US1592058A - Process for refining mineral lubricating oils - Google Patents

Description

Patent ed July 13,192

" UNITED STATES 1,592,05&

PATENT orr cs JAMEs W. WEIB, or FILLMORE, cALiroImIA;

, rnociiss roa Bar um; MINERAL ULUBRIQATING oILs.

No Drawing. i

This invention relates to the manufacture of lubricating oils, and refers particularly to improvements in the treatment of lubrieating oil stocks frommineral or petroleum oils with sulfuric acid.

In the treatment and refining of lubricating' oil stockswith mineral petroleum oils,

the stock is commonly treated with. sulfuric acid. The sulfuric acid is added to the lubricating oil stock and the admixture agitated for a period of time until the purification reaction substantially ceases. Asa result of such reaction, a quantity of sludge or partiall spent acid is formed. The strength 0 sulfuric acid in the produced sludge, while at too low a potential strength for further refining of the lubricating oil stock commingled therewith, still possesses considerable potential strength in reference to its ability to treat untreated lubricating stock, or certain treated or untreated stocks of d-ijferent grade.-

Inan ordinary process of refining,-however, this residual sulfuric acid strength'of the sludge is not utilized. Moreover, in the practical application of acid in the treatment of lubricating oil' stocks, it is difficult to apply the acid to the stock so as to secure a substantially and economical efliciency in the reaction between the lubricating oil stock and acid without at the same time causing a violent reaction to. take place.

- The effect of-a too vigorous reaction bestock would possess an olive green bloom -or- =tween sulfuric acid and certain oil stocks imparts to the stock a bluish fluorescence or bloom, whereas otherwise the lubricating oil fluorescence by reflected light. Lubricating oil witha bluish fluorescence or bloom is generally considred' of low grade in the market.

.Itis an object of the present invention -.to provide a method of treating lubricating .7 that thisformation or imparting of a bluish oil stocks'vby which the sulfuric acid em-- ployed is more efficiently utilized and by whicha modified action of surfuric acid upon lubricating oil stocks is obtained, so

' fluorescence or bloomv to the finished stock is-avoided and a superior lubricating oil. lower rate of acid stock thus provided at a consumption. V The vprocess is articularly adapted 't0 the.treatment of ubricating oils wherein tional lu fining Application filed May. 14 1925, Serial No. 30,855.

it is desired to produce a lubricating 011 of intermediate viscosity or color from a stock of, low viscosity and light color and a stock of relatively high viscosity and dark color.'

It has hitherto been particularly difficult to treat, for example, heavy steam refined stock to a relatively light color as compared to the original stocks. Attempts to refine,

treat and filter to such a. comparatively light.

produce a stock of the undesired or bluish fluorescence. The method effects a modified sulfuric acid treatment secured by mixing such heavy stocks with an admixture of lighter, less viscous stocks and sulfuric. acid sludgeresulting from the treatment of such light stock with sulfuric acid. The mass is then agitated together so that the acid sludge willetfect a purification of the heavy v1s-.

cous stock under conditions which are found to substantially retard the imparting ofa bluish fluorescence or bloom to the resultant product. This is due. to the presence of the less viscous stock and the fact that the potential sulfuric acid strength of the sludge is materially reduced.v

The invention is particularly useful inconnection. with the production of blended intermediate stock from the use of a light.

and heavy oil stock. The method of treatment or modified'sulfuricacid treatment, however, may be .utilizedwherever, follow ing a sulfuric acid treatment of. one lubri-.

eating oil stock and-prior to the removal of thesludge formed thereby, any other addiand the mass agitated together. for the recase, the resultant action upon the second stock'is obtained, through a treatment thereof by a hitherto waste material, the urifi-' ricatingloil stock is added thereto of said additional stock. -In any cation being accomplished withoute acting or illustration of a process embodying theinvention.

'Lubricating oil' stock of relatively low viscosity is commingled with approximately fifteen pounds of sulfuric acid per barrel of stock under treatment and maintained in intimate contact for approximately fortyfive minutes. The stock is then allowed to settle, after which the sludge resulting from this acid treatment is preferably withdrawn. Then approximately twenty pounds of su lfuric'acid per barrel of stock is added'and similarly commingled and maintained in intimate contact with the oil stock for ap proximately forty-five minutes. "Then while the oil and admixed acid are still being com-V mingled and maintained in intimate contact,

filtered cylinder stock or lubricating oil stock' of relatively high viscosity is added and commingled with the first stock and sludge therefrom while still remaining therein for aperiod of approximately forty-five minutes. For example, 20% by volume of the second stock may be added. In this way, the sludge produced from the second sulfuric acid treatment of the first or lighter oil stock is caused to purify the second or added heavier oil stock, the purification thus being effected by a comparatively valueless material, ahd the sulfuric acid employed being more efiiciently utilized. Mereover, the resulting action is found to be substantially less vigorous and proceeds without the im parting of a bluish fluorescence or bloom to the blended finished stock.

