US2885342A

US2885342A - Fluidized solids refluxing in hydrocarbon conversions

Info

Publication number: US2885342A
Application number: US348460A
Authority: US
Inventors: Percival C Keith
Original assignee: Hydrocarbon Research Inc
Current assignee: Hydrocarbon Research Inc
Priority date: 1953-04-13
Filing date: 1953-04-13
Publication date: 1959-05-05
Anticipated expiration: 1976-05-05

Description

United States Patent FLUIDIZED SOLIDS REFLUXING IN HYDROCARBON CONVERSIONS Percival C. Keith, Peapack, N.J., assignor to Hydrocarbon }lesearch, Inc., New York, N.Y., a corporation of New ersey Application April 13, 1953, Serial No. 348,460

13 Claims. (Cl. 208-59) This invention relates to the high-temperature conversion of hydrocarbon oils and is more particularly concerned with a process for converting" hydrocarbon oils boiling above the gasoline range into lower boiling hydrocarbons, particularly gasoline hydrocarbons. The class of hydrocarbon conversions contemplated by the present invention involves the cyclic flow of comminuted solid material maintained in a fluidized state through a hydrocarbon conversion zone in contact with the hydrocarbon oil and through a regeneration zone wherein carbonaceous matter deposited on the solid material while in the conversion zone is removed from the solid material by reaction with an oxygen-containing regenerating gas. An important aspect of the present invention is the control of the conversion reactions to effect maximum conversion into gasoline-range hydrocarbons.

In modern petroleum refining practice, it is highly advantageous to convert as much as possible of the higher boiling portions of a petroleum crude oil to materials boiling in the gasoline range. For this purpose there have been proposed processes which involve the cracking of the higher boiling hydrocarbons into hydrocarbons of lower boiling points. These proposed proceses, however, do not provide the degree of conversion desired and simultaneously produce a large quantity of non-gasoline products which have to be separated from the gasoline fraction by special treatment and represent less valuable by-products of these processes. Furthermore, these processes, which are effective in the treatment of the ordinary type of petroleum crude oil, are of relatively little eifectiveness in producing gasoline of commercially acceptable quality from heavy hydrocarbon oils, particularly those which have a high content of sulfur compounds, nitrogen compounds, metal compounds and inorganic salts, such as low grade crudes, petroleum residues, shale oil, and the like. A process which involves so-called delayed coking has been proposed and, in fact, has been utilized to some extent for processing heavy residues, serving in eifect as a process for preparing a feed stock for subsequent conventional catalytic cracking. However, this processing scheme for heavy residues has several disadvantages. Primarily, the delayed coker is expensive with respect to capital and operating costs. The yield of hydrocarbons in the gasoline range is low, and this gasoline is relatively poor in octane rating, so that when it is added to the total pooled refinery gasoline, overall octane number is descreased significantly. Further, delayed coking does not effect adequate desulfurization of the charge and, as a result, the, coker distillate, which is used as feed for the catalytic cracker, is of excessively high sulfur content, resulting in inefficient and expensive operation of the cracker. In many cases, a finished gasoline product of commercially acceptable sulfur content cannot be prepared at all. In addition, a large proportion of the charge is converted solely to low value coke, which is difficult to market and is an undesired lay-product.

Propane deasphalting has likewise been used as a means jot: the preliminarytreatment, of crude oil to providea feed for a subsequent catalytic cracking operation. This processing scheme offers very few advantages over the delayed coking-catalytic cracking scheme referred to above, and is completely unsatisfactory for processing total or reduced crudes of high sulfur content.

Since heavy crude oils of the type mentioned are formmg an ever greater proportion of the total crudes available for gasoline production, the satisfactory processing. of this type of crude, and particularly the processing of such crudes to produce high octane gasoline, especially without the concurrent formation of large quantities of undesired by-products, are technical and economic problerns of increasing importance.

Not only is it desired to produce a large proportion of gasoline but it is also advantageous to do so with minimum production of low value by-products, such as coke, which require removal from the oil-treating system and separate disposal.

