CA1091605A - Combined desulfurization and conversion with alkali metals and sodium hydride - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

In an improved process for the combined desulfurization and hydroconversion of various sulfur-containing petroleum oils, the feedstock is contacted with an alkali metal or sodium hydride in a conversion zone maintained at specified conditions such that the feedstock is both desulfurized and subjected to significant hydroconversion. This is particularly demonstrated by significant reductions in the 1,050°F+ fraction of the feedstock, as well as significantly decreased Conradson carbon and increased API gravity. In addition, the deep demetallization and moderate denitrogenation of the feedstock is also achieved.
These important results are obtained by maintaining the conversion zone at temperatures of above 750°F, and in the presence of sufficient added hydrogen pressure in the conversion zone of between about 1500 and 3000 psig.

Description

-6 ~ ~

1 The present in~ention relates to a process or the

2 combined desulfurizat~on and conversion of sulfur-containing

3 hydrocarbon feedstocks in ~he presence of alkali me~als or sodium hydride and added hydrogen.
Because of the large amounts of sulfur-bearing 6 fuel oils which are currently being employed as raw mater-7 ials in the petroleum refining industry, the problems of air 8 pollution, particularly with regard to sulfur oxide emissions, 9 has become of increasing concern. For this reasonj various 0 methods for the removal of sulfur from these feedstocks have 11 been the subject of intensive research efforts by ~his in-12 dustry. At present, the most practical means of desulfur-13 izing such fuel oils is the catalytic hydrogenation o~ sul-14 fur-containing molecules at elevated pressures and temper-atures in the presence of an appropriate catalyst.
6 While these processes are relatively e~icient in 17 the case of certain distillate oils, they become less effi-18 cient as increasingly heavier feedstocks, such as whole or 19 topped crudes and residua are employedO This generally arises both from the fact that the generally high molecular 21 weight sul~ur-containing compounds therein cannot di~fuse 22 through the catalyst pores, and further the presence of 23 large amounts o asphaltenes which tend to form coke deposits 24 on the catalyst surace thereby deactivating same. Further, 2S such ~eedstocks are also contamina~ed with heavy metals 26 which also tend to deposit on the catalyst surface and de-27 activate same, Additionally, these catalytic desulfuriza-28 tion processes do not effect any significan~ conversion of the feedstocks employed.
Therefore, as alternative desulurization pro~
31 cesses, alkali metal dispersions, 8uch as sodium disper-32 sions and sodium hydride have been used as desulfuriz~tion - 2 - ~

1~9~g~0S

1 agents in the treatment of hydrocarbon oils. These pro-2 cesses, however, have also suffered from several distinct 3 disadvantages Specifically, ~hese have included relatively

4 low desulfurization efficiency, due partially to the forma-tion of substantial amounts of organo~sodium sal~s, the 6 tendency to form increased concentrations of high molecular 7 weight polymeric components, such as asphaltenes, the fail-8 ure to adequately remov~ metal contaminan~s from the oil 9 and the ~ormation of salt~oil mixtures that are exceedingly difficult to resolve so as to regenerate alkali metal there-11 from. Furthermore, these processes have never been capable 12 of achieving both significant desulfurization and the hy-13 droconversion of the feedstocks being so treated.
14 In accordance with the present invention, it has now been discovered that various sul~ur~containing hydro-16 carbon-containing feedstocks, and most significantly various 17 whole or topped crudes and resid-~ feedstocks, can be both 1a desuLurized and upgraded by means o hydroconversion by 19 contacting same in a reaction zone with a desulfurizing agent comprising an alkali metal or sodium hydride when ~he 21 contacting is carried out at certain speci~ied condi~ionsO
22 Speci~ically, such contacting is thus carried out in a con-23 version ~one which is maintained at a temperature of a~
2~ least about 750F., and in the presence of sufficient added hydrogen to produce a hydrogen pressure in said.conversion 26 zone of between about 1500 and 5000 psigo 3_.

6~5i Thus the present inVention provides a process for the desulfurization and hydroconversion o~ a sulfur-containing heavy petroleum oil feedstock containing at least.10 weight ~ o~
components boiling above 1050F, which comprises a) contacting said sulfur-containing petroleum oil feedstock with sodium hydride at elevated temperatures in the presence of hydrogen, the hydrogen providing a hydrogen partial pressure with-in the range of from about 500 to about 5000 psig., said feedstock being maintained substantially in the liquid phase, to form an oil phase having a reduced sulfur content and a reduced Conradson carbon content, and a salt phase; or b) contacting said feedstock with a metal selected from the group consisting of the alkali metals and alloys thereof, in a conversion zone, said conversion zone being maintained at a temperature above about 750F and in the presence of suffîcient added hydrogen to produce a hydrogen partial pressure of at least about 2000 psig. and wherein said alkali metal is present in said conversion zone in an amount such that the alkali metal to fced sul~ur mole ratio is maintained at between about l.0 and 3.0, whereby the sulfur content of said feedstock is reduced by at least about 50 weight %.

-3a ~' ~9 i 6 ~ 5 In one embodiment of the present invention the al-kali metal desulfurizing agent employed, which is converted to alkali metal sulfide during the aforesaid contacting, is separated from the desulfuri~ed and substantially upgraded products withdrawn rom the conversion zone, and regenerated and recycled for further use therein. Such regeneration may be accomplished in several manners, preferably by the conversion of the separated alkali metal sulfide to alkali metal polysulide, and subsequent electrolysis thereo to produce the alkali metal for recycling, or the oil-salt mix-ture removed from the conversion zone may be pretreated with water and/or hydrogen sulfide prior to such electrolysis to similarly recover and regenerate alkali metal.
In another embodiment of the present invention feedstocks comprising heavy hydrocarbon fractions may be subjected to a high degree of hydrodesulfurization as well as hydroconversion by initially contacting the feedstock with a hydrodesulfurization catalyst which is effective or the selective hydrodesulfurization of the lower-boiling oomponents of the ~eedstock. The hydrodesulfuriæation cata-lyst employed, in combination wlth the specific hydrodesul-urization conditions maintained in the conversion zone, is thus designed to avoid the conversion o the asphaltene com-.

j--J

9 ~

1 ponents of the feedstoc~s, specifically while between abo~t 2 30 and 80% of the sulfur in such feedstocks is removed 3 therein, Subsequently, the products of this catalytic hy-4. drodesulfurization step, which are now at least partially de-sulfurized, are then contacted with an alkali metal or sodi-6 um hydride in a conversion ~one, at elevated temperatures 7 and in the presence of added hydrogen, so that at least 8 about 90% o~ the sulfur originally contained in the initial 9 hydrocarbon feedstocks is now removed therefrom, and further so that at least about 50% of the 1050F+ portion of said ll feedstock is converted to lower~boiling products, In this l2 manner, the catalyst life expectancy of the hydrodesulfur-l3 i.zation catalyst is extended by a considerable degree, while l4 at the same time the hydrodesulfurization requirements of the relatively more expensive alkali metal desulfuriæation l6 a~ent is held to a minimum, whereby the higher boiling com-17 ponents, particularly the asphaltenes, are desulfurized and 18 subjected to hydroconversion therein.
l9 The selective hydrodesulfuriæation catalyst which ~ i9 thus employed in the initial step of this embodiment of the 2l present process thus comprises at least one metallic hydro~
~a ~enat~on component supported on a porous base~ specifically ~3 wherein the pore diame~er of the catalyst ranges from between 24 about lO to 100 Angstroms, pref2rably between about 20 and 2s ~0 ~n~stroms, and most pr~erably between about 30 and 50 26 Angstroms, whereby the asphaltene agglomerates, including 27 the majority of the metalmcontaining components in the ini~
28 tial hydrocarbon feedstock, do not have access to the cata-~ lyst surfaces thereofO Since these components are therefore not engaged in the catalytic desulfurization step~ the 3l problems of contaminat:ion and deactivation of the catalyst 32 surfaces with these components is overcome, while at the

