US2853438A

US2853438A - Process for hydrocarbon boiling point reduction

Info

Publication number: US2853438A
Application number: US279403A
Authority: US
Inventors: Clyde H O Berg
Original assignee: Union Oil Company of California
Current assignee: Union Oil Company of California
Priority date: 1952-03-29
Filing date: 1952-03-29
Publication date: 1958-09-23
Anticipated expiration: 1975-09-23

Description

Sept. 23, 1958 c. H. o. BERG 2,853,438

l l PROCESS FOR HYDROCARBON BOILING POINT REDUCTION 'Filed March 29, 1952 ,www

United States Patent O PROCESS FOR HYDROCARBON BOILING POINT REDUCTION Clyde H. O. Berg, Long Beach, Calif., assignor to Union Oil Company of California, Los Angeles, Calif., a corporation of California v Application March 29,1952, Serial No. 279,403 17 Claims. (Cl. 196-52) This invention `relates generally to the conversion of hydrocarbons and in particular relates to a hydrocarbon contacting process to effect a boiling point reduction simultaneously with, if desired, other hydrocarbon conversion processes. Specifically, it relates to an improved .process and apparatus for the treatment of hydrocarbons .boiling above labout 400 F. to effect a maximum pro- .catalytic activity for hydrocarbon conversions. In Athe thermal processes a relatively heavy hydrocarbon fraction is heated to its reaction temperature bypassage through a heater wherein at least a partial decomposition to more volatile products is eifected and generally with the simultaneous production of heavy hydrocarbonaceous residual materials referred to as coke. In the catalytic processes the hydrocarbon feed is heated generally to a somewhat lower temperature and is contacted with granular solids having catalytic activity promoting the desired hydrocarbon conversion reaction.

In these conventional processes all of the materials introduced as feed and which are not converted to residual materials such as coke pass at substantially the same velocity through the reaction or conversion zone. VThus, any desired product which is formed initially is nevertheless subjected to further and unneeded treatment during itspassage through the remainder of the reaction zone and whereby a partial degradation of these materials to undesirable products invariably takes place. In spite of the fact that the gasoline range hydrocarbons thermally decompose at roughly only half the rate at which a gas oil range hydrocarbon does, still a substantial proportion of the gasoline hydrocarbons are thus lost and an unduly high gas and coke production results.

In addition, even under recycling conditions, the unreacted fraction of the feed material becomes more and more aromatic or refractory in naturevand becomes succeedingly difficult to convert under the existing temperature and pressure conditions. Thus, a certain amount of the hydrocarbon feed cannot be converted into the products having the desired boiling range.

The principal disadvantages, therefore, vof the conventional processes may be summarized as: rst, a substantial proportion of the hydrocarbon feed is converted to coke and gas; second, the residual unreacted material becomes refractory precluding operations processing the hydrocarbon feed to extinction; third, desirable boiling vrange hydrocarbons initially formed are at least partially Mice degradated before they can be removed from-the reaction zone; and fourth, a selective removal of the desired products as formed is not possible.

.The process land apparatus of the present invention successfully overcomes the aforo-mentioned disadvantages and comprises an improved operation in which a given hydrocarbon feed stock of relatively high boiling point may be converted at high efficiency into a product fraction boiling in thegasoline hydrocarbon range -withan absoluteminimum of gas and coke production and w-hich also may, if desired, simultaneously subjecteither the hydrocarbon feed or the .desirable hydrocarbons formed as products or both to theother hydrocarbon conversion reactions such as those referred to above.

lt is therefore a primary object of this inventionto provide an improved process for effecting the boiling .point reduction of hydrocarbons at improved etliciency wherein a relatively long concurrent contact of hydrocar- ,bon feed and granular solids is effected under reaction conditions of temperaure and pressure followed by a :rapid removal of the hydrocarbon products boiling in the desired range effected by a relatively short countercurrent Contact of such products with solids prior to removal from the reaction zone.

Another object of this invention 'is to provide an improved hydrocarbon boiling point reduction process which comprises concurrently contacting a moving bed of heated lgranular solids with a liquid hydrocarbon to be converted in a. reaction zone while maintaining in this zone a coun- --tercurrent llow of gas which sweeps the hydrocarbon prod- ,ucts ofv reduced boiling point countercurrently through the reaction zone for removal therefrom at high velocity to prevent the desired hydrocarbon fraction from 'being decomposed.

It is a further object of this invention to provide an improved process as stated in the foregoing objects in which the countercurrent flow of gas maintained in the reactionrzone contains hydrogen to further enhance the increased yield of hydrocarbons boiling in the desired range and to inhibit the formation of undesired products .such as coke and aromatic refractoryresidual hydrocarbons.

It is an additional object of this invention to provide :the boiling point reduction process mentioned above in `the foregoing objects in which a moving bed of granular hydrocarbon cracking catalyst is employed.

It is a further object of this invention tc provide a process for hydrocarbon conversion which etects a hydrocarbon boiling point reduction according to the objects above simultaneously with an effective desulfurization, reforming, denitrogenation, isomerization, aromatization, hydrogenation, and/or dehydrogenation whereby either the feed hydrocarbons or the product hydrocarbons y or both are further improved and upgraded.

It is an additional object to provide in such aprocess the use of a mixed catalyst whereby a hydrocarbon boiling point reduction and one or more of the named hydrocarbon conversion reactions are effected catalytically.

Av further specic object of this invention is to provideaprocess for catalytically cracking petroleum hydrocarbon fractions and recycled unconverted hydrocrabons boiling above about 400 F. by contact with a hydrocarbon cracking catalyst in the presence of a recycle gas containing hydrogen and flowing countercurrent to the catalyst flow whereby the hydrocarbons thus treated may be converted to extinction to hydrocarbon products boiling in the gasoline range.

Another'object of this invention is to provide an improved -apparatus adapted to effect the foregoing objects.

' Other objects' and advantages of the present invention.

3 will become apparent to those skilled in the art as the description and illustration thereof proceeds.

