US1809862A - Process of refining oils - Google Patents

Description

June 16, 1931.

A. R. MOORMAN ET AL PROCESS OF REFINING OILS Filed Jan. 4, 1929 Patented June 16, 1931 uNrraDv STATES PATEnT OFFICE A ARTHUR R. MOORMAN, OF WOOD RIVER, ILLINOIS, IRVING C. CARPENTER, AOIE NEW ROCHELLE, NEW YORK, ASSIGNORS TO CONTACT FILTRATION COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF DELAWARE .PROCESS OF REFINING OILS ApplicationV f led January 4, 1929. Serial No. 330,309.

This invention relates to the treatment of oils and particularly relates to a process of neutralizing and decolorizing oils with nely divided solid adsorbents.

process is applicable to the rening of vegetable and animal oils, it is particularly directed to the treatment of petroleum oils such as lubricating oils.

By the use of the term adsorbent as hereinafter applied, we refer to the use of any finely divided or comminuted solid material capable of exerting an adsorbing action upon the oil being treated and including such materials as natural decolorizing or adsorbing clays, acid treated or otherwise activated clays, various forms of carbon, silica and other material.

Most oilssuch as lubricating oil stocks,'are

acid treated during refining, and it has been discovered previously that such oils containing small quantities of acid and acid reaction products may be neutralized without the application of alkaline solutions by Contact with comminuted solid adsorbents such as the mineral montmorillonite and other decolorizing clays.

When it is desired to neutralize acid oil with a finely divided adsorbent, it is general practice to agitate the acid oil with a quantity of adsorbent sufficient to produce the desiredB neutralization. In view of the fact that most of these adsorbents exert decolorizing effects upon oil, it is customary to heat mixtures of oil and adsorbentso as to simul- 35 taneously neutralize and decolorize the oil, the heat being applied so as to produce temperature conditions which facilitate the decolorizing and neutralizing reactions.V This process, while attractive from an operating standpoint, entails the usey of large amounts of adsorbents per unit volume of oil treated and, for this reason, the following modification has been suggested as being an economic improvement over the hereinabove described single step treatment. Y

This second method of treating acid oils so as to produce a neutralized and decolorized .oil consists in agitating the acid oil with a decolorizin 21j-so as to gat er all suspended sludge and tar Although the` clay at a moderate temperature resulting from a previous treatment with acid and then removing the clay together with the` sludge and tar by filtration. The cleaned oil, freed of tar and suspended sludge, is then agitated with fresh clay at a moderate temperature, or at a slightly higher temperature, so as to complete the neutralization', and again filtered to remove the clay. v The neutralized oil is then contacted with a further quantity' agitated together at a moderate temperature,l

say 10U-450 F., so as to effect neutralization, such decolorization as takes placel at this stage being merely incidental. The proportion of decolorization which takes place in this step depends somewhat upon the character of the oil. After the neutralized oil is separated from this spent clay or other adsorbent,.it is then agitated with a relatively small quantity of fresh adsorbent, the mixture being heated to a suitable decolorizing temperature. The adsorbent is then removed from the treated oil in any suitable manner and such removed and partly spent adsorbent may then be utilized for neutralizing a further quantity of acid oil.

The neutralization and major decolorization are therefore accomplished successively, and a different batch of clay is used to complete the decolorizing than that used for neutralizing, it having been found that clay having expended its decolorizing power 1s still effective as a neutralizing agent. Partially spent clay or other adsorbent which has been spent only in decolorizing oil is used t0 neutralize the acid oil, any decolorizing power remaining in the partially spent adsorbent acting to partially decolorize the stock during the neutralizing step. After/ruf separation of the completely spent adsorbent from the neutralized stock, fresh clay or other adsorbent is added thereto and the decolorizin operation completed.

T is cycle may be repeated indefinitely,l

- colorized with a fresh batch of adsorbent and such adsorbent, having been partially spent in adsorbing the coloring matter from the oil, may be used for neutralizing a further quantity of oil. The finished neutralized and decolorized oil obtained by this method is generally of better color than that obtained y former methods, while the total amount of adsorbent used per unit volume of finished oil will be found to be from ten to thirty percent less. This great reduction in quantity of adsorbent required to neutralize and decolorize oils is apparently due to the-fact that a relatively small quantity of adsorbent will exert a more complete decolorizing elfect upon an oil if such oil is first neutralized by means of partly spent adsorbent from such decolorizing reaction.

An object of this invention is to provide a method of neutralizing and decolorizing oils in which the quantity of adsorbent required is materially reduced from that generally required. f

Another object is to utilize an adsorbentofor neutralizing acid oils, which adsorbent has previously expanded all or part of its decolorizing power on neutralized oil.

