US2592403A - Method of preparing hydrocarbon feed stocks containing asphaltic material for catalytic cracking - Google Patents

Method of preparing hydrocarbon feed stocks containing asphaltic material for catalytic cracking Download PDF

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US2592403A
US2592403A US53726A US5372648A US2592403A US 2592403 A US2592403 A US 2592403A US 53726 A US53726 A US 53726A US 5372648 A US5372648 A US 5372648A US 2592403 A US2592403 A US 2592403A
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contact material
conversion
chamber
conduit
constituents
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US53726A
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Louis P Evans
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ExxonMobil Oil Corp
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Socony Vacuum Oil Co Inc
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    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G11/00Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G11/14Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts
    • C10G11/16Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts according to the "moving bed" method

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  • This invention pertains to a process for conmost readily available are high boiling crudes in which the oily constituents boil so high as to prevent their separation from asphaltic constituents by distillation processes without subjecting version of high boiling hydrocarbons in the 5 them to temperatures at which undesirable presence of a particle-form contact mass matethermal cracking and excessive coking occur.
  • rial. This invention deals particularly with a As a result in order to use such. high boiling process for conversion of high boiling hydrocarstocks at all, it is necessary first to subject them bon fractions which contain varying amounts of to a prediminar thermal'coking step to provide asphaltic constituents. some lower boiling oily fractions for a subsequent Such conversion processes may involve treatcatalytic cracking operation.
  • By-products from ing, reforming, polymerization, oxidation, desulthe coking process are a heavy liquid out which phurization, cracking, etc., of the hydrocarbons may contain a substantial amount of oily conto form any of a number of products.
  • a parstituents as well as asphaltic constituents and ticularly important process is the catalytic a very large amount of petroleum coke, the discracking conversion of hydrocarbons, it being posal of which often creates a serious refinery well known, for example that hydrocarbon fracproblem. tions boiling above the gasoline boiling range A.
  • Another object is the provision of a practical method for hydrocarbon conversion which permits the catalytic conversion, without excessive coke formation, of the high boiling oily constituents present in high boiling petroleum residua.
  • Another object is the provision of a process for catalytic conversion of hydrocarbons which is capable, without excessive coke formation of handling charging stocks boiling over a wide range of temperatures including very heavy constituents heretofore rejected as tar separator bottoms.
  • Another object of this invention is the provision of a new method for the catalytic conversion of the oily constituents of high boiling liquid charging stocks which cannot be vaporized without cracking or coking.
  • the process of this invention in its preferred form is one wherein the asphalt bearing feed stock is contacted under suitable sorption conditions with a particle-form, porous inorganic oxide gel contact material which is characterized by a pore structure in which the percentage macropores is relatively low and the percentage of smaller pores is large and which preferably consists substan tially of particles of 30 mesh size and larger size.
  • a particle-form, porous inorganic oxide gel contact material which is characterized by a pore structure in which the percentage macropores is relatively low and the percentage of smaller pores is large and which preferably consists substan tially of particles of 30 mesh size and larger size.
  • the unsorbed asphaltic constituents are separated from the contact material bearing sorbed oily constituents and the contact material is then passed through a conversion zone in admixture with a sufficient amount of hot regenthe process of this invention is to some extent dependent upon the variables involved in any particular application of the process. These important variables are time of contact between the erated contact material of the same type to heat 5 liquid asphalt bearing charge and the sorbent in it to a temperature suitable for the conversion the sorption zone, temperature in the sorption of the sorbed oily constituents to lower boling hyzone, viscosity of the liquid charge, and to a lesser drocarbon products.
  • the gaseOus hydrocarbon extent the ratio of liquid oil to sorbent charged products are separated from the spent contact to the sorption zone.
  • an inorganic oxide gel having a substantially uniform porosity of low macropore volume with an average pore diameter not exceeding about 125 angstrom units and a particle size preferably not smaller than about 30 mesh for most operations, have the ability to sorb the oily constituents of a liquid hydrocarbon fraction while leaving substantially unsorbed the asphaltic constituents. Natural and treated clays and bauxites do not appear to have this property.
  • the macropore volume of the contact material employed in the present invention should be relatively low so that the pore volume is mostly that of micropores. In general, the volume of macropores, that is, those pores having radii larger than 100 angstrom units, should constitute less than about 30 percent of the total pore volume and preferably 10 percent or less.
  • the porosity of the gel particles employed in the process of this invention is of fundamental importance.
  • the degree of porosity is generally reflected in the bulk density of the gel composite used; the lower the. bulk density, the greater being the degree of porosity.
  • particles having bulk densities of between about 0.4 and 1.1 grams per cubic centimeter are preferred.
  • the bulk densities indicated oorrespond'to an'avera-ge pore diameter of between about 20 and. about 125, angstrom units.
  • the sorbent' used will have a bulk density between about 0.6 and about 0.8 gram per cubic centimeter.
  • Gel particles having a bulk density greater than about 0.8 have been found to have excellent selectivity: but poor sorbing capacity, while particleswith a bulk density less than about 0.6 have relatively poor selectivity. However, since the selectivity of the deasphalting process improved with a decrease in temperature, particles with a bulk density less than 0.6 would be satisfactoryfor deasphalting stocks which can be processed at low temperatures. 7
  • the degree of porosity of a synthetic inorganic oxide geluyill in general, depend on the conditions under whichit is prepared and allowed to set to gelation.
  • a particularly convenient method of preparing gel particles used in.the process of this invention is described in U. S... 2,384,946,'issued September 18, 1945; to Milton M. Marisic. It is there disclosed that spheroidal particles of inorganic oxide gel may be prepared by mixing an acidic stream with a stream of sodium silicate and allowing. the resulting so]. to be ejected from a nozzle into an oil column; where the gel sets in the form of bead-likespheroids; The resultinggel spheres; after washing, drying and tempering, were of a size varying between.
  • the gel beads so produced had a bulk density of betweenabout" 0.4 and about 1.1 and an average pore diameter of between about 20 and about125- angstrom: units- They proved to-be excellent selective sorbents for use in the processof this invention.
  • fragments or particles 'ha-ving z.
  • spheroidal particles are to be preferred, since attrition losses-are thenat a minimum and contaminationwith gel. fines of the asphaltbearing :stock is substantially eliminated.
  • siliceous gel particles will be used in theprocessof this invention, such assilica gel,. silica-alumina gel, .silica-zirconia gel, silicathoria gel andthelike.
  • Porous sorptive silica glasses having a. structure approaching that of a siliceous gel likewise are contemplated for use inithe. process described herein, it being necessary,v however, that the porous glass employed have an average-pore diameter less than about 125 angstrom units," and a macropore volume of less than about 30 per cent of the total pore volume.
  • Thesize of the porous glass particles must also be carefully controlled so as to obtain preferential sorption. of the oily constituents. Usually particles of less than 60 mesh size are undesirable.
  • other porous materials not of the inorganic oxide gel composition which have structures approaching that of a siliceous gel and are within the above specified pore' size and particlesize limits may be employed within the scope of this invention.
  • Typical of the porous glasses used are those described in U. 3. 2,106,744, issued February 1, 1938, to Hood et a1.
  • a silica-alkali-boric oxide glass of suitable com position is prepared by a fusion process. Heat treatment of this glassresults in separation of the glass into two phases; one phase is rich in alkali-boric oxide and is soluble in acids, while the other phase, which is insoluble in acid, consists of silica with a small amount of boric oxide. Extraction of this heat treated glass with acid results in a porous silica glass which can be employed as a porous absorbent separating medium in accordance with the present invention.
  • Other types of sorbents which possess the physical structure and/or the sorbtive characteristics of inorganic oxidegels may be employed within the scope of this invention.
  • FIG 1 is a schematic arrangement of the system'of this invention in which some of the apparatus is shown partially in section;
  • Figure 2 is a similar view of a modified arrangement
  • Figure 3 is a diagrammatic flow sketch of still another modified arrangement.
  • an asphaltic bearing petroleum feed stock of relatively broad boiling range containing a vaporiaable gas oil fraction as well as heavier oily and asphaltic constituents may be introduced through conduit I 0 to tubes in a furnace I I wherein it is preheated to. a suitable flash temperature within the range about 500-850 F.
  • the furnace i i may be of construction conventionally employed for this purpose.
  • the preheated fraction then passes through conduit l2 to tar separator it which may be a bafiled tower of conventional construction. If desired,steam may be introduced into separator 13 through conduit i511 to assist in the vaporization of the lighter constituents of that charge.
  • a vaporized fraction is withdrawn from the top of separator I3 and passed into the upper section of a vertical convertor I4 through conduit l5.
  • a liquid fraction bearing high boiling oily and asphaltic constituents passes from the bottom of tower I3 through conduit I6 and is pumped by pump lI through conduit I8 and exchanger l9 and cooler ll into a deasphalting vessel 20.
  • the deasphalting vessel is an elongated, vertical vessel which may be preferably of rectangular cross-sectional shape but which may be of other shape if desired.
  • a solid inlet conduit 21 connects into the top of the vessel 20 and a drain duct 22 connects into the bottom of said vessel.
  • a plurality of spaced heat transfer tubes 23 extend horizontally across the upper section of vessel 20 between an inlet header box 24 and an outlet header box 25. Cooling water under pressure may be pumped from a stream drum 26 by pump 21 into the inlet header box 24 via pipe 29. Hot water and steam may be returned to steam drum 26 via pipe 30. If desired, a heat exchange fluid other than steam may be employed. For example, a fused inorganic salt or low melting point fused metallic alloy may be circulated through tubes 23 and a suitable external cooler. Inverted troughs 3
  • a con tinuous perforated belt 35 which may be of screen construction, for example.
  • the belt passes over pulleys 3G and 31, the latter pulley being driven by means of motor 38.
  • the continuous belt is encased in a gas tight chamber 38, and a receiving chamber 45 is provided adjacent the discharge end of the belt to receive discharged contact material.
  • a drain pan 4! is positioned under the belt 35 near its charging end to receive liquid drainings.
  • Suitable spray devices or wash solvent distributors 42 and 43 are provided over the belt 35 along a latter portion of its path of travel to distribute washing solvent onto the contact material carried on the belt 35. Drain pans 44 and 45 are positioned below the portion of the belt which is under the distributors 42 and 43, respectively.
  • Liquid drainings containing the unsorbed asphaltic constituents of the feed stock are drained from pan 4i through conduit 47 into the receiver 48 from which it is discharged through conduit 49, pump 50 and conduit 5!. If desired, a portion of the drainings from receiver 48 may be recycled to the deasphalting chamber via conduit 52 from which they enter the chamber 20 through perforated pipes 53, closed on the ends thereof within the vessel. Fins 54 are provided along pipes 53 to provide liquid distribution spaces thereunder. Liquid drainings from pan 45 pass via conduit 55 into receiver 56 from which it passes via conduit 38, pump 59 and conduit 59 into the first distributing device 42.
  • Solvent for distributor 43 may enter from an outside source through conduit 6
  • solvent cycle oil may be withdrawn from a conventional conversion product fractionator 65 through conduit 66 from which it enters conduit 62. It will be noted that the arrangement described permits efiicient use of the solvent in that fresh washing solvent is sprayed onto the partially washed contact material just before the contact material is discharged from the perforated moving belt and the solvent employed for this final washing is recycled and used for the first stage of the contact material washing, being sprayed from distributor 42 onto the contact material on the belt 35 along an intermediate portion of its path of travel through chamber 39.
  • Spent washing solvent from pan 44 is drained via conduit ID to receiver II. Any entrained contact material fines may be removed from the bottom of receivers II and 56 through outlets 290 and 291 respectively.
  • the spent washing solvent containing asphaltic material may then be passed from receiver II via conduit 3?, pump 68 and conduit 69 to the upper section of the tar separator l3 wherein it serves as a reflux or quenching fluid.
  • the asphaltic constituents in the spent washing solvent are separated from the solvent in separator I3 so that the solvent may pass along with other vaporizable constituents to the conversion vessel 14. This type of operation is particularly attractive when a cycle gas oil out from fractionator 65 or a virgin gas oil-cut is employed as the washing solvent.
  • the spent solvent from receiver II may exist at a relatively low temperature it may be heated by exchange with tar separator bottoms in exchanger I8 to a suit able temperature for introduction into tow-er l3.
  • all or part of the washings from receiver Il may pass via conduits 53 and 72 to the inlet Ill to the heating furnace H so that it may be preheated and flashed in the tower I3 along with the charge stock.
  • the solvents employed are other than gas oil or kerosene, it may be desirable to remove them from the system at I3 and treat them separately for removal of asphaltic constituents.
  • the discharge duct 22 from the deasphalting chamber may be of rectangular cross-sectional shape, extending in a direction perpendicular to the drawing substantially the width of belt 35.
  • Suitable guard members may be provided within chamber 39 to prevent contact material from falling off opposite sides of the belt 35.
  • a slide valve 682 may be provided in duct 22 to permit control of the rate of material withdrawal from chamber 29. Any excess washing solvent which has failed to drain from the contact material by the time it is discharged from belt 35 may be purged from the contact material in receiving chamber M3 by the introduction of a suitable heated gas from conduit I4 into perforated distributor tubes '15 in chamber 40. The ends of tubes I5 within chamber 40 are closed.
  • the purging gas should preferably be inert to the reaction in the conversion vessel. Exemplary of suitable purging gases are nitrogen, flue gas and steam.
  • a discharge conduit I6 is provided for withdrawal of contact material from receiving chamber 40 to seal chamber 11.
  • a slide valve I8 which controls the fiow of contact material from seal chamber 16 into conduit 19 which in turn directs the contact material into the upper section of conversion vessel I4.
  • the conversion vessel I4 is a substantially vertical vessel of suitable cross-sectional shape provided with a solid inlet feed leg I30 extending upwardly from its top to a supply hopper and with a solid discharge'conduitBI at its lower-end.
  • Apartition 82 is supportedacross the upper-section of yessel I4 to define aseal chamber 83.
  • a conduit 84 depends centrally from partition 82 and terminates shortly therebelow.
  • a cylindrical baffle curtain 85 is supported by rods 86 centrally below the conduit 84.
