CA1125212A - Catalyst and process for hydroconversion of hydrocarbons using steam - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A process for the steam hydroconversion of light hydrocarbon feed stocks relatively deficient in hydrogen and high in sulfur, which process comprises passing the feed and steam into a steam hydroconversion zone over a dual-function catalyst comprising molybdenum on a high surface area alumina base or on an iron oxide-chromium oxide base, said catalyst having been reduced and sulfided prior to use. A portion of the hydrocarbon is steam reformed to produce hydrogen in the reaction zone which is then used in situ to hydrogenate the olefins and aromatics in the feed and also removes sulfur therefrom, all processes occurring in the same reaction zone.

Description

r - ~
~Z52 1 ~AC~C~O~N3 Dr I~E I~V~ O~

2 Field of the Invention ~_, .

3 This lnvention relates to a combination steam

4 reforming-hydroconversion process for ligh~ hydrocarbon .
feeds wherein the hydrocarbon and s~eam are passed over a 6 sulfur-resistant catalyst which performs the dual fu~ction 7 of steam reforming and hydroconversio~ of the ~eed. More ~ particularly, this invention re~.at2s to a process for steam g reforming and hydroconverting a rela~iYeiy light hydrocarbon that is rslatively lcw in hydrogPn and high in sulfur, whlch 11 comprises passing steam and the hydrocarbon over a sulfur~
12 resistant catalyst ccmprising moLybde~um on a base selected 13 from the group consisting of {a) a high surface area alumina 14 base or (b) an iron oxide-chromium oxide base, said cata- :
lyst having been redu~ed and sul~ided prior to use, whereby 16 the steam reformin~ and hydroconversion are achieved in the 17 same reaction zone. --18 Desc on o~ the Prior Art_ 19 Steam reforming is well known to those familiar in the ar aa a process or prod~cing hydrogen or hydrogen~
21 con~aining gas mixtures by conver~ing hydrocarbons with 22 steam. The hydrocarbon reac~s wi~h steam to form carbon 23 monoxide and:hydrogen in a gasifLcatLon reaction. The c~r~
i 24 bon monoxide is then reduced to a low level by a water gas ~ 25 shi~t reaction, whLch also produces more hydrogen. The two $'~

1 reactions combine i~ steam reforming as illus~rated by the 2 following equaticns.
3 Ste~m re~orming: CnH2n ~ 2nH2o -~3nH2 ~ nC2 4 3 a) gasificationo CnH2n ~ n~2~ 2nH2 -t nCO
S + ~ wate~ ~s shit: nCO + nH2O-~ nH2 ~ nC02 6 O~e of the more commonly used catalysts for 7 stesm reorming is nickel oxide. NickPl oxide catalysts 8 are very reactive and steam resistant. Unfortunately~
~ however, ~hese catalysts are not rasistant ~o sulfur and, consequently, their catalytic ac~ivity rapidly diminishes 11 to an unacceptably low level in the presen e o~ sulfur~
12 containing hydr~c~rb~ns. Pla~int~ and other noble metal 13 containing catalysts are also quite active for s~eam 14 re~rming hydr3carb~n fractions, but these too are rapidly 15 poisoned by relatiYely sm~ll qu~ntities of sulfux in th 16 feed. Cataly~ts cos~nonly llsed for the w ter gas shift 17 reaction include ironJc~romi~ ~xide and zinc/copper oxide 18 catalysts, while ~he m~re efflcien~ hydr~genation ca~aLys~s 19 con~ain one or more noble ~e~als. Tnese catalysts are also poisaned and de c~l~ated by sulfur. ~nfort~cn~tely, ~any o 21 ~he well known sulfur tolerant hydrogen t~on catalysts are 22 deacti~ated i~ the presence of stea~ and are therefore 23 totally ~nsui~ ble ~n th~ stea~ reforming process.
24 ~ :The petroi~u~ lndu~t~y i5 incr~a3inOly turning to:co~ r sands and ~ea~y crudes a~. sources f~r fu~ure 26 raw materi~LsO Feed stccks de~ived fro~ th~se heavier .
27 m~terials are quite naturally ~e2~ie~ but k~e~ are also 28 more hydrogen deficient ~nd ~Ligher in ~ulfur ~nd nitrogen 29 than eed stoc~cs derived fr~-L~ ~ore corlver~ti~nal crude oiLs.
Thes~ heavier~eed 9~0cks tberef~re req~ire a considerable :

