US2119818A - Apparatus and process for treating hydrocarbon oils - Google Patents

Description

June 7, 1938. KIRSCHBRAUN APPARATUS AND PROCESS FOR TREATING HYDROCARBON OILS N H-uHl l l l l l h-Hll l U IHWI I H U l l l H pa l h Original Filed Ap Patented June 7, 1938 UNITED STATES APPARATUS AND PROCESS FOR TREATTN HYDROOABBON OILS Lester Kirschbraun, Chicago, Ill., assignor, by

mesne assignments, to Universal Oil Products Company, Chicago, 111., a corporation of Dela- Application April 1, 1920, Serial No. 370,468

Renewed May 26, 1927 19 Claims.

My invention relates to improvements in an apparatus and process for treating hydrocarbon oils 'and refers'more particularly to a differential pressure process for the converting of 5 heavy hydrocarbon oils into lighter oils of th character of gasoline or the like;

Among its salient objects are to provide a process in which the oil is subjected in succeeding steps to different pressures and temperatures, It} the limits of same being controlled to maintain the oil under the most advantageous cracking conditions; to provide a process in which the oil vapors passing through the stages of the process are dephlegmated in each stage by being passed 15 through the residual oil before finally being directed to the condenser, thereby producing a more uniform distillate; to provide a process in a which the precipitated carbon is prevented from settling in the bottom of the separate retorts so which constitute the stages of the process due so vation of the apparatus used to carry out this process.

Referring to this drawing, the raw oil is introduced to the supply pipe I- from any convenient source and is forced into the cracking 35 tubes 2 through the pump 3 and charging pipe 4, which is controlled by valve 5 The oil in the tubes is subjected tov heat in the furnace .3, the heat being supplied by means of an oil burner I. The cracked oil is directed from the 40 cracking tubes through the lines 3, 8a, 8b and to controlled by valves 3, 312, 3a, 3b and 3c respectively to a series of connected retorts III, II, l2 and i3.' These retorts are connected by the lines 14, II and ii, in which are interposed the valves 45 H. II and I3. The ends of these pipe lines are upturned at a, lid. and Ila to form open ended stand-pipes in each 'of the retorts. An open ended stand pipe 23 extends up into the retort l3 and furnishes a residuum drawofl from this. 5

50 final stage of the apparatus. This drawofl pipe 23 is controlled by a valve 2i,

In each of the succeedingrtoits, it will be noted that the standpipe extends a little higher into'the retort and retains-the residual oil at a s5 somewhat higher level. The vapors generated in the retort l rise into the vapor line 22 and are dephlegmated in the aerial 23. From this aerial the uncondensed vapors are directed out through the line. 24, while the distillate is returned to be retreated in the cracking tubes through the secondary connecting line 25, which is controlled by a valve 26 and the return line 21, controlled by valve 23 and the pump 3. The natural course ofthe vapors, fter passing into the line 24, assumingthe valve 9, closed, is down through the injector line 30, controlled by valve 3| into the residual oil of the nei'it succeeding re-, tort II. The lower part of this injector line is perforated, thereby permitting the vapors to be difiused in small streams through the residual 011. I

The passing of these vapors through this liquid subjects them to further dephlegmation and assists in the vaporization qr any lighter hydrocarbons which may be contained in the residual 'oil'of this retort. The vapors or gasses bubbling up through the liquid pass out through the top of the retort ll, through the line 32 and are again subjected to the condensing action of the dephlegmator 33 located above theretort ll. As previously explained, the vapors pass oil intothe line 24 and the distillate is returned to the cracking tube. With the valves 23, 34, 36, in a closed position and valve 33' in an open position, and the vapors taking their normal course, they will so be directed as explained through each of the successive retorts, being subjected to a dephlegmatory action both in the aerials 23, 33, 34a and 33 and in= the residual oil in retorts Ill, .12

and I3 and finally pass over from the final serial :5 r 33 through'the gooseneck 43 to the water condenser and receiver 42. The distillate con-' densed in theaerials is tapped oil to be returned through the pipe 21 to the cracking tubes, as explained inv the case of the aerial 23, which is located above the first retort Hi.

