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Oct. l, 1946. ~ , c. H. o. BERG Y 2,408,600 CRACKING PROCESS` >Filedsept` 22, 194s ¿y 58577 ' ' Separator' _ 6 31T' ¿'97 _____ 24d 'Hopper' v .i â ¿ FZ/e/ anda/’r v - Burner/Í f3 t Ñ f?. 9 _4?4 5 14 15 J0 l l . \ Éeac?of i _33 5Z...l 30 4! ' 40 . _ y F/„e @as ' ' ¿5 J8 _ j Regeneration 6 Chamber l _ . 17 - 5a@ 35 Affe» -\ « 19 0 21 » Off/Fae -’f_êîdv _ j ’90 ~ 26’ 22 .QF . '- f ' ¿i9 4 l ¿fr v ' ¿Cl ` - v lNvENToR. CZyoEEO. 559e, BY WMM 2,408,600 Patented oct. 1, 1946 UNITED STATES PATENT OFFICE GRAC'KING PROCESS Clyde’H. 0. Berg, Long Beach, Calif., assignor to Union Oil Company of California, Los Angeles, Calif., a corporation of California Application September 22, 1943, Serialv No. 503,345 7 Claims. (Cl. 196-52) 1 2 figure, wherein a catalytic reactor is positioned This invention relates to the catalytic conver above a' catalyst regeneration chamber, and a sion of hydrocarbons, and especially to the crack continuous solid' stream of granulated catalyst flows down' through both chambers-l,v the catalyst moving stream of granular catalyst. Catalytic cracking processes are known wherein Ul being carried back to the t'opl of the reactor by ing of petroleum fractions in the presence of a suspension in a gaseous stream of vaporized feed. the crackingy is carried~out in the presence of moving catalysts, and these processes are among the most efñcient in use today. The. known proc Referring to the iigure, vaporized and pre' heated hydrocarbon feed is introduced through line Iv and control valve 2. In> mixing section 3 this feed' gas is> mixed~ wtih catalyst from line esses of this nature are of two different types, namely (l) the fluid type, and (2) the moving - bed type. Each of and disadvantages. 4, and’ carries this catalyst in suspension upward these has its own advantages through line 5 and into separator 6-. Here the gas is separated from thev catalyst and passes-out through line l.' The catalyst drops through line 3| into hopper 8; and thence downward in a solid moving, bed' or stream through sealing leg 9 into reactory I0'. In reactor I0 the catalyst is heatedl by- indirect V The fluid- type process employs a powdered or dust-type catalyst which is blown through the reaction zone by a stream of feed vapors, and then is separated from the vaporous conversion products, and regenerated by being blown through a regeneration zone by a stream of air. heat exchange with hot- combustion gases passing The moving bed type process employs a granular or bead type catalyst, which moves down 20 through tube 26 and obtained byr burning fuel with air in burnerV H'. The hydrocarbon va ward as a solid. bed through a reaction zone pors from line 'l' are introduced- near the bottom through which a countercurrent stream of feed of the reactor through lines I2‘and 2-4 and valves vapors is passed, and then is separated from the ‘l3` and 3l', and are subjected tocountercurrent vaporous conversion products, mechanically con veyed to the top of a regeneration zoneV through 25 contact with the flowing' catalyst. The product vapors' leave the" top of the reactorl through line which it moves downward in a solid bed through I4 and valve 3A, which are kept' clear ofV catalyst which air for regeneration is passed, the regen by passing the' catalyst down through tubes I5, which extend. below outlet t4 and thus provide erated catalystv being separated and mechanically conveyed> to the top of the reaction zone for re use. f » 30 a disengaging'space. ' The used catalyst drops from the- lower party of The fluid processvhas some advantages over reactor 1'0 through sealing leg 30" into regenera the moving bed process in simplicity of construc tion chamber |61 where` it is regenerated by con' tion of reactor and regenerator chambers, but has tact with air entering through line 35‘ and valve disadvantages in diñ'ìculty of separation of the catalyst from the gas streams, with -attendant 35 36, and-` is cooled by indirect heat exchange'with a c-ooling medium entering through line I1 and catalyst loss, and diiiiculty of control of regener leaving through linev I8.A The regeneration flue ation temperatures. The moving `bed process has gases leave through line 25, and the regenerated the advantage over the fluid process in lower cat catalyst leaves the bottom’ of the chamber through alyst loss, more easily controllable regeneration temperatures and less. difficult catalyst separa 40 conical' section I9: containing baiile 20', drops through line 2 I' containing shut-off Valve 22 and tion, but the two mechanical Vconveyor systems in orifice 23 into line Y4, and repeats 'its cycle. Cat volved are very expensive to b-uild and maintain and must be adjusted frequently vto balance the reaction system against the regeneration system. alyst lmay be withdrawn from thef'system through