5 -~l~t916(J~ii 1 same time hydrodesulfurization of the lower-boiling com-2 ponents, generally the 1050~F- components is accomplished 3 therein. In this manner, between about 60 and 80% of ~h~
4 sulfur initially contained in these feedstocks or between about 80 and 99% of the sulfur in the 1050F- components

6 of the feed, is removed in the catalytic hydrodesulfuriza-

7 tion step. The preferred catalysts comprise alumina, or

8 alumina-containing m~terials having pore diameters of be-

9 tween about lO and lO0 Angstroms, preferably between about 20 and 80 Angstroms, and a surface area of between about 11 200 and 500 square meters/gram, a8 well as a por~ volume o~
12 ~rom about 0.2 to 0.5 cc/gram, impregnated or cogelled with 13 a hydrogenation component or components. Generally, metals 14 of Groups VIB and VIII, and most preferably, combinations thereo, are preferred as the metallic hydrogenation compon-16 ents.
17 The process of this invention is generally applic-18 able to any sulfur bearing feedstock~ Thus, while the pro-19 cess is applicable to distillates, the process is p~rticu-larly ef~ective when utilized to treat heavy hydrocarbons, 21 e.g., those containing residual oils. Preerabl~, ~herefore, 22 the process of the invention is utillzed for the treatment 23 o~ whole or topped crude oils and residua. Crude oils ob-24 tained from any area o the world such as the Middle East, e.g., Saaniya, Arabian heavy, Iranian light, Gach Saran, 26 Kuwait, etc.~ the U.S. or Venezuelan, e.g Laquinillas, Tia 27 Juana, Bachaquero, etc~, as well as heavy gas oils, shale 28 oils, heavy catalytic cycle oils, tar sands or syncrudes derived from tar sands, coal oils, bitumen derived from tar ~ sands, and asphaltenes, can be treated by the process of 31 this invention. Additionally, both atmospheric residuum 32 (boiling above about 650F~) and vacuum residuum (boiling ~ 6 -il~ 9 i 6 ~ ~

1 above about 1050F ) can be treated. Preferably, the feed-2 stock is a sulfur-bearing h~avy hydrocarbon oil containing 3 at least abou~ 1 0 wt~ ~/0 sulfur, generally above about 3.0 4 wt.% sulfur, and having at least about 10% of materials boiling above 1050F., more preferably at least aboùt 40%
6 of material boiling above 1050F.
7 The feedstock may be directly introduced into a 8 contacting zone for desulfurization and hydroconversion w ith-9 out pretreatment. It is desirable, however, to desalt the feedstock in order to prevent NaCl contamination of the ll sodium salt products of the desul~urization reaction.
l2 Desalting is well known in the refining industry and may be l3 effected by the addition of small amounts of water to the 14 feedstock to dissolve the salt followed by the use of electrical coalescers~ The oil is then dehydrated by con-l6 ventional means.
l7 The alkali metals which may be employed for the l8 present process generally include the metals contained in 19 Group IA of the Periodic Table of the Elements, lncluding lithium, sodium, potassium, rubidium and cesium. Sodium, ~l however, is the most prèferred alkali metal for use herein.
~2 The alkali metal, e.g~ sodium, may be used as a 23 dispersion o~ the pure metal. Further, it i8 al80 considered 2~ tha~ 90dium or alkali m2tal alloys, e.g. sodium-lead alloys, can be used as the treA~ing agent. With re~pect to the 26 present invention, it has been discovered that at the speci-27 ~ic elevated temperature and pressure conditions disclosed -28 herein both high degrees of desulfurization and the hydro-29 conversion may be obtained, without increased coking The ~ amount of alkali me~al such as sodium employed in the con-3l version zone will depend upon the sulfur content o the feed.
32 Speci~ically, where feedstocks containing from abou~ 2 to 3 `

9 ~ 6 ~ ~

l weight percent sulfur are employed, from about 1.5 to 3 2 weight percent sodium (alkali metal) based on the to~l 3 feedstock may be employed, and where sulfur-containing eed-4 stocks including from about 4 to 5 weight percent sulfur are employed, from about 3 to 6 weight percent sodium (alkali 6 metal) based on the total feedstock present may be employed.
7 More specifically, the mole ratio of sodium (alkali metal) to 8 sulfur is preferably held in the range of from about 1 to 3, 9 more preferably from about 2.0 to 2.8. It has thus been found tha-t the use of more sodium than specified in the Above ll ranges produces an undesirable polymeric coke from the 12 residua nitrogen compounds at the conditions employed herein.
13 Sodium hydride may be charged in a granular form 14 ranging from powders (100+ microns) to particles (14 to 35 mesh range) or may be blended in a powder form with the feed-16 stock prior to charging. Powders are preferred, however, in 17 order to ma~imiæe reaction rate and minimize the need for a mechanical agitation beyond the point of initial blending 19 o powders and feedstock, The sodium hydrlde may also be employed as a dispersion in a paraffinic o~l or in a portion ~l o the product oil produced from sodium hydride treating.
~2 Furthermore, the sodlum hydride may be dispersed on a suit-able support, such as coke, charcoal and the like to provide ~4 a well dispersed supported sodium hydride. Use of sodium hydride in this form permits operating the process of the 26 invention with a fixed or fluidized bed of sodium hydride.
27 The amount of sodium hydride employed generally, 2~ may range from about 1 ~o about 15% by weigh~ of the feed-29 stock, and preferably from about 1 to about 10% by weight thereof, depending on the sulfur content of the feedstock.
3l Thus~ from about 1 to about 4 moles of sod~um hydride per 32 mole of sulur in the eedstock can be employed, and pre-~ 9 1 6 0 5 1 ferably from about 2 to about 3 and more preerably from 2 about 2 to about 2.5 moles of sodium hydride per mole of 3 feed sulfur 4 The conditions under which ~he alkali metal or sodium hydride is contacted with the particular sulfur-6 containing feedstock described above is carried out is 7 critical to obtaining the results which may be achieved by 8 employing the present invention. That is, the reaction 9 temperatures of greater than about 7S0F. J preferably greater than about 800F. and most preferably between about ll 800 and 9Q0F must be employed Furthermore, it is also 12 essential that specific elevated hydrogen pressures be em-13 ployed within the reaction zone, generally above about 1500 14 psig, preferably between about lS00 and 5000 psig, more preferably between about lS00 and 3000 psig, and most pre-l6 ferably between about 2000 and 2500 psig.
17 Contact of the sodium hydride, hydrogen and the 18 ~eedstock i9 carried out at reaction conditions designed to 19 maintaln the bulk of the feedstock, and preferably substan-tially all of the eedstock in the liquid phase.
21 As ~or the hydrogen required in this process, it 22 can be introduced into the conversion zone either as pure 23 hydrogen, as an example that from a steam reforming process, 24 or as diluted hydrogen gas streams, such as discarded re-finery stream~ produced in hydrotreating processes, e~c.
26 Contaeting in the conversion zone to efect slmul-27 taneous desulfurization and hydroc~nversion may be conducted 28 as either a batch or continuous operation, but continuous ~ operation is obviously preferableO In addi~ion, the staged treating of the feed wlth successive additions of fresh 3l reagent may be employedO
~2 The petroleum oil feedstock and the sodium or _ 9 _ 'lO~lLG(~si 1 other alkali metal or sodium hydride can be passed through 2 one or more reactors in concurrent, cross-current, or counter-3 current flow, etc. It is preferable that oxygen and water be 4 e~cluded from the reaction zone; therefore, the reac~ion s syste~ is thoroughly purged with dry nitrogen and the feed-6 9tack dried prior to introduction into the reactor. It is 7 unders~ood that trace amounts of water, i.e. less than about 8 0.5 weight percent, preferably less than abou~ O.l weight 9 percent based on total feed, can be present in the reactor.
When there are larger amounts of water, process efficiency 11 will be lowered somewhat as a consequence of the sodium or 12 other alkali metal reacting with the water. The resulting 13 oil dispersion is subsequently removed from the desulfuriza-14 tion and hydroconversion zone, and the alkali metal or sodium may then be regenerated and recovered or recycling 16 by conventional means. Initially, the oil dispersion i~
17 contacted with either water or hydrogen sulfide, prior to 18 electrolysis thereo for the regeneration of sodium or 19 sodium hydride to acilitate separation of salts from the oi~.
21 ~s described above, the process disclosed herein 22 may be employed or the combined hydrodesulfurization and ~3 hydro~onversion of heavy hydrocarbon feedstocks containing 24 ~rom between about 2 to 30% asphaltenes, particularly the asphaltene fraction of petroleum residua characterized by 26 ~ high molecular weight (generally from lO00 to lO0,000) 27 basically polycyclic aromatic structure, rich in sulfur, 28 me~als,and nitrogen.
29 It is unnecessary to subject ~he feedstocks which are to be fed to the initial cataly~ic hydrodesulfurization ,--31 step to various deasphalting processesJ as has been done in 32 the prior art. SinceJ however, various alkali metal salts