5~ ~

amount of upgrading to usable products, such upgrading being accomplished by various hydroconversion reactions such as hydrodesulfurizing and hydrogenating, both of which require large volumes of hydrogen and consequently result in very high processing cos~s. One way of processing such feeds is to pass the sulfur-containing feed to a first zone wherein sulfur is removed via contact wi~h a hydrodesul~urization catalyst, followed by a steam reforming zone wherein the desulfurized feed is contacted with steam and a catalyst to convert a minor portion of the feed to hydrogen, followed by passing the feed and hydrogen from the steam reforming zone to a third zone wherein the unsaturated portions of the feed are saturated by catalytic hydrogenation. Further, steam reforming is endothermic in nature requiring heat input to the reaction zone, while hydrogenation is exothermic.
It is apparent therefore, tha~ i~ would be a signi-ficant improvement to the art if one could develop a process and steam and sulfur-resistant dual-function catalysts which would permi~ combining the endothermic hydrocarbon-steam reforming reaction to produce hydrogen and, at the same time, allow in si~u utilization of the hydrogen pro-duced by the steam reforming to saturate the olefins present in the feed and hydrodesulfurize same, all in the same re-action zone. This would eliminate the need for a separate source of hydrogen, eliminate the need for the plurality of reaction zones heretofore required for such processing and also result in substantial energy savings, because the exothermic hydroconversion reactions would provide at least a portion of the heat required for the endothermic steam reforming. ~`

~1 , b~Y~~
2 It has now been discovered that one can achieve a 3 process combining hydrocarbon s~eam reforming and hydrocon-4 version processes for sulfur and ole~in containing, light 5 hydrocarbon feed streams wherein the processes all occllr in

6 the same reac~ion zone, which comprises passing steam and the

7 hydrocarbon feed into a steam hydroconversion zone over a

8 dual-function catalyst comprising molybdenum o~ a base selected

9 rom the group consisting of (a) a high surface area alumina base and (b) an iron oxide-chro~ium oxide base, said cataly$t 11 having been reduced and sulfided prior to use. Essential to the 12 understanding and practice of this invention is the fac~ that 13 no external hydrogen needs to be added to the steam hydro-14 conversion zone. Hydrogen is produced in the steam hydrocono version zone via an endothermic hydrocarbon-s~eam reforming 16 reaction and this hydrogen so produced is used in situ to 17 saturate olefinspresent in the feed and hydrodesulfurize same.
18 For the sake of brevity, ~he combination of steam reforming 19 and hydroconversion processes~ both of which occur in the same reaction æone (steam hydroconversion zone) will hereinafter 21 be referred to as steam hydroco~versionIt has also been 22 discovered that the addition of minor amounts of alkali or 23 `al~aline earth metals to the catalyst will greatly improve 24 its life.
By steam re~orming is meant the combina~ion gasifi-26 ca~ion plus water gas shit described supra, wherein o~efins 27 in the hydrocarbon stream react with steam to produce carbon 28 dioxide and hydrogen. Hydroconversion processes refer to 29 hydrodesulfurization of the feed and hydrogenation of the un-saturated olefins present therein, along with some mild hydro-31 cracking and attendant hydrogenation o the hydrocrackate and ~ ~ ~52~

