the crude oil have an asphalt base) except asphalt, the latter being also of-a high quality never heretofore produced with a given crude, Another characteristic feature of the process is that none of the oil is virtual] wasted by conversion, asis usualv inl the al distillation, into fuel oil; lthe final distillate being, in fact, the most valuable of the distillates because of its extraordinary viscosity. There are other valuable features of the process, such as lack of necessity of subsequent purification processes, and extreme economy in expense of operation, that needv not be herein discussed.

The principal conditions which are either essential or of material importance in securing the successful practice of the process may be roughlysummarized as follows:

(1) The preparation, from the crude oil,

of a residual oil suitable for distillation into lubricating oils, by distilli'n from the crude oil the lighter fractions, suc i as gasoline and gas oil, under conditions which 'avoid cracklng or access ofair to the oil.

(2) The maintenance of every particle of the oil, especially during the distillation of the heavier lubricating fractions, under a4 -welded to, the plate c.

sible e uivalent, such as diphenyl oxide, benzo p enone, sulfur or some possible metal alloy, as a heating medium whose latent heat 1s, by condensation, transferred to the oil.

(4) '1 he application of heat directly to the 11 uid oil and the avoidance of direct application of heat to the oil vapors.

(5') The avoidance of prolonged contact between the oil vapors and the liquid oil.

(6) The subsequent deodorization of the oil vapor condensate.

The present process comprises an improve ment on the processes of the specified applications and particularly on the process of application Serial No. 159,754, filed January 8, 1927 whereby the final distillation is conducted under conditions that facilitate and insure the production of a lubricating oil ofextremely high viscosity and an asphalt containing little insoluble material and hav- 111g a soft penetration and high melting point.

The process is not dependent for its execution von any particular apparatus, but the one shown in the drawings isl intended and adapted to effectively carry out the process.

Flg, 1 is a longitudinal section view of the vaporizing unit. l

Fig. 2 is a section on the line"22 of ig. 3 is a cross-section through the vaporizing unit.

Fig. 4 is an enlarged detail view of a part of the vaporizin'g unit.

Fig. 5 is a kdiagram showing the Vaporizing unit and pipe connections therewith. The vaporizer is divided by a transverse plate c into a lower chamber a, which, for convenience, I shall call a. gas oil chamber, and an upper chamber b, which, for convenience, I shall call a vaporizing chamber.

Cast in the plate c, and extending longitudinally thereof, are a number of pipes or tubes d. These tubes project beyond opposite ends of the va orizer, where they are manifolded into hea ers e and f.

Vertical risers g extend through,and are Slots h are cut in risers near their upper ends. Mounted on the risers g are deflectors i, which are preferabl of hemispherical form and provided wit i serrated edges.

In one end of the vaporizing chamber is an oil distributing pocket formed by a partition j. This pocket is fed from an oil inlet pipe k. At the other end of the vaporizing chamber is a tar outlet pipe m. Arranged along the top of the vaporizing chamber is a series of vapor outlets n.' A gas oil inlet pipe o communicates with gas oil chamber a,.whic h also has an outlet pipe y) for drainage.

There is continuously fed through pipe c a heavy ltarr oil, actually a mixture of heavy oil an asphalt, the saine being the vresidue of an oil from which lubricatingv distillates of viscosities varying from low to high have been previously distilled. This prior distillation should be conducted under the ,conditions hereinbefore specified in order. to insure the production of the supervizcous oil and high grade asphalt which it is the object of the present invention to secure. The heavy oil flows over the edge of partition j and thence flows down over the upper surface of plate c.

At the same time, mercury vapor is flowing into header e and thence into tubes (l, wherein the mercury condenses and thereby imparts heat to the oil that is traversing the plate. The mercury as a condensate fiows into header f and thence to a mercury boiler (not shown) wherein it 'is re-vaporized and again utilized as a heating medium.

