CA1047427A - Ebullating bed process for hydrotreatment of heavy crudes and residua - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A process for the hydrotreatment, or hydroconversion, of heavy crudes and residue in an ebullating bed of catalyst, expanded to critical volume ranging from about 20 to 70 percent, of its settled volume, wherein the catalyst particles are metallized or coked, or both, and segregated on a weight basis and the heavier, more aged and inactive catalyst is collected and removed from the bottom of the bed, while fresh catalyst or precatalyst is added to the top of the bed. The ebullated bed can be staged in one or more initial reactors of a series, product therefrom being fed to a subsequent ebullated or fixed-bed reactor, or reactors. The ebullating bed reactor, or reactors from which the segregated aged catalyst is removed can be employed in series or in parallel.

Description

10474~7 1 Proce~ses for the treatment of hydrocarbon feed-

2 stocks, particularly the catalytic hydrotreatment of such

3 feedstocks, with hydrogen, eOgO~ hydroforming, hydrocrack-

4 ing, hydrofining, hydrodesulfuriz~tion, and the like, are well established in the petroleum refining industryq The 6 hydrotreatment of heavy crudes and residua9 ~n particular, 7 is also well known and~ despite the difficultie~ associated 8 with the treatment of such materials9 con~iderable emphasis 9 has been recently placed on the development of hydrodesul lo furization processe~ because of environmental considerations 11 which make it imperative to remove ~ulfur from ~uch materials 12 before they can be used a~ fuels 13 Heavy petroleum crudes ~nd re6idua contain con-4 siderable a unts of heavy oil89 resin~9 nondistillable a~phaltenes (iOeO, pentane insoluble asphaltenes)~ or high 16 molecular weight coke precursors, and the like, and these 17 contain high nitrogen, sulfur oxygen and metalloorganic 18 complexes, or metal contaminants which9 when sub~ected to 19 heat, coagulate~ polymerize, or decompose and create mate-rials difficult to further proces30 In the past, the 21 lower molecular weight or gas oil portion of such feedstocks 22 has béen catalytically converted and upgr ded to high value 23 fuels, while the heavy ends or 1050Fo+ materials were 24 split out, then generally used as low grade fuel or as as-phaltic material. ~ -26 Processes are known for the catalytic hydrocon-27 version of whole crudes or feeds which contain 1050F~+
28 hydrocarbon mdterials, in which processes the 1050F~+
29 material is converted into 1050Fo~ materialsO In the H-oil proces~ described, eOg~ in Johanson's UOS. 2~987~465 31 (Re. 25,770), an ebullating bed process is described wherein 32 hydrogen and a hydrocarbon feed are reacted in a reractor, or ~'`

