US2592404A - Method for hydrocarbon conversion - Google Patents

Description

April 8, 1952 l.. P. EVANS 2,592,404

l METHOD FOR HYDROCARBON CONVERSION Filed Sept. 27. 1947 5 Sheets-Sheet l mf? Jimena/r l 00/5 PEV/IMS AGENT 0R ATTORNEY l ef mw ai rma/0mm STOCK April 8, 1952 Al.. P. EVANS 2,592,404

METHOD FOR HYDROCARBON CONVERSION Filed Sept. 2'7, 1947 5 Sheets-Sheet 2 H OPPER 9A/0 EXCHHNGE@ AGENTUR ATTORNEY HEAVY CYCLE' 6706/( April 8, 1952 L. P. EVANS METHOD FOR HYDROCARBON CONVERSION Filed sept. 27, 1947 `s sheets-sheet :s

AG ENToR ATTORNEY UNITED STATES PATENT OFFICE METHOD FOR HYDROCARBON CONVERSION Louis P. Evans, Woodbury, N. J., Vassignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York Application September 27, 1947, Serial No. 776,471

4 Claims.

This invention pertains to a process for conversion of high boiling hydrocarbons in the presence of a particle-form contact mass material. This invention deals particularly with a process without subjecting them to temperatures at which undesirable thermal cracking and excessive coking occur. As a result in order to use such high boiling stocks at all, it is necessary first and apparatus for conversion of high boiling hy- 5 to subject them to a preliminary thermal cokdrocarbon fractions which contain varying ing step to provide vsome lower boiling oily fracamounts of asphaltic constituents. tions for a subsequent catalytic cracking opera- Such conversion processes may involve treattion. By-products from the coking process are ing, reforming, polymerization, oxidation, desula heavy liquid cut which may contain a substanphurization, cracking, etc., of the hydrocarbons l( tial amount of oily constituents as well as asto form any of a number of products. A partiophal-tic constituents and a very large amount of ularly important process is the catalytic crackpetroleum coke, the disposal of -which often creing conversion of hydrocarbons, it being Well ates a serious refinery problem. known, for example that hydrocarbon fractions A major object of this invention is the proboiling above the gasoline boiling range may be l5 vision o'f a process for conversion of high boilconverted to lower boiling gasoline containing hving asphalt bearing hydrocarbon fractions which drocarbons upon being subjected to contact with process avoids the above described difficulties of a suitable solid porous catalyst at temperatures the prior art. of the order of 800 F. and upwards and at pres- Another object is the provision of a practical sures usually above atmospheric. method and apparatus for hydrocarbon conver- Heretofore such conversion processes have been sion which permits the catalytic conversion, withlimited to the conversion of relatively light, clean, out excessive coke formation, of the high boiling substantially tar or asphalt free petroleum feed oily constituents present in high boiling petrostocks because of the tendency of the asphalt leum residuums. containing stocks to cause the formation of ex- Another object is the provision of a process for cessive 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 relatively low boiling petroleum crudes are becoming less plentiful and the crudes which are most 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 catalytic conversion of hydrocarbons which is cadling charging stocks boiling over a wide range of temperatures including very heavy constituents heretofore rejected as tar separator bottoms.

Anothery object of this invention is the provision of a new method and apparatus 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 con-A the same type to heat it to a temperature suitable for the conversion of the sorbed oily constituents to lower boiling hydrocarbon products. The gaseous hydrocarbon products are separated from the spent contact material which may be then subjected to regeneration.

