US1872446A - Process of producing low boiling point oils or motor fuel from hydrocarbon oils by the employment of metallic halides - Google Patents

Description

g- R. A. HALLORAN ET AL 1,872,446

PROCESS OF PRODUCING LOW BOILING POINT OILS OR MOTOR FUEL FROM HYDROCARBON OILS BY THE EMPLOYMENT OF METALLIC HALIDES Filed March 16. 1927 COPIIFHSER CONDENSER IlzvuLeann-rn I Jam 11A W. W

(lbtozwugo gwwntou Patented Aug. 16, 1932 UNITED STATES PATENT OFFICE RALPH A. HALLORAN, OF BERKELEY, MARVIN L. CHAPPELL, 01' LOS ANGELES, AND

JAMES HAROLD OSMER, OF EL SEGUNDO, CALIFORNIA, ASSIGNORS T STANDARD OIL COMPANY OF CALIFORNIA, OF SAN FRANCISCO, camonlvrmn CORPORATION OF DELAWARE PROCESS OF PRODUCING LOW BOILING POINT OILS OB MOTOR FUEL PROM HYDRO- CARBON OILS BY THE EMPLOYMENT O]? METALLIC HALIDES Application filed March 16, 1927. Serial No. 175,83IL

' This invention relates to the treatment of hydrocarbon oils with metallic halides for the purpose of producing low boiling point oils or motor fuel.

The process of the present invention is intended to provide a method by which a maximum amount of motor fuel of low sulfur content can be produced from hydrocarbon oil with a minimum consumption of metallic halide. In accordance with the process of the present invention, hydrocarbon oil such as crude petroleum oil free of water is first distilled to remove-therefrom the natural motor fuel ongljsoline content while at the same time, meta 'c halide is introduced into the vapors under regulated conditions so that the metallic halide in this stage of the process acts only or substantially only to remove sulfur from the natural gasoline content of the crude oil, and causes some polymerization of highly unsaturated constituents. Said metallic halide and condensed oil of too high boiling point for use as motor fuel is continuously passed from the first distllling operation to a reaction zone wherein the metalp lic halide and high boiling point oil are maintained at a reactmg temperature for the production of motor fuel or naphtha through a metallic halide cracldng reaction.

- ,By the process of the present invention,

the metallic halide comes into contact with the natural gasoline content of the hydrocarbon oil under conditions where it operates to purify the natural gasoline content of the oil without substantially impairing its power for converting other higher boiling fractions ofthe oil to motor fuel or naphtha. Moreover, the aluminum chloride reaction which forms motor fuel from the higher boiling constituents of the petroleum oil is conducted upon a selected stock or fraction of the crude oil and by meansof the same metallic halide employed in purifying the natural gasoline content. Moreover,- use is made in the metallic halide treatment of such selected fraction of the residual heat in said fraction left from the primary or first distilling operation. Thus, by the process of the present invention, not only is the metallic halide caused to produce gasoline from higher boiling point oils but said metallic halide is caused to remove from the natural gasoline content of the oil the sulfur components and highly unsaturated constituents with the result that the natural gasoline derived is freed of gum forming constituents. This purification of the natural gasoline of the crude is also effected without said metallic halide being expended in its strength through reaction to se arate all of the unsaturated constituents o the natural gasoline. Agreat portion of the unsaturated constituents of natural gasoline are not detrimental in. motor fueland this class of unsaturated constituents is not substantially reacted upon by the metallic halide under the conditions of the present process.

The process of the present invention may also be employed for the treatment of distillates derived from a pressure distilling or cracking operation, in which case the pressure naphtha may be separated from said stock with a refluxing of the heavier oils and with the simultaneous removal of sulfur comounds from the pressure naphtha without all of the strength of the metallic halide being expended in this treatment. Moreover, the metallic halide-will react to polymerize from the pressure naphtha only those highly unsaturated constituents which, ifleft in the naphtha, will polymerize and produce gums or resins.

The present invention, together with various objects and advantages thereof will best be understood from a description of a preferred form of process embodying the invention. For-this purpose, a preferred example of the process is hereinafter described. The process is described as it is carried out in the apparatus illustrated in the accompanying drawing.

The drawing represents a diagrammatic view ofthe apparatus in elevation and main ly in vertical section.

Referring to the drawing, 2 indicates a still or vaporizing chamber which is connected by a vapor line'3 with the dephlegmator or reflux tower 4. The tower 4 is connected by a vapor line 5 with a condenser 6 which discharges into a receiver 7 for receiving gasoline or motor fuel. Said receiver 7 is provided with a line 8 connected with a vacuum pump 9 by means of which vacuum may be maintained upon the still 2, tower 4 and condenser 6, if desired.

