US2067810A - Treatment of hydrocarbons - Google Patents

Description

Jan. 12, 1937. c, H. N E L' 2,067,810

TREATMENT OF HYDRQGARBONS Original Filed Feb. 11, 1932 CONDENSER FURNACE CHARLES H. ANGELL.

Patented Jan. 12, 1937 UNITED STATES TREATMENT OF HYDROCARBONS Charles H. Angel], Chicago, 11]., assignor, by mesne assignments, to'Universal Oil Products Company, Chicago Ill ware Application February 11,

Renewed April 27, 1934 a porporation of Dela- 1932, Serial No. 592,231

Claims. (01. 196-56) This invention relates to the treatment of hydrocarbons for the simultaneous conversion of hydrocarbon oil and solid bituminous material.

It is an object of the present invention to pro- 5 vide for the conversion of hydrocarbon oil accompanied by further conversion of the resulting residual liquid product together with added solid carbonaceous material such as coal for the production of substantially devolatilized coke, desirable light distillate such as motor fuel of high antiknock value, and incondensable gas.

In the preferred embodiment of the present invention conversion of the oil and the formation of residual liquid is preferably effected at substantial super-atmospheric pressure and the residual liquid is withdrawn from the reaction zone of the cracking system without substantial loss of heat and is subjected, together with coal or similar added solid bituminous material, to continued conversion, coking and substantial devolatilization at reduced pressure. In this manner the heat attained by the residual liquid in the cracking operation is utilized to assist its own further treatment and treatment of the added solid bituminous material, at the same time permitting primary conversion of the oil and the subsequent coking operation each under the most suitable conditions; substantial super-atmospheric pressure, which favors the desired type 30 of conversion of the liquid charging stock, being employed in the primary conversion stage of the system while lower pressures down to substantially atmospheric, which favor coking and devolatilization, are employed in the coking stage.

Aside from the heat recovered from the residual conversion products and utilized to effect coking of the added bituminous material by direct admixture therewith, further use is made of the conjointly operated oil conversion portion of the system by utilizing incondensable gas resulting therefrom as a heat carrying medium to assist conversion and coking of the mixture of residual oil and bituminous material and to effect substantial devolatilization of the coke produced. In this manner external heating of the coking zone or other means of applying heat externally to the coal and oil mixture is avoided and it is also unnecessary to resort to partial combustion for the material undergoing coking to obtain the heat required for the operation. The advantages of the features of the present invention will be readily apparent to those familiar with the ineflicient methods of coking and carbonization generally employed.

The invention, in one of its more specific embodiments, may comprise subjecting a hydrocarbon oil to conversion conditions in a heating element, introducing the heated products into an enlarged reaction zone maintained at substantial super-atmospheric pressure wherein vaporous and residual non-vaporous conversion products are separated, subjecting the vapors to fractionation, returning the relatively heavy insufficiently converted components of the vapors condensed by said fractionation to the heating element for further conversion, subjecting the relatively light vapors resulting from fractionation to condensation and collecting'the resulting distillate and incondensable gas, withdrawing residual liquid from said reaction zone without substantial loss of heat, and subjecting it, together with added solid bituminous material such as coal, to further conversion and coking in a zone of reduced pressure, subjecting said incondensable gas to'heat in a heating element and introducing it into direct contact with the mixture of residual oil and solid bituminous material at a temperature suflicient to insure converison and coking of the mixture and substantial devolatilization of the coke produced. Vapors from the reduced pressure coking zone may be subjected to fractionation together with vapors from the reaction zone of the oil conversion stage of the system or they may be separately subjected to fractionation followed by condensation, cooling and collection of their desirable light liquefiable components, in which latter case the relatively heavy insufiiciently converted components of the vapors resulting from coking, which are condensed by said separate fractionation, are preferably returned to the heating element to. which the raw oil charging stock is supplied, for further conversion.

Incondensable gas resulting from separate fractionation of the vapors from the coking zone, when employed, may be withdrawn from the system or returned, in part, to be reheated to serve as a heat carrying medium for the coking operation and may, when desired, first be subjected to scrubbing or absorption for the removal of desirable liqueflable components.

One specific form of apparatus suitable for the accomplishment of the process of the present invention is illustrated in the attached diagrammatic drawing. The following description of the drawing embraces a description of the operation of the process of the present invention as it may be practiced in the apparatus illustrated.

Raw oil charging stock supplied through line I and valve 2 to pump 3 may be fed through line 4 and valve 5 to fractionator 6 wherein it is preheated by direct contact with the ascend- 5 ing vapors in this zone assisting their fractionation and passing together with their relatively heavy components, which are condensed in the fractionator, through line I and valve 8 to pump 9. Pump 9 supplies the combined raw oil and 10 reflux condensate from fractionator 6 through line l0 and valvell to heating element [2. It

will be understood that, when desired, a portion or all of the raw oil instead of passing to fractionator 6 may be subjected to preheating by any other suitable means or may-be supplied directly to heating element l2 by well known means, not illustrated in the drawing.

