US2893942A - Hydrocarbon conversion process and apparatus - Google Patents

Description

JUHY 7, 1959 c. H; o. BERG 2,893,942

HYDRocARBoN CONVERSION PRocEss AND APPARATUS Filed March 22, 1954 '6b/0: Afd Mr HYDROCARBN CNVEIRSIN PRUCESS AND APPARATUS Clyde H. (l. Berg, Long Beach, Calif., assigner to Union Oil Company of California, los Angeles, Qalif, a corporation of California Application March 22, 1954, Serial No. 417,567

9 Claims. (Cl. 20d-66) This invention relates to an improved process and apparatus :for the continuous treating or contacting of fluids with a recirculating stream of solid granular contact material and in particular relates to the conversion of petroleum and other hydrocarbons in the presence of a recirculated stream of granular hydrocarbon conversion catalyst. In its most specific embodiment this invention contemplates an improved combination process and apparatus for the simultaneous treatment of two hydrocarbon fractions of substantially different properties, such as the catalytic reforming of naphtha or gasoline fractions and the catalytic desulfurization, denitrogenation, and deoxygenation of the reformed naphtha and a gas-oil fraction in the presence of a special catalyst which has reforming, desulfurization, denitrogenation, and deoxygenation activity and in which the hydrocarbon conversions cooperate with one another in an integrated process of increased eiciency.

The prior practice in hydrocarbon oil rening includes many catalytic operations wherein hydrocarbon fractions are treated and converted in a variety of processes to improve various physical and chemical properties thereof. Many hydrocarbon fractions contain undesirable impurities in the form of hydrocarbon derivatives of sulfur, nitrogen, and oxygen which render them uniit for their intended uses such as cracking stock, internal combustion engine fuels, and the like. In addition, the naphtha or gasoline fraction of these hydrocarbons contain insufficient quantities of hydrocarbon types having high antiknock characteristics and extensive refining operations are effected to increase the quantity of aromatic and branched chain hydrocarbons in these gasoline fractions to make them vsuitable for use as fuels in high compression engines. Accordingly, modern refining practice tends more and more toward catalytic treatment of such hydrocarbon fractions to remove undesirable fractions and to impart desirable characteristics thereto by such specific processes as catalytic desulfurization, catalytic denitrogenation, and catalytic reforming which involve paraffin hydrocarbon isomerization, dehydrogenation and cyclization, and naphthene hydrocarbon dehydrogenation to produce homologs of benzene which have high antiknock characteristics. The removal of hydrocarbon derivatives of oxygen, nitrogen, and sulfur are required to produce a sweet non-corrosive product having a high lead susceptibility and to avoid problems of corrosion.

rates patent The desulfurization and denitrogenation of the naphtha and gas-oil fractions of crude petroleum ordinarily require reaction temperatures ranging from about 575 F. t about 900 F., pressures between about 50 p.s.i. (pounds per square inch) to about 5000 p.s.i. in the presence of a recycled stream of hydrogen. The hydrocarbon compounds of sulfur, nitrogen, and oxygen are decomposed forming a hydrocarbon and either hydrogen sulfide, ammonia or water. In the reforming of low-grade gasoline fractions, the naphtha vapor is contacted with a reforming catalyst at temperatures between about 800 F. and about 1100 F. at pressures in substantially the same range as for desulfurization, and in the presence of a hydrogen gas recycle. Although desulfurization, denitrogenation, and reforming all have desirable beneficial effects upon low-grade gasoline, the difference between the optimum reaction temperatures of these processes and the fact that the hydrogen sulfide, ammonia, and water contaminate the hydrogen recycle stream employed in the first-named operation, have heretofore necessarily required that these operations be effected entirely separately under conditions requiring separate gas plants, and unduly complicated processing steps and apparatus.

It has been found that granular catalyst of the cobalt molybdate type, supported on activated alumina carriers and analyzing between about 2% and 10% by weight of cobalt oxide (COO) and between about 5% and about 30% by weight of molybdenum trioxide (M003), is highly stable, rugged, and relatively inert to materials which conventionally poison reforming and desulfurization catalysts. It has also been found that catalysts of this type are simultaneously highly active in promoting the rates of reactions involved in hydrocarbon desulfurization, denitrofgenation, deoxygenation, and reforming.

Accordingly, the present invention is directed to a novel and highly ecient integrated process wherein low-grade naphtha or gasoline fractions are catalytically reformed under optimum reforming conditions and gasoil fractions are desulfurized and denitrogenated also at optimum reaction conditions simultaneously in a single contacting column of unique design and in the presence of one granular catalyst consisting essentially of cobalt molybdate which is recirculated through the column. By means of a particular scheme of simultaneous operation of the desulfurizing and reforming zones in the contacting column, more specifically defined below, it is found that there exists apparently an active cooperation between the two operations whereby novel and unexpected results have been obtained and which are apparently unobtainable when the two operations are conducted separately.

It is therefore a primary broad object of the present invention to provide a new and improved huid-solids contact process.

It is a more specific object of this invention to provide an improved integrated hydrocarbon conversion process for the simultaneous desulfurization and reforming in a single contacting column.

It is an additional object of this invention to provide in a single contacting zone a downwardly moving bed of granular cobalt molybdate catalyst and in which contacting zone a naphtha fraction is reformed in the lower portion thereof and then the reformed naphtha and a contaminated gas-oil fraction, containing hydrocarbon 3 derivatives of sulfur, nitrogen and/or oxygen, are simul taneously treated in the upper portion of the contacting zone for the desulfurization, denitrogenation, and deoxygenation thereof.

It is a more specific object of this invention to provide a hydrocarbon conversion process, employing a recirculatory stream of granular catalyst, the improved steps of splitting the moving bed of catalyst in the contacting or reaction column into two streams, one of which being passed through the desulfurization zone directly and then indirectly-through Ithe reforming zone While the second of said streams passes indirectly through the desulfurization zone and then directly through the reforming zone.

It is an additional object of this invention to provide in a hydrocarbon conversion process employing a recirculated solid catalyst stream a novel and improved catalyst elutriation step for solids fines removal, and a novel hydrogen pretreatment step which substantially eliminates from the reactor efuent elemental sulfur and sulfur containing hydrocarbon compounds.

It is also an object of this invention to provide an apparatus for accomplishing the aforementioned objects.

Other objects and advantages of this invention will become apparent to those skilled in the art as the description thereof proceeds.

Briefly the present invention comprises an `improved combination process for the simultaneous desulfurization, denitrogenation, and deoxygenation (heretofore and hereinafter referred to collectively as desulfurization) of gasoil and naphtha hydrocarbon fractions simultaneously with the reforming of the naphtha fraction in a single contacting column or zone which includes isolated and yet communicating desulfurization and reforming zones through which a moving bed of granular catalyst is passed. Preferably the granular catalyst is of the cobalt molybdate type referred to above which has reforming and desulfurization activity. The contacting zone employed in the present invention `is provided with a desulfurization zone in the upper portion and a reforming zone in the lower portion and a moving bed of granular cobalt catalyst passes downwardly by gravity through each zone. The spent catalyst removed from the contacting zone and containing a deactivating hydrocarbonaceous deposit is recirculated to the top of the contacting zone through a regeneration zone in which the hydrocarbonaceous deposit is burned from the catalyst to restore its former activity.

In the modification, illustrated in Figure 1, the entire catalyst stream is divided into a first and a second stream. The first stream is passed directly into and downwardly as a moving bed through the desulfurization zone wherein it is directly contacted by a mixed stream of gas-oil, naphtha, and hydrogen. The first stream then passes downwardly indirectly through and in heat exchange relationship to the reforming zone in the lower portion of the contacting column and out of direct contact with the naphtha and hydrogen passing therethrough. The second stream of catalyst passes downwardly indirectly through and out of contact with the reactants in the desulfurization zone and then downwardly through the subjacent reforming zone in direct contact with the naphtha and hydrogen reactants therein. These first and second strearns of catalyst are combined in the lower portion of the reforming zone wherein the combined stream is contacted with the naphtha feed -to the reforming zone whereby an extremely eicient stripping of re sldual gas-oil is effected from the catalyst originating in the iirst stream. In this modification, freshly regenerated cobalt molybdate catalyst is fed to both the desulfurrzation and the reforming zones in the single contacting zone or column, the spent catalyst from the desulfurization zone which passes downwardly in indirect heat exchange through the reforming zone is heated from the lower desulfurization temperature substantially to the higher reforming temperature in the presence of a countercurrent stream of naphtha whereby all traces of residual gas-oil are stripped therefrom, and then the mixed streams of spent catalyst are further contacted by 'the full reactant naphtha and a hydrogen mixture prior to steam stripping of the spent catalyst and removal thereof for conveyance -to the regeneration system.

