US1774188A - Process and apparatus for treating hydrocarbon oil - Google Patents

Description

Aug. 26, 1930. 1,774,188

PROCESS ND APPARATUS FOR TREATING HYDROCARBON OIL J. DELATTRE-SEGUY 2 Sheets-Sheei l PIJ f H :Ill Q lllll Aug. 26, 1930. J. DELATTRE-SEGUY 1,774,183

v PROCESS AND APPARATUS FOR TREATING HYDROCARBON IL Filedv Jan. 28, 1925 2 Sheets-Sheet 2 61H01 umg Patented Aug. 26, 1930 UNITED STATES PATENT oFFlcE JEAN DELATTRE-SEGUY, 0F CHICAGO, ILLINOIS, ASSIGNOR T0 UNIVERSAL OIL PROD UCTS COMPANY, OF CHICAGOpILLINOIS, A CORPORATION \OF SOUTH DAKOTA PROCESS AND APPARATUS FOR- TREATING HYDROCARBON OIL Application iled January 28, 1925. Serial No. 5,337.

My invention relates to a process of cracking hydrocarbon oils, and more particularly to a process carried out ina tubeand drum type of apparatus.

In the cracking of oil in the tube and drum type of apparatus there has been considerable ditliculty experienced because of the formation and deposition of carbon in the vheating tube or coil. There has also been a tendency to create too large a percentage of lixed gases and to generally produce an objectionable quantity of carbon even in the reaction drum when obtaining a high yield of light distillate. It is the object of my invention to provide a process in which I am enabled to prevent over-cracking of the less refractory constituents of the oil; to provide a process wherein carbon lformation and deposition in the heating coil is substantially eliminated, as well as a process wherein the total quantity vof carbon formed and fixed gases produced are materially lessened.

More specifically, my invention contemplates the superheating of a portion of the generated vapors and the .return of such superheated generated vapors into the body of liquid oil in thereaction drum to maintain such body of oilf'iat the optimum cracking temperature, to agitate this oil and to cause a re-combining of the superheated vaporous fractions with the liquid constituents of the oil to materially increase the reaction and the yield of light distillate and in general to provide a process and apparatus for the economic conversion of heavier into lighter hydrocarbons.-

vout my process. Y

Fig. 2 is a detailed plan view of the carbon separator interposed in thesupeheated vapor line. p

In carrying out the process, raw oil from' any suitable source of supply (not shown) is drawn through the line 1 and forced by the pump 2 through the line to the 'heating coil 7 or by properregulation of the valves 5 and 6 the raw oil may be directed entirely through the line 4 to the top of the ydephlegmator, or the stream of raw oil may be divided, a port-ion `thereof passing directly through the line 3 to the inlet of the heating coil, -while the remaining portion is directed through the line 4 to the top of the deplegmator 18. The oil passing through the coil 7vvdisposed in the furnace 8 heated by the 30 burner 9, is raised to a high temperatures The heated oil constituents are directed from the coil 7 through the transfer line4 13 controlled by suitable throttle valve 14'to the enlarged reaction drum 15, wherein conversion takes place. A- portion of the evolved vapors passes from the reaction drum 15 through the vapor line 16 controlled by valve 17 into the dephlegmating column 18. In this deplegmator the heavier fractions of the vapors are condensed, forming reflux condensate, which is returned through the reflux leg 19`by means of the pump 21 to the raw oil charging line or it may be passed by gravity through the by-pass line 22 by suitably`75 regulating valves 20, 23y and 24. The uncondensed 4vapors pass from the dephlegmator 18 through the line 25 in which is interposed a suitable. throttle valve 25a to the final condenser 26 positioned in a condenser so box 27. The ressure distillate and uncon' densable gas pass from the condenser 26 through the line 28 controlled by valve 29 to the receiver 30. The receiver 30 is provided ywith liquid draw-olf line 31 controlled by S5 valve 32 and with uncondensable gas relief pipe 33, controlled by valve 34, it being, of course, understood that the receiver is provided with suitable liquid level and pressure gauges. I As a further feature of t-he invention the pressure distillate may be drawn off through the line 35 controlled by valve 36 andforced bythe pump 37 lthrough the line 38 to the 'v dephlegmator 18 to 'act .as a dephlegmating 95 and stabilizing medium for the generated vaors. i