  • a skirt 8'! of substantially-less cross-sectional area at its base than the curtain 85 extends downwardly from the lower end of conduit 83 and terminates just short of the lower end of curtain 85.
  • AcylindricalbaffleBE-having a conical shaped roof issupported by rods *I3I directly below the lower end of conduit'83.
  • the baffle 88 is of'smaller diameter-than skirt 8I'so as to leave anannular passage-89 for contactimaterial fiow from conduit 83.
  • a second annular passage 90 is provided for solid flow between'skirt 8? and curtain B5. Into this latter passage "contact material from conduit 19 is directed.
  • the two separate streams of contact material from passages 89 and 90 are permitted to merge at: the lower extremities 'of these passages and the merged streams pass into an inverted conical basin 9
  • the size and position of basin 9I with respect to curtain 85 is such as to prevent overflow of catalyst over the edges of the basin 9
  • the above described arrangement for mixing the two separate inlet, streams of particle-form contact material- is only one of a number of arrangements which maybe employed.
  • the orifices 93 which may preferably be adjustable, are set-at such a size as to permit contact material discharge from basin 9
  • the suradjusting system is preferable.
  • the rod Hill may be rotated by a motor II3 through shaft H4 and gears I45. As the surface level of the column changes along the rod I 00, the power required to drive the electricmotor II 3 will vary.
  • a suitable instrument I49 actuated by the change in power-requirements for motor II3 will in turn actuate a motor IM to drive valve"99 in such a manner as to compensate any change in 'the'contact material column surface level at I42.
  • the gel-type contact material serves the dual function of a sorbent inthe deasphalting operation and as a catalyst for the conversion of the sorbed oily constituents ,inthe conversion zone.
  • a vertical regeneration vessel II5 having a solid inlet H6 at its upperendand a solid outlet I'II bearing 'valve H3 at its lower. end.
  • a suitable combustion supporting gas may be admitted to vessel I I5 from manifold I I9 through a plurality of vertically spaced gas inletpipes I20. Gas may be withdrawn from the vessel I'I4 through aplurality of spaced pipes I2I whichare vertically spaced from the inlet pipes in sucha, manneras to divide the vessel into a series of superposed burning stageseach having. separate spaced apart Theoutlet pipes I2 I-, all connect into a common outlet duct I24.
  • a plurality of cooling stages are provided alternating with the burning stages each cooling stage having a cooling fluid inlet "I 22 and'outlet I23. Cooling tubes may be provided within each cooling stage communicating with the inlet I22 and outlet I23.
  • a final cooling stage I provided withcooling fiuidinlet I25 and: outlet" I26 is providedb'elow the lastburning stage.
  • a conveyorI21 is provided to transfer contact material from convertor I4 to regenerator H5 and a conveyor I28 is provided to transfer contact material from regenerator H5 to supply-hopper 80.
  • conveyors may be of conventional constructiongadapted to transfer particle-form contact materialat elevated temperatures without excessive attrition; as an example, continuous bucket elevators are satisfactory.
  • the heavy liquid fraction from a separator I3 after being adjusted to a suitable inlet temperature by exchanger I9 and cooler I5I is sprayed bymeans of perforated tubes 32, which connect into inlet conduit I8, into the column of inorganic oxide gel particles in the deasphalting chamber 20.
  • Hot freshly regenerated gel-type contact material is supplied into the upper end of chamber 20 from supply hopper 80 via conduit '2I at a rate controlled by valve I52.
  • the hot contact material is cooled to a suitable temperature for the deasphalting operation by means of cooling tubes 23.
  • Hot water under pressure may be circulated through the tubes 23 by means of pump 21 to remove heat from the contact material.
  • Low pressure steam generated may be withdrawn from the steam drum 26 through pipe I54.
  • the temperature at which the deasphalting operation in chamber 20 is conducted may vary over a wide range, depending upon the properties of the liquid treated.
  • the temperature should be high enough to give the oil sufficient fluidity to permit rapid sorption of the oily constituents but low enough to permit the contact material to function selectively.
  • the maximum temperature maintained in the sorption zone is dependent on the viscosity of the stock being treated.
  • the sorption of oily constituents becomes less selective as the viscosity decreases.
  • the desirable sorption temperature has been found to vary from below room temperature to about 500 F. depending on the liquid fraction treated.
  • the temperature of the liquid introduced through tubes 32 and the contact material passing into the sorption zone below the cooling tubes 23 should be controlled to provide the desired sorption temperature
  • the contact material should not be admitted to contact with the asphalt bearing liquid fraction at temperatures at which substantial thermal coking of the liquid fraction would take place. In general this means that the contact material should be cooled at least below about 750 F. before being permitted to contact the liquid charge.
  • the liquid charged from tubes 22 percolates downwardly through the column of downwardly moving contact material in the chamber 20.
  • the residence time of the contact material within the chamber 20 may vary from about 1 to hours. depending upon the liquid fraction involved, the temperature and the ratio of the contact material to the liquid charge. In many operations it is desirable to control the residence time of the contact material in chamber 20 by means of valve I02 such as will permit substantial saturation of the contact material with sorbed oily constituents.
  • the ratio of contact material to liquid charge to the deasphalting chamber may vary from about 0.5 to 20 parts by weight of contact material per part of liquid asphalt bearing charge and preferably from about 2 to 6 parts of contact material per part of liquid charge.
  • the gel-type contact material bearing oily constituents sorbed in its pores and the liquid asphaltic material which remains substantially unsorbed is directed from chamber 20 onto the perforated moving belt 35. During that portion of the belt travel directly over the pan II most of the asphaltic liquid is drained from the contact material and withdrawn via conduit 41 to receiver 48. In some operations it may be necessary to recycle a portion of the recovered liquid from receiver 48 to chamber 20 in order to insure substantially complete separation of oily constituents from the asphaltic constituents in the liquid fraction.
  • a suitable washing solvent is sprayed or poured onto the contact material by means of devices 42 and 43 in order to wash away asphaltic material which adheres to the outer surface of the con tact material particles.
  • the amount of solvent employed in the washing step may vary from about 0.25 to 2.0 volumes of solvent per volume of contact material depending upon the particular operation and. solvent involved and upon the viscosity of the unsorbed liquid.
  • the washed contact material is then purged or blown in receiving chamber by means of a suitable heated purge gas in order to remove from its outer surface any adhering liquid so as to thereby improve the fiowability of the contact material particles.
  • the contact material from washing chamber 39 may be partially preheated by passing the hot regenerated contact material charge to chamber 20, in indirect heat transfer relationship with the cooler washed contact material before the introduction of the regenerated contact material into the deasphalting chamber 20. It is also contemplated to be within the scope of this invention to charge the washed contact material directly into the reactor without an intermediate purging or heating step.
  • a mixing vessel adapted to handle the solid material and liquid as a slurry may be employed as the deasphalting chamber and after the proper residence time in the sorption zone the slurry may be treated in a continuous rotary type filter for separation of asphaltic liquid from the contact material particles and for washing of the particles.
  • the washing step may be eliminated and the asphaltic liquid adhering to the particles may be removed by purging and/or draining.
  • the washed and purged contact material bearing sorbed oily constituents then passes from chamber 40 downwardly through leg 16 into seal chamber TI wherein an inert gaseous pressure is maintained slightly above that in section I of convertor I4 by means of gas introduction through pipe IBI at a rate controlled by automatic diaphragm operated valve I62.
  • Contact material passes from chamber 11 at a rate controlled by slide valve I8 into conduit 19 by which it is directed into the mixing device in the upper section of convertor I4.
  • Hot regenerated contact material from hopper passes downwardly through the gravity feed leg I30 into the seal chamber 83 wherein an inert gaseous pressure is maintained slightly above the pressure in space IEO by means of gas introduced through pipe I65 at a rate controlled by diaphragm valve I68.
  • the gas introduced to both seal chambers I? and 83 may be steam, flue gas, nitrogen, etc.
  • the hot regenerated contact material passes downwardly from seal chamber 83 via conduit 84 into the mixing device.
  • the stream 89 of hot regenerated contact material mixes with the stream 90 of cooler contact material bearing sorbed oily constituents so as to heat the latter stream to a temperature suitable gasoline is the desired, product.
  • gaseous as employed herein in describing and in claiming this invention is intended in a broad sense as meaning material existing in the gaseous phase under the particular conditions of temperature and pressure involved regardless of the normal phase of such material under atmospheric conditions.
  • the gaseous products are disengaged from the column of contact material in the lower section of the conversion zone by means of.
  • mixed gaseous products from convertor I4 are Y directed through conduit I01 into a suitable fractionator B5.
  • Gasoline and lighter products are withdrawn from the top of fractionator 65 via conduit I68, a portion of this stream being condensed in cooler I66 and refluxed via conduit lit and a portion being withdrawn via conduit ill for further fractionation.
  • a light cycle stock boiling within the range about 450F. to 850 F. is withdrawn from fractionator 65 via conduit 56. if desired, be employed as the washing solvent and the remainder of this cycle stock is withdrawn through conduit I12 either to be recycled to furnace H or to be used for purposes out side of the system.
  • a heavy cycle stock is withdrawn as a product from the bottom of the fractionator 65 via conduit I13. In many operations it has been found desirable to recycle this heavy cycle stock either to furnace II or separator l3 in order that it may be ultimately converted to lower boiling products.
  • the operating conditions within the convertor M will vary depending upon the activity of the catalyst employed, the particular petroleum charge involved, the reaction involved and the products desired. In general it has been found desirable to maintain the pressures within a range varying from subatmospheric to about 200 pounds per square inch. Pressures of the order of 5 to 50 pounds per square inch gauge are preferred.
  • the temperature for the conversion for cracking operations may vary from about 800 F. to 1100 F., temperatures of the order of 850 F. to 1000 F. being preferred where Where non- A portion of this cycle stock may,
  • the ratio of contact material to hydrocarbon throughput may vary from about 1.0 to 40 parts by weight of contact material per part of hydrocarbon charge.
  • the ratio of fresh hot regenerated contact material introduced via conduit 84 to that bearing sorbed oily constituents and introduced via conduit l9 should be so controlled that the resulting temperature of the mixture is suitable for accomplishing the desired hydrocarbon conversion.
  • the exact ratio used may be varied somewhat by control of the temperature of the hot regenerated contact material supplied to hopper 83 and by control of the amount of preheat given the washed contact material from chamber 39. It has been found preferable to employ about 2 to 10 parts by weight of fresh hot regenerated contact material per part of the contact material bearing the oily constituents from the deasphalting operation.
  • the amount of hot contact material employed may be substantially reduced in man operations by directing the vaporized hydrocarbons from tar separator l3 through conduits l5 and 3 into heater 8 wherein it is heated to a temperature above the desired reaction temperature and then passed via conduits I and 15 to the convertor. If desired a lighter and more thermally stable hydrocarbon feed such as light gas oil, naphthas or even normally gaseous hydrocarbons may be introduced at 6 into the heater 8 and then introduced into the converter to supply part of the heat requirements therein.
  • a lighter and more thermally stable hydrocarbon feed such as light gas oil, naphthas or even normally gaseous hydrocarbons may be introduced at 6 into the heater 8 and then introduced into the converter to supply part of the heat requirements therein.
  • the spent contact material bearing carbonaceous contaminant deposited is purged substantially free or" vaporizable products by means of a suitable purge gas such as steam or flue gas introduced through. conduit H83, and the purged contact material is withdrawn from the convertor through conduit 8!.
  • a suitable purge gas such as steam or flue gas introduced through. conduit H83
  • the rate of contact material throughout is controlled by orifices 93 in basin 9! and the rate of withdrawal via conduit M is automatically controlled by valve 539 to maintain the level column surface level 142 within a relatively narrow constant range.
  • the spent contact material is conveyed by conveyor 52'? to the top of regenerator l l 5.
  • the contact material passes as a substantially compact column downwardly through regenerator H5 while being subjected to alternating stages of burning and cooling as described hereinabove.
  • the contact material In general during the regeneration the contact material should be maintained at a level suitable for rapid contaminant combustion but below a heat damaging level.
  • the heat damaging level is that level at which the contact material sufiers a permanent loss in its catalytic and/or sorptive eii'iciency and may vary fromabout 1150 F. to 1450 F. depending upon the particular inorganic oxide gel-type catalyst involved.
  • the temperature of the regenerated contact material may be adjusted to the level desired in hopper by mean-s of the cooling section provided below the lowermost burning stage.
  • the system described hereinabove is adapted particularly for handling original petroleum charge stocks of relatively broad boiling range which charge stocks contain vaporizable fractions as well as heavy liquid oil and asphalt fractions.
  • the method and apparatus of this invention is capable of handling not only such petroleum stocks of broad boiling range but also heavier residual stocks high in asphalt content and essentially stripped of vaporizable gas oil.
  • Figure 2 there is shown an arrangement particularly adapted for handling such heavier stocks.
  • Figure 2 also shows a modified arrangement for washing the contact material from the deasphalting zone and for introducing it into the conversion zone.
  • Like elements of the systems in Figures 1 and 2 bear like numbers and the description thereof given under Figure 1 may be applied to same elements in Figure 2.
  • high boiling residuum charge is introduced directly into the deasphalting chamber 20 via conduit I90 after being subjected to preliminary heating in exchanger [9] 'by means of the steam produced in cooling the hot regenerated catalyst supply for chamber 20 to a suitable temperature for the deasphalting operation.
  • the deasphalting chamber employed may, if desired, be substantially the same as that employed for the processing of tar separator bottoms.
  • the chamber 20, shown in Figure 2 is substantially the same as that shown in Figure 1 except for a modification in the solid and liquid mixing section.
  • a partition I93 is provided across the chamber 20 between the solid cooling and the sorption zones.
  • Conduits I94 depend from the partition I93 for flow of cooled contact material to the sorption zone.
  • the conduits provide a solid excluded space I95 into which liquid inlet headers I96 bearing spray nozzles I97 extend.
  • a star type discharge valve 203 which may extend a substantial distance horizontally in a direction perpendic-ular to the face of the drawing is provided on the discharge duct '22 from chamber 20.
  • the contact material and unsorbed asphaltic liquid are directed by duct 22 onto the moving foraminate belt I98 in drain chamber I99.