In the process of this invention, the endothermic reactions characterizing naphtha reforming and the exothermic reactions occurring during desulfurization, denitrogenation and deoxygenation in the desulfurization zone, normally result in the generation and maintenance of temperature gradients if the reaction zones are permitted to operate adiabatically. Reforming reaction rates decrease significantly with relatively small decreases in temperature and difiicultly controllable hydrogenation reactions may occur if the termperature is permitted to increase unduly in the desulfurization zone. Accordingly, in the present invention the reacting mixture of naptha and hydrogen is preferably heated at one or more points along the length of the reforming zone and the reacting mixture of gas-oil and naphtha vapor Y and hydrogen is cooled at one or more points along the length of the desulfurization zone to maintain the average reaction temperature in each of said zones substantially uniform at the optimum value.

In the reforming zone of the process of the present invention, naphtha vapor and between about 500 and 10,000 s'.c.f. of hydrogen per barrel of naphtha are passed in contact with a cobalt molybdate catalyst at a liquid hourly space velocity (L.H.S.V.) of between about 0.2 and 2.0, at temperatures between about 800 F. and 1000 F., preferably about 900 F., and at a pressure of between p.s.i. and 5000 p.s.i., preferably between about 50 and 1000 p.s.i. such as about 400 p.s.i. to dehydrogenate and cyclize paraffin hydrocarbons and to dehydrogenate naphthalene hydrocarbons to produce a highly aromatic reformed gasoline product containing branched chain hydrocarbons and having a knock rating of above 92. Heat is added along the length of the reforming zone to maintain a uniform temperature profile therein by means more fully described below.

. The reformed naphtha and the recycle hydrogen stream,

which now contains excess hydrogen produced during the reforming, is mixed with the gas-oil to be treated. The gas-oil may be partly or completely vaporized, but in any event is preferably at a temperature whereby admixture with the eluent from the reforming zone will produce a mixture having a temperature of about 775 F., which is the optimum preferred gas-oil and naphtha desulfurization temperature.

This mixture of gas-oil, naphtha and hydrogen is passed at the reduced temperature of from about 575 F. to 900 F., at a L.H.S.V. between about 0.2 and 15.0, at substantially the same pressure, and `with from 50 to 5000 s.c.f. per barrel of hydrocarbon, through the desulfurization zone wherein the naphtha and gas-oil are simultaneously desulfurized, denitrogenated, and deoXy-genated to produce respectively, hydrogen sulfide, ammonia, and water vapor. The hydrocarbons remaining are hydrogenated to stable hydrocarbon products maintaining a high liquid product yield. These reactions consume the excess hydrogen which was generated as described during the reforming step. In doing so, considerable heat is liberated and accordingly the reactant mixture is prefer#v guesses 5. trogen, and oxygen content of thelgas-oil so that during the reforming step the naphthene dehydrogenation proceeds sufficiently -to liberate a quantity of hydrogen which is equal to or greater than that necessary to fully desul- Ifurize, denitrogenate, and deoxygenate both the gas-oil and the naphtha. Thus a hydrogen balance is reached and no outside sources of hydrogen are required. This is one of the advantages of the present invention which, together with the requirement of only a single catalyst, namely cobalt molybdate, the means for temperature control in the desulfurzation and reforming zones, the use of separate cobalt molybdate catalyst streams within a single contacting zone to treat two `hydrocarbon streams, the naphtha stripping of the combined catalyst streams to permit total recovery of gas-oil thereby eliminating the usual gas-oil loss, and the subsequent steam stripping of the spent catalyst to recover the naphtha therefrom, yields an integrated process which permits simultaneous treatment of two related hydrocarbon fractions to produce premium-grade internal combustion engine fuels. By locating the desulfurization zone above the reforming zone and subsequently passing the spent desulfurization catalyst stream through the reforming zone, either directly or indirectly, the temperature of the spent desulfurization catalyst is raised in the presence of a naphtha and hydrogen flow which has lbeen found to permit the highly efficient gas-oil stripping from the catalyst with substantially no loss due to catalytic cracking. In the modification shown in the figure wherein spent catalyst from the desu'lfurization zone passes indirectly through the reforming zone, the same eect results in that the catalyst is gradually heated within the tubes and in the presence of a small countercurrent ow of naphtha and hydrogen which passes upwardly therethrough.

The mixture of gas-oil, naphtha, and hydrogen is removed from the reactor eflluent at the top of the contacting Zone, cooled, partially condensed, and the vapor remaining is separated from the liquid. The gas fraction contains recycle hydrogen together with hydrogen sulfide, ammonia, and water vapor which may be separated from the recycle hydrogen by conventional means. It is preferred that the hydrogen recycle contain at least hydrogen by volume and preferably more'than 70% hydrogen by volume. The liquid fraction comprises a mixture of naphtha and lgas-oil which is substantially free of sulfur, nitrogen, and oxygen and the naphtha fraction of which consists essentially of branched chain paraiin hydrocarbons and aromatic hydrocarbons and is an excellent blending stock for premium and aviation gasolines.

In the process of the present invention, it has been found that the required catalyst recirculation is low and the permissible on-stream time of the catalyst is long and therefore the regeneration of the catalytic material is quite simple. Although the spent catalyst removed from the bottom of the contacting zone may be passed through a separate regeneration Zone in lwhich the solids flow downwardly as a moving bed, it is a preferred form of this invention to convey the granular solids from the bottom to the top of the column through an elongated conveyance conduit in 'which the granular solids are maintained in compact dense packed form, that` is, as a mass having a ybulk density substantially equal to the static bulk density of the solids when at rest. The conveyance fluid employed is a regeneration gas such as a mixture of flue gas to which air or oxygen has been added to produce a regeneration gas mixture containing between about 1% and about 5% oxygen by volume at the bottom of the lift line. This combination conveyance-regeneration gas is passed through the conveyance zone at a rate sucient to convey the granular solids upwardly as a compact mass. 'Ilhe fluid and the solids ow concurrently at a relatively low rate and are regenerated during conveyance. The spent regeneration gases are removed at the top of the conveyance conduit, and the red generated solids are circulated into the top of the contacting zone.

It has been found that in spite of the regeneration of the catalyst, from 20 to 40% of the sulfur present on the spent catalyst remains, possibly in the form of cobalt or molybdenum suldes or the like, the constitution of which is not known. It has been determined that when such regenerated catalyst is introduced directly into the desulfurization zone and contacts the hydrogen sulfide-containing gas there, the hydrogen sulfide in some way reacts with the suliided regenerated catalyst to produce elemental sulvfur. This sulfur is carried out with the reactor effluent and renders the product sour and corrosive. It has Ibeen found that by treating the regenerated catalyst with a countercurrent stream of hydrogen recycle gas substantially free of hydrogen sulfide, the sulfur on the catalyst is liberated as sulfur and sulfur dioxide in a reaction generating considerable heat, and the presence of elemental sulfur in the product is fully eliminated. The character of the reaction is not fully understood, but its effect upon the physical properties of the product is remarkable for the effluent gasoline is sweet.

The conveyance of spent catalyst to a separate regeneration zone and its` regeneration therein during downward ofw therethrough as a moving bed is conventional and will not be described in further detail. However, the modification wherein the spent catalyst is conducted upwardly as a moving bed through a conveyance-regeneration zone is a novel type of regeneration and the details of its operation will be briefly described below.

The pressure drop characteristic of this type of solids conveyance is of the order of times that characteristic of pneumatic or gas lift (suspended) solids conveyance and the volume of gas required to convey dense packed solids is only a few percent of that .required in gas lift. The granular solids to be conveyed are removed from the bottom of the contacting column at substantially the reforming pressure, are passed through a solids pressuring zone to increase the pressure of gases associated with the solids by an amount substantially equal to the characteristic pressure drop of the conveyance conduit, and then the solids are passed into the conveyance element of the apparatus.

