US2109631A - Conversion of hydrocarbon oils - Google Patents

Description

March 1, 1938. c. H. ANGELL CONVERSION OF HYDROCARBON OILS Original Filed May 16, 1955 av 5m INVENTOR A ENGI IU CHARLES H. ANGELL TTORNEY Patented Ms. 1, 1938 2,109,631

CONVERSION OF HYDROCARBON OILS Charles H. Angeli, Chicago, ni., assignor to Universal Oil Products Company, Chicago, 111., a corporation of Delaware Application May 16, 1935, Serial No. 21,746 Renewed June 5, 1937 7 Claims. (01. 196-48) This invention refers to an improved process together with the vaporous products from the for the conversion of relatively high-boiling hycracking and coking operations with which they drocarbon oils or oils containing a substantial are commingled, while high-boiling components proportion of high-boiling materials wherein the of the charging stock remaining unvaporized by charging stock for the process is subjected to va-- contact with the hot vaporous products of the 5 porization by being 'commingled with hot vaprocess are returned to the reaction chamber and porous conversion products of the process, the thereby subjected to relatively mild conversion, resulting non-vaporous high-boiling components without passing through a heating coil, by conoi the charging stock subjected to relatively mild tact in this zone with the heated products from 10 conversion conditions together with intermediate the heating coil to which the reflux condensate 10 conversion products of the process previously subproduced by fractionation of the vaporous conjected to more severe conversion conditions and version products and low-boiling fractions of the the resulting residual liquid products subjected to charging stock is supplied. coking. It is within the scope or the invention toefl'ect In one embodiment, the invention comprises substantial vaporization of the charging stock 15 subjecting intermediate conversion products 01' in the vaporizing chamber by contacting the same the process (reflux condensate) to conversion in this. zone with either the vaporous conversion conditions of cracking temperature and superatproducts from the reaction chamber or the vamospheric pressure in a heating coil, introducporous products from the coking chamber, 01

ing the heated products into an enlarged reacbot and t e invention contemplates regulation tion chamber also maintained at a substantial oi the extent of vaporization to which the chargsuperatmospheric pressure, separating vaporous ing stock is subjected by regulating the quantity and liquid conversion products in'the reaction of such vaporous products from the reaction chamber, withdrawing the vaporous conversion chamb r and fr m the coking chamber mproducts from the reaction chamber and intromingled with the chargi stock in the Vaporlz- 25 ducing the same into a reduced pressure vaporizing chamber. Any remaining vaporous pr duc s ing chamber to which hydrocarbon oil charging from the reaction chamber and/or from the cokstock for the process is supplied, withdrawing in c ambe i e c ss of those-required non-vaporous liquids, including high-boiling fecting the desired degree of vaporization oi the components of the charging stock, from the charging stock are subjected to fractionation 3o vaporizing chamber and introducing the same together with the vaporous products from the into said reaction chamber wherein they are subv p n n iected to relatively mild conversion together with T e mpanyin ia mm ti dr win the heated products from said heating coil, lus rat s O e p c fic 10ml of pp s in which separately withdrawing residual liquid conversion the inv n i n may h aeeolnplished- Referring products from the reaction chamber, subjecting t0 h r win heating cell i is located W h n the same to additional heating under non-coking a furnace 2 of any suitable form and the oil sup.- conditions and introducing the heated materials plied to t s z e. n the m n to be later more into a coking zone wherein they ar reduced to fully described, is heated therein to the desired 40 substantially dry coke, introducing vaporous conversion temperature preferably at a substan- 4n products from the coking zone into said vaporiza superatmospheric pressure- The heated on ing chamber, subjecting vaporous products from is di charg d from at 6011 I through line 3 the vaporizing chamber to fractionation for the and valve I into reaction chamber 5, 1formation of reflux condensate, comprising said Chamber 5 is also preferably maintained at a intermediate conversion products which are supu st nti l up ratm 'p ri P r which may plied to the first mentioned heating coil, subjectbe substantially the same or somewhat lower than ing fractionated vapors'of the desired end-boiithat employed at the Outl t from t e Precedin ing point to condensation-and recovering the reheating coil. Although 'not indicated in the suiting distillate. drawing, chamber 5 is also preferably insulated so By this method of operation the excess heat n rder to prevent the excessive loss or heat contained in the vaporous products from the therefrom by radiation so that conversion of the cracking and coking operations is utilized to efheated products supplied to this zone is continued fect substantial vaporization or topping oi the therein. In the case here illustrated, separation charging stock, the low-boiling vaporous i'racof vaporous and liquid conversion products is t ons of which a e subjected to fractions-mien accomplished in chamber I, the liquid products as being withdrawn from the lower portion of the chamber to further treatment, as will be later more fully described, while the vaporous products are removed from any desired higher point in the chamber, such as, for example, through line 6, and may be directed, all or in part, through 'alve 1 in this line into vaporizing chamber 8, or regulated portion or all of these vapors may pass from line 6 through line 9, valve 10 and line I l direct to fractionator 30.