  • the chamber I99 differs from chamber 39 of Figure 1 in that it is deviated entirely to the draining operation wherein chamber 39 is devoted to both the draining and washing operation.
  • Drained liquid bearing asphalt constituents passes through the foraminate screen into pan 4
  • the contact material from which unsorbed asphaltic liquid has been drained falls off the discharge end of belt I98 into a column of washing solvent maintained in a baflled washing chamber 200.
  • the contact material falls through the column of liquid in chamber 200 in a zigzag path enforced by bafiies 20I and passes from the bottom of chamber 200 into the boot section of a bucket type elevator 203 which communicates with chamber 200.
  • the Washed contact material is picked up by buckets 204 which may have perforated bottoms so that the wash solvent may be drained from the contact material as it is transferred to the top of the elevator.
  • the elevator may be inclined rather than vertical or the buckets may be adequately shaped to prevent liquid draining from one bucket from falling into a bucket therebelow.
  • the contact material is discharged from elevator 203 via chute 205 into the hopper 206 wherein it may be subjected to a partial preheat by means of indirect heat transfer with a suitable heat exchange fluid passed through tubes 20?.
  • a suitable heating and purging gas may be introduced into hopper 205 through manifold 208 and perforated tubes 2139.
  • hot cycle oil may be withdrawn from product fractionator 65 via conduit 66 and pumped by pump 210 through conduit ZII into the inlet header box 2I2 supplying tubes 20'! in hopper 206.
  • the cycle oil thus serves to heat the contact material to a temperature of the order of about 400 F.- 700 F. and is in turn cooled to a suitable temperature for its use as a washing solvent.
  • the cooled cycle oil passes from outlet header box 2I3 into conduit 2I4 by which it is directed into the boot section of the elevator 203 at the desired level.
  • the cycle oil then passes from the boot section of the elevator 203 upwardly through the washing chamber 200 from which it is withdrawn through conduit 2I6 to receiver 2II. Any entrained undersized contact material is separated from the used washed oil in receiver 2 I I and withdrawn through outlet 2I8.
  • the used washing oil is pumped by pump 2 I9 via conduit 23!] through exchangers 220 and 22I into a separate fractionating tower 222 wherein the cycle oil is recovered from the asphaltic material.
  • the cycle oil may be withdrawn from the top of fractionator 222 via conduit 220 and condensed in exchanger 220.
  • a portion of the condensate is refluxed to tower 222 via conduits 221 and 228 and the remainder may be withdrawn from the system via conduits 221 and 229 or returned to the system via conduits 22'! and 66.
  • Heavy cycle stock from fractionator 05 may be passed via pipe I'i3 through exchanger Hi to supply heat to the wash cycle oil. Asphalt may be removed from fractionator 222 via conduit 23 I.
  • a suitable washing solvent such as a naphtha fraction may be introduced directly into the boot section of elevator 203 via conduit 235 instead of cycle oil from fractionator 65.
  • the used washing solvent may be sepa rated from asphaltic constituents in the same manner described for the cycle oil, and a substitute heat exchange fluid may replace the cycle oil in the tubes 201 in hopper 206.
  • the used washing solvent from receiver 2 I! may be passed through tubes 23 in the deasphalting chamber 20 as the cooling fluid in place of hot water. .becomeheated by the hot catalyst from conduit 17 The washing oil which has 2! may then be introduced into fractionator 222.
  • the residuum liquid charge may be introduced cold into the deasphalting chamber and the inlet contactimaterial may he adjusted to a .temperaturesufficient to heat the oil upon mixing therewith toa suitabletemperature for theideasphalting operation;
  • the spent Washing solvent from receiver 2 ll may be withdrawn via conduits 23B and 355i to-be incorporated as cutting stock in refinery fuel blends thereby eliminating the fractionator 222.
  • the washed and partiallyheatedcontact material from hopper 206, still bearing sorbed oily constituents may be passed-downwardly through a gravity feed leg 236 wherein it flows as a substantially compact column into the seal chambar 231.
  • a gaseous pressure slightly above that in zone I60 of convertor i4 is maintained in seal chamber 231 by introduction thereinto of a suitable inert seal gas via conduit 239 at a suitable rate controlled by diaphragm valve 2M and differential pressure control instrument 24L
  • the pressure maintained in seal zone 23'! and in seal zone 83, into which hot regenerated catalyst is supplied should be of the order of about onequarter to one pound per square inch above that in zone 55! of convertor M.
  • the contact material from seal zone 231 passes therefrom via conduit 244 at a. suitable rate controlled by slide valve 245 and is directed into the upper section of the curtained zone defined by cylindrical curtain 246.
  • the hot contact material stream from conduit 84 is caused to mix with the cooler contact material from conduit 264 by means of the baflie members Bl and 88, which are similar to the same members in Figure 1, working together with the cylindrical curtain 245 which directs the mixed contact material onto a conical bathe 248 supported by rods 249 at a level substantially below'the lower extremity of members 81 and B3.
  • a basin '250 which is of less diameter than vessel 24 but of greater diameter than the base of conical baflle 248 is supported by rods 25H below the baffle 248 so as to receive the contact material flow therefrom.
  • the relative height of the sides of the basin 250 and the lower extremity of curtain 24B are fixed in such relationship as that in the arrangement of Figure 2, the total rate of contact material flow through the convertor is controlled only by means of valve 255 on the reactor bottom outlet 8! so that continuity of solid column is maintained from the valve 255 up through the solid mixing device, while in the arrangement of Figure 1, the rate of solid flow is controlled by the orifices 35% in basin 9i and the contact material is caused to shower through a short vertical section of con vertor M before reaching the column surface.
  • the ing device and basin shown between partition 32 and the contact'material column surface may be eliminated and the mixing of the two contact
  • the number and material streams may be effected at the surface win the upper portion of the column itself.
  • a plurality of spaced pipes may extend down from partition 82 in the apparatus of Figure 2 to the column surface to deliver hot contact material onto the column.
  • a plurality branch conduits may extend down from the end of the conduit 244 to the surface of the column for delivery of the cooler contact material onto the column surface at a plurality of points distributed uniformly across the column area. If desired, these latter branch pipes may extend a short distance below the column surface.
  • the contact material from conduit 2 34 may be showered down through an upper vertical portion of the vessel onto the surface of the column while the hot contact material is delivered directly onto the column as described.
  • oil bearing contact material may be mixed batchwise in a single vessel with hot regenerated contact material and the mixture may be maintained substantially stationary in the vessel for the desired length of time, while the gaseous products are withdrawn from the vessel as formed.
  • a portion of the regenerated catalyst is further cooled and supplied to the deasphalting zone while the remaining portion is transferred hot to the upper section of the conversion zone to mix with and heat the oil bearing catalyst from the deasphalting apparatus. While it is the preferred form of this invention to mix fresh hot regenerated catalyst with the oil bearing catalyst from the deasphalting zone, nevertheless in the broader aspects of this invention it is contemplated that the hot catalyst which is mixed with the oil bearing cata lyst from the deasphalting operation may be hot partially regenerated catalyst or even used catalyst from the convertor discharge which has been heated and recycled to the seal zone 33. Such a modified arrangement is shown in Figure 3.
  • the asphalt bearing liquid charge is introduced via conduit are into deasphalting chamber 35 wherein it is contacted with inorganic oxide gel-type contact material particles which are introduced at a suitable temperature through duct 302.
  • the contact material and unsorbed asphalt containing liquid then pass into chamber 3553 wherein they are separated.
  • the contact material is then washed in chamber 304 with a suitable solvent introduced at 305 and withdrawn at 306.
  • the washed contact material is then transferred by conveyor 30! to hopper 308 from which it flows through a gravity feed leg 309 to seal chamber 3l0.
  • the contact material passes via conduit 31 I from seal chamber 310 to mixing chamber 3l2 wherein it is mixed with hot, at least partially spent contact material entering chamber 312 via conduit 313 from seal chamber 3
  • the mixed contact material passes at a suitable conversion temperature into the top of converter 3l5 via conduit 3l6.
  • Gaseous conversion products are withdrawn from the convertor via conduit 3 I! and spent contact material bearing a carbonaceous contaminant, after being purged by a suitable gas introduced into chamber 315 at 3I8, is withdrawn from the bottom of convertor 315 via conduit 319 at a rate controlled by valve 320.
  • a portion of the spent contact material is transferred via conveyor 321 to chute 322, feeding the reconditioner 323.
  • the contact material is heated to a suitable temperature for heating the oily constituent bearing contact material from hopper 308 to the desired conversion temperature.
  • the contact material heating in vessel 323 may be accomplished either by direct or indirect heat transfer with a suitable heated heat exchange fluid introduced at 324 and withdrawn at 325.
  • a suitable heated heat exchange fluid introduced at 324 and withdrawn at 325.
  • a mixture of gaseous fuel and air may be introduced at 324 to burn and thereby heat the contact material.
  • a combustion supporting gas may be introduced at 324 at a rate such as will promote the burning of just a sufiicient portion of the contaminant deposited on the contact material to heat to the contact material to the required temperature.
  • the contact material may be heated to the desired temperature level without overheating it to a heat damaging level and without the need for any cooling tubes within or after the chamber 323.
  • the hot contact material passing from chamber 323 through gravity feed leg 325 to seal chamber 314 is partially regenerated catalyst.
  • the remainder of the spent contact material from convertor 3l5 is transferred via conveyor 321 to chute 321, feeding to the regenerator 328 wherein it is substantially completely regenerated by means of air or oxygen, etc., introduced at 329 and withdrawn at 330.
  • a suitable cooling fluid may be introduced through conduit 33l to suitable heat transfer tubes (not shown) within the regenerator in order to control the contact material temperature below a heat damaging level during the contaminant burning.
  • the cooling fluid may be withdrawn from the heat transfer tubes via conduit 332.
  • the regenerated contact material passes from regenerator 328 to cooler 333 wherein it is cooled by means of a suitable cooling fluid introduced at 334 and withdrawn at 335.
  • the cooled contact material passes from cooler 333 via conduit 336 and is transferred by conveyor 331 to conduit 302 feeding the deasphalting chamber 30!.
  • An inert gas such as steam, may be supplied to seal chambers 3l0 and 3M through conduit 338 at a rate controlled by valve 339 sufficient to maintain an inert gaseous pressure in both seal chambers above the gaseous pressure in catalyst mixing chamber 312.
  • a vaporized hydrocarbon charge may also be introduced into the convertor through conduit 339.
  • the relative amounts of spent catalyst passing A. P. I. gravity 19.4 Pour point 45 F. Saybolt Universal viscosity at 210 F 167' seconds Conradsen carbon residue 9.4% by weight Sulfur 1.5% by weight Cleveland Open Cup flash 435 F. Cleveland Open Cup fire 505 F.
  • silica alumina spheroidal gel catalyst of about 40 pounds per cubic foot unpacked density and average particle size of 0.129 inch (4-10 mesh size Tyler), prepared by the method described in United States Patent 2,384,946, issued September 18, 1945, to Milton Marisic, in a ratio of about 290 parts of sorbent per 100 parts of residuum charge by weight and maintaining atmospheric pressure and a temperature of about 300 F. and residence time of about two hours in the continuous type deasphalting chamber, and recycling the unsorbed liquid until substantially all the oily constituents have been removed, oily constituents amounting to about .of the charge may be separated from the asphaltic constituents contained in the above residuum charge.
  • the catalyst bearing the sorbed oily constituents is washed with about one-half its weight of a light cycle oil, the residence time of the catalyst in the washing operation being limited to about 3 minutes.
  • the catalyst before charging to the reactor contained about 29% of its weight of sorbed oily constituents having the following properties: A. P. I. gravity23.9, Saybolt Universal viscosity at 210 F. 83.3, kinematic viscosity at F. 210, Conradsen carbon 1.75% weight.
  • the catalyst bearing sorbed oily constituents and existing at about 210 F. was mixed together with hot regenerated catalyst of similar type existing at about 1090 F. by flowing the two catalyt streams into a closed vessel and mixing the catalyst in the vessel.
  • the weight ratio of hot to cold catalyst mixed exclusive of oil was about 1.9 to one.
  • the vaporous reaction products were withdrawn from the top of the closed vessel as fast as formed and the mixed catalyst was maintained in the vessel for about 10 minutes before withdrawing it.
  • the estimated reaction temperature was about 960 F. and the pressure was substantially atmospheric.
  • the following conversion yields were obtained corrected to a no loss basis:
  • a process fOlf"C0liVlSi0Il"Of original-petrm leum stocks of broad boiling rangecontaining vaporizable fractions and heavy liquid oil and asphalt fractions at elevated temperatures in the presence of a moving contact'material which comprises, heating said petroleum.
  • asphalt hydrocarbons which undergo. cracking before being vaporized which comprises; heating said original petroleum .stock of broad boiling range to a temperature .atwhich a substantial fraction of said stockis vaporized but. below a temperature at which substantial thermal cracking of any of the constituents occurs, passing the heated petroleum stock into a flashing zone to separate the vaporized hydrocarbon "fraction from the non-vaporized liquid hydrocarbon fraction, subjecting said liquid fraction .toa deasphalting operation to separate the .asphalt constituents therefrom, delivering thedeasphalted liquid fraction into a. confinedconversion zone.
  • the method for conversion of wide boiling range petroleum charge stocks to lower boiling hydrocarbon products at controlled elevated temperatures in the presence of a particle-form contact material comprises: heating said charge to a temperature below that at which it will besubstantially thermally cracked to vaporize ,a portion thereof, passing the heated charge into a flashing zone to separate the va porized fraction from non-vaporized asphalt containing fraction, contacting the asphalt bearing liquid, fractionirom said flashing zone at a temperature below that at which said ction would be vaporized in a confined d zone with a particleeform inorganic o as 6 type contact material made up of particles greater than about 30 mesh size and characterized in that its total pore volume is limited to less than about 30 percent macro-pores, whereby oily constituents in said fraction are sorbed by said contact material and asphaltic constituents remain substantially...uns0rbed, draining unsorbed asphaltic constitutents from said contact material bearing sorbed oily constitutents, subjecting said contact material to controlled washing with a gas oil to wash it substantially free of
  • a continuous process for conversion of high boiling hydrocarbon charges to lower boiling gasoline containing products in the presence of a particle-form catalytic material which comprises: heating the hydrocarbon charge to a temperature within the range about 500 to 800 F., passing the heated charge into a tar separating zone to separate a liquid fraction bearing asphaltic constituents from vaporized material, contacting the separated liquid fraction at suitable temperatures below about 500 F.