The inlet of the conveyance-regenerator conduit is thus maintained at a relatively higher pressure generally than the pressure of the solids before introduction into the conveyance conduit. The granular solids are then transferred through the conveyance conduit in compact dense packed form by means of a concurrently depressuriug conveyance-regeneration fluid. The frictional forces generated by the uid depressuring through the interstices of the compact mass of solids generate a pressure gradient in the conduit sufcient to counteract opposing forces of friction of the solids sliding against the walls of the conduit as well as the opposing force of gravitation and thereby establish a conveying force permitting movement of the compact porous granular mass in the direction of decreasing conveyance fluid pressure when solids are removed from the outlet and fed into the inlet.

The deprcssuring conveyance fluid generates a pressure drop per unit length of conduit (the pressure gradient) sufficient to overcome the opposing gravitational force (ps cos 0), wherein ps is the bulk density of the dense packed granular solids and 0 is the angular deviation of the conveyance conduit from the vertical. The ratio of the former to the latter is ,os COS 0 This factor is termed the conveyance force ratio and is the ratio of the force tending to move the solids through the conveyance conduit to the opposing forces of gravity tending to restrain such flow. The conveyance uid must be depressured through the conduit at a rate sufficient to raise the conveyance force ratio to a value greater than 1.0 (factors in consistent units) in order that the conveying force exceed the forces resisting flow. The amount by which the conveyance force ratio must exceed a value of 1.0 is equal to the magnitude of the friction forces also tending to resist solids flow.

The granular solids are maintained during conveyance and regeneration in the compact form by means of the application of a compressive force on the discharge solids issuing from outlet of the conveyance conduit. Various means are available for applying such a force which has the effect of restricting the discharge rate of `granular solids from the conveyance conduit but has virtually no effect on the discharge of the conveyance uid therefrom. A transverse thrust plate or a grid may be spaced opposite and adjacent the outlet opening and against which the mass of solids discharges, or a static bed of solids may be used to submerge this outlet. The rate of solids conveyance is determined by the rate of solids removal from the contacting column which is full of dense packed solids in the form of a moving bed. The solids feeder at the column bottom controls this variable as described below. 4

The present invention will be more clearly understood by reference to the accompanying drawings in which:

Figure l is a schematic flow diagram of the process of this invention including an elevation view in cross section showing the details of the contacting column,

Figure 2 shows a cross-sectional view of the detail of the top part of the structure of Figure l.

Referring now more particularly to Figure l, contacting column is divided into three major contacting zones including first treating or desulfurization zone 12, second treating or reforming zone 14, and combination third treating or reforming and stripping zone 16. Contacting column 10 is provided at successively lower levels therein with treating gas injection zone 96, hopper and seal zone 18, effluent disengaging zone 20, second desulfurization zone 22, cooling zone 24, first desulfurization zone 26, gas-oil and naphtha engaging zone 28, naphtha disengaging zone 30, third reforming zone 32, heating zone 34, second reforming zone 36, first and second catalyst stream rate control zone 38, first reforming and naphtha stripping zone 40, naphtha engaging zone 42, hydrogen stripping zone 43, hydrogen engaging zone 44, stripping zone 45, stripping gas engaging zone 46, and catalyst feeder zone 48.

The granular catalyst introduced into hopper zone 18 as a single stream is divided into a first and second stream in the etlluent disengaging zone 20. The first stream passes downwardly through the annular space between downcomers 50 and primary tubes 52 directly into and 1 through desulfurization zone 12 while the second stream passes downwardly indirectly through the desulfurization zone and out of contact with the reactants therein through primary tubes 52. This second stream of catalyst is discharged at naphtha disengaging zone 30 wherefrom it passes downwardly as a moving bed through reforming zone 14. The spent catalyst withdrawn from the bottom of desulfurization zone 14 passes downwardly indirectly through and out of direct contact with the reactant uids in reforming zone 14 by means of secondary tubes 54 provided at their lower ends with solids flown control valves 56. The spent solids are withdrawn from the bottom of reforming zone 14 through downcomers 58 provided with solids ilow control valves 60. The two streams of solid catalyst are thus combined in rst reforming and naphtha stripping zone 40 wherein the entire catalyst stream is contacted with feed naphtha and hydrogen as described more fully below. The relative volumetric rate of catalyst flowing in the first and second streams, that is, the relative rates of catalyst ow through the desulfurization and the reforming zones respectively, are controlled by means of the relative adjustment of ow control valves v56 and 60. It is not necessary that these control elements be valves, for orifices of fixed or variable area may be substituted at this point in the apparatus so as to control the relative solids ow rate. Orices are entirely effective since the ow of solids through an orifice is substantially unaffected by the depth of the bed of solids above the orifice provided this depth is greater than two or three orice diameters. Since the ow of solids through an orifice is inhibited by countercurrent uid flow therethrough, vapor risers and caps 62 are provided which effectively bypass the reactant naphtha through tray 64 thus preventing any vapor flow interference with the solids ow.

The absolute circulation rate of granular solids through column 10 is fixed by reciprocating tray solids feeder 48 located in the bottom of the column. The details of this apparatus element are not shown because they are well-known in the art. This element also provides for a uniform removal of spent catalyst throughout the entire cross-sectional area of the column and this uniformity of solids flow is reflected throughout the height of the column when primary tubes 52, secondary tubes 54, and the other tubular elements of this apparatus are uniformly distribu-ted throughout the cross-sectional area of the column.

The combined stream of spent granular solids passes downwardly into solids pressuring means 66 in which the spent granular catalyst is pressured from the reaction pressure to a higher pressure exceeding the reaction pressure by an amount substantially equal to the required pressure differential for conveying the spent catalyst as a substantially compact upwardly moving bed through conveyance-regeneration conduit 68. The details of solids pressuring means 66 are not shown for they are described in copending application Serial No. 217,337 filed March 24, 1951, now U.S. Patent Number 2,695,212. The spent catalyst is pressured by means of high pressure gas, preferably inert such as oxygen-free flue gas, introduced through line 70 controlled by valve 72. The thus pressured solids then are passed downwardly to submerge inlet Opening 74 of the conveyanceeregeneration zone. A conveyance-regeneration gas, containing between about 1% and about 5% by volume of oxygen, is introduced through line 76 at a rate controlled by valve 78 and passes downwardly concurrently with the pressured spent catalyst which ows by gravity into inlet opening 74, or the oxygen concentration in line 68 may be maintained by injection of the oxygen containing gas directly into the line as through line 71 controlled by valve 73. This conveyance-regeneration fluid is depressured concurrently through conveyance-regeneration zone 68 as described above and the spent catalyst is simultaneously conveyed and regenerated during transit upwardly through the conveyance regeneration zone. In the present process, the catalyst circulation rate is quite low and the heat generated by regeneration may be carried out of the system with the spent regeneration gases as subsequently described, or a jacket or vessel may be provided surrounding conveyance zone 68 whereby a coolant may be passed around zone 68 to remove heat in this way.

The spent regeneration gases discharging from zone 63 with the regenerated solids preferably contain less than 1% Oxygen. The regenerated catalyst discharges into solids receiving and elutriation zone 80 directly against batile 82 whereby a solids thrust or compacting force is applied to the discharging catalyst preventing its fluidization and maintaining the granular solids during conveyance and regeneration at a bulk density substantially equal to the bulk density of the downwardly moving beds of catalyst in contacting column 10. The spent regeneration gas is disengaged from the solids through inclined surface 87 of the discharged solids and is removed from the top of solids receiving zone 80 through outlet 81 and aperture 83 and linef84 at a rate controlled by valve 86 which is actuatedV by back pressure regulator 88. These gases, in being disengaged from the discharged solids, act as an elutriation medium and suspend and carry out solids fines. The degree of elutriation is variable, as described in Connection with Figure 2 by varying the area open to gas disengagement. The regeneration-elutriation gas is removed at substantially the same pressure as the operating pressure in contacting column 10, and may be repressured and recirculated through the regeneration zone with added oxygen.