1 wherein ~he hydrogen consumed is that produced by the steam re-2 forming reaction. The following equations illustrate the steam 3 hydroconversion (steam reforming plus hydroconversion) of 4 propylene to form propane, wherein the maximum ~heoretically obtainable yield at 100% conversion is 90 mole % of propane.
6 (a) steam reforming C3H6 ~ 0.6 H20 ~ 0.9 C3H~ ~ 0.3 C02 + 0.9 H2 8 (b) hydrogenation 3 6 0.9 1~2 ~ 0.9 C3H8 ~c) overall 11 C3H6 ~ 0-6 H20 --~ 0.9 C3H8 ~ 0.3 2 12 Catalysts useul in ~he process of the instant 13 invention c~mprise dual function stean hydroconversion 14 catalysts that are resis~ant to both steam and sulfur, said catalysts comprising molybdenum alone or in admixture with 16 cobalt as the active catalytic metals on either a high 17 surface area alumina base or on an iron o~ide-chromium 18 oxide base, said catalyst having been reduced and sulfided 19 prior to use. Additionally, it has been found that the efective life o~ the catalyst is greatly increased if 21 the catalyst is promoted wi~h small amounts of one or . ....
22 more alkali and/or alkaline earth metals.
23 Although it is pre~erred that the catalytic metals 24 initially be present on the catalysts as sulfides, said metals may also initially be present on the catalyst as oxides, re-26 duced forms of the metal or as mixtures o these and othex 27 forms. What is important to the operation of the instant : .
28 invention is that the catalytically active metals be converted 29 to the sulfide form either in t~e manufacture of the catalyst, .
by pretreating same prior to its use in the operation o the 31 instant~inven~ion or by in sit~ conversion of the oxide or 32 reduced fonms to the sulfides via sulfur-containing feeds.

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

1 These metals will be present ~n the catalysts in ~ catalytically active amo~s3 e.g., from about 5 to about 50 3 wt. % (calculated as metal), pre~erably ~rom about 10 to 40 4 wt. % and most preferably ~rom about 15 to 30 wt. % based on the total weight of ~he catalyst when the activ me~al is 6 molybdenum. Particularly preferred cat~lysts include 7 (a) about 25 to 50 wt. % molybdenum sulfide and (b) 15 ~o 8 30 wt. % molybdenum sulfide along with 2 to 10 wt. % cobalt 9 sulfide based on the total weigllt (dry basis) of ~he catalyst

10 cornposition.

11 The exact method used to sulfide ~he catalyst is no~

12 importan~ and the art recognize5 several ways in which one

13 may sulfide such ca~alysts. Xllustrative examples include

14 (a) using hydrogen suLfide with hydrogen~. (b) using carbon disulfide with hyd~age~ or in a hydrocarbon feed in the pres-16 ence of hydrogen and (c~ using a sulur-containing feed in 17 a ~educing atmosphere~ .
18 In addition to the catalyticall!y ac~ive ~etal com-19 ponents, t~e catalyst may also contain minor amounts o other Group VIB and VIII metals such as tungsten, platinum, rheniumJ
21 and nickel which,while not necessarily catalytically active 22 in the instant invention, ha~e been found not to exert a 23 deleterious effect to the operation of same. As much as 5 24 wt. % of these other metals may be present on the catalyst 25: without incurring any deleterious ef~ect.
26 The ratio of molybdenum to cobaLt.in catalysts 27 containing both of these metals generally ranges rom 1.5/1 28 to 20/1,~ preferably 3~5/1 ta 10/1 and most preferably rom 29 4.5/1 to 8.5/1. If minor amounts of other group VIB or VIII ~ -30 metals are present, the ratio of molybdenum to these other 31 metals will gene~al:ly range ~rom about 50/1 to 5/1 and pre-32 ferably rom 25/1 to 10/1.