The feature of my invention that I regard as most important comprises the withdrawal of a portion of the vapors from the reaction 10( drum 15,.,the super-heating of these vapors and their return to the liquid body of oilin the reaction drum 15. `To accomplish this I provide avapor draw-oif line 39 which communi! cates with the vapor space of the reaction drum 15 and is controlled by a suitable valve 40. This line 39 communicates with a pump or blower 41 which in turn connects to a coil 42 disposed in the upper portion 10 ofthe funrnace 8 in the path of theescaping combustion gases from the furnace. A burner 11 is provided for applying additional heat to this coil 42 in the event it is found to be necessary. The vapors after passing through the coil 42 are directed to a header A. This header A communicates through lines B with carbon separators C, shown more yparticularly in Fig. 2. By suitable regulation of the various valves b the superheated vapors can be passed to any one of t-he carbon separators C interposed in the respective-lines B. Provision is made for directing the vapors to these alternate carbon separators so that in the event that one of the carbon separators becomes charged with carbon it can be cut outl of the system and the run continued by merely cutting in another of the carbon separators, it being understood that the charged separator can be .cleaned while it is'cut out of the system. 4These carbon separators do not specifically form any feature of my invention and are shown merely diagrammatically. They may, however, be provided with a screen such as shown at c. From the carbon separator through which the vapors are being passed they are directed to the comon line 43 con'- trolled by valve 44 and thence to the perforated spray member 45 disposed in the reaction drum 15 well below the normal liquid -level therein. It will be readily apparent that by this means a portion of the generated vapors can be withdrawn from the reaction drum 15, superheated, and returned free of carbon tothe liquid body of oil in sai-d drum. The drum 15 is provided with vertically disposed residuum draw-off lines 46 controlled by suitable throttle valves 47. It will, of course, be understood that the carbon separators C can be-readily. dispensed with. The amount of carbon formed in the superheating of the vapors depends on the characteristics of e the latter and on the degree of superheat given them. Due to the velocity and turbulency of the vapors passing through the s uperheating coil 42, through the line 43 and spray 45, the fine carbon particles are held in' suspension and given no opportunity to adhere to the walls of the tube and will be to a vconsiderable extent carried back into' the reaction drum15.

The particular conditions which will be maintained in the various parts of the apparatus, for example, the coil 7, the drum 15, and the coil 42, and also the proportion of the vapors superheated and re-injected into the reaction drum, will vary depending on the densable gasv was'reduced to 1.3%.

character and nature of the oil being treated.

The nature and character of my process can perhaps be best understood by comparing-it with a process in which no portion of the vapors is passed through the liquid oil in the reaction drum. The following is an example of such a run carried out in my apparatus. A midcontinent fuel oil having a Baume gravity of 25.1 was subjected in the heating coil to a temperature of substantially 880 F., while the temperature in the reaction drum averaged substantially 860 F, The vapors leaving the reaction drum to enter the dephlegmator were at a temperature 0f Asubstantially 850 F. This run was carried out under a pressure of about 150 pounds. Under this process 40% of the charge was converted into gasoline having an end point of 437 F., 25% of the charge was converted into gas oil, while the residuum produced represented 29.5%. AThe uncondensable gas and dry coke amounted to 5.5% of the oil charged. For the purposes of comparison the following run is given, in which a portion of the vapors was withdrawn from the reaction drum 15, superheated, and returned to the liquid body of -oil therein. In this run the same character oil was treated. The temperature to which 4the oil was subjected in the coil was subraised toa temperature of substantiallyv 1100 F. These vapors were in the proportion of about 20% of the amount of the oil passed through the coil by weight. The average temperature maintained in the reaction drum was substantially 850 F. while the vapors leaving the chamber to be directed either into the dephlegmator or into the vapor heating coil were at a temperature of substantially 840 F. LIn carrying out this lastmentioned run 47% ofthe oil charge was converted into gasoline, having substantially .the same characteristics as that produced in the preceding run, 23% of gas oil was produced, the residuum representing 28.7%, While the loss ndry carbon and uncoln- T 1o' production'of dry carbon when a portion `of the vapors was withdrawn from the reaction drum, superheated and returned to that drum, was about one-half as much as was produced when no vapors were so superheated and returnedl In the second run the fuel consumption was reduced about onethird.