It is, therefore, a principal object of the present invention to provide a process for treating hydrocarbon oils to produce therefrom a high proportion of gasoline.

It is a further object of the present invention to provide a high-temperature treating process by means of which substantial proportions of gasoline of high octane number are produced even from heavy hydrocarbon oils.

It is a still further object of the invention to provide a process of producing gasoline from heavy crude oils which may be carried out continuously and efliciently with high conversion of the charge stock to high octane gasoline and valuable gasiform products and a corresponding low conversion to carbonaceous residues and heavy liquid products.

In accordance with the invention, hydrocarbon oil is subjected to treatment at elevated temperature in a reaction zone in the presence of a particulate contact material or carrier and in a gaseous atmosphere which is provided by passing into the reaction zone at least a portion of the gaseous eflluent from a regeneration zone in which coke formed on the carrier by the oil undergoing treatment is converted with oxygen and steam to a hydrogen-rich gas. The hydrocarbon oil is fed at an elevated temperature into the reaction zone (hereinafter designated as the primary conversion zone) and the contaminated carrier flows from the primary conversion zone into a secondary conversion zone wherein it intermingles with regeneration product gases coming from the regeneration zone. The carrier in the secondary conversion zone is maintained at a temperature intermediate the temperatures of the primary conversion and regeneration zones and from the secondary conversion zone is passed to the regeneration zone. The hydrocarbon oil introduced into the primary conversion zone is converted to vaporized products and a hydrocarbonaceous residue deposited on the carrier particles. In the secondary conversion zone the hydrocarbonaceous residue is further converted into more vaporized products which flow into the primary conversion zone and a dry carbonaceous residue or coke that is gasified in the regeneration zone.

In accordance with a characteristic feature of the invention, the hydrocarbon vapors from the primary conversion zone fiow to a reflux zone containing the particulate car'- rier in a dense-phase fluidized state and maintained at a controlled temperature lower than the temperature in the primary conversion zone. The lower temperature in the flux zone causes condensation of some of the vapors on .the carrier in that zone and carrier with condensed vapors is recycled to the primary conversion zone. To complete the above described cycle in accordance with the inven tion, regenerated carrier is transferred from the regeneration zone into one or more of the other zones, and regen eration product gases flow from the regeneration zone through. all of the other zones. In. one embodiment of .bOiling' point.

-volume of the primary conversion zone.

the invention, the freshlyregenerated carrier is transferred directly to the reflux zone from which it moves downwardly into the lower zones. In another embodiment, vthe freshly regenerated carrier is transferred to the sec- .ondary conversion zone and from this zone is transferred stepwise to the superposed zones. In a further embodiment of the invention, the freshly regenerated carrier is directly transferred both to the reflux zone and to a conversion zone.

The reflux zone may be provided with any convenient means for temperature control, e.g., cooling coils. The extent of condensation in the reflux zone can be controlled ,so that the vaporous product withdrawn from the reflux zone will have essentially any desired end Substantially the entire vaporous effluent from the reflux zone can be controlled to boil below the 400 F. end boiling point of the gasoline range or,

advantageously, at a somewhat higher temperature to include in the vaporous effluent the valuable hydrocarbons boiling in the distillate heating oil range, which extends generally from 400 F. to above 700 F. However, in no case do the heavier hydrocarbons from the feed stock form a substantial part of the vaporous efiluent and these undesired and valueless hydrocarbons are continuously subjected to repeated treatment to effect maximum conversion to the above-mentioned valuable hydrocarbon products.

In the regeneration zone, the non-volatile carbonaceous deposit on the particulate carrier is desirably consumed by reaction with a regenerating .gas consisting essentially of steam and oxygen, at a temperature of at least 1600 F. and generally below 2500 F. Thus, the regeneration of the carrier results in the production of a gaseous mixture comprising principally carbon dioxide, carbon monoxide and hydrogen together with excess steam. The regenerating gas contains a preponderance of steam and .a minor proportion of high-purity oxygen, the latter more specifically containing at least 90% by volume of oxygen, preferably at least 95% by volume of oxygen, and obtained, for example, by air liquefaction and rectification. Steam-to-oxygen volume ratios in the range of 1.5:1 to 5:1 are generally satisfactory for generating hydrogen.