1 The alumina support material employed in the cata-2 lysts of ~his invention is most preferably a high surface 3 area type of alumina having a surface area of from about 100 4 to about 400 m2/g (s~uare meters per gram) and most prefer-ably ~rom about 150 to abou~ 350 m2/g. A particularly pre-6 erred alumina support is eta alumina having a surace area 7 of approximately 300 ~2/g, Although the presence o~ silica 8 in the al~nina support is detrimental to the process of the 9 ins~ant invention9 the support may contain up ~o about 5 wt~C/o sili~a (based on the total weigh~ of the support) without in-11 cur~ing any serious adverse effects to the processes of the 12 instant invention. As hereinbe~ore stated, supra, the cata 13 lyst life is greatly ~mproved by ~he addition of minor 14 amounts of alkali a~d/or alkaline earth me~als illustrated by, but not limited to, metals such as barium and cesium~ In 16 general, these metals will range from about 1 to 10 wt. %
17 (based on total catalyst weight~, and pre~erably from about 18 2.5 to about lOZ~ The alkali and/or alka~ine eart~ metals 19 are ge~eralIy incorporated into the catalyst base in the form of acetates or carbonates.
21 A particularly preferred catalyst useful in the 22 process of the instant invention comprises from about 25 to 23 about 50 wt. ~/a molybdenum sulfide and from about 2 to 8 wt~/o ~4 cesium carbonate based on the to~al weight (dry basis~ of the catalyst, supported on an eta alumina base.
26 The iron oxide-chromium oxide base or support will 27 contain from about 1 to 15 wt. % chro~ium oxide (calcula~ed 28 as Cr203) with most of ~he balance being iron oxide (calcu-29 lated as Fe203). These supports are of the type in U.S.
30 2,662,063, the disclosures of which are incorpora~ed herein 31 by reference. The surface area o this type of support 1 generally ranges around 100 m2/g. A preferred cataLyst 2 useful in this inven~ion will comprise from about 20 to 3 30 wt. % molybdenum (based on ~otal ca~alyst weigh~, dry 4 basis) on the iron oxide-chromium oxide support.
~ The steam hydroconversion catalysts of the ins~ant 6 invention may be preDared by any conventional manner known 7 in the art. For example, a commercial alumina catalyst base 8 of the desired surface area may be soaked in a solution of 9 ammonium molybda~e CGrl~aining the de~ired amount o~ molyb~
denum. The water is removed in a ~lash evaporator and the 11 resulting catalyst is dried at 230F. and calcined in air at 12 about 930F. Prior to use in the laboratory, it has been 13 found convenien~ to reduce and sulfide the molybdenum by 14 passing a mixture of 10% H2S in hydrogen over the catalyst at about 930F. Up to 50% iner~ gas may be added i~ this 16 last step to prevent overheating due to the exothermic 17 nature of the reaction.
18 The iron oxide-chromium oxide support may be pre-l9 pared by coprecipitating a mix.tur~ of chramous an~ ferrous hydroxides by the addition of sodium hydroxide solution to 21 an aqueous solution o errous sulfate and chromic acid 22 containing the desired amount o~ iron and chromium. The 23 hydroxide precipitate is air dried at up to ~bout 1100F
24 dùring which time the hydroxides are oxidized to chromic and ferric oxides. The resulting material may be pelletized 26 or extruded by standard methods. Molybdenum is then deposi-27 ted on this base by the method described above for the 28 alumina base and the resulting catalyst calcined, reduced 29 and sulfided as previously described. During the suliding 30 step the chromium and iron oxide ma~ also be converted to .. :
31 their sulfides. Alternatively, the chromium oxide may be 32 deposited on the iron oxide.

_ 9 _ 1 In accordance wi.th the instant invention, the 2 aforedescriLed ca~alysts are employed to steam hydroconvert 3 li~ht, sulfur containing feed stocks by contacting said 4 feed stocks with the catalyst in the presence of steam at a temperature in the range of from ~out 500 to 1200F. and 6 preferably 750 to 1000F~; a pressure in the range of from 7 about 0 to 1000 psig and prPferably O to 600 psig; a steam 8 to hydrocarbon mole ratio of from about 0.5 to 10 and pre-g ferably 1.5 to 6.5, with a gaseous hourl~ s~e~e velocity 10 (V/V/Hr . ) in the range of from about 20 ~o 200 and pre~er-11 ably from about 40 to 150 Y/V/Hr.
12 Hydrocarbon feeds useful in the process o the 13 instant invention are the relatively li~h~er pctroLeum fractions containing unsa~urated olefins, ranging Xrom those