- 10 1~9~

will be produced during processing in connection with the ~ alkall metal desulfuriæing agentJ in order to prevent sodium 3 chloride contamination of these alkali metal salts therein, 4 it is preferred, as described above, to desalt the feedl 5 preferably prior to the original catalytic hydrodesulfuriza-6 tion step.
7 As stated, the selective hydrodesulfurizing cata-8 lysts employed in this step include an alumina-containing 9 porous base which is impregnated or cogelled with a hydro-genation component. Specifically, the alumina-containing

11 porous base comprises alumina, or alumina in combination

12 with a metal from Groups III, IV or V of the Periodic Table,

13 such as boron, silicon, phosphorous, etc. Specifically,

14 combin&tions of silica and alumina, alumina and aluminu~
phosphate, alumina and boria, etc., are most preferred.
16 These porous bases are thus prepared by gelling or cogelling 17 the base materials according to well known procedures. It 18 i8 most essential, however, that ~he particular porous base 19 employed thus have pore diameters of between about lO and lO0 Angstroms, preferably between about 20 and 80 Angstroms, 21 and most preferably between about 30 and 50 An~s~roms, a 2~ surac~ area of from about 200 to 500 square me~ers/gram, ~3 and a pore volume of above about 0.2 cubic centimeters/gram, 24 preerably from about 0.2 ~o 0.5 cubic centimeters/gram.
These characteristics, and particularly the average pore 26 diameter employed, thus assure that the higher boiling or 27 asphaltene-containing agglomera~es contained in the particu--28 lar hydrocarbon feedstock employed will not have access to ~ the active catalytic surfacès contained in these catalysts.
These surfaces are thus prepared by impregnating or cogelling 31 p~rticular metallic hydrogenation components with these 32 porous bases. Specifically, metallic hydrogenation compo-nents from Groups VIB and VII~ ~f -the perioaic Table of the Elements, includi~ng chromium, moly~denum and tungsten~ f~om Group VIB, and n~ckel and co~`alt, from Group VIII are preferred, and most preferably combinations of one such metal from Group VIB and one suc~ metal from Group VIII`. Generally, catalytic metals are incorporated at the time the base materials are gell-ed or cogelled, and catalyst pore size is regulated by the gellation media, e.g. r ~ater or water-alcohol mixtures, hydro-gen ion concentration and drying procedure.
The conditions in the initial catalytic hydrode-sulfurization step are thus also sel'ected in order to prevent the dissociation or conversion of the asphaltene agglomerates, including most of the metallic-containing materials in the feed stock. Specifically, preferably temperatures o~ between about 550 and 800F., more prefera~ly-between about 700 and 750F., are employed, in addition to pressures of preferably from about 200 to 2000 psig, more preferably from about 1200 to 1800 psig, and most preferably from about 800 to 1500 psig and flow rates of preferably from about 0.2 to 5 V/V/Hr, more preEerably from about 0.5 to 1.0 V/V/Hr. It is therefore possible to at le~st partially desulfurize the asphaltene-containing feedstock r mostly by desulfurizlng the lower-boiling components the~eof r so that preferably no more than about 70% desulfurization of the Eeedstockr more preferably only about G0% and most prefer-ably only from about S0 to 6~ desulurization is obtained therein. Again r this pro~ides for little if any involvement of the asphaltenes in this catalytic desulfuriæation step. The hydrogen consumption in the'catalytîc hydrodesulfurization step is thus maintained at relativeIy lo~ flgures of preferably from about 250 to 800 SCF/B, more'generally from about 40U to 6ao SCF/B, and the catalyst life'expectancy of such catalysts is maintained ~: .

10 ~ ~ 6 ~ ~

1 at hi~h levels, surh as those observed for the hydrodesul~
2 furization of lighter feeds, such as vacuum gas oils, etc.
3 Generally, catalyst life of abou~ one year is realized 4 before regeneration is required. Regeneration of these s catalysts may then be accomplished by procedures well known 6 in the art.
7 By operating in the manner described above, the 8 desulfurization which occurs in the catalytic desulfuriza-9 tion step thus results in the generation of hydrogen sulfide therein. Of necessity essentially all o the hydrogen sul-11 fide is removed from the product obtained in the catalytic 12 de~ulfurization step prior to additional desulfurization by 13 contacting with the alkali metal desulfurizing agent. This 14 i9 generally accomplished by purging the liquid stream of hydrogen sulfide by hydrogen stripping or flashing ligh~er 6 products from the partially desulfurized liquid. The hydro-7 gen sulfide thus removed may be employed subsequen~ to the 18 contact with the alkali metal desulfuriæing agent in the 19 manner described above.
As is disclosed hereinabove, contacting of the 21 alkali metal or sodium hydride and sulfur-asphaltene con-22 taining ~eedstock is carried QUt at eleva~ed ~emperatures ~3 and ln the presence o~ added hydrogen in order that combined 24 hydrodesulfuri~,ation and hydroconversion of the heavier feed 2s components is obtained. In this manner, the bulk of the 26 reactants within the reaction zone are maintained in a 27 liquid phase, and the alkali metal is in a molten state.
28 The alkali metall such as sodium, reacts with the sulur-29 containing oil in a manner to yield sodium sulfide, which ~ generally forms as a micro-crystalline dispersion in the oil.
31 This is accomplished as follows:
32 2Na ~ S-oil ~ Na~S ~ oî.l : --f - ~9~s 1 Additionally, the metals and nitrogen content of 2 the feedstock is reduced by reaction with sodium, and the 3 higher boiling, or 1050F.~ portion of the feedstock is both 4 hydrodesulfurized and converted to lower-boiling products.
Because of the prior removal of sulfur from the lower boiling 6 components thereof, the relatively more expensive alkali 7 metal employedl e.g., sodium, concentrates on the desuliuri-8 zation of ~hese asphaltene compounds, and a highly economi-9 cal process evolves.
The oil dispersion which is thus removed from the ll combined hydrodesulfurization and hydroconversion step in 12 the presence of the alkali metal or sodium hydride hydrode-13 sulfurizing agent, thus containing alkali metal salts, pre-14 dominantly alkali metal sulfide, thereinJ is then contacted with hydrogen sulide in amounts ranging preferably from about 16 lO0 to 400 mole percent, more preferably 110 to 200 mo].e per-17 cent, based upon the total number of moles of salt present in 18 the mixture. The net consequence oE such H2S treatment is 19 twoEold: (l) At least a portion of the by-product alkali metal salts, Eor example, such sodium salts as sodium oxide, 21 sodium hydroxide and the like are converted to sodium hy-22 drosulfide, and (2) Submicron salts are agglomerated to 23 yield a macrocrystalline salt phase (preferably having a 24 particle size between about 150 to 200 microns) which readily disengages from the oil phase. The salt phase is 26 separated from the oil phase and recovered employing one of 27 several well-known commercial techniques, notably filtra-28 tion or centrifugation. The H2~-treated mixture of salts 29 is then treated in various known ways in order to regenerate alkali metal therefrom.
31 Figure 1 is a schematic flow diagram of the com-32 bined desulfurization ~nd hydroconversion process according ~ 14 ~

