US2045160A - Process of treating fresh unused petroleum oils to produce decolorized lubricating oil stocks - Google Patents

Description

June 23, 1936. A, R MQQRMA'N ET AL 2,045,160 PROCESS OF TREATING FRESH UNUSED PETROLEUM OILS TO PRODUCE DECOLORIZED LUBRICATING OIL STOCKS 7 Filed Novr 26, 1929 smnnas gwvenfm Patented June 23, 1936 UNITED, STATES PATENT OFFICE PROCESS OF TREATING FRESH UNUSED PETROLEUM OILS TO PRODUCE DECOL- ORIZED LUBRICATING OIL STOCKS Arthur R. Moorman, Woodriver, Ill., and Irving C. Carpenter, New Rochelle, N. Y., assignors to Contact Filtration Company, San Francisco, Calif., a corporation of Delaware Application November 26, 1929, Serial No. 409,863

4 Claims.

Hitherto lubricating oils manufactured from residuals have generally been decolorizedby per- 19 colating the oils through a decolorizing clay at low temperatures. When the hot contact method of treating oils to decolorize the same was applied to lubricating oil stocks derived as a residuum from reducing crude petroleum oil, it was found l3 that excessive quantities of clay were required to decolorize the oil.

Basically, the hot contact process of decolorizing oils diifers from the percolating operation in the following respects. In a percolation process the clay is maintained in a bed of comparatively coarse particles while the oil at from normal temperature to about 250 F. percolates slowly through the bed. In the hot contact process comminuted clay is used and agitated with oil at elevated temperatures over 250 F. and generally from 350 to 550 F.

We have discovered that the amount of clay required to decolorize certain residuums may bereduced from 25% to 50% by the following procedure.

The neutral oil is first passed through a heating chamber to vaporize a portion of the oil; the heated oil is then passed to a chamber in which the vaporized portion of the oil is separated from the unvaporized portion of the oil. which unvaporized portion is thus reducedto a suitable residuum for the manufacture of lubrieating oils, the residuum so derived while still hot is agitated with the comminuted decolorizing agent, cooled, and the agent separated from the oil. This procedure produces at a low cost a decolorized oil by the hot contact method where previously the cost of treatment has been excessively high.

The process has been found particularly eifective on Pennsylvanian residuum consisting of from 12% to 35% of the original crude whose asphaitic content is sufficiently low as to permit of complete decolorization with the use of clay only. Also the process is found effective on treated, clay neutralized topped crude. The latter covers the use of mid-continent stocks in which the crude is topped taking oif the gasoline and kerosene and the residuum from this operation is acid treated and the oil neutralized by treatment with clay, filtered from the clay, the oil thus prepared requiring further reduction and decolorization to produce a residuum of the generally accepted specifications. In any event, the oil processed is either inherently'neutral or is neutralized prior to its introduction into the process.

The method of treating the oil to decolorize the same and produce lubricating oils of accept-, able specifications in accordance with the present invention will best be understood from a description of a preferred form or example of. a process embodying the invention. For this purpose there is hereafter described a preferred form or example of a process embodying the invention. It should be understood, however, that the particular details of treatment will vary somewhat widely depending on the particular oil processed and the kind of lubricating oil and color to which the lubricating oil is to be decolorized.

The process is described with reference to the accompanying drawing, in which:

The figure represents a diagrammatic view on flow sheet of an apparatus suitable for conducting the process.

Referring to the drawing, the raw material is picked up by pump 2 which discharges through a'heater 3 where sufficient heat is imparted to the oil to permit of the vaporization and fractionation of sufficient of. the charge in fractionating tower 4, as to leave a residuum of the required physical specifications for lubricating oil. The fractionating tower 4 may be of any design suitablefor this operation and well known in the art for fractionation of vapors in oil discharged from a heater such as the heater 3. The lighter fractions leave the fractionating tower 4 to a suitable condensing device (not shown) through line 5, leaving as a residue in tower 4, an oil or residuum satisfactory with regard to physical tests but requiring decolorization to produce a finished product.

The pump 6 takes suction on the bottom of tower 4 and discharges the hot residuum into a mixing chamber or tank 8 into which cla from a source (not shown) is introduced at I. In order to supply the necessary agitation or turbulenceto insure intimate contact and at the same time, supply the heat lost by the oil heating the clay and vaporizing any water in the clay. pump 9 takes suction on mixing tank 8 and discharges through heater l back into mixing tank 8, such vapors as may be produced being drawn oil at ii.