~ 2 -. .
. ~

.
l reactor system~ ~uch that $clid c~taly~t particle3 are 2 maintained in a ~tate of continuou~ random motion by upo 3 fl~w of the liquid pha~e~ T~e prcce~ in one or more 4 stage~ (UOSo 397059849)~ is t~u~ conduc~ed under condition3 which establi~h a random mction of ~he cataly~lc particles 6 in the liquid without the solid~ being carried ou~ of a 7 reactor~ There is con~iderable bac~=mixing of the ~olids 8 from top~to~bcttom within the reactorO Ba$ed cn the ~olid 9 ~ize and density of the eataly~t p~rticle$~ and liquid den~
sity~ velccity and vi~co~ity~ the ~ of p~rticulate 11 solid~ i~ generally expanded from ibout lO percent greater 12 volume than the settled state of the ma~ to 3bcut 100 per~
13 cent~ or twc or three time~ the ~et~led volumeO
14 While an ebullat~ng bed proce~ ha~ been found S u~eful in the treatment of ~uch feed~ it nonQthele~ ha3 16 certain limitations. Thus9 there are cer~ain di~advantages 17 a~sociated with the rapid lo~ of activity of the cat~lyst 18 used in 8~ch proce~s. For example9 in proce$$ing residua9 a 9 tarry9 st~cky material i8 formed upon and apparently ~b-sorbed by the cataly~t particles9 thi~ all too rapidly foul 21 ing the catalyst. Metal~ from the feed depo~it upon9 clog9 22 and clo~e the pores of the cataly~t. Coke and other carbon~
23 aceous materials al~o depo~it upon the cataly~t w~th ~imilar 24 resultsO Conglomeration of the cataly~t par~icles produces channelling and lowering of cataly~t perfonmance. The cata 26 lyst becomes aged9 and its activity is thu~ decreasedO It 27 is therefore nece~s~ry to replace the fouled cataly~t with 28 fresh or regenerated cataly~t~ thi~ being accompllshed in 8 ~ continuous proce~ by constant addition of fre~h or regenera ted catalys~ with accumulation dnd continuous withdrawal of 31 the spent catalyst. The spent c~taly~t9 if regenerated, may 32 be reintroduced as a slurry into the reactor. Where~s con-1 tinuous catalyst rem~valD and con3tant repla¢ement of aged 2 catalyst with fresh or regenera~ed cQtaly~g i~ highly bene-3 ficial in thst pro~ess con~itions can be bett~r ~ptimized 4 vis-a~vis a similar process run continuously and then peri-odically shut down for repla~emen~ of aged ca~alys~ wi~h 6 fresh or regenera~ed ca~alys~9 ~he opera~ion is less effi-7 cient than desired because it is necessary to rem~ve cata~
8 lyst from ~he reactor for replacement before ~t has reached 9 an optimum age. Thi8 iS due ~o ~he considerable ~urbulence . ., and top to~bott~m mi~ing of ~he ca~alys~ solids which pro~
11 duces an es~entially hQmogenous catalyst phase. This9 of 12 cour~e9 necessitates remaval of catalyst from ~he reactor i/~
13 before it has reached an opt~mNm age9 this requiring opera-14 tion of the reactor at higher severities and lower effici~
ency than desirable. This9 of cou~e9 also increases capi 16 tal co8t~9 and the cost of maintenanceO - -17 An impending energy crunch will require use of 18 all available energy resources9 including the use of ~ncon 19 ventional materials such as Athaba~ca tar sand~D Canadian and Venezuelan heavy tar~. These ~o~called 1050Fo+ heavy 21 crude~ are different from conven~onal heavy crudes in at 22 least four important aspects9 each of which makes hydrocon~
23 version of such crudes by present me~hods en~irely unfeasi-24 ble--viz., ~hey ha~e (1) very high Conradson carbon (i.e., 25 "Con carbon") or carbon~o~hydrogen ra~los ~i.e.l rela~ively ~ -26 high carbon and low hydrogen content)9 ~2~ very high me~als 27 content, partieularly as regards the amount of nickel and 28 vanadium, (3) they are ultra~high in ~heir content of ma-29 terials boiling above 1050F.9 e.g.D asphal~enes, and even (4) contain consider~ble amounts of sand and scale. Pro-31 perties which readily distinguish these new materials from 32 conventional crudes are thuso high metalsD hlgh asphaltenes, 1047~Z7 1 high carbon~hydrogen ratios9 and a high vol~me percent of 2 hydrocarbons bciling abcve 1050F. The pre~ence of the 3 greater amounts of metals and the higher carbon content of :~ 4 the heavy crudes9 in partl¢ular9 makes any conslderations regarding the process~ng of ffhese materials most diffieult 6 and expensive. The high carb~n~hydrogen ~i.e.9 Con carbon) 7 ratios are considerably higher than that of a~ presently .. 8 usable hydrocarbon liquids.
9 Due to these considerations~ an ebullating bed process does offer certain ~d~antages ~ver flæed bed pro : 11 cesses. For e~ample, tbis type of pro~ess permits th~ use 12 of relatively active catalysts of small partlcle size9 which 13 would be e3sentially inoper~ble in a fixedobed d~e to ex~
14 cessive pressure drop. More~verD since the bed of such type of process is not f~xed9 the presence of fines solids 16 partlcles such as occurs in many he~vy crudes and residua 17 does not readily plug the rea¢tor. The ebull?ting bed sys-18 tem ~180 provides Yery efficient cat~lyst~liquid contact9 19 while prcvidlng an isotherma~ en~ironment for ve~y highly exothermic xeactions. It a~levliates m~y pr~blems associ~
21 ated with ~he heat release w~ich occurs in ~ydrogenation 22 re~ctions9 ~lbeit the ~urbulence and top to~bottom mixing 23 of the catalyst of continu~usly ~perated con~en~ion~l ebul-24 lating bed processes prevents optimization of catalyst age.
Hence9 an improved process of such type migh~ mske feasible 26 an operat~on which could utilize very heavy9 dirty9 uncon~
27 ventional feeds.
28 Scme advancement has been achieved in improving 29 the oper~bility of ebullated bed systems~ but most yet fall short of improving operability to ~he desired level in pro~
31 cessing the high metals containing crudes and residua. This 32 is becau~e the metal8, generally vanadium ~nd nickel, rapidly 10474z~
1 poison and de~cti~ate t~e cataly$t~ and in multi~bed systems 2 the cont~minated cataiyst is t~us all ~oo readilg carried 3 cver to subcequent ~tages~ re~ulting in a cæntinucus buildup 4 of contaminated catalyst.
An ob~ect of the present invention i9 to provide 6 new and ~mproved ebullat~ng bed proces~D especially an ebul-, . . .
7 lating bed hydro~rea~ing processD no~ably a ~ydrodesulfuri~ :
. 8 zation or hydrocarbon co~ver~on process9 useful in process-9 ing crude and residua w~ich con~ain 1050F.+ hydrocarbons.
Thls ob~ect and other3 are achieved in accordance 11 with the pre~ent process for the catalytic ~ydrotreabment 12 of hydrocarbons9 part~cularly he~vy crudes and re31dua, 13 within a reaction zone containing a bed of catalys~ solids -. :
14 particles~ L~w density solids particles are added to an . 15 upper portion of the bed, and the cataly~t p~rticles which . 16 form the bed are ebullated during the reaction by upflow of il 17 liquid and the bed expanded to a volume ranging from about 18 20 to about 70 percent, preferably fr~m about 30 to about 19 50 percent9 a~ contrasted with the volume of the s~me bed - 20 when the catalyst particle~ thereof are in quiescent state, 21 and solids catalyst particles of hig~ densi~y are wi~hdr~wn 22 from the bottom of the bed.
23 In accordance with a preferred embod~ment of the 24 present invention, a bed of so~ids ca~alyst par~icles is established, or formed, within a reaction zone9 low density 26 solids particles are introduced con~inu~usly or intermit- -27 tently into an upper portion of the bed9 while during the 28 reaction the bed is ebullated by upflow of a metals~con- ::
29 taining liquid feed introduced, wi~h hydrogen, into the bed at velocities sufficient to e~pand the bed to a volume 31 ranging from about 20 to about 70 percentD preferably from 32 about 30 to about 50 percent, providing during the reaction -; ~0474Z7 .- 1 sufficient agita~ion.of the solids par~i~les ~o produ e a 2 graded separation of the solids cat~lyst particles from the : 3 top to the bottom of the bed9 the gr~dlent belng established 4 such that low densi~y par~icles are located a~ t~e top of the bed while high density par~isle~ are loca~ed a~ ~he bot-6 tom of the bedg and high density cata~yst particles are 7 continuously or inte~mittently withdr~wn from the bottom of 8 the bed.
9 A key and novel fea~ure of the invention resides in the na~ure of the l~w density solids parti¢les intro~
11 duced into the ebullated bed9 and in the catalyst maintained 12 wi~hin the ebullated bed. The low density solids particles, 13 a catalyst or precatalyst3 at ~he ~ime of ~ni~ial in~roduc-.
14 tion into the bed are thus of critical pre~selected pore I5 size distributions9 extremely low den~ity9 and ultra~high 16 porosity, such that as the reac~ion proceeds the density of 17 the solid~ particles is progreqsively increased par~ially 18 by coke buildup on the c~talystJ bu~ principally by ~he ab-19 ~orption of me~als9 the catalyst or prec~t~lyst absorbing - 20 fr~m the feed sufficient of the me~ls to increa~e the 21 weight of the catalyst as much as 50 tc 300 percent9 and 22 higher, (based on ~he original weight cf the catalyst~ and 23 within the preferred regime of impo~ed conditions as much 24 as 100 to 200 percent of metal~ from the me~al~containing feed (particularly nickel and vansdium~ as reaction proceeds, 26 the density o-f the particles ~hereby increasing whichg with 27 the conditions established9 enable particle segrega~ion by 28 a density gradient which ranges from lowe~t density at the 29 top of the bed to highest density at the bottom of the bed.
By establishing such gradient, aged~ and consequently the 31 most inactive, catalyst can be withdrawn from the bottom of 32 the bed.