It has long been known that when porous adsorbents such as bauxites and natural and treated clays are contacted with liquid petroleum fractions, the asphaltic constituents may be adsorbed on the clay and thus removed from the oily constituents. Such a process is commercially employed for the decolorizing of mineral oils by percolation of the oils through clay type adsorbents. The present process is the opposite of the so-called percolation and contact filtration processes for oil refining in that, by the present process, it is the oily constituent 'and'not the asphaltic constituent which is sorbed by the contact ma-` terial. This fundamental difference makes possible the combination cracking process of this invention and permits the elimination of the asphalt materials without contamination of the catalyst thereby. It has been found that porous contact materials, having a structure corresponding V`to that of an inorganic oxide gel having a substantially uniform porosity of low macropore portant variables are time of contact between the liquid asphalt bearing charge and the sorbent in the sorption zone, temperature in the sorption zone, viscosity of the liquid charge, and to a lesser extent the ratio of liquid oil to sorbent charged to the sorption zone. Increasing time of contact and increasing temperature result in a decrease in the eiiiciency of separation of asphaltic and oily constituents. Decreasing viscosity of the liquid charge has the same effect. On the other hand increasing temperature and decreasing viscosity both result in more rapid sorption of the liquid oily constituents by the sorbent. If the ratio of sorbent to liquid charge is excessive some loss in separation eiiiciency results. By proper control of these variables some latitude in the average diameter of the sorbent employed may be provided. However, when the diameter of the particles becomes too small, the sorbent preferentially adsorbs the asphaltic constituents from the liquid charge in the same manner as Well known oil filtering clays. This is shown in Table I below in which is tabulated the deasphalting results obtained on Mid-Continent residuums using a silica-alumina gel type sorbent having a bulk density in the 4-8 mesh size range of about 0.7.

Table I Experiment Number 1 4 5 6 7 2 3 Charge Viscosity S. U. V 116.9 116.9 81.8 8l 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 30-60 30-60 60-80 30-60 4-S 4-8 vElorption Zone Contact Time 24 hrs. 24 hrs. 2 min. 2 min 2 hrs. 72 hrs. 4 hrs. Sorption Zone 'Temperature F 150 150 150 150 150 75 275 Weight Ratio of Sorbent to Liquid Charge l 1 1 l 1 1 2. 2 Properties oi Oily Constituents Retained by Sorbent:

S. U. V. 210 F. Sec 69.7 129.2 75.2 81.7 115.4 49. 7 151 Ramsbottom Carbon, Per Cent-. 1.8 2.3 3.1 2.4 i Properties of Asphaltic Materials Washed from Sorbent:

S. U. V. 210 F. Sec 164 100. l 85.9 80. 5 76.() 139. 2 650 Ramsbottom Carbon, Per Cent 2.4 2.2 2.0 3. 5 6.7

-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 inthe 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 percent of the total pore volume and preferably l0 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 essentiallythose employed in determining the bulk densities, average pore diameters, and other pore measurements of the absorbents employed in the present invention.

The size of the sorbent particles employed in the process of this invention is to some extent dependent upon the variables involved in any particular application of the process. These im- 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 was 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 residum 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-alumina gel type sorbent of 4-8 mesh size and 0.48 bulk density was employed.

In general it may be said that the particle size or the sorbent material particularly in the case of inorganic oxide gel type sorbents should be greater 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 contemplated that in its broader aspects this invention covers these latter operations as well as the operations within the speciiled preferred limits.

The porosity of the gel particles employed in the process or 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. For the purposes of the present process, particles having bulk densities of between about 0.4 and 1.1 gram per cubic centimeter are preferred. The 'bulk densities indicated correspond to an average 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 particles with a bulk density less than about 0.6 have relatively poor selectivity. However, since the selectivity of the deasphalting process improves with a decrease in temperature, particles with a bulk density less than 0.6 would be satisfactory for deasphalting stocks which can be processed at low temperatures.

The degree of porosity of a synthetic inorganic oxide gel will, in general, depend on the conditions under which it 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 sol to be ejected from a nozzle into an oil column, where the gel sets in the form of bead-like spheroids. The resulting gel 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 between about 0.4 and about 1.1 and an average pore diameter of between about 20 and about 125 Angstrom units. They proved to be excellent selective sorbents for use in the process of this invention.

Likewise, irregularly shaped porous sorbent fragments or particles having the structure of 6 inorganic oxide gels may be used. However, in general, spheroidal particles are to be preferred, since attrition losses are then at a minimum and contamination with gel fines of the asphaltbearing stock is substantially eliminated.