15 hydrocarbons normally gaseous at room ~empera~ure and pres-

16 surey such as propylene~ through light, steam cracked naph-

17 thas having a boiling range of from about 140 to 200F. up

18 to an including feeds such as coker naphthas boiling in the

19 rang,_ of from about 140 to 4 00F. In general, these feeds

20 may have sulfur contents up to about 0.5 wt~ % and may h~ve

21 levels of unsa~uration such that the Bromine Number ranges

22 from about 50 to 200. However, both the sul~ur content and

23 unsaturation ma~ be appreciably higher as evidenced by the

24 fact that the catalys~s of the instant invention were ef-

25 fective in steam hydrocon~erting propylene to propane in the

26 presence of 4 wt. % H2S. Propylene has a theoretical

27 Bromine Number of 380. Further, feeds derived from the ~8 heavier materials such as heavy crudes, tar sands, shale oil, ~9 coal, etc. will contain considerably msre unsaturated olefins 30 and sulfur than those deri~ed from more con~entional crude 31 oils. Klthough feed stocks rela~ively low in sulfur or 32 containing no sulfur at all may be steam hydroconverted with 1 the catalysts of ~his inventiona one of the ou~standing 2 features of same is the ability to steam hydroconvert feeds 3 containing over abou~ 50 ppm of sulfur by using a single, 4 dùal-function catalys~ with both the steam reforming and hydroconversion processes taking place simultaneously in 6 the same reaction zone without having to add any external 7 hydrogen to the reac~ion zone.
8 DESC~IPTION OF T~IE PREFERP~ED ~i30DL~IENT
9 The following examples urther lllustrate the present invention. Unless othe~ise specified, all pex-11 centages and parts are by weigh~.

13 Steam hydroconversion cata].ysts in accorclance with 1~ the invention were prepared as follows:
A number of com~ercially available catalysts 16 ~listed in:Table 1) were impregnated with various amountc 17 Of metals, including rhodium, moIy~denum and rhenium as 18 shown in the Table, by soaking same in aqueous solutions of lg the desired metal5 followed by flash evaporation ~f the water and air calcLning for one hour at gOOF~ Some of the cata-21 lysts were not modifled~ while the rhenium on alumina cata-22 lys~ used for run 21 was prepared by soaking a commercial .
23 alumina in a solution of rhenium trichloride followed by 24 flash evapora~ion of the water and air calcining for one hour at 900F. All of the catalysts were reduced and sul~
26 fided by contact with a 10/1 mixture of H2/H2S for one hour, 27 or until H2S breakthrough, at a tempera~ure of 900F. ~nd

28 atmospheric pressure in order to convert the catalytic metals

29 thereon to the sulfide form. During sulfiding it was occas-ionally necessary to dilu~e the H2IH2S mixture with an inert 31 gas in order to maintain the temperature at 900F., due tO
32 the exothermic na~ure of the reaction.

~.~L2~
- 1 1 ~
l T~e sulfided catalysts were then contacted with 2 steam and a propylene stream containing 4~/O H2S in the ratio 3 of 4/l steam/propylene, at a t~mpera~ure in the range o 4 750 to 950F., at atmospheric pressure and a space velocity o 120 V/V/Hr. T~e H2S was added to ~he ~eed in order ~o 6 determine the resistance of the various catalysts to sulfur 7 and amounted to 40,000 ppm of sulfur in the hydrocarbon Feed 8 stream.
9 Table 2 contains t~e resu].~s o~ ~he experiment 10 which are expressed as the percent o~ propane in ~he ofi or 11 product gas~ The noble metal and rhenium catalysts, both 12 o~ which are use~ul ~or steam reforining, t~ere relatively 13 ine~fective, while the molybden~n containing catalysts 14 operated e~feci:ively in the sulfur containing strea~ and steam hydroconverted some of the propylene to propane.

19 ~lm . . .
20 No.Catalysts and C m~ sitionsa 21 1Cyanamide CK-303 (0.3% Pt. on A12O3~ Impregnated 22 with 0.3% Rh~
*
23 2 Nalco 471A (3~5% CoO and 12.5% MoO3 on A1203).
24 3 Girdler T-828 (2~5~/o NiO, 3% CoO and 10% MoQ3 on 26 llGirdler G-3A (l~/o Cr203 on Fe203) Impregnated 27 with 10% ~o.
28 12Girdler G 3A (10% Cr2O on Fe2O ) Impregnated 29 with 25/~ Mo. 3 3

- 30 13Girdle~ G~3A (10% Cr2O3 on Fe203) Imp~egna~ed

31 with 5% Mo.