The condensate from the dephlegmators instead of being returned to the cracking tubes through the line 21 may be directed to the retorts throughthe connecting pipes 33, 43.- 31 and 46' 33 which areregulated by the-valves 63. II, II

- and 12. Valves I3, l4, l5 and l4 in the distillate return line 21 and valves 22, 23a and 23b in pipes 25, 2la and 23b furnish additional means for controlling the disposition of the condensate 60 from the dephlegmator. I

Tomaintain the residual oil-in the 'retorts'at a proper height, it may be necessary to pump the oil from one stage to another and for this purpose, I mount the pumps, 43, 44 and 45 between I the respective retorts and connect them with the retorts in such a manner that pump 43 may draw oil from the retort I through the inlet line 46 controlled by valve 41 andsupply the same to the retort H through the line 48, controlled by valve 49; or by closing the valve 49, the retort ll may be cut out and the residual oil supplied to the retort I2 through the line 50, which is controlled by valves 5i and 52. The pump 44 in the same way may draw a supply of residual oil through the inlet pipe 53 controlled by valve 54 and supply the same to the retort l2 through the line 50, or if the valve 52 be closed, the retort l2 may be cut out and the residual.oil supplied to the retort l3 through line 51 regulated by valves 58 and 11. The pump 45, taking its charge of residual oil from the retort I 2 through the line 55, controlled by valve 56, supplies the same to the retort 13 through line 5.! controlled by valve 58. The height of the residual oil in each of the retorts may be regulated either by the system of pumps or by the valves l1, l8 and lainterposed in the standpipe lines.

The receiver for collecting the final distillate is fitted with the usual type-oi pressure gauge 59, pressure relief valve 60, liquid gauge 6i and drawoff pipe 62 controlled by a valve 63. By causing the gases to pass through a series of aerials, and bubble up through the residual oil in the retorts, the final vapor is thoroughly dephlegmated. This agitating of residual .oil in the respective retorts by passing vapors therethrough tends to keep the precipitated carbon caused'by the cracking of the oil in suspension in the retorts and obviates, to a great extent, the difilculties of having this precipitated carbon deposited upon the interior of the retorts and vapor lines. The controlling of the amount oi residual oil relative to the volume of gases in the respective retorts, together with theabsolute' control of the pressure commensurate with the temperature provides a combination by means of which the character of the final distillate may be positively controlled.

If desired, the heating gases'from the furnace may be directed by means of a duct 64, to the differentretorts to offset to a certain degree, the heat lost through radiation in the retorts and vapor lines.

It will be noted that with the arrangement of the valves (as shown) in the inlet, vapor distillate return lines from the 'dephlegmators and the residuum or condensate control lines to the respective retorts, one or more of the retorts may be cut out of the system at any time to be cleaned orrepaired.

In the cracking off hydrocarbon oils, in the process above explained the oil on entering the first retort is at a high temperature and highpressure. In this first expansion or cracking zone,

vapors will be released from the body of the oil commensurate with the temperatureand pressure maintained in said zone. That portion of the oil which is directed to the succeedingretort will be subjected to a temperature somewhat lower than the temperature in the initial stage and a correspondingly decreasing pressure. Here again, oil vapors which would be released under such conditions are freed from the oil and are subjected to identical conditions of dephlegmation as those released from the'initial stage except that after passing through theaerial condenser they are injected into the body of the oil in a succeeding retort where the temperature oi! the oil is somewhat lower; on, in each succeeding-stage. the

decreasing pressure maintained therein releases oil vapors having a higher end point. From the -final stage we have a combination of these vapors injected through the oil body and directed to be condensed and collected as a distillate in the receiving tank.