  • the method for conversion of wide boiling range petroleum charge stocks to lower boiling hydrocarbon products at controlled elevated temperatures in the presence of a particle-form contact material comprises: heating said charge to a temperature below that at which it will be substantially thermally cracked to vaporize a portion thereof, passing the heated charge into a flashing zone to separate the vaporized fraction from non-vaporized asphalt containing fraction, withdrawing said non-vaporized fraction from said flashing zone and effecting separation of the asphalt material from the liquid non-asphaltic hydrocarbon constituents in said non-vaporized fraction, bringing the separated non-asphaltic hydrocarbons in the liquid phase into contact with a hot contact material whereby said liquid hydrocarbons are heated to a temperature suitable for conversion thereof to lower boiling gasiform hydrocarbons, also bringing the vaporized fraction from said flashing zone into contact with said hot contact material to efiect its conversion to lower boiling gasiform hydrocarbons and separating the mixed gasiform products from the vaporized and non-vaporized charges from said contact material.
  • a process for catalytic conversion of high boiling petroleum fractions to gasoline containing products comprising, preheating an asphalt containing petroleum fraction to a non-cracking temperature at which a portion of said fraction will vaporize and separating the vaporized portion from the non-vaporized asphalt containing portion in a separation zone, separating asphalt constituents from the non-vaporized portion in a separate zone and introducing the resulting deasphaltized liquid into a confined conversion zone in the liquid phase and below conversion temperature to become heated to a catalytic cracking temperature by means of a hot catalyst and to pass downwardly through a substantially compact column of said catalyst to efiect conversion to lower boiling gasiform gasoline containing products, simultaneously passing the vaporized portion from said separation zone into contact with said catalyst in said conversion zone to efiect its conversion to gasiform gasoline containing products, withdrawing the mixed gasiform products from said conversion zone, sepa 25 rately withdrawing the catalyst from said conversion zone and subjecting it to regeneration 'by burning contaminant deposits therefrom, whereby said catalyst is

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Description

April 8, 1952 1.. P. EVANS 2,592,403
METHOD OF PREPARING HYDROCARBON FEED STOCKS CONTAINING ASPHALTIC MATERIAL FOR CATALYTIC CRACKING Original Filed Sept. 2'7. 194'? 5 Sheets-Sheet l FIG.
HOPPEI? DEAJPHALTl/VG ran ER .5 6g 18 Fl (If 6 6 V OUT FINES REMVIL I 74/? JEFIRIToR 16 INVENTOR {7 001.)" Bird/VJ V M4 AGENT 0R ATTORNEY I April 8, 1952 L. P. EVANS METHOD OF PREPARING HYDROCARBON' FEED STOCKS CONTAINING ASPHALTIC MATERIAL. FOR CATALYTIC CRACKING Original Filed Sept. 27, 1947 5 Sheets-Sheet 2 p 8, 1952 L. P. EVANS 2,592,403
METHOD OF PREPARING HYDROCARBON FEED STOCKS CONTAINING ASPHALTIC MATERIAL FOR CATALYTIC CRACKING Original Filed Sept. 27, 1947 5 Sheets-Sheet 3 REGOIVD/TIONE'R 322 HOPPER 385325 34 307 X 308 '32 4 9 323 GOIWEYORS l 326 I ASPHALT A gzggg cam Eran .137 327 3,4 3/3 DEASPIIALTTI'IG 3/0 GIMME/s 3 mffi ilwm H.E.M. 30/- GUI, 3 2] LUE ans our m l I 330 I VAPOR/ZED CHARGE 35% GOgflTg/fI/G car/warm? REGE/VEIMTOR .WA swirls 333 l snseaus 011441551? I 335 PRODUCTS our aoouns *3/ 7 304- FL um 01/7 PURGE GAS IN SPENT WASH 600L iNG S01. VENT FL (/10 IN a l 32/ o- INVEN TOR.
336 LOU/5 P E VANS BY 337 o w a. 3
AT TOR/VEYOR AGE/VT Patented Apr. 8, 1952 METHOD OF PREPARING HYDROCARBON FEED STOCKS CONTAINING ASPHALTIC MATERIAL FOR CATALYTIC CRACKING Louis P. Evans, Woodbury, N. J., assignor to Socony-Vaouum Oil Company, Incorporated, a corporation of New York Original application September 27, 1947, Serial No. 776,471. Divided and this application tober 9, 1948, Serial No. 53,726
7 Claims. 1 This application is a division of my pending application Serial Number 776,471, filed September 27, 1947.
This invention pertains to a process for conmost readily available are high boiling crudes in which the oily constituents boil so high as to prevent their separation from asphaltic constituents by distillation processes without subjecting version of high boiling hydrocarbons in the 5 them to temperatures at which undesirable presence of a particle-form contact mass matethermal cracking and excessive coking occur. rial. This invention deals particularly with a As a result in order to use such. high boiling process for conversion of high boiling hydrocarstocks at all, it is necessary first to subject them bon fractions which contain varying amounts of to a prediminar thermal'coking step to provide asphaltic constituents. some lower boiling oily fractions for a subsequent Such conversion processes may involve treatcatalytic cracking operation. By-products from ing, reforming, polymerization, oxidation, desulthe coking process are a heavy liquid out which phurization, cracking, etc., of the hydrocarbons may contain a substantial amount of oily conto form any of a number of products. A parstituents as well as asphaltic constituents and ticularly important process is the catalytic a very large amount of petroleum coke, the discracking conversion of hydrocarbons, it being posal of which often creates a serious refinery well known, for example that hydrocarbon fracproblem. tions boiling above the gasoline boiling range A. major object of this invention is the promay be converted to lower boiling gasoline convision of a process for conversion of high boiltaining hydrocarbons upon being subjected to ing asphalt bearing hydrocarbon fractions which contact with a suitable solid porous catalyst at temperatures of the order of 800 F. and upwards and at pressures usually above atmospheric.
Heretofore such conversion processes have been limited to the conversion of relatively light, clean, substantially tar or asphalt free petroleum feed stocks because of the tendency of the asphalt containing stocks to cause the formation of excessive deposits of coky contaminants on the catalyst which deposits cannot be economically removed. In order to avoid, these heavy coke deposits which render the cracking process unfeasible, it has'been the wide refinery practice to subject some high boiling petroleum feed stocks (when available with a broad boiling range) to a preliminary tar separation step, separate an easily vaporizable fraction from a liquid fraction which bears the asphaltic constituents and to subject only the vaporizable fraction to catalytic cracking while discarding the liquid tar separator bottoms. Since this discarded fraction may be made up of a large proportion of valuable oily constituents and a smaller proportion of asphaltic constituents, it is obvious that a large quantity of otherwise acceptable catalytic cracking feed stock is lost and unavailable as such in the prior art tar'separator operation. When the crude residuum is not of such boiling range and does not contain substantial amounts of vaporizable gas oil, it has been considered in practice as being unsuitable as such for a cracking charge stock. The problem is becoming increasingly serious due'to the fact that relativelylow boiling petroleum crudes are becoming less plentiful and the crudes which are process avoids the above described difficulties of the prior art.
Another object is the provision of a practical method for hydrocarbon conversion which permits the catalytic conversion, without excessive coke formation, of the high boiling oily constituents present in high boiling petroleum residua.
Another object is the provision of a process for catalytic conversion of hydrocarbons which is capable, without excessive coke formation of handling charging stocks boiling over a wide range of temperatures including very heavy constituents heretofore rejected as tar separator bottoms.
Another object of this invention is the provision of a new method for the catalytic conversion of the oily constituents of high boiling liquid charging stocks which cannot be vaporized without cracking or coking.
These and other objects of this invention will become apparent from the following discussion.
The process of this invention in its preferred form is one wherein the asphalt bearing feed stock is contacted under suitable sorption conditions with a particle-form, porous inorganic oxide gel contact material which is characterized by a pore structure in which the percentage macropores is relatively low and the percentage of smaller pores is large and which preferably consists substan tially of particles of 30 mesh size and larger size. By this contacting the oily constituents of the feed stock are sorbed in the pores of the contact material and the asphaltic constituents remain unsorbed. The unsorbed asphaltic constituents are separated from the contact material bearing sorbed oily constituents and the contact material is then passed through a conversion zone in admixture with a sufficient amount of hot regenthe process of this invention is to some extent dependent upon the variables involved in any particular application of the process. These important variables are time of contact between the erated contact material of the same type to heat 5 liquid asphalt bearing charge and the sorbent in it to a temperature suitable for the conversion the sorption zone, temperature in the sorption of the sorbed oily constituents to lower boling hyzone, viscosity of the liquid charge, and to a lesser drocarbon products. The gaseOus hydrocarbon extent the ratio of liquid oil to sorbent charged products are separated from the spent contact to the sorption zone. Increasing time of contact material which may be then subjected to regenand increasing temperature result in a decrease eration. in the efiiciency of separation of asphaltic and It has long been known that when porous adoily constituents. Decreasin viscosity of the liqsorbents such as bauxites and natural and treated uid charge has the same effect. On the other clays are contacted with liquid petroleum frachand increasing temperature and decreasing vistions, the asphaltic constituents may be adsorbed cosity both result in more rapid sorption of the on the clay and thus removed from the oily conliquid oily constituents by the sorbent. If the stituents. Such a process is commercially emratio of sorbent to liquid charge is excessive some ployed for the decolorizing of mineral oils by loss in separation efficiency results. By proper percolation of the oils through clay type adsorbcontrol of these variables some latitude in the ents. The present process is the opposite of the average diameter of the sorbent employed may be so-called percolation and contact filtration procprovided. However, when the diameter of the esses for oil refining in that, by the present procparticles becomes too small, the sorbent preferess, it is the oily constituent and not the asentially adsorbs the asphaltic constituents from phaltic constituent which is sorbed by the contact the liquid charge in the same manner as well material. This fundamental difierence makes known oil filtering d ys. This is shown in Table possible the combination cracking process of this I below in which is tabulated the deasphalting invention and permits the elimination of the asresults obtained on mid-continent residuums usphalt materials without contamination of the ing a silica-alumina gel type sorbent having a catalyst thereby. It has been found that porous bulk density in the 4-8 mesh size range of about contact materials, having a structure correspond- 0.7
Table I Experiment Number 1 4 5 6 7 2 3 Charge Viscosity, S. U. V 116.9 116.9 81.8 81.8 81.8 81.8 340 Charge Ramsbottom Carbon 2. 3 2. 3 2. 3 2. 3 5.1 Mesh Size of Sorbent (Tyler) 4-8 3060 3060 -80 30-00 4-8 4-8 sorption Zone Contact Time 24 hrs 24 hrs 2min 2min 2hrs 72 hrs 4111's sorption Zone Temperature, F- 150 150 150 150 150 75 275 Weight Ratio of Sorbent to L uid Charge l 1 1 1 l 1 2.2 Properties of Oily Constituents Retained by Sorbent:
s. U. v. at 210 F. Sec 69.7 129.2 75.2 81.7 115.4 40.7 151 Ramsbottoin Carbon, percent 1. 8 2. 3 3.1 2. 4 Properties of Asphaltic Materials Washed from Sorbent:
s. U. v. at210 F. Sec 164 100.1 85.9 80.5 76.0 139.2 050 Ramsbottom Carbon, Percent 2. 4 2. 2 2.0 3. 5 6. 7
ing to that of an inorganic oxide gel having a substantially uniform porosity of low macropore volume with an average pore diameter not exceeding about 125 angstrom units and a particle size preferably not smaller than about 30 mesh for most operations, have the ability to sorb the oily constituents of a liquid hydrocarbon fraction while leaving substantially unsorbed the asphaltic constituents. Natural and treated clays and bauxites do not appear to have this property. The macropore volume of the contact material employed in the present invention should be relatively low so that the pore volume is mostly that of micropores. In general, the volume of macropores, that is, those pores having radii larger than 100 angstrom units, should constitute less than about 30 percent of the total pore volume and preferably 10 percent or less. The measurement of pore size and pore size distribution in various porous materials is discussed in detail by L. C. Drake and H. L. Ritter in Industrial and Engineering Chemistry, Analytical Edition, volume 17, pages 782-791, 1945. The methods described there were essentially those employed in determining the bulk densities, average pore diameters, and other pore measurements of the adsorbents employed in the present invention.
The size of the sorbent particles employed in It will be apparent from the above Table I that when the gel type sorbent particles were greater than 30 mesh size that even at relatively high temperatures and long contact periods the oily constituents of low viscosity and carbon residue were sorbed in the pores of the sorbent while the asphaltic constituents could be washed away with a suitable washing solvent, in this case benzol. On the other hand, in the case of sorbent particles ranging from 30-60 mesh size, when the contact period was 24 hours (Experiment 4) or even 2 hours (Experiment 7), the sorbent acted similar to a normal filtering clay and preferentially adsorbed the asphaltic constituents. But when the contact time was reduced to two minutes (Experiment 5), the 30-60 mesh sorbent exhibited a preference for the oily constituents over the asphaltic constituents. When the particle size was reduced below 60 mesh, the sorbent preferentially adsorbed the asphaltic constituents even at very low contact periods (Experiment 6).
The effect of contact time and temperature is shown in Table II below in which the deasphalting results on an East Texas residuum having an original Saybolt Universal viscosity of 512 seconds at 210 F. and a Ramsbottom carbon residue of 11.1. In this experiment a silica- In general it may be said that the. particle size of the sorbent material particularly in the case of inorganic oxide gel type sorbents should be less than about 60 mesh Tyler and preferably within the range about 0.022 to 1.0 inch average diameter. The best results may be obtained'by limiting the sorbents within the range 0.03 to 0.20 inch average diameter and of reasonably uniform size. It is pointed out, however, that by proper control of the variables discussed hereinabove and also of the average pore diameter of the sorbent, operation according to the method of this invention may be obtained on sorbent particles outside the size ranges given although the results will be less satisfactory. It is con-- templated that in its broader aspects this invention covers these latter operations as well as the operations within the specified preferred limits.