1 The low densi~y solids parti~les charged to the 2 ebullating bed is a catalyst9 precatalyst sr catalyst pre~
3 cursor, preferably a catalyst whi~h already contAlns all or 4 a portion of the desired hydrogenat~on~dehydrogenation or metal componentsO The low density so~ids are ~hus generally 6 and preferably preformed catalysts~ or catalysts which are 7 comprised of metals in catalytic amounts composited with an 8 inorganic oxide support9 preferably aluminaO ~owever, a 9 support per Re9 or a ~upport which contains relat*ely small amounts of a cata-ytic metal9 or metals9 can also be added 11 to an ebullated catalyst bed and a cataly~t fo~med In situ 12 from catalytic metals contained within the feed as ~he re-13 action proceeds. Nickel9 a ccmmon cont~minating metal found 14 in heavy crudes and residua, i~ ~kus a known ca~alytic -metAl9 and it can be added ~o such support9 or support which 16 already contains only a small ~mount of the same or a differ-17 ent catalytic metal~ or metals9 to fonm the catalyst in situ 18 during reaction. Nic~el is thus deposi~ed wi~hin ~he rela-19 tively large pores cf ~he low density ~olids to provide the required hydrogenation-dehydrogenation function9 alone or 21 in combination with another previously inoorporated metal, 22 or metalsO
23 The preferred low density catalysts of this inven-24 tion are characterized ~s catalysts w~ich comprise ca~aly~ -tically active amounts of a hydrogenation component which 26 includes a Group VIB or Group VIII me~al ~especially a 27 Group VIII non~noble metal)9 or both ~Perlcdic Table of the 28 Elements, E. H. Sargent and Co-9 Copyri~h~ 1962 Dyna-Slide 29 Co.), par~icularly molybdenum or ~ungs~en of Group VIB, and cobalt or nickel of Group VIII9 and preferably a Group 31 VIB and Group VIII metsl in admixture one metal with the 32 other, or with other metals9 or both9 particularly Group .

