US3600300A - Slurry processing for black oil conversion - Google Patents

Abstract

A CATALYTIC SLURRY PROCESS FOR EFFECTING THE CONVERSION OF A HYDROCARBONACEOUS CHARGE STOCK CONTAINING HYDROCARBON-INSOLUBLE ASPHALTENES. THE SLURRY CONSTITUTES A MIXTURE OF THE MAJOR PROPORTION OF THE CHARGE STOCK, PRINCIPALLY 650*F.-PLUS MATERIAL, A PORTION OF A PREVIOUSLY TREATED PRODUCT EFFLUENT, AND FROM AOBUT 0.4% TO ABOUT 10.0% BY WEIGHT OF FINELY-DIVIDED SOLID CATALYST PARTICLES, ON THE BASIS OF TOTAL LIQUID FEED. THE PROCESS IS EFFECTED IN A CONTINUOUS MANNER, AND PREFERABLY INA N UPFLOW REACTION CHAMBER WHEREIN THE SLURRY AND HYDROGEN ARE INDIVIDUALLY INTRODUCED AT A LOWER PORTION AND THE PRODUCT EFFLUENT WITHDRAWN FROM AN UPPER PORTION.

Description

Allg 17, 1971 L.. R. STEENBERG SLURRY PROCESSING FOR BLACK OIL CONVERSION Filed NOV. 26, 1968 SmAm,

n/ 'V EN mf?.- Laurence Slee/:berg

A TTOF/VEYS United States Patent f 3,000,300 Patented Aug.. l?, 1971 US. Cl. 208-108 8 Claims ABSTRACT OF THE DISCLOSURE A catalytic slurry process for effecting the conversion of a hydrocarbonaceous charge stock containing hydrocarbon-insoluble asphaltenes. The slurry constitutes a mixture of the major proportion of the charge stock, principally 650 F.plus material, a portion of a previously treated product effluent, and from about 0.4% to about 10.0% by Weight of finely-divided solid catalyst particles, on the basis of total liquid feed. The process is effected in a continuous manner, and preferably in an upow reaction chamber wherein the slurry and hydrogen are individually introduced at a lower portion and the product effluent withdrawn from an upper portion.

APPLICABILITY OF INVENTION The process described herein is adaptable to the conversion of petroleum crude oil residuals with high metals content and comprising a hydrocarbon-insoluble asphaltene fraction. More specifically, my invention is directed toward a method for effecting a catalytic slurry process, in the presence of hydrogen, in order to convert atmospheric tower bottoms, vacuum column bottoms, crude oil residuum, topped and/or reduced crude oils, coal oil extracts, crude oils extracted from tar sands, etc., all of which are commonly referred to as black oils.

Petroleum crude oils, and particularly the heavy residuals therefrom, contain sulfurous compounds in exceedingly large quantities, nitrogenous compounds, high molecular weight organo-metallic complexes principally comprising nickel and vanadium as the metallic cornponent, and hydrocarbon-insoluble asphaltic material. The later is generally found to be complexed with sulfur, and to a certain extent, with the metallic contaminants. A black oil is generally characterized in petroleum technology as a heavy hydrocarbonaceous material of which more than about 10.0% (by volume) boils above a temperature of about 105 0 F. (referred to as non-distillables) and which further has a gravity less than about 20.01 API. Sulfur concentrations are exceedingly high, most often greater than 2.0% by weight, Conradson carbon residue factors exceed 1.0% by Weight and the concentration of metals can range from as low as 20 p.p.m. to as high as about 750 p.p.m.

The process encompassed by the present invention is particularly directed toward the conversion of those black oils contaminated by a high metals contenti.e. containing more than about 150 p.p.m. Specic examples of the charge stocks to which the present technique is adaptable, include a vacuum tower bottoms product having a gravity of 7.1 API, and containing 4.1% by Weight of sulfur and 23.7% by weight of heptane-insoluble asphalts; a topped Middle-East crude oil having a gravity of 11.0 API and containing about 10.1% by Weight of asphaltenes and 5.2% by weight of sulfur; and, a vacuum residuum having a gravity of 8.8 API, containing 3.0% by weight of sulfur and 4300 p.p.m. of nitrogen.