The porosity of the gel particles employed in the process of this inventionis of fundamental importance. The degree of porosity is generally reflected in the bulk density of the gel composite used; the lower the. bulk density, the greater being the degree of porosity. For the purposes of the present process, particles having bulk densities of between about 0.4 and 1.1 grams per cubic centimeter are preferred. The bulk densities indicated oorrespond'to an'avera-ge pore diameter of between about 20 and. about 125, angstrom units. Preferably, the sorbent' used will have a bulk density between about 0.6 and about 0.8 gram per cubic centimeter. Gel particles having a bulk density greater than about 0.8 have been found to have excellent selectivity: but poor sorbing capacity, while particleswith a bulk density less than about 0.6 have relatively poor selectivity. However, since the selectivity of the deasphalting process improved with a decrease in temperature, particles with a bulk density less than 0.6 would be satisfactoryfor deasphalting stocks which can be processed at low temperatures. 7
The degree of porosity of a synthetic inorganic oxide geluyill, in general, depend on the conditions under whichit is prepared and allowed to set to gelation. A particularly convenient method of preparing gel particles used in.the process of this invention is described in U. S... 2,384,946,'issued September 18, 1945; to Milton M. Marisic. It is there disclosed that spheroidal particles of inorganic oxide gel may be prepared by mixing an acidic stream with a stream of sodium silicate and allowing. the resulting so]. to be ejected from a nozzle into an oil column; where the gel sets in the form of bead-likespheroids; The resultinggel spheres; after washing, drying and tempering, were of a size varying between.
about 4 and about 20 mesh. The gel beads so produced had a bulk density of betweenabout" 0.4 and about 1.1 and an average pore diameter of between about 20 and about125- angstrom: units- They proved to-be excellent selective sorbents for use in the processof this invention.
Likewise, irregularly shaped porous sorbent.
fragments or particles: 'ha-ving z. the structure of F inorganc. oxide gels may be =used. However, in
general, spheroidal particles are to be preferred, since attrition losses-are thenat a minimum and contaminationwith gel. fines of the asphaltbearing :stock is substantially eliminated.
In general, siliceous gel particles will be used in theprocessof this invention, such assilica gel,. silica-alumina gel, .silica-zirconia gel, silicathoria gel andthelike. Porous sorptive silica glasses having a. structure approaching that of a siliceous gel likewise are contemplated for use inithe. process described herein, it being necessary,v however, that the porous glass employed have an average-pore diameter less than about 125 angstrom units," and a macropore volume of less than about 30 per cent of the total pore volume. Thesize of the porous glass particles must also be carefully controlled so as to obtain preferential sorption. of the oily constituents. Usually particles of less than 60 mesh size are undesirable. It is also contemplated that within the scope of this invention other porous materials not of the inorganic oxide gel composition which have structures approaching that of a siliceous gel and are within the above specified pore' size and particlesize limits may be employed within the scope of this invention.
Typical of the porous glasses used are those described in U. 3. 2,106,744, issued February 1, 1938, to Hood et a1. There it is disclosed that a silica-alkali-boric oxide glass of suitable com position is prepared by a fusion process. Heat treatment of this glassresults in separation of the glass into two phases; one phase is rich in alkali-boric oxide and is soluble in acids, while the other phase, which is insoluble in acid, consists of silica with a small amount of boric oxide. Extraction of this heat treated glass with acid results in a porous silica glass which can be employed as a porous absorbent separating medium in accordance with the present invention. Other types of sorbents which possess the physical structure and/or the sorbtive characteristics of inorganic oxidegels may be employed within the scope of this invention.
The invention may be most readily understood by reference to the drawings attached hereto of which:
Figure 1 is a schematic arrangement of the system'of this invention in which some of the apparatus is shown partially in section;
Figure 2 is a similar view of a modified arrangement; and,
Figure 3 is a diagrammatic flow sketch of still another modified arrangement.
All of these drawings are highly diagrammatic in form.
Turning now to Figure 1, for a study of the system of the present invention, an asphaltic bearing petroleum feed stock of relatively broad boiling range containing a vaporiaable gas oil fraction as well as heavier oily and asphaltic constituents may be introduced through conduit I 0 to tubes in a furnace I I wherein it is preheated to. a suitable flash temperature within the range about 500-850 F. The furnace i i may be of construction conventionally employed for this purpose. The preheated fraction then passes through conduit l2 to tar separator it which may be a bafiled tower of conventional construction. If desired,steam may be introduced into separator 13 through conduit i511 to assist in the vaporization of the lighter constituents of that charge. A vaporized fraction is withdrawn from the top of separator I3 and passed into the upper section of a vertical convertor I4 through conduit l5. A liquid fraction bearing high boiling oily and asphaltic constituents passes from the bottom of tower I3 through conduit I6 and is pumped by pump lI through conduit I8 and exchanger l9 and cooler ll into a deasphalting vessel 20. The deasphalting vessel is an elongated, vertical vessel which may be preferably of rectangular cross-sectional shape but which may be of other shape if desired. A solid inlet conduit 21 connects into the top of the vessel 20 and a drain duct 22 connects into the bottom of said vessel. A plurality of spaced heat transfer tubes 23 extend horizontally across the upper section of vessel 20 between an inlet header box 24 and an outlet header box 25. Cooling water under pressure may be pumped from a stream drum 26 by pump 21 into the inlet header box 24 via pipe 29. Hot water and steam may be returned to steam drum 26 via pipe 30. If desired, a heat exchange fluid other than steam may be employed. For example, a fused inorganic salt or low melting point fused metallic alloy may be circulated through tubes 23 and a suitable external cooler. Inverted troughs 3| are positioned across the vessel 20 below tubes 23 and pipes 32, closed on one end and perforated along their underside, extend along under troughs 3| and communicate with liquid charge conduit I8, outside of the vessel 20. Suitable bailles, not shown, may be positioned in the lower section of vessel 20 to insure uniform discharge of contact material from all sections of the vessel crosssection through outlet duct 22.
Below the outlet duct 22 is positioned a con tinuous perforated belt 35 which may be of screen construction, for example. The belt passes over pulleys 3G and 31, the latter pulley being driven by means of motor 38. The continuous belt is encased in a gas tight chamber 38, and a receiving chamber 45 is provided adjacent the discharge end of the belt to receive discharged contact material. A drain pan 4! is positioned under the belt 35 near its charging end to receive liquid drainings. Suitable spray devices or wash solvent distributors 42 and 43 are provided over the belt 35 along a latter portion of its path of travel to distribute washing solvent onto the contact material carried on the belt 35. Drain pans 44 and 45 are positioned below the portion of the belt which is under the distributors 42 and 43, respectively. Liquid drainings containing the unsorbed asphaltic constituents of the feed stock are drained from pan 4i through conduit 47 into the receiver 48 from which it is discharged through conduit 49, pump 50 and conduit 5!. If desired, a portion of the drainings from receiver 48 may be recycled to the deasphalting chamber via conduit 52 from which they enter the chamber 20 through perforated pipes 53, closed on the ends thereof within the vessel. Fins 54 are provided along pipes 53 to provide liquid distribution spaces thereunder. Liquid drainings from pan 45 pass via conduit 55 into receiver 56 from which it passes via conduit 38, pump 59 and conduit 59 into the first distributing device 42. Solvent for distributor 43 may enter from an outside source through conduit 6| to conduit 62 and then be pumped by pump 63 through conduit 64 to distributor 43. Alternatively solvent cycle oil may be withdrawn from a conventional conversion product fractionator 65 through conduit 66 from which it enters conduit 62. It will be noted that the arrangement described permits efiicient use of the solvent in that fresh washing solvent is sprayed onto the partially washed contact material just before the contact material is discharged from the perforated moving belt and the solvent employed for this final washing is recycled and used for the first stage of the contact material washing, being sprayed from distributor 42 onto the contact material on the belt 35 along an intermediate portion of its path of travel through chamber 39.
Spent washing solvent from pan 44 is drained via conduit ID to receiver II. Any entrained contact material fines may be removed from the bottom of receivers II and 56 through outlets 290 and 291 respectively. The spent washing solvent containing asphaltic material may then be passed from receiver II via conduit 3?, pump 68 and conduit 69 to the upper section of the tar separator l3 wherein it serves as a reflux or quenching fluid. At the same time the asphaltic constituents in the spent washing solvent are separated from the solvent in separator I3 so that the solvent may pass along with other vaporizable constituents to the conversion vessel 14. This type of operation is particularly attractive when a cycle gas oil out from fractionator 65 or a virgin gas oil-cut is employed as the washing solvent. Since the spent solvent from receiver II may exist at a relatively low temperature it may be heated by exchange with tar separator bottoms in exchanger I8 to a suit able temperature for introduction into tow-er l3. Alternatively, all or part of the washings from receiver Il may pass via conduits 53 and 72 to the inlet Ill to the heating furnace H so that it may be preheated and flashed in the tower I3 along with the charge stock. Where the solvents employed are other than gas oil or kerosene, it may be desirable to remove them from the system at I3 and treat them separately for removal of asphaltic constituents.
In order to permit uniform distribution of material from the deasphalting chamber 20 onto the moving belt 35, the discharge duct 22 from the deasphalting chamber may be of rectangular cross-sectional shape, extending in a direction perpendicular to the drawing substantially the width of belt 35. Suitable guard members, not shown, may be provided within chamber 39 to prevent contact material from falling off opposite sides of the belt 35. A slide valve 682 may be provided in duct 22 to permit control of the rate of material withdrawal from chamber 29. Any excess washing solvent which has failed to drain from the contact material by the time it is discharged from belt 35 may be purged from the contact material in receiving chamber M3 by the introduction of a suitable heated gas from conduit I4 into perforated distributor tubes '15 in chamber 40. The ends of tubes I5 within chamber 40 are closed. The purging gas should preferably be inert to the reaction in the conversion vessel. Exemplary of suitable purging gases are nitrogen, flue gas and steam.
A discharge conduit I6 is provided for withdrawal of contact material from receiving chamber 40 to seal chamber 11. At the bottom of chamber 11 there is provided a slide valve I8 which controls the fiow of contact material from seal chamber 16 into conduit 19 which in turn directs the contact material into the upper section of conversion vessel I4. The conversion vessel I4 is a substantially vertical vessel of suitable cross-sectional shape provided with a solid inlet feed leg I30 extending upwardly from its top to a supply hopper and with a solid discharge'conduitBI at its lower-end. Apartition 82 is supportedacross the upper-section of yessel I4 to define aseal chamber 83. A conduit 84 depends centrally from partition 82 and terminates shortly therebelow. A cylindrical baffle curtain 85 is supported by rods 86 centrally below the conduit 84. A skirt 8'! of substantially-less cross-sectional area at its base than the curtain 85 extends downwardly from the lower end of conduit 83 and terminates just short of the lower end of curtain 85. AcylindricalbaffleBE-having a conical shaped roof issupported by rods *I3I directly below the lower end of conduit'83. The baffle 88 is of'smaller diameter-than skirt 8I'so as to leave anannular passage-89 for contactimaterial fiow from conduit 83. A second annular passage 90 is provided for solid flow between'skirt 8? and curtain B5. Into this latter passage "contact material from conduit 19 is directed. The two separate streams of contact material from passages 89 and 90 are permitted to merge at: the lower extremities 'of these passages and the merged streams pass into an inverted conical basin 9| supported by rods 92 and 92' within vessel I4 shortly below the lower end of curtain 85. The size and position of basin 9I with respect to curtain 85 is such as to prevent overflow of catalyst over the edges of the basin 9| Orificesi93 of predetermined size are provided'in the bottom of basin 9I for discharge of mixed contact material therefrom. The above described arrangement for mixing the two separate inlet, streams of particle-form contact material-is only one of a number of arrangements which maybe employed. It is contemplated that other suitable devices adapted for mixing of two inlet streams of contact material may be substituted for the arrangement described hereinabove. In the lower section of the vessel I4 there are provided two vertically spaced rows of spaced gas-collectin troughs 95 and'96. Gas outlet conduits 91 and 99 are provided for. troughs 95 andl96 respectively. The conduits 9! and 98 are manifolded into manifolds I93 and IMrespectivelyywhich in turn are manifolded by means of conduits'l 05 and I I16, respectively, into a single discharge conduit 101. Valves I08 and I09 are'provided'on conduits I05 and I06 respectively, to permitcontrol of gas flow from each rowof collecting troughs. It will be understood that other suitable-arrangements for disengagement and withdrawalxof gaseous products from the-column of contact material'in the convertor I4 may be substituted for, that described hereinabove. Across thelower section of vessel I4, there are provided verticallyspaced apart partitions I09 and H0. Short "nipples III uniformly spaced apart depend frompartition I09 and orifices II2 are positioned in partition IIO'in staggered relationship to the nipples III. It will be noted that the number of orifices issubstantially less than the number of nipples. This-arrangement which is fully described and" claimed in United States Application Serial j Number 473,861, filed on January 28, 1943; now Patent No. 2,412,136, in which the present" applicant is one of the applicants, permits the withdrawal of contact material uniformly from all sections of the horizontal cross-section of vessel I4 tothe outlet conduit 8I.
In order to permit better mixing and more uniform distribution of the contact material passing from basin 9 I, the orifices 93,which may preferably be adjustable, are set-at such a size as to permit contact material discharge from basin 9| at thedesired total throughput rate. The suradjusting system is preferable.
gas inlets and outlets.
desirable 'to' maintain the column surface level.
The rod Hill may be rotated by a motor II3 through shaft H4 and gears I45. As the surface level of the column changes along the rod I 00, the power required to drive the electricmotor II 3 will vary. A suitable instrument I49 actuated by the change in power-requirements for motor II3 will in turn actuate a motor IM to drive valve"99 in such a manner as to compensate any change in 'the'contact material column surface level at I42.
It will be noted that according to the method of this invention the gel-type contact material serves the dual function of a sorbent inthe deasphalting operation and as a catalyst for the conversion of the sorbed oily constituents ,inthe conversion zone.
