HYDRODEMETALATION AND HYDRODESULFURIZATION USING A CATALYST OF SPECIFIED MACROPOROSITY
BACKGROUND OF THE INVENTION The present invention relates to hydrodemetalation and hydrodesulfurization and to catalysts useful for simul- taneously carrying out hydrodemetalation and hydrodesul- furization of a heavy oil feedstock. The invention relates to catalyst of certain pore characteristics, especially macroporosity characteristics, which have been found to be surprisingly effective in simultaneous hydrodesulfurization and hydrodemetalation of heavy oils.
U.S. Patent No. 3,898,155 discloses a process for simul- taneous demetalation and desulfurization of heavy oils containing at least 50 ppm metals under hydrogenation condi- tions using a catalyst composition comprising a Group VI metal and at least one Group VIII metal composited with a refractory oxide. The catalyst has 10 to 40 percent of its pore volume in macropores and from 60 to 90 percent of its pore volume in microporeε, at least 80 percent of the micro- pore volume being in pores having a diameter of at least 100 A units, said catalyst composition further having a total pore volume of at least 0.5 ml per gram, an average pore diameter greater than 100 A units, and a surface area of at least 100 square meters per gram.
Taiwanese Patent No. NI 23,976, issued April 16, 1986, dis- closes a process for demetalation and desulfurization of asphalt containing hydrocarbons under hydrogenation condi- tions employing a catalyst comprising molybdenum, at least one Group VIII metal, and alumina, the catalyst having a total pore volume based upon measurements by mercury penetration of at least .4 cc per gram, a macropore volume
in the range of 5-50% of catalyst pore volume, and a meso- pore volume of at least 0.12 cc per cc of catalyst volume.
U.S. Patent No. 4,008,149 discloses a catalyst for use in hydrodesulfurization, hydrodemetalation and hydrodenitri- fication. The catalyst has a 250 to 300-m2/g surface area, at least 80 percent of the pore volume in the range 0 to 150A, is from pores from 60 to 150A; less than 0.01 illi- liters per gram of pore volume is from pores in the range 150 o 2000A; and the volume of the pores in the range 0 to 600A is between about 0.45 and 0.60 milliliterε per gram of catalyst.
U.S. Patent No. 4,301,037 discloses a bimodal alumina catalyst support having most of the surface area in a micropore region having pores of less than 500A, and also having a macropore region having pores with diameters of lOOOA to 10,000A.
u.S. Patent No. 4,225,421 discloses a bimodal catalyst for use in hydrodemetalation and hydrodesulfurization of a hydrocarbon feedstock containing asphaltenes and metals. The catalyst contains one active hydrogenation metal selected from Group VIB deposited on a support comprising alumina. The catalyst has a surface area within the range of about 140 to about 300 m2/g, a total pore volume based upon measurement by mercury penetration within the range of about 0.4 cc/g to about 1.0 cc/g, and comprising about 60% to about 95% of its micropore volume in micropores having diameters within the range of about 5θA to about 200A, 0% to about 15% of its micropore volume in pores having diameters within the range of about 200A to about 600A and about 3% to about 30% of said total pore volume based upon measurements
by mercury penetration in macropores having diameters of 600A or greater.
U.S. Patent No. 4,454,026 discloses a hydrotreating catalyst comprising a hydrogenating component and a support comprising at least one porous refractory inorganic oxide, the catalyst having a BET surface area of 150 to about 190 m2/g, bulk density of at least about 0.2 grams per cc, total pore volume of at least about 0.9 cc/g with mercury pene- tration pore volume of at least about .1 cc/g and macropores with radii of 600 to 25,000A, such surface area, pore size distribution and total pore volume being effective to give an average pore diameter of at least 230A, calculated as 4 times the pore volume over the surface area.
SUMMARY OF THE INVENTION According to the present invention, a process is provided for hydrodemetalation and hydrodesulfurization of a high-boiling point hydrocarbonaceous feed, which process comprises contacting the feed in the presence of hydrogen gas and at a temperature between 600°F and 1000°F and a pressure between 100 and 10,000 psig with a catalyst com- prising a hydrogenation component selected from Group VI and Group VIII metals, and an inorganic oxide refractory support, and wherein the catalyst has
a. 5 to 11 percent of its pore volume in the form of macropores, and
b. a surface area greater than 75 m2/g of catalyst.
Preferably, the catalyst also has an average mesopore diameter greater than 16θA. Still further, preferably the
catalyst has a peak mesopore diameter greater than 165A as determined by mercury porosimetry.
Among other factors, the present invention is based on our finding that surprisingly good hydrodemetalation (HDM) and hydrodesulfurization (HDS) of heavy oil feedstocks are achieved using a catalyst wherein the macropore volume is within the relatively narrow range of 5 to 11 percent of the total pore volume of the catalyst, preferably within the range 6.5 to 10 percent of the pore volume of the catalyst, and the catalyst has a substantial surface area, above 75 m2/g, preferably above 100 m2/g, most preferably above 115 m2/g. Also, we have found particularly good HDM and HDS is achieved when the catalyst has a peak pore diameter greater than 165A, more preferably, greater than 185A as measured by mercury porosimetry and an average mesopore diameter greater than 160A, preferably greater than 180A.
After extensive research, we have found that catalysts with lower macropore volume may have attractive hydrodesul- furization activity, but relatively lower hydrodemetalation activity and metals capacity. Further, we have found that when macroporosity is above the range for the catalyst used in the present invention, good hydrodemetalation activity and metals capacity may be maintained, but the sulfur removal activity drops off relatively rapidly. Also, when the macroporosity is greater than the range of the catalyst used in the present invention, the Conradson carbon [a measure of coke forming tendency, also expressed as Microcarbon Residue (MCR)] reduction ability of the catalyst drops off rapidly as a function of time.