In general, siliceous gel particles will be used in the process of this invention, such as silica gel, silica-alumina gel, silica-zirconia gel, silica-thoria gel and the like. Porous sorptive silica glasses having a structure approaching that of a siliceous gel likewise are contemplated for use in the process described herein, it being necessary, however, that the porous glass employed have an average pore diameter less than about Angstrom units, and a macropore Volume of less than about 30 per cent of the total pore volume. The size of the porous glass particles must also be carefully controlled so as to obtain preferential scrption 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 particle size limits may be employed within the scope of this invention.

rlypical of the porous glasses used are those described in U. S. 2,106,744, issued February l. 1938, to Hood et al. There it is disclosed that a silica-alkali-boric oxide glass of suitable composition is prepared by a fusion process. Heat treatment of this glass results 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 sorbitive characteristics of inorganic oxide gels 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 l 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 -iigure 1, for a study of the system of the present invention, an asphaltic bearing petroleum feed stock of relatively broad boiling range containing a vaporizable gas oil fraction as well as heavier oily and asphaltic constituents may be introduced through conduit i0 to tubes in a furnace l i wherein it is preheated to a suitable flash temperature within the range about 50G-850 F. The furnace I! may be of construction conventionally employed for this purpose. The preheated fraction then passes through conduit i2 to tar separator i 3 which may be a bailled tower of conventional construction. If desired, steam may be introduced into separator i3 through conduit i5!) 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 converter I4 through conduit I5. 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 il through conduit I8 and exchanger I9 and cooler I5I into a deasphalting vessel 2D. 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 2| 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 steam drum 2G by pump 2l 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 3I and communicate with liquid charge conduit I8, outside of the vessel 20. .Suitable bales, 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 continuous perforated belt 35 which may be of screen construction for example. The belt passes over pulleys 36 and 31, the latter pulley being driven by means of motor 38. The continuous belt is encased in a gas tight chamber 39, and a receiving chamber 45 is provided adjacent the discharge end of the belt to receive discharged contact material. A drain pan 4I 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 4l into the receiver 48 from which it is discharged through conduit 49, pump 59 and conduit 5I. 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 55 from which it passes via conduit 33, pump 59 and conduit 63 into the first distributing device 42. Solvent for distributor 43 may enter from an outside source through conduit I to conduit 62 and then be pumped by pump S3 through conduit B4 to distributor 43. Alternatively solvent cycle -oil may be withdrawn from a conventional conversion product fractionator 55 through conduit 66 from which it enters conduit 62. It will be noted that the arrangement described permits eflicient 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 rst 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 'I0 to receiver 1I. Any entrained contact material fines may be removed from the bottom of receivers 'II and 56 through outlets 290 and 29I respectively. The spent washing solvent containing asphaltic material may then be passed from receiver 'II via conduit 61, pump 68 and conduit 69 to the upper section of tar separator I3 wherein it serves as a reux or quenching iluid. 