Along side of the converter I4 there is provided a vertical regeneration vessel II5 having a solid inlet H6 at its upperendand a solid outlet I'II bearing 'valve H3 at its lower. end. A suitable combustion supporting gas may be admitted to vessel I I5 from manifold I I9 through a plurality of vertically spaced gas inletpipes I20. Gas may be withdrawn from the vessel I'I4 through aplurality of spaced pipes I2I whichare vertically spaced from the inlet pipes in sucha, manneras to divide the vessel into a series of superposed burning stageseach having. separate spaced apart Theoutlet pipes I2 I-, all connect into a common outlet duct I24. A plurality of cooling stages are provided alternating with the burning stages each cooling stage having a cooling fluid inlet "I 22 and'outlet I23. Cooling tubes may be provided within each cooling stage communicating with the inlet I22 and outlet I23. A final cooling stage I provided withcooling fiuidinlet I25 and: outlet" I26 is providedb'elow the lastburning stage. 'This type of regeneration vessel'and the operation thereof is'disclosed in United States patent application Serial Number-447,432, filed June 17,1942; now'Pat." No. 2,417,399, in-which' the present applicant is one of the applicants. It should. be understood that it isconsidered to be within the. scope of this invention to substitute other types of regenerator constructions which are, adapted for the burning regenerationat controlled elevated temperatures of spentparticle-form contact materials. a A conveyorI21 is provided to transfer contact material from convertor I4 to regenerator H5 and a conveyor I28 is provided to transfer contact material from regenerator H5 to supply-hopper 80.
These conveyors may be of conventional constructiongadapted to transfer particle-form contact materialat elevated temperatures without excessive attrition; as an example, continuous bucket elevators are satisfactory.
In operation of the above described system the heavy liquid fraction from a separator I3 after being adjusted to a suitable inlet temperature by exchanger I9 and cooler I5I is sprayed bymeans of perforated tubes 32, which connect into inlet conduit I8, into the column of inorganic oxide gel particles in the deasphalting chamber 20. Hot freshly regenerated gel-type contact material is supplied into the upper end of chamber 20 from supply hopper 80 via conduit '2I at a rate controlled by valve I52. The hot contact material is cooled to a suitable temperature for the deasphalting operation by means of cooling tubes 23. Hot water under pressure may be circulated through the tubes 23 by means of pump 21 to remove heat from the contact material. Low pressure steam generated may be withdrawn from the steam drum 26 through pipe I54. The temperature at which the deasphalting operation in chamber 20 is conducted may vary over a wide range, depending upon the properties of the liquid treated. The temperature should be high enough to give the oil sufficient fluidity to permit rapid sorption of the oily constituents but low enough to permit the contact material to function selectively. The maximum temperature maintained in the sorption zone is dependent on the viscosity of the stock being treated. The sorption of oily constituents becomes less selective as the viscosity decreases. The desirable sorption temperature has been found to vary from below room temperature to about 500 F. depending on the liquid fraction treated. The temperature of the liquid introduced through tubes 32 and the contact material passing into the sorption zone below the cooling tubes 23 should be controlled to provide the desired sorption temperature The contact material should not be admitted to contact with the asphalt bearing liquid fraction at temperatures at which substantial thermal coking of the liquid fraction would take place. In general this means that the contact material should be cooled at least below about 750 F. before being permitted to contact the liquid charge.
The liquid charged from tubes 22 percolates downwardly through the column of downwardly moving contact material in the chamber 20. The residence time of the contact material within the chamber 20 may vary from about 1 to hours. depending upon the liquid fraction involved, the temperature and the ratio of the contact material to the liquid charge. In many operations it is desirable to control the residence time of the contact material in chamber 20 by means of valve I02 such as will permit substantial saturation of the contact material with sorbed oily constituents.
The ratio of contact material to liquid charge to the deasphalting chamber may vary from about 0.5 to 20 parts by weight of contact material per part of liquid asphalt bearing charge and preferably from about 2 to 6 parts of contact material per part of liquid charge.
The gel-type contact material bearing oily constituents sorbed in its pores and the liquid asphaltic material which remains substantially unsorbed is directed from chamber 20 onto the perforated moving belt 35. During that portion of the belt travel directly over the pan II most of the asphaltic liquid is drained from the contact material and withdrawn via conduit 41 to receiver 48. In some operations it may be necessary to recycle a portion of the recovered liquid from receiver 48 to chamber 20 in order to insure substantially complete separation of oily constituents from the asphaltic constituents in the liquid fraction. During that portion of the travel of belt 35 in which it moves over pans 44 and 45, a suitable washing solvent is sprayed or poured onto the contact material by means of devices 42 and 43 in order to wash away asphaltic material which adheres to the outer surface of the con tact material particles. The amount of solvent employed in the washing step may vary from about 0.25 to 2.0 volumes of solvent per volume of contact material depending upon the particular operation and. solvent involved and upon the viscosity of the unsorbed liquid. The washed contact material is then purged or blown in receiving chamber by means of a suitable heated purge gas in order to remove from its outer surface any adhering liquid so as to thereby improve the fiowability of the contact material particles. In some operations it is desirable to partially preheat the contact material at this point either by means of the hot purge gas or by means of indirect heat transfer with a suitable heating fluid. Alternatively, the contact material from washing chamber 39 may be partially preheated by passing the hot regenerated contact material charge to chamber 20, in indirect heat transfer relationship with the cooler washed contact material before the introduction of the regenerated contact material into the deasphalting chamber 20. It is also contemplated to be within the scope of this invention to charge the washed contact material directly into the reactor without an intermediate purging or heating step.
While the above described apparatus for conducting the deasphalting and the draining and washing operations represent a preferred form of this invention, nevertheless other suitable arrangements are contemplated as being within the broad scope of this invention. For example. in operations wherein the ratio of liquid to solid material charge to the deasphalting operation is high, a mixing vessel adapted to handle the solid material and liquid as a slurry may be employed as the deasphalting chamber and after the proper residence time in the sorption zone the slurry may be treated in a continuous rotary type filter for separation of asphaltic liquid from the contact material particles and for washing of the particles. Moreover, in some operations, particularly those wherein the liquid involved is of relatively low viscosity, the washing step may be eliminated and the asphaltic liquid adhering to the particles may be removed by purging and/or draining.
The washed and purged contact material bearing sorbed oily constituents then passes from chamber 40 downwardly through leg 16 into seal chamber TI wherein an inert gaseous pressure is maintained slightly above that in section I of convertor I4 by means of gas introduction through pipe IBI at a rate controlled by automatic diaphragm operated valve I62. Contact material passes from chamber 11 at a rate controlled by slide valve I8 into conduit 19 by which it is directed into the mixing device in the upper section of convertor I4. Hot regenerated contact material from hopper passes downwardly through the gravity feed leg I30 into the seal chamber 83 wherein an inert gaseous pressure is maintained slightly above the pressure in space IEO by means of gas introduced through pipe I65 at a rate controlled by diaphragm valve I68. The gas introduced to both seal chambers I? and 83 may be steam, flue gas, nitrogen, etc. The hot regenerated contact material passes downwardly from seal chamber 83 via conduit 84 into the mixing device. The stream 89 of hot regenerated contact material mixes with the stream 90 of cooler contact material bearing sorbed oily constituents so as to heat the latter stream to a temperature suitable gasoline is the desired, product.
13 for conversion of the oily constituents to lower boiling gaseous hydrocarbon products. The mixed contact material then passes as a shower from basin 9| through orifices 93 onto the surface I42 of the column of contact material maintained therebelow and then passes downwardly within said column so that the oily constituents are catalytically converted to lower boiling gaseous products. It should be understood that the word gaseous as employed herein in describing and in claiming this invention is intended in a broad sense as meaning material existing in the gaseous phase under the particular conditions of temperature and pressure involved regardless of the normal phase of such material under atmospheric conditions. The gaseous products are disengaged from the column of contact material in the lower section of the conversion zone by means of. inverted collecting troughs 95 and 96 from which it is withdrawn through conduits 9'! and 98 respectively. As pointed out hereinabove the vaporized constituents of the original petroleum charge may be introduced into the upper section of convertor it through conduit I5. The vaporized material then passes downwardly through the column of contact material in the conversion zone so as to become converted to lower boiling gaseous hydrocarbon products. These latter products are withdrawn through pipes 91 and 9B in admixture with the gaseous products from the liquid oily constituents which were recovered in the deasphalting chamber. In some operations it may be desirable to convert the vaporized portion of the petroleum charge obtained from tar separator I 3 in a separate conversion system in which case it is passed to the separate system from conduit I via conduit I61 instead of being introduced into convertor M. The
mixed gaseous products from convertor I4 are Y directed through conduit I01 into a suitable fractionator B5. Gasoline and lighter products are withdrawn from the top of fractionator 65 via conduit I68, a portion of this stream being condensed in cooler I66 and refluxed via conduit lit and a portion being withdrawn via conduit ill for further fractionation. A light cycle stock boiling within the range about 450F. to 850 F. is withdrawn from fractionator 65 via conduit 56. if desired, be employed as the washing solvent and the remainder of this cycle stock is withdrawn through conduit I12 either to be recycled to furnace H or to be used for purposes out side of the system. A heavy cycle stock is withdrawn as a product from the bottom of the fractionator 65 via conduit I13. In many operations it has been found desirable to recycle this heavy cycle stock either to furnace II or separator l3 in order that it may be ultimately converted to lower boiling products.
The operating conditions within the convertor M will vary depending upon the activity of the catalyst employed, the particular petroleum charge involved, the reaction involved and the products desired. In general it has been found desirable to maintain the pressures within a range varying from subatmospheric to about 200 pounds per square inch. Pressures of the order of 5 to 50 pounds per square inch gauge are preferred. The temperature for the conversion for cracking operations may vary from about 800 F. to 1100 F., temperatures of the order of 850 F. to 1000 F. being preferred where Where non- A portion of this cycle stock may,
'condensible gases are the principal desired product somewhat higher temperatures may be employed. The ratio of contact material to hydrocarbon throughput may vary from about 1.0 to 40 parts by weight of contact material per part of hydrocarbon charge. The ratio of fresh hot regenerated contact material introduced via conduit 84 to that bearing sorbed oily constituents and introduced via conduit l9 should be so controlled that the resulting temperature of the mixture is suitable for accomplishing the desired hydrocarbon conversion. The exact ratio used may be varied somewhat by control of the temperature of the hot regenerated contact material supplied to hopper 83 and by control of the amount of preheat given the washed contact material from chamber 39. It has been found preferable to employ about 2 to 10 parts by weight of fresh hot regenerated contact material per part of the contact material bearing the oily constituents from the deasphalting operation.
The amount of hot contact material employed may be substantially reduced in man operations by directing the vaporized hydrocarbons from tar separator l3 through conduits l5 and 3 into heater 8 wherein it is heated to a temperature above the desired reaction temperature and then passed via conduits I and 15 to the convertor. If desired a lighter and more thermally stable hydrocarbon feed such as light gas oil, naphthas or even normally gaseous hydrocarbons may be introduced at 6 into the heater 8 and then introduced into the converter to supply part of the heat requirements therein.
The spent contact material bearing carbonaceous contaminant deposited is purged substantially free or" vaporizable products by means of a suitable purge gas such as steam or flue gas introduced through. conduit H83, and the purged contact material is withdrawn from the convertor through conduit 8!. The rate of contact material throughout is controlled by orifices 93 in basin 9! and the rate of withdrawal via conduit M is automatically controlled by valve 539 to maintain the level column surface level 142 within a relatively narrow constant range. The spent contact material is conveyed by conveyor 52'? to the top of regenerator l l 5. The contact material passes as a substantially compact column downwardly through regenerator H5 while being subjected to alternating stages of burning and cooling as described hereinabove. In general during the regeneration the contact material should be maintained at a level suitable for rapid contaminant combustion but below a heat damaging level. The heat damaging level is that level at which the contact material sufiers a permanent loss in its catalytic and/or sorptive eii'iciency and may vary fromabout 1150 F. to 1450 F. depending upon the particular inorganic oxide gel-type catalyst involved. The temperature of the regenerated contact material may be adjusted to the level desired in hopper by mean-s of the cooling section provided below the lowermost burning stage.
Since the system described hereinabove depends upon gravity flow of contact material from the level of hopper 80, which is generally at a relatively low pressure, to the mixing device in space I63 of converter M wherein the gaseous pressure is higher, it is necessary to operate the washing chamber 39 under a pressure intermediate that in hopper 80 and that in section SEE: of the converter. The pressure mentioned in chamher 39 should be sufficiently high when combined with the heat of contact material provided in conduit I6 to force contact material flow into seal chamber 11. The required pressure is maintained in chamber 39 by means of a suitable inert gas introduced thereinto through conduit I80 at a rate controlled by diaphragm valve I8I and differential pressure controller I82. It is also important in the system described that the mixed solid-liquid head in deasphalting chamber 20 be sufficient to force the now into chamber 39. While this gravity flow type of system is preferred because it permits movement of the catalyst particles with the least amount of attrition thereof, it is nevertheless considered within the scope of this invention to substitute forced feed devices between the several vessels to accomplish transfer of solid material therebetween without necessary resort to gravity flow.
The system described hereinabove is adapted particularly for handling original petroleum charge stocks of relatively broad boiling range which charge stocks contain vaporizable fractions as well as heavy liquid oil and asphalt fractions.
The method and apparatus of this invention is capable of handling not only such petroleum stocks of broad boiling range but also heavier residual stocks high in asphalt content and essentially stripped of vaporizable gas oil. In Figure 2 there is shown an arrangement particularly adapted for handling such heavier stocks. Figure 2 also shows a modified arrangement for washing the contact material from the deasphalting zone and for introducing it into the conversion zone. Like elements of the systems in Figures 1 and 2 bear like numbers and the description thereof given under Figure 1 may be applied to same elements in Figure 2. In the system shown in Figure 2, high boiling residuum charge is introduced directly into the deasphalting chamber 20 via conduit I90 after being subjected to preliminary heating in exchanger [9] 'by means of the steam produced in cooling the hot regenerated catalyst supply for chamber 20 to a suitable temperature for the deasphalting operation. The deasphalting chamber employed may, if desired, be substantially the same as that employed for the processing of tar separator bottoms. The chamber 20, shown in Figure 2, is substantially the same as that shown in Figure 1 except for a modification in the solid and liquid mixing section. In the apparatus of Figure 2 a partition I93 is provided across the chamber 20 between the solid cooling and the sorption zones. Conduits I94 depend from the partition I93 for flow of cooled contact material to the sorption zone. The conduits provide a solid excluded space I95 into which liquid inlet headers I96 bearing spray nozzles I97 extend. Thus the liquid charge may be sprayed onto the surface of the contact material column in the sorption zone. A star type discharge valve 203 which may extend a substantial distance horizontally in a direction perpendic-ular to the face of the drawing is provided on the discharge duct '22 from chamber 20.