The still 2 is provided with suitable heating means, for example, being mounted on a furnace 10 having a burner 11, and the still is also preferably provided with a residuum withdrawal line 12. The oiltobe processed enters the apparatus from a source, not shown, through 11116 13, and passes through a heat exchanger 14 in the dephlegmator or reflux tower 1 and hence by line 15 into the vaporizing chamber or still 2. Preferably the oil to be treated enters the still 2 through the distributor or spray producing device 16.

At the top of the dephlegmator or tower 4, there is preferably provided a metallic halide charger 17 by which metallic halide in either solid or liquid form may be introduced into the system. 18 indicates a line connected with the dephlegmator 4, preferably at a point spaced above the bottom of the dephlegmator for withdrawing c'ondensate and metallic halide. The line 18 is provided with a pump 19 by which the admixture may be placed under increased pressure and forced into a dephlegmator 20. The dephlegmator 20 is connected by a vapor line 21 with a reaction chamber 22. The dephlegmator 20 is also provided with a vapor line 23 passing through a condenser 24 and hence to a receiver 25 for receiving naphtha produced by metallic halide reaction upon the hydrocarbon oil. The dephlegmator 20 is also connected by a condensate line 26 with the reaction chamber 22.

The reaction chamber 22 may be of any construction adapted for agitating or contacting metallic halide and hydrocarbon oil together at a reaction temperature and is indicated as preferably mounted over a furnace 27 having a burner 28 for supplying the heat for the reaction. The reaction chamber 22 is also indicated as provided with suitable agitating means 29 and with a charger 3") by which additional metallic halide may be added if desired and with a residual withdrawal line 31.

The preferred process, as carried out in the described apparatus, is as follows: Any substantially water-free hydrocarbon oil may be employed, whether of petroleum, shale, or coal origin, but preferably a hydrocarbon oil is employed which contains some natural or already formed motor fuel content along with heavier or higher boiling point oils. For example, the process is particularly de-' signed for the processing of crude petroleum oil but is also of value in treating distillates derived from hydrocarbonoils by a thermal cracking process. The process will be first described with particular reference to the treatment of crude petroleum oil or other oil in which the motor fuel content possesses only a comparatively small amount of unsaturated constituents. Said oil is passed through the heat exchanger 14 and hence into the still or vaporizing chamber 2 where in it is heated to a temperature suflicient to vaporize the motor fuel content together with some heavier or higher boiling point oils and the vapors passed through line 3 into the dephlegmator 4. The temperature of the oil in vaporizing chamber 2 is, for example, maintained at between 450 to 550 F., and the distillation may be facilitated by the maintenance of a reduced pressure or vacuum upon the distilling apparatus applied by vacuum pump 9. The vacuum maintained is normally between 2 inches and 9 inches of mercury absolute pressure. In order to facilitate the evolution of the vapors in still 2, the crude oil from line 15 is preferably caused to enter the body of oil in reaction chamber 2 in a plurality of jets. Said jets by agitating the oil within the still 2 facilitate the copious evolution of vapors therefrom. Such conditions of temperature and pressure vaporize from the hydrocarbon oil the gasoline or motor fuel content, together with the higher boiling point oils such, for example, as fall within the so-called kerosene cut range and some of the so-called gas oil fractions. Within the dephlegmator '4, the vapors are subjected to fractionization so that onl the gasoline or motor fuel fractions escape t rough vapor line 5 and are collected in the gasoline receiver 7. The heavier fractions are condensed at different points in the dephlegmator 4.

imultaneously with the passage of vapors through the dephlegmator 4, metallic halide is introduced into the top of the tower. The metallic halide to be employed is usually anhydrous aluminum chloride, although similar results may be obtained by other metallic halides such as ferric chloride. The metallic halide is introduced into the dephlegmator 4 for the purpose of reacting with the sulfur compounds of the gasoline content of the oil and for the purpose of polymerizing or removing those highly unsaturated oils which would otherwise form gums in the gasoline produced. At the same time, it is not desired to polymerize or remove all of the unsaturated constituents of the gasoline by the metallic halide. Accordingly the metallic halide in the reflux tower 4 is either not in troduced in sufficient quantities to react with all of the unsaturated constituents, or the metallic halide is contacted with the oils or vapors in dephlegmator 4 only in the upper or cooler portions of said tower, or the metallic halide may be both introduced in insufiicient quantities to polymerize all the unsaturated constituents of the gasoline and be contacted with the gasoline vapors in only the upper or cooler portions of the dephlegmator. In this stage of operation, themetallic halide operates mainly upon such compounds as diolefines and acetylenes without r substantial reaction upon the aromatic constituents.