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 I4. This type of operation is particularly attractive when a cycle gas oil cut 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 I9 to a suitable temperature for introduction into tower I3. Alternatively, all or Dart of the washings from receiver 'II may ypass via conduits 69 and 'I2 to the inlet I0 to the heating furnace II 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 29 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 |02 may be provided in duct 22 to permit control of the rate of material withdrawal from chamber 20. 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 40 by the introduction of a suitable heated gas from conduit 'I4 into perforated distributor tubes 'I5 in chamber 45. The ends of tubes 'I5 within chamber 4D 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 46 to seal chamber 7l. At the bottom of chamber 'I'I there is provided a slide valve 'I8 which controls the iiow of contact material from seal chamber 'I6 into conduit 'I9 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 |30 extending upwardly from its top to a supply hopper and with a solid discharge conduit 8| at its lower end. A partition 82 is supported across the upper section of vessel I4 to define a seal chamber 83. A conduit 84 depends centrally from partition 82 and terminates shortly therebelow. A cylindrical baffle curtain 85 is supported by rods B8 centrally below the conduit 84. A skirt 8l 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. A cylindrical baffle 88 having a conical shaped roof is supported by rods I3| directly below the lower end of conduit 83. The baille 88 is of smaller diameter than skirt 8l so as to leave an annular passage 89 for contact material flow from conduit 83. A second annular passage 90 is provided for solid flow between skirt 8'! and curtain 85. Into this latter passage contact material from conduit I9 is directed. The two separate streams of contact material from passages 89 and 98 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 9| with respect to curtain 85 is such as to prevent overflow of catalyst over the edges of the basin 9|'. Orices 93 of predetermined size are provided in the bottom of basin 9| for discharge of mixed contact material therefrom. The above described arrangement for mixing the two separate inlet streams of particleform contact material is only one of a number of arrangements which may be 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 I 4 there are provided two vertically spaced rows of spaced gas collecting troughs 95 and 96. Gas outlet conduits 97 and 99 are provided for troughs 95 and 98 respectively. The conduits 91 and 98 are manifolded into manifolds |83 and I 94 respectively, which in turn are manifolded by means of conduits |85 and |88, respectively, into a single discharge conduit |87. Valves |08 and |09 are provided on conduits |05 and |06 respectively, to permit control of gas fiow from each row of collecting troughs. It will be understood that other suitable arrangements for disengagement and withdrawal of gaseous products from the column of contact material in the convertor |`4 may be substituted for that described hereinabove. Accross the lower section of vessel I4, there are provided vertically spaced apa-rt partitions |89 and IIll. Short nipples IiI uniformly spaced apart depend from partition |99 and orifices |12 are positioned in partition II'U in staggered relationship to the nipples III. It will be noted that the number of orifices is substantially less than the number of nipples. This arrangement which is fully described and claimed in United States application Serial Number 473,851, 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 ccntact material uniformly from all sections of the horizontal cross-section of vessel I4 to the outlet conduit 8|.