Briefly, the present invention comprises a continuous hydrocarbon-granular solids contacting process for the boiling point reduction of hydrocarbon fractions wherein a liquid hydrocarbon feed is contacted with a moving established by employing a liquid feed stream entering mass of granular solids and passes concurrently therewith y at least part way through a reaction zone under reaction conditions of temperature and pressure and in the presence of a countercurrent flow of vapor containing the hydrocarbon products of the process.. Liquid hydrocarbons are brought into contact by spraying, or are otherwise mixed with the moving bed of heated granular solids and are retained thereon by adsorption and/or wetting depending on the physical characteristics of the solid materials. The heated solids are thus at least partly saturated with liquid hydrocarbon feeds. The hydrocarbon feed in normal operation does not run down through the solids bed, especially at high solids to feed ratios, but it may to some extent at the lower ratios. Ordinarily the feed oil, at least partly saturating the solids, is carried by the moving bed of solids at least part way down through the reaction or soaking Zone maintained under conversion conditions of pressure and temperature. During this time, the boiling point reduction and hydrocarbon cracking reactions take place on the saturated solids with the formation of hydrocarbon products of increased volatility and lower boiling point. Because of the increased volatility, the products are rapidly vaporized substantially as soon as they are formed in contact with the granular solids and are rapidly removed from the reaction zone by means of a counter-current gas and vapor flow maintained at a highvvelocity therein. Heat is introduced to the reaction zone in the heated granular solids and in the heated countercurrent flow of vapor passing through the solids bed whereby heat of product vaporization is supplied. The relatively heavy hydrocarbons introduced as feed remain in contact with the granular solids as long as is necessary to form products of sucient volatility to escape from the liquid phase established on the granular solids. The granular solids move relatively slowly down through the reactor and the vapor phase can be made to move therethrough as fast as desired. The feed hydrocarbons of relatively high boiling point pass concurrently with the solids until more volatile products are formed and these products are swept rapidly countercurrent to the granular solids through the reaction zone and are removed therefrom at a rate suicient to eliminate further boiling point reduction reactions.

In the case where additional hydrocarbon conversion reactions are desirable, the granular solids may be selected to catalytically enhance either one or both of the boiling point reducing reaction and the desired additional reaction and the rate at which the desired hydrocarbon products are passed countercurrently through the reaction zone may be further varied `according to the required conditions of the additional conversion reaction.

The process employs a downwardly moving compact bed of granular solids which may or may not have catalytic activity. Preferably, Ia catalyst such as any one of the well-known hydrocarbon cracking catalysts is ernployed to increase the rate of the boiling point reduction However, in the treatment of hydrocarbon feed stocks catalytically inactive granular solids, such yas reaction.

coke, aluminum oxide, high melting point metals, ctc.,

1 may be employed to effect a noncatalytic hydrocarbon conversion on the extended surface area provided by the heated granular solids. Following the passage of the granular solids through the reaction zone they are passed through a regeneration zone and subjected to the action of an oxygen-containing gas for reheating and regeneration in the case of catalysts and returned to contact further quantities of the hydrocarbon to be processed.

The simultaneous countercurrent and concurrent flow i' o f hydrocarbons relative to the granular solids ow is aceous products in the reaction zone.

near the top of the reaction zone, the introduction of a recycle gas near the bottom 'and removal of the desired hydrocarbon products and the recycle gas in the vapor phase from near the top of the reaction zone. Thus, the hydrocarbon feed flows in the liquid phase concurrently with the solids through the reaction zone and the hydrocarbon products are removed in the vapor phase countercurrent to the solids ow. If desired, product removal may be effected above the feed inlet point thus subjecting the product to the action of fresh solids whereby the heavier or higher boiling fractions may be absorbed and returned for further reaction and/or the product may be reacted in the presence of the fresh catalyst.

The hydrocarbon product stream is removed from the reaction zone yand fractionated for the separation of gas and liquid hydrocarbons boiling in the desired temperature range from the unreacted hydrocarbons having boiling points greater than the end point of the desired product. The unreacted hydrocarbons, which do not have the aromatic and refractory characteristics of conventional hydrocarbon boiling point reduction reactions for reasons described below, are recirculated for reintroduction with fresh feed into the reaction zone. At least part of the gas recovered from the reaction zone eluent may be fractionated if desired and a. stream thereof, preferably containing hydrogen, is introduced into the bottom of the reaction zone to sweep out the hydrocarbon products countercurrently as they are formed. The desired hydrocarbons may be subject to further fractionation and are removed from the process as one or more product streams.

The recycle gas contains substantial quantities of hydrogen formed in the cracking and boiling point reduction reactions. Even in the absence of other hydrocarbon conversion processes such as aromatization, desulfurization, and other such reactions named above, this hydrogen has been found to have an extremely benecial effect upon the boiling point reduction reactions in this process whereby highly increased liquid yields are obtained. First, this hydrogen recycle sweep gas represses to a large extent the formation of heavy non-volatile hydrocarbon- Second, it represses the formation of aromatic refractory residual hydrocarbons which ordinarily prevent recycling hydrocarbons to extinction in the conventional cracking processes. Third, it effectively strips hydrocarbons from the granularsolids just prior to their removal Afrom the reaction zone keeping the liquid yield at a high value. Fourth, the hydrogen 4and the product hydrocarbons are exposed to countercurrent reaction conditions in the presence of a catalyst to further upgrade and improve the product hydrocarbons. Fifth, a rapid removal of the product hydrocarbons of desired boiling range results precluding product degradation. Sixth, the great difference in the boiling point between the hydrogen and the hydrocarbon products simplify hydrogen recovery `and recirculation.

The present invention will be more clearly understood by reference to the accompanying drawing which is described in connection with the catalytic cracking of hydrocarbons boiling in the gas oil range in the presence of a cracking catalyst according to the principles of this lnvention.

Referring now particularly to the drawing, a How diagram is given which also indicates in cross section elevation some of the structural" details of the reactor and regenerator.