The outlet to heater I0 is provided with a valve II by means of which the clay and oil mixture is removed from the system by opening valve I I and starting pump l2. The amount removed by this means is proportional to the quantity entering the mixing tank 8 through pump 6. Pump l2 discharges through a cooler l3 and filter ll, where the clay and oil are separated, the clay being discarded and the oil passing through a cooler l5 into storage I.

Various comminuted decolorizing agents well known in the art may be used and these may be applied either dry or in the wet state. Acid treated clay of the montmorillonite class are especially suited for the process.

To illustrate the specific temperatures existing throughout the system when operating on a typical example of a 42 Baum Pennsylvania crude, the following temperatures are given. Crude enters heater 3 at F'. Crude leaves heater 3 at 750 F. Vapors leave tower 8 at 550 F. Residuum leaves pump 6 at 500 F. Clay and oil mixture is maintained in tank 8 at 475 F. Clay enters tank 8 at 70 F. Oil-clay mixture leaves pump 8 at 475 F. Oil-clay mixture leaves heater ID at 500 F; Oil-clay mixture leaves cooler it! at 200 F. 011 leaves cooler l5 at F.

The amount of clay ,used per gallon of oil to produce an oil of 6N. P. A. color varies from 0.5 pound to 1.25 pounds; whereas, the same oils previously had required from 0.65 pound to 1.7

pounds of clay per gallon of oil. These figures represent a saving in the 30% to 40%.

In certain cases, in order to maintain complete continuous operation of the process and to adjust the reducing operations relative to the decolorizing operations it may be desirable to insert a surge tank between the tower 4 and mixing chamber 8 to compensate for slight fluctuations in capacities between these units. This may be done without seriously effecting the operation as a whole. The temperature of the oil entering the mixing tank 8 should be as near that of the oil leaving tower 4 as practical operations will permit. Any reduction in temperature results in an increase in the amount of clay required in tank 8. Thus if the stock is cooled to 200 15. before entering the chamber 8, there is a marked increase in the quantity of 'clay required to produce any given color as compared to the same oil where the cooling has not been allowed to go below 400 F. Even where the oil enters the mixing chamber 8 at temperatures as low at 200 F., a much more economical operation is effected than the general practice of the prior art where the oil is .ntroduced at atmospheric temperature into the mixing tank.

Preferably; agitation in mixing tank 8 takes place in absence of air and the introduction of wet clay facilitates the operation due to the evaporation of the water from the clay forming a blanket of steam which prevents oxidation of .the oil.

The oil may be "stored at temperatures as high as 500 F. for several hours after leaving the tower 4 and before entering mixing chamber 8 if desired without darkening in color, especially if the oil is blanketed with steam at all times to prevent oxidation. Long standing of the oil at high temperatures, however, is to be avoided with oil rich in unsaturated straight, chain and present process of from cyclic compounds which tend to polymerize under heat.

Pennsylvania oils almost without exception may be more economically decolorized without than with the use of acid. Other oils such as reduced mid-continent crude may be acid treated and then neutralized by hot clay treatment prior to its introduction into the distilling unit of this process.

- No particular explanation of the saving of clay eflected by the present process is set forth for the reason that cause of or reason for such saving is not entirely known.

While the particular process herein described is well adapted to carry out the objects of the present invention. various modifications may be made without departing from the principles of the invention, and all such modifications and changes come within the scope of the appended claims.

We claim:

1. A process of treating fresh unused petroleum oils to produce decolorized lubricating 011 stocks, which comprises passing an oil a member of the group including neutral parafiine base crudes and acid treated clay neutralized topped asphaltic base crudes through a heating chamber to vaporize a portion of the oil and reduce the residuum to lubricating oil stock, and promptly thereafter .which comprises passing an oil a member of the group including neutral parafilne base crudes and acid treated clay neutralized topped asphaltic base crudes through a heating chamber to vapor-. ize a portion of the oil and reduce the residuum to lubricating oil stock, and promptly thereafter while the oil is still not adding thereto a decolor- -izing clay, agitating the clay and oil while heating the mixture, and finally cooling and separatirg the oil fromthe clay.

3. A process of treating fresh unused petroleum oils to produce decolorized lubricating oil stocks, which comprises passing an oil a member of the group including neutral parafiine base crudes and acid treated clay neutralized topped asphaltic base crudes through a heating chamber to vaporize a portion of the oil and reduce the residuum to lubricating oil stock, and promptly thereafter while the oil is still hot adding thereto a wet decolorizing clay, agitating the clay and 011 while heating the mixture, and finally cooling and separating the oil from the clay.

ARTHUR R. MOORMAN. IRVING -C. CARPEIITER.

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