In order to permit better mixing and more uniform distribution of the contact material passing from basin 9|, the orices 93, which may preferably be adjustable, are set at such a size as to permit contact material discharge from basin 9| at the desired total throughput rate. The sur face level |42 of the contact material column is then maintained within a relatively narrow range of levels all below the basin 9| by adjustment in the rate of contact material withdrawal through conduit 8| by means of valve 99. The adjustment of valve 99 may be manual but an automatic rate adjusting system is preferable. A vertical rod |00 having iins |0| fastened along its length may be supported by suitable means (not shown) within that portion of the vessel in which it is desirable to maintain the column surface level. The rod may be rotated by a motor ||3 through shaft I'I4 and gears |45. As the surface level of the column changes along the rod I 00. the power required to drive the electric motor I3 will vary. A suitable instrument |40 actuated by the change in power requirements for motor ||3 Iwill in turn actuate a motor |4| to drive valve 99 in such a manner as to compensate any change in the contact material column surface level at |42.

It will be noted that according to the method of this invention the gel-type contact material serves the dual function of a sorbent in the deasphalting operation and as a catalyst for the conversion of thesorbed oily constituents in the conversion zone.

Along side of the convertor I4 there is provided a vertical regeneration vessel H5 having a solid inlet II8 at its upper end and a solid outlet II'I bearing valve ||8 at its lower end. A suitable combustion supporting gas may be admitted to vessel ||5 from manifold i i9 through a plurality of vertically spaced gas inlet pipes |20. Gas may be withdrawn from the vessel I I4 through a plurality of spaced pipes |2| which are vertically spaced from the inlet pipes in such a manner as to divide the vessel into a series of superposed burning stages each having separate spaced apart gas inlets and outlets. The outlet pipes I2| all connect into a common outlet duct |24. A plurality of cooling stages are provided alternating with the burning stages each cooling stage having a cooling iiuid inlet |22 and outlet |23. Cooling tubes may be provided within each cooling stage communicating with the inlet |22 and outlet |23. A final cooling stage provided with cooling fluid inlet |25 and outlet |25 is provided below the last burning stage. This type of regenerationvessel and the operation thereof is disclosed in United States Patent application Serial Number 447,432, filed June 17, 1942, now Patent No. 2,417,399, in which the present applicant is one of the applicants. It should be understood that it is considered to be within the scope of this invention to substitute other types of regenerator constructions which are adapted for the burning regeneration at controlled elevated temperatures of spent particleform contact materials. A conveyor |21 is provided to transfer contact material from convertor I4 to regenerator ||5 and a conveyor |28 is provided to transfer contact material from regenerator I5 to supply hopper 80. These conveyors may be of conventional construction adapted to transfer particle-form contact material at 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 separator I3 after being adjusted to a suitable inlet temperature by exchanger I9 and cooler |5I is sprayed by means of perforated tubes 32, which connect into inlet conduit I8, into the column of inorganicoxide 1l gel particles in the deasphalting chamber 20. Hot freshly regenerated gel-type contact material is supplied into the upper end of chamber from supply hopper 80 via conduit 2| at a rate controlled by valve |52. The hot contact materia1 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 |54. 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 suflicient iuidity 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 Vfraction treated. The temperature of the liquid introduced through tubes 32 and the contact material passing into the sorption zone below the cooling tubes 23 t 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 2 volved, 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 |02 such as will Apermit 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 4| most of the asphaltic liquid is drained from the contact material and withdrawn via conduit 4I 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 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 l2 42 and 43 in order to wash away asphaltic material which adheres to the outer surface of the contact 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 40 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 flowability 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 uid. Alternatively, the contact material from washing chamber 33 may be partially preheated by passing the hot regenerated contact material charge to chamber 26, 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 ab-Ove 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 T! wherein an inert gaseous pressure is maintained slightly above that in section |60 of convertor I4 by means of gas introduction through pipe ISI at a rate controlled by automatic diaphragm operated valve |62. Contact material passes from chamber 'Il 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 |30 into the seal chamber 83 wherein an inert gaseous pressure is maintained slightly above the pressure in space |66 by means of gas introduced through pipe |65 at a rate controlled by diaphragm valve |66. The gas introduced to both seal chambers ll and 83 may be steam, iiue 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 13 heat the latter stream to a temperature suitable for conversion of the oily constituents to lower boiling gaseous hydrocarbon products. The mixed contact material then passes as a shower from basin BI through orifices 93 onto the surface |42 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 describingand 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 re gardless of the normal phase of such material under atmospheric conditions. The gaseous products are disengaged from the column of oontact material in the lower section of the conversion zone by means of inverted collecting troughs.

and 06 from which it is withdrawn through conduits 91 and grespectively. As pointed out hereinabove the vaporized constituents of the original petroleum charge may be introduced into the upper section of convertor I4 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 93 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 I3 in a separate conversion system in which case it is passed to the separate system from conduit I5 via conduit |61 instead of being introduced into convertor I4. The mixedh gaseous products from convertor I4 are directed through conduit IDI into a suitable fractionator 65. Gasoline and lighter products are Withdrawn from the top of fractionator 65 via conduit |68, a portion of this stream being condensed in cooler |69 and reiiuxed via conduit and a lportion being withdrawn via conduit I'II for further fractionation. A light cycle stock boiling within the range about 450 F. to 850 F. is withdrawn from fractionator 65 via conduit 65. A portion of this cycle stock may, if desired, be employed as the washing solvent and the remainder of this cycle stock is withdrawn through conduit |12 either to be recycled to furnace II or to be used for purposes outside of the system. A heavy cycle stock is withdrawn as a product from the bottom of the fractionator 65 via conduit I'I3. In many operations it has been found desirable to recycle this heavy cycle stock either to furnace II or separator I3 in order that it may be ultimately converted to lower boiling products.