line 28 and> valve 29 or added> to' the hopper 8 A process has now been discovered which has 45 through line 2l. There are many advantages in the above" de rthe advantages of both of the above systems with scribed process over conventional processes. The out their disadvantages. Briefly the process in equipment is simplev to' construct and operate. volves movement of a granulated catalyst in a There are no" complicated mechanical conveyor single continuous path, the catalyst being car rie/d:v from the bottom to the top'öf its path by 50 systems,v and catalyst separation is simple and suspension in a flowing stream of gas, and'thence after separation from the suspending gas, flowing downwardv in a continuous solid moving` .bed through zones of reaction and regeneration. One form of 'the îprorcess‘is illustrated in the" attached ,_ 55 eflicient with the preferred granular catalysts. There is no necessity` for “balancing” of the flow of catalyst through the reactor.l against the flow through~ the regeneration. chamber, since both flows arey part »ofi a» single continuous' cycle. Im '2,408,606 3 4 processes involving primarily a change in struc~ ture without substantial change in molecular a desirable preliminary cracking in line 5. Weight, such as hydrogenation and dehydrogen Separator 6 may be a conventional cyclone ation, aromatization, isomerization, and the like. separator, and the reactor, regeneration cham ber and auxiliary equipment are of simple de UI By refining is meant4 the conversion of small troducing hot feed into line I appears to give amounts of undesirable hydrocarbons or con sign and fabricated from common materials of construction. N o baflies, packing, etc. are neces? sary in themain body of the hopper, reactor, or regeneration chamber, although they may be employed if desired. The regeneration cham ber may be of multi-tube or multi-coil design with multiple air inlets and flue gas outlets to provide very close temperature control if de sired. Similarly, the reactor may be equipped with multiple heaters, and multiple feed inlets and outlets if desired, to control contact time and temperature to provide either isothermal operation or operation with the desired tem-_ perature gradient. Multiple tubes may also be used in place of the single line 5 shown. Baffie 20 is merely a circular shield located centrally in conical section i9 to prevent the ñow through the central portion of the regeneration cham taminants to less objectionable forms, as in the polymerization of color and gum unstable oleñns, dioleflns, and the like, conversion of sulfur, 10 oxygen, and nitrogen-containing contaminants in hydrocarbon stocks to easily removable forms such as HzS, H2O, NH3 and the like. I The hydrocarbon feed stocks may be various petroleum fractions, such as natural or cracked gases, natural, crude or cracked gasolines, kero senes, gas oils, lubricating oils, extracts, or other products obtained by conversion or extraction of such stocks; or similar fractions from coal tar, shale and the like. These may be converted by the appropriate treating processes of the pre~ 20 ber from exceeding materially the ñow through the outer portion. If desired, any catalyst fines leaving with the gases in lines 1, I4 and 39 may be removed by Cyclones, Cottrell precipitators, vious paragraph to stable, high-octane gasolines, specific olefms, aromatics, naphthenes, or iso parañ'ins, or other desired products.’ As examples of the above processes, a gas oil fraction from petroleum may be vaporized and heated to about 800° F., the vapors being intro duced into line I. These vapors pick up cata lyst from line 4 and carry the catalyst upward to settlers or the like. Any small loss of catalyst separator 6 from which the catalyst flows through may be compensated for by the addition of new catalyst through line 21. The effectiveness of 30 the hopper, reactor, and regenerator as pre viously described. The feed vapors from sepa sealing legs such as lines 9, 30 and Z‘! may be rator 6 are introduced at the bottom of reactor improved by injecting a sealing gas such as I0 as indicated, being further preheated in line steam, flue gas, carbon dioxide, nitrogen, and 24 if desired. An auxiliary gas such as hydro the like into the side of the lines at some point gen, a light hydrocarbon or an inert gas may be .or points not too close to either end. This is introduced into this stream through line 39 and illustrated in the ligure by the addition of steam valve 38, if desired, and this gas may be pre into line 30 through line 40 and valve 4I. heated to supply any additional heat desired. In a second method of operation, hydrogen or a light hydrocarbon gas may be fed through line y For example, a, propane or butane or lighter frac _I to carry the catalyst through line 5, and the 40 tion from the product may be preheated to 