US2058131A - Process of refining hydrocarbon oil - Google Patents

Description

success or an l Paul J. Carlisle, a l g mesne assients... w E, mom and ny, a aeration of a attain I N. Yep L- r du Pont de New No Drawing. Application May 12, 1931.,

Serial No. 53$.t2d 1 This invention relates-to the refining of hydrocarbons and more particularly to a process for refining hydrocarbon oils by adsorbent material and alkali metal.

Hydrocarbon oils, for instance lubricating oils, are frequently refined by treating with adsorbent materials, such as iullers earth. A large number 5 of methods of using fuller's earth and like rbents have been proposed, but the two most commen methods are: (a) the contact process, wherein the oil is agitated for a time with the adsorbent at a definite temperature and then illtered, and (b) the percolation process, wherein the oil is filtered through a thick bed of adsorbcut. These treatments are often preceded by treatmentwith sulfuric acid or other chemical.

adsorbents as heretofore used have been somewhat unsatisfactory as refining agents because of their relative inactivity toward the oil. This often makes it necessary to treat the oil many times before the desired quality is obtained. Large amounts of adsorbent are required per unit of treated oil recovered. Moreover large amounts of oil become entrained in the adsorbent necessitating expensive solvent extractions and subsequent separations for recovery. Even then the adsorbent itself is useless for further refining until revlvifled or reactivated by a. costly burning out process in which quantities of both oil and solvent are lost.

' It has been proposed to subject hydrocarbon oils in the vapor phase to successive treatments with metal and adsorbent. Vapor phase treatments are often unsuited to the treatment of the higher boiling hydrocarbons such as lubricating oils, because of the high temperatures required which cause cracking. Furthermore, this method of refining by metal treatment is usually uneconomical when-reactive metals like the alkali to metals are used because insoluble treatment'byproducts are formedwhich foul the metal before it is used up. It then becomes necessary in or- .der to avoid waste of metal, to recover the unreacted metal from the by-products, which is a relatlvely diflicult and costly operation. An object of this invention is to provide a relatively economical method of producing highly refined hydrocarbon oils. A further object is to enhance the utility or small amounts of alkali metal in treating hydrocarbons and simultaneously to increase the productivity and simplify the use of adsorbent refining agents.

[These objects may be accomplished according, to. my invention by acombination of treatments with alkali metal and anvadsorbent material, for

(fit. Edd-23) instance fullers earth, wherein the metal is substantially entirely consumed. Such combln instance by such treatment a practically neutral 15' oil may be rendered highly alkaline and of low resistance to oxidation. It therefore has been found necessary, as disclosed in the above mentioned copending application, to use an excess of alkali metal in order to obtain an oil of good 20 quality. I have now discovered the surprising fact that fullers earth, although a muchless reactive treating agent than alkali metal, may be used in place of the aforesaid excess. It'appears to be immaterial whether the oil is treated simul- 25 taneously or consecutively with alkali metal and fullers earth, provided that a substantial excess of the alkali metal is not used.

One method of carrying out my invention will now be described: alkali metal is added to the 30 oil in a suitable vessel, for instance, aniron tank, and the mixture is agitated at a temperature above the melting point of the metal and below cracking temperatures until substantially all the metal has reacted. This point may be deter- 35 mined by applying a chemical test for the metal to small samples of the oil, withdrawn at intervals of time. The oil is then filtered to remove insoluble treatment by-products, and the filtered I oil is subsequently treated with an adsorbent ma- 4;) terial by any feasible method. I prefer to, treat. the oil with a finely divided, for example -200 mesh, fuller's earth by either the contact or percolation method.

The proportional weight of alkali metal used 45 may be varied according to the quality of product desired, provided that the amount of metal added is such that it will be substantially entirely consumed during the treatment. The W 2'1 um amount of metal that react when contacted 50 with the oil under given conditions for a given "period of tlmecan be determined by preliminary experiments on small batches.

Another method of carrying out my invention comprises adding a mixture or alkali metal and as adsorbent material such as fuller's earth to the oil, heating and agitating until the metal is sub stantially entirely consumed and subsequently filtering ed the insoluble materials. By applying several treatments successively, various grades of oil may be obtained, the degree of refinement depending on the number of treatments and the amounts of alkali metal and adsorbent used in 1 each.

My invention may be used to obtain the same Example 1 Forty grams of sodium were added to 4 liters of a Pennsylvania oil and the mixture was strong 1v agitated at 225 C..until a test showed that no appreciable amount of the metal remained. The mixture was then filtered and the insoluble portion was extracted with solvent naphtha to re move adhering oil. The extract was distilled to separate solvent from the oil and the latter was added to the filtrate.

A 400 cc. portion of the filtered oil was percolated once through a bed of 650'grams of fullers earth which had been previously activated by heating to 400 C., comprising a 5 inch layer of 100-200 mesh earth covered witha l-inch layer of 30-60 mesh earth.

Another quantity of the same oil was percolated once through fullers earth under the same conditions and using the same ratio of oil to fuller's earth, but without the previous alkali metal treatment.

