US1766983A - Process for the destructive distillation of petroleum oil - Google Patents

Description

June 24, 1930. A. D. DAVID 1,766,983

` rnocass FoR THE DEsTRuc'x-Ivf: DISTILLATION oF PETROLEUM on.

Filed Feb. 14, 1923 Pafesfed June 24, 1930 y UNITED STATI-:s AParri-:NT.o1-*lucia AUDREY' D. DAVID, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA Application filed February 14, 1923. Serial No. 619,037.

This invention relates to improvements in a process for distilling petroleum oil and refers more particularly to the pressure disl tillation of oils to produce relatively light' hydrocarbons having the characteristics of gasoline.

Among the objects of the invention are to provide a process in which the deposited free carbon particles separated out durlng the conversion of the oil are removed from I the conversion stage by a flotation medium and the carbon particles eliminated therefrom in a separate oxidizing stage; to provide a process whereby the oil may be treated over a considerable period of time due to the fact that the carbon accumula- Y chamber which is connected by a vapor line 4 to a dephlegmator 5. The dephlegmator,

in turn, is connected by a line 6 to a water condenser 7,'the discharge'end of which is connected bya pipe 8 to a receiving tank 9.

A liquid drawoli` line l() from the expansion chamber communicates with a combustion chamber 11 which has a discharge line 12 communicating with the suction side of the pump 13, the latter being connected through a discharge line 14 back to the chamber 3 so that a continual circulation may be maintained between the two chambers.

The oil to be treated is introduced from any convenient source throughi the ipe 15 which is looped through the top of t e combustion chamber 11 to extract heat therefrom and to pre-heat the oil travelin through the charging line. The pre-beate charging stock is directed through the line 15 which is connected to the heating coils2 l by means of a line 16. The oil after being heated toa conversion temperatureV in the heating coils 2 is discharged through transfer line 17 controlled by a valve 18 into the expansion or vaporizing chamber 3. In the bottom of the expansion chamber is maintained a body of molten lead as shown at 19. The oil body is permitted to collect above this molten lead body, the.level being controlled by means of a draw-oil` line 20 controlled by a valve 21 and tricocks 22. The vapors evolved during the conversion of the oil pass off through-the vapor line 4 and are subjected to dephlegmating and condensing actions Vin the separate stages 5 and 7. The condensed vapors are collected as liquid distillate in the receiving tank 9 which is equipped with a pressure relief valve 23,. pressure gauge 24, liquid level gauge 25, and liquid draw-oli' valve 26. The pressure on the system may be controlled by means of the pressure relief valve or differential pressure upon the different stages maintained by the valves 18, 27, and 28 positioned between the different stages. A reiiux condensate separated out in the dephlegmating stagev may be returned through the pipe 29 controlled by a valve 30 and recycled with the stock through the heating sta e. y

During t e conversion of the oil in the expansion or vaporizing chamber 3 there will be separated out finely divided free carbon particles which would normally accumulate in the expansion chamber. Some of this carbon would remain in suspension in the unvaporized oil and be carried oif in the residual products withdrawn from the chamber, while a portion of the carbon would collect in a relatively solid sludgy or coky mass in the bottom of the chamber. To prevent this objectionable carbon accumulation, the free carbon particles which are rained from the oil body during its conversion are collected 0n the surface of the flotation medium or molten lead which is maintained in the bottom of the chamber. This molten lead has a heavier specific gravity than the carbon and for this reason the free carbon will remain upon its surface. This otation medium is withdrawn from the chamber 3 through the line 10 and valve interposed therein and circulated through a combustion chamber 11, into which is introduced a gas such as air through a pipe 31. At the same time through the pipe 32 is withdrawn the. gaseous constituent-s formed by the colnbustion of the carbonaccous particles with the air introduced through the line 31. Valves 33 and 34 are interposed in these lines to regulate the introduction and withdrawal of the gases. It is essential that the-introduction' of air be accurately vcontrolled to prevent too active flow of the liquid. The vaporizing and combustion chambers are preferably' operated at substantially the same pressure, the

--diferential pressure conditions which may be maintained therein being only suflicient to assure the circula-tion of the flotation medium from one chamber to the other and such differential pressure as may be caused by the circulating pump 13.

The advantage of the apparatus is readily appreciated, as the carbon accumulation is practically eliminated, permitting theapparatus to be operated over a considerable period of time without the necessity of shutting down for cleaning the carbon from the expansion or conversion stage.

I claim as my invention: V

1. A process for cra-cking petroleum oil consisting in heating the oil to a conversion temperature, permitting the oil to vaporize while maintaining it in a substantial body above a flotation medium in an enlarged expansion zone, drawing off the carbon separated out during conversion by withdrawing the flotation medium from the expansion zone. removing the carbon from the flotation mediuml by oxidation and recycling the medium back to the expansion stage.

withdrawing the flotation medium, having the carbon supported thereon and subjecting it to an oxidizing action in a separate combustion zone, recycling the carbon free medium back to the expansion zone.

4. A process of converting heavier into lower hydrocarbons, consisting in continuously passing the oil through a heating zone wherein it is subjected to a cracking temperature, in discharging the products of conversion from said heating zone into an enlarged expansion 'chamber where substantial vaporization occurs and carbon is precipitated, in maintaining a. supply of molten 4metal in said expansion chamber on the surface of which, said precipitated car-- bon is suspended, in continuously withdrawing molten metal and the suspended carbon from said expansion chamber and passing it to a. combustion chamber wherein the carbon is oxidized, and in continuously recycling the molten metal free from carbon from said combustion chamber to said expansion chamber.

5. A process for treating oil in which combustible solids separate from the oil, comprising maintaining a body of heated oil in an enlarged chamber, wherein the combustible solids precipitate out of the oil, continuously removing the combustible solids precipitated out of the oilfrom such enlarged chamber, admitting the same to an oxidizing zone, wherein combustion thereof occurs, and imparting the heat given up by combustion of said combustible solids in said oxidizing zone to oil being supplied to the process, to preheat the same.

AUBREY D. DAVID.

2. A process for cracking petroleum oil consisting in hea-ting the oil to a conversion temperature, permitting the conversion to take place in an enlarged expansion chamber containing a molten flotation medium having a specific gravity in excess of the free carbon particles, removing the carbon from the system by continuously withdrawing the flotation medium from the expansion chamber, subjectingit in a separate stage to an oxidizing action and continuouslv recycling the flotation medium devoid gf .the carbon back to the' expansion cham-

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