~9~s l to the pr~sent invention, including regeneration.
2 Referring to Figure 1, a sulfur-containing feed-3 stock, preheated to 450-500F., is fed by means of line 1 4 and pump 2 to separator vessel 3 where trace amounts of water and light hydrocarbon fractions are removed through 6 line 4. The feed is then discharged through line 5 by pump 7 6 to filter ~essel 7 wherein particulate matter, i.e., coke, 8 scale, etc. is removed.
9 The feed is preliminarily desalted by conventional means (not shown). Feed exiting the filter via line 8 is ll split into two streams. A small portion is fed through line l~ 9 ~nd heat exchanger 14 to dispersator vessel 11 where a l3 dispersion is formed with sodium enterlng through line 67.
l4 The dispersator vessel is of a conventional dèsig~ and is opera~ed at 250-300F. at atmospheric pressure. The vessel 16 is blanketed with hydrogen. The resultant dispersion, drawn 17 ~hrough line 12, blends with ~he balance of ~he feed in 18 line lO and enters the charglng pump 13, where the pressure 19 i9 raised to about 2000 psig.
The oil enters heat e~changer 16 v~a line 15 where 2l ~he temperature is raised ~o about 750F. to 800~F. and i8 22 then ~d through line 17 to reactor vessel 18. The reactor 23 contains ba~les 19 ~o promote continui.ng contact between 24 sodium and the oil and to prevent by-passing from the inlet ~5 to the outlet. Hyd-~ogen is introduced into the reactor 26 vessel 18 via llne 74 in amounts such that the total partial 27 pressure of hydrogen in the reaetor ranges between about 28 1800 and 2000 psig. Holding time in the reactor is about ~ 15 to 120 minutes and i8 preerably abou~ 60 minutes. The temperature at the top of reactor 18 is about 870. Gas 3l that is formed due to the increase in temper~ture and excess 32 hydrogen is taken overhead througb line 20 and is condensed ~ 60 5 1 and depressurized by conventionalImeans ~not shown). The 2 desulfurized oil containing dispersed sodium sulfide and 3 other salts leaves the ~op of reactor 18 via line 21.
4 Sodium sulfide-oil dispersion, previously depres-sured to about 200 psig in a stripping tower (not shown) 6 is lntroduced via line 21 into contacting vessel 22 wherein 7 the dispersion is contacted with about 30 to 80 mole percent 8 hydrogen sulfide based on the total moles of salts oontained q in the oil, at a temperature between about 600F. and 800F.
1~ preferably be~ween about 700F. and 780F. The pressure is 11 maintained between about 200 and 400 psig. Hydrogen sulfide 12 is introduced into said contactor via line 23. Residence l3 time in the contactor vessel is on the order of about 10 14 minutes, although longer or shorter times may be used if desired.
16 The H2S-treated dispersion exits through line 24 17 at about 720F. and from 200 to 300 psig, and is then cooled 18 to about 450F. in heat exchanger 25. The mixture is then 19 fed through line 26 to hydroclone vessels 27 and 28 in ~ series to disengage the oil-salt mixture. Alternatively, 21 by maintaining the H2S-treated mixture above about 700F.
22 it is possible to disengage from the oil a molten layer of 23 sodium hydrosulfide in a liquid-liquid separator (not shown).
24 Desulurized oil is then withdrawn via line 29 to heat ex~
changer 30 and exits at from 250F. to 300F. ~hrough line 26 31. An acid, such as dilute sulfuric acid or acetic acid, 27 may be injected into line 31 through line 32 to react with 28 oil-soluble sodium salts, e.gO D sodium`mercaptides and the 29 like, and the resultant mixture enters the electrostatic ~ precipitator 34 via line 33O The acidic aqueDus phase from 31 vessel 34 is withdrawn through line 36 and disearded. De-32 sulfurized oil is fed through lin- 35 to steam~t~ipper 37 ; 16 --~9~s 1 and subsequently to storage via line 38.
2 Oil-salt slurry withdrawn from the hydroclone 3 ves~els through lines 39 and 40 is fed to wash ves~el 41 4 where a light hydrocarbon wash, entering through line 42, is used to remove heavy adhering oil. The wash effluent i8 6 drawn off through line 43 and is eventually fractionated to 7 recover the desulfurized oil content and the light hydro-8 carbon. The wash vessel operates a~ from about 50 to 200 9 p8ig and at temperatures of from about 200F. to 250F.
0 A slurry of washed solids is fed through line 44 to drier 11 45 to remove light hydrocarbons whioh are taken of~ through 12 line 46.
13 Dry solids are fed to blending vessel 48 via line 14 47~ wherein contact is made with sulfur-rich polysulfide Na2Sx, where x ranges from about 4~4 to 4.8, which enters 16 the blending vessel 48 through line 49. The contacting is 17 conducted at a temperature o~ ~rom about 600F. to 700~F~
18 preferably from about 600F. to 650F.~ and at a pressure 19 between about atmospheric pressure and 100 psig, pre~erably be~ween atmospheric pressure and 50 psig~ Hydrogen sulPide 21 released in the blending reaction along with some small 22 amount of light hydrocarbon is removed through line 50, 23 blended with makeup hydrogen sul~ide entering from line 51 24 and is recycled to vessel 22 by way of line 23.
2s The molten sulfur depleted polysulfide ~Na2Sy, 26 where y ranges from about 3.5 to 4.2) is removed from 27 blending vessel 48 thrcugh line'52 and fed to ~ilter vessel~
28 53 to remove particulate matter such as coke and melt in-soluble salts. Line 54 i~ used to purge a small stream of sodium polysulfide from the system in order to prevent 31 buildup of impurities to an inoperable level, 32 These dissolved impurit~es arise from the feed and ~ 9 ~6 0 S

1 from equipment corrosion as well as from the organo-metallic 2 compositions removed from the feed by the action of sodium.
3 Specifically, compounds containing combined lron, vanadium, 4 silica~ nickel, chromium, lead and tin may form and are removed from the system via line 540 6 The filtered, purged sulfur-depleted sodium poly-7 sul~ide, Na2Sy, is introduced into cell 56 via line 55.
8 A dry nitrogen stream ~not shown) blanke~s the 9 electrolytic cells. The electrolytic cells are of a con-ventional design and may comprise any cell capable o 11 converting the polysulfide to sodium metal. Preferably, 12 the individual cell unit comprises a molten sodium-contain-13 ing cavity and a molten ~odium polysulfide-containing 14 cavi~y separated from each other by a sodium ion-permeable membrane comprIsing preferably crystalline beta-alumina.
16 Finally, the sodium polysulfide, Na2Sz where z ranges from 17 about 4.8 to 5.2, which is formed in the electrolytic cell 18 56 is passed via line 5~ to surge vessel 58 and then to 19 sul~ur-reducing vessel 60 which is partialLy evacuated e.g. to an absolute pressure of from about 10 to about ~1 300 mm Hg, preerably from about 50 to about 100 mm Hg, to 22 v~poriæe some of the sulfur and reduce the sulfur con~ent 23 o~ the polysul~ide 80 that the ~inal polysulfide composition 24 is Na2Sx where x takes values ranging from about 4.0 to about 4.9, preferably from about 4.4 to about 4.8.
26 At one-tenth atmosphere sulfur vapor pressure, 27 for ex~mple, the composition in equilibrium therewith is ?8 approximatelY Na2S4 82 at 700 F., Na2S4.73 at 750 F-~ Na2S4,64 at 800~F. The sulfur vapor is taken overhead through lin~ 61 and condensed by conventional means (not 31 shown). As indicated previously the resulting polysulfide 32 i9 then recycled via line 49 to scrubbing tower 48.