"~
1 IVA metalsg composited with a refractory inorganic s~pport, ';t~; 2 notably a porous inorganic oxide support3 particularly 3 alumina, or more particularly gamma alum~n~.
4 The metals of the catalysts genera~ly ex~st a~ _ S oxidesD sulfides, reduced forms of the meta~ or as mixtures ."
6 of these and other forms. Suit~bly, the catalyst composi-7 tion cGmprises from abou~ 5 to about S0 percent9 preferably 8 fr~m about 15 to about 25 percent (as the oxide) of the 9 Group VIB metal9 and from about 1 to about 12 percent, pre~
ferably from about 4 to about 8 percent (as the oxide) of 11 the Group VIII me~al5 based on the ~otal weight ~dry basis) 12 of the composition. The preferred act~e metallic compo-13 nents9 and forms thereof9 comprise an oxide or sulflde of 14 molybden~m and tungsten of Group VIBD an oxide or sulfide of nickel or cobalt of Group VIII9 preferably a mixture of 16 one of said Group VIB and one of said Group VIII me~als, 17 admixed one with ~he other and incluqive cf third metal 18 components of Groups VIBa VIII and o~her metals9 particu~
19 larly Group TVA metals. The most preferred catalyst is constituted of an admixture of cobal~ and molybdenum, and 21 in some cases nickel and molybdenumO Other Group VIB and 22 VIII metals include9 for example9 chr~iumD pl~tinum, 23 palladium9 iridium9 osmium, ruthenium9 rhodium9 and ~he 24 like. The inorganic oxide supports suitably comprise alumina, silica9 zirconia, magnesia9 boria, phosphate, 26 titania, ceria, thoria, and ~he like. The ca~alyst compo-27 ~ition can be in the form of beads9 aggregates of various 28 particle sizes, extrudates9 tablets or pelletsg depending 29 upon the type of process and condi~ions ~o which the cata-lyst is to be exposed.
31 Particularly preferred catalysts are composites 32 of nickel or cobalt oxide with molybdenum used in the fol-, 10474z7 1 lowing approximate proportionso fr~m about 1 so about 12 2 weight percent9 preferably fr~m about 4 to ~bout 8 welght 3 percent of nickel or ccbalt oxides, and fr~m about 5 to 4 about 50 weight percent9 preferably fr~m about 15 to about 25 weight percent of molybdenum ox~de on a suitable support 6 such as alumina. The catalyst i3 sulfided to fo~m the most 7 active species.
8 The Group VIB and Group VIII meSal components9 9 admixed one component with the other or with a thlrd or greater number of metal c~mponentsJ can be campo~ited sr 11 intimately associated with ~he porous inorganic oxide sup~
12 port or carrier by v~rious te~hniques kn~wn to the art9 such 13 as by impregnaticn of a support wi~h the metals~ ~on ex~
14 change9 coprecipitation of the metals with the alumina in the sol or gel form9 and the like. For example9 a preformed 16 alumina support can be impregnated by an "incipient wetness"
17 technique9 or technique wherein a met~lD or metalsg is con-~8 tained in a ~olution in measured amount ~nd ~he enti~e so-l9 lution is absorbed into She support which is then dried9 calcined9 etc.9 to form t~e catalyst. A1SOD for example9 ~he 21 catalyst camposite can be formed fr~m a cogel by adding to-22 gether suit~ble reagents such as salts of the Group VIB or 23 Group VIII metals, or mixture~ of these and other metals, 24 and ammonium hydroxide or ammonium carbonate9 and a salt of aluminum such as aluminum chloride or al~minum sulfate to 26 form aluminum hydro~ide. The aluminum ~ydroxide containing 27 the salt~ of the Groups VIB or Group VIII metals, or both, 28 and,~dditional metals if desired can ~en be heated, dried,;
29 formed into pellets9 or extruded, and ~hen calcined in ni-trogen or other generally nonreactive or inert a~mosphere.
31 Catalysts formed from cogels do not posse~s pore size dis-32 tribution as uniform as those formed by impregnation methods.

-- ~, , '. ' :

10474~7 1 The more preferred oataly~s of ~hls ~n~ention 2 further c~mprise a metal9 or met~ls9 o Gr~up T~A9 or c~m~
3 pounds thereofO ~he ca~.~ly~t.~ will ~hus c~mprise germanium9 4 tin9 or leid9 or ~dmixture of such me~als with each cther or with o~her me~alsD or bo~h9 in c~mbina~ion wi~h ~he Group 6 VIB or Group VIII metals9 or admlxture ~hereof. The Group 7 IVA metals act as promoters ~n enhanc~ng the ra~e of deme~
8 tallization of a feedO Of the Gro~p ~V~ metals9 germanium 9 is partlcul rly preferred. Suitab~e~ ~he Group I~A met~
comprises from about 0~01 to about 10 perc~nt9 prefer~bly 11 fr~m about 2.0 to ab~ut 5 percent of the cat lyst9 based on 12 he total weight (dry basis~ of ~he ccmpo ition. The Group 13 IVA metals must be incorporated wi~hln ~he cataly~t by ~m~
14 pregnation.
The cataly~t9 catalyst preeursor9 or preoatalyst 16 also include a combination of properties o~mpris~ng at least 17 about 50 percent~ preferably t least ~bout 75 percent9 of 18 its total pore volume of absolute di~met~r within the range 19 of about 100~ ~Ang~træm ~n~tB) to about 300~9 preferably fr~m about 20~A to about 300A9 and les~ ~han about 20 per-21 cent~ preferably less than 10 percent of lt~ total pore 22 volume of ~bsolute diameter within the range of 0 to loOA9 23 a surface area ranging t leas~ 3bou~ 200 m2~g ~o abou~
24 600 m2/gS and preferably at least abou~ 250 m2~g ~o about 450 m21g~ and a pore volume ranging fr~m ~bou~ 0.8 ~o about 26 3.0 ce~g~9 and preferably from abou~ 1~1 to about 1.9 cc/g 27 (B.E.T.~.
28 ~he following is a tabulation of pore size dis~
29 tributions9 as percen~ of ~o~l pore volume9 of preferred catalysts9 catagyst precursor9 or preca~alyst according to 31 this invention~