32 19Harshaw Mo-1201 (l~/o I~1003 on A1203)-

33 212% Re on A1203.

34 283, 5/0 CoO and 14% MoO3 on A1203 Notes: a Metal con~ent as oxide based on total.catalyst 36 composition.
* TM
..~

Tab 2 EFFECTIVENESS OF CATALYS~S IN
3 STEA~ HYDROCONVE~TIMG PROPYLENEb 4 ~W ~

All catalysts reduced and sulided in 10/1 H2~H2S pFior to useO.

7 ~un N~.a ~ C3~,C~
8 1 1.1 3 7.6 11 ll 7 .
12 8 . 3 13 13 7 . 5 14 19 `.7.8 . ~
21 2.2 .
28 13 . 7 7 No~es- a Ca alyst compositions correspond eo ~hosa in 19 b 4 w~.~Z H~S in ~propylene feed~
.
2.1 In ~his experiment, as in ~Example 1, supra, a 22 number of comstercially a~aiLable catalyst suppoxts or :bases 23 were impregnated wit~ 25% molybden~m which was then reduced, 24 sulfided and contacted with ~ the same feed stream and at the 25 same conditions as in Example 1. The results are shown in 26 TabLe 3 and suggest tha~ m~re e~fective stea~h hydroconver-27 sion oP propylene to propane is obtained if one employs 28 both higher sur~ace area s~ippcr~s and snp~orts ~'~at are 2~ primarily alumina.: The ;~ost ef~ective catalyst in this :

, .. ... .

~ 13 -1 experiment was 25~ molybdenum on eta alumina.

Table 3 425% molybdenum reduced and 5sulfided on support 6Sura~e Area % Propane in 7 ~ ~ Product Gas_ 8 Davison 970 (87/13 SiO2/A1203) 100 3.5 ;~
9 Harshaw*Al-3428 (A1203) - 176 19~3 Davison (~ oA1203~ 300 24.7 11 ~, 12In this experimen~ samples of the 25% molybdenum 13 on e~ alumina c~talys~ were impregnated with alkali and 14 alkaline earth me~als by sc~ing the molybdenum on ~lumina catalyst in an a~ue~us solu~ion of ~he acetate, carbona~e 16 or hydr~xide o~ the alkali or alk21ine earth~metal which 17 contained t~e desired amount o~ metal, removing the~water 18 by flash evaporation and drying and calcining the impreg-19 nated catalysts at temperatures up to 500~C (930F~ Lor one hour in air.

2L Table 4 22IMPRO~E~N~ OF GATALYST LIFE BY AD~ITION OF
~3ALKAIX AND ALI'~LINE E~RT'~ ~TAL5 _ __ 24 Added Metal1. _ c~_ ~c~ l~
~ ~None 37 26 5% ~ 2~ -:
27~ SZ Cs 13 28 ~.5% Cs ~ 20 29 The impregnated catalysts were reduced and sul~ided using * TM

.... . ~ ' "