I do vnot .fully appreciate all of the reasons for the advantages obtained when a portion of' the vapors is superheated and returned to the liquid oil in theA reaction drum. I do, however, know that this operation when carried out as described gives the improved results. y

It is my belief, however, that these advany from the system-into tages can he explained in part by the law of mass action. The subjection of a` portion of the vapors to the superheat action in the coil 42 has a tendency to additionally crack these' vapors and -to produce therefrom lighter or uncondensable gases and heavier portions or coke, lwhich are normally end products formed in the main cracking zone. The injection of the latter into the reaction drum during the run will, according to the above law, greatly lessen the Aformation of further gas and coke to such an extent as to more than balance the quantities produced\by the additional cracking ofthe va ors.

urthermore, I believe that while it is true that some gases are formed in the passage of the vapors throu h the coil 42, these gases recombine with ractions of the liquid constituents of the oil in the reaction drum 15 and result in the conversion of a greater percentage of the oil into light condensable fractions than can be obtained when vno vapors and gases are returned to the oil body. The 'passinglof the hot vapors and gases through the liquid oil in the,reaction drum 15 makes it possible to maintain the `oil therein at the optimum cracking temlperature without necessitating the application of such a high heat to the oil in the coil:

7 as to cause over-cracking of the less refracl'tory constituents and formation of car/bon therein.

Furthermore, lthis injection of the heated vapors into the liquid oil body keeps the oil in an agitated turbulent condition, maintains the carbon in suspension, and permits its withdrawal from the reaction drum with the residuum. It is well recognized in oil Atreatment that agitation ofthe oil by vapors or gas permits' vaporization of substantial portions of the oilat lo'wer temperatures. In my procesal employthis phenomena .to

increase vaporization in the reaction druml without the necessit of heating the oil in the coil to such a high temperature as will cause coking of the tubes. My experience has also shown that the conversion ofl the oil in the reaction drum is increased and accelerated by injecting heated vapors taken I claim as my invention: i

1. A process for cracking hydrocarbon oil, consisting in continuously passing a stream of oil through an elongated passageway located in a furnace wherein the oil is' hi hly heated, in transferring the highly heate oil from said elongated ,passageway into an enlarged reaction drum wherein a body of oil accumulates and conversionA occurs, 1n pass-' ing evolved vapors from said drum to a de'- phlegmator, in condensing the dephlegmated vapors and collecting the resulting distillate,

in augmenting the conversion" ofthe oil in the oil in the reaction( said drum by withdrawing a" portion of the hot vaporsfrorn the system, superheating such withdrawn vapors and injecting them into the liquid body of oil in said drum, and

in maintaining a superatmospheric pressure on the oil undergoing conversion.

2. In an apparatus for treating hydrocarbon oil, a coil disposed Within a furnace through which oil is adapted to be passed, a transfer line connecting said coil -to an fenlarged reaction drum, means for withdrawing vapors from said drum, means for superheating such vapors and means for re-injecting them into said drum, means for passlng other vapors from said drum to a dephleg mator, means for, condensing the dephlegmatedl vapors and `for collecting the result-v .ing distillate, and means for maintaining a pressure on the oil underaugmenting the conversion of theoil in said zone by withdrawing a portion o f the vapors from said zone, in superheating such withdrawn vapors and returning them to the reaction zone, and in maintaining a superatmospheric pressure on the oil undergoing treatment.

4. A process for converting oil, consisting in passing a stream of oil through a furnace where said oil is heated to a cracking temperature, in transferring the heated oil to an enlarged reaction zone where vaporization occurs, in passing evolved vapors to a dephlegmator, in withdrawing a portion ofthe hot vapors from the enlarged reaction zone, in superheating such Withdrawn vapors and returning them kto the reaction zone, and in maintaining a superatmospheric pressure on the oil stream While bei-ng 'heated and in said enlarged reaction zone.

l5. A process for crackingv hydrocarbon oil,

'reaction zone where vaporization occurs, in

withdrawing a portion of the hot vapors from such zone, in superheating such vapors, and 1n returning the superheated vapors to thereaction zone to percolate through an oil body therein, and in maintaining a superatmospheric pressure on the oil undergoing conversion.

6. A process for cracking hydrocarbon o1l,

'consisting in passinga stream of oil through `a passageway where said oil is heated, inv

transferring the heated oil to an enlarged reloo y action zone where vaporization occurs, Iin l withdrawing a portion of the hot vapors from such zone,'in superheating suchvapors, f

iny returning the Vsuperheated vaporsto the reaction zone to percolate vthrough, an oil fil body therein, inmaintaining avsuperatmospheric pressure on the oil undergoingv conversion, and in subjecting the superhea'ted ed vapors from the reaction zone, and in superheating such withdrawn vapors and then returning the same to the reaction zone to commingle with the hydrocarbon products product -by passing controlled quantities of.

' therein.