The contact material and unsorbed asphaltic liquid are directed by duct 22 onto the moving foraminate belt I98 in drain chamber I99. The chamber I99 differs from chamber 39 of Figure 1 in that it is deviated entirely to the draining operation wherein chamber 39 is devoted to both the draining and washing operation. Drained liquid bearing asphalt constituents passes through the foraminate screen into pan 4| from which it is withdrawn to receiver 48 via pipe 41. This liquid may either be Withdrawn from the system or in part recycled from receiver 48 to chamber 20 as described in connection with Figure 1.
The contact material from which unsorbed asphaltic liquid has been drained falls off the discharge end of belt I98 into a column of washing solvent maintained in a baflled washing chamber 200. The contact material falls through the column of liquid in chamber 200 in a zigzag path enforced by bafiies 20I and passes from the bottom of chamber 200 into the boot section of a bucket type elevator 203 which communicates with chamber 200. The Washed contact material is picked up by buckets 204 which may have perforated bottoms so that the wash solvent may be drained from the contact material as it is transferred to the top of the elevator. The elevator may be inclined rather than vertical or the buckets may be adequately shaped to prevent liquid draining from one bucket from falling into a bucket therebelow. The contact material is discharged from elevator 203 via chute 205 into the hopper 206 wherein it may be subjected to a partial preheat by means of indirect heat transfer with a suitable heat exchange fluid passed through tubes 20?. If desired, a suitable heating and purging gas may be introduced into hopper 205 through manifold 208 and perforated tubes 2139. In a preferred form of the operation hot cycle oil may be withdrawn from product fractionator 65 via conduit 66 and pumped by pump 210 through conduit ZII into the inlet header box 2I2 supplying tubes 20'! in hopper 206. The cycle oil thus serves to heat the contact material to a temperature of the order of about 400 F.- 700 F. and is in turn cooled to a suitable temperature for its use as a washing solvent. The cooled cycle oil passes from outlet header box 2I3 into conduit 2I4 by which it is directed into the boot section of the elevator 203 at the desired level. The cycle oil then passes from the boot section of the elevator 203 upwardly through the washing chamber 200 from which it is withdrawn through conduit 2I6 to receiver 2II. Any entrained undersized contact material is separated from the used washed oil in receiver 2 I I and withdrawn through outlet 2I8. The used washing oil is pumped by pump 2 I9 via conduit 23!] through exchangers 220 and 22I into a separate fractionating tower 222 wherein the cycle oil is recovered from the asphaltic material. The cycle oil may be withdrawn from the top of fractionator 222 via conduit 220 and condensed in exchanger 220. A portion of the condensate is refluxed to tower 222 via conduits 221 and 228 and the remainder may be withdrawn from the system via conduits 221 and 229 or returned to the system via conduits 22'! and 66. Heavy cycle stock from fractionator 05 may be passed via pipe I'i3 through exchanger Hi to supply heat to the wash cycle oil. Asphalt may be removed from fractionator 222 via conduit 23 I.
If desired, instead of employing cycle oil from fractionator 65 a suitable washing solvent such as a naphtha fraction may be introduced directly into the boot section of elevator 203 via conduit 235 instead of cycle oil from fractionator 65. In this case the used washing solvent may be sepa rated from asphaltic constituents in the same manner described for the cycle oil, and a substitute heat exchange fluid may replace the cycle oil in the tubes 201 in hopper 206. In an alternative operation the used washing solvent from receiver 2 I! may be passed through tubes 23 in the deasphalting chamber 20 as the cooling fluid in place of hot water. .becomeheated by the hot catalyst from conduit 17 The washing oil which has 2! may then be introduced into fractionator 222. In this operation the residuum liquid charge may be introduced cold into the deasphalting chamber and the inlet contactimaterial may he adjusted to a .temperaturesufficient to heat the oil upon mixing therewith toa suitabletemperature for theideasphalting operation; In still another alternative operation the spent Washing solvent from receiver 2 ll may be withdrawn via conduits 23B and 355i to-be incorporated as cutting stock in refinery fuel blends thereby eliminating the fractionator 222.
The washed and partiallyheatedcontact material from hopper 206, still bearing sorbed oily constituents may be passed-downwardly through a gravity feed leg 236 wherein it flows as a substantially compact column into the seal chambar 231. A gaseous pressure slightly above that in zone I60 of convertor i4 is maintained in seal chamber 231 by introduction thereinto of a suitable inert seal gas via conduit 239 at a suitable rate controlled by diaphragm valve 2M and differential pressure control instrument 24L The pressure maintained in seal zone 23'! and in seal zone 83, into which hot regenerated catalyst is supplied should be of the order of about onequarter to one pound per square inch above that in zone 55!! of convertor M. The contact material from seal zone 231 passes therefrom via conduit 244 at a. suitable rate controlled by slide valve 245 and is directed into the upper section of the curtained zone defined by cylindrical curtain 246. The hot contact material stream from conduit 84 is caused to mix with the cooler contact material from conduit 264 by means of the baflie members Bl and 88, which are similar to the same members in Figure 1, working together with the cylindrical curtain 245 which directs the mixed contact material onto a conical bathe 248 supported by rods 249 at a level substantially below'the lower extremity of members 81 and B3. A basin '250 which is of less diameter than vessel 24 but of greater diameter than the base of conical baflle 248 is supported by rods 25H below the baffle 248 so as to receive the contact material flow therefrom. The relative height of the sides of the basin 250 and the lower extremity of curtain 24B are fixed in such relationship as that in the arrangement of Figure 2, the total rate of contact material flow through the convertor is controlled only by means of valve 255 on the reactor bottom outlet 8! so that continuity of solid column is maintained from the valve 255 up through the solid mixing device, while in the arrangement of Figure 1, the rate of solid flow is controlled by the orifices 35% in basin 9i and the contact material is caused to shower through a short vertical section of con vertor M before reaching the column surface. In still anotherformof invention the ing device and basin shown between partition 32 and the contact'material column surface may be eliminated and the mixing of the two contact The number and material streams may be effected at the surface win the upper portion of the column itself. For example, a plurality of spaced pipes may extend down from partition 82 in the apparatus of Figure 2 to the column surface to deliver hot contact material onto the column. Also a plurality branch conduits may extend down from the end of the conduit 244 to the surface of the column for delivery of the cooler contact material onto the column surface at a plurality of points distributed uniformly across the column area. If desired, these latter branch pipes may extend a short distance below the column surface. Also if desired, the contact material from conduit 2 34 may be showered down through an upper vertical portion of the vessel onto the surface of the column while the hot contact material is delivered directly onto the column as described.
It will be noted that in the arrangement shown in Figure 2, the provision of gravity feed leg eliminates the necessity for operating the draining and washing chambers Hi9 and 2% respectively, under controlled pressures intermediate those in the hopper 8|) and in the convertor i i.
The arrangements described above all involve the passage of the mixed contact material through a confined conversion zone as a substantially compact column. This is the preferred form of this invention because it permits more accurate control of the catalyst residence time in the conversion zone, avoids channeling dimculties, limits to a minimum the attrition of the catalyst, which must of necessity be made up of particles which'are 30 mesh in size or larger and offers certain other advantages. Nevertheless, in the broader aspects of this invention it is contemplated to be within the scope of this invention that the catalyst particles may be passed through the conversion or regeneration zones or both in suspension in a gas stream or handled as a fluidized mass. Also in another less pre-- ferred operation the oil bearing contact material may be mixed batchwise in a single vessel with hot regenerated contact material and the mixture may be maintained substantially stationary in the vessel for the desired length of time, while the gaseous products are withdrawn from the vessel as formed.
As will be understood from the above discussion of the invention, a portion of the regenerated catalyst is further cooled and supplied to the deasphalting zone While the remaining portion is transferred hot to the upper section of the conversion zone to mix with and heat the oil bearing catalyst from the deasphalting apparatus. While it is the preferred form of this invention to mix fresh hot regenerated catalyst with the oil bearing catalyst from the deasphalting zone, nevertheless in the broader aspects of this invention it is contemplated that the hot catalyst which is mixed with the oil bearing cata lyst from the deasphalting operation may be hot partially regenerated catalyst or even used catalyst from the convertor discharge which has been heated and recycled to the seal zone 33. Such a modified arrangement is shown in Figure 3. In the arrangement shown in Figure 3 the asphalt bearing liquid charge is introduced via conduit are into deasphalting chamber 35 wherein it is contacted with inorganic oxide gel-type contact material particles which are introduced at a suitable temperature through duct 302. The contact material and unsorbed asphalt containing liquid then pass into chamber 3553 wherein they are separated. The contact material is then washed in chamber 304 with a suitable solvent introduced at 305 and withdrawn at 306. The washed contact material is then transferred by conveyor 30! to hopper 308 from which it flows through a gravity feed leg 309 to seal chamber 3l0. The contact material passes via conduit 31 I from seal chamber 310 to mixing chamber 3l2 wherein it is mixed with hot, at least partially spent contact material entering chamber 312 via conduit 313 from seal chamber 3|4. The mixed contact material passes at a suitable conversion temperature into the top of converter 3l5 via conduit 3l6. Gaseous conversion products are withdrawn from the convertor via conduit 3 I! and spent contact material bearing a carbonaceous contaminant, after being purged by a suitable gas introduced into chamber 315 at 3I8, is withdrawn from the bottom of convertor 315 via conduit 319 at a rate controlled by valve 320. A portion of the spent contact material is transferred via conveyor 321 to chute 322, feeding the reconditioner 323. In the reconditioner the contact material is heated to a suitable temperature for heating the oily constituent bearing contact material from hopper 308 to the desired conversion temperature. The contact material heating in vessel 323 may be accomplished either by direct or indirect heat transfer with a suitable heated heat exchange fluid introduced at 324 and withdrawn at 325. On the other hand a mixture of gaseous fuel and air may be introduced at 324 to burn and thereby heat the contact material. Preferably, how ever, a combustion supporting gas may be introduced at 324 at a rate such as will promote the burning of just a sufiicient portion of the contaminant deposited on the contact material to heat to the contact material to the required temperature. By properly controlling the gas introduced at 324, the contact material may be heated to the desired temperature level without overheating it to a heat damaging level and without the need for any cooling tubes within or after the chamber 323. In this operation the hot contact material passing from chamber 323 through gravity feed leg 325 to seal chamber 314 is partially regenerated catalyst. The remainder of the spent contact material from convertor 3l5 is transferred via conveyor 321 to chute 321, feeding to the regenerator 328 wherein it is substantially completely regenerated by means of air or oxygen, etc., introduced at 329 and withdrawn at 330. A suitable cooling fluid may be introduced through conduit 33l to suitable heat transfer tubes (not shown) within the regenerator in order to control the contact material temperature below a heat damaging level during the contaminant burning. The cooling fluid may be withdrawn from the heat transfer tubes via conduit 332. The regenerated contact material passes from regenerator 328 to cooler 333 wherein it is cooled by means of a suitable cooling fluid introduced at 334 and withdrawn at 335. The cooled contact material passes from cooler 333 via conduit 336 and is transferred by conveyor 331 to conduit 302 feeding the deasphalting chamber 30!. An inert gas, such as steam, may be supplied to seal chambers 3l0 and 3M through conduit 338 at a rate controlled by valve 339 sufficient to maintain an inert gaseous pressure in both seal chambers above the gaseous pressure in catalyst mixing chamber 312. If desired, a vaporized hydrocarbon charge may also be introduced into the convertor through conduit 339. The relative amounts of spent catalyst passing A. P. I. gravity 19.4 Pour point 45 F. Saybolt Universal viscosity at 210 F 167' seconds Conradsen carbon residue 9.4% by weight Sulfur 1.5% by weight Cleveland Open Cup flash 435 F. Cleveland Open Cup fire 505 F.
Using a silica alumina spheroidal gel catalyst of about 40 pounds per cubic foot unpacked density and average particle size of 0.129 inch (4-10 mesh size Tyler), prepared by the method described in United States Patent 2,384,946, issued September 18, 1945, to Milton Marisic, in a ratio of about 290 parts of sorbent per 100 parts of residuum charge by weight and maintaining atmospheric pressure and a temperature of about 300 F. and residence time of about two hours in the continuous type deasphalting chamber, and recycling the unsorbed liquid until substantially all the oily constituents have been removed, oily constituents amounting to about .of the charge may be separated from the asphaltic constituents contained in the above residuum charge. The catalyst bearing the sorbed oily constituents is washed with about one-half its weight of a light cycle oil, the residence time of the catalyst in the washing operation being limited to about 3 minutes. The catalyst before charging to the reactor contained about 29% of its weight of sorbed oily constituents having the following properties: A. P. I. gravity23.9, Saybolt Universal viscosity at 210 F. 83.3, kinematic viscosity at F. 210, Conradsen carbon 1.75% weight. The catalyst bearing sorbed oily constituents and existing at about 210 F. was mixed together with hot regenerated catalyst of similar type existing at about 1090 F. by flowing the two catalyt streams into a closed vessel and mixing the catalyst in the vessel. The weight ratio of hot to cold catalyst mixed exclusive of oil, was about 1.9 to one. The vaporous reaction products were withdrawn from the top of the closed vessel as fast as formed and the mixed catalyst was maintained in the vessel for about 10 minutes before withdrawing it. The estimated reaction temperature was about 960 F. and the pressure was substantially atmospheric. The following conversion yields were obtained corrected to a no loss basis:
Gas (including C4s and 17.6% by weight of C5s) (Dumas gravity sorbed oil constitu- 1.169) ents Coke on catalyst 11.0% by weight of sorbed oily constituents The coke-deposited on the catalyst was only 1.1% by weight-of'thercatalyst and wasxreadily removed by burning at temperatures within the range about 800 F.-ll F. Itwill be noted that in theabove yield data the gasoline had not been stabilized and the gas contained aiconsiderable amount of: gasoline; constituents.-- The above substantial gasoline yields were' obtained even though in the batch type operation described in this example, the vapors were withdrawnsubstantially instantaneously as formed so that the time of contact of'vapors with. catalyst was extremely short. In the continuous type-opera tion described herein wherein vapors formed must pass downwardly :through. a substantial length of catalyst column before being withdrawn, substantially higher gasolineyields with out substantial increase in coke may be expected for operating conditions similar to.those in the above example.