~ 11 -, Distribution of More Pore Diameters (1) Preferred Preferred 0-1001. <10% < 5%
200-300A >50% ~75~
400A+(2) ~20% ~10%

(1) Measured by nitrogen adsorption isotherm, wherein nitrogen adsorbed is at various pressures. Technique described in Ballou, et al, Analytical Chemistry, Vol. 32, April 1960, using Aminco Adsorptomat r(Catalogue No. 4-4680) and Multiple Sample Accessory (Catalogue No. 4-4685) Instruction No.
861-A~ which uses the principle of adsorption and desorption of gas by a catalyst specimen at the boiling point of nitrogen.
(2) Not essential, but desirable.
The catalysts, catalyst precursors, or precatalysts charges to the ebullating bed range in particle density, dry basis (measured by mercury intrusion method; American Instruments 60/800 Porosimeter), from about 0.25 to about 0.7 gm/cc, and preferably from about 0.4 to about 0.6 gm/cc, dependent in large measure on the weight of metals, if any, contained within the catalyst. Catalysts with added metals are, of course, of greater density ab initio than catalyst precursors which contain little or no added metals. The particle densities of the catalysts removed from the bottom of the bed range generally from about 0.35 to about 2.1 gm/cc, and within the preferred regime of imposed conditions from about 0.55 to about 1.1 gm/cc, or even 1.5 gm/cc if the catalyst also contains considerable coke in addition to absorbed metals. Preferably, the gradient estab-lished between the top and bottom of the ebullating bed, in terms of the difference in particle density, ranges at least about 0.1 g/cc, preferably from about 0.2 to about 0.6 gm/cc, and more preferably from about 0.3 to about 0.5 gm/cc. The catalyst - :
,~', , , ' , :
, : ' 10474~7 usually ranges in size from about 1/16 inch average diameter, and smaller, generally within a range of from about 100 to about 1400 microns.
The required ebullation of the particulate catalyst is maintained by introducing the liquid feed, inclusive of recycle, if any, to the reaction zone at linear velocities ranging from about 0.02 to about 0.3 feet per second, and pre-ferably from about 0.05 to about 0.15 feet per second. This rate of feed addition, which is not significantly affected by the normal rates of hydrogen addition, maintains the necessary volume of bed expansion, provides adequate oil and catalyst eontact to assure effieient operation, and yet provides the desired eatalyst partiele segregation by weight so that the aged eatalyst ean be withdrawn from the bottom of the bed, with signifieant admixture of the more aged eatalyst with eatalyst of lesser age.
The present proeess, which embodies an ebullating bed permitting seleetive bottom removal of metals loaded eatalyst, is partieularly suitable for proeessing, in an initial or first reaetion zone eomprising one or more stages (and in one or more reaetors), a whole heavy erude or residua eontaining 1050F. +
materials, espeeially feeds having the following eharaeteristics:

Operable Preferred Range Range Gravity, API -5 to 20 0-14 Heav~ Metals (Ni & V), ppm 5-1000 200-600 1050 F.+, Wt.% 10-100 40-100 Asphaltenes te5 insoluble), Wt.% 5-50 15-30 Con Carbon, Wt.~ 5-50 10-30 30 which can be contacted in the presence of hydrogen at severities suffieient to eonvert at least about 30 pereent by weight and , ' '. ~ ~ . ' ~ .
' ' . ' : ~ :
.

.
- -~0474Z7 preferably from about 40 percen~ to about 60 percent of the 1050 - F.+ materials of the crude or residua present to 1050F.- materi-als, remove at least about 75 percent, and preferably from about 80 to about 95 percent, by weight of the metals, preferably producing a product having the following characteristics:

Operable Preferred ;; Range Range Gravity, API 14-30 15-25 Heav~ Metals (Ni & V), ppm 10-100 40-80 1050 F.+, Wt.~ 10-50 25-40 Asphaltenes (C5 insoluble), Wt.~ 3-20 5~15 ;~ Con Carbon, Wt.% 3-20 5-10 . .
In conducting the reaction in said first reaction zone, the major process variables, tabulated for convenience, 15 are within ranges characterized as follows:
Operable Preferred Temperature, F. E.I.T.(l) 650-850 700-800 ;~ Pressure, psi 500-10,000 2000-5000 Hydrogen Rate, SCF/B 3000-20,000 3000-10,000 ; 20 Space Velocity, LHSV 0.2-3.0 0.5-1.5 (1) Equivalent Insothermal Temperature (E.I.T.) The product of said first reaction zone is suitable for further contact, in the presence of hydrogen, in a second or subsequent reaction zone comprising one or more stages (and in one or more reactors) in fixed beds, moving beds, or additional ebullating beds with the same or a different catalyst, or cata-lysts, at severities sufficient to convert at least about 50 - percent, and preferably from about 60 percent to about 75 percent of the 1050F.+ materials of the crude or residua to 1050F.-materials, remove at least about 90 percent, preferably from about 97 percent to about 100 percent, by weight of the metals of the feed (i.e., the product of said first reaction zone), and reduce ,' - . ~ , :