Also, at the same time, a relatively light hydrocarbon (gas oil vapor is quite suitable) is flowing into chamber a and thence through risers g into the space under the deflectors z'. As shown in the drawings, these deflectors are partially immersed in the oil stream (which is preferably of minimum practicable thickness). The gas oil va ors are thus forced to bubble through the owing stream of tar, thereby imparting to the latter tremendous agitation and turbulence. Thereby the surface tension of the tar is greatly reduced, and by such reduction in surface tension, as well as by entrainment, the vaporization of the less heavy portion of thetarry oil is greatly facilitated, the mixture of gas oil vapors and heavy lubricating oil vapors escapingthrough the outlets n. It Should be understood that the drawings do not pur rt to illustrate the turbulent condition o the oil within the pool of oil shown. j

To vaporize the extremely heavy fractions whose vaporization is effected in my process requires, ordinarily, a temperature so high that the oil, in the course of its vaporization, is so badly cracked and decomposed that it is fit'only for fueloil, while the resultant asphalt is of inferior grade `and commands a relativelylow price. I aim to maintain the flowing Stream of oil or tar under a very high vacuum, the higher the better; it being known that the boiling point of a hydrocarbon falls at a rate which is constantly accelerating as any absolute vacuum is approached; It is entirely practicable to maintain the tari' vacuum ivquivaleut to a fraction of an inch mercury absolute pressure. However, the mere establishment of a high vacuum above the surface of the oil body` would be ineffective in those usual processes wherein the oil is distilled in batch from a column of oil, because of the hydrostatic pressure that would produce, toward the bottom of the column, an absolute pressure that would raise the boiling point so high that only destructive distillation woilld be possible. In my process, the column of oilof very slight depth, and hydrostatic pressure is nominal. Even, however, with the entire body of the oil subjected to the necessary high vacuum, the use of ordinar furnace gases, superheated steam, or the like, would be impracticable because of their low heat transfer and the consequent necessity of 1a big teniperatui'e ditfereiice between the heating medium and the oil. This would necessarily produce local overheating with resultant destructive distillation, coke formation, etc. By the use of mercury vapor, because of its high rate of heat transfer on condensation, the temperature difference may be reduced to a comparatively'small 'fraction of.that required in the use of other heating media. Myprocess also avoids the direct application of heat to the vapors, the heat being directly applied only to the liquid, thereby still further reducing liability to cracking. Further, an ample space is provided for expansion of the vapors and their outlet from the vaporizer is facilitated by the preferable provision of a plurality of vapor outlets, so that the vapors, once they form, are subjected only momentarily to the influence of even the reduced high temperature which exists in the vapor space above the liquid body; therebyalso avoiding the pressure drop that would existbetween the point of vaporization and the point of vapor escape rif the vapors vwere forced to travel for a substantial distance through a confined space and parallel with the direction of flow of the liquid.

All these factors make it posible to' practice tlie process, with al substantial degree of however, a very heavy oil, or tar, or mixture of heavy oil and asphalt, is being distilled,`

the surface tension of tlie'asphalt is so great that a fairly satisfactory distillation can be oil under a success, without other provisions. Where,

vapor, this surface tension is released and thereby, as well as by entrainment, the heavy lubricating oil is vapor-.ized both rapidly and completely, leaving a` residue` ol asphalt that is characterized by soft penetrability and a high melting point and that, by 'reason of its reduction without (lecompositlon, contains little insoluble lnaterial. l"hcse-char acteristics are those of' a high grade asphalt heretofore unknown as a product of the petroleum industry.

It is preferred that the gas oil itself, before introduction to the vaporizer, shall be distilled under vacuum, although, owing to its relatively low boiling point, an extremely high vacuum is unnecessary. Indeed, it is preferred that the crude oil from which the gas oil used in my process is obtained shall be subjected to distillation under such conditions as will avoid cracking and oxidation, and that the residual oil'resulting from the topping of the crude oil shall also besubjectcd to distillation into lubricating oils under non-cracking and non-oxidizing conditions; because. the purest heavy viscous oil and the highest grade asphalt can only be produced by my process in case the heavy feed stock and the relatively light hydrocarbon that is passed through the feed stock be substantially free of those decomposition and oxidation products that it is sought to exclude from the high .viscous distillate and asphaltic residue that my process produces.