Referring now to Figure 2, a plan view in cross section of solids-receiving chamber 30 is shown. Herein are shown the crossed vertical baffles 79 extending downwardly into the discharged solids forming 4, 6, 8, or more individual circularly disposed elutriation chambers of pie-shaped cross section. Only 4 chambers are shown for purposes of illustration. Gas outlet 81 is provided centrally, between the individual chambers, and is provided with `one or more openings 83. Thus, with one such opening, only the solids disengaging area in one individual chamber is active and the gas velocity therein is relatively high because of the relatively constant conveyanceregeneration gas ow through the lift line and the thus reduced area of solids through which it is disengaged. By using more such openings, more of the individual elutriation chambers actively disengage gas and the disengagement velocity is lower. With the greater velocities of disengagement larger solids fines are suspended and carried out, and reductions in velocity as described reduce the size of the particles suspended and removed.

The regenerated cobalt molybdate catalyst, freed of solids fines, passes downwardly in the form of compact bed 90 over treating gas disengaging zone 92 and then downwardly through inlet conduit 94 into the top of column 10. The lower opening of inlet g4 is surrounded by treating gas injection collar 96. Hydrogen sulfide-free recycle hydrogen is introduced by means of line 98 at a rate controlled by valve 100 and flow recorder controller 102 into collar 96. This treating gas splits into two streams, the first passing downwardly concurrently with the catalyst through hopper zone 18, and the second passing upwardly through inlet `94 and through treating zone 104 in the lower portion of solids receiving Zone d0. This latter hydrogen stream countercurrently contacts the regenerated catalyst, causes the liberation therefrom of the residual quantities of lsulfur in the form of sulfur and sulfur dioxide which are removed from treating gas disengaging zone 92 through line 103 at a rate controlled by valve 106 in accordance with differential pressure controller 110 which maintains a positive pressure differential between the extremities of inlet zone 94. This differential pressure is quite small, of the ord-er of a. few inches of water and serves to seal thewtop of the column against hydrogen sulfide contacting the regenerated catalyst. In this manner the reactor eiiiuent is maintained entirely free of elemental sulfur and a long standing problem has been eliminated whereby the conventional post treating operations on the product to render it sweet and non-corrosive are avoided.

The remainder of the description of Figure l will be conducted as an illustrative example of the process of the invention in which a straight run naphtha and a straight run gas-oil are simultaneously treated by the process of this invention. Both the naphtha and the gas-oil are heavily contaminated with sulfur and nitrogen and their physical properties are as follows:

TABLE l Naplztlm feed Gravity, API 49.8 Boiling range, F 200-400 Sulfur, weight percent 0.10

Boiling range, F 500-900 Sulfur, weight percent 3.76 Nitrogen, weight percent 0.24

The naphtha feed rate is 1000 barrels per day and the gas-oil fed rate is 500 barrels per day. The total catalyst circulation rate is 14 tons per day, the rate through the desulfurization zone being 4 tons per day, and the rate through the reforming zone being 10 tons per day. The desulfurization and reforming zones are maintained at a pressure of about 400 p.s..a. (pounds per square inch absolute), the temperature ofthe reforming zone is maintained at an average of 900 F. and the temperature of the desulfurization zone is maintained at an average of 750 F.

The naphtha feed passes from storage through line by means of naphtha feed pump 122 at the above-mentioned rate controlled by valve 124 and ow recorder controller 126 through line 128 and interchanger 130. Herein the cold feed is exchanged with part of the reactor euent described -below and is raised to a temperature of 600 F. The preheated naphtha then flows through line 132 through naphtha preheating and vaporizing coil 134 in furnace 136. The naphtha vapor then passes by means of line 138 into naphtha engaging zone 42.

Recycle hydrogen, necessary in the operations conducted in this process, and separated from the reactor effluent as described below, iiows through line 140 into gas purier 142. Herein, by conventional means, hydrogen sufide, ammonia, and water vapor are separated from the recycle gas and if desired any low molecular weight hydrocarbon gas which may be present such as meth-ane, ethane, and the like `may also be removed through line 143. The hydrogen thus treated then flows through line 144 together with additional hydrogen, if necessary, injected through line 146 controlled by valve 148 and is pumped by means of recycle blower 150 at a rate controlled by Valve 152 and flow recorder controller 154 through hydrogen heating coil 156 in furnace 136. The heated hydrogen, at a temperature of about 900 F. passes through line 158 at a rate of 3000 M s.c.f./d. (thousand standard cubic feet per day) into hydrogen recycle engaging zone 44. 'Under the influence of a seal or stripping gas such as steam introduced through line 160 controlled by valve 162 into engaging Zone 46 at a slightly higher pressure, substantially all of the hydrogen recycle gas passes upwardly from zone 44 and is combined with naphtha vapor in engaging zone 42 to form a reactant naphtha. and hydrogen mixture which passes through the reforming zone as described in detail below.

The reactant mixture of naphtha and hydrogen passes upwardly through first reforming and naphtha stripping zone 40 countercurrently to the combined catalyst streams. Herein the initial catalytic reforming of the naphtha takes place simultaneously with exothermic hy drogenation of any olenic constituents in the naphtha feed. The temperature rises somewhat to values preferably not exceeding about 925 F. This maximum ternperature is controlled by reducing the naphtha vapor inlet temperature so that .olefin hydrogenation does not raise the temperature above a valueY of that given. Simultaneously in Zone 40, a highly effective naphtha and hydrogen stripping of that part of the catalyst introduced thereinto from desulfurization zone 12 takes place. Substantially all of the residual gas-oil present on the catalyst is removed thereby and vaporized leaving a. spent reforming catalyst containing traces-of adsorbed naphtha but substantially gas-oil free. As stated above, this spent catalyst is steam stripped in zone 4.5 immediately above stripping gas engaging zone 46 and the naphtha is returned upwardly into the reactant mixture and passes upwardly therewith. In` this manner substantially no gas-oil or naphtha feed is lost by oxidation in the spent catalyst regeneration step and maximum liquid product yields of the order of 95% to 99% are obtained.

The reactant mixture of naphtha and hydrogen, together with minor amounts of gas-oil vapor stripped from the catalyst, passes upwardly through vapor risers and caps 62 into and countercurrently through second reforming zone 36. Herein additional aromatization takes place causing the temperature to drop toa value of preferably not less than 875 F. by the time it reaches heating zone 34.

At this point the naphtha reactants are reheated to a temperature of about 900 F. or slightly higher for subsequent passage through third reforming zone 32. Preferably the disengaging-engaging structure shown in the drawing is employed which consists of upper tray 166, lower tray 168 with a plurality of seal tubes 170 open at both ends and extending from above tray 166 through and to a point below lower tray 168. Seal tubes 170 pass the catalyst downwardly therethrough creating a path having a relatively high resistance to reactant vapor ow.

Accordingly only a minor portion of the reactant vapor mixture passes upwardly through tubes 170 generating a pressure differential of about 1.0 p.s.i. which is sufficient to force the major portion of the mixture from lower disengaging zone 172 through line 174, into and through interheater 176 wherein the temperature is increased to compensate for the temperature drop occasioned by en dothermic reforming reactions in reforming zone V36 and the prospective temperature drop in zone 32. The reheated mixture is then passed through line 178 into engaging zone 180 wherefrom it passes upwardly through vapor risers 182 into the bottom of third reforming zone 32.

Herein the reheated vapor mixture Ycontacts fresh reforming catalyst and additional `aromatization takes place causing a further temperature decrease. The naphtha reforming zone effluent, containing aromatized naphtha vapor together with an excess of hydrogen recycle produced during the reforming, is disengaged from the catalyst in zone 30 andpassed through line 184 controlled by valve 186 and is preferably combined outside of contacting column with the gas-oil vaporto be treated with the reformed naphtha in desulfurization zone 12.

The gas-oil to be converted is introduced through line 188 and pumped by means of pump 190 at a rate of 500 barrels per day controlled by valve 192 and ow recorder controller 194. The gas-oil flows through line 196 through preheater 198 in exchange with the remaining part of the reactor effluent. The preheated gas-oil at a temperature of about 650 F. flows through line 200 into and through gas-oil heating and vaporizing coil 202 in furnace 204. Herein a partial or complete vaporization of -gas-oil is effected, depending upon its end point, and the gas-oil is combined in line 206 with the naphthahydrogen efiluent from reforming zone 14. The furnace 204 is controlled to have an outlet temperature such that upon adrnixture of the thus heated gas-oil with the etliuent naphtha vapor flowing from third reforming zone 32, the temperature of the resulting mixture is substantially equal to the preferred desulfurization temperature, that is, about 750 F. In the present example the furnace outlet temperature was about 650 F. and the temperature of the naphtha mixture owing into line 208 from reforming zone 32 was 900 F.