In the drawing, the hydrocarbon to be converted is l passed through line 10 and combined with a recycle feed. stream lis passed through heater coil 24 wherein it The reactor feed is in the liquid phase and is distributed ontoand to at leastpartly saturate a downwardly moving bed of granular solid material circulated through the reactor and regenerator vessels in a continuous stream. Granular solids are introduced into the reactor via line 40 from the bottom of the regenerator. The granular solids; subsequently pass downwardly through separator zone 42 through line 44 provided withsolids ow control means, 46. `The -solids pass downwardly through reactor xvessel 48 as a compact moving bed, Near the bottom of the reactor48 is provided reciprocating solids feedermeans S0 whereby a uniform downward ow of solids is maintained throughout the cross sectional area of the reactor vessel. means of line 52 controlled by valve 54 and are introduced into induction `chamberS. vA conveyance fluid f under pressure is introduced thereinto by means of line 58 controlled by valve 60. The granular solids flow by gravity and the forces generated by the depressuring conveyance fluid downwardly from chamber 56 into spent solids conveyance conduit 62. The conveyance uid depressures through the conveyance conduit concurrently with-a ow of compact unfluidized granular spent solids intorthe top of regenerator vessel 64. Thrust plate 66 within separator chamber 68 applies a thrust force to the discharge of solids from conduit 62 thereby maintaining'the solids'during conveyance in substantially compact untluidized form, a condition wherein the bulk or apparent density in pounds of solids per cubic feet of occupied volume is the same during conveyance as the density of the granular solids in the moving beds passing through reactor vessel 48 or regenerator Vessel 68.

Granularfsolids are removed by Thel spent granular solids passdownwardly as a compact movingv bed through the regenerator vessel 64 whereinthe solids are contacted by an oxidizing regeneration gas thereby removing residual hydrocarbonaceous deposits on the granular solidsforming regenerated andl heated solids. Air is introduced through line 70 at a rate controlled by valve 72 together with recirculated flue gasflowing through line 74 controlled by valve 76. This regeneration gas mixture is introduced into regeneration gas engaging zone 78, passes in direct contact with'the granular solids burning the hydrocarbonaceous deposit therefrom, and the flue gases formed are removed from ue gas disengaging section 80 through line 82. "These gases may be partly disposed of to a stack and partthereof may be recirculated for dilution of the Regenerated solids pass downwardly from regeneration zone 84 into stripping zone 86 wherein they are p countercurrently contacted by stripping steam introduced through line 88 controlled by valve 90 into stripping steam engaging zone 92. The stripping steam passes partly into regeneration Zone 84 removing flue gas therefrom and partly with the regenerated solids from the regeneration column via line 94 at a rate controlled by valve 96.

The granular solids are then passed into regeneratedv solids induction chamber 98 into which is introduced a conveyance uid under pressure through line 100 controlledv by valve 102. The granular solids and the con.

granularsolids:employedforv contacting the hydrocarbons to be converted isestablished., k

The

conveyanceconduits

40 and 62,- beinglled with moving compact porous masses of granular solids, have a relatively high pressure `drop of :greater .than about 0.1 p. s. i. g. per foot of length, the actual value depend, ing upon the physical characteristics 4of the solids. Thus,

these conveyance conduits effectively seal the reactor and regenerator vessels from each other without requiring the lengthy sealing legs conventionally employed and.,

the tall supporting structures therefore required.

Referring to reactor 48, theV liquid hydrocarbon feed,

introduced either to distributors 36 yor 38, saturates the moving bed of hot catalystv with liquid hydrocarbons.

The thus saturated solids pass downwardly through primary and secondary reaction lzones"106 and 108 and, through intermediate product disengaging-zone 110 into.v tertiary reaction and soaking zone 112. The granular solids subsequentlypass through recycle. gasengagingkr zone 114, stripping zone 116, stripping gas engaging zone 118, and are subsequently removed' as described from r..

the bottom of the reactor.

In the operation of reactor 48 a number of modifican tions exist relative to the particular point or points of feed induction andr reactor effluent removal. In all of these ycases the reactor feed is a liquid vwhich is in-l troduced onto the downwardly movingbed of solidsf and moves concurrently therewith downwardly through the various zones of the vessel. Subsequently, upon `conversion of the feed to lower -boiling point materials,

a countercurrent'ow thereof together with the recycle.

gas'is maintained upwardly through the reactor to one or moreof the product outlet points. The reactor efuentis then treated in a manner described below. f

reactor48 vthrough line 120 controlled by valve 122.l

In another modication with the feedtotally introduced through line 30, thereactor effluent'is withdrawn from disengaging zone 110 through line 124 controlledby valve 126. In this modification, a certain amount of reaction time is provided in primary and secondary re-l action zones 106 and =108 before product withdrawal is made, thus'decreasing somewhatthe direct recycling-of uids from the inlet to the` outletof the reactor and also shortening the product-solids contact time. VAny products formed in

zones

106 and 108 are drawn concurrently therethrough and removed through 'line 124 -with other" products.

In another modificationwith the totalfeed being introducedthrough line 30, partftof the product'mayvbe` withdrawn through line `with the remainder of the product being withdrawn through line 124.

ln another modification of the present invention, the

reactor feed is totally introduced through line 28 and is brought into contact with the moving solids by means of distributor 36. The solids, saturatedy with feed,fpass downwardly as a moving bed from distributor 36.v The countercurrent ow of recycle gas carries the hydrocarbon products countercurrently through zones 112,

108 and 106 for removal through yline 120 controlled by` vvalve 122 at the top of the'column. This type of operaf tion permits the contacting of the hydrocarbon productsr and'recycle gas with fresh solids in zone 106 effectively adsorbing and retaining the higher boiling and less effec-,-

tively treated hydrocarbon fractions for returnwith. the bed of solids into the lower source. of the reactor. A minimum of feed bypassing results and is an operation which is particularly effective when an additional hydrocarbon conversion such as any one or more of those named above is simultaneously carried out.

ln another modification with the reactorfeed entering through distributor 36, the reactor effluent is withdrawn fromV disengaging zone 110 through line 124. Such a procedure effectively reduces the contact time which is advantageous when treating certain hydrocarbon feed stocks which are relatively easy to process in an apparatus such as that shown in the `drawing designed for treating a wide variety of materials.