The utilization of my invention affords the conversion of such material into distillable hydrocarbons, heretofore having been considered virtually impossible to achieve on a continuous basis with an acceptable catalyst life. The

principal difficulty, heretofore encountered in a xed-bed catalytic system, resides in the lack of sufficient stability in the presence of such relatively large quantities of metalsi.e. from about p.p.m. to as high as 750 p.p.m., computed as the element-and additionally from the presence of large quantities of asphaltic material and other non-distillables. The asphaltic material comprises high molecular weight coke precursors, insoluble in light normally liquid hydrocarbons such as pentane and/or heptane. The asphaltic material is generally found to be dispersed within the black oil, and, when subjected to elevated temperature, has the tendency to `flocculate and polymerize whereby the conversion thereof to more valuable oil-soluble products becomes extremely difficult.

OBI ECTS AND EMBODIMENTS An object of the present invention is to convert nondistillable hydrocarbonaceous material into lower-boiling, distillable hydrocarbons. A corollary objective is to provide a catalytic slurry process for the hydrogenative conversion of a *black oil charge stock.

Another object is to convert a. black oil charge stock into distillable hydrocarbons with minimum yield loss to unconvertible asphaltic residuum-less than about 15.0% by Weight of material boiling .above a temperature of about 1050 F. In many instances, the slurry process, effected as hereafter set forth in greater detail, is effective to the extent that the yield loss to asphaltic residuum is less than about 5.0% by Weight.

In one embodiment, therefore, my invention encompasses a slurry process for effecting the hydrogenative conversion of a black oil charge stock containing nondistillable hydrocarbonaceous material, which process comprises the steps of: (a) introducing said charge stock into a first separation zone, contacting said charge stock therein With a slurry of a finely-divided catalyst and a previously hydrotreated product effluent; (b) withdrawing, at a temperature of at least about 750 F., a rst principally vaporous phase free from non-distillable hydrocarbons and a principally liquid phase slurry containing said catalyst and at least a portion of said charge stock; (c) separating said first principally vaporous phase, at substantially the same pressure and at a lower temperature, to provide a hydrogen-rich second principally vaporous phase and a principally liquid phase containing distillable hydrocarbons; (d) heating said hydrogen-rich vapor phase to a temperature above about 800 F.; (e) introducing the heated hydrogen-rich vapor phase, upflow concurrently with at least a portion of said liquid phase slurry, into a reaction chamber maintained under a pressure greater than about 1,000 p.s.i.g.; and (f) passing the resulting hydrotreated product eflluent/ catalyst slurry into said first separation zone.

In a more specific embodiment, my invention provides a catalytic slurry process for converting a non-distillable hydrocarbon charge stock, in contact with hydrogen, into lower-boiling, distillable hydrocarbon products, which process comprises the steps of: (a) heating a hydrogenrich principally vaporous phase, introducing the heated phase upflow into a reaction chamber, concurrently introducing a slurry of finely-divided catalyst, at least a portion of said charge stock and a hydrotreated hydrocarbon stream, at a temperature in the range of 700 F. to about 800 F.; (b) withdrawing the resulting hydrotreated product efuent/ catalyst slurry from said reaction charnber at a temperature of from about 800 F. to about 900 F.; (c) separating the resulting reaction chamber effluent and said charge stock in a first separation zone, at substantially the same pressure, to provide a first principally vaporous phase and a liquid phase slurry containing said catalyst; (d) introducing at least a major portion of said liquid phase slurry to said reaction chamber as aforesaid; (e) separating said first vaporous phase in a second separation zone, at substantially the same pressure and at a temperature in the range of from about 60 F. to about 140 F., to provide a hydrogenrich second principally vaporous phase and a principally liquid phase comprising distillable hydrocarbons boiling below about l050 F.; and, (f) heating said hydrogenrich vaporous phase to a temperature required to maintain the hydrotreated product efuent/catalyst slurry, withdrawn from said reaction chamber, at a temperature within the aforesaid range, and introducing the heated hydrogen-rich phase into said reaction chamber.