Subsequent to such treatment, the sludge is permitted to settle from the oil stock and is then withdrawn.

After such an acid treatment, the lubricating oil stock may be finished by any preferred method, such for example, as washing or athering by water and neutralization wit an alkali soda, but preferably is finished in the following manner:

There still remains suspended in the oil a certain percentage of finely divided sludger or pepper which will not settle out of the lubricating oil stock and should be removed 7 to obtain a lubricating oil of high purity. This pepper may beremoved by gathering the same with a comminuted solid adsorbent material, the same being agitated with the stock at a temperature below the decomposing temperature of the sludge present. The comminuted solid adsorbent material may be added at'the rate of one ton of the solid substance to thirty thousand allons of the oil stock. Comminuted granite, diatomaceous earth, gdecolorizing clays or fulthe sulfur dioxide.

'lers earth are examples of solid materials which may be employed. The comminuted substance, with the sludge gathered and ad hering thereto, is then separated from the oil stock.

The oil stock still contains a quantity of 7 acid reaction products or acid'sludge in colloidal suspension or otherwise remaining in pose and liberate carbon dioxide. The .de-

composing sludge will adhere to the comminuted substance commingled with the oil and can then be removed, 7

The temperature of the treatment is 180 F. or above and may be as high as any temperature below the vaporizing temperature of theoil stock, although relatively i lower temperatures, such as 300 F. are preferred. During the agitation of the oil and solids together, an inert gas may be blown through the same to assist in the removal of Subsequent to such treatment, the lubricating oil stock is separated from the remainder of the mass and then, if necessary, is brightened by blowing with air in the usual manner.

This method of removing acid reaction products from the oil by adsorption with a comminuted solid substance is accompanied by no chemical reaction, and therefore no injurious compounds are formed which re main inthe oil or require removal by further process.

While I have described in detail the preferred method of refinin lubricating oils, it is understood that various modifications may be made in the details of the method and process, without departing from the spirit of the invention, and the invention is therefore not limited to the specific details set forth for the purpose of illustration, but includes all such modifications and substi tutions .as come within the scope of the apstocks, which comprises treating relatively low viscosity lubricating oil stock with sul-' furic acid until the action of the acid upon said stock is substantially complete, then' without removing the produced sludge from said treatment introducing relatively high viscosity lubricating 'oil stock to the admixture and commingling the same therewith, whereby the added oil stock is reacted upon by the acid sludge .resulting from the sulfuric acid treatment of the original stock.

- sulfuric acid and then,

lubricating oil stockto stock from the resultant sludge.

3. The method of refining a lubricating oil stock; which comprises treating relatively low viscosity lubricating oil stock with without removing the produced 'sludge from such treatment, adding-asecond relatively high. viscosity the admixture and continuing-the treatment, settling and removing the major portion of the sludge, and

then gathering and removing a further quantity of the sludge remaining in the oil stock'by treatment with comminuted solid adsorbent material.

4. The method of refining a lubricating oil stock, which comprises'treatin a lubricatlng oil of relatively low viscosity with sulfuric acid, then without removin thesludge, adding a lubricating oil of relatively higher viscosity, settling and removi g the major portion of the sludge, and gathering and removing a further quantity of the remainierof the sludge by the treatment with com- 'mi'nuted solid adsorbent material. 5. The niethod of refining lubricating oil stock, which comprises treatinga lubricating oil of relatively low viscosity with sulfuric acid, then without removing the sludge adding a lubricating oil viscosity and continuing the treatment, sepaof relatively higherrating the major portion of the sludge there-- from, commingling the lubricating'oil stock with a comminuted solid adsorbentmaterial at a temperature suflicient-to decompose the sludge present, and separating the adsorbent material with the material adsorbed 'f-rom' the oil stock. v

6. The method of refining lubricating. 011

stocks, which comprises treating a lubricating oil of relatively low viscosity with su lfuric acid, then without removing the sludge produced, adding a lubricating oil of relatively higher viscosity and continuing the treatment, removing the major portion of the sludge therefrom, and gathering the suspended sludge from the lubricating oil stock by adding and commingling therewith a comminuted solid adsorbentmaterial at a temperature below the "decomposing tem-' perature of the sludge.

7. The method of refining lubricatingoil stocks, which com rises treating a lubrieat-' ing oil of relative v low viscoslty with stil furic acid, then without're'moving the sludge,

, adding a lubricating oil of relatively higher viscosity and continuing the-treatment, re-

moving the major portion of thesludge formed. gathering the suspended sludge adding and commingling therewith a solid adsorbent material at a temperature below the decomposing temperature of the sludge,. removing the adsorbent material and gathered .sludge, agitating. the oilstock withcomminuted solid adsorbent material at a temperature sufiicient'to decompose the remaining sludge and liberate sulfur dioxide, and then separating the oil stock from the mass.

Signedat Los A geles, 'Galif., this 4- day of May 1925.

JAMES W. 'WEIR.