~ $

1 the method ou~lined ~n ~xample 1. The sulfided catalysts 2 were then contacted wi~h a 3/1 steam/propane feed stream 3 a~ about 750~, atmospheric pressure and a space velocity 4 of about 60 V/V/Hr~ The effect of th~ alkali and alkaline S ear~h metals was determined by measuring ~he loss of 6 catalytic activity for steam hydroconverting the propylene 7 to propane after between 3/4 and 2-1/2 hours onstrPam.
8 The results in Table 4 show that bo~h alkali and 9 alkaline earth me~als are effective in improving ~he catalyst life.
11 ~,~ , 12 This illustrates the effectiveness a the inven-13 tion in steam hydrocon~erting a sour, steam cracked naphtha.
14 A 10% molybden~m on ~ alumina catalys~ sold commercially ~:
by the Harchsw Chemical Company as Mo~1201 for hydrogena~
16 tion, dehydrogenation and hydroforming was utilized. This 17 catalys~ could be prepared by soa~i~g alumina of desired 18 surface in æmmoniu~ molybdate solution followed by flash 19 evaporation of ~he water and drying ~nd calcining in air.
The catalyst was reduced and sulfided prior to 21 use according to the procedure outlined in Exampla L. It 2~ was then contacted with a sul~ur~containingS saur, steam 23 cracked~naphtha feed at a temperature of:950F9 a pressure 24 ~of 600 psig, normalized space velocity of 140 V/V¦Hr~ and a steam/~eed mole ratio of 4/1. The results given in ~6 Table 5 show a substantial decrease in b~th sulfur content 27 and Bromine Number~ i ~Table 5 2STEAM HYDP~OCONVERTIt.~G
3SOTJr~ STEAI~I C~CI~ED ~7AP~ITHA
__ ____ 4 Feed Product 5Sulfur, ppm 500 250 6Bromine Number 90 20 ~ ~ .
8. ~his illustrates the effect o~ different space 9 velocities and steam mole ratios cn ~he steam hydroconver-lQ sion o propylene to propaneO
11 A 25% molybdenum on eta alumina ca~alyst was 12 prepared by the method o~ E,v.ample 3. Propylene and steam 13 i~ varying mole ratios were passed o~er the cat~lyst at 1~ atmospheric pressure and-750F. The pl:opylerP eed con-~ailled 4% H2S. T~ble 6 ~Plow sho~?s that highest )T~e~ds 16 of propane were obt2ined at a ~aseous hourly space 17 velocity o 120 when the mole ratio of steam to prop~rlene 18 ~as 1.5. Simllarly high yields wPre obtained at a low 1~ space velocity of 40 V/V/Hr ~hen 6.5 m31ec of steam were added. The catalyst was regenerated with air &nd resul-21 ~ided between each different conditior10 22 Table 6 23 C3 Space Velocity H20/C~ ~/O Propane 24 V/V/~ ~ole l~atio in ~roduct .
120 ~ 10,7 26 " 4 24.7 27 " 2 26.?
28 " 1.5 3~.9 29 " 0.8 30.
~40 6.5 39.9 .. . ... .

, ~ 16 -1 ~
2 This illustrates ~he efect of pressure on the 3 steam hydroconversion of propylene to propane.
4 A 25~ molybdenum on eta alumina catalyst was pre-S pared as previously descr~bed. Propylene containi~g 4%
6 sulfur as hydrogen sulfide or butylmercaptan was passed 7 over the catalyst at 750F at~tmospherie pressure and at 8 300 psig. Table 7 shows the conversion of propylene, 9 selectivi~y of the reac~ion to propane and propane yields when operating at 40 V/V/Hx at a~mospheric pressure and 1} 120 V/V/Hr at 300 psig.

12 ~a~

13 H20/C3- Propylene Propane 14 Press C~' Sp Vel Mole Conver- Selec~ Propane E~ V7VJHr Ratio ~ y~_~ Yield %
16 0 40 6.5 65~5 65~2 42.8 17 300 12~ 6.5 98.0 7805 77~0

Claims (28)

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

1. A process for the steam hydroconversion of a light hydrocarbon feed stock boiling below about 400°F. and containing olefins and sulfur compounds to desulfurize said feedstock and hydrogenate said olefins in the absence of add-ed hydrogen, said process comprising passing said feedstock and steam into a steam hydroconversion zone over a dual func-tion catalyst comprising molybdenum on a base selected from the group consisting of (a) a high surface area alumina and (b) a mixture of iron oxide and chromium oxide, said cata-lyst being sulfided prior to use.

2. The process of claim 1 wherein the catalyst contains a minor amount of one or more metals selected from the group consisting of alkali metal, alkaline earth metal and mixtures thereof.

3. The process of claim 2 wherein the amount of catalytically active metal ranges from about 5 to 50 wt. %
based on the total weight of the catalyst.