.

Alternatively, at least a portion of the sodium polysulfide 2 stream exiting from the cell can be contacted directly wi~h 3 the H2S-treated salt mixture, thereby by-passing the 4 evacuating operatlon in vessel 60 Thus, ~or exa~ple Na2Sy exiting from the cell can be contacted directly with the 6 H2S-treated salt mixture. The molten sodium is subsequently 7 removed from the electrolytic cell and passed via line 62 8 to surge vessel 63 where it is blended with makeup sodium 9 entering at line 64 and then ed via line 65, pump 66 and line 67 to vessel ll.
11 The present process may be further understood by 12 reference to the following examples thereof.

4 The combined desulfurization, hydroconversion, demetallization, and denitrogenation of a Safaniya atmos-16 pheric residuu~ feedstock as shown in Table I was carried 17 out employing sodium metal. The results obtained, and the 18 process conditions employed, are contained in Table II
19 hereOf-These res~lt~ clearl~ demonstrate the e~fective-21 ness o~ the sodium employed no~ only for deep d~sul~uriza-22 tion of the sul~ur-contai~ing eedstock employed, but also ~3 ~or the hydroconversion, partial denitrogenation, and 24 demetallization thereo~. Thus, approximately 98Z of the sulfur content o~ the feedstock was removed therefrom~
26 while at the same time Conradson carbon losses of almost 27 70% were obtained9 along with almost quantitative me~als ~8 removal. Additionally, API gravity increase3 from 14.4 to 27 and 28.l were achie~ed. Finally, about 75% of the 1,050F.~ fraction of the feedstock employed was converted 31 to lower bolling products.
32 E _ 9~16~)5 1 In order to compare the improved resu~ts ~or 2 desulfurization, hydroconversion, partial denitrogenation 3 ~nd demetalllzation shown in E~mple 1 with similar pro-4 cesses carried out outside the ranges o~ pre~erred condi-tion6 forming the essence of the present invention, sev~ral 6 additional runs were carried out employing the same Safaniya 7 atmospheric residuum feedstock described in Table I. These 8 results, and the process condi~ions employed in each, are 9 contained in Table III hereof.
Run~#3 shown in Table III represents a typical 11 desul~urization run carried out according to the prior art, 12 such as ~or example U.S. Patent No. 3,787,31S. This desul-13 furizatlon run, carried out at a moderate temperature o~
14 650F., and under a low hydrogen pressure of 200 psig, doeR
result in the excellent desulfurization of a residua eed-16 stock, with some concurre~t hydrogen up-take. Re~ction 17 time8 of ~rom 0.5 to 2.0 hours have been tested, and it ha~
18 been shown that l~ttle if any change occurs a~ter a l.0 19 hour contact ln the temperature ranges shown in the a~ore-mentioned patent, namely, fromsabout 600 to 730F~ In view 21 ~P the amount o hydrogen so consumed, which i~ ~enerally 22 found to be roughly one mole per mole of sulfur removed ~3 from the oil, there is a strong indication that the hydro-24 genation reaction and desulfurization reaction are related accordlng to the ~ollowing equation:
26 RSR ~ 2Na --~ 2R- + Na2S
27 2R- ~ H2 ~ 2RH
28 where R a h~drocarbon radical.
29 Thu89 any con~ersion which occurs during this reaction merely derives from the ~ragmentation of sulfur-31 bearing molecules, with the hydrogen acting to heal the 32 organic rad~cals so produced. For this reason any conver-~09~L60 1 sion which occurs is relatively constant ~or most 650F.
2 residua feeds, generally averaging about 15 ~o 20% reduc-3 tion in a given feeds~ 1,050F.~ bottoms fractlon. The 4 amount of hydrogen thus consumed amounts to approximately 12 SCF per pound of sul~ur removed or abou~ 120 to 150 SCF/B
6 when Sa~anlya type feeds are processed to approximately 7 0.3% sul~ur content products D
8 As shown in Run ~49 under a higher hydrogen pres-9 sure o~ 1200 psig, and temperatures in the 700 to 730F.
lo range, very little additionsl conversion of 1,050F.~
11 bottoms is observed, although additional hydrogen up-take l2 is demonstrated. Run~ #5 and #6 were carried out at higher 13 temperatures, namely those within the range of the present 4 invention, while hydrogen pressures o~ 1750 psig, i.e. on the low end ~f the ran~e required by the present inventi~n, 16 were employed. Extensive cracking was obtained, in large l7 part derived ~rom hydrocracking. Thus, the l,OS0F.~
18 fraction of the feed wa~ reduced by about 80Z, and there 19 wa~ extensive overall convexsion of the ~eed. Hydrogen con~umption ~n these ~uns was higher than that obtained 21 undér the hydro~lning conditions employed in Run ~4, but 22 the amo~nt o~ hydrogen was 8till not su~icient to impart ~3 8tability to the cracked liquid product, it wa8 thus found 24 that these liquid products developed sludge ater standing 2s for several days, as was the case in Run ~7. Such sludg~ng 26 causes serlous process problems in terms of line-pluggi~g, 27 fouling of pro~ess control devices, fauling of heat ex~ -28 changer, etc.
~ All!/o~ these Runs may thus be compared with Runs ~1 and ~2 in Example 1, wherein none of the~e deficiencies~
3l and the extremely significant desul~urization~ hydrocon~
32 version and demetalliza~ion were achieved.

~O 9 ~

1 Fur.thermore, referring to Runs ~8 and #9, the 2 sodium to sulfur mole ratio concentration was varied be-3 tween about 1.O and 2.6. The resul~s indicate that at 4 above about a ratio o~ 2.6 polymeric coke products are S formed, and that below about a ratio of l.~ producing less 6 than about 60% desulfurization, hydrocracked products form-7 ing large amoun~s of sludge are obtained.

9 To further demonstrate the scope of the present invention, particularly with respect to very refractory 1 hydrocarbon feedstocks, the process o~ the present invention 12 was carried out upon various vacuum residua and bitumen 13 feedstocks as shown in Table IV. Aæain it is evident tha~
14 by employing the prefçrred conditions o~ temperature, hydro-gen pressure and sodium concentra~ion it i possible to 16 achieve excellent desulfuriza~ion, demetallization and con-17 version of heavy components (as indicated by reduced Con-18 radson Carbon content and 1,050F.-~ boiling material~
19 without substantial loss of feed to coke or light ~C
gases.