The effluent gaseous mixture from the regeneration zone is passed through the conversion and reflux zones and serves both as the atmosphere for the hydrocarbon conversion reactions and as the principal medium for .carrier fluidization in these zones.

The entire reaction system. i.e., the primary conversion zone, the secondary conversion zone, the reflux zone and the regeneration zone, is maintained at a total pressure ,of 150 to 800 p.s.i.g. (pounds per square inch gauge),

.allows efficient recovery of the normally liquid product hydrocarbons from the effluent from the reflux zone.

The temperature of the primary conversion zone is maintained in the range of 850 to 1100 F., preferably in the range of 900 to 1050 F. The feed rate of hydrocarbon oil is generally maintained at 0.2 to 3.0 volumes, preferably 0.5 to 1.5 volumes, of liquid oil per hour per The oil partial pressure, determined essentially by the rate of hydrocarbon oil feed, the volume of regeneration product gases :and the total pressure may vary from 5 to'lOO p.s.i.,

preferably from to 50 p.s.i. The preferred range of conversion temperature is higher and the preferred range of oil partial pressure lower than are generally employed in thermal cracking processes and, as a consequence, lthesgasoline which is produced is considerably higher in 4 octane number than that produced in such Processes, approximating CFRR octane number wtihout use of tetraethyl lead or other anti-knock additives.

The temperature in the secondary conversion zone, if employed, is intermediate those in the primary conversion zone and in the regeneration zone and preferably varies progressively from the lower temperature to the higher. Under these conditions, heavy hydrocarbons ab sorbed on spent carrier particles are readily cracked and volatilized within the secondary conversion zone, with the result that recovery of volatile products from the absorbed hydrocarbons entering the secondary conversion zone is made possible and at the same time the gasification load on the regeneration zone is decreased.

The reflux zone is maintained at .a temperature at which substantially no cracking or conversion of hydrocarbons occurs. The reflux zone is thus maintained at .a temperaure below 800 .F. and preferably in the range ,ing above the gasoline range and to obtain a liquid product boiling substantially in the gasoline range, the temperature in the reflux zone may be on the order of 400 F.

It is highly desirable to preheat all of the reactants entering the reaction system to temperatures approaching the respective reaction temperatures of these reactants. For instance, when the regeneration zone is operated at temperatures of not less than about 1600 F., steam and oxygen required for regeneration are charged at about 1000 F. and 400 F., respectively. With the conversion zone operating at temperatures of not less than about 850 F., it is advisable to preheat the hydrocarbon stream to a temperature as close to the conversion temperature as is possbile without causing coking or other hydrocarbon degradation in the preheater. Most hydrocarbon feed stocks can be safely preheated to temperatures of about 800 F.

The particulate carrier which is employed in the process of the invention is any solid, heat-resistant material which may be fluidized, such as sand, quartz, alumina, magnesia, zircon, beryl, bauxite or other like material, which will withstand temperatures up to 2500" F. without degradation or other adverse effect. The particle size of the carrier may vary over a wide range but for best results averages from 40 to 200 mesh, and is preferably in a range of 20 to below 325 mesh, with 90% by weight of the particles between 40 and 200 mesh.

From the reflux zone there is obtained a gasiform'effluent which is passed to a condenser to separate the gasoline range hydrocarbons from gaseous products, including hydrogen, carbon oxides, nitrogen and normally gaseous hydrocarbons, such as methane. When the reflux zone is operated at temperatures approaching 800 F.,

the effluent condensate will contain some hydrocarbons boiling above the gasoline range. These are readily separated from the gasoline by fractional distillation.

The term gasoline fraction as used herein has its conventional meaning, viz., a hydrocarbon fraction boiling within the temperature range of 90 to 400 F.

