US1615407A - Continuous distillation of crude petroleum oils - Google Patents

Description

oct. 11.1924 Y F. M. ROGERS ET AL CONTINUOUS DIS'ILLATION OF CRUDE PETROLEUM OILS .NNN

Jan. 25, 1927'.

Patented Jan. 25, 1927.

UNITE STATES FRANCIS M. ROGERS, 0F WI-IITING', INDIANA, AND ROBERT E. WILSON, OF CHICAGO, ILLINOIS, ASSIGNORS TO STANDARD OIL COIVIYANY, OF IVI-IITING, INDIANA, AND CHICAGO, ILLINOIS, A CORPORATION OF INDIANA.

CONTINUOUS DISTILLATION OF CRUDE PETROLEUM OILS.

Application lerl October 11, 1924. Serial No. 743,001.

The present invention relatesto `improvements in the continuous distillation of crude petroleum oils, and will be fully understood from the following description, illustrated by the accompanying drawings, in which the figure shows diagrammatically apparatus suitable for carrying the invention into effeet.

Referring to the drawing, the numeral 5 indicates the end stills of a battery or series ot continuous stills, such as are ordinarily employed in the continuous distillation of 'petroleum oils with fire and steam. From the last ot the battery of continuous stills the heated residuum Iis discharged or pumped into the coil 7 mounted in a suitable setting 8, the coil of the usual cleanable form, and its setting being shown diagrammatically in the drawing. Steam or other inert gas may be introduced into the coil through the valve line 9, communicating with the inlet of the coil. From the coil oil passes through a line 10, preferably of greater cross-sectional area than the coil 7, and into a vaporizing chamber or drum 11. The vaporizing drum 11 may be provided with a suitable device or separator 12 for removing entrained liquid from outgoingv vapors. The separator 12 communicates with the vapor pipe 13 leading to the condenser coil 14, from which condensate passes into a receiving drum 15, in

which a separation of oil and water maytake place. Oil may be withdrawn through the valved discharge line 16 and water may be withdrawn through the discharge line 17. From the vapor space of the .receiving drum 15 a line 18 communicates With the vacuum pump 19.

Residues are removed -from the vaporizing drum 11 through the valved line 20, which communicates with the intake ot the hot oil or surge pump 21. In carryn out the invention, a crude or equivalent oi such as reduced crude oil, is

reduced with fire and steam to a suitable bottom, say up to 20% and preferably 10 to 15% of the crude, in the battery of continuous stills by meansA of lire and steam. The temperature prevailing in the last of the stills 5 may be from 600 to 6500 F. The residue passes through the pipe 6 into and through the heated coil 7, steam being added in the quantity desired to the steam inlet pipe 9. The proportion of steam employed varies with different oils and with the character of overhead distillate desired. In general, from 1 to 10 pounds of steam per gallon of distillate are employed, but this may be .varied within wide limits, depending on the vacuum employed, the nature of the crude and product desired, etc. In passing through the coil 7 the oil is brought to a higher temperature, say 700 to 800O F. and preferably 'from 720 to 7 500 F. From the coil 7 the oil and steam are drawn into the enlarged pipe 10, which is preferably of considerable length, so as to permit the attainment of substantial equilibrium between vapors and liquid. The heated oil, oil vapors and steam then enter the separating drum 11, in which separation of vapors from oil residue takes place. The vapors pass out through the entrainment separator 12 and vapor line 13, the entrainrnent separator 12 removing entrainment particles of oil and consequently discoloration or other impairment of the distillate. The separated vapors then pass into the condenser 111, from which condensate flows to the receiver 15. In the receiver, condensed water and oil may suitably be separated.

The vapor space of the receiving drum 15 is connected with the vacuum pump 19, by which a suitable .vacuum is maintained in the separating drum 11. An absolute vpressure of from1 to 3 inches of mercury or up to 4t inches may suitably be maintained in the separating drum by the vacuum pump.

The residue in the separating drum, While still in liquid state, is drawn out through the valved line 20 by the .pump 21. This residue may vary from 20 to 50% on the residuum discharged from' the last of the. continuous stills, or from 2 to 6% on the original crude in the case ot' mid-continent crude. With other crudes, these proportions may vary, in

the original crude and had' a melting point a stock for @racking into gasoline, if so de-V sired. l

7e claim: f' 1. The method of continuous distillation of crude petroleum oils which comprisesV reducing the oil to a very heavy bottom by subjecting the oil to the action of heatand steam, passing said very heavy bottom, acb companied by' steam, through `a confined passage in a heat-ing zone at a temperature y sufiicient to bring the oil toa temperature of 70() to 800 Fl, introducing the heated oil and steam4 into al chamber' in which separation of vapors and liquids takes place, separately removing the vapors and liquids therefrom, and maintaining Within said chamber absolute pressure of. less than 4t inches of mercury."

2. The method of reducing' crude petroleum oils comprising subjecting a petroleum oil to distillation with fire and open steam to bring said oil toa very heavy residue amounting to not over" 20% on-thee origina-l crude, lpassing sai-1d- -res1due, accompanied by steam, through a confined pas- 3. The `method ot reducing crude petroi leum oils comprising subjecting' mid-con= tinent petroleum oil to distillation with fire and 4Steam to bring said oil to va pitchbot-= tom o- 1() to 15% of the original crude, passing said bottom, accompanied by steam, through a confined passage in a zone heated 'to bring the temperature-of the oil tol/720 to 750 F., introducing the heated oil and steam into a chamber iii-which an abselute pressure of 1 to '3 inches'of mercury' is maintained, and removing vapors' and `unvaporized residue separately .therefrom FRANors Roor'mrs.y ROBERT WILsorr

Images