The results are given in the following table. The indicated characteristics of the-oils were determined by standard methods established by the American Society for Testing Materials.

Characteristics of the oils 0" permilfmd untroeizlated Neutralization No 0.00 0.00 0.00 Bligh Oxidation No. 0. 6.2 Steam Emulsion No- 0. 22.0 sec. Visc. 100 134.0 sec. Visc. at 210 F 43.0 sec Flash point, F. 390 Fire point, F 456 Color, N. P. A No. l

Yield (bbls. of oil obtained for ton oi iuller's earth used) 3.6 3.6

Example 2 A Pennsylvania oil was treated with sodium and filtered as described in Example 1 but not percolated and then was subjected to four successive treatments with fuller's earth, by the contact method. Each contact treatment comprised agitating the oil at C. with 250 grams oi. earth per liter of oil for 10 minutes, and filtering.

Another portion of this oil, not treated with sodium, was subjected to seven successive contact treatments with fuiler's earth. each treatment being identical with those given the sodium treated oil.

The results are given in the following table:

Pennsylvania oil was treated by strongly agitating for 30 minutes at 225 C. with a mixture of 10 grams of sodium and 250 grams of fuller's earth per liter of oil. The mixture was then filtered and the same treatment was applied to the filtrate. In both treating operations the sodium was substantially entirely consumed.

To other portions of the same oil were subjected to successive treatments with iuller's earth alone, using 250 grams of earth per liter of oil for each treatment and the same conditions as above. One of these portions was given two fullers earth treatments and the other, seven.

The following table indicates the degree of refining obtained in each case: i

While I prefer in my process to contact alkali metal with the oil at a temperature between the melting point of the metal and the cracking point of the oil, for instance at -250 C., other temperatures may be used, although, according to my experience, not so advantageously. Likewise, the alkali metal treatment may be carried out at either increased pressures or under vacuum, as

well as at atmospheric pressure.

The treatment with fullers earth or other adsorbent may be carried. out by any known method, and any number of successive treatments may be used, withoutdeparting from the, spirit and scope of my invention. Besides fulier's earth, other adsorbents, such as silica gel or alumina gel, may be used.

Although I have described my invention as a process for refining hydrocarbon oils by means of alkali metal, it is not limited 'thereto.. The process may be carried out by using any metallic refining agent which chemically reacts during the refining process so that it thereby may be substantially entirely consumed. Such metals in-' ciude not onlyalkali metals but also their alloys and other metals and alloys which react with the constituents and/or impurities of the oil to be refined. The metallic'refining agent may be used in either the fused state or as a finely divided solid metal.

Various modifications and adaptations of my invention may be used without departing from the spirit and scope thereof. For instance, the step comprising treating the oil with metal may be divided into a number of successive treatments. Also, the treatment with metal may be followed by any desired number of treatments with adsorbent or mixtures of metal and adsorbent, or by various combinations of successive treatments with adsorbent and adsorbent-alkali metal mixtures. A further possible modification is to follow a' treatment with a mixture of metal and adsorbent by treatment with adsorbent alone. A still further modification is to follow the metal treatment with the adsorbent treatment, omitting the intermediate step of removing insoluble treatment by-products.

Although I have described my invention by reference to a batch process, it may also be practiced as a continuous process. For instance the combination of a continuous liquid phase treatment with alkali metal, with a continuous process for treatment with adsorbent material comes within the scope of the present invention.

Other variations of my invention will be apparent to persons skilled in oil refining.

My process may be used to refine any liquid or solid hydrocarbons and the like, or solutions of gaseous hydrocarbons, no matter what their source or previous treatment. Thus it is equally applicable to oils which have been treated with sulfuric acid or other chemical and those which have had no pre-treatment of any kind. Likewise, it is equally applicable to the treatment of low-boiling hydrocarbons, such as gasoline and to the heavy hydrocarbons, such as lubricating oils. It also may be applied 'to the treatment of gaseous hydrocarbons dissolved in solvents which are not incompatible with the metallic treating agent used. a

My process is especially useful in treating certain hydrocarbon products, for instance those obtained from Pennsylvania crude oils, which often cannot be advantageously treated with suliuric acid.

One advantage oi my invention is that by its use oils of a given quality may be produced by the use of much less fullers earth than the processes now commonly practiced. Another advantage is that by my process oils of high quality, for instance colorless medicinal oils, may be produced with a comparatively mild fullers earth treatment, in contrast to the drastic acid and fullers' earth treatments heretofore necessary.

A further advantage of my invention is that it enables the alkali metal treatment of heavy liquid hydrocarbons to be carried out without using an excess of the metal, and thus avoids the troublesome and costly step of recovering unreacted metal. Heretofore, in order to obtain satisfactory refinement, it has been necessary to treat hydrocarbon oils with from 25% to around 200% excess of alkali metal. The recovery of the excess unreacted metal from treatment by-procl-' ucts is difficult and costly and considerable metal is often lost in attempting such recovery. My

invention eliminates the troublesome recovery step and avoids any waste of metal.