Residual-liquid conversion products are withdrawn from the lower portion of chamber 5 through line I3 and valve ll to pump 15 by means of which they are supplied through line l8 and valve I! to heating coil l8.

Heating coil I8 is located within a furnace I9 of suitable form capable of quickly heating the residual liquid passing through the heating coil to a relatively high temperature sufilcient to eflect its subsequent reduction to coke in coking chamber 22, to which the highly heated residual liquid is supplied through line 20 and valve 2|. The velocity of the residual liquid passing through heating coil l8 and the rates of heat transfer in this zone are so regulated that the oil is quickly brought to the desired coking temperature without allowing it to remain in the heating coil and communicating lines for a suflicient length of time to permit any substantial formation and deposition of coke therein.

Coking chamber 22 is preferably maintained at substantially atmospheric or a relatively low superatmospheric pressure although pressures up to pounds, per square inch, or thereabouts, or up to substantially the same pressure as that maintained at the outlet from heating coil l8 may be utilized in the coking chamber. It' will be understood, of course, that although only a single coking chamber is shown in the drawing any desired number of a plurality of such zones may be employed, when desired, and may be either simultaneously operated or, preferably, are alternately operated, cleaned and prepared for further operation so that the coking stage, in common with the rest of the system, may be operated continuously. The heated residual liquid supplied to the coking chamber is reduced to substantially dry coke in this zone and the coke may be allowed to accumulate therein to be removed from the chamber, in any well known manner not illustrated, afterits operation is completed and after it has been isolated from the rest of the system. Chamber 22 is provided with a suitable drain-line 23 controlled by valve Zlwhich may also serve as a means of introducing steam, water or any other suitable cooling material into the chamber, after its operation is completed and after it has been isolated from the rest of the system, in order to hasten cooling and facilitate the removal of coke from the chamber. Vaporous products are withdrawn from the upper portion of chamber 22 through line 25 and may be directed, all or input, through line 26 and valve 21 into vaporizing chamber 8, or all or a regulated portion of the vaporous products, from the reaction chamber may pass through valve 28 in line 25 into line H and thence to fractionator 38.

-Simultaneous with the operation above described, hydrocarbon oil charging stock for the process, preferably comprising an oil of relatively wide boiling range, such as crude petroleum, topped crude or the like, or an oil which contains a substantial proportion at least of high-boiling materials, is supplied through line 3| and valve "that employed in chamber 5 and the charging stock supplied to this zone is directly commingled therein with regulated quantities of the hot vaporous products from reaction chamber 5 and/or coking chamber 22 and is thereby subjected to appreciable vaporization. Suitable contacting means such as bubble trays, packing, perforated pans, bailles or the like (not illustrated) or any desired combination of such means may be employed in chamber 8, when desired, for effecting intimate contact between the hot vaporous prodnets and the charging stock. Contacting of the charging stock with the vaporous conversion products from the reaction chamber and coking chamber in chamber 8, aside from effecting substantial vaporization of the charging stock, serves the additional purpose of partially cooling the vapors and thereby removing therefrom any undesirable high-boiling components such as entrained or dissolved tars and similar heavy liquids unsuitable as charging stock for heating coil I. These undesirable high-boiling components of the vapors commingle in chamber 8 with the high-boiling components of the charging stock which remain unvaporized in this zone and the commingled materials are removed from the lower portion of the vaporizing chamber through line 35 and valve 81 to pump 38 by means of which they are supplied through line 39 and valve 40 to 'reaction chamber 5.