In most cases the gasoline produced by the foregoing process has a sulfur content within commercially desirable limits and is in other respects an acceptable product. In those cases where, because of the excessively poor quality of the oil treated, the gasoline produced, although of much reduced sulfur content, still contains more sulfur than is desirable or has less than the desired stability characteristics, the sulfur content and the stability characteristics can be brought to more desirable values by catalytic treatment at elevated temperatures. For example, the gasoline-treating processes described in the copending applications of Clarence A. Johnson and Seymour C. Schuman, Serial Nos. 272,511 and 272,512, filed February 19, 1952, now U.S. Patent Nos. 2,707,698 and 2,774,718 and of Percival C. Keith, Serial No.

aasaaaa 272,495, filed February 19, 1952, now U.S. Patent No. 2,707,700, may be used.

For a fuller understanding of the invention, reference is made to the accompanying drawings wherein,

Figure 1 is a sectional elevation of an apparatus suitable for carrying out the above-described process; and

Figure 2 is a similar view of a modified form of apparatus.

Referring to Fig. 1, the apparatus illustrated comprises an upright cylindrical vessel in which are provided four processing zones. At the bottom of vessel 10 is regeneration zone 12 which is separated from a superposed secondary conversion zone 14 by a perforated plate or grid 15. Secondary conversion zone 14 is filled with packing bodies, for example, 2" ceramic Raschig rings, to provide a zone of restricted flow wherein top-to-bottom mixing of the particulate carrier does not occur to any appreciable extent. A primary conversion zone 16 is disposed above secondary conversion zone 14 and is separated from a superposed reflux zone 18 by a perforated plate 20. Baffle plates or other form of grid may be used in lieu of perforated plate 20. To transport the densephase fluidized carrier which fills the reactor to the pseudo-liquid level 22, there are provided an axial transport tube 24 extending upwardly from the lower portion of regeneration zone 12 to primary conversion zone '16 and a second transport tube 26 extending from regeneration zone 12 directly to reflux zone 18. Tubes 24 and 26 are provided with

inlet ports

28 and 29, respectively, for receiving carrier from regeneration zone 12, these inlet ports being controlled by

adjustable valves

30 and 31, respectively, which are mounted on

pipes

33 and 34, respectively, and which are vertically movable relative to

ports

28 and 29. Steam or recycle gas enters

pipes

33 and 34 to lift the carrier from regeneration zone 12 by maintaining the superficial gas velocity in tubes 24 and 26 higher than in other parts of the system.

In accordance with a feature of the invention, a cooling coil 36 is positioned in reflux zone 18 for controlling the temperature of the materials in this zone. The oil to be treated is supplied through an inlet 38, suitably provided with distribution nozzles 40 and, in the embodiment illustrated, inlet 38 is connected to cooling coil 36 so that the feed stock acts as the cooling medium in the reflux zone. Steam and oxygen for regeneration are admitted through an inlet pipe 41 in regeneration zone 12 and the gasiform products of reaction of the system are removed through an outlet 42, suitably provided with a cyclone separator 44 to separate any particles of carrier which are entrained in the gaseous effluent.

As will be apparent from inspection of Fig. 1, the carrier circulates downward from reflux zone 18 to primary conversion zone 16, then through secondary conversion zone 14 into regeneration zone 12. After regeneration, the carrier is transported upward into primary conversion zone through tube 28 and into reflux zone through tube 29, the desired circulation rates in the respective transport tubes being controlled by the use of

valves

30 and 31.