As an illustrative run, I will heat gas oil from the midcontinent field of from 32 to 34 Baum to a temperature of about 850 F. in the heating coils and admitting the same to the initial stage. where a pressure of pounds is maintained upon the oil. For eflicient operation and for procuring a greater yield of oil, I find that the succeeding temperatures in the stills ll, l2 and I3 are roughly 750, 700 and 650 F. respectively. The pressure in each stage decreases from 25 to 50 pounds. Under such conditions a yield of 50% distillate may be obtained from which I have been able to procure by redistillation, about 80% of 400 F. end point gasoline.

I claim as y invention:

1. A continuous process for treating hydrocarbon oils, comprising subjecting the oil to heat in a cracking zone to be heated to a cracking temperature, in passing the oil through successive vapor releasing chambers of diminishing temperatures and pressure, in removing reflux condensate from the vapors produced in each vapor releasing chamber, and in passing the vapors produced in one vapor releasing chamber through a. body of oil undergoing treatment at a cracking temperature in the succeeding vapor releasing chambers of lower temperature and pressure and in finally discharging the vapors ior condensation and collection.

2. A continuous process for treating hydrocar bon oiL consisting in subjecting the oil to heat in a cracking zone, in passing thecracked oil through successive vapor releasing chambers of decreasing temperature and pressure, dephlegmating the oil vapors from one of said vapor releasing chambers by passing the same through a body of unvaporized oil at a cracking temperature in the succeeding chamber, drawing off and condensing the vapors from the final vapor releasing chamber.

3. A continuous process for treating hydrocarbon oil, consisting in subjecting the oil to heat in bon oils, consisting in subjecting the oil to a 1 cracking temperature in a heating-zone, in passing the highly heated oil through zones wherein successively decreasing temperatures and pressures are maintained, -in dephlegmating 'the'oil vapors generated in the respective series by in.-

jecting the same into the bodies'ot theunvaporized oil in the succeeding zones and by passing them through successive 'dephleg'mating towers.

at least one oi said bodies being at afcracking temperature,- in returning selected portions of the resulting reflux condensate through the heating zone, and in collecting and subjecting the vapors from apredetermined zone to condensation.

5. A continuous process'for treating hydrocarbon oils, consisting in subjecting the oil to a cracking temperature in a heating zone, in directing the heated oil constituents through zones of decreasing temperature and pressure, in dephlegmating the oil vapors generated in the respective zones by passing them into the bodies of the unvaporized oil in the succeeding zones, at least one of said bodies being at a cracking temperature, in maintaining the carbon in suspension by agitating the oil in each zone with such vapors from the preceding zone, in further dephlegmating the vapors by passing them through successive dephlegmating towers, in returning selected portions of the reflux condensate resulting from such dephlegmation for re-treatment in the heating zone, and in subjecting the vapors from the final zone to condensation, and in collecting the resulting distillate.

through the body of oil in a succeeding chamber and drawing oil and condensing the vapors issuing from the final releasing chamber.

'7. A continuous process for treating hydrocarbon oil comprising subjecting the oil to heat in dephlegmating action and returning reflux condensate obtained thereby to the cracking zone for retreatment.

8. Apparatus for cracking hydrocarbon oils comprising a heating coil, a battery of stills, means for selectively charging oil from the coil to the several stills, means for condensing a portion of the vapors from the stills, and means for selectively admitting condensate to the several stills.

9. Apparatus for cracking hydrocarbon oils comprising a heating coil, 9. battery of stills, means for selectively charging oil from the coil to the several stills, condensing means in connection with the stills, means for conducting condensate from said condensing means and selectively admitting same to the stills severally, and means for selectively drawing ofl. liquid from'the lower portion of the stills.