Since it is not necessary to have a large amount of metallic halide in the dephlegmator 4, preferably only a relatively small amount of metallic halide is introduced therein such, for example, as from .05 of 1 per cent. to .2 or 1 per cent. by weight of metallic halide per gallon of vaporized oil, although it is understood that the greater quantities of metallic halide may be introduced, provided the reaction is suitably confined by withdrawing the metallic halide from the upper portions of the tower 4.

The operation of the process is preferably continuous and the metallic halide commingled with condensed oil in tower 4 is continuously withdrawn through line 18. The line 18 preferably communicates with dephlegmator 4 where the condensed oil in said dephlegmator is at a temperature below 450 F., and preferably at a point above the bottom of the dephlegmator 4 so that there is withdrawn with the metallic halide mainly only the kerosene fractions of the oil, the gas oil fractions being permitted to return to m the still from the lower end of the tower through line 32. Another method of operating is possible, however. This consists in removing all the metallic halide and reflux condensate through line 32.

The commingled condensed oils together with the metallic halide are placed under increased pressure by pump 19 and continuously passed through dephlegmator 20 and line 26 into the reaction chamber 22, although, if desired, they may be run directly from dephlegmator 4 to chamber 22.

Within the reaction chamber 22, the metallic halide and hydrocarbon oil is heated up to a temperature suflicient to cause the metallic halide to react upon the oil for the conversion of said oil to low boiling point oil or naphtha. In case the quantity of metallic halide added to the oil in dephlegmator 4 is insuflicient for this purpose, additional metallic halide may be introduced into reaction chamber 22 from charger 30. For example, sufiicient additional metallic halide is introduced in reaction chamber 22 to bring the metallic halide in the reaction chamber up to from between 4 to 10 per cent. of the oil in reaction chamber 22.

, In reaction chamber 22, the reactionmay be continued with the production of a liquid metallic halide sludge which is continuously withdrawn from line 31 or the metallic halide may be reduced to a coke and the alumina recovered -for conversion into aluminum chloride by well known processes. In eithercase, the produced naphtha is continuously vanorized and the vapors passed through the dephlegmator 20 and finally collected in receiver 25. Preferably a pressure somewhat above atmospheric is maintained upon the admixture during this reaction such, for example, as a pressure of about 15 pounds per square inch gage. The preferred temperature of the admixture within the reaction chamber 22 is between 500 F. and 650 F.

By the process thus described, the metallic halide is adapted to purify the gasoline content of the hydrocarbon oil to be treated without substantially impairing its powers to react upon the heavier boiling point oils for the conversion of the same to naphtha. Moreover, this is accomplished without the metallic halide reacting upon the aromatic -constituents of the oil which have boiling points within the gasoline range.

When the process of the present invention is employed for the treatment. of distillates derived by the thermal decomposition of hydrocarbon oils, due to the high percentage of unsaturated constituents having boiling points within the naphtha range, the vapors of such pressure distillates are contacted in dephlegmator 4 only with a comparatively small amount of metallic halide or at a comparatively low temperature. The admixed condensed oils and metallic halide from dephlegmator 4 are then preferably passed into reaction chamber 22 and the admixture maintained at a temperature below 550 F. to polymerize the remaining oil to form high grade lubricating oil. It is understood, however, that at times, the reaction in chamber 22 even with such pressure distillates may be carried on for the production of naphtha. It is further understood that the process may be operated for the production of lubricating stock when employing other than cracked distillate.

It is understood that the naphthas derived from the present invention may be processed in any suitable manner for the removal of any hydrogen chloride gas or other usual or customary refining operations.

While the process herein described is well adapted to carry out the objects of the present invention, it is understood that various modifications and changes and substitution of equivalents may be made without departing from the invention, and the invention includes all such modifications, changes, and substitution of equivalents as come within the scope of the appended claim.

We claim:

A process of treating hydrocarbon oil containing motor fuel fractions and heavier fractions with metallic halide which motor fuel fractions contain acetylenes, diolefines, and sulfur compounds, which comprises distilling said oil under a. reduced pressure less than atmospheric, fractionating the evolved vapors to separate the motor fuel fractions, contacting metallic halide with the vapors being fractionated to remove therefrom mainly acetylenes, diolefines and sulfur compounds before any decomposing action of the metallic halide upon the heavier fractions, Withdrawing Vcommingled metallic halide and condensed oils from said fractionating zone, and contacting the same at a temperature sufficient for the metallic halide to decompose a part of said condensed oils to form lower boiling point oils. Signed at Los Angeles this 28th day 0 February, 1927.

MARVIN L. CHAPPELL. Signed at San Francisco this 4th day of March, 1927.

RALPH A. HALLORAN. JAMES HAROLD OSMER.

Images