8. A process for converting high boiling point hydrocarbonioil into products within vthe boiling range of motor fuels comprising vsubjecting the oil in liquid phase to a temperature within the cracking range, permitting separation of vapors from the unvaporized oil, subjecting portions of the vapors heavier than gasoline thus separated to vapor phase cracking at temperatures in 'excess of 10000 F., thereafter `contacting the vapors with liquid oil undergoing treatment in the process at a lowertemperature to extract heat from the vapors, and additionally cooling the vapors sufficiently to separate therefrom all constituents heavier than the desired 'a cooling medium through the' path of travel of said vaporsand returning the constituents `heavier than the desired product thus obtained to the oily being heated in the liquid phase. A' l 9. A process for converting highboiling point hydrocarbon oil into products within the boiling range of motor fuels comprising subjecting the oil in liquid phase to a temv perature within the cracking range, separating vapors from the unvaporized oil, subjecting vapors heavier than gasoline equal to substantially 20% by Weight ofv the oil treated so obtained to vapor phase cracking,

- at temperatures in excess of 10000 F., thence j pointto'escape therefrom, and returning the collected unvaporized charging oil and concontacting the vapors with liquid hydrocarbon oil undergoing treatment in the process at a lower temperature, thence subjecting the vapors to fractionation in a fractionating column, collecting in said fractionating column charging oil for the process unvaporized by Contact with the vapors and constituents condensed from the vaporsin saidv fractionating column, controlling the cooling effect in said fractionating column to 'permit only vapors condensible into ya product of the desired end densate from said fraetionating. column under a. mechanically applied pressure to.

.the oil being heated .in the liquid phase.

10. A process for converting high boiling point *hydrocarbons into products within the boiling range of motor fuels comprising subjecting the heavy hydrocarbons to a liquid phase heat treatment lin a heating coil at a temperature within the crackingrang'e but not substantially above 750 F. to effect liberation of substantial quantities of vapors therefrom, subjecting a portion of the vapors heavier than gasoline liberated from the oil to vapor phase cracking at a temperature of substantially 11000 F., thereafter immediately passing such vapors in physical contact with liquid hydrocarbons at a lower temperature, thence subjectingI the vapors to fractionation to condensate therefrom all constituents boiling above the endpoint of the desired product, controlling said fractionation by-lowing regulated quantities of a cooling medium through the path of travel of the vapors undergoing fractionation, utilizing chargingoil for the process toassist in the cooling of tlie'vapors, collecting unvaporized portions of the charging oil thus utilized and condensate separated from the vapors during fractionation and passing the thus collected. condensate and unvaporized charging oil .under a mechanically applied pressure to the liquid phase heating coil.

` 11. A lprocess for converting' relatively high boiling point hydrocarbon oils into lower boiling point products within the boiling range of motor fuels comprising passing the relatively heavy hydrocarbon oil through a liquid phase heating coil wherein it is heated to a temperature within the crackingv range but not substantially above 7500 F., separating vapors from theoil'thus heated, passing condensible vapors equal to 20% by Weight of the oil treated thus derived through additional heating elements wherein they are subjected to vapor phase cracking at a temperature of 'approximately 11000 F., thence contacting the-vapors with liquid hydrocarbon oil at a lower temperature, delivering vapors subsequent to contact with the liquid hydrocarbon oil at a lower temperature to a tractionating column, facilitating said fractionation in said fractionating column by passing therethrough a cooling medium, collecting at the base of said fractionating column a quantity of condensate separated from the vapors in the fractionating column and unvaporized portions of charging oil for the process which has been utilized as a cooling medium for the vapors, and 'forcing the col ected unvaporized charging oil and condensate from the base of said fractionating column under mechanically apllU plied pressure through said liquid Y phasein'goil to the primary heat treatment by heating the same in liquid phase to said relatively lower cracking temperature, introducing the charging oil thus heated to an enlarged zone whereinvaporization of lighter products from heavy unvaporized oil occurs, removing one portion of the products vaporized from the unvaporized oil 1n sald enlarged' zone, passingsaid removed portion through a heating element wherein said por- 'said charging oil, removing heavy unvaporized oil from said enlarged zone without returning the same to either of said heat treatments, and taking off additional portions of the vapors separated from the heavy oil in said enlarged zone for subsequent condensation.