In Fig. 2 is shown an apparatus arranged for somewhat modified flow of materials wherein a reaction vessel 50 contains a regeneration zone 52 separated from a secondary conversion zone 54 by a foraminous member .or perforated plate 56. Zone 54 is separated from a primary conversion zone 58 by perforated plate 60 and an uppermost reflux zone 62 is separated from conversion zone 58 by perforated plate 64. A mass of dense-phase fluidized catalyst or carrier with an upper pseudo-liquid level 65 fills the four zones in vessel 50. The regenerating gases enter regeneration zone 52 through inlet 66 and the resulting regeneration product gases, with entrained regenerated carrier particles, flow through the constricted openings in plate 56 with substantially no back-flow of carrier through these openings. The hot regeneration product gases and. particles of regenerated carrier intermingle in secondary conversion zone 54 with spent 01' fouled carrier particles discharging from primary conversion zone 58 through a return duct 68. Under the influence of the higher temperature in secondary conversion zone 54 and the regeneration product gases, adsorbed hydrocarbons are converted and removed from spent carrier particles and conveyed with the regeneration product gases through perforated plate 60 into primary conversion zone 58. The admixture of regenerated carrier particles and spent carrier particles, now substantially free of adsorbed hydrocarbons, is partly carried up into primary conversion zone 58 by the gases passing through perforated plate 60 and partly recycled to regeneration zone 52 through return duct 70. The oil to be treated enters primary conversion zone 58 through pipe 72 provided with a plurality of nozzles 74. Conversion products and accompanying regeneration product gases carry fluidized carrier particles up through perforated plate 64 into reflux zone 62 which is at a temperature controlled by the flow of a suitable cooling medium through cooling coil 75. The gaseous effluent containing all of the gases and vapors in vessel 50 becomes separated from the densephase fluidized carrier mass in the region of its pseudofluid level 65 and leaves vessel 50 through pipe 80. The gaseous effluent is purged of any entrained particles in cyclone separator 82 when it flows by way of pipe 84- to a separation plant (not shown) for the recovery of desired product fractions. Carrier particles removed from the gaseous effluent in separator 82 are returned to reflux zone 62 through standpipe 85 and carrier particles flow from reflux zone 62 into primary conversion zone 58 through return duct 86.

As in the previously described embodiment, secondary conversion zone 54 is maintained at a temperature intermediate the temperatures in regeneration zone 52 and primary conversion zone 58 but by somewhat different means. In the embodiment of Fig. 2, the carrier in secondary conversion zone 54 is circulated from this zone to each of the adjacent two zones and from those zones back to the secondary conversion zone. Specifically, carrier flows from regeneration zone 52 up through perforated plate or grid 56 into secondary conversion zone 54 and thence through duct 70 back to regeneration zone 52. At the same time, carrier from secondary conversion zone 54 flows upwardly through grid 60 into primary conversion zone 58 and thence downwardly through duct 68 into zone 54. Meanwhile carrier particles circulate upwardly into reflux zone 62 through plate 64 and return through duct 86.

Ducts

68, 70 and 86 are provided, respectively, with adjustable closure means 87, 88 and 89 at their lower extremities to regulate independently the rates of carrier circulation between primary conversion zone 58 and secondary conversion zone 54, between secondary conversion zone 54 and regeneration zone 52, and between reflux zone 62 and primary conversion zone 58.

Tubes

92, 93 and 94 are used to inject a fluidizing medium like steam into the lower portions of

ducts

68, 70 and 86, respectively, in order to prevent the stoppage of carrier within these ducts.

The following specific example is further illustrative of the process of this invention and is described with particular reference to the apparatus of Fig. 1.

Vessel 10 is charged with bauxite of 20 to 325 mesh size with by weight of the particles between 40 and 200 mesh. Steam preheated to 1000 F. is introduced through

lines

33 and 34. A mixture of 60 volumes of steam and 40 volumes of oxygen of at least 95% by volume purity is introduced through inlet 41. The charge stock oil is preheated to 720 F. by passage through coil 36 in reflux zone 18, and is then additionally preheated to 875 F. in a tube furnace (not shown) before entering vessel 10 through inlet 38 and nozzles 40. The oil is fed at a rate of 5000 barrels per day; it is a low-grade total crude from the Boscan field of Venezuela, having 7 10.7 API gravity, 5.5% by weight of sulfur and 13% by weight of Ramsbottom carbon content.

The temperature of regeneration zone 12 is maintained at 1800 F., primary conversion zone 16 at 975 F., and reflux zone 18 at 750 F.; a temperature gradient exists in secondary conversion zone 14 ranging from about 1000 F. at the top of this zone to about 1400 F. at its bottom. The temperatures of the various zones are maintained by circulating 35,000 pounds per hour of carrier from regeneration zone 12 to reflux zone 18 via transport tube 26 and 160,000 pounds per hour of carrier from regeneration zone 12 to primary conversion zone 16 via transport tube 24. The downward flow of carrier through regeneration zone 12 is thus 195,000 pounds per hour.