Furnace l3, enclosing heating element l2, supplies the heat required to raise the oil passing therethrough to the desired conversion temperature'preferably at a substantial super-atmos pheric pressure. The heated oil is discharged through line l4 and valve l5 to reaction chamber I6, also preferably maintained at a substantial super-atmospheric pressure. Vaporous conversion products and residual liquid are separated in chamber I6. The vapors pass through line I! and valve I8 to fractionator 6 from which their relatively heavy insufiiciently converted components are returned to retreatment in'heating element l2, as already described. The relatively light components of the fractionated vapors pass through line, I9 and valve 20, are subjected to condensation and cooling in condenser 2|, forming distillate and incondensable gas which pass through line 22 and valve 23 to be collected in receiver 24. A portion of the incondensable gas may be released from the receiver through line 25 and valve 26 and distillate may be withdrawn through line 21 and valve 281. A portion of the distillate from receiver 24 may,-if desired, be withdrawn therefrom and recirculated, by well known means not illustrated in the drawing, to the upper portion of fractionator 6 to assist fractionation of the vapors in this zone.

Chambers 34 and 34' are carbonizing and conversion zones. One or a plurality of such chambers may be used and they may be operated simultaneously or one or more chambers may be in operation while one or more are being cleaned and prepared for operation, thus permitting prolonged operation of the process. The chambers may be filled or partially filled with coal or other solid bituminous material prior to their operation or, preferably, by means of any suitable continuous or intermittent charging device, for example, such as indicated at 35 and 35', coal may be supplied to the chambers during their operation. Residual oil from chamber It withdrawn through line 31 and valve 38 may be introduced into chamber 34 through line 39 controlled by valve 40 and into chamber 34' through a similar line 39' controlled by valves 5 48'. Any desired portion of this residual product may be withdrawn from the system to storage or to further treatment, as desired through .line 4| and valve 42. As an alternative, both vapors and liquids may be withdrawn from chamber I6 through line 31 and introduced to chambers 34 and 34.

All or at least a substantial portion of the incondensable gas from receiver 24 may be directed from line 25 through line 45 and valve 46 .to

7 pump 41 from which it is fed through line 48 and valve 49 to heating element 58. Heating element 50 is located in any suitable form of furnace 5| and the heated gases may be discharged through line 52, line 53 and valve 54 into chamber 35 and from line 52 through line 53' and 5 valve 54' into chamber 34'. The vapors are heated in heating element 50 to a temperature sufiicient to insure substantial conversion and coking of the mixture of coal and residual oil with which they are directly contacted in the coking zone. 10 Preferably the temperature of the gases is also sufiicient to cause substantial devolatilization of the coke produced and further conversion of at least the-relatively heavy components of the volatiles evolved. 15 Chambers 34 and 34' are provided respectively with drain lines 56 and 56' controlled respectively by valves 51 and 51 for the purpose of removing any liquid which may accumulate in the bottom of these zones. Vapors are with- 20 drawn from chamber 34 through line 60 and valve GI and from chamber 34 through line 68' and valve 6| passing from either or both chambers, as the case may be, into line 64. The vapors may then pass through line 64 and valve 5 66 to fractionator 6, undergoing thereafter the same treatment as that afforded the vapors from chamber H5, or these vapors may pass through valve 61, in hne 64, to fractionator 68 where they are subjected to separate fractionation. 30

- Any desired cooling medium, such as a portion of the raw oil charging stock or distillate from the process, may be introduced into fractionator 68 through one or a plurality of lines 69 and valves 18. The relatively heavy components of the va- 35 pors which are condensed in fractionator 68 pass through line H and valve 12 to pump I3 from which they are fed through hne l4 and valve 15 into line It] and thence to heating element l2 for further conversion. Preferably fractionation 40 is so controlled in fractionator 68 that the deing this are well known and are not illustrated in the drawing.

When desired, a portion of the gas from the coking operation may be diverted from line 8| 5. through line 83 and valve 84 to pump 85 or may be supplied to pump 85 by well known means, not illustrated, from the scrubber or absorber in case such equipment is utilized. The gas thus supplied to pump 85 is directed through 60 line 88 and valve 81 to heating element 50, serving to augment the supply of gas from receiver 24 to this heating element and serving as a heat carrying medium for the coking operation.

The light distillate product of the coking operation may be withdrawn as one or a plurality of side streams from fractionator 68 through any or all of a plurality of :hnes l6 controlled by valves 11. The distillate is cooled in cooler 18 and may pass therefrom to storage or elsewhere, 7

as desired, through hne 19 and valve 80.

Substantial super-atmospheric pressure of the order of to 500 pounds or more per square inch is preferably employed in the heating element and reaction chamber of the oil conversion 75 2,067,810 3 portion of the system and this heating element preferably utilizes an outlet temperature rang- .ing from 850 to 1000 F.,.depending primarily upon the type of charging stock employed. The coking zone is preferably maintained at a relatively low pressure of the order of substantially atmospheric to 100 pounds per square inch. The gas heating element may be maintained at any desired pressure ranging from substantially atmospheric to 500 pounds or more per square inch super-atmospheric. The gas is preferably heated to a temperature suificient to maintain the coal and oil mixture in the coking zone, with which the heated gases are directly contacted, at a temperature of the order of 850 to ,1100 F., and preferably not less than 900 F. The fractionating, condensing and collecting portions of the system may be maintained at substantially the same or somewhat lower pressure than that employed in the preceding portions of the system.