Other embodiments of my invention are directed toward particular operating techniques and preferred ranges of operating variables and conditions. Thus, the volumetric ratio of the hydrocarbonaceous material, introduced into the reaction chamber, to the hydrocarbon charge stock, being introduced into said first separation zone, is within the range of from about 1.5:1 to about l5.0:l. The process is further characterized in that the catalyst concentration, Within the slurry being introduced into the reaction chamber, is in the range of from about 0.4% to about 10.0% by weight. A preferred technique, with respect to fresh catalyst employed as make-up, or that recovered from the unconverted asphaltic residuum, involves introducing such catalyst into the first separation zone as a slurry with the fresh charge stock.

SUMMARY OF INVENTION The particular, finely-divided, solid catalyst utilized in the present slurry process, is not considered to be essential. However, it must be recognized that the catalytically active metallic component of the catalyst necessarily possesses both cracking and hydrogenation activity. Thus, in most applications of the present invention, the catalytically active metallic component will be selected from the metals of Groups V-B, VI-B and VIII of the Periodic Table. Of these, preferred metallic components are vanadium, chromium, iron, cobalt, nickel, niobium, molybdenum, tantalum and/or tungsten; the noble metals of Group VIII are not generally considered for use in a slurry-type process, particularly in view of economic considerations. Recent investigations and developments in catalytic slurry processing of heavy hydrocarbon charge stocks have indicated that the sulfides of the foregoing metals, and particularly those of Group V-B, offer more advantageous results. For this reason, the preferred unsupported catalyst comprises ltantalum, niobium and vanadium sulfides, the latter being particularly preferred. In the interest of brevity, the following discussion will be limited to the use of vanadium sulfides as the catalyst employed in l the present slurry process.

The vanadium sulfides may be prepared in any convenient manner, the precise method not being essential to the present invention. For example, vanadium pentoxide may be reduced with sulfur dioxide and water to yield a solid hydrate of vanadyl sulfate. The latter is treated with hydrogen sulfide at a temperature of about 300 C. to form vanadium tetrasulfide. Reducing the vanadium tetrasulfide in hydrogen at a temperature above about 300 C. produces the vanadium sulfide slurried into the system.

The concentration of vanadium sulfides slurried with the hydrocarbonaceous material charged to the reaction chamber, is within the range of from about 0.4% to about 10.0% by weight, calculated as the elemental metal. Excessive concentrations do not appear to enhance the results, even with extremely contaminated charge stocks having exceedingly high asphaltene concentrations. Preferred concentrations of vanadium sulfides are within the range of from about 2.0% to about 6.0% by weight. It should be noted that vanadium forms a multiplicity of sulfides, some of which are non-stoichiometric. Examples of various sulfides of vanadium include VS, VS2, V2S3, V54, VS3 and V255. During the reactions,

the vanadium sulfide prepared as hereinabove set forth, is converted to one or more of these forms, or some other form.

Following suitable heat-exchange 'with various hot effluent streams, the fresh hydrocarbon charge stock is introduced into an elongated separation zone at a temperature in the range of about 350 F. to about 650 F., and preferably from about 400 F.-600 F. The hydrotreated product efliuent/catalyst slurry, emanating from the reaction chamber at a temperature in the range of about 800 F. to about 900 F. is also introduced into the contactor/separator zone. The contactor/ separator essentially serves a two-fold purpose. The charge stock contacts the hot hydrotreated product effluent causing at least a portion of the lighter components of the charge stock to vaporize and be removed overhead in the principally vaporous phase. The hydrotreated product eiuent/ catalyst slurry is quenched to a degree such that catalytic action ceases while the heavy portion fof both the charge stock and product efiiuent, including the finely-divided vanadium sulfide particles, settle to the bottom of the elongated separation zone. The precise temperature, to which the fresh charge stock is heated, is such that the condensed liquid phase slurry in the bottom of the contactor/ separator is at a temperature of from 700 F. to about 800 F. The vaporous phase Withdrawn as an overhead product from the separation zone, including the lighter components of the fresh charge stock as hereinbefore stated, is at a temperature of about 750 F. to about 850 F., and consists primarily of hydrogen, hydrogen sulfide, ammonia, normally gaseous hydrocarbons and distillable hydrocarbons boiling below a temperature of about 980 F. Since itis more important to prevent vanadium sulfide catalyst particles from carrying over with the overhead vapor phase, than to effect a clean separation, the principally vaporous phase from the separation zone will contain a minor quantity of normally liquid hydrocarbons boiling in the range of 980 F. to 1050 F.