The operating conditions within the convertor I4 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 aboutl 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 temperatures of the order of 850 to l00 F. being preferred where gasoline is the desired product. Where noncondensible gases are the principal desired product s-omewhat 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 con duit 84 to that bearing sorbed oily constituents and introduced via conduit 'I9 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 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 many operations by directing the vaporized hydrocarbons from tar separator I3 through conduits I5 and 9 into heater 8 wherein it is heated to a temperature above the desired reaction temperature and then passed via conduits l and i 5 to the converter. 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 5 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 of vaporizable products by means of a suitable purge gas such as steam or flue gas introduced through conduit |83, and the purged contact material is withdrawn from the converter through conduit BI. .The rate of contact material throughput is controlled by orifices 93 in basin 9| and the rate of withdrawal via conduit BI is automatically controlled by Valve to maintain the level column surface level i4?. within a relatively narrow constant range. The spent contact material is conveyed by conveyor |21 to the top of regenerator I I5. The contact material passes as a substantially compact column downwardly through regenerator I I5 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 suffers a permanent loss in its catalytic and/or sorptive efficiency and may vary from about 1150a 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 880 by means 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 30, which is generally at a relatively low pressure, to the mixing device in space |60 of convertor I4 wherein the gaseous pressure is higher it is necessary to operate the washing chamber 39 under a pressure intermediate that in hopper 83 and that in section |60 of the convertor. The pressure mentioned inv chamber 39 should be sufficiently high when combined with the head of contact materialprovided in conduit 16 to force contact material iiow into seal chamber 11. The required pressure is maintained in chamber 39 by means of a suitable inert gas introduced thereinto through conduit |80 at a rate controlled by diaphragm valve |8| and differential pressure controller |82. It is also important in the systemdescribed that the mixed solid-liquid head in deasphalting chamber 20 be suiiicient to force the fiow 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 ow.

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. 'I'he 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 modied 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 l and 2 bear like numerals 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 |90 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 l except for a modification in the solid and liquid mixing section. In the apparatus of Figure 2 a partition |93 is provided across the chamber 20 between the solid cooling and the sorption zones. Conduits |94 depend from the partition |93 for flow of cooled contact material to the sorption zone. The conduits provide a solid excluded space |95 into which liquid inlet headers |96 bearing spray nozzles |91 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 perpendicular 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 dust 22 ontoY the moving foraminate belt |98 in drain chamber |99. The chamber |99 diirers 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 itis withdrawn to receiver 48 via pipe 41.. This 16 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 oli the discharge end of belt |98 into a column of Washing solvent maintained in a baiiied Washing chamber 200. The contact material falls through the column of liquid in chamber 290 in a zig zag path enforced by baliles 20| 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 iiuid passed through tubes 201. If desired, a suitable heating and purging gas may be introduced into hopper 2018 through manifold 208 and perforated tubes 209. In a preferred form of the operation hot cycle oil may be withdrawn from product fractionator 65 via conduit 66 and pumped by pump 2|0 through conduit 2|| into the inlet header box 2|2 supplying tubes 201 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 2|3 into conduit 2|4 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 2|6 to receiver 2|1. Any entrained undersized contact material is separated from the used Washed oil in receiver 2|1 and Withdrawn through outlet 2|8. The used Washing oil is pumped by pump 2|9 via conduit 230 through exchangers 220 and 22| into a separate fractionating tower 222 wherein the cycle oil is recovered from the asphaltic material. The cycle oil may be Withdrawn from the tcp of fractionator 222 via conduit 224 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 re turned to the system via conduits 221 and 66. Heavy cycle stock from fractionator 65 may be passed via pipe |13 through exchanger 22| 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 separated 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|1 may be passed through tubes 23 `in the deasphalting chamber 20 as the cooling fluid in place of hot water. The washing oil which has become heated by the hot catalyst from conduit 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 contact material may be adjusted to a temperature sufficient to heat the oil upon mixing therewith to a suitable temperature for the deasphalting operation. In still another alternative operation the spent washing solvent from receiver 2I1 may be withdrawn via conduits 23 and 35o to be incorpo rated as cutting stock in refinery fuel blends thereby eliminating the fractionator 222.