Another object is to provide a method of neutralizing and decolorizing acid oils in separate steps.

A still further object is to provide a method of using partially spent adsorbents for neutralizin acid oils.

Anotiier object is-to provide a method o neutralizing 'and decolorizing acid oil in separatesteps, the decolorizing step being the source of adsorbent for the neutralizing ste ther objects and advantages of our process will be apparent from the following description of a process of neutralizing and decolorizing petroleum oils, the application of this process to the treatment of petroleum oils being stated in detail merely for purposes of illustration. i

Reference will also be had to the appended drawing, in which the various steps and apparatus required are diagrammatically illustrated. It is to be understood, however, that the hereinafter described detail process may be materially modified without departing from the invention, and the invention is not limited to a process employing all of the steps or the precise apparatus shown in the attached drawing, the invention including all such modifications as come within the sco e of the appended claims. y

enerally, 1n carrying out our rocess, it is necessary to first obtain abatch o partially spent clay or other adsorbent. For example, it may be obtained by using a batch of clay to decolorize oil which has previously been neutralized by caustic or other agent. The cycle can be most conveniently started by neutralizing an acid oil with a small batch of clay, discardino' such clay and then completely decolorizmg the neutralized oil with a fresh batch of clay. In the decolorizing operation the clay loses a part of its eiectiveness but is still sufficiently active to neutralize acid stock. The artially spent clay is then preferably added) direct to a batch of acid oil which is neutralized and also partially decolorized if the clay retains any of its decolorizing properties, the clay being thoroughly mixedA with the oil and the mixture heated to a temperature of ap roximately 250 F. or higher and preferab y with the use of steam.

The mixture may then be cooled below the temperature of substantial oxidation if the temperature employed in the neutralizing step is such that substantial oxidation of the oil would take place on exposure to the atmosphere, after which the spent clay may be removed from the mixture by filtration or other means of separating solids from li uids and discarded, leaving the neutralize oil in condition for further treatment.

The neutralized oil may be next charged into a treater equipped with means for heating and agitating the contents, and fresh clay added in an amount suitable to accomplish the desired decolorization, as previousl determined. The clay is well mixed wit the oil and the mixture brought to the proper temperature for decolorization and maintained at such temperature until the decolorizing reaction is completed. While the mixture is being brought up to this temperature, any low boiling constituents which may be present in the 011 may be removed by distillation, whereupon the operation may be preferably accompanied by steaming.V

The clay used in this step, although-its major decolorizing properties are exhausted, still retains its neutralizing power, and after separation from the oil by filtering is retained for use in theneutralization of a fresh batch of acid oil. The hot oil-clay mixture may be sent direct to the ilter and the oil cooled after separation or the mixture may be iven a complete or partial cooling before. tra.- tion. In any event care should'be taken to avoid contact with the atmosphere until the temperature of the oil is reduced below that of rapid oxidation. In separating the decolorizing clay from the mixture it is not essential that the partially spent clay be substantially denuded of oil, as any oil entraned in the filter cake is carried overinto the fresh batch ofacid oil which is to be neutralized by means of the partially spent clay.

While the removal of low boiling constituents from the neutralized oil has been described as taking place after-the fresh clay has been`added to the neutralized oil, it may be desirable to remove such fractions prior to the addition of fresh clay. This is for the reason that, under some circumstances, the decolorizing operation may be more efficiently carried out on substantially reduced stock. In such cases the neutralized oil may be heated to distill off the low boiling constituents, after which the heated oil may be mixed with the fresh clay and brought to the proper decolorizing temperature. As before, the clay is only partially spent in the decolorizing step, and after being filtered from the oil is used as a neutralizing agent for a fresh batch of acid oil.

Any suitable forms of apparatus may be used in carrying out the process of theginvention, which may be performed as a complete cycle or as separate steps as desired, an example of cycle operation being shown in the accompanying drawing.

Referring to the drawing, which represents a flowdiagram, the acid oil may enter the system through a line 1 and be mixed with a partially spent adsorbent such as clay which has been partially spent in the decolorization of neutralized oil. Such partially spent'adsorbent may be mixed with the acid oil entering the systeml through line 1 in a suitable mixing device such as the mixing tank 2, the partially spent adsorbent being supplied from a source to be hereinafter dcscribed and indicated by line 3. The mixture of acid oil and partially spent adsorbent from the vessel 2 may then be pumped by the pump 4 and through line 5 into another mixing tank 6. Means may be provided for heating the mixture in tank 6, such means being illustrated on the drawing by the heater 7, a portion of the mixture of oil and spent-adsorbent being circulated from tank 6 by means of the pump 8 through line 9 into heater 7 and returned to tank 6 through the line 10. Suitable valves such as the valves 11, 12 and 13 may be employed to regulate the flow or circulation of the mixture through the heater 7.