The products leaving reactor through outlet 44 are separated into various fractions by conventional methods.

The yields of these fractions are set forth in the second column of Table I. It is observed that the products are essentially high octane gasoline, furnace heating oil, and high heating value fuel gas, with only a very small quantity of heavy liquid product.

Table I Boscan Crude 10. 7 5. 5 Charge Rate, b./d 5,000

Without With Reflux Reflux Zone Zone Products, b./d.:

Gasoline 2. 040 2,670 Furnace Heating Oil (AS'IM No. 2) 1, 250 1,060 Fuel Oil (ASIM N0. 6) 750 80 Gaseous Products, MM s.c.f.d.:

Hydrogen 3. 72 4. 97 18 24 3.01 4.03 3. 19 4. 27 2. ll 2. 58 24 29 50 61 07 09 08 10 .48 51 472 43G Gasoline Inspections:

Octane Number, CFRR Clear 87. 7 88. 5 Octane Number-F3 cc. TE L 93. 6 94. 2 Fuel Oil Inspections:

Sulfur, wt. percent 7. 6 8.9 Viscosity, Saybolt-Furol seconds at 122 F--." 1,100 130 For purposes of comparison, the same charge stock oil is converted in a reaction system similar to that of Fig. l but without the reflux zone. The results are shown in the first column of Table I. As will be seen, a high percentage of the charge stock is converted to a very inferior heavy product which contains about 8% by weight of sulfur and has a viscosity which is unsatisfactory to meet ASTM No. 6 fuel oil specifications. In accordance with the invention, this unsatisfactory heavy product is not recovered but instead is converted to high octane gasoline, furnace heating oil and high heating value fuel gas, all of which are valuable products.

Various modifications of the invention will occur to those skilled in the art upon consideration of the foregoing disclosure without departing from the spirit or scope thereof. For instance, in Figure 2, duct 86 may be made longer so that its lower end communicates with secondary conversion zone 54. In such case, carrier with adsorbed hydrocarbons may be transferred from reflux zone 62 through duct 86 directly to secondary conversion zone 54 to effect conversion of the adsorbed hydrocarbons at a temperature higher than that maintained in primary conversion zone 50. Accordingly, only such limitations should 'be imposed as are indicated by the appended claims.

What is claimed is:

1. In the process for the conversion of a hydrocarbon oil wherein said oil is brought into contact with a heated particulate contact material in a conversion zone at an elevated conversion temperature and an oxygen-containing gas contacts said contact material transferred from said conversion zone in a regeneration zone at a regeneration temperature higher than said conversion temperature to consume carbonaceous matter deposited on said contact material by said oil, the improvement which comprises flowing the gasiform efliuent from said conversion zone through a dense-phase fluidized mass of said contact material suspended in a gasiform medium in a reflux zone, said efiluent having substantially the same composition as it leaves said conversion zone and enters said reflux zone, maintaining said reflux zone at a reflux temperature lower than said conversion temperature, substantially no conversion of said oil occurring at said reflux temperature, and controlledly passing said contact material with adsorbed hydrocarbons from said reflux zone to said conversion zone, thereby effecting conversion of said adsorbed hydrocarbons.

2. A process as defined in claim 1 wherein said conversion temperature is in the range of 850 to 1100 F. and said reflux temperature is not higher than 800 F.

3. A process as defined in claim 1 wherein a total pressure in the range of to 800 pounds per square inch gauge is maintained in said zones.

4. A process as defined in claim 1 wherein said conversion temperature is in the range of 900 to 1050 F. and said reflux temperatures are in the range of 600 to 750 F.

5. A process as defined in claim 1 wherein said oil is preheated by passage in indirect heat transfer relation with the dense-share fluidized mass of said contact material in said reflux zone prior to contacting said contact material in said conversion zone.