In the particular case here illustrated, the relatively heavy oil fromvaporizing chamber 8 enters the upper portion of reaction chamber 5 and is sprayed against the inner surface of the walls of spreader device indicated at 56. .In this manner the relatively heavy oil flows downward over the walls of the reaction chamber to the lower portion of this zone and is subjected during its passage through this zone to conversion under the conditions maintained in the reaction chamber. The residual liquid products resultingfrom conversion of the high-boiling oils from chamber 8 collect in the lower portion of chamber 5 together with the residual liquids resulting from conversion of the heated products from heating coil and pass therewith to coking, in the manner previously described. The manner of introducing the heavy oils from chamber 8 into chamber 5 and causing the same to flow downward'over the inner surface of the walls of the chamber, aside from accomplishing relatively mild conversion thereof, serves to wash the inner surface of the walls of the reaction chamber and thereby substantially prevent the accumulation of heavy tars and pitch-like material on the walls of the chamber, thereby substantially preventing the formation and accumulation of coke in this zone.

Vaporous products, including the relatively low-boiling vaporized components of the char:- ing stock as well as the components of. the vaporous conversion products supplied vto chamber 8 which tremain uncondensed in this zone, are withdrawn therefrom through line H and valve l2 and! supplied, together-with any portion of the vaporous products from reaction chamber 5 and/or coking chamber 22 not supplied to chamber 8, to fractionation in fractionator 38. The components of the vaporous products supplied to fractionator 30 boiling above the range of the desired final light distillate product of the process are condensed in this zone as reflux condensate, which is withdrawn, in the case here il, lustrated, from the lower portion of the fractionator through line 4| and valve 42 to pump 43, by means of which it is returned through line 44 and valve 45 to conversion, in the manner previously described, in heating coil I.

It is, of course, also within the scope of the invention to separate the reflux condensate formed in fractionator 30 into two or more selected relatively low-boiling andhigh-boiling fractions, any of which may, when desired, be removed from the system while one or more of said fractions may be subjected to conversion in heating coil i and, when desired, other selected fractions may be subjected to independently controlled conversion conditions in one or more separate heating coils, not illustrated, heated products from which may be supplied, all or in part, to reaction chamber 5 or to vaporizing chamber 8 or to coking chamber 22.

Fractionated vapors of the desired end-boiling point are withdrawn, together with uncon'densable gas produced by the operation, from the upper portion of fractionator 30 through line 46 and valve 41 and are subjected to condensation and cooling in condenser 48. The resulting distillate and gas pass through line 49 and valve 50' to collection and separation in receiver 5|. Uncondensable gas may be released from the receiver through line 52 and valve 53. Distillate may be withdrawn from receiver 5| through line 54 and valve 55 to storage or elsewhere, as desired. When desired, a regulated portion of the distillate collected in receiver 5| may be recirculated, by well known means not illustrated in the drawing, to the upper portion of fractionator 30, to serve as a refluxing and cooling medium for as sisting fractionation of the vapors in this zone and to maintain the desired vapor outlet temperature therefrom.

The invention isnot limited to the specific method illustrated and described for reducing the residual liquid products from the reaction cham-' ber to coke since any other well known method, including the use of a suitable heat carrying medium for assisting the coking operation as well as,'when desired, an externally heated coking chamber or a coking retort of any well known form, is readily adaptable to the process of the invention. The invention also contemplates the omission of the coking step of the process, when desired, in which case the process may be operated for the production of liquid residue from the reaction chamber.

The preferred range of operating conditions which may be employed for accomplishing. the objects of the present invention in an apparatus such as illustrated and above described will be approximately as follows: The heating coil to which the reflux condensate is supplied may employ an outlet conversion temperature ranging, for example, from 850 to 950 F., or more, preferably with a superatmospheric pressure at this point in the system of from 100 to 500 pounds, or more, per square inch. Any desired superatmospheric pressure within substantially the same range but no greater than that employed at the outlet from the heating coil may be utilized in the succeeding reaction chamber. The vaporizing chamber is preferably operated at a substantially reduced pressure relative to that employed in the reaction chamber which may range, for example, from 100 pounds, or thereabouts, per

square inch down to substantially atmospheric pressure. The temperature to which the residual liquid from the reaction chamber is subjected in the heating coil to which it is supplied may range, for example from 900 to 1050 F., preferably with a relatively low superatmosphericpressure in this zone of the order of 20 to 150 pounds, or thereabouts, per square inch, although lower or higher pressures may be employed in this zone, when desired. Any desired pressure ranging from substantially atmospheric to 150 pounds, or thereabouts, per square inch, which, however, is no greater than the pressure employed in the preceding heating coil, may be utilized in the coking zone. The pressures employed in the fractionating, condensing and collecting portions of the system may be substantially equalized or somewhat reduced relative to the pressure employed in the preceding portions of the system communicating therewith.