It is possible to permit thev reformed naphtha vapor to pass directly from reforming zone 14 into the bottom of desulfurization zone 12 and to' inject the gas-oil into the upwardly `from engaging zone 28 through vapor risers 210 and then through rst desulfurization zone 26 countercurrent to the downwardly owing first stream of cobalt molybdate catalyst. Herein, under the temperature and pressure conditions given, the sulfur, nitrogen, and oxygen compounds are destructively hydrogenated forming the corresponding hydrocarbon derivatives together with hydrogen sulfide, ammonia, and water vapor. Depending upon the extent of gas-oil and naphtha contamination with these compounds, more or less heat is liberated in rst desulfurization zone 26 and the temperature of the reactant vapor mixture rises to a value of about 780 F. after passage therethrough. In a manner entirely analogous with the disengaging and engaging of the reactant naphtha vapor -described in connection with heating zone 34, the reactant mixture is disengaged, cooled, and engaged in cooling section 24. This section is provided with upper tray 212 and lower tray 214 forming disengaging zone 216 and engaging zone 218. Catalyst seal tubes 220 are equivalent to tubes described above. As before, a minor portion of the reactant vapor passes upwardly through the restricted passageway formed by tubes 220 generating a pressure drop which forces the major portion from disengaging zone 216 through line 221 and intercooler 222 and then back through line 224 into engaging zone 218. In this example intercooler 222 serves to decrease the temperature of the reactant mixture to about 750 F. at which it enters second desulfurization zone 22 through vapor risers 226.

Further desulfurization takes place in second desulfurization zone 22 which serves to remove substantially al1 the residual sulfur, nitrogen and oxygen contaminants therein. The temperature rises somewhat to a value of about 770 F. and accumulates in effluent disengaging zone 20 from which it is removed with a small portion of hydrogen passing downwardly with the catalyst through hopper zone 18. The reactor effluent includes the naphtha and gas-oil vapors substantially free of the aforementioned contaminants together with moderate amounts of hydrogen sulfide, ammonia, water vapor, hydrogen, and small amounts of low molecular weight hydrocarbon gases.

The reactor eftluent passes from disengaging zone 20 through line 228, and is divided into two streams which pass through gas-oil preheater 198 and through naphtha preheater 130. Eiuent cooling and condensation takes place and then the combined streams pass through line 230 through product effluent cooler 232 and through line 234 into vapor liquid separator 236.

The condensed liquid product accumulates in the lower portion of separator 236 and is removed therefrom through line 238 controlled by valve 240 and liquid level controller 242. This liquid product contains some water and consists essentially of gas-oil and naphtha mixture. By means of conventional techniques, the water is separated as by settling and decantation and the hydrocarbon product is fractionated into a reformed desulfurization gasoline fraction and a desulfurized gas-oil fraction having excellent cracking qualities and containing a large fraction of hydrocarbons suitable for 50 cetane diesel fuel or jet engine fuel. Upon such fractionation 952 barrels per' day of C4-free reformed gasoline having a 400 F. end point are obtained, amounting to a liquid naphtha yield of 95.2%. The physical properties of this gasoline are as follows:

TABLE 3 Reformed gasoline product Gravity, API 50.4 Boiling range, F 100-420 f Sulfur, weight percent 0.002 Nitrogen, weight percent Nil Knock rating, F-l Clear 85.2 Knock rating, 3 ml. TEL 91.8

The production of desulfurized gas-oil amounts to 550 lf3 barrels per day, liquid yield oflgas-oil-.of 10.1%, and its physical properties are as follows:

The uncondensed portion of the reactor efuent is removed from separator 236 through line 244 and is ordinarily divided into two streams. The first stream passes through line 140 to provide the recycle hydrogen ernployed in the process as described above. Any net production of hydrogen, which may result when rhighly naphthenic gasolines are reformed and desulfurized in the presence of a gas-oil which either contains relatively small amounts of sulfur or whichvis fed to the system at relatively low rates, is bled from the system through line 246 at a rate controlled by valve 248 and back pressure regulator 250 which maintains the operating pressure on the system. In the present example, the relative feed rates and compositions were such that no net hydrogen is produced and no net consumption of hydrogen takes lace.

p In this invention the desulfurization, which term is used to include denitrogenation and deoxygenation, takes place in the upper portion of the contacting column and the naphtha reforming is effected in the lower portion of the column. In the process, one or more interheaters or intercoolers are employed in the reforming or desulfurization zones respectively depending upon the degree of uniformity of the reaction temperature desired. Only one intercooler and interheater has been shown and described for sake of clarity, but it should be understood that as many as 8 or 10 of such heaters can be employed in the present apparatus.

Although other catalysts having desulfurization and reforming activities may be employed or a mixture of known catalysts including a desulfurization catalyst and a reforming catalyst can also be used, the preferred catalytic agent to be used in this process yis the cobalt molybdate type containing cobalt and molybdenum oxides in the amounts given above because these have been found to be extremely stable under reforming and desulfurization conditions and in addition have been found to have simultaneously very high activities for reforming, desulfurization, denitrogenation, and deoxygenation properties which are not found in other known catalysts. c

Cobalt molybdate catalysts in general comprise mlxtures of cobalt and molybdenum oxides wherein the molecular ratio of CoO to M003 is between about 0.4 and 5.0 and are prepared as described below. This catalyst may be employed in unsupported form or alternatively 1t may be distended on a suitable carrier such as alumina, silica, zirconia, thoria, magnesia', magnesium hydroxide, titania or any combination thereof. Of the foregoing carriers it has been found that the preferred carrier matenal is alumina and especially alumina containing about 38% by weight of silica.

In the preparation of the unsupported cobalt molybdate, the catalyst can be coprecipitated by mixing aqueous solutions of, for example, cobalt nitrate and ammonium molybdate, whereby a precipitate is formed. The precipitate is ltered, washed, dried and finallyv activated by heating to about 500 C.

Alternatively, the cobalt molybdatel may be supported on alumina by coprecipitating a mixture of cobalt, aluminum and molybdenum oxides. A suitable hydrogel of the three components can be prepared by addingk an ammoniacal ammonium molybdate solution to an aqueous solution of cobalt and aluminum nitrates. The precipitate which results is washed, dried and activated.

In still another method, a washed aluminum hydrogel is suspended in an aqueous solution of cobalt nitrate and yan ammoniacal solution of ammonium molybdate is added thereto. By this means a cobalt molybdate gel is precipitated on the alumina gel carrier.

Catalyst preparations similar in nature to these and which can also be employed in this invention have been described in U.S. Patents 2,369,432 and 2,325,033.

Still other methods of catalyst preparation may be employed such as by impregnating a dried carrier material, eg. an alumina-silica gel, with an ammoniacal solution of cobalt nitrate and ammonium molybdate. Preparations of this type of cobalt molybdate catalyst are described in U. S. Patent 2,486,361.

In another method for preparing impregnated molybdate catalyst the carrier material may be first impregnated with an aqueous solution of cobalt nitrate and thereafter impregnated with an ammoniacal molybdate. Alternatively, the carrier may also be impregnated with these solutions in reverse order. Following the impregnation of the carrier by either of the foregoing methods the material is drained, dried and nally activated in substantially the same manner as is employed for the other catalysts.

In the preparation of impregnated catalysts where separate solutions of cobalt and molybdenum are employed, it has been found that it is preferable to impregnato the carrier first with molybdenum, eg., ammoniacal ammonium molybdate, and thereafter to impregnate with cobalt, exg., aqueous cobalt nitrate, rather than in reverse order.

ln another method for the preparation of suitable catalyst, a gel of cobalt molybdate can be prepared as described hereinbefore for the unsupported catalyst, which gel after drying and grinding can be mixed with a ground alumina, alumina-silica or other suitable carrier together with a suitable pilling lubricant or binder which mixture can Ithen be pilled or otherwise formed into pills or larger particles and activated.