6. A process as defined in claim 1 wherein said contact material is bauxite.

7. A process as defined in claim 6 wherein said bauxite is regenerated at a temperature of at least about 1600 F. with a regenerating gas consisting essentially of steam and high-purity oxygen.

8. The process for the conversion of a hydrocarbon oil which comprises injecting said oil into a dense-phase fluidized mass of particulate contact material maintained at a conversion temperature in the range of 850 to 1100 F. in a conversion zone, reacting carbonaceous matter deposited on said contact material by said oil with steam and high-purity oxygen in a regeneration zone maintained at a regeneration temperature in the range of 1600 to 2500 F., passing regeneration product gases rich in hydrogen from said regeneration zone through said conversion zone, passing the resulting gasiform eflluent containing converted hydrocarbons and said regeneration product gases through a dense-phase fluidized mass of said contact material suspended in a gasiform medium in a reflux zone maintained at a temperature not higher than 800 F., said effluent having substantially the same composition as it leaves said conversion zone and enters said reflux zone, and controlledly transferring said contact material from said reflux zone to said conversion zone, from said conversion zone to said regeneration zone, and from said regeneration zone to said conversion zone.

9. A process as defined in claim 8 wherein a hydrogen partial pressure in the range of 35 to 200 pounds per square inch is maintained in said conversion and reflux zones.

10. A process as defined in claim 8 wherein said reflux zone is maintained at a temperature in the range of 600 to 750 F.

11. A process as defined in claim 8 wherein said oil is preheated by passage in indirect heat transfer relation References Cited in the file of this patent UNITED STATES PATENTS Ogorzaly Dec. 18, 1945 Jahnig Oct. 28, 1947 Blanding Feb. 17, 1948 Lewis June 28, 1949 Throckmorton et a1. Oct. 26, 1954 Keith Feb. 15, 1955 Jahnig Jan. 17, 1956

Claims

8. THE PROCESS FOR THE CONVERSION OF A HYDROCARBON OIL WHICH COMPRISES INJECTING SAID OIL INTO A DENSE-PHASE FLUIDIZED MASS OF PARTICULATE CONTACT MATERIAL MAINTAINED AT A CONVERSION TEMPERATURE IN THE RANGE OF 850 TO 1100F. IN A CONVERSION ZONE, REACTING CARBONACEOUS MATTER DEPOSITED ON SAID CONTACT MATERIAL BY SAID OIL WITH STEAM AND HIGH-PURITY OXYGEN IN A REGENERATION ZONE MAINTAINED AT A REGENERATION TEMPERATURE IN THE RANGE OF 1600 TO 2500* F., PASSING REGENERATION PRODUCT GASES RICH IN HYDROGEN FROM SAID REGENERATION ZONE THROUGH SAID CONVERSION ZONE, PASSING THE RESULTING GASIFORM EFFLUENT CONTAINING CONVERTED HYDROCARBONS AND SAID REGENERATION PRODUCT GASES THROUGH A DENSE-PHASE FLUIDIZED MASS OF SAID CONTACT MATERIAL SUSPENDED IN A GASIFORM MEDIUM IN A REFLUX ZONE MAINTAINED AT A TEMPERATURE NOT HIGHER THAN 800*F., SAID EFFLUENT HAVING SUBSTANTIALLY THE SAME COMPOSITION AS IT LEAVES SAID CONVERSION ZONE AND ENTERS SAID REFLUX ZONE, AND CONTROLLEDLY TRANSFERRING SAID CONTACT MATERIAL FROM SAID REFLUX ZONE TO SAID CONVERSION ZONE, FROM SAID CONVERSION ZONE TO SAID REGENERATION ZONE, AND FROM SAID REGENERATION ZONE TO SAID CONVERSION ZONE.
13. A PROCESS AS DEFINED IN CLAIM 8 WHEREIN SAID CONTACT MATERIAL TRANSFERRED FROM SAID CONVERSION ZONE TO SAID REGENERATION ZONE FIRST PASSES THROUGH A SECONDARY CONVERSION ZONE MAINTAINED AT A TEMPERATURE INTERMEDIATE SAID CONVERSION AND REGENERATION TEMPERATURES.