In still another modification with the reactor feed entering `through distributor 36, the reactor eluent may be partly withdrawn through line 124 and the remainder be removed through line 120.

The other modifications involving reactor feed introduction simultaneously through distributors 36 and 38 are obvious from the discussion above.

The reactor effluent passes, after removal from reactor 48 following any of the procedures or a combination thereof described above, through line 128. This stream is split and passed partly through reactor feed interchanger 22 by means of line 130, and the remaining part is passed through recycle gas interchanger 132 through line 134. The partially cooled reactor effluent, resulting from combining the split streams, is passed'through line 36 through efuent cooler 138 which reduces the efliueut to near atmospheric temperature. The partially condensed reactor efuent is introduced through line 140 into separator vessel 142. The uncondensed portion passes there; from through line 144 and through recycle gas absorber 146 countercurrent to an absorption oil. The pressure conditions and the oil to gas ratio maintained in absorber 146 are suflicient to absorb normally liquid hydrocarbons present inthe gas as well as the C3 and C4 hydrocarbons together with a substantial proportion of C1 and C2 hydrocarbons if desired. The unabsorbed lean gas, con taining a substantial proportion of hydrogen, is removed from absorber 146 through line`148 and is recycled throughline 150, preheated in interchanger 132, further heated in heater coil 152, and introduced through line 154 into recycle gasengaging zone 144 iu the reactor to introduce heat and maintain the temperature of the soaking zone. Temperature conditions in the reactor are often such as to provide a net production of hydrogen and a suicient amount of the recycle gas maybe bled olf through line 156 at a rate controlled by valve 158 thereby maintaining the desired quantity and rate of recycle gas in the system. In other cases, make-up hydrogen is added to the recycle.

The rich absorption oil is removed through line 160 from absorber 146, preheated in exchanger 162V and introduced through lin'e 164 into rich oil stripper 166.

Steam or other stripping gas maybe introduced through line 168 controlled by valve 170 or the stripper may be head condenser 174 for cooling and partial condensation. The cooled mixtureis passed into separator 176 from which the net make gas is removed through line 178 controlled by valve 180 which may be a back pressure regulator. The condensate may be partly returned through line 182 to stripper 166 for reiiux and the remainder is passed through line 184 ata rate controlled by valve 186 into gasoline distillation column 18S as described below.

Returning to separator 142, the condensed portion of the reactor eiuent is removed therefrom through line 90, is pumped therefrom by means of pump 190 through line .192 controlled by valve 194 which in turn is actuated by level controller 196. This liquid stream is combined with the condensate flowing in line 184 and the mixture is preheated in preheater 198 and is introduced for distillation into distillation column 188.

Distillation column 188 produces as an overhead product a hydrocarbon fraction having the desired maximum boiling point which, for example, may be 400 F. end point gasoline. The overhead vapor ows through line 200 through condenser 202 into separator 204. Any gases remaining uncondensed are removed through line 8 .206 controlled by valve 208. The condensate is employed 1n part as reflux in column 188 flowing through line 210 while the remainder ows as a product from the process through line 212 controlled by valve 214.

Those hydrocarbon materials boiling above the vdesired end point are removed as bottoms from column 188 through line 216. Part of these materialsv are passed through line 21S, vaporized in reboiler 220 and the vapors passed through line 22 into the bottom of column 188.

The remaining part is recycled through line l12 and comninedfcr retreatment with the fresh feed owing through ine 10.

Thus, a complete cyclical hydrocarbon conversion process having unique reaction and conversion features is provided. The major proportion of the feed is converted to a product having certain desired boiling range. A small amount of make gas is removed as. a product through line 178 and a small quantity of coke is burned from the granularsolids in regenerator 64.

Following the above general description of the process, operating data are given below indicating specific procedures and conditions for the various hydrocarbon conversion processes which may be carried out according to the principles of this invention.

The hydrocarbon feed stocks suitable for conversion to products having lower boiling points in the process of the present invention include hydrocarbon naphthas, gas oils, whether straight-run or cracked, and the heavier residual type oils etc. Specifically, straight-run and/or cracked gas oil boiling above 400 F. comprises an excellent feed stock for the production of gasoline range hydrocarbons.

Preferably, the feed stock is preheated to temperatures of the order of 500 F. to 750 F. but inthose cases when higher catalyst to oil weight ratios of the order of from 3 to l5 are employed, cold liquid feed may be introduced directly onto the hot regenerated granular solids introduced into the reactor.

The type of granular solids employed in the process depends, of course, upon the process desired to be carried out. With catalytic cracking of heavy gasolines, gas oil and heavier hydrocarbons, cracking catalysts such as acid treated natural clay, silica-alumina synthetic bead catalyst, and especially the synthetic bead catalyst containing about 0.005% by weight of chromium constitute excellent catalysts in the process of this invention.

When a reforming or aromatization or dehydrogenation of the feed stock and/or the more volatile products produced therefrom is desired, a catalyst may be employed comprising chromium oxide, molybdenum trioxide, or cobalt molybdate.

reactions may be employed. These catalysts preferably are supported on a carrier such as aluminum oxide, or they may be impregnated directly upon the catalyst having the cracking activity, or a mixture of cracking and reforming catalysts may be used.

When a simultaneous desulfurization is to be carried out, the catalyst preferably comprises cobalt molybdate or mixtures of COO and M003. These catalysts are also satisfactory for the catalytic denitrogenation of the feed stock or the products produced.

The catalyst to oil ratio as measured from the relative weights of catalyst and oil` introduced into the reactor vary, of course, according to the particular reaction to be carried out. ln general, values of from about 0.5 to 15.0 may be employed with preferable values being between about 1.0 and 5.0 for catalytic cracking alone. The liquid hourly space velocity (LHSV) at which the product is removed in the recycle gas is below about 1.0, preferable values being between about 0.005 and 0.5. These catalyst to oil ratios and LHSV values also apply to the other processes named above.