As a specific example of an operation of the invention as it may be accomplished in an apparatus such as illustrated and above described, the charging stock, which comprises a California crude of about 20.5 A. P. I. gravity containing approximately 12 per cent of gasoline fractions boiling up to 400 F. and about 40 per cent of materials boiling up to 572 F., is supplied to the vaporizing chamber which is operated at a superatmospheric pressure of approximately 50 pounds per square inch, the charging stock being therein subjected to appreciable vaporization by contact with the total vaporous products from the coking zone as well as a portion of the vaporous products from the reaction chamber. The remaining portion of the vaporous products from the reaction chamber are subjected, together with the vaporous products from the vaporizing chamber, to fractionation for the formation of reflux condensate. The reflux condensate is subjected in the heating coil to an outlet conversion temperature of approximately 950 F. at a supe-'atmos pheric pressure of about 350 pounds per square inch and the highly heated products are supplied to a reaction chamber maintained at substantially the same pressure. Non-vaporous liquid products from the vaporizing chamber are also supplied to the reaction chamber and sprayed against the inner surface of the walls in the upper portion of this zone. Residual liquid is withdrawn from the reaction chamber, quickly heated in a separate heating coil to a temperature of approximately 1000 F. at a superatmospheric pressure of about 50 lbs. per square inch and introduced into a coking chamber operated at substantially the same pressure wherein it is reduced to substantially dry coke. This operation will produce, per barrel of charging stock, approximately 60 per cent of 400 F. endpoint motor fuel of good antiknock value and approximately 100 pounds of low volatile coke of uniform quality and good structural strength,- the remainder being chargeable, principally, to uncondensable gas.

I claim as my invention:

1. In a process for the conversion of hydrocarbon oils-wherein intermediate liquid conversion products, comprising reflux condensate formed by fractionation of the vaporous conversion products of the process, are subjected to conversion conditions of cracking temperature and superatmosphericpressure in a heating coil and communicating reaction chamber, vaporous and liquid conversion products separated in the reaction chamber, separately withdrawn therefrom and the latter subjected to coking in a separate coking zone, the improvement which comprises with-.

drawing vaporous products from the coking zone and introducing a portion thereof into a vaporizing chamber, supplying hydrocarbon oil charging stock for the process to the vaporizing chamber wherein it is subjected to appreciable vaporization by contact with said portion of the hot vaporous products from the coking zone, withfractionation for the formation of said reflux condensate which is returned to the heating coil for further conversion, subjecting fractionated vapors of the desired end-boiling point to condensation and recovering the resulting distillate.

2. In a process for the conversion of hydrocarbon oils wherein intermediate liquid conversion products, comprising reflux condensate formed by fractionation of the vaporous conversion prod-- ucts of the process, are subjected to conversion conditions of cracking temperature and superatmospheric pressure in a heating coil and communicating reaction chamber, vaporous and liquid conversion products separated in the reaction chamber, separately withdrawn therefrom and the latter subjected to coking in a separate coking zone, the improvement which comprises supplying a portion of the vaporous products withdrawn from the coking zone and a portion of the vaporous products withdrawn from the reaction chamber to a vaporizing chamber, supplying hydrocarbon oil charging stock for the process to said vaporizing chamber wherein it is subjected to appreciable vaporization by contact with said portions of the hot vaporousproducts from the coking zone and reaction chamber, withdrawing non-vaporous liquids from the vaporizing chamber and introducing the same into said reaction chamber wherein they are subjected to relatively mild conversion by contact with the heated products from said heating coil, combining vaporous products from the vaporizing chamber with the remaining portions of the vaporous products from the reaction chamber and coking zone and subjecting the resultant mixture to fractionation for the formation of said reflux condensate which is returned to the heating coil for further conversion, subjecting fractionated vapors of the desired end-boiling point to condensation .and recovering the resulting distillate.