The principally liquid phase Withdrawn from the bottom of the contacter/separator, at a temperature of from 700 F. to about 800 F., is essentially free from distillable hydrocarbons boiling below a temperature of 650 F. With respect to this bottom stream, while it may be introduced en toto into the reaction chamber, a preferred operating technique involves with drawing a drag stream containing at least about 10.0% by weight of the catalyst employed. Any suitable means may be utilized to separate the solid catalyst from the liquid phase hydrocarbons, including filtration, settling tanks, a series of centrifuges, etc. A like quantity of fresh, or regenerated catalyst is then added to the fresh hydrocarbon charge stock entering the contactor/separator in order to maintain the de- Sired catalyst content of the slurry being withdrawn as the bottom stream. Although the quantity of the drag stream, Withdrawn from the contacter/separator, is such that at least 10.0% by weight of the catalyst, as vanadium, is removed, the precise amount in any given situation is primarily dependent upon the concentration of metal contaminants in the feed and the depth of the separation effected, the latter determining the quantity of hydrocarbons in the bottom of the contactor/separator.

The catalyst may be recovered, or separated by, a series of filtration and methylnaphthalene washing techniques. The methylnaphthalene is employed to remove residual, soluble hydrocarbons from the catalyst sludge. Other suitable solvents include benzene, toluene, etc. The remainder of the sludge is burned in air, resulting in vanadium pentoxide which is subsequently reduced with sulfur dioxide and water to produce vanadyl sulfate. The procedure then follows the previously described scheme for the preparation ofthe fresh vanadium sulfide. The bottom stream from the contactor/separator, at a temperature in the range of from about 700 F. to about 800 F., is introduced into the lower portion of an elongated reaction vessel, in order to provide upward flow therethrough. Heated hydrogen, at a temperature in the range of from about 800 F. to about 900 F., in an amount of from about 5,000 to about 150,000 standard cubic feet per barrel of normally liquid hydrocarbon feed, is also introduced into a lower portion of the reaction chamber. In order to enhance intimate contact between the catalyst particles, the hydrocarbon molecules and the hydrogen, a preferred technique involves separately introducing the heated hydrogen and liquid phase slurry streams into the bottom of the reaction chamber. The particular design and/ or configuration of the mechanical devices selected to insure intimate contacting of the reactants, is not essential to my invention. Such devices, including spray nozzles, concentric bayonets, etc., are well known and clearly described in the art pertaining thereto. Residence time, within the reaction chamber, depends upon a multitude of considerations. Not the least of these considerations involves temperature, the degree of mixing, the catalyst concentration, charge stock characteristics, the degree of conversion, and the volumetric ratio of recycle material to fresh feed. The residence time will, in most applications of my invention, range from about 30 seconds to about four minutes. For a given charge stock, residence time will involve the temperature and the feed properties.

The reaction chamber is maintained at a pressure within the range of from about 1,000 to about 4,000 p.s.i.g., and preferably at an intermediate level of from 1500 to about 3500 p.s.i.g. An essential feature of my invention resides in the control of the top temperature of the reaction chamber, or the temperature of the hydrotreated product etiiuent/catalyst slurry being removed therefrom. The temperature is controlled within the range of from about 800 F. to about 900 F., and perferably from about 825 F. to about 875 F. The temperature is controlled at a predetermined level by monitoring the degree to which the circulating hydrogen stream is heated. Although a temperature prole within the reaction chamber indicates essentially iso-thermal conditions, it must be recognized that the principal reactions being efected are exothermic, and a small temperature diiferential will in fact exist within the reaction chamber.

