US1581370A - Process of manufacturing lubricating oils - Google Patents

Description

PATENT OFFICE.

JAMES WEIR, OI FILLMORE, CALIFORNIA.

PROCESS OF MANUFACTURING LUBBICATTNG OILS.

No Drawing.

To all whom it may concern:

Beit known that I, JAMES W. WEIR, a citizen of the United States residing at Fillmore, Ventura Count California, have invented a new and usefu Process of M anufacturing Lubricating Oils, of which the following is a specification.

In my copendmg applications Serial No, 545,438, for method of manufacturing lubricating oils, filed March 21, 1922, issued December 8, 1925, patent No. 1,564,501, and Serial No. 30,356, for process of rfining mineral lubricating oils, filed May 14, 1925, there are described processes for refining lubricating oils in which the lubricating oil, after a sulfuric acid treatment and a removal of the major portion of the resultant sludge, is commingled with a comminuted solid adsorbent material to decompose the sludge remaining in the oil so that the sand sludge may be removed by the adsorbent material. By such process it is possible to neutralize the oil after. the acid treatment without the usual caustic soda treatment.-

The present invention relates to an improvement upon the methods of such copending a plications, and is directed to cer tain modi cations in the method of treating lubricating oil described therein, by which it has been found that certain different and new results in the manufacture of lubricating oils can be obtained.

It is found that certain lubricating oils contain compounds and impurities, particularlv organic acids, which must be removed if the best grade of lubricating oil is to be obtained. Organic acids, for example, are encountered in lubricating oils un er the following conditions: (1) They occur naturally in certain crude petroleums; (2) they may be produced by decomposition of crude petroleum or its products during distillation; and (3) they may be produced by treatment of lubricating oils with. mineral acids.

, It is an object of the present invention to provide for the most efficient removal of such organic acids and other impurities in a process in which the final neutralization of the refined lubricating stock is carried out by the neutralizing methods of such copending applications. By such process, I am enabled not only to provide a lubricating oil free from impurities such as organic acids, but am also enabled to provide from naphthenic base crude lubricating oils -which Application filed November 9, 1925. Serial No.- 68,009.

have been heavil acid treated and thus thoroughly refine a lubricating oil which is free from compounds imparting to the oil a blue fluorescence and thus are markedly improved lubricants over those now generally produced.

Various other objects and advantages of the present invention will be apparent from the following detailed description of an example of a process embodying the invention.

The lubricating oil stock is first treated with sulfuric acid in any preferred or customary manner. The lubricating oil stock may be a distillate of any crude, either paraffin or naphtheni base, or mixed base; The first treatment with acid is preferably conducted so as to remove the majority of the undesirable acids from the lubricating oil stock, .and this preliminary or first acid treatment may be carried out by the addition of the acid in several successive portions to the oil stock, if desired, the addition of the acid in several portions resulting in the more eificient employment of the acid. For example, upon the familiar California base crude, I have employed first ten pounds of sulfuric acid of approximately 66 Baum in strength per barrel of Oll stock to be treated, and agitated the oil and acid to ether by compressed air or other means or a period of one hour. The admixture was then allowed to settle for a period of time of approximately four. hours and the resultant acid sludge drawn off. Thereafter a second portion of ten pounds of acid per barrel of stock was added to the oil stockand the admixture again agitated for a period of a proximately one hour. Then in order to e ect an efficient removal of all the sludge from the oil there is preferably added 3% of water to the stock and the agitation continued for approximately five minutes so that the sludge from the acid treatment would be properly coked, so that the finely divided sludge could be removed scribed in my patent application filed May 14, 1925, Serial No. 30,356.

Subsequent to such reliminary acid treatment of lubricating .011 stock, the stock is neutralized by an alkaline neutralizing agent where a caustic soda solution is used, the caustic soda solution is supplied to the oil hot and relatively weak. For example, to the oil stock is added 8% by volume of caustic soda solution of 3 gravity with sufiicient boiling hot water to render the neutralizing solution hot. The admixture is agitated until the alkali neutralizes all the acid present in the oil. This results not only sequent to such acid treatment, a further in an efiicient neutralization of the oil from all sulfuric acid reaction products, but also results in a neutralization and removal of substantially all the organic acids therein present. During agitation of the neutralizing solution and oil, the admixture is maintained at a temperatureof approximately 160 F. Upon completion of the reaction, the admixture is given a hot spray wash and permitted to settle. The alkali solution is then withdrawn and the oil washed free from traces of the alkali solution. The neutralized oil is then freed from traces of water by blowing air through the same or in any other preferred manner.

So far, the process of refining the lubricating oil stock is generally similar to the general process of manufacturing lubricating oils by surfuric acid and caustic soda. As a result of such process, the oil is freed from the majority of its organic acids. However, the heavy acid treatment of the oil stock when followed by a neutralization with caustic soda or other chemical neutralizing agent, is found to effect a fixing in the Oil of certain constituents which impart to the 011 a blue fluorescence. The exact nature of such constituents is not definitelyknown, but it is generally recognized that the presence of a substantially blue fluorescence indicates an inferior quality of lubricating oil. In order to free the lubricating oil from such impurities, the treated oil is again subjected to a sulfuric acid treatment.

In this last sulfuric acid treatment; it is generally necessary to apply only a relatively small quantity of acid, such as five pounds of sulfuric acid per barrel of stock. The acid and oil are agitated together in the usual manner and then permitted to settle and the resultant sludge withdrawn. Subquantity of the remaining suspended finely divided sludge is removed by adding as a coagulant a finely comminuted solid absorbent material in proportions of one ton of such material to 30,000 gallons of stock under treatment, the same being intimately admixed together for a period of about one hour. This treatment results in the removal of the major portionvof the finely di-" vided sludge which is left suspended within for example, of one ton of such material to 5,000 gallons of stock under treatment. This admixture is then agitated together while the stock is heated to a temperature of over 250 F. and preferably to 300 F., in order to cause the colloidally retained sludge to decompose and permit the same to be removed by the comminuted solid material, as explained in the aforesaid copending applications. The oil is then filtered from the admixture and cooled. Subsequently, the oil is brightened by blowing with air in the usual manner.

As a result of this second acid treatment and neutralization with a comminuted solid, the blue fluorescence imparted to the oil from the first acid treatment followed by the caustic soda neutralization has been destroyed and an oil of the desired green fluorescence obtained, such oil being of extremely light and stable color and free of such objectionable compounds as may be removed by alkali or other neutralizing agents.

lVhile a preferred example of a process embodying the present invention has been herein described in considerable detail for the purpose of clearly illustrating the invention, it is to be understood thatthe invention is not limited to such details, but includes all such modifications and changes as come within the spirit of the following appended claim.

I claim:

A process of manufacturing lubricating oil stock, which comprises treating the oil stock with sulfuric acid, removing the sludge, neutralizing the stock with an alkaline substance, separating such substance from the oil stock, thereafter applying further sul'- furic acid to the oil stock, settling and removing the formed sludge, then agitating the oil stock with a comminuted solid adsorbent material at a temperature below that at which the sludge. decomposes to gather a further quantity of the solid suspended sludge, separating the adsorbent material with the matters adsorbed thereon from the oil stock, then adding a comminuted solid adsorbent material to the oil stock, heating the admixture to a temperature suiiicient to decompose the remaining sludge and liberate sulfur dioxide therefrom, and separating the adsorbent material with the matters adsorbed thereon from the oil stock.

Signed at Los Angeles, Calif, this 30 day of October, 1925 JAMES W.' WEIR.