13. A process for cracking hydrocarbon oils in which the oil constituents treated are subjected to a primary and a secondary heat treatmentv at relatively lower and higher cracking temperatures in different stages of the process,comprising subjecting the charging oil tothe .primary heat treatment by heating. the lsame in liquid phase to said relatively vlower temperature, introducing the charging oil thus heated to an enlarged zone wherein vaporization of lighter products from' heavy unvaporized oil occurs, removing one portion of the products vaporized from the unvaporized oil in said en-` larged'zone7 passing said removed portion of the vapors through a heating element wherein said portion of the vapors is' subjected to said secondary heat treatmentto effect substantial vapor phase cracking at temperatures of the order of 1000o F. or above, reintroducing the products'subjected to said secondary heat treatment into said enlarged zone to physically commingle with the heated charging oil being admitted thereto from said primary heat treatment, to

` efl'ect'iheat exchangeA between said portion of the vapors and said charging oil to cool saidl portion, and facilltatmg distlllat-ion of said charging oil, removing heavy unvaporized oil from sald enlarged Zone without returningthe same to either of said heat treatments, taking off additional'portions ofthe vapors separated from the heavy oil in said enlarged zone for subsequent condensation, and facilitating the cooling of saidA additional'portion ofthe vapors by causing the same to flow in heat interchange relation with final `distillate produced in the process.

14.An apparatus for cracking hydrocarbon oil comprising an enlarged chamber, a primary and a secondary heating means, means for passing charging oil for the process through said primary heating means, means for delivering ,charging oil from said pri` mary heating means to said enlarged chamber, means for removing heavy unvaporized oil .from said enlarged chamber withoutv returning same to either of said heating means,v means for separately removing from said enlarged chamber different portions of the lighter .products separated in vaporous form Afrom the heavy oil in said enlarged chamber,

means for passing one portion of the products vaporized in said chamber through said secondary heating means, means for elevating said portion in vaporous form to a temperature above 10000 F. in said secondary heating means, means fOr reintroducing the vapor heated in said secondary heating .means vinto said enlarged chamber into physical cont-actv with the oil delivered thereto from said primary heating means, and means for subjecting the portion of vapors separately removed from said enlarged chamber to cooling to effect condensation thereof. A y l15. An apparatus'for cracking hydrocar-y bon oil comprising an enlarged' chamber, a primary and a secondary -heating means, means for passin charging oil forthe process through sai means for delivery charging oil from said primary heating means to said enlarged chamber, means for removing heavy unvaporized oil from said enlarged chamber without returning same to either of said heating means, means for separately removing from said enlarged chamber different portions of the lighter products vaporized from the heavy oil in said lenlarged chamber, means for passing one portion of the lighter products thus removed. through said secondary heating means, means for elevating said portion of the lighter products to a temperature,

primary ,heating means',

llo

above 1000o F. in said secondary heating ,Y

means, means for reintroducing the portion of the light .products heated in said secondary heating-means into said enlarged chamber -means for passing charging oil for the procv ess through said' primary heatin means, means for dehvermg charging oil rom said primary heating means to said enlarged chamber, means for removing heavy unvaporized oil from said enlarged chamber l Without returning same to either of said '5 heating means, means for separately removing from said enlarged chamber diii'erent ortions of the lighter products vaporized rom the heavy oil 1n said enlarged chamber, means including a pump for passing one 10 portion of the previously vaporized products thus removedthrough said secondary heating means, means for elevating said portion to a temperature above 1000o F. in said secondary heating means, means for reintroducin the vapori-Zed products heated in said secon ary heating means into said enlarged chamber into physical contact with the oil delivered thereto from said primary heating means, means for subjecting the portion of the lighter vap-orized products separately removed from said enlarged chamber to cooling to effect condensation thereof, means for. collecting the'fnal distillate, and means including a pump, for returning portions v thereof to actas acooling medium for the vapors.

17. A process for cracking hydrocarbon oils in which the oil constituents treated attain relatively higher and lower cracking temperatures in different stages of the process comprising subjecting the charging oil in one stage of the process to temperature conditions adequate to cause the charging oil to attain said relatively lower cracking temperature While substantially in `liquid phase,

n collectinga body of the lcharging oilvin a reaction and vaporizing zone, taking olf a part of the constituents'vaporized in said reaction and vaporizing. zone subjecting said 4'0 part of the constituents to vapor phase cracklng at temperatures of 1000o F. or above, reintroducing the vapors so subjected to vapor phase cracking into said reaction and vaporizing Zone to commingle with the unvaporized oil therein and impart heat thereto, to

. facilitate conversion and distillation of the charging oil in the reaction and vaporizing Zone, removing residual oil from saidreaction zone without further heat treatment in 5o the process, separately taking off from saidreaction and lvaporizing zone a second part of the constituents vaporized therein and subjecting said second part of 1Jsaid constituents to condensation.

l JEANy DELATTRE-SEGUY. l

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