One essential step in the process is the countercurrent gas recycle employed in the reactor. The quantity of this Catalysts comprising mixtures of CoO` and M003 Vor the other well-known catalysts for these recycle may be between about 50 and 10,000 s. c. f./ barrel of feed.` The' actual values depend largelyy upon the i nature of hydrocarbon conversion process carried out together with the boiling point reduction separation. Re* cycle rates of between 500 and 2,000 s. c. f /barrel are preferred for straight catalytic cracking, between about 1000 and 4000 s. c. f./barrel for simultaneous cracking and reforming, and between about 750 and 3000 s. c. f./ barrel for simultaneous cracking and desulfurization.

Therecycle gas employed preferably contains a substantial quantity of hydrogen. The actual concentration of hydrogen in the recycle gas varies with different processes and with different feedstocks. The recycle gas may contain as little as hydro-gen and as much as 95% or more hydrogen. With an unsaturated Coker pressure distillate the recycle gas contains between about and about 50% hydrogen when catalytic cracking alone is carried out. With saturatedfeed stocks, that is, for eX- arnple, a straight-run gas oil, the .recycle gas contains from to 80% hydrogen. When the principles of this process are applied to thermal contact coking of heavy oils, the recycle gas desirably contains less hydrogenand may be treated for hydrogen removal. It may be predominatelymethane and lower boiling hydrocarbon gases. The operation pressures may vary-within wide ranges such-as from atmosphericto about 5000,-p. s. i. g. With straight catalytic cracking,`pressures of the order of above p. s. i. g. arepreferredsince increased liquid yields and decreased coke laydown -is obtained.` Pressures between about 100 p. s. i. g. and Z50-p. s. i. g. are very effective. However,v pressures as high Yas about 600 p. s. i. g. maybe employed. When desulfurization or aromatization o-r hydrogenation are desired, higher operating pressures are preferable such as between about 500 p. sti. g; and 2000 p. s. i. g., with pressures of the order of 100G-p. s. i. g. to 1500p. s. i. g. being preferred.

Operation temperatures again vary depending upon the process and the` feedstock. -In general, catalysts are-'in-v troduced into -the reactor .at temperatures between yabout 800 and 1200 F. and preferably of the order of from 100 F. to as high as 600 F. above the temperature at whichthe reactor feed is introduced. In straight catalytic cracking, temperatures of between about atmospheric and about 750 F. maybe employed for the inletl feed'fternperature. Preferably, the reactor feed is introduced at about700 F. with the cracking catalyst; en-q tering at from about 700 F. to 1000-o F.

The reactionternperatures can only `be given as averages since considerablev temperature variation occurs within:the bed ofsolids in the reactor as Well as varying fromoneprocess to another withinlimits of between.

about L50091;. and about 1100 F. With catalytic crack.

ingA preferred temperatureslie between 750 F. and. 950. F.,` Withcatalytic .reforming preferred temperaturesy lie between 800 F. and.1000 F., in desulfurizationprev ferred temperatureslie between thisy invention, ,the reactiontemperatures are preferably between about 800 Fr. and 1100 F. These average reaction temperatures are the .temperatures of the granularysolids passingthroughthe

reaction zones

106 and 108 .and the soaking and stripping zone 112 shown in the drawingv and arenot necessarily the temperatures at which the feed or -solids are introduced.`

The temperature at which the hydrogen recycle gas is introducedis preferably. equal to kor somewhat higher than the average reaction temperature vwithin the reactor. Therefore, the recycle gas is preheated to temperatures of between about 700 F.and 1000 F. prior to being introduced into the reaction Zone.

The following specific examples are illustrative of the principles of the present invention applied to straight catalytic cracking for the production. of gasolinein a typical boiling point reduction process and to such a boiling point reduction process carried out simultaneously 750 F. and 950 F., andv when-thermalv contact cokingv is carried out according fto Example 1 Data for the catalytic cracking of gas oil with synthetic bead cracking catalyst according `to the present invention are given below. The feed has a 450 F. to 750 F. boiling range. The fresh feed, flowing at 10,000 barrels vper day, is combined with 20,000 barrels per actor efuent is condensed and fractionated to recover a stream of 400 F. and point gasoline. urne yield is obtained, the gasoline product being produced at a rate of 8100 barrels per day. The reactor pressure ,is maintained at a value of 185 p. s. i.v g.

Example -2 A catalyticcracking process accordingk to this inventio-n may be `carried out in Ithe manner illustrated, in

Example l by employing 540 tons per hour of acid treated naturalkr clay cracking catalyst; The ygasoline yieldV is f 7900 barrels yper .day under substantially the samenge-y action conditions as described in Example .1.

Example 3 An aromatization and reforming'process may be carried out :in the y'presence of a mixed reforming and cracking catalyst consisting of a silica-alumina 4carrier containing i 10% molybdenum oxide (M003) and synthetic-bead cat alyst as used in Example 1. .The 'recycle gas rate is 2500 s. c. f./barrel. of feed,v the feed is a heavy naphthenicy gas v loil boiling between about 475 F. and 800 F.,'the aver-1 age reaction temperature is about 950 F., land the reactor eiuent is remo-ved `at a temperatureof about 870 F. A catalyst to oil ratio on a weight basis of about 2 is employed.` The pressure of operation is 225 p. s. i. g.

Upon .fractionation/of the products, a 68% by volume. yield of aromatic gasoline containing 6% olens and 42% aromatics is obtained. .A substantial degree of aromatization thus results simultaneously with the boiling point reduction to produce'a high quality aromaticandolen v containing'gasoline boiling range stock.,

Example, .4 v

Comparable# results arer obtained in the process of Y Example 3 wherein an acid treated natural clay cracking catalyst'is impregnated with molybdenum oxide 'to promote aromatization reactions.