10. Apparatus for cracking hydrocarbon oils comprising a plurality of stills, vapor equalizing and liquid level lines interconnecting the stills in series, means for introducing oil to the stills comprising a manifold line with valved branches to the several stills adapted to selectively admit the oil to the stills severally, a reflux condenser adapted to receive vapors from the stills and means for returning condensate from said reflux condenser to the several stills comprising a maniiold line with valved branches to the several ing chambers of the series, means for taking oiI vapors Irom each of said chambers, means for passing vapors taken from a preceding chamber through a succeeding chamber, means for subjecting vapors issuing from the last ofsaid series of chambers to condensation, and means for maintaining a superatmospheric pressure on the oil undergoing treatment in the apparatus.

12. An apparatus for cracking hydrocarbon oils comprising a heating means, a plurality-of vapors from a preceding. chamber into the lower portion of a succeeding chamber, means for sub- .iecting vapors issuing from said serially connected chambers to final condensation, and means 'for maintaining controlled pressure conditions on the oil in each or said serially connected vapor re leasing chambers.

13. A processor distilling oil comprising heating a heavy hydrocarbon oil under pressure to a cracking temperature while it is being circulated in a stream, discharging the heated oil into an enlargedchamber while maintaining the pressure therein to separate vapors fromthe oil, continuously leading the vapors. and the oil in separate streams from the chamber into a body of oil maintained at a cracking temperature and pressure, bringing the vapors into direct contact with the oil of the bodyand leading off. vapors from the body and condensing them. 1

14. A conversion process which comprises heatingheavy hydrocarbon oil to cracking temperature under. pressure while flowing in a restricted stream, discharging the heated oil into an en,- larged chamber maintained under superatmospheric' pressure and separating vapors from unvaporized oil therein, continuously removin 1 vaporized oil from said chamber and maintaining a body thereof at a cracking temperature in a second chamber, continuously removing vapors from the first-named chamber and introducing the same into said body in the second chamber,

and removing vapors from the secondchamber and condensing the same.

15. A conversion process which comprises heating heavy hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream, discharging the heated oil into an enlarged chamber maintained at cracking temperature and under superatmospheric pressure and therein separating vapors from unvaporized oil, continuously removing separate streams of vapors and unvaporized oil from said chamber and introducing the same to a second chamber main- ;the second chamber and condensing the same.

16. A conversion process which comprises heating heavy hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream, discharging the heated oil into an en-' larged chamber maintainedat cracking temperature and under superatmospheric pressure, simultaneously distilling a body of oil at a cracking temperature in a second chamber maintained under lower pressure than the first-mentioned chamber, separately removing vapors and unva- 15 .por releasing chambers, means for introducing in an enlarged chamber maintained under presporized oil from the flrst mentioned chamber and introducing the same into said body of oil in the second chamber, and removing. vapors from the second chamber and condensing the same.

17. A conversion process which comprises heating heavy hydrocarbon oil to cracking temperature under pressure in a heating zone and separating the same into vapors and unvaporized oil sure, removing unvaporized oil from the chamber and distilling a body thereof at cracking temperature in a second chamber, separately removing vapors from the first-mentioned chamber and dephlegmating the same to condense heavier fractions thereof, returning resultant reflux con-. densate to the heating zone, introducing lighter fractions of the vapors uncondensed by said dephlegmation into said body of unvaporized oil in the second chamber, and removing and condensing the vapors from the second chamber.

18. A conversion process which comprises heating hydrocarbon oil to cracking temperature un.-

der pressure in a heating zone and separating the same into vapors and unvaporized oil in an enlarged chamber maintained under cracking conditions of temperature and pressure, removing unvaporized oil from the chamber and maintaining a body thereof in a second chambermaintained at lower cracking temperature and pressure than the first-mentioned chamber, separately removing vapors from the first-mentioned chamber and dephlegmating the same to condense heavier fractions thereoL'returning resultant reflux condensate to. the heating zone, introducing vapors uncondensed by the dephlegmation into said body of unvaporized oil in the second chamber, and removing and condensing the vapors from the second chamber.

19. A conversion process which comprises'heating heavy hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream, discharging the heated'oil into an enlarged chamber maintained under cracking conditions of temperature and super-atmospheric

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