~ 9 ~6 3RE~IDUUM EMPLOYED IN EXAMPL~ 1 4 API Gravity 14.4 Sulfur, Wt. % 3.91 6 Nitrogen, Wt. % 0.26 7 Carbon, Wt. % 84.42 8 Hydrogen, Wt. % 11.14 9 Oxygen, Wt. % 0.27 10 : Conradson Carbon, Wt. % 11.8 11 Ash, Wt. % ~-12 Water, Karl Fisher, Wt. % --13 Metsls, ppm 14 Ni 20 16 Fe 4 17 Viscosity 18 VSF 122F. 235 19 140F. 131 210F. --21 Pour Point, F 33 22 Naphtha InsolubLes, Wt. % 7 23 Distillation 24 IBP, F 464 ~S 5% ` 569 26 10% 632 27 20% 724 28 30% 806 2~ 40% 883 50% . 962 31 60% 1037 32 70%
33 80%
34 90%
95%

37 % Rec. (Wt. % 1050-) 59.2 38 % Res. twt % 1050+) 40.8 ~09~L6~

3SAFANIYA ATM~SPHERIC RESIDUA WITH SODIUM

4 Run #1 _ Run ~2 Reactor Conditions 6 Time, minutes50 30 7 Temp.~ F 826 830 8 H2 Pressure, psig 1960 1960 Na/S Atom Ratio 2 . 2 2 . 2 H2 used, SCF/B~ 760 ~ 650 11 Products, Wt. %
12 Cs~Gas 2.2 1.3 13 Coke 2.0 2.2 14 Liquid ,~91.5 92 .2 Liquid Inspections 16 Sulfur, Wt. %0.2 0.2 17 Nitrogen, Wt. % 0.2 --18 Conradson Carbon, Wt.% 3.7 --19 Ni/V/Fe, ppm< 1, all 2/1/1 API Gravity28.1 27 21 Vol. % 1,050F~90 --22 Storage Behavior 23 Pepper SludgeNone None 24 PrecipitateNone None (1-5 vol. %) ~09160S

u~oo~u~ 1_1~ o~
~C~10 ~ ... ... ~ . ~ ~
~ oo~ o~ oo_I~l~D ~ ~ I
P; ~ oo~ , C~

o~
* U~
o~oc~l~CO~O ~~
u~ I I O ~ ca co ,~
q~U~U~O~O ,`~ ~1`0~ . ~
o o . . . . . . ~q .,, ~ ~U~ ~ OOl~u~
a: ~ 0 OH
~ ~D
Zo u~ ~ 00000 ~ ~ 00 u~
H ~ u~
v~ ~:~oo 1~ c~ OO I ~ ~ 00 0 a) o ~ H P4 _I 0~ ~ c~l ~ ~ ~Z;
~2 0~
H ~ ~3 *
~3 000~0 oo~ ~ o 1~ ~:
~cl :~ oo r~ ~ ~ o oo~ o cs~ J o ~ ~ P; -' ~ 2~ ~æ
E~ Z~
u~
~ ~ ~ O O O ~ 1 0 ~
~00 0 ~ O
; ~ I~ c~l ~ ~ z ~1 o o u~ ~ ~1 00 0 0 ~ ~ ,~ D ZZ
u~
u~
0 0 ~ o ~~ I o cr~
c,~ ~ o ~, ~
z; o o o u~ zO z;

~ o~ ~q ~ ~ o ~ ~ ~ ~

~1 ~-~1 ~ ~ .,, O o u~ ~ ~i?~ ~ ~ o ~
~rl a~ ~ J ~ 00 J ~ a~. 3 c. ~,o td ~ ~ .
~ ~ C~ ~ ~ ~ ~ s ~ ~1 o d 1:4 ~ R u~ ~ ~ ~ d O
c~ .~1 0 cq o ^ ~ ~ ~ ^ ~ ~ cn q ul ~1^ a~ .,~
s~
O ~ . t) C r~ ~~ O ~~ b4 a~
~1 ~ p ~ ~ rl . ~ h ~ d Cl. c~
t) R R ~ I ~ v' 1 r~ H _I ~1 ~ ~ _~
la ~ ` C~Jo~ o ~1 v ~ o ~o o a~ 1 1 E~ l ~ l cn Z c.~ 'd P ~ P~
P~ ,_1 U~

~019~6~

o ~ . .
' O OU~Jo oo ~ .,, _ $~ FCIO O u~
O c~ l 1~ 0 o~
O ~~ 0 ~ o o~

,~ p ~ ~o o ~ oU~
o ooo ~? ~D ~ O U~ O o o~
~1~ _11~ ~ ~D~OO I

o CJ~ a~
U~ ~ ~o~, E~ ~
I
Z
o ,_~ . t~
? u~ p~
rl P; , O p h ~ ' 00 ~ O I ~ ~ 000`- ~
~C I~ ~O c~l O 00 0 cr~ o ~ 1 E-l O ~ ~oo o ~ O
P~ ::~ ~ Ln ~ Ln O ~ n o~
a ~ ~ ~ cr 0~ ,~

~ 'd O
'O ~ ~U C~ll~ ~ ~
a~ ~ ~n~ no _ C~
o ~ .~
J O O
:~ ~ s~
td . ~î
Z
,tlO-~ 3 ~ ^ Q ^~ ?~
t:~ tq O O J~ V
O ~-r~ a3 .~ 3 3 o a~
,1 ~ ~-- ~ ~ ~ ~
~ v ~ . ~ t~
~1 n O ~ J.l ~1 N O N ~ O
3 ~ .~ ~ .a ~
O ,,0 0,~ ~ O ~ a ~ ~ ~3 a~
~ ~ X ~ ~ ~d ~ o ~ ~1 1_1 C-~ 0 5~ L~ ~;
~-I ~ 1 C~ l ~) J~ ~I C.!) I td b~l~l ~ ~lo o ~ ~ c~ æ rd o~ 0 3 E~l ~ I I O t~ ~ ~ J.l t--I L~ C~ ~ 3 Lt~
;~ ~ Ll'~ L~ O IV ~ ^ O a~ O U~
E~ $ Z :C h ~ C) ~ V S~ v~ C~ X ~ ¢

~ ~ ~ Ln ~n r~ oo cr~ o r~ ~) `;t Ln ~o 1~ oo a~ o ~I c~l ~) ~ L/~

91~5 1 Examp~es 4-9 2 The inspection of the feedstock used in Examples 3 4-9 was as follows:

FEEDSTOCK_INSPECTION
6 Feed Designation Safani~a 7 1050-, Vol. % 59 8 API Gravity 14.4 9 Sulfur, Wt. % 4.0 Nitrogen, Wt. % 0.26 11 Carbon, Wt. % 84.42 12 Hydrogen, Wt. ~/O 11.14 13 Oxygen, Wt. % 0.~8 14 Conradson Carbon, Wt. % 12.1 Asphaltene, Wt. % 13.0 16 Metals, ppm 17 Ni 20 19 Fe 4 Viscosity 23 Pour Point, F 33 24 Naphtha Insolubles, Wt. % 7 R.Io 67C
26 Flash Point, F 318 27 Sodium hydride-treated oil produccs were analyzed ~8 no~ only for sulur content, but also for chan~es in metal 29 con~ent and general physical properties such as API gravity, 30 and Conradson carbon.
31 The data shown below in Table VI demonstrate the 32 effect of hydrogen pressure on desulfurization and hydro-33 conversion of the above feed with sodium hydride.