Example 5 molybdenum oxide, the continuous desulfurization, de- ,s

nitrogenation and boiling point reduction of 850 F. end point coker distillate containing 1.97% by weight of sulfur and 0.10%' by weightof nitrogen is carried out. The

operating pressure is 1100 p. s. i. g. and an average reactor temperature of 860 F. is used. The recycle gas rate is 3000 s. c. f./.barrel of feed. The reactor` eiliuent is fractionated and a 64%` ,yield of 410 F. endpoint gasoline is obtained containing 0.13% sulfur, and 0.005%. nitrogen. vThe catalystto oil ratio is 3.

day of oil re-v v cycle and is preheated to a temperature of 835 F. 'and' contacted with 460 tons per hour of synthetic alumina; silica bead `catalyst for a catalyst to oil,ratio of about- The catalyst is introduced at a temperature of The average reaction temperature is aboutA 860 F. The recycle gas rate is 2000 s. c. f./barrel of `feed to the reactor. This recycle gasis preheatedftoa temperature of 900 F. prior to injection into the reactor;V`v The recycle gas contains about 45% hydrogen. The re- An 81% by vol- 1 1` Example 6 Results comparable to those of Example are obtained when a mixed catalyst comprising acid treated natural clay or synthetic bead cracking catalyst and an aluminacobalt molybdate impregnated desulfurization catalyst is substituted for the catalyst of Example 5.

Example 7 The principles of the present invention are applied to contact coking employing a bed of petroleum coke granules averaging from 0.2 inch to 0.75 inch in diameter and recirculated at 12 tons per hour. ing an A. P. I. gravity of 11 is heated to a temperature of 700 F. and directly contacted at a rate of 100 barrels per day with a moving bed of coke heated to a temperature of 1050 F. A recycle gas comprising methane and hydrogen is countercurrently recirculated through the coking zone which is maintained at an average temperature of 925 F. The coker distillate yield is 86% by volume and contains an increased proportion of Coker gasoline due to the fact that the gasoline vapors produced are removed very rapidly from the reaction zone in the gas recycle.

A particular embodiment of the present invention has been hereinabove described in considerable detail by way of illustration and several specific applications of the principles of this invention have been given to illustrate the application of the invention in various modifications to a few specific processes. It should be understood that various other modifications and adaptations may be made iu applying these same principles to other hydrocarbon conversion processes by those skilled in this particular art without departing from the spirit and scope of this invention as set forth in the appended claims.

I claim:

1. A process for the simultaneous boiling point reduction and catalytic conversion of hydrocarbons which comprises passing a moving compact nonuidized granular adsorptive solid catalyst bed adapted to promote boiling point reduction and catalytic conversion of hydrocarbons downwardly through a reaction zone, at least partly saturating said adsorptive catalyst with liquid hydrocarbon feed whereby said moving bed of catalyst carries said hydrocarbons adsorbed thereon at least part way through said reaction zone in the absence of any substantial downward liquid flow therethrough maintaining a temperature within said reaction zone of between about 500 F. and about 1100 F., flowing a recycle gas containing hydrogen at a rate of between about 50 s. c. f. and about 10,000 s. c. f. per barrel of said hydrocarbon feed through said reaction zone countercurrent to the flow' of catalyst therethrough whereby hydrocarbon products of reduced boiling point vaporizing `from the liquid hydrocarbon phase contained on said catalyst are swept out of said reaction zone in the vapor phase at a rate sufficient to prevent any substantial degree of further boiling point reduction'of the hydrocarbon vapor products after vaporization from said catalyst bed while countercurrently contacting said products and said recycle gas with said catalyst forming a reaction zone effluent, cooling and partially condensing said effluent to separate normally liquid from normally gaseous components thereof, separating said recycle gas containing hydrogen from the normally gaseous fraction, heating at least part of said recycle gas, recirculating the heated recycle gas to said reaction zone, fractionating a fraction of the desired boiling range from the normally liquid fraction of said efliuent as a liquid product, and recirculating the higher boiling fraction with said liquid hydrocarbon feed to said reaction zone for retreatment. I

2. A process according to claim 1 in combination with the step of passing spent catalyst from said reaction zone through a regeneration zone, contacting said catalyst therein with a regeneration gas containing oxygen to burn Residual oil havhydrocarbonaceous deposits therefrom forming a regenerated catalyst, returning said regenerated catalyst to said reaction zone, conveying said catalyst between said zones through elongated conveyance and sealing zones therebetween as a moving mass having a bulk density substantially the same as the bulk density of said moving bed, concurrently flowing an inert conveyance fluid through said conveyance zones to generate a. substantial pressure differential greater than about 0.1 p. s. i. g. per foot and convey said catalyst while applying a thrust force to catalyst discharging therefrom to prevent iluidization, the substantial pressure differential existing across said conveyance zones effectively sealing said reaction zone from said regeneration zone.

3. A process for simultaneously cracking and catalytically converting hydrocarbon liquids to form hydrocarbon products of lower boiling range and improved quality which comprises passing a moving bed of cornpact nonfluidized granular adsorptive solid cracking and hydrocarbon conversion catalyst downwardly through a reaction zone, contacting said moving bed of catalyst therein with a liquid stream of hydrocarbon feed in an amount controlled to at least partly saturate said catalyst therewith but insutlicient to cause any of said liquid stream to ow downwardly through said catalyst bed moving through said reaction zone, maintaining reaction zone temperatures of between about 500 F. and about 1100 F., passing a countercurrent flow of hydrogen-containing recycle gas at a rate of between about 50 s. c. f. and about 10,000 s. c. f. per barrel of said hydrocarbon feed through said reaction zone whereby cracked hydrocarbons p of decreased boiling range vaporizing from the liquid hydrocarbon feed-containing catalyst are passed therewith back through said reaction zone in the vapor phase countercurrent to the catalyst ow at a rate sufficiently high to prevent substantial further crackingof the cracked hydrocarbon vapor and are removed therefrom as a reactor effluent, cooling and partially condensing said eflluent to separate normally liquid from normally gaseous components thereof, separating said recycle gas containing hydrogen from the normally gaseous fraction, heating at least part of said recycle gas, recirculating the heated recycle gas to said reaction zone, fractionating a fraction of the desired boiling range from the normally liquid fraction of said effluent as a liquid product, and recirculating the higher boiling fraction with said liquid hydrocarbon feed to said reaction zone for retreatment.