4. The process of claim 3 wherein said minor amount of alkali metal, alkaline earth metal and mixtures thereof ranges from 1 to 10 wt. % based on the total weight of the catalyst.

5. The process of claim 4 wherein the catalyst contains from 25 to 50 wt. % molybdenum sulfide.

6. The process of claim 5 wherein the catalyst contains from 15 to 30 wt. % molybdenum sulfide and from 2 to 10 wt. % cobalt sulfide based on the total weight of the catalyst composition.

7. The process of claim 5 wherein said alkali metal, alkaline earth metal and mixtures thereof is selected from the group consisting of cesium and barium.

8. The process of claim 7 wherein the surface area of the alumina base ranges from 100 to 400 m2/g.

9. The process of claim 8 wherein the base is ?-alumina having a surface area of about 300 m2/g.

10. The process of claim 3 wherein said feed contains at least about 50 ppm of sulfur.

11. The process of claim 10 wherein the olefin content of said feed is such that the bromine number thereof is at least about 50.

12. The process of claim 11 wherein said feed boils within the range of from about 140°F. to about 400°F.

13. The process of claim 12 wherein the catalyst comprises from about 20 to 30 wt. % molybdenum on an iron oxide-chromium oxide base containing from 1 to 15 wt. %
chromic oxide.

14. A steam hydroconversion process for desulfur-izing and saturating olefins, wherein the olefin content of:
said feed provides for a bromine number of at least about 50, in a light hydrocarbon feed wherein said feed boils below about 400°F., and contains sulfur and olefins which comprises passing steam and said hydrocarbon feed, in the absence of hydrogen, into a steam hydroconversion zone over a dual-function catalyst comprising molybdenum on a base selected from the group consisting of (a) a high surface area alumina base and (b) an iron oxide-chromium oxide base and wherein said catalyst is sulfided prior to use.

15. The process of claim 14 wherein said catalyst contains from about 1 to 10 wt. % of metal selected from the group consisting of alkali metal, alkaline earth metal and mixtures thereof.

16. The process of claim 15 wherein the feed boils within the range of from about 140°F. to about 400°F.

17. The process of claim 16 wherein the feed con-tains at least 50 ppm of sulfur.

18. The process of claim 16 wherein the olefin content of said feed is such that the bromine number thereof is at least about 50.

19. The process of claim 18 wherein the amount of molybdenum sulfide on the catalyst ranges from 25 to 50 wt. %.

20. The process of claim 19 wherein the catalyst comprises from 25 to 30 wt. % molybdenum sulfide and 2 to 8 wt. % cesium on an ?-alumina base.

21. The process of claim 17 wherein the catalyst contains 15 to 30 wt. % molybdenum sulfide, 2 to 10 wt. %
cobalt sulfide and 2 to 8 wt. % cesium on an alumina base having a surface area of from 150 to 350 m2/g.

22. A steam hydroconversion process for desulfur-izing and saturating olefins in a light hydrocarbon feed boil-ing below about 400°F. and containing at least 50 ppm of sul-fur which comprises passing steam and said hydrocarbon feed into a steam hydroconversion zone, in the absence of added hydrogen, over a dual function catalyst comprising 20 to 30 wt. % molybdenum on an iron oxide-chromium oxide base wherein the amount of chromium oxide in the base ranges from 1 to 15 wt. % calculated as Cr2O3, said catalyst also containing from about 1 to 10 wt. % of metal selected from the group consisting of alkali metal, alkaline earth metal and mixtures thereof and wherein said catalyst is sulfided prior to use.

23. The process of claim 22 wherein the steam and light hydrocarbon feed are fed into the steam hydroconversion zone in the absence oh hydrogen.

24. The process of claim 11 wherein the feed con-sists essentially of a mixture of propylene and H2S.

25. The process of claim 19 wherein the feed con-sists essentially of a mixture of propylene and H2S.

26. The process of claim 21 wherein the feed con-sists essentially of a mixture of propylene and H2S.

27. The process of claim 23 wherein the feed con-sists essentially of a mixture of propylene and H2S.

28. The process of claim 23 wherein said feed boils within the range of from about 140°F. to about 400°F.