The acid oil is neutralized by the partially separating means such as the filter 17, the oil being discharged from the filter by line 18, while the discharge of spent clay is indicated by line 19.

The neutralized oil discharged from the filter 17 by line 18 may then be pumped by pump means 20 and through line 21 into a suitable mixing means such as the tank 22, wherein the neutralized oil is intimately contacted with fresh adsorbent, preferably in finely divided form, supplied through a suitable feeding means such as the hopper 23. If desired, the mixing means 22 may take the form of a tank or treating vessel in which the mixture of oil and clay or other adsorbent may be heated so as to distill off the moisture and low boiling constituents which may be' present, for which a vapor outlet 24 may be provided. The neutralized oil, together with fresh adsorbent added thereto, is preferably raised to a sufficiently high temperature to enable the decolorization to take place with greatest efficiency. Such heating may be attainedby circulating the mixture of oil and fresh'adsorbent from the treating vessel 22 through a line provided with a valve 25 and by means of a pump 26 through a heater 27 which mayf'contain tubes 28.

Aline 29 provided with a valve 30 may lead from the heater 27 back to the treating .vessel 22, thereby permitting the pump 26 to circulate a certain quantity of the mixture of oil and adsorbent through the heater until the desired temperature isreached. The oil and adsorbent may then be pumped by the means 26 through the lines 28 and 29 into line 3l by closing the valve 30 in line 29 and opening valve 32 in line 31.

The system may also be operated continuously to tank 22 and the material continuously removed through line 31 by regulation of valve 32 or by an additional pump in line 31.

In this manner the heated mixture of oil and adsorbent may be sent to a cooler 33 and therefrom into a suitable separating means such as the filter 34 wherein the decolorized oil may be separated from the partially spent adsorbent. The oil may be discharged through line 35 and, if desired, sent through a secondary cooler 36 before it is sent to a suitable storage, or for further treatment through line 37. The partially spent adsorbent separated from the finished oil in the separating means or filter 34 may then be spent adsorbent in tanks 2 and 6 and, after mixed with acid oil by sending to the mixing such neutralization, the mixture of oil and spent adsorbent may then be passed through line 14 into a cooler 15 where the temperature of the oil may be reduced to below the temperature of rapid oxidation, if such temperatures were reached by passing the oil through the heater 7. Generally, it is not i necessary to cool. From the cooler 15 the mixture of oil and spent adsorbent may be pumped by a pump means 16 into a suitable tank 2 through a line or other suitable means 3.

By utilizing the process above described, a

superior decolorizing effect may be obtained with a much smaller quantity of adsorbent or decolorizing clay than is necessary under methods used heretofore. In some instances the amount of decolorizing clay required has been as low as seventy-five percent of that formerly used. The re-use of the clay in the manner described has resulted in eliiciencies of ten to thirty percent over present methods and materially reduces the cost of neutralizing and decolorizing acid treated oils.

We claim:

1. The process of refining acid treated oils Which comprises heating the acid oil with a comminuted solid adsorbent previously used for decolorizing neutralized oil, separating the adsorbent from the oil, adding fresh adsorbent to the oil, heating the mixture to above 212 F. to decolorize theoil, and nally separating the decolorized oil from the adsorbent.

2. The process of refining lubricating oils containing acid reaction products, comprising agitating partially spent adsorbent with an acid oil in the presence of heat to neutralize the oil7 separating the spent adsorbent from the oil, adding fresh adsorbent to the neutralized oil, heating the mixture to above 212 F. to effect a decolorizing reaction on the oil, separating the partially spent adsorbent fromthe decolorized oil, and then contacting said partially spent adsorbent with a fresh batch of acid oil to neutralize the same.

3. The process of refining acid treated lubricating oils comprising mixing an acid oil with adsorbent partially spent in decolorizing neutralized oil, heating the mixture to about 250 F. to neutralize said acid oil, cooling the mixture below the temperature of rapid oxidation of the oil, separating the neutralized oil from the spent adsorbent, mixing the neutralized oil with fresh adsorbent, heating the mixture to a temperature aboveabout 250 F. to decolorize the oil, cooling the mixture below the temperaturel of rapid oxidation of the oil, separating the decolorized oil from the partially spent adsorbent, and then contacting the partially spent adsorbent with a fresh batch of acid treated oil to neutralize the sanie.

Signed at Wood River, Ill., this 5th day of December 1928.

ARTHUR R. -MOORMAN. Signed at New York N. Y. this 8th day of A November 1928. f

IRVING C. CARPENTER.

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