It will be apparent from the above that by the method of this invention-veryheavy petroleum charge stocks may be handled without incurring coke deposits on the catalyst substantially heavier than those heretofore incurred in handling much lighter, clean gas oil charge stocks.
It should beunderstood that the specific details of apparatus construction and ofoperating conditions and of conversion applications of this invention given hereinabove are illustrative and are not intended as limiting the scope of this invention except as it may belimited by the following claims.
I claim:
1. A process fOlf"C0liVlSi0Il"Of original-petrm leum stocks of broad boiling rangecontaining vaporizable fractions and heavy liquid oil and asphalt fractions at elevated temperatures in the presence of a moving contact'material which comprises, heating said petroleum. stock to a temperature below that at which substantial thermal cracking would occur but sufliciently high to effect vaporization of a substantialpcrtion of said stock separating'the vaporized portion from the non-vaporized portion of said stock, effecting removal of asphalt material from said non-vaporized portion, bringing the deasphalted non-vaporized portion into contact with a moving contact materialat suitable elevated conversion temperatures to effect convension of said non-vaporized portion, also bringing said vaporized portion into contact with said contact material at elevated'cenversion temperatures to effect the desired conversion of said vaporized portion and separatingthe mixed conversion products of said portions from said contact material.
2. The method for catalytic conversion of original petroleum stocksv of broad boiling range containing :hyd rocarbonscapable. of" being vaporized without cracking andheavy liquidoil. and
. asphalt hydrocarbons which undergo. cracking before being vaporized which comprises; heating said original petroleum .stock of broad boiling range to a temperature .atwhich a substantial fraction of said stockis vaporized but. below a temperature at which substantial thermal cracking of any of the constituents occurs, passing the heated petroleum stock into a flashing zone to separate the vaporized hydrocarbon "fraction from the non-vaporized liquid hydrocarbon fraction, subjecting said liquid fraction .toa deasphalting operation to separate the .asphalt constituents therefrom, delivering thedeasphalted liquid fraction into a. confinedconversion zone. to: be heated to arcracking temperature by means of a moving cracking catalyst'existing prises; dividing the wide boiling range feed into a low boilingfraction which is vaporizable at the desired conversion temperature and into a .high boiling asphalt containing liquid fraction which boils abovethe' desired conversion temperature, contacting said asphalt containing liquid fractions with a porous contact material having catalytic'properties for the desired conversion, said contact material containing mostly micropores and having less than 30 percent of its total pore volume occupied by pores of greater than angstrcm unit radius, controlling the variables of contact time, temperature, contact aterial average particle diameter and the relative amounts of contact material and liquid fraction to effect sorption'of oily constituentsv in said fraction into the pores of said contact material while leaving the asphalt constituents substantially unsorbed, effecting substantial separation of the contact material bearing sorbed oily constituents from the unsorbed asphalt constituents, mixing said contact material with hot regenerated contact material ofsimilar type in such proportion asto heat it to a temperature suitable for effecting the desired conversion of said oily constituents to lower boiling products, retaining the heated contact material and oily constituents in a confined conversion zone for suiilcient time to efiect said conversion, simultaneously introducing said lower boiling fraction from-the original feed into said conversion zone as a heated vapor to contact said contact material and thereby undergo conversion to lower boiling products and efiecting separation of the mixed lower boiling products from said contact material.
4. The method for conversion of wide boiling range petroleum charge stocks to lower boiling hydrocarbon products at controlled elevated temperatures in the presence of a particle-form contact material which method comprises: heating said charge to a temperature below that at which it will besubstantially thermally cracked to vaporize ,a portion thereof, passing the heated charge into a flashing zone to separate the va porized fraction from non-vaporized asphalt containing fraction, contacting the asphalt bearing liquid, fractionirom said flashing zone at a temperature below that at which said ction would be vaporized in a confined d zone with a particleeform inorganic o as 6 type contact material made up of particles greater than about 30 mesh size and characterized in that its total pore volume is limited to less than about 30 percent macro-pores, whereby oily constituents in said fraction are sorbed by said contact material and asphaltic constituents remain substantially...uns0rbed, draining unsorbed asphaltic constitutents from said contact material bearing sorbed oily constitutents, subjecting said contact material to controlled washing with a gas oil to wash it substantially free of unsorbed asphaltic constituents, returning the gas oil washings to said flashing zone as reflux, passing a suitable heated purging gas through the washed contact material to purge gas oil washings therefrom, mixing the purged contact material bearing absorbed oily constituents with hot regenerated contact material of similar pore structure and particle size in such proportion as to heat the oil bearing contact material to a temperature suitable for conversion of the oily constituents of said hydrocarbon feed to lower boiling products, passing the mixture through a confined conversion zone to effect conversion of said oily constituents to lower boiling gaseous products, simultaneously passing said vaporized fraction from said flashing zone through said conversion zone in contact with said contact material to eifect conversion of said vaporized fraction to lower boiling gaseous products, effecting separation of the mixed gaseous products and the spent contact material, passing the spent contact material through a confined regeneration zone while contacting it with a combustion supporting gas to burn off contaminant deposits from the contact material and while controlling the contact material temperature below a heat damaging level, withdrawing hot regenerated contact material from said regeneration zone, cooling a portion of the regenerated contact material to a temperature at least below about 750 F. and passing the cooled contact material to said deasphalting zone as the supply thereto, and mixing the remainder of the regenerated contact material with washed oily constituents bearing contact material to heat the same to hydrocarbon conversion temperature as aforesaid.
5. A continuous process for conversion of high boiling hydrocarbon charges to lower boiling gasoline containing products in the presence of a particle-form catalytic material which comprises: heating the hydrocarbon charge to a temperature within the range about 500 to 800 F., passing the heated charge into a tar separating zone to separate a liquid fraction bearing asphaltic constituents from vaporized material, contacting the separated liquid fraction at suitable temperatures below about 500 F. in a confined deasphalting zone with a particle-form, porous silica-alumina gel catalyst in which the pores are substantially less than about 30 percent by volume macropores, and the particles are greater than about 30 mesh size, whereby the oily constituents of said liquid fraction are sorbed in the catalyst pores and the asphaltic constituents remain unsorbed, effecting separation of non-sorbed asphaltic constituents of said liquid fraction from the catalyst bearing sorbed oily constitutents, passing said catalyst into the upper section of a confined conversion zone as a continuous stream to mix with a stream of hot regenerated catalyst of the same type in such proportions as to heat the catalyst bearing sorbed oily constituents to a suitable temperature for their conversion to lower boiling hydrocarbons passing the mixed catalyst downwardly through a lower portion of said conversion zone as a substantially compact column to accomplish the conversion of said oily constituents to lower boiling gaseous hydrocarbon products, simultaneously introducing the vaporized material from said tar separating zone into the upper section of said conversion zone and passing it downwardly through said column of catalyst to effect conversion of said vaporized material to lower boiling gaseous hydrocarbon products, withdrawing mixed gaseous products from the lower section of said conversion zone, substantially separately withdrawing used catalyst bearing carbonaceous deposits from the lower section of said conversion zone, passing the used catalyst through a regeneration zone while contacting it with an oxygen containing gas to burn 01f said carbonaceous deposits, withdrawing the regenerated catalyst from said regeneration zone, cooling a portion of said catalyst to a temperature below about 750 F. and utilizing the cooled catalyst for contacting said liquid fraction from said tar separating zone, and passing a portion of said hot regenerated catalyst as a continuous stream into the upper section of said conversion zone to mix with said oily constitutents bearing catalyst as aforesaid.
6. The method for conversion of wide boiling range petroleum charge stocks to lower boiling hydrocarbon products at controlled elevated temperatures in the presence of a particle-form contact material which method comprises: heating said charge to a temperature below that at which it will be substantially thermally cracked to vaporize a portion thereof, passing the heated charge into a flashing zone to separate the vaporized fraction from non-vaporized asphalt containing fraction, withdrawing said non-vaporized fraction from said flashing zone and effecting separation of the asphalt material from the liquid non-asphaltic hydrocarbon constituents in said non-vaporized fraction, bringing the separated non-asphaltic hydrocarbons in the liquid phase into contact with a hot contact material whereby said liquid hydrocarbons are heated to a temperature suitable for conversion thereof to lower boiling gasiform hydrocarbons, also bringing the vaporized fraction from said flashing zone into contact with said hot contact material to efiect its conversion to lower boiling gasiform hydrocarbons and separating the mixed gasiform products from the vaporized and non-vaporized charges from said contact material.
7. A process for catalytic conversion of high boiling petroleum fractions to gasoline containing products comprising, preheating an asphalt containing petroleum fraction to a non-cracking temperature at which a portion of said fraction will vaporize and separating the vaporized portion from the non-vaporized asphalt containing portion in a separation zone, separating asphalt constituents from the non-vaporized portion in a separate zone and introducing the resulting deasphaltized liquid into a confined conversion zone in the liquid phase and below conversion temperature to become heated to a catalytic cracking temperature by means of a hot catalyst and to pass downwardly through a substantially compact column of said catalyst to efiect conversion to lower boiling gasiform gasoline containing products, simultaneously passing the vaporized portion from said separation zone into contact with said catalyst in said conversion zone to efiect its conversion to gasiform gasoline containing products, withdrawing the mixed gasiform products from said conversion zone, sepa 25 rately withdrawing the catalyst from said conversion zone and subjecting it to regeneration 'by burning contaminant deposits therefrom, whereby said catalyst is reactivated and reheated for reuse in said conversion zone as aforesaid.
LOUIS P. EVANS.
REFERENCES CITED Number 26 UNITED STATES PATENTS Name Date Utterback Mar. 23, 1948 Simpson Apr. 6, 1948 Evans Nov. 15, 1949 Evans Nov. 15, 1949 Evans Nov. 15, 1949 Crowley, Jr. Dec. 6, 1949 Evans Nov. 15, 1950

Claims (1)

1. A PROCESS FOR CONVERSION OF ORGINAL PETROLEUM STOCKS OF BROAD BOILING RANGE CONTAINING VAPORIZABLE FRACTIONS AND HEAVY LIQUID OIL AND ASPHALT FRACTIONS AT ELEVATED TEMPERATURES IN THE PRESENCE OF A MOVING CONTACT MATERIAL WHICH COMPRISES, HEATING SAID PETROLEUM STOCK TO A TEMPERATURE BELOW THAT AT WHICH SUBSTANTIAL THERMAL CRACKING WOULD OCCUR BUT SUFFICIENTLY HIGH TO EFFECT VAPORIZATION OF A SUBSTANTIAL PORTION OF SAID STOCK, SEPARATING THE VAPORIZED PORTION FROM THE NON-VAPORIZED PORTION OF SAID STOCK, EFFECTING REMOVAL OF ASPHALT MATERIAL FROM SAID NON-VAPORIZED PORTION, BRINGING THE DEASPHALTED NON-VAPORIZED PORTION INTO CONTACT WITH A MOVING CONTACT MATERIAL AT SUITABLE ELEVATED CONVERSION TEMPERATURES TO EFFECT CONVERSION OF SAID NON-VAPORIZED PORTION, ALSO BRINGING SAID VAPORIZED PORTION INTO CONTACT WITH SAID CONTACT MATERIAL AT ELEVATED CONVERSION TEMPERATURES TO EFFECT THE DESIRED CONVERSION OF SAID VAPORIZED PORTION AND SEPARATING THE MIXED CONVERSION PRODUCTS OF SAID PORTIONS FROM SAID CONTACT MATERIAL.
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US2678132A (en) * 1950-03-31 1954-05-11 Socony Vacuum Oil Co Inc Endless belt adsorption
US2738880A (en) * 1948-12-20 1956-03-20 Phillips Petroleum Co Apparatus for separating components of an organic mixture
DE1018177B (en) * 1954-12-18 1957-10-24 Universal Oil Prod Co Process for converting crude oil into more valuable hydrocarbons

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US2438261A (en) * 1946-07-03 1948-03-23 Socony Vacuum Oil Co Inc Method and apparatus for conversion of fluid hydrocarbons
US2439372A (en) * 1946-06-12 1948-04-06 Socony Vacuum Oil Co Inc Method for hydrocarbon conversion
US2487796A (en) * 1948-02-06 1949-11-15 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
US2487794A (en) * 1947-12-19 1949-11-15 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
US2487795A (en) * 1947-12-20 1949-11-15 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
US2490336A (en) * 1945-11-17 1949-12-06 Socony Vacuum Oil Co Inc Method for conversion of petroleum hydrocarbons
US2531356A (en) * 1947-09-27 1950-11-21 Socony Vacuum Oil Co Inc Hydrocarbon conversion process

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US2490336A (en) * 1945-11-17 1949-12-06 Socony Vacuum Oil Co Inc Method for conversion of petroleum hydrocarbons
US2439372A (en) * 1946-06-12 1948-04-06 Socony Vacuum Oil Co Inc Method for hydrocarbon conversion
US2438261A (en) * 1946-07-03 1948-03-23 Socony Vacuum Oil Co Inc Method and apparatus for conversion of fluid hydrocarbons
US2531356A (en) * 1947-09-27 1950-11-21 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
US2487794A (en) * 1947-12-19 1949-11-15 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
US2487795A (en) * 1947-12-20 1949-11-15 Socony Vacuum Oil Co Inc Hydrocarbon conversion process
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US2738880A (en) * 1948-12-20 1956-03-20 Phillips Petroleum Co Apparatus for separating components of an organic mixture
US2678132A (en) * 1950-03-31 1954-05-11 Socony Vacuum Oil Co Inc Endless belt adsorption
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