The washed and partially heated contact 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 chamber 231. A gaseous pressure slightly above that in zone |50 of converter 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 24U and differential pressure control instrument 24 I. rlhe pressure maintained in seal zone 231 and in seal zone 83, into which hot regenerated catalyst is supplied should be of the order of about one-quarter to one pound per square inch above that in zone |60 of convertor I4. 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 S4 is caused to mix with the cooler contact material from conduit 244 by means of the baffle members 81 and 88, which are similar to the same members in Figure 1, working together with the cylindrical curtain 246 which directs the mixed contact material onto a conical baflle 248 supported by rods 249 at a level substantially below the lower extremity of members 81 and 88. A basin 250 which is of less diameter than vessel I4 but of greater diameter than the base of conical baflie 248 is supported by rods 25| below the baiiie 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 246 are fixed in such relationship as to prevent contact mate-v rial from overflowing the basin 250. Contact material passes from basin 258 through a plurality of uniformly spaced conduits 253 onto the surface 254` of the contact material column in the vessel I4. The number and size of conduits 253 are such that the conduits 253 provide a solid flow capacity in excess of the maximum anticipated rate of flow. The above described arrangement differs from the mixing device shown in the convertor I4 of Figure 1 in that in the arrangement of Figure 2, the total rate of contact material ow through the convertor is controlled only by means of valve 255 on the reactor bottom outlet 8l 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 93 in basin 9| and the contact material is caused to shower through a short vertical section of convertor I4 before reaching the column surface. In still another form of this invention the mixing device and basin shown between partition 82 and the contact material column surface may be eliminated and the mixing of the two contact material streams may be effected at the surface o1'- in the upper portion 18 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 244 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 23S eliminates the necessity for operating the draining and washing chambers |99 and 250 respectively, under controlled pressures intermediate those in hopper B and in the convertor I4.

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 difficulties, 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 uidized mass. Also in another less preferred 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 cf 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 inthe broader aspects of this invention it is contemplated that the hot catalyst which is mixed with the oil bearing catalyst 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 t3. Such a modified arrangement is shown in Figure In the arrangement shown in Figure 3 the asphalt bearing liquid charge is introduced via conduit 30@ into deasphalting chamber 357i wherein it is contacted with inorganic oxide geltype contact material particles which are introduced at a suitable temperature through duct 392. The contact material and unsorbed asphalt containing liquidy then pass into chamber 393 wherein they are separated. The contact material is then washed in chamber 35d with a suitable solvent introduced at 305 and withdrawn at (itt. The washed contact material is then transferred by conveyor 3511 to hopper 308 from which it flows through a gravity feed leg 399 to seal chamber 310. The contact material passes via conduit 31 I from seal chamber 310 to mixing chamber 312 wherein it is mixed with hot, at least partially spent contact material entering chamber 312 via conduit 313 from seal chamber 314. The mixed contact material passes at a suitable conversion temperature into the top of convertor 315 via conduit 316. Gaseous conversion products are Withdrawn from the convertor via conduit 311 and spent contact material bearing a carbonaceous contaminant, after being purged by a suitable gas introduced into chamber 315 at 318, 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, however, a combustion supporting gas may be introduced at 324 at a rate such as will promote the burning of just a sufficient portion of the contaminant deposited on the contact material to heat 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 32o to seal chamber 314 is partially regenerated catalyst. The remainder of the spent contact material from convertor 315 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 331 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 333 and is transferred by conveyor 331 to conduit 302 feeding the deasphalting chamber 301. An inert gas, such as steam, may be supplied to seal chambers 310 and 314 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 from conveyor 321 to regenerator 328 and to reconditioner 323 may be controlled by means of valves 340 and 341 on chutes 321 and 322 respectively. Alternatively two separate conveyors may be used at this point in the system.

By way of example of this invention, a mid continent crude petroleum residuum having the following properties may be deasphalted in a suitable deasphalting chamber in the manner described:

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. gravity- 23.9, 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 catalyst 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 l0 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:

Gasoline 410 F. E. P. of low vapor pressure 26% by weight of sorbed oily constituents Cycle Oil 45.4 Gas (Including C4s and Css) 17.6% by weight of (Dumas Gravity 1169)-- sorbed oily constituents Coke on Catalyst 11.0% by weight of sorbed oily constituents The coke deposited on the catalyst was only 1.1% by weight of the catalyst and was readily removed by burning at temperatures within the range about 800 F.ll00 F. It will be noted that in the above yield data the gasoline had not been stabilized and the gas contained a considerable acuarios' 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 withdrawn substantially instantaneously as formed so that the time of contact of vapors with catalyst was extremely short. In the continuous type operation described herein wherein vapors formed must pass downwardly through a substantial length of catalyst column before being withdrawn, substantially higher gasoline yields Without 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 oi this invention very heavy 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 be understood that the specific details of apparatus construction and of operating conditions and of conversion applications of this invention given hereinabove are illustrative and are not intended as limiting the scope of this in vention except as it may be limited by the following claims.