~ .6 ~ 5 TABLE VI

3AND OPERATIN~ T~MPERATURE
4batch tests - treatment of Safaniya Atmos-5pheric Residuum Feed 6 EXAMPLE NO.CONTROL A 4 5 6 7 Residuum, g 99.2 99.7 91.6 103 8 Sodium hydride, 6 6 6 6.6 9 Wt. % feed 10 Hydrogen psig 0 500 600 1500 11 Temp. F 700 700 700 820 12 Run Time, hr. 1 2 13 Residuum Product 14 Analys i8

15 Sulfur, Wt. %1.1 1~0 1.0 0.2

16 Metals

17 Ni/V/Fe (ppm)13/29/0 5/9/17llO/1 2/5/3

18 Coke, Wt. % 0.4 0 0.2 0.3

19 Conradson Car-

20 bon, Wt. % 9.2 7.4 6.3 5.0

21 API Gravity 19.2 19.8 20.8 27.2

22 Desulfurization % 70 75 75 89.6

23 Demetallization % 62 86 84 89 . 4

24 Conradson Car-

25 bon Removal % 23.7 38.8 47.5 60.0

26 1050-, Vol. % -- 65 -- 92

27 It is seen from the data of Table VI that where 23 increased hydrogen pressures and operating temperatures 29 are employed, the hydroconversion activity increaqes as reflected by the greatly ~ncreased API gravity and the 31 degree of 1050^ dis~illate of the products of Example 6 as 32 opposed to ~he products of Examples 4 and 5 and tha~ of 33 Control A.

34 Example 7 The data shown below in Table VII demonst~ate 36 the effec~ of reaction time on desulfurization and hydro-37 conversion.

- 28 -~og~6~s 2THE EFFECT OF REACTION TIME (BATCH TESTS AT 700F -3TREATMENT WITH SAFANIYA ATMOSPH~RIC RESIDUUM
4WITH SODIUM HYDRIDE AND 500 PSIG HYDROGEN) 5 EXAMPLE NO. 7 8 6 Reactants 7 Residuum g. 97.1 99.7 8 Sodium hydride Wt. % feed 6 6 9 Hydrogen, psig 500 500 lQ Reaction period, hr. 0.5 ll Residuum Product Ansl~is 12 Sulfur Wt. % 1.1 1.0 13 Metals Ni/V/Fe (ppm) 7/10/1 5/9l1 14 Coke Wt. % o o 15 Conradson Carbon, Wt. % 7.2 7.4 16 Desulfurization, % 73 75 17 Demetallization, % 84 86 18 Conradson Carbon Removal, % 40 38.8 19 API Gravity 19.9 1~.8 As seen in Table VII, Example~ 7 and 8 demonstrate 21 that the sodium hydride process of the invention is not par-22 ticularly sensitive to reac~ion period, and a holding time 23 or space velocity suited to the conversion level desired 24 may be selected.
Example 9 26 The data set out in Table VIII ~elow demonstrate 27 ~he effect of carrying out the process of the invention in 28 a sta~ed manner by successive treatments of ~he feed with

29 ~resh charges o~ sodium hydride and hydrogen.
TABLE VIII

32 _ ATMOSPHERIC RESIDUUM IN A STAGED MANNER
33 Reactants Sta~e 1 34 Residuum, g. 128.5 88.3 35 Reagent, g., Wt. % NaH 7.8,6.1 NaH 7.8,6.1 36 Hydrogen, psig, Initial 500 500 37 Reaction Conditions 38 Time, hr.
39 Temp., F. 700 700 1~ 91 6 ~ 5 1 Product Inspec~ions 2 Sulfur, Wt. % 1.05 0.67 3 Nitrogen, Wt. % -- 0.24 4 Conradson Carbon, Wt. % -- 7.3 5 Ni-V/Fe, ppm -- 5/l/2 6 API Gravity 20.0 22.4 7 Desulfurization, % 73.0 36.1 (overall de-8 sulfurization 83.0V/o) 9 Conradson Carbon Loss % -- 39.7 10 Demetallization, % -- 93.0 11 Products Recovered 12 Liquid, Wt. % on feed 96.7 97.2 13 Coke, Wt. % on feed 0 0 14 Cs-Gas, Wt. % on feed 0.2 0.2 The data in Table VIII demonstrate that desulfuri-16 zation can be increased by successive treatment of the feed 17 with fresh charges of sodium hydride and hydrogen. This 18 will be seen in comparing desulfurization of 75% in Stage 1 19 with the overall desulfurization of 83.0% in Stage 2.
Example 10 21 A Safaniya atmospheric residuum feedstock having ~2 the composition shown in Table IX9 including an asphaltene 23 content of 11.5% was sub~ected to the combined desulfuri2a-24 tion and conversion of the present invention. Initially, 25 tXi8 feed was contacted with a hydrodesul~urization catalyst 26 comprising 3.5% cobalt and 12.0% molybdenum oxides cogelled 27 with a porous base comprising aluminum phospha~e and alumlna, 28 and having an average pore diameter of about 50 Angstroms.
29 This step was conducted at the conditions, and with the re-sults, shown in Column A of Table X. Subsequently, after 31 purging of H2S, the products from this step were contacted 32 with 2.8% sodium on feed in a conversion zone maintained at 33 the conditions, and with the results, shown in Column B of 34 Table X.

These results clearly demonstrate the significant

- 30 -~ 9 ~ 6 ~ S
.

1 result9 obtainable by employing the present process, includ-2 ing an overall reduction o~ the 1050F~ portion of ~he feed-3 stock of 80%, almost quantitative demetallization, an over-4 all sulfur reduction of almost 99%, and significant nitrogen and asphaltene removal.

7FEEDSTOCK INSPECTION OF SAFANI~A
8ATMOSPHERIC RESIDUUM EMPLOYED IN ~XAMPL~ 10 9 API Gravity 14.5 Sulfur 4.0 11 Nitrogen, Wt. /O 0.3 12 Conradso~ Carbon~ W~. % 12.0 13 Asphaltenes 11.5 14 ClH Wt. Ratio 7.7 Metals 9 ppm 16 Ni 22 18 Fe 4 19 Vol. % 1050F- 59 20. Vol. % 1050F+ 41 21 Distillation 22 IBP, F. 464 23 5% 569 24 10% 632 20~/o 724 26 30% 806 27 40% 883 28 50% 962.
29 60% 1035 70% __

31 80% --

32 90% __

33 9S% __

34 FBP `1035 % Rec. 59.2 36 % Res. 40.8 Column AColumn B
41 Condi~ions 42 Temperature, F 700 825 43 Pressure, psig 1500 1750 44 H2 rate, SCF/hr. 4000 4000 45 Feed Rate, V/V/hr. 1.0 __ 46 Contact Time, hrs. -- 1.0 ~ 9~ 6 ~ S

1 Sodium Rate, lbs/B -- 10 2 (H2 Consumed, SCF/B) 330 380 3 Product~ Wt. ~/O
4 C5-Gas ~ 2% 3.7 5 Coke nil 1.8 6 Liquid 98 92.4*
7 Liquid Inspections 8 Sulfur, Wt. % 1.8 0.1 9 Conradson Carbon, Wto % 8.4 3.0 Nitrogen, Wt. % 0.2 0.1 11 Asphaltenes, Wt. % 11.1 --12 Ni/V/Fe, ppm 23/79/2 1 ppm, all 13 API Gravity 21.8 31.5 14 C/ H Wt. Ratio 7.25 7.0 15 . Vol. % 1050F- 65 (est.) 92 16 Vol. % 1050F~ 35 (est.) 8 17 * 100 vol. % on feed overall ~ 32 ~

Claims (36)

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

1. A process for the desulfurization and hydroconversion of a sulfur-containing heavy petroleum oil feedstock containing at least 10 weight %
of components boiling above 1050°F, which comprises a) contacting said sulfur-containing petroleum oil feedstock with sodium hydride at elevated temperatures in the presence of hydrogen, the hydrogen providing a hydrogen partial pressure within the range of from about 500 to about 5000 psig, said feedstock being maintained substantially in the liquid phase, to form an oil phase having a reduced sulfur content and a reduced Conradson carbon content, and a salt phase; or b) contacting said feedstock with a metal selected from the group consisting of the alkali metals and alloys thereof, in a conversion zone, said conversion zone being maintained at a temperature above about 750°F
and in the presence of sufficient added hydrogen to produce a hydrogen partial pressure of at least about 2000 psig. and wherein said alkali metal is present in said conversion zone in an amount such that the alkali metal to feed sulfur mole ratio is maintained at between about 1.0 and 3,0, whereby the sulfur content of said feedstock is reduced by at least about 50 weight %.