10474Z'~

Con carbon from about 50 percent to about 100 percent, and pre-ferably from about 75 percent to about 90 percent, especially to produce a product having the following characteristics:
Operable Preferred Range Range Gravity, API 18~30 20-28 Heav~ Metals (~i & ~), ppm ~50 ~5 1050 E.+, Wt.% 5-30 10-25 Asphaltenes (C insolubles), Wt.% C3 <1 Con Carbon, Wt.5~ <5 ~3 A preferred second reaction zone catalyst is one of composition similar in all respects to that heretofore described with regard to that suitable for use in said first ; reaction zone, but of somewhat different physical characteristics, particularly that of small pore size distribution. Such catalyst generally comprises at least about 55 percent, and preferably at least about 70 percent of its total pore volume of absolute diameter within the range of about 1O0A to about 200~, and less than about 30%, and preferably less than 15% of its total pore volume of absolute diameter within the range of about 20~ to about 100~, a surface area ranging from about 200 m2/g to about 550 m2/g, and a pore volume ranging from about 0.6 to about 1.5 cc/g, and preferably from about 0.8 to about 1.2 cc/g (B.E.T.) The following tabulation shows the pore volume distributions, as percent of total volume, of preferred second reaction zone catalysts:
Distribution of More Pore Diameters (1) Preferred Preferred 20A to 100A ~ 30~ <15~
lo0R to 200A > 55~ > 70%
200A to 400~ < 15~ ~ 15%

,,- : - ,, , ' .- -'''"

' ~ , , .

10474Z'~
(1) Measured by nitrogen adsorption isotherm, wherein nitrogen adsorbed is at various pressures. Technique described in Ballou, et al, Analytical Chemistry, Vol. 32, April 1960, using Aminco Adsorptomat C(Catalogue No. 4-4680) and Multiple Sample Accessory (Catalogue No. 4-4685) Instructions No. 861-A~ which uses the principle of adsorption and desorption of gas by a catalyst specimen at the boiling point of ~itrogen.
The invention will be more fully understood by refer-ence to the following selected nonlimiting examples which illus-trate its more salient features. All proportions and parts are given in terms of weight except as otherwise specified.
EX~PLE 1 A run was conducted by passage of a liquid hydro-carbon feed into the bottom of a tubular vessel, in which was initiallycharged 300 parts by volume of a catalyst of partiele size ranging from 18-20 mesh (Tyler) comprised of ; 6.0% eobalt as CoO and 24% molybdenum as MoO3 eomposited on an alumina support. Alumina having a particle density of ;20 0.92 gm/cc and a particle size distribution ranging 18-20 mesh (Tyler) was eharged via an inlet into the tubular vessel into the top of the ebullated bed. The eharge was adequate to provide 30 parts by volume alumina, or about 9 percent by weight of the total particles constituting the ebullating bed. At the temperature and pressure of opera-tion, the hydroearbon feed had a viseosity and density approximating 0.30 centipoises @ 80F. and 0.680 gm/cc, respectively, and the feed was introduced at a velocity - 16 - ~ -::

:
.

10474f~'7 1 of approximately 0.063 feet per ~econd linear velocity 2 providing an ebullating bed expanded to 35% greater volume 3 than the vclume of the ~me bed in quiescen ~tate. At 4 these conditions of operation9 a catalyst havlng a particle density approximating 0.8 gm~cc was withdrawn from the 6 bottom of the tubular vessel.
7 Pur~uant to ~hese conditlons of operation~ it was 8 found that particle~ approximating the density of the alu-9 mina cat~lyst charge9 i.e.9 0.65 gm/cc9 remained within the top of the ebullating bed~ Particle~ of density approxi 11 mating 0.92 gm/cc were concentrated within the bottom 23-12 25% of the expanded ca~alyst bed, and the high density par-13 ticulate withdrawn from the bo~om of the bed was approxi-14 mately 0.8 gm/cc.
In sharp contrastD w~en the liquid velocity into 16 the tubular vessel was raised sufficient to further expand 17 the bed to 71%9 as eontrasted with the volume of the bed in 18 quiescent state9 but otherwise operated in ~imilar manner, 19 all of the particulate material within the vessel became well distr~buted within the bed9 a high degree of mixing of 21 the he~vier particles occurring particularly within the 22 lower 70% of the bed~

24 A heavy liquid petroleum, as characterized in Table I, below 27 Gravity9 API 8.6 28 Heavy Metals (Ni &V), ppm 480 29 1050F.+, Wt.% 49 Asphaltenes (Cs insoluble), Wt.% 17.7 31 Con Garbon, Wt.% 13.8 32 is fed, wlth hydrogen, into a reactor at a liquid flow velo-33 city of about 0.067 feed per second, to exp~nd a bed of cobalt-.