To obtain the various degrees of refinement that may be desired, the amount of. metal used, factors such as; temperature, time and degree of agitation, andthe extent of treatment with adsorbent may be varied according to the quality of oil desired. Obviously, the extent of treatment and modification of'my method necessary to produce oil 0! a certain grade will depend largei? on a viscosity of more than 50 seconds, Saybolt Universal at 100 F. The term hydrocarbons is understood to mean substances composed mainly of carbon-hydrogen compounds, but which may contain appreciable amounts of other substances as impurities. For the sake of brevity, the term "reactive metal in the claims, is used to designate any metal or alloy capable of chemically reacting with the constituents and/or impurities of the hydrocarbon being treated.

I claim:-

I. A process for refinlng'hydrocarbon oils comprising contacting hydrocarbon oil in the liquid phase with a quantity of alkali metal less than that required to produce a neutral oil at a temperature between the melting point of the metal and the temperature at which material decomposition of the oil occurs, under such conditions that the alkali metal is substantially entirely consumed, filtering the insoluble reaction products from said oil and thereafter treating said oil with adsorbent material.

2. A process for refining hydrocarbon oils comprising contacting hydrocarbon oil in the liquid phase with a quantity of sodium less than that required to produce a neutral oil at l00-250 C., under such conditions that the sodium is substantially entirely consumed, filtering the insoluble reaction products from said oil and thereafter treating said oil with fuller's earth.

3. A process for refining hydrocarbon oils comprising adding sodium to hydrocarbon oil in the liquid phase in an amount less than that which will produce a neutral oil, heating and agitating the mixture at 100-250 C. until the sodium is substantially entirely reacted, removing insoluble treatment by-products from said oil and thereafter treating said oil with fuller's earth.

4. A process according to claim 3, in which the step comprising heating and agitating with sodium and removing insoluble by-products'is divided into a plurality of successive operations.

5. A process for refining a liquid hydrocarbon comprising agitating liquid hydrocarbon with molten sodium, the proportion of sodium to hydrocarbon being less than that required to produce a neutral product until the sodium is substantially completely consumed, and subsequently treating the resulting alkaline product with fullers earth.

6. A process for refining a hydrocarbon oil comprising agitating said oil in the liquid phase with an amount of. sodium less than that required to produce a neutral oil and at a temperature of 109 to 250 C. until said sodium is substantially completely consumed, filtering the solid reaction products from said 011 and agitating the resulting alkaline refined oil with sufficient fullers earth produce a neutral product.

'I. A process for refining hydrocarbon oil which comprises agitating said oil in the liquid phase at a temperature of 100 to 250 C. with a quantity of sodium less than that which would produce a neutral oil substantially completely reacted alone with said oil, together with such amount of fullers earth that a neutral product is obtained on complete reaction of thesodlum and continuing the aforesaid operation until the sodium is substantially entirely consumed.

8. A process for refining hydrocarbon oil which comprises agitating said oil in the liquid phase with a quantity of. molten alkali metal less than that required to produce a completely refined, neutral oil until said metal is substantially completely consumed whereby an alkaline oil containing soluble reaction by-products is obtained, filtering said alkaline oil to remove any insoluble materials present and finally treating the filtered oil in the liquid phase with sufilcient adsorbent material to precipitate said reaction by-products and produce a neutral oil.

9. A process for refining hydrocarbon oil which comprises agitating said oil in the liquid phase with a quantity of molten sodium less than that required to produce a completely refined, neutral oil until said sodium is substantially completely consumed whereby an alkaline oil containing soluble reaction by-products is obtained, filtering said alkaline oil-to remove any insoluble materials present and finally treating the filtered oil in the liquid phase with sufiiicient adsorbent material to precipitate said reaction by-products and produce a neutral oil.

i 10. Aprocess for refining hydrocarbon oil which comprises agitating said oil in the liquid phase with a quantity of molten sodium less than that required to produce a completely refined, neutral oil at a temperature of 100 to 250 C. until said sodium is substantially completely consumed, whereby an alkaline oil containing soluble reacremoving insoluble material from said oil, the

quantity of said adsorbent material being such that a neutral oil is obtained and the quantity of said alkali metal being such that it completely reacted alone with such oil, an alkaline oil would .be formed.

12. A process for refining hydrocarbon oil comprising agitating said oil in the liquid phase simultaneously with molten sodium and an adsorbent material until said sodium is substantially comp'letely consumed and thereafter removing insoluble material from said oil, the quantity of said adsorbent material being such that a neutral oil is obtained and the quantity of said sodium being such that if completely reacted alone with such oil an alkaline oil would be formed.

PAUL J. CARLISLE.

I CERTIFICATE OF CORRECTION.

E atent No. 2,058,131.

I PAUL J. YCARLISLE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3,- second column, line 66, claim 6, strike out the word "refined"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of December, A. D. 1936.

Henry Van Arsdale e Acting Commissioner of Patents.

October 20, 1936.