2. A process for the combined desulfurization and hydroconversion of a heavy, sulfur-containing hydrocarbon feedstock at least 10 weight % of which boils above about 1050°F, which comprises contacting said feedstock with a metal selected from the group consisting of the alkali metals and alloys thereof, in a conversion zone, said conversion zone being maintained at a temperature above about 750°F and in the presence of sufficient added.
hydrogen to produce a hydrogen partial pressure of at least about 2000 psig.
and wherein said alkali metal is present in said conversion zone in an amount such that the alkali metal to feed sulfur mole ratio is maintained at between about 1.0 and 3.0, whereby the sulfur content of said feedstock is reduced by at least about 50 weight %.

3. The process of claim 2 wherein the temperature in said conversion zone is between about 800° and 850°F.

4. The process of claim 2 wherein the hydrogen pressure maintained at said conversion zone is between about 2000 and 2500 psig.

5. The process of claim 2 wherein at least about 50 weight percent of said 1050°F + materials are converted to lower boiling materials in said conversion zone.

6. The process of claim 2 wherein said alkali metal comprises sodium.

7. The process of claim 6 wherein the sodium to feed sulfur mole ratio is maintained in said conversion zone at between about 2.0 and 2.8.

8. A process for the combined desulfurization and hydroconversion of a sulfur-containing residuum feedstock containing at least about 10 weight %
materials boiling above about 1050°F, which comprises contacting said feed-stock with a metal selected from the group consisting of the alkali metals and alloys thereof, in a conversion zone, said conversion zone being maintained at a temperature of above about 750°F and in the presence of sufficient added hydrogen to produce a hydrogen pressure of at least about 2000 psig. and wherein said alkali metal is present in said conversion zone in an amount such that the alkali metal to feed sulfur mole ratio is maintained at between about 1.0 and 3.0, whereby at least about 50 weight %
of said materials boiling above 1050°F are converted to lower boiling products, whereby the sulfur content of said feedstock is reduced by at least about 50 weight % and further wherein said alkali metal is at least partially converted to alkali metal sulfide in said conversion zone.

9. The process of claim 8 including the regeneration of an alkali metal from said alkali metal sulfide.

10. The process of claim 9 including separating said alkali metal sulfide from the products withdrawn from said conversion zone, contacting said alkali metal sulfide sequentially with hydrogen sulfide and a sulfur rich polysulfide in order to produce a sulfur depleted alkali metal poly-sulfide, and further wherein said alkali metal is regenerated from said alkali metal polysulfide by the electrolytic decomposition of said sulfur depleted alkali metal polysulfide.

11. The process of claim 8 wherein said alkali metal comprises sodium.

12. The process of claim 11 wherein the sodium to feed sulfur mole ratio in said conversion zone ranges between about 2.0 and 2.8.

13. The process of claim 8 wherein said feedstock contains a substantial amount of metals, and wherein at least about 60 percent of said metals are removed during said contacting in said conversion zone.

14. The process of claim 6 wherein the metal is a sodium-lead alloy.

15. The process of claim 12 wherein the metal is a sodium-lead alloy.

16. The process of claim 7 wherein a liquid product is produced whose Conradson carbon content is 35 to 100 weight percent lower than that of the feedstock.

17. The process of claim 13 wherein a liquid product is produced whose Conradson carbon content is 35 to 100 weight percent lower than that the feedstock.

18. The process of claim 8 wherein the hydrogen pressure maintained in said conversion zone ranges between about 2000 and 2500 psig.

19. The process of claim 12 wherein the temperature in said conversion zone is maintained at between about 800° and 900°F.

20. A process for the desulfurization and hydroconversion of a sulfur-containing heavy petroleum oil feedstock containing at least 10 weight % of components boiling above 1050°F, which comprises contacting said sulfur-containing petroleum oil feedstock with sodium hydride at elevated temperatures in the presence of hydrogen, the hydrogen providing a hydrogen partial pressure within the range of from about 500 to about 5000 psig., said feed-stock being maintained substantially in the liquid phase to form an oil phase having a reduced sulfur content and a reduced Conradson carbon content, and a salt phase.

21. The process as defined in Claim 20, wherein said feedstock, sodium hydride, and hydrogen are contacted at a temperature within the range of from about 500° to about 1500°F.

22. The process as defined in claim 21 wherein said feedstock, sodium hydride, and hydrogen are contacted at a temperature within the range of from about 750° to about 1000°F and the hydrogen provides a hydrogen partial pressure within the range of from about 1500 to about 3000 psig.

23. The process as defined in claim 21 wherein said feedstock, sodium hydride, and hydrogen are contacted at a temperature within the range of from about 500° to about 750°F, and the hydrogen provides a hydrogen partial pressure within the range of from about 500 to about 1000 psig.

24. The process as defined in claim 20 wherein the molar ratio of sodium hydride to sulfur content of said feedstock is within the range of from about 2 to about 2.5 moles per mole of sulfur.

25. The process as defined in claim 20 wherein said sodium hydride is present in an amount within the range of from about 1 to about 15% based on the weight of said feedstock.

26. The process as defined in claim 20 wherein said salt phase comprises a sodium sulfur salt.

27. The process as defined in claim 26 wherein said sodium sulfur salt comprises sodium sulfide.

28. The process as defined in claim 27 wherein hydrogen sulfide is added to a mixture of said oil phase and said salt phase to convert said sodium sulfide to sodium hydrosulfide.

29. The process as defined in claim 20 including the step of separating said oil phase from said salt phase, said salt phase comprising a sodium sulfide salt.

30. The process as defined in claim 29 including the step of converting said sodium sulfide salt to sodium hydride and recycling said sodium hydride.

31. The process as defined in claim 20 which includes containing at least a portion of said salt phase with a sulfur-rich polysulfide, thereby forming a sulfur-depleted polysulfide, electrolyzing at least a portion of said sulfur-depleted polysulfide, thereby producing sodium, and contactng said sodium with hydrogen, thereby producing sodium hydride.

32. The process of claim 31 wherein said sulfur-rich polysulfide is represented by the formula Na2SX where x has a value of from about 4.0 to 4.8, and said sulfur-depleted sodium polysulfide is represented by the formula Na2Sy, where y has a value of from about 3.0 to 4.3.

33. The process of claim 31 wherein said sulfur-depleted polysulfide ls electrolyzed in an electrolytic cell including an anodic compartment containing said polysulfide ions and a cathode compartment containing said sodium metal, said anodic and cathodic compartments separated by a sodium ion conduating membrane comprising beta-alumina.

34. The process as defined in claim 20 further including the step of contacting said oil phase with additional quantities of sodium hydride and hydrogen.

35. The process of claim 21 wherein the feedstock contains at least 25 weight % of the components boiling above 1050°F.

36. A process for the simultaneous desulfurization, demetallization and hydroconversion of a sulfur-containing heavy petroleum oil feedstock containing at least 10 weight % of components boiling above 1050°F, which comprises contacting said feedstock with sodium hydride in a conversion zone at a temperature ranging from 500° to 1500°F in the presence of hydrogen, the hydrogen providing a hydrogen partial pressure within the range of from about 500 to about 5000 psig., said feedstock being maintained substantially in the liquid phase in said conversion zone, to form an oil phase having reduced sulfur, metals and Conradson carbon content and a salt phase, said salt phase comprising sodium sulfide, separating said oil phase from said salt phase and converting said sodium sulfide salt to sodium hydride and recycling said sodium hydride back to said conversion zone.