4. A process according to claim 3 wherein the Weight ratio of catalyst to hydrocarbon feed is between about 0.5 and about 15.0, said hydrogen-containing recycle' gas is introduced into said reaction zone at a temperature greater than the average reaction zone temperature, the reaction zone pressure is maintained between about atmospheric and about 5000 p. s. i. g., said liquid hydrocarbon feed is introduced at a temperature between about 500 F. and about 750 F., and said catalyst is introduced into said reaction zone `at a temperature of between about F. and about 500 F. above the feed temperature.

5. A process according to claim 3 wherein the weight ratio of catalyst to said hydrocarbon feed is between about 3.0 and 15, said catalyst is introduced at a temperature between about 800 F. and about 1200 F and said hydrocarbon feed is introduced unheated.

6. A process according to claim 3 wherein said catalyst comprises a mechanical mixture of hydrocarbon cracking catalyst and a catalyst to promote at least one other hydrocarbon conversion reaction selected from the group consisting of catalytic desulfurization, denitrogenation, isomerization, aromatization, hydrogenation, dehydrogenation, and reforming of hydrocarbons.

7. A process for simultaneously cracking and catalytically desulfurizing hydrocarbon liquids to form a desulfurized hydrocarbon product of reduced boiling point which comprises passing a moving bed of compact noniluidized bed of granular adsorptive solid cracking and hydrocarbon desulfurization-catalyst downwardly through a reaction zone, contacting said l lyst therein with a liquid stream of hydrocarbonf. feed to adsorb on and at least partly saturatesaid catalyst with said hydrocarbon liquid prior to movement of the thus treated catalyst bed containi'ngrsaid adsorbed hydrocarbon liquid through saidrreaction zone, .controlling the amount of said` feed to prevent any., substantial liquid flow downwardly through said `adsorptive catalyst bed, maintaining reaction lzonetemperatures of between about 750 IF. and about 950 F., passing a-flow of hydrogenv containing recycle gas at a rate of between about '7.50 s. c. f. and about 3000s. c. frper barrel of said hydrocarbon feed .countercurrently throughsaid reaction zone whereby cracked hydrocarbons o f decreased boiling range vaporizing from the liquidwhydrocarbon feed-containing catalyst are passed-therewith back through said reaction zone-in Vthe vapor'phase- ,countercurrent to the catalyst ow Iat a rate sufficient to eliminateany furtherisubstantial boiling point reduction reaction and are removed therefrom as a reactor efuent containing a reduced s'ulfur content, cooling and partially condensing said effluent to separate normally liquid from normally gaseous components thereof, separating said recycle gas containing hydrogen from the normally gaseous fraction, heating at least part -of said recycle gas, recirculating the heated recycle gas to said reaction zone, fractionating a fraction of the desired boiling range from the normally liquid fraction of said eluent as a liquid product, and recirculating the higher boiling fraction with said liquid hydrocarbon feed to said reaction zone for retreatment.

8. A process according to claim 7 wherein said desulfurization catalyst is selected from the group consisting of cobalt molybdate and mixtures of cobalt oxide and molybdenum trioxide.

9. A process for simultaneously cracking and catalytically reforming hydrocarbon liquids to form a reformed aromatic hydrocarbon containing product of reduced boiling point which comprises passing a moving compact nonuidized bed of granular adsorptive solid cracking and hydrocarbon reforming catalyst downwardly through a reaction zone, contacting said moving bed of catalyst therein with a liquid stream of hydrocarbon feed to adsorb on and at least partly saturate said catalyst with said hydrocarbon feed prior to movement of the thus treated catalyst bed containing said adsorbed hydrocarbon liquid through said reaction zone, controlling the rate of liquid hydrocarbon introduction so as to prevent any substantial liquid ow downwardly through said adsorptive catalyst bed, maintaining reaction zone temperatures of between about 800 F. and about l000 F., passing a flow of hydrogen-containing recycle gas at a rate of between about 1000 s. c. f. and about 4000 sc. f. per barrel of said hydrocarbon feed countercurrently through said reaction zone whereby cracked hydrocarbons of decreased boiling range vaporizing from the liquid hydrocarbon feed-containing catalyst are passed therewith back through said reaction zone in the vapor phase countercurrent to the catalyst flow and are removed therefrom as a reactor effluent containing aromatic hydrocarbons, cooling and partially condensing said effluent to separate normally liquid from normally gaseous -components thereof, separating said recycle gas containing hydrogen from the normally gaseous fraction, heating at laest part of said recycle gas, recirculating the heated recycle gas to said reaction zone, fractionating a fraction of' the desired boiling range from the normally liquid fraction of said eluent las a liquid product, and recirculating the higher boiling fraction with said liquid hydrocarbon feed to said reaction zone for retreatment.

l0. A process according to claim 9 wherein said reforming catalyst is selected from the group consisting of molybdenum trioxide, cobalt molybdate, chromium vmoving bed of cata-` 14 oxide, :and mixtures of cobalt oxide and molybdenum trioxide.