3. In a process for the conversion of hydrocarbon oils wherein intermediate liquid conversion products, comprising reflux condensate formed by fractionation of the vaporous conversion products of the process. are subjected to cona version conditions of cracking temperature and superatmospheric pressure in a heating coil and communicating reaction chamber, vaporous and liquid conversion products separated in the reaction chamber and separately withdrawn therefrom, the improvement which comprises introducing a portion of the vaporous products withdrawn from the reaction chamber into a vaporizing chamber, introducing hydrocarbon oil charging stock for the process into the vaporizing chamber wherein it is subjected to appreciable vaporization by contact with said portion of the hot vaporous products from the reaction chamber, withdrawing non-vaporous liquids from the vaporizing chamber and introducing the same into the reaction chamber wherein they are subjected to relatively mild conversion by contact with the heated products from said heating coil, withdrawing vaporous products from the vaporizing chamber, combining the same with the remaining portion of the vaporous products from the re- 4 action chamber and subjecting the resultant mixture to fractionation for the formation of said reflux condensate which is returned to the heating coil for further conversion, subjecting fractionated vapors of the desired end-boiling point to condensation and recovering the resulting distillate.

4. A process for the conversion of hydrocarbon oils which comprises subjecting intermediate liquid conversion products, comprising reflux condensate formed by fractionation of the vaporous conversion products of the process, to conversion conditions of cracking temperature and superatmospheric pressure in a heating coil and communicating reaction chamber, separating vaporous and liquid conversion products in the reaction chambenseparately withdrawing the same therefrom, heating the residual liquid conversion products withdrawn from the reaction chamber to a high temperature under non-coking conditions, introducing the heated materials into a coking chamber, reducing the same therein to substantially dry coke, introducing regulated portions of the vaporous products withdrawn from the coking chamber and from the reaction chamber into a vaporizing chamber, introducing hydrocarbon oil charging stock for the process into the vaporizing chamber whereby it is subjected to appreciable vaporization by contact with said portions of the hot vaporous products supplied to this zone, withdrawing non-vaporous liquid from the vaporizing chamber and introducing the same into the reaction chamber wherein they are subjected to relatively mild conversion by contact with the y the remaining vaporous products from the reaction chamber and the coking chamber, to fractionation for the formation of said reflux condensate which is returned to the heating coil for further conversion, subjecting fractionated vapors of the desired end-boiling point to condensatio and recovering the resulting distillate.

5. A conversion process which comprises fractionating hydrocarbon vapors formed as hereinafter set forth, heating resultant reflux condensate to cracking temperature under pressure in a heating coil and separating the same into vapors and unvaporized oil in a reaction chamber, removing the unvaporized oil and further distilling the same in a second chamber, contacting a portion of the vapors from the second chamber with charging oil for the process to vaporize a portion of the charging oil, introducing the unvaporized portion of the charging oil to the reaction chamber, supplying vapors from the reaction chamber, the vapors from said contacting step and the remaining portion of the vapors from the second chamber to said fractionating step, and finally condensing the fractionated vapors.

6. A conversion process which comprises fractionating hydrocarbon vapors formed as hereinafter set forth, heating resultant reflux condensate to cracking temperature under pressure in a heating coil'and separating the same into vapors and unvaporized oil in a reaction chamber, removing the unvaporized oil and further distilling the same in a second chamber, contacting a portionof the vapors from the reaction chamber with charging oil for the process to vaporize a portion or the charging oil, introducing the un vaporized portion of the charging oil to the res action chamber, supplying vapors from the second chamber, the vapors from said'contacting step and the remaining portion of vapors from the reaction chamber to said rractionating step, and

finally condensing the fractionated vapors.

- 7. A conversion process which comprises tractionating hydrocarbon vapors formed as hereinafter set forth, heating resultant reflux condensate to cracking temperature under pressure in a heating coil and separating the same into vapors and unvaporized oil in a reaction chamber, removing the unvaporized oil and further distilling the same in a second chamber, contacting a portion of the vapors from the second chamber and a portion of the vapors from the reaction chamher with charging oil for the process to vaporize a portion of the latter, introducing the unvaporized portion 01' the charging oil to the reaction chamber, supplyingthe vapors from said contacing step and the remaining portions 0! the vapors from said chambers to the fractionatingstep, and finally condensing the fractionated vapors.

CHARLES H. ANGEIL.

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