~ 0474Z'7 molybdenu:~/al~smlna cataly~t9 Table II, bel~w, to 4070 of its 2 original vo~ume, , 4 C~09 Wt~% 6~0 MoO39 WtoX 2400 6 Surface Are~9 m2/g 330 ; 7 Pore Vol~me9 cc/~ 106 8 Par~icle Density, gm/cc 0065 9Distribution of Pore Diame~er3 l, 10 0-100~ 7 : 11 10~20~A 20 12 200~300A 65 13 40QA~ 8 14 the reac~ion being operated at condi~ions described ln Table III9 belowo . 16 TAB~ III
17Te~perature9 Fo ~Eo I oTo ) 18 StartoofRun 750 19 Endoof~Run 800 Pre~ure~ p~i 2200 21 Hy~rogen Rate, SCF/B 6000 22 Space Velocity/ LHSV
23 Duri~g ~he reaction, a liquid effluent as characterized in 24 Table IV, below, i~ taken from the reactor and further treated at the conditions 26 Temperature~ F. (E.I.T.) 27 Start~of~Run 650 28 End~of~Run 775 29 Pressure, p3i 2200 Hydrogen Rate, SCF/B 6000 31 Space Velocity, LHSV

- 18 o ~0474Z7 ~ABLE IV
2 Gr~l~ity9 AlDI 18 0 6 3 Heavy Met~ls (Ni ~ V~3 ppm 50 :~ 4 1050Fo~9 Wt:.~ 30 Asphaltenes (C5 insoluble~Wt.% 502 : 6 Con Carbon9 W~ 400 7 A cataly8t9 characteri~ed in the following Tsble 8 V, Is c~n~in~ou~ly or intermittently withdrawn from said 9 reactor.
~ABLE V
11 Cc~S~ W~% 201 12 MoO39 Wto% 8 o ~ ~ .
13 NiS9 Wt.% ~05 14 V2S39 W~.% 2808 - 15 Carbon9 Wt.% 31.4 16 A120~ 24.0 -17 Particle Dens~y9 gm~cc 1008 . . . .
18 EXAMPLE 3 :
: lg Further simulation of the data show~ that the effluent fr~m ~he reactor de~cr~bed ~n Example 2 can be 21 further treated~ as follows~
22 A cobalt~molybdenum/alumina catalys~ such as 23 characterized in Table VI below c~n be continuously or 24 intermittently charged via an inle~ ~nto the top of an ebullating bed of a second reactor of a ~erie~, into the 26 bctt3m of which i8 fed, with hydrogen~ the effluent from ~-27 the fir~t stage reactor described by reference to Example 2.

.

10474~7 ~ 1 TABLE VI
2 ~09 W~ o% 600 3 N~D3~ Wto~ 2400 . 4 Surface Area9 m2/g 340 Pore Volume9 cc/g loO
6 Partiele Den~ltyD gm/cc 0O7 : 7 D~stribution of Pore Di~meter~ :
8 OolO ~ 5 9 ~Loo~200A 8s - lo 2000300A g 11 400A+
12 The effluent9 or feed to the bottom of said ~econd reactor, ,: 13 provides 40% bed expansion~
14 The reactlon i8 conducted at the conditions described in the following Table VII.
16 T~BLE VII
17 Temperature~ F. (EoIDTo~
18 Start~of~Run 700 19 End~of~n 800 Pressure9 psi 2200 21 Hydr$gen Rate9 SCF/B 6000 22 Space Velocity9 L~SV Or5 23 The c~talyst continuously or intermittently re-: 24 moved from the bottom of said second stage reactor is iden-tified in Table VIII9 belowOo 10~4Z7 .....
2 CoS9 Wt.% 3O0 3 MoS29 Wt.~ 11.9 4 NiS3 ~t.~ loO
V2S39 Wto% 4.2 6 Al2039 Wt.% 34.5 7 Carbon, W % 45~5 8 Particle Den~i~y9 gm~cc 1.06 ;9 The effluent from said second reactor i~ charac-terized ~n Table IX9 belowo 12 Gr~vlty9 API 23.0 : :~
13 Heavy Metals (Ni ~ V)9 ppm ~S :
14 1050F.~ Wt.% 10.5 Asphaltenes (C~ insoluble)9~tO% ~0.5 16 Con Carbon9 Wt.% 1.0 17 It is apparent ~hat various modifications and 18 changes can be made with~ut departing the spirit and scope 19 of the present invention.