As hereinbefore set forth, the reaction chamber effluent, as a slurry with the finely-divided catalyst particles, is introduced into the contactor/separator at substantially the same pressure and temperature. The principally vaporous phase from the contactor/separator is condensed at a temperature in the range of from about 60 F. to about 140 F., and introduced into a cold separator at substantially the same pressure. A hydrogen-rich gaseous phase is removed therefrom, and recycled to the bottom of the reaction chamber after being heated to the desired degree. Make-up hydrogen, generally in amounts of from about 1,000 to about 2,000 standard cubic feet per barrel, may be introduced to the system at any convenient point. However, the make-up hydrogen is generally introduced upstream from compressive means utilized to circulate the hydrogen at the elevated pressure. The principally liquid phase from the cold separator, constituting a portion of the product of the present process, is subjected to one or more fractionation/ distillation procedures in order to provide the desired component fractions. Another portion of the overall product of the present slurry process constitutes the distillable material recoverable from the catalyst sludge withdrawn as the drag stream from the contactor/ separator.

DESCRIPTION OF DRAWING For the purpose of demonstrating the illustrated embodiment, and the utilization therein of the process of the present invention, the drawing will be described in connection with the conversion of a Canadian crude oil which has been topped to remove normally liquid hydrocarbonaceous material principally boiling below a temperature of 650 F. The as-received crude oil has a gravity of 11.1 API, and contains about 4.35% by weight of sulfur. On the basis of a commercially-scaled unit having a design capacity of about 100,000 barrels per day, the 650 F.minus normally liquid hydrocarbons comprises about 1,150 barrels per day of 300 F. (end point) gasoline, 4,600 barrels per day of a kerosene fraction boiling from 300 F. to 450 F. and 15,200 barrels per day of a gas oil fraction boiling from 450 F. to 650 F.

With respect to the 79,050 barrels per day of 650 F.- plus material, the gravity is 6.7 API, and the sulfur concentration is 5.0% by Weight; the topped crude contains about 4500 parts per million of nitrogen, has a Conradson carbon residue factor of 17.0% by Weight, contains about 10.0% by Weight of heptane-insoluble material, about 289 ppm. of metals and has a viscosity, cst./ 122 F., of 40,700. In the drawing, the embodiment is presented by means of a simplified ow diagram in which such details as pumps, instrumentation and controls, heat-exchange and heat-recovery circuits, valving, start-up lines and similar hardware have been omitted; these are considered non-essential to an understanding of the techniques involved. The use of such miscellaneous appurtenances, to modify the illustrated process How, are well within the purview of those skilled in the art. Similarly, it is understood that the charge stock, stream compositions, operating conditions, catalyst, design of fractionators, separators and the like are exemplary only, and may be varied widely without the departure from the spirit of my invention, the scope of which is dened by the appended claims.

It is intended that the charge stock be converted into maximum distillable hydrocarbons which are recoverable through the use of ordinary distillation techniques in commonly utilized fractionation systems. They component yields, as hereinafter set forth, are based upon a charge rate of 79,050 barrels per day of 650 F.plus material.