As a specific example of the operation of the process of the present invention, a 23 ARI. gravity Mid-Continent fuel oil is the liquid charging stock supplied to the cracking system.

It is subjected, together with reflux condensates, from both the cracking and coking operation, to a temperature of about 900 F. under a pressure of approximately 300 pounds per sq. in. The reaction chamber is maintained at substantially this same pressure. Heated products are introduced into the lower portion of the reaction chamber wherein no appreciable liquid level is maintained, residual liquid being quickly withdrawn from the reaction zone to the coking zone without substantial loss of heat while vaporous materials are subjected. to continued conversion in the reaction zone, being Withdrawn from the upper portion thereof. An Indiana bituminous coal in the form of fines, having a volatile content of approximately 40 percent, is introduced into the coking zone simultaneous with the introduction of residual oil. The quantity of coal supplied to the system is equivalent to approximately 35 percent by weight of the liquid charging stock supplied to the cracking system. The coking operation is started by the use of incondensable gas from the cracking portion of l the system and this material is augmented as the operation progresses by a portion of the gas from the coking operation. The gas is heated to an average temperature during the coking operation of approximately 1100 F. and is introduced into the coking zone in sufficient quan tity to maintain the coal and oil mixture undergoing treatment at a temperature of approximately 950 F. while even higher temperatures obtain in the bed of coke undergoing devolatilization. A pressure of about 100 pounds per square inch is maintained in the gas heating ele ment and this is reduced in the coking zone to approximately pounds per square inch.

Per unit of charging stock, which comprises a barrel, or about 320 pounds, of fuel oil and about 112 pounds of coal, this operation will yield about 145 pounds of coke having a volatile content of approximately 5 percent, about 28 gallons of distillate of substantially motor fuel boiling range, having an antiknock value equivalent to an octane number of approximately 76. The only other product is gas of high calorific value suitable for carburetion or 'dilution with gas of inferior heating value.

The above example illustrates only one of the many operations possible within the scope of the present invention and is not intended to limit the operating conditions which may be employed nor to define the limits of the results obtainable.

I claim as my invention:

1. In processes of the character wherein hydrocarbon oil is subjected to conversion temperature at super-atmospheric pressure in a heating element and' communicating reaction chamber, the vaporous and non-vaporous products separated, the vapors subjected to fractionation and the resulting light distillate and gas cooled and collected, the non-vaporous residual liquid removed from the reaction chamber and introduced into a coking zone maintained at reduced pressure relative to that em- I ployed in the reaction chamber, vapors from the coking zone subjected to fractionation and the resulting light distillate and gas collected, the improvements which comprise simultaneously introducing coal into the coking zone, subjecting a portion of the gas from the system to an elevated temperature in a separate heating coil and introducing the highly heated gas into the coking zone to effect the production of a low-volatile coke from the residual oil and coal.

2. In a process for the conversion of hydrocarbon oil wherein the oil is subjected to a conversion temperature at super-atmospheric pressure in a heating coil, the heated oil introduced into an enlarged reaction chamber where vaporous and non-vaporous products separate, the vapors subjected to fractionation, their heavy fractionation, re-

/ vapors into light distillate and gas, subjecting a portion of the gas from both the cracking and coking operations to heating in a separate heating coil and introducing the highly heated gas into direct contact with the unvaporized residual material in the coking zone to eifect its devolatilization and reduction to coke.

3. A process for the conversion of hydrocarbon oil and simultaneous coking of the cracked-residue and coal which comprises subjecting the oil to conversion temperature at super-atmospheric pressure in a heating coil and communicating reaction chamber, withdrawing both liquid and vaporous products from the reaction chamber to a reduced pressure coking zone, simultaneously introducing coal into, the coking zone, subjecting vapors from the coking zone to fractionation, returning theirrelatively heavy components, condensed by fractionation, to the heating element for further conversion, separating the vapors remaining uncondensed by ,fractionation into condensed distillate and gas,

4. A process such as defined in claim 1 characterized by the use of a maximum temperature of 850 to 950 F. in the oil heating coil and a maximum temperature of 900 to 1100 F. inthe gas heating coil.

5. A process for producing light oil and coke from heavy hydrocarbon oil and coal, which comprises subjecting the heavy oil to cracking conditions of temperature and superatmospheric pressure in a cracking zone, separating the heated oil into vapors and unvaporized oil, frac tionating and condensing the vapors and separating the condensed portions from the incondensable gases, introducing the unvaporized oil and coal to a coking zone maintained under lower pressure than the cracking zone, heating at least a portion of said gases to an elevated temperature in an independent heating zone, and introducing the highly heated gases into contact with the unvaporized oil and coal in the coking zone to assist the devolatilization and coking of the unvaporized oil and coal therein. 10

CHARLES H. AN GELL.

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