1100° F. and introduced into 39 so as to increase the hydrocarbon feed may be introduced through temperature of the mixture in line 24 to 900° F. valve 33 and lines 32 and I2. The gas leaving to 1000o F. The mixture may then be subjected separator 6 may be withdrawn through lines 1 to cracking in the presence of the catalyst in and 39 and valves 31 andv 38, or part or all of it'may be introduced into reactor I9 with the 45 reactor I0 at substantially atmospheric pressure. The product may be withdrawn through line I4, feed, through lines 1, 24 and I2, and valves 31 and fractionally distilled to obtain a gas frac and I3. In this type of operation it may _be tion, partof which is recycled through line 39, most effective to add considerable heat to the a gasoline of good antidetonation character gas during its passage through line `24, or to _ heat the mixture in line I2. 50 vistics, a gas oil which may be vaporized andre cycled to line I, and a residuum suitable as fuel Although the above methods -are preferred, oil. a third method may be employed, wherein con A gasoline or naphtha fraction may be re current flow of feed vapors and catalyst is em formed by a similar process. By operating at a ployed in reactor I0. This may be done by clos ing valves 34 and 31 and forcing the feed vapors 55 pressure of l0 or more atmospheres and using hydrogenV through line 39 rather than a light entering line i to pass down through separator hydrocarbon, a product of higher aromatic hydro 6, hopper 8 and reactor I0, leaving through line I2. In this method it is notl necessary that line _9 be a sealing leg. In fact hopper 8 may be incorporated as an integral part of reactor I0, 60 with no intervening constriction. The above processes may be employed for many types of hydrocarbon conversion, includ ing cracking, polymerization, reforming and re carbon content and lower olefln content may usually be obtained. ' In another mode of operation, flue gases at a temperature of 2000° F. to 4000° F. may be added through line 39 to give a preliminary thermal cracking at temperatures between about 1000° F. and 2000° F. to the hydrocarbons from line 1. ñning. By the term cracking it is intended to l 65 Diluents such as inert gases, recycled fractions, etc., may be added through line 32 to control include processes wherein there is a scission of the temperature of the subsequent catalytic re carbon-to-carbon bonds of the feed hydrocar action in reactor I0. ` bons, such as in conventional cracking of various The above 4operations may also-be used for the petroleum fractions, as well as dealkylation, de- , . polymerization, and like processes. By the 70 dehydrogenation of butanes to butenes, and the >further dehydrogenation to butadiene, in which term polymerization it is meant to include re processes it is advantageous to maintain a low actions involving increases in molecular weight, total pressure such as atmospheric'pressure, and such as condensation and alkylation reactions, as to reduce the partial pressure of _the hydrocarbon -well as polymerization of oleflnic material. By. in the reaction chamber to a small fraction of the term reforming it is intended to include 9,408,600 5 6 one atmosphere, such as.0.1 atmosphere or less, preferred. but pressure. differences up te .1.0 at» by the introduction Vof .inert -gases such »as .lille gas, nitrogen, steam andthe like, added through mospheres ,or `more may be tolerated .by the ‘use of‘properly ydesignen sealing :legs 'es the pres, -sure differential is increased, the-.eiîñeíeney ef the -lines I, 32, or 39. . w i ` f* ' . Refining processest such as catalytic desulfuri 5 also be carried on as above. ». seaune ieg must be increased. esfor exemple -bv lengthening .the leg. er using more »Sealing gas. The `relative amounts of feed stock, auxiliary zation Vor hydrogenation Vmay readily be car ried out according to vthe above: methods, using hydrogen as the auxiliary gas. Refining of gaso lines to remove unstable olefins andthe like may gas `and vcatalyst employed will vary with the re suits desired. `-As an example however2 .applying to the aromatization of a crude gasoline ,fraction .i at 1.000° F. and 10 atmospheres pressure, thelfeed may be introduced at a rate Qf l (liquid)- ¿volume per volume of catalyst @in reactor. Ill) ¿per hour, hydrogen may be .employed in e retin ef 3000 cubic feet per barrel of (liquid) feed, and the catalyst may be circulated at a rate -of about >0.5 In all of the above methods in which an aux iliary gas is employed, these may be introduced vinto line I instead of feed stock vapors in orderV to carry the regenerated catalyst up through yline 5, while the feed stock is introduced through ‘line 32. It is also possible to employ the concurrent volume per hour. The catalyst flow rate ¿is reg ulated largely. »by the sizeof the 4.orifice 23, `Feed, , ilow