I claim:

l. A process for catalytic conversion of the oily constituents in asphaltbearing hlghboilinghydrocarbon fractions to lower boiling products at controlled elevated temperatures in the presence of a particle-form catalyst which comprises: contacting the asphalt bearing fraction with a particleform catalyst existing at a temperature below about 759 F. which is substantially below the temperature at which said fraction undergoes conversion to lower boiling products and having a structure in which the total macropore volume is less than about 30 percent of the total pore vol` urne and the minimum average particle diameter is greater than about 60 mesh while controlling the temperature suitable for sorption of oily constituents by said catalyst, separating the unsorbed asphaltic constituents from the catalyst and passing the catalyst bearing sorbed oily constituents in admixture with a suilicient quantity of hot freshly regenerated catalyst of the same type to heat it to a suitable temperature for conversion of said oily constituents at least in part to lower boiling gaseous hydrocarbon product downwardly through a confined conversion zone as a substantially compact column to eect conversion of said oily constituents to gaseous hydrocarbon product, said hot catalyst existing initially at a temperature substantially above said suitable conversion temperature, withdrawing said gaseous product from said conversion zone, separately withdrawing used catalyst bearing carbonaceous contaminant deposited from said conversion zone, passing said used catalyst through a separate burning zone while contacting it therein at controlled elevated temperatures with a combustion supporting sas to burn said deposits, and mixing the regenerated catalyst While hot with said catalyst bearing oily constituents as aforesaid.

2. A process for conversion of a liquid hydrocarbon charge to a lower boiling product which comprises, contacting the liquid hydrocarbon charge with a particle form solid adsorbent catalyst existing at a temperature below about 750 F., which is below that at which said charge will vaporize and substantially below that at which said charge will undergo conversion to a lower boiling product, to effect sorption of the charge onto said catalyst, mixing said catalyst bearing the liquid charge with suilicient hot catalyst material of similar type existing at a temerature substantially above the conversion temerature to heat the liquid bearing catalyst to a temperature suitable for converting said charge at least in part to lower boiling vapor-ized products, passing the mixture through a conversion acne to complete said conversion, separating the vapcrized products from the spent catalyst, passing the spent catalyst through a regeneration sone while contacting it with an oxygen contain ing gas therein to burn ofi contaminants deposited cn the catalyst, cooling a portion of the regenerated catalyst and reusing for sorption of liquid charge and utilizing the remainder` of the regenerated catalyst as the hot catalyst for adrnixture with the liquid bearing catalyst.

3. A process for conversion oi? a high boiling liquid hydrocarbon charge to a lower boiling product which comprises, contacting the liquid hydrocarbon charge with a particle-form solid sorbent contact material existing at a temperature below about 750 F. which is substantially below the temperature for said conversion so as to effect sorption of said liquid into the pores of said sorbent, mixing said sorbent bearing the liquid charge with surhcient hot sorbent contact material of similar type existing at a temperature substantially above the desired conversion temperature to heat the liquid bearing sorbent to a temperature suitable for converting said charge at least in part to lower boiling vaporized products, passing the mixture through a conversion zone to complete said conversion and separatingr the vaporized lower boiling products from the sorbent.

4. A process for the conversion of oily constituents present in asphalt bearing high boiling liquid hydrocarbon fractions which comprises: contacting the asphalt bearing fraction with a porous particle form catalyst material of substantial particle size as distinguished from powdered contact material and having its pore volume devoted mostly to micropores and less than 30 percent of its pore volume devoted to pores having radii greater than about Angstrom units to effect sorption of the oily constituents of said fraction in the pores of said catalyst material particles, said catalyst material'existing at a temperature below about 750 F. which is below the conversion temperature, effecting a, substantial separation of unsorbed liquid from the catalyst material particles bearing sorbed oily constituents and mixing the separated catalyst material bearing said oily constituent with sufficient hot catalyst material oi similar type existing substantially above the desired conversion temperature to heat the oil bearing catalyst material to a temperature suiable for the desired conversion of said oily constituents.

LOUIS P. EVANS.

REFERENCES CITED The following references are of record in the le oi' this patent:

UNITED STATES PATENTS Number

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