In another modification, finely divided or ground molybdic oxide can be mixed with suitably ground carrier such as alumina, alumina-silica and the like in the presence of a suitable lubricant or binder and thereafter pilled or otherwise formed into larger agglomerated particles. These pills or particles are then subjected to a preliminary activation by heating to 600 C. for example, and are thereafter impregnated with an aqueous solution of cobalt nitrate to deposit the cobalt compound thereon. After draining and drying, the particles are heated to about 600 C. to form the catalyst.

It is apparent from the foregoing description of the different types of cobalt molybdate catalyst which may be employed in this invention that we may employ either an unsupported catalyst, in which case the active agents approximate of the composition, or we may employ a supported catalyst wherein the active agents, cobalt and molybdenum oxides, will generally comprise from about 7 to 22% by weight of the catalyst composition. In all of the foregoing catalytic preparations it is desirable to maintain the molecular ratio of cobalt oxide as CoO to molybdic oxide as M003 between about 0.4 and 5.0.

A particular embodiment of the present invention has been described in considerable detail by way of illustration. It should be understood that various other modications and adaptations thereof may be maintained by those skilled in the particular art without departing from the spirit and scope of this invention as set forth in the appended claims.

I claim:

l. A process for the simultaneous contacting of two uid streams of substantially different physical properties with moving beds of granular solid Contact material in a single conversion Zone which comprises dividing a stream of granular solid contact material into a first and a second stream at the top of said conversion Zone, passing the first solids stream downwardly as a moving bed through a first treating zone maintained at a relatively low contacting temperature and in direct contact with uid's passing therethrough, then passing said first solids stream downwardly therefrom through and in indirect heat exchange relation with a subjacent second treating zone maintained at a relatively high contacting temperature and out of direct contact with fluids passing therethrough whereby said solids stream is indirectly heated, simultaneously passing said second solids stream downwardly as a moving bed through and in indirect heat exchange relation with said first treating zone and out of contact with fluids passing therethrough, then passing said second solids stream therefrom downwardly through and in direct contact with tluids passing through said second treating zone, combining said first and second solids streams in and passing them together through a third treating and solids stripping zone, further stripping the combined solids stream with a stripping gas prior to removal of said solids from said conversion zone, transferring the spent stripped solids thus formed through a regeneration zone and regenerating said solids therein, elutriating fines from the regenerated solids, contacting said regenerated solids with a treating gas immediately prior to introducing said solids into said conversion zone for repassage therethrough, passing the higher boiling fluid stream at said relatively low contacting temperature through said rst treating zone, passing the lower boiling liuid at said relatively higher temperature first through said third treating and stripping zone in direct Contact with the combined first and second solids streams to effect an initial iluid conversion and to strip residual quantities of said higher boiling fluid from the combined solids stream therein, then passing the lower boiling fluid through said second treating zone to contact said second solids stream for further conversion, and then passing said lower boiling fluid through said first treating zone at said relatively low temperature to contact said first solids stream together with said higher boiling fluid, and removing a combined converted fluid eliiuent from the top of said conversion zone.

2. A process for simultaneous conversion of gas-oil and naphtha hydrocarbon fractions in the presence of a recirculating stream of hydrocarbon conversion catalyst which comprises recirculating said catalyst through a hydrocarbon conversion zone containing a desulfurization and a reforming zone, and through a catalyst regeneration zone, dividing the regenerated catalyst into a rst and a second catalyst stream prior to passage of said catalyst through said conversion zone, passing said first catalyst stream into and directly through said desulfurization zone as a downwardly moving bed by gravity in direct contact with vapors passing therethrough and then through said reforming zone in indirect heat exchange relation thereto and out of contact with vapors therein, passing said second catalyst stream as a downwardly moving bed by gravity through said desulfurization zone in indirect heat exchange relation thereto and out of contact with said vapors and then into and directly through said reforming zone in direct contact with vapors passing therethrough, subsequently combining said first and second catalyst streams prior to removal from said hydrocarbon conversion zone, maintaining said desulfurization zone at a hydrocarbon desulfurization temperature and at a superatmospheric pressure, maintaining said reforming zone at a relatively higher hydrocarbon reforming temperature and at substantially the same superatmospheiic pressure, passing a naphtha hydrocarbon fraction and hydrogen first through the combined first and second catalyst streams to strip retained hydrocarbons therefrom and then through said reforming zone in contact with said second catalyst stream, combining the thus treated naphtha with a gas-oil hydrocarbon fraction, passing the naphtha, gas-oil, and hydrogen mixture thus formed into and through said desulfurizationzone in contact with said rst catalyst stream, removing an emuent therefrom, cooling and partially condensing said effluent, separating an uncondensed hydrogen-rich gas, recirculating at least partY thereof through said conversion zone, removing the combined catalyst stream from said conversion zone, regenerating said catalyst in said regeneration. zone by contact with an oxygen-containing gas, elutriating catalyst fines from the regenerated catalyst by disengaging spent regeneration gases therefrom through a variable area of a dense compact mass of said catalyst, subsequently treating the regenerated catalyst with a hydrogen-containing gas to remove residual sulfur from said catalyst, and passing the thus treated regenerated catalyst back into said conversion zone for repassage therethrough.l

3. A process according to claim 2 wherein said combinedstream of catalyst from said conversion zone is regenerated and returned to said conversion zone by the steps which comprise passing said catalyst from said conversion zone into a solids pressuring zone which communicates at its lower end with an elongated conveyanceregeneration zone, injecting a conveyance iiuid thereinto at a pressure' substantially above that of said conversion zoneV whereby the iuid ows therefrom through said conveyance-regeneration zone at a rate sucient to overcome opposing forces of gravity and friction acting on said catalyst therein and conveys said catalyst upwardly therethrough as Aa continuous dense packed mass of catalyst solids having substantially the same bulk density of said catalyst when at rest, applying a force against the mass of catalyst emerging from said conveyance-regeneration zone vto maintain the dense packed condition of said catalyst therein, and maintaining a concentration of oxygen in the conveyance tluid owing through said conveyance-regeneration zone whereby the catalyst is regenerated during conveyance.

4. A process according to claim 3 wherein the emerging catalyst from said conveyance-regeneration zone discharges centrally at a point communicating with the lower open ends of a plurality of circularly disposed eluhiation zones of pie-shaped cross section, in combination with the steps of disengaging said conveyance iluid from the emerging mass of granular catalyst through the external area of 'said' mass of catalyst in at least one of said elutriation zones so that catalyst lines are suspended from saidmass,`control1ing the number of said plurality of elutriation zones in which said conveyance uid is disengaged to'vary the fluid disengaging area and the disengaging velocity to control the degree of elutriation, and withdrawing the conveyance iiuid and suspended catalyst nes from said elutriation zone.

5. A method according to claim 2 in combination with the step of'controlling the relative flow rates of said first and second catalyst streams removed from said desulfurization-and'reforming zone respectively and just prior to the combination of said streams in said conversion zone.

6. A process vfor simultaneous conversion of gas-oil and naphtha hydrocarbon fractions in the presence of a recirculating stream ,of cobalt molybdate hydrocarbon conversion catalystanalyzing between about 2% and 10% by weght'of CoO`and between about 5% and 30% by weight of M003 which comprises recirculating said catalyst through a hydrocarbon conversion zone containing a desulfurization and a reforming zone, and through a catalyst `regeneration zone, dividing the regenerated catalyst into a iirst and a second catalyst stream prior to passage of said catalyst through said conversion zone, passing said first catalyst stream into and directly through said desulfurization zone as a downwardly moving bed by gravity in direct contact with gas-oil and naphtha vapors passing therethrough and then through said reforming zone in indirect heat exchange relation thereto and out of contact with naphtha Ivapors therein, passing said second catalyst stream as a downwardly moving bed by gravity through-saidA desulfurization zone outV of con# tact with said gas-oil and naphtha vapors and in indirect heat exchange relation thereto and then into and directly through said reforming zone in direct contact with said naphtha vapors therein, subsequently combining said first and second catalyst streams prior to removal from said hydrocarbon conversion zone, maintaining said desulfurization zone at a hydrocarbon desulfurization temperature of from about 575 F. to 900 F. and at a superatmospheric pressure of from about 50 p.s.i. to about 5000 p.s.i., maintaining said reforming zone at a hydrocarbon reforming temperature of from about 800 F. to 1000 F. and at substantially the same superatmospheric pressure, passing a naphtha hydrocarbon fraction and from about 500 and 10,000 s.c.f. of hydrogen per barrel of naphtha first through the combined first and second catalyst streams to strip residual gas-oil hydrocarbons therefrom and then through said reforming zone in contact with said second catalyst stream, combining the thus treated naphtha with a gas-oil hydrocarbon fraction, passing the naphtha, gas-oil, and hydrogen mixture thus formed into and through said desulfurization zone in contact with said first catalyst stream, removing an effluent therefrom, cooling and partially condensing said efiiuent, separating an uncondensed hydrogen-rich gas, recirculating at least part thereof through said conversion zone, removing the combined catalyst stream from said conversion Zone, regenerating :said catalyst in said regeneration zone by contact with an oxygen-containing gas, elutriating catalyst fines from a dense compact mass of the regenerated catalyst by disengaging spent regeneration gases therefrom through a variable surface area of said dense catalyst, -subsequently treating the regenerated catalyst with a hydrogen-containing gas to remove residual sulfur from said catalyst, and passing the thus treated regenerated catalyst back into said conversion zone for repassage therethrough.