~ 21

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a process for the hydrotreatment of heavy crudes and residua which contain large quantities of 1050°F.+ hydrocar-bon materials in an ebullating bed of catalyst operated at condi-tions wherein the catalyst particles are metallized or coked, or both, particles are added to the upper portion of the ebullating bed and catalyst withdrawn from the bottom of the bed, the im-provement comprising:
establishing a bed of catalyst solids particles and ebullating said bed by upflow of a metals-containing liquid hydro-carbon feed introduced, with hydrogen, into the bed at velocity sufficient to expand the bed to a volume ranging from about 20 to about 70 percent, as contrasted with the volume of the bed of catalyst wherein the particles thereof are in quiescent state, introducing a catalyst or precatalyst comprising at least about 50 percent of its total pore volume of absolute diameter within the range of from about 100.ANG. to about 300.ANG., and less than-about 20 percent of its total pore volume of absolute diameter within the range of 0 to about 100.ANG., a surface area ranging at least about 200 m2/g to about 600 m2/g, a pore volume ranging from about 0.8 to about 3.0 cc/g, and a density ranging from about 0.25 to about 0.7 g/cc, into the top of the ebullating bed, conducting the reaction at conditions within ranges characterized as follows, Temperature, °F. (E.I.T.) 650-850 Pressure, psi 500-10,000 Hydrogen Rate, SCF/B 3000-20,000 Space Velocity, LHSV 0.2-3.0 to produce stratification and grading of catalyst particles as a result of increased density caused by absorption of coke or metals, or both, in direct relation with catalyst age, the more aged catalyst particles settling to the bottom of the ebullating bed, and removing catalyst from the bottom of the ebullating bed characterized as containing a composite of from about 5 to about 50 percent of a Group VIB metal, or compound thereof, from about 1 to about 12 percent of a Group VIII metal, or compound thereof, or admixture of said Group VIB and Group VIII metals, or compounds thereof, measured as oxides, a po-rous inorganic oxide support, and having a density at least about 0.1 g/cc greater than the density of the catalyst or precatalyst added to the top of the bed as a result of having absorbed metals or coke, or both, during the reaction.

2. The process of Claim 1 wherein the ebullated bed is expanded from about 30 to about 50 percent during the opera-tion.

3. The process of Claim 1 wherein the catalyst in-troduced into the top of the ebullating bed contains at least about 75 percent of its total pore volume within the range of about 100.ANG. to about 300.ANG., and less than 10 percent of its total pore volume of absolute diameter within the range of 0 to about 100.ANG..

4. The process of Claim 1 wherein the catalyst in-troduced into the top of the ebullating bed contains the fol-lowing distribution of pore diameters:
0-100.ANG. <10%
200-300.ANG. >50%
400.ANG.+ <20%

5. The process of Claim 4 wherein the catalyst contains the following distribution of pore diameters:
0-100.ANG. <5%
200-300.ANG. >75%
400.ANG.+ <10%

6. The process of Claim 1 wherein the catalyst intro-duced into the top of the ebullating bed contains at least about 50 percent of the total pore volume in pore diameters ranging from about 200.ANG. to about 300.ANG., surface area ranging at least about 250 m2/g to about 450 m2/g and pore volume ranging from about 1.1 cc/g to about 1.9 cc/g.

7. The catalyst of Claim 6 wherein less than 10 percent of the total pore volume is of absolute pore diameter within the range of 0 to 100.ANG..

8. The process of Claim 1 wherein the catalyst in-troduced into the top of the ebullating bed is of particle density ranging from about 0.4 g/cc to about 0.6 g/cc.

9. The process of Claim 1 wherein the reaction is conducted at conditions characterized as follows:
Temperature, °F. (E.I.T.) 700-800 Pressure, psi 2000-5000 Hydrogen Rate, SCF/B 3000-10,000 Space Velocity, LHSV 0.5-1.5

10. The process of Claim 1 wherein the particle density of the catalyst removed from the bottom of the ebullating bed ranges from about 0.2 g/cc to about 0.6 g/cc greater than the density of the catalyst introduced into the top of the ebul-lating bed.

11. The process of Claim 10 wherein the particle density ranges from about 0.3 g/cc to about 0.5 g/cc greater than the particle density of the catalyst introduced into the top of the bed.

12. The process of Claim 1 wherein the feed intro-duced into the ebullating bed is characterized as follows:
Gravity, °API -5 to 20 Heavy Metals (Ni & V), ppm 5-1000 1050°F.+, Wt. % 10-100 Asphaltenes (C5 insoluble), Wt. % 5-50 Con Carbon, Wt. % 5-50

13. The process of Claim 12 wherein the reaction is conducted at severities sufficient to convert at least about 30 percent of the 1050°F.+ material to 1050°F.- material, while removing at least about 80% of the metals from the feed.

14. The process of Claim 1 wherein the feed intro-duced into the ebullating bed is characterized as follows:
Gravity, °API 0-14 Heavy Metals (Ni & V), ppm 200-600 1050°F.+, Wt. % 40-100 Asphaltenes (C5 insoluble), Wt. % 15-30 Con Carbon, Wt. % 10-30

15. The process of Claim 14 wherein the reaction is conducted at severities sufficient to convert at least about 30 percent of the 1050°F.+ material to 1050°F.- material, while removing at least about 80% of the metals from the feed.

16. The process of Claim 14 wherein from about 40 percent to about 60 percent of the 1050°F.+ material is con-verted to 1050°F.- material, and from about 85 to about 90 percent of the metals are removed from the feed.