l1. A process for conversion of hydrocarbons in contactI with a compact nonfluidized bed of granular adsorptive vsolids which vcomprises passing a moving bedof granular solids downwardly by gravity throughy a reaction zone, contacting said adsorptive solids with a liquid stream of hydrocarbons to be converted whereby -said liquid hydrocarbon is adsorbed on and at least partially saturates said adsorptive solids and is carried thereby at least part way through `said reaction zone, maintaining hydrocarbon conversion conditions of pressure and tern.-v

perature within said reaction zone, and passing a countercurrent ow of gas through said reaction zone at a sutilciently high rate to sweep hydrocarbon conversion prod-" ucts of increased volatility escaping into the vapor phase from the liquid phase associated with the solids rapidly from said reaction zone without substantial further reactionthereof;

l2. A process for conversion of hydrocarbons to produce products of reduced boiling temperature which comprises passing a moving bed of compact nonfluidized granular adsorptive solids downwardly by gravity through a reaction zone, contacting the moving bed of adsorptive solids with a liquid stream of hydrocarbons to be converted whereby said hydrocarbons are adsorbed thereon so as to at least partially saturate said adsorptive solids and be carried downwardly through said reaction zone by said moving bed in the absence of any substantial concurrent liquid ow therethrough, maintaining hydrocarbon conversion conditions of temperature and pressure therein, and rapidly sweeping hydrocarbon vapor products of reduced boiling temperature vapo-rizing from said moving bed by passing a ilow of low molecular weight gas at a suiciently high rate countercurrently through said reaction zone to prevent any substantial conversion of said hydrocarbon vapor products subsequent to their vaporization from said moving bed of solids.

13. An improved process for the cracking of liquid hydrocarbons to produce hydrocarbons of decreased boiling points which comprises passing a moving bed of heated noniluidized granular adsorptive solids downwardly by gravity through a reaction zone, contacting said solids with a heated liquid stream of hydrocarbons to be cracked whereby said hydrocarbons are adsorbed thereon and carried at least part way thereby through said reaction zone, controlling the amount of said liquid stream t-o prevent any substantial liquid ow downwardly through said moving bed of adsorptive solids, maintaining hydrocarbon crackingtemperature conditions within said reaction zone whereby cracked hydrocarbon products are vaporized from said solids and maintaining a sui-ciently high rate of a low molecular weight recycle gas flow countercurrently through said moving bed to sweep hydrocarbon vapor products rapidly from said reaction zone to prevent substantial further cracking` thereof.

14. A process for catalytic cracking of hydrocarbons which comprises passing a moving bed of nonuidized adsorptive cracking -catalyst downwardly by gravity through a reaction zone, contacting said catalyst with a controlled amount of liquid hydrocarbon feed to be cracked whereby said liquid hydrocarbon is adsorbed on said adsorptive catalyst and movement -of said catalyst carries said feed adsorbed thereon downwardly through said zone and whereby no substantial flow of said liquid hydrocarbon through said moving bed results, maintaining a temperature of between about 750 F. and about 95.0 F. within said reaction zone, passing between about 500 s. c. f. and about 2000 s. c. f. per barrel of feed of a hydrogen-containing recycle gas therethrough countercurrent to said bed of catalyst at a rate sufficient to sweep cracked hydrocarbon vapors therefrom without substantial further cracking thereof, cooling and partially condensng the reaction zone eiuent, separating said hydrogen-containing recycle gas therefrom, and recirculating at least part thereof to said reaction zone.

15. A process according to claim 14 wherein said liquid hydrocarbon feed is brought into contact with said catalyst substantially at the point it is introduced into said reaction zone and saidreaction zone effluent is removed as a vapor at 'substantially the same point.

16. A process according to claim 14 wherein said reactor eiuent is removed as a vapor at a point adjacent the point at which said catalyst is introduced and said liquid hydrocarbon feed is introduced at an intermediate point within said reaction zone thereby permitting coun- References Cited in the tile of this patent UNITED STATES PATENTS 2,358,879 Redcay Sept. 26, 1944 2,429,359 Kassel Oct. 2l, 1947 2,437,532 Huifman Mar. 9, 1948 2,439,372 Simpson Apr. 6, 1948 2,450,753 Guyer Oct. 5, 1948 2,458,109 Simpson Jan. 4, 1949 2,489,628 Evans Nov. 29, 1949 2,498,559 Layng et al Feb. 2,1, 1950 2,499,304 Evans Feb. 28, 1950 2,502,958 Johnson Apr. 4, 1950 2,561,409 Ardern yJuly 24, 1951 2,606,862 Keith Aug. 12, 1952 2,684,124 Hines July 20, 1954 2,694,036 Myers Nov. 9, 1954 OTHER vREFEruiNCEs carbons, vol. III, page 333.

Claims

1. A PROCESS FOR THE SIMULTANEOUS BOILING POINT REDUCTION AND CATALYTIC CONVERSION OF HYDROCARBONS WHICH COMPRISES PASSING A MOVING COMPACT NONFLUIDIZED GRANULAR ADSORPTIVE SOLID CATALYST BED ADAPTED TO PROMOTE BOILING POINT REDUCTION AND CATALYTIC CONVERSION OF HYDROCARBONS DOWNWARDLY THROUGH A REACTION ZONE, AT LEAST PARTLY SATURATING SAID ADSORPTIVE CATALYST WITH LIQUID HYDROCARBON FEED WHEREBY SAID MOVING BED OF CATALYST CARRIES SAID HYDROCARBONS BSORBED THEREON AT LEAST PART WAY THROUGH SAID REACTION ZONE IN THE ABSENCE OF ANY SUBSTANTIAL DOWNWARD LIQUID FLOW THERETHROUGH MAINTAINING A TEMPERATURE WITHIN SAID REACTION ZONE OF BETWEEN ABOUT 500*F. AND ABOUT 1100*F., FLOWING A RECYCLE GAS CONTAINING HYDROGEN AT A RATE OF BETWEEN ABOUT 50S. C. F. AND ABOUT 10,000 S.C.F. PER BARRLE OF SAID HYDROCARBON FEED THROUGH SAID REACTION ZONE COUNTERCURRENT TO THE FLOW OF CATALYST THERETHROUGH WHEREBY HYDROCARBON PRODUCTS OF REDUCED BOILING POINT VAPORIZING FROM THE LIQUID HYDROCARBON PHASE CONTAINED ON SAID CATALYST ARE SWEPT OUT OF SAID REACTION ZONE IN THE VAPOR PHASE AT A RATE SUFFICIENT TO