7. An apparatus for the contacting of two fluid streams with a recirculating stream of granular solid contact material which comprises an elongated vertical contact column adapted to the downward passage by gravity of a moving bed of solid granular contact material and provided at successively lower levels therein with a solids hopper and seal section, a first treating section, a second treating section, a third treating and stripping section, a solids inlet conduit opening into the top of said column, an inlet conduit for a first solids stream opening from said hopper into the top of said first treating section, at least one elongated conduit for a second solids stream opening from said hopper and extending entirely through said first treating section into the top of said second treating section, a solids outlet conduit therefrom opening into said third treating and stripping section, at least one elongated conduit for said first solids stream opening from the bottom of said first treating section and eX- tending entirely through said second treating section and into said third treating and stripping section, means disposed between said second and third sections for controlling the relative flow rates of said first and second solids streams, a solids outlet conduit opening from the bottom of said column, a solids conveyance-regenerator conduit communicating at its lower end with said solids outlet, an upper solids-receiving vessel communicating with the top of said conveyance-regenerator conduit and connected in solids delivery relation to the top of said column, means for depressuring a fiuid through said conveyance-regenerator conduit at a rate sufiicient to convey said solids, means for introducing an oxygen-containing gas into said fluid, means within said solids-receiving vessel to apply a force against solids emerging from said conveyance-regenerator conduit to maintain solids therein during conveyance at substantially their static bulk density, said solids-receiving vessel being provided in its upper end with (l) a plurality of angularly disposed baffles intersecting along the vertical axis of said vessel and sealed at their outer and upper edges against the inner Walls of said vessel and having their lower edges submerged in emerging solids defining a plurality of sealed individual elutriation chambers of pieshaped cross section therein, and (2) controllable fiuid outlet means to remove elutriation fluid from at least one of said elutriation chambers whereby said fiuid is disengaged from said emerging solids through the surface thereof in each of said individual chambers to elutriate solids fines therefrom, means for introducing one fluid stream for passage upwardly through said third treating and stripping section and said second treating section in succession, means for introducing another fluid stream for upward passage through said first treating section, efiiuent outlet conduit means for removing a fluid effluent at the top thereof, cooling and condensing means communicating with said effiuent outlet means and communicating with vapor-liquid separator means, and a vapor recycle conduit and pump means communicating from said separator means and opening into the bottom of said column through a vapor heating means.

8. A method for transferring granular solids and separating solids fines therefrom which comprises introducing said solids and a conveyance fluid at relatively high pressure into an elongated conveyance zone, maintaining the outlet of sai-d zone at a relatively low pressure so as to maintain a flow of said conveyance fluid therethrough at a rate suicient to generate a pressure difterential which overcomes forces of gravity and friction opposing solids movement therein, discharging the solids from said conveyance zone upwardly at a central point in a solids-receiving zone, applying a fluid-impervious flow-restricting force against the discharging solids at a point slightly above the outlet of said conveyance zone to (l) maintain said solids during conveyance as a dense moving mass in which the solids are substantially at their static bulk density, and (2) to deflect said solids as a compact mass flowing downwardly and transversely from said flow-restricting force and submerging the outlet of said conveyance zone, disengaging the conveyance fiuid from beneath the surface of the discharged compact mass of solids in said solids receiving zone, controlling the area of said solids mass therein through which said fluid is disengaged to control elutriation of solids fines therefrom by the conveyance fiuid, removing disengaged fluid and solids fines from said solidsreceiving zone, and withdrawing solids of reduced fines content therefrom.

9. An apparatus for the transfer and elutriation of granular solids which comprises an elongated conveyance conduit, means for introducing granular solids to be transferred and a conveyance fiuid under pressure into the inlet opening of said conduit, a solids-receiving chamber surrounding the outlet opening of -said conveyance conduit, a plurality of substantially vertical angularly disposed bafiies intersecting substantially along the vertical axis of said chamber and sealed at their outer and upper edges against the inner Walls of said solids-receiving chamber providing a plurality of elutriation chambers therein having pie-shaped cross sections, said conveyance conduit communicating therewith at a point substantially on said axis and above the lower ends of said baffles, a transverse baflie means above and spaced apart from said outlet opening against which a mass of solids discharges from said outlet to maintain said solids in said conduit at their static bulk density, said mass of solids filling the lower part of said solids-receiving chamber to a level above the bottom of said vertical angularly disposed bafiies, an outlet means for solids opening from the bottom of said solids-receiving chamber, means to control the rate of solids removal therefrom, and a conveyance fiuid outlet opening from the upper part of said solids-receiving chamber and controllably adaptable to withdraw conveyance iiuid from at least one of said elutriation chambers so as to disengage said conveyance fluid from the discharging solids mass through the exposed surface area of said mass only in said elutiiation chambers from which iluid is Withdrawn whereby a controlled elutriation of solids nes from said solids mass is obtained.

References Cited in the le of this patent UNITED STATES PATENTS Davis Apr. 23, 1918 Meston Aug. 31, 1937 Belchetz Aug, 19, 1941 Penisten Aug. 25, 1942 Byrns Jan. 22, 1946 Giuliani Oct. 15, 1946 Simpson Apr. 6, 1948 Crowley Oct. 1, 1948 20 Leffer Ian. 25, 1949 Crowley Apr. 5, 1949 Crowley Dec. 6, 1949 Bonnell Jan. 17, 1950 Evans Feb. 27, 1951 McKinney July 3, 1951 Caldwell Apr. 29, 1952 Eastwood Aug. 12,1952 Dartv Nov. 10, 1953 Bills July 20, 1954 Hicks May 29, 1956 Eastwood May 7, 1957 OTHER REFERENCES New Lift Technique Weber, Oil and Gas Journal, Aug. 11, 1952, page 75.

Claims (3)

1. A PROCESS FOR THE SIMULTANEOUS CONTACTING OF TWO FLUID STREAMS OF SUBSTANTIALLY DIFFERENT PHYSICAL PROPERTIES WITH MOVING BEDS OF GRANULAR SOLID CONTACT MATERIAL IN A SINGLE CONVERSATION ZONE WHICH COMPRISES DIVIDING A STREAM OF GRANULAR SOLID CONTACT MATERIAL INTO A FIRST AND A SECOND STREAM AT THE TOP OF SAID CONVERSION ZONE, PASSING THE FIRST SOLIDS STREAM DOWNWARDLY AS A MOVING BED THROUGH A FIRST TREATING ZONE MAINTAINED AT A RELATIVELY LOW CONTACTING TEMPERATURE AND IN DIRECT CONTACT WITH FLUIDS PASSING THERETHROUGH, THEN PASSING SAID FIRST SOLIDS STREAM DOWNWARDLY THEREFROM THROUGH AND IN INDIRECT HEAT EXCHANGE RELATION WITH A SUBJACENT SECND TREATING ZONE MAINTAINED AT A RELATIVELY HIGH CONTACTING TEMPRATURE AND OUT OF DIRECT CONTACT WITH FLUIDS PASSING THERETHROUGH WHEREBY SAID SOLIDS STREAM IS INDIRECTLY HEATED, SIMULTANEOUSLY PASSING SAID SECOND SOLIDS STREAM DOWNWARDLY AS A MOVING BED THROUGH AND IN INDIRECT HEAT EXCHANGE REALTION WITH SAID FIRST TREATING ZONE AND OUT OF CONTACT WITH FLUIDS PASSING THERETHROUGH, THEN PASSING SAID SECOND SOLIDS STREAM THEREFROM DOWNWARDLY THROUGH AND IN DIRECT CONTACT WITH FLUIDS PASSING THROUGH SAID SECOND TREATING ZONE, COMBINING SAID FIRST AND SECOND SOLIDS STREAMS IN AND PASSING THEM TOGETHER THROUGH A THIRD TREATING AND SOLIDS STRIPPING ZONE FURTHER STRIPPING THE