It should also be understood, that the gas oil should be under an absolute pressure somewhat higher than that within the vaporizer to enablel it to freely and actively penetrate the flowing stream of oil and asphalt. It should also be understood that any relatively light hydrocarbon, such as kerosene or a light lubricating oil, may be used in place of thel gas oil.

The mixture of gas oil vapor and heavy lubricating vapor escaping through vapor outlets n goes to a fractionating tower t. Reflux condenser u, with water inlet r and water outlet 8, condenses the heavier oils, throwing them down into receiving tank fv, which is maintained under vacuuln and from which the oil is pumped. The gas oil vapors leaving tower t go to condenser w and thence to tank w, which is also maintained under vacuum and from which the oil is pumped.

The process herein described is also applicable to the distillation from residual oil of lubricating oil fractions lighter than the heaviest lubricating constituents.

A striking feature of the present process is that both the distillate and residue produced by my process are products that are believed to have been heretofore unknown in the art of petroleum refining. The special qualities of the asphalt have been mentioned. The qualities of the distillate will, of course,

vary with the character of the crude oil and the percentage of heavy oil that is associated with the asphalt in thc mixture to which the process is applied. A typical distillate from a typical naphthenic base crude oil will have a viscosity of about 271 seconds Saybolt universal (210 F.), a flash point of about 530, a lire point of about 630 F., and a gravity of about 12.5.

Having new fully described my invention, what I claim and desire to protect by Letters Patent is:

1. The process of separating the heaviest and less heavy constituents of heavy residual mineral oil which comprises subjecting a flowing shallow stream of such oil to a low absolute pressure and to a temperature above the vaporizing points of the less heavy con- Stituents at such low pressure, and simultaneously therewith passing through the flowing stream a relativel light hydrocarbon substantially lighter tran said less heavy constituents of the heavy residual oil, thereby agitating the flowing liquid and, by relieving surface tension and by entrainment, effecting maximum vaporization of said less heavy constituents, and separating the latter and said light hydrocarbon.

2. The process of separatiugthe constituents of heavy residual mineral oil which comprises subjecting' a flowing shallow stream of such oil to a lowl absolute pressure and to a temperature above the vaporizing points of the less heavy constituents at such low pressure, and simultaneously therewith forcing through the flowing stream vapors of a relatively light hydrocarbon, also under a low absolute pressure but under a higher absolute pressure than that to which the flowing stream is subjected, in such manner as to effect substantial turbulence and agitation of the flowing stream.

3. The process of separating the 'constitu` ents of heavy residual mineral oil which comprises subjecting a flowing shallow stream of such oil to a low'absolute pressure, forcing through the flowing stream a relativel light hydrocarbon vapor to produce agitation and turbulence therein, and flowing into heat exchange relation with the oil stream mercury vapor at such temperature and pressure as to effect, by heat eX- change and condensation of mercury vapor, the va orizationof said less heavy constituents o the agitated and turbulent flowing stream, removing the vapors and separating and condensing said vaporized constituents.

4. The process of separating the constituents of heavy residual mineral oil which comprises subjecting a flowing shallow stream of such oil in a heated condition to an absolute pressure substantially less than one inch mercury, forcing through the flowing stream a relatively light hydrocarbon, also under a low absolute pressure, at a number of points and thereby agitating the with the vapor space above the owing stream, flowing into heat exchange relation stream.

-with the oil stream mercury vapor at such In testimony of which invention, I have pressure and temperature as to effect, by hereunto Set my hand, at Philadelphia, 5 heat exchange and condensation of mercury Pennsylvania, on this 15th day of December,

vapor, lthe vaporization of said less heavy 1926.

constituents, and maintainin the mercury vapor out of direct heat exc ange relation ARTHUR E. PEW, JR.

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