method described earlier, . `wherein sealing leg 9 is eliminated and the vapors in line '5 `are auxiliary ses. and catalyst flow4 rates between forced down through the reactor.v This method is particularly »effective when treatingv a gasoline 20 about one-tenth to ten times the above rates may be employed, yanderen Wider limits may be used to polymerize unstable gum-formingoleflns, since the polymers _formed may condense and be swept in some instances. out of the bottom'ofy the reactor. Y l l , . Outstanding features of the >process of this in. vention yas mentioned previously,;are its simplicity other ,oper -ations, however, the countercurrentfcontacting is preferred. ì Vand the use of a granular catalyst circulated by As catalysts for the cracking and reforming suspension in a flowing gaseous stream, followed by gravitational downward flow in a solid stream. operations alumina, »silica-alumina rcombinations and group VI metal oxides such as chromiumand molybdenum oxides, especially when employed with a support or carrier such as alumina or other 30 metal oxide gel and the like, are suitable. For hydrogenation operations, oxides of metals hav ing atomic numbers between 22 and 30 Tand espe cially cobalt, nickel and copper, andcombina- - tions of these with chromium, molybdenum', ti tanium, Vanadium, and the-like, as mixtures and as compounds such as chromites, molybd-ates, etc., are suitable. .These may also be employedy on carriers. For refining cracked gasolines, `active clays, bauxite, magnesia, fuller’s earth, andgvari ous oxide gels are suitable. ¿These latter _are also suitable carriers for the more active catalysts mentioned above. The invention is of course not limited to the use of the specific catalysts named. No difficulty »has been experienced in carrying granules of the above sizes _up through line 5'. For example, granules of v12 to 30 mesh have been lifted over 3_5 feet through a ,1% inch pipe VVline at a rate of about 400 pounds. per hour by a _gas stream of about rmvpounds per hour. In a variation of the process of `this invention, the regeneration chamber vI6 is placed above re actor Iû, with sealing leg 30 between and sealing leg 2| below as usual. Non-combustible inert gas with or without some air may then be introduced into line I, the obvious modifications in flow being employed. ,y In any of the above systems it is ‘apparentthat there are vmany variations which may be 1em ployed.` Fory example the cooling fluid employed in `regeneration chamber l 6 may also -be employedas „a heatingy ñuid in reaction chamber IQ. This The catalysts should be granular, preferably about 4 to20 mesh in size, although sizes between» would> necessarily involve a gaseous fluid, or pos sibly a system of flowing solids such as the cata about 1 and 60 mesh may be employed in many lyst iiow system, but would preferably be a liquid instances, and »where special bailling is employed such as a molten salt. When the cooling fluid in the reactork and‘cooler to permit countercur rent flow of the gases without suspension of the 50 i-s not also used in the reactor as a heating iiuid, water or steam could be used as the cooling me catalyst therein, smaller sizes down to about 100 dium, or the feed stock, steam, or auxiliary gas mesh may be employed. employed could be preheated by using it as the Y The reaction is preferably carried out in the cooling medium. vapor phase, as indicated, although liquid phase Although the process of this invention has been operation may also be employed, such as by in 55 ' described primarily as a hydrocarbon conversion troducing a liquid feed through line I4, allowing process, it may also be employed for shale oil it to flow down through the catalyst bed in re actor Il), and withdrawing the product through eduction, oxidation, and like processes. For oxi- ' dation, oxygen may be substituted for at least a This would necessitate maintenance of a liquid level at or just above line I2, and provision 60 part of the auxiliary gas in the above systems. For shale oil eduction, fresh granulated shale is of means such as a trap for preventing loss of added through line 21. In hopper 8 it is diluted liquid product through line 3U. ' with a controlled amount of hot recycled spent The temperatures employed for cracking are shale from line Sand separator 6, and passes into generally high, in the range of about 800° F. to 2000° F. Many of the reforming operations such 65 reactor I0 used as an eduction chamber. In re actor I0 itis heated, as by ñue gases in tube 26, as dehydrogenation and aromatization also re and subjected to stripping gas such as steam en quire high temperatures in this range, but isomer tering through line I2, the product leaving line ization and hydrogenation for example may be I4. The stripping gas may also enter line I4, and carried on at lower temperatures, down to about atmospheric. The pressures involved may range 70 the product leave through line I2 if desired to provide for simpler recovery of liquid products. from about atmospheric up to 100 atmospheres or The educted shale, which generally contains »some more, although for vapor phase operation pres carbonaceous residue even though educted at tem sures below about 20 atmospheres are preferable'. peratures of 900? F. to 1500° F. is burned in cham Operation of both the reaction and regeneration processes at substantially the same pressure is 75 ber I6, the heat being absorbed by the stripping line I2. 