With reference now to the drawing, circulating hydrogen in an amount of 10,000 standard cubic feet per barrel, based upon the 79,050 barrels per day of the topped crude charge, in line 1, is introduced into heater 2. Although not illustrated in the drawing, the circulating hydrogen stream is subjected to conventional heat-exchange techniques with various hot effluent streams in order to decrease the load upon heater 2. The heated hydrogen stream at a temperature of about 875 F., is introduced via line 3 into reaction chamber 4 through a locus in the lower portion thereof. Reactor 4 is at a pressure of about 3100 p.s.i.g., and the controlled, predetermined top temperature is about 840 F. Also introduced into the lower portion of reactor 4, is a slurry of a portion of the charge stock, primarily 650 F.plus, a portion of a previously hydrotreated product ei'liuent and a vanadium suliide catalyst, finely divided in a size ranging from 0.5 to 10.0 microns. The catalyst concentration in the slurry, calculated as vanadium, is about 3.0% by weight. It should be noted that, although the heated hydrogen and slurry are concurrently processed upow, the slurry is introduced into the reaction chamber through a locus separate from that of the heated hydrogen. As illustrated in the drawing, reactor 4 is equipped with side-to-side pans. It is, however, understood that the use of such mechanical devices, or none at all, is easily determined by one having skill in the art.

The total hydrotreated product effluent, as a slurry with the vanadium sulfide catalyst, is withdrawn from reactor 4 by way of line 6, and introduced therethrough, at substantially the same temperature and a pressure of about 3,020 p.s.i.g., into contactor separator 7. In order to bring the liquid phase and catalyst portion of the product efliuent to a temperature level below reaction temperature, fresh hydrocarbon charge stock is introduced into contactor separator 7 by way of line 12 at a temperature of about 440 F. The function of the contactor/separator is essentially two-fold: (l) to permit all material vaporized at about 840 F., to remain vaporous for introduction into cold separator 10; and (2) to cool the liquid in equilibrium therewith at about 840 F., to a lower temperature. This is accomplished by introducing the fresh charge, by way of line 12, at a lower temperature in the range of 350 F. to 650 F.

The liquid phase, catalyst slurry in the bottom of contactor separator 7, at a temperature of about 775 F., is removed therefrom by way of line 8. A portion of this liquid phase slurry, in an amount of 237,150 barrels per day, is diverted by way of line into the lower portion of reaction chamber 4. The remainder of the liquid phase slurry is removed from the process by way of line 8, to a solids and distillate recovery system as hereinbefore set forth.

The principally vaporous phase from contactor/separator 7 is withdrawn by way of line 9 and introduced therethrough into cold separator 10, following condensation and cooling at a temperature of about 100 F. Cold separator 10, is maintained under a pressure of 3,000 p.s.i.g., and serves as the focal point for pressure control throughout the system. Thus, the pressure on reaction chamber 4 and contactor/iseparator 7 will be somewhat greater in order to compensate for the pressure drop experienced as a result of fluid flow through the system. The principally hydrogen-rich vaporous phase from cold separator 10 is recycled through line 1, along with makeup hydrogen from line 13 in an amount of about 1300 standard cubic feet per barrel, to be heated to a temperature of about 875 F. in heater 2. A normally liquid hydrocarbon-containing phase is withdrawn from cold separator 10 by way of line 11, and introduced therethrough into a suitable fractionation system.

Component analyses, indicating the overall product yield and distribution are' presented in the following table:

TABLE- PRODUCT YIELD AND DISTRIBUTION Weight Volume Component percent l percent 1 Ammonia 0. 2 Hydrogen sulfide 2. 1 Methane 0. 9 Ethane 0.9 Propane 1. 3 Butanes/butenes. l. 3 Pentanes/pentene 1.0 Hexanes/hexenes- 1. 8

1 Reflects a hydrogen consumption ol 1,320 s.c.f./bbl., or 1.9% by weight of fresh feed.

The foregoing specification, and particularly the eX- ample integrated into the description of the drawing, clearly illustrates t-he process of the present invention and the benefits afforded through the utilization thereof.

Among the many advantages of the present slurry process is excellent temperature control without the need of a fired heater for fresh feed, or for any catalyst-containing hydrocarbon stream. Significantly facilitated shutdown maintenance is also afforded. It should further be noted that catalyst traffic is minimized at less than reaction chamber pressure.