7. AN APPPARATUS FOR THE CONTACTING OF TWO FLUID STREAMS WITH A RECIRCULATING STREAM OF GRANULAR SOLID CONTACT MATERIAL WHICH COMPRISES AN ELONGATED VERTICAL CONTACT COLUMN ADAPTED TO THE DOWNWARD PASSAGE BY GRAVITY OF A MOVING BED OF SOLID GRANULAR CONTACT MATERIAL AND PROVIDED AT SUCCESSIVELY LOWER LEVELS THEREIN WITH A SOLIDS HOPPER AND SEAL SECTION, A FIRST TREATING SECTION, A SECOND TREATING SECTION, A THIRD TREATING AND STRIPPING SECTION, A SOLIDS INLET CONDUIT OPENING INTO THE TOP OF SAID COLUMN, AN INLET CONDUIT FOR A FIRST SOLIDS STREAM OPENING FROM SAID HOPPER INTO THE TOP OF SAID FIRST TREATING SECTION, AT LEAST ONE ELONGATED CNDUIT FOR A SECOND SOLIDS STREAM OPENING FROM SAID HOPPER AND EXTENDING ENTIRELY THROUGH SAID FIRST TREATING SECTION INTO THE TOP OF SAID SECOND TREATING SECTON, A SOLIDS OUTLET CNDUIT THEREFROM OPENING INTO SAID THIRD TREATING AND STRIPPING SECTION, AT LEAST ONE ELONGATED CONDUIT FOR SAID FIRST SOLIDS STREAM OPENING FROM THE BOTTOM OF SAID FIRST TREATING SECTION AND EXTENDING ENTIRELY THROUGH SAID SECOND TREATING SECTION AND INTO SAID THIRD TREATING AND STRIPPING SECTION, MEANS DISPOSED BETWEEN SAID SECOND AND THIRD SECTIONS FOR CONTROLLING THE RELATIVE FLOW RATES OF SAID FIRST AND SECOND SOLIDS STREAMS, A SOLIDS OUTLET CONDUIT OPENING FROM THE BOTTOM OF SAID COLUMN, A SOLIDS CONVEYANCE-REGENERATOR CONDUIT COMMUNICATING AT ITS LOWER END WITH SAID SOLIDS OUTLET, AN UPPER SOLIDS-RECEIVING VESSEL COMMUNICATING WITH THE TOP OF SAID CONVEYANCE-REGENERATOR CONDUIT AND CONNECTED IN SOLIDS DELIVERY RELATION TO THE TOP OF SAID COLUMN, MENAS FOR DEPRESSURING A FLUID THROUGH SAID CONVEYANCE-REGENERATOR CONDUIT AT A RATE SUFFICIENT TO CONVEY SAID SOLIDS, MEANS FOR INTRODUCING AN OXYGEN-CONTAINING GAS INTO SAID FLUID, MEANS WITHIN SAID SOLIDS-RECEIVING VESSEL TO APPLY A FORCE AGAINST SOLIDS EMERGING FROM SAID CONVEYANCE-REGENERATOR CONDUIT TO MAINTAIN SOLIDS THEREIN DURING CONVEYANCE AT SUBSTANTIALLY THEIR STATIC BULK DENSITY, SAID SOLIDS-RECEIVING VESSEL BEING PROVIDED IN ITS UPPER END WITH (1) A PLURALITY OF ANGULARLY DISPOSED BAFFLES INTERSECTING ALONT THE VERTICAL AXIS OF SAID VESSEL AND SEALED AT THEIR OUTER AND UPPER EDGES AGAINST THE INNER WALLS OF SAID VESSEL AND HAVING THEIR LOWER EDGES SUBMERGED IN EMERGING SOLIDS DEFINING A PLURALITY OF SEALED INDIVIDUAL ELUTRIATION CHAMBERS OF PIESHAPED CROSS SECTION THEREIN, AND (2) CONTROLLABLE FLUID OUTLET MEANS TO REMOVE ELUTRIATION FLUID FROM AT LEAST ONE OF SAID ELUTRIATION CHAMBERS WHEREBY SAID FLUID IS DISENGAGED FROM SAID EMERGING SOLIDS THROUGH THE SURFACE THEREOF IN EACH OF SAID INDIVIDUAL CHAMBERS TO ELUTRIATE SOLIDS FINES THEREFROM, MEANS FOR INTRODUCING ONE FLUID STREAM FOR PASSAGE UPWARDLY THROUG SAID THIRD TREATING AND STRIPPING SECTION AND SAID SECOND TREATING SECTION IN SECCESSION, MEANS FOR INTRODUCING ANOTHER FLUID STREAM FOR UPWARD PASSAGE THROUGH SAID FIRST TREATING SECTION, EFFUENT OUTLET CONDUIT MEANS FOR REMOVING A FLUID STREAM AT THE TOP THEREOF, COOLING AND CONDENSING MEANS COMMUNICATING WITH SAID EFFUENT OUTLET MEANS AND COMMUNICATING WITH VAPOR-LIQUID SEPARATOR MEANS, AND A VAPOR RECYCLE CONDUIT AND PUMP MEANS COMMUNICATING FROM SAID SEPARATOR MEANS AND OPENING INTO THE BOTTOM OF SAID COLUMN THROUGH A VAPOR HEATING MEANS.

8. A METHOD FOR TRANSFERRING GRANULAR SOLIDS AND SEPARATING SOLIDS FINES THEREFROM WHICH COMPRISES INTRODUCING SAID SOLIDS AND A CONVEYANCE FLUID AT RELATIVELY HIGH PRESSURE INTO AN ELONGATED CONVEYANCE ZONE, MAINTAINING THE OUTLET OF SAID ZONE AT A RELATIVELY LOW PRESSURE SO AS TO MAINTAIN A FLOW OF SAID CONVEYANCE FLUD THERETHROUGH AT A RATE SUFFICIENT TO GENERATE A PRESSURE DIFFERENTIAL WHICH OVERCOMES FORCES OF GRAVITY AND FRICTION OPPOSING SOLIDS MOVEMENT THEREIN, DISCHARGING THE SOLIDS FROM SAID CONVEYANCE ZONE UPWARDLY AT A CENTRAL POINT IN A SOLIDS-RECEIVING ZONE, APPLYING A FLUID-IMPERVIOUS FLOW-RESTRICTING FORCE AGAINST THE DISCHARGING SOLIDS AT A POINT SLIGHTLY ABOVE THE OUTLET OF SAID CONVEYANCE ZONE TO (1) MAINTAIN SAID SOLIDS DURING CONVEYANCE AS A DENSE MOVING MASS IN WHICH THE SOLIDS ARE SUBSTANTIALLY AT THEIR STATIC BULK DENSITY, AND (2) TO DEFLECT SAID SOLIDS AS A COMPACT MASS FLOWING DOWNWARDLY AND TRANSVERSELY FROM SAID FLOW-RESTRICTING FORCE AND SUBMERGING THE OUTLET OF SAID CONVEYANCE ZONE, DISENGAGING THE CONVEYANCE FLUID FROM BENEATH THE SURFACE OF THE DISCHARGED COMPACT MASS OF SOLIDS IN SAID SOLIDS RECEIVING ZONE, CONTROLLING THE AREA OF SAID SOLIDS MASS THEREIN THROUGH WHICH SAID FLUID IS DISENGAGED TO CONTROL ELUTRIATION OF SOLIDS FINES THEREFROM BY THE CONVEYANCE FLUID, REMOVING DISENGAGED FLUID AND SOLIDS FINES FROM SAID SOLIDSRECEIVING ZONE, AND WITHDRAWING SOLIDS OF REDUCED FINES CONTENT THEREFROM.

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