214085306 8 gas which enters through line I1, leaving line I8, 'and entering chamber I0 through line l2 or I4 as described. Part of this preheated stripping gas said reaction zone, regenerating said catalyst in said regeneration zone, withdrawing regenerated catalyst from said regeneration zone, suspending may also- be charged into line l to carry the de the withdrawn catalyst in a suspension gas com steam generation or the like. said reaction zone, adding to said separated sus sired amount of recycled spent shale through line 5 prising hydrocarbon feed to thereby lift said cata lyst and pass it to a separating zone, separating 5, or flue gases from line 26 may be used. The said catalyst from said 'suspension gas in said spent shale not recycled is Iwithdrawn through separating zone, passing the separated catalyst to line 28. Its heat content may be employed for The stripping gas may also be flue gas, nitrogen and the like al though hydrogen and light hydrocarbons from the product leaving chamber l0 are preferred. Other modifications of the processes of this in vention which would occur to one skilled in the art are to be considered within the scope of this invention as defined in the following claims: ‘ I claim: ' . ' 1. A process for the catalytic conversion of hy 'drocarbons which comprises ilowing a granulated catalyst downwardly by gravity through succes sive zones of reaction and regeneration, introduc ing hydrocarbons into said reaction Zone and maintaining an elevated conversion temperature -therein while said hydrocarbons flow through said reaction zone countercurrently to said flowing catalyst, regenerating said catalyst in said re generation zone, withdrawing regenerated cata pension gas ñue gases having a temperature be tween about 2000° F.> and 4000" F. so as to give a preliminary thermal cracking `to said hydro carbon feed at a temperature between about 1000° F. and 2000° F., and passing the resulting gaseous mixture through said reaction zone countercur rently to said flowing catalyst. 6. A process according to claim 5 in which the catalyst granules are between about 4 and 20 mesh in size. 7. An apparatus for the catalytic conversion of hydrocarbons _which comprises a reactor and a regeneration chamber so connected and arranged that granulated catalyst may ilow by gravity suc cessively through said reactor and regeneration chamber, means for introducing catalyst into said reactor, means for introducing a gaseous mixture into said reactor to pass countercurrently to said catalyst, means for maintaining an elevated tern perature in said reactor, means for regenerating withdrawn catalyst in a suspension gas to thereby said catalyst in said regeneration chamber, means lift said catalyst and pass it to a separating zone, 30 located near the bottom of said regeneration separating said catalyst from said suspension gas chamber for controlling the rate of flow of cata lyst from said regeneration Zone, suspending said in said separating zone, passing said separated catalyst to said reaction zone, and introducing said separated suspension gas into said reaction _zone with said hydrocarbons. 2. A process according to claim 1 in which the suspension gas comprises hydrocarbon feed, ` p V3. A process according to claim l in which the suspension gas comprises hydrogen. lystrthrough‘said reactor and said regeneration chamber, outlet means for removing said catalyst from said regeneration chamber, separating means positioned above said reactor for separat ing gases from catalyst, means connecting said outlet' means ‘with said separating means, means for introducing a suspension gas into said con 4. A process according to claim 1 in which the 40 ‘nesting’ means to thereby suspend said catalyst in suspension gas comprises light hydrocarbon gases. 5. A process for the catalytic conversion of hy drocarbons which comprises flowing granulated catalyst downwardly by gravity through succes sive Zones of'reaction and regeneration, main 45 taining an elevated conversion temperature in said suspensiongas and lift said catalyst into said separating means, and means for introducing sus pension gases separated in said separating means into said reactor together with said gaseous mixture. " _ CLYDE H. o. BERG.