I claim as my invention:

1. A slurry process for the hydrogenative conversion of a black oil charge stock containing non-distillable hydrocarbonaceous material, whichprocess comprises the steps of:

(a) introducing said charge stock at a temperature of about 350 F. to about 650 F. into a first separation zone, therein contacting said charge stock with a hot slurry of finely-divided catalyst and a previously hydrotreated product effluent obtained as hereinafter specified, thereby quenching said product effluent/ catalyst slurry to a degree such that catalytic action substantially ceases while vaporizing a portion of said charge stock;

(b) withdrawing from said first separation zone, at a temperature of at least about 750 F., a first principally vaporous phase, free from non-distillable hydrocarbons, and a first principally liquid phase slurry containing said catalyst and at least a portion of said charge stock;

(c) separating said first principally vaporous phase, at

substantially the same pressure and a lower temperature, to provide a hydrogen-rich second principally vaporous phase and a second principally liquid phase containing distillable hydrocarbons;

(d) heating said hydrogen-rich vapor phase to a temperautre above about 800 F.;

(e) introducing the heated hydrogen-rich vapor phase, and upfiow concurrently with at least a portion of said liquid phase slurry, into a reaction chamber at a pressure greater than 1,000 p.s.i.g., and,

(f) passing the resulting total hydro-treated product efiiuent/catalyst slurry, -at a temperature of about 800 F. to about 900 F., from said reaction chamber into said first separation zone to provide said hot slurry as aforesaid.

2. The process of claim 1 further characterized in that said reaction chamber is maintained at a pressure in the range of from about 1,000 to about 4,000 p.s.i.g.

3. The process of claim 1 further characterized in that said first principally vaporous phase is withdrawn from said first separation zone at a temperature of from about 750 F. to about 850 F.

4. The process of claim 1 further characterized in that the volumetric ratio of the hydrocarbons in said liquid phase slurry, introduced into said reaction chamber, to said charge stock is at least about 1.5: 1.

5. A catalytic slurry process for converting a non-distillable hydrocarbon charge stock, in contact with hydrogen, into lower-boiling, distillable hydrocarbon products, which process comprises the steps of:

(a) heating a hydrogen-rich principally vaporous phase, introducing the heated phase upow into a reaction chamber, concurrently introducing thereto a first liquid phase slurry of finely-divided catalyst obtained as hereinafter specified at a temperature in the range of 700 F. to about 800 F.;

(b) withdrawing the resulting hydrotreated product effluent/catalyst slurry from said reaction chamber at a temperature of from about `800 F. to 900 F.;

(c) introducing the resulting total reaction chamber efiiuent, at substantially reaction chamber temperature, and said charge stock, at a temperature of about 350 F. to about `650 F. into a first separation zone, therein contacting said efiiuent with said charge stock and quenching the efliuent to a degree suc-h that catalytic action substantially ceases while Vaporizing a portion of said charge stock, and separating the contents of said first separation zone at substantially the same pressure to provide a first principally vaporous phase and a first liquid phase slurry containing said catalyst;

(d) introducing at least the major portion of said first liquid phase slurry to said reaction chamber as aforesaid;

(e) separating said first vaporous phase in a second separation zone, at substantially the same pressure and at a temperature in the range of 60 F. to about F., to provide a hydrogen-rich second principally vaporous phase and a principally liquid phase cornprising distillable hydrocarbons boiling below about l050 F.; and,

(f) heating said hydrogen-rich vaporous phase to a temperature required to maintain the hydrotreated product efliuent/ catalyst slurry, withdrawn from said reaction chamber, at a temperature within the aforesaid range, and introducing the heated hydrogen-rich at least a portion of said finely-divided catalyst is introphase into said reaction chamber. duced into said first separation zone `as a slurry with said 6. The process of claim 5 further characterized in that charge stock.

the volumetric ratio of the hydrocarbonaceous material, References Cited introduced into said reaction chamberE to the hydroclar- 5 UNITED STATES PATENTS bon char-ge stock, mtroduced mto said first separation flabclll weerign e range o rom about 0 4% 10 DELBERT E. GANTL Pnmary Exammer 8. The process of claim 5 further characterized in that R. M. BRUSKIN, Assistant Examiner

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