Although the present invention is not to be limited by any theory of operation, a possible explanation in view of our
findings is as follows: at low macroporosity (for example, below 6.5 percent, and especially below 5 percent), organo- metallic molecules cannot easily diffuse into the catalyst particle and react. Hence, the low activity and metals capacity for the low macroporosity catalyst. At high macro¬ porosity, organometallic molecules more easily can diffuse into the catalyst particle. However, "poisons" in the feed also diffuse into the particle and deactivate the active sites for sulfur and MCR removal. We have found that at a macroporosity between 5 and 11 percent, and especially in the range 6.5 to 10 percent, there is a desirable balance in the hydrodemetalation activity and hydrodesulfurization activity as well as MCR removal activity. Organometallic molecules can diffuse relatively readily into the particle, but the "poisons" cannot as readily diffuse into the cata- lyεt. Therefore, the catalyst has good hydrodemetalation activity and metals capacity as well as good activity for sulfur and MCR reduction. The "poisons" mentioned here are not well-defined, but are believed to be high-molecular weight molecules, possibly containing metals.
using catalysts that are in accord with Taiwanese NI 23,976, provides good hydrodesulfurization and hydrodemetalation activity. However, use of the catalysts in accordance with the present invention has been found to provide generally superior combined hydrodesulfurization and hydrodemetalation activity. Catalysts in accordance with the aforementioned Taiwanese patent had a relatively large amount of macropore volume to achieve good hydrodemetalation activity and metals capacity. The catalyst had in the range of 25% of its pore volume from macropores. In order to achieve good hydro- desulfurization activity, perhaps requiring the exclusion of poisons from the catalyst pellet interior, the catalyst, in accordance with the Taiwanese patent, had mesopores which
were relatively small, namely, about IIOA. It is theorized that the relatively small mesopores were a main reason for the relatively lower hydrodemetalation activity compared to the hydrodemetalation activity achieved using catalyst in accordance with the present invention. This is illustrated further hereinbelow by Example 8.
various methods may be used to make the catalysts employed in the process of the present invention provided the aforementioned parameters are achieved for the resultant catalyst.
One preferred method of making the catalysts of the present invention is comulling or cogelling the desired metals with an appropriate support materials, e.g., silica, alumina, etc., during preparation of the catalyst.
Another preferred method is to separately prepare, the catalyst base or support material followed by impregnation with metals. Acid or base peptization methods can be used.
The percent of macropores in the catalyst can be adjusted using methods known in the art. Percent macropore volume is primarily dependent on two factors: the degree of mixing and the characteristics of the raw materials (such as alumina) used.
The degree of mixing depends on the specific equipment used, the time of mixing and the energy input by the mixer. In general, the percent of macropores can be reduced by increasing the degree of mixing. Conversely, less mixing leads to more macropores. Energy input during catalyst forming (e.g., extrusion) also affects the percent of macropore volume.
The type of raw material affects the percent of macropores produced. This can be illustrated by looking at changes in the dispersion characteristics of alumina (a common catalyst raw material). Aluminas have varying disperεibility indices (DI). The DI test procedure can be found in Kaiser Chemicals' Technical Service Bulletin No. 22. The DI measures the percent of alumina that is disperεed to less than 1 micron size under standard acidic test conditions. Cryεtallized aluminaε, εuch as pεeudo-boehmite, have a wide range of DI valueε (10-100). Thoεe DI are generally higher than gamma-alumina or calcined aluminas (DK10). In order to increase the percent of macropores in a catalyst or catalyst base, a lower DI alumina can be added; in order to decrease the percent of macropores in a catalyst or catalyst base, a higher DI alumina can be added.
Particularly preferred pore, volume in the form of macropores for the catalyst used in the procesε of the present inven- tion is in the range of 7.5 to 10 percent of the total pore volume of the catalyεt. Most preferred macropore volume is about 8 to 9 percent of the total pore volume. Preferred refractory inorganic oxide supportε for the catalyεt used in the present invention include alumina, silica-alumina and silica. Alumina supportε are eεpecially preferred.
The catalyεt used in the process of the present invention desirably contains a hydrogenating component, preferably a Group VI metal and/or a Group VIII metal. Especially pre- ferred Group VI metals are molybdenum and tungsten, and molybdenum is most preferred. Preferred ranges for amounts of Group VI and Group VIII metals are summarized below:
Group VI Group VIII Preferred 0-30 wt% 0-15 wt% More Preferred 1-20 wt% 0.5-10 wt% Moεt Preferred 2-10 wt% 1-4 wt%
Especially preferred Group VIII metals are nickel and cobalt, and nickel is moεt preferred.
he metalε can be incorporated in the catalyst in various manners. One preferred means is impregnation onto the εupport.
The catalyεt can be used in various reactor configurations, but preferably a fixed catalyεt bed is used.
The catalyεt shape and size are chosen so that diffusion limitation and reactor presεure dropε are minimized. Pre- ferably, the catalyεt size is 1/8 to 1/100 inch in diameter, more preferably 1/18 to 1/40 inch in diameter, although the shape of the catalyst may be in various forms, including cylindrical pellets or spheres, or other shapes. Preferred catalystε are noncylindrical, quadrilobe shaped catalyεt such as described in U.S. Patent No. 4,394,303.
The feed to the procesε of the preεent invention preferably is a high boiling hydrocarbonaceous material having a normal boiling range mostly above 600°F.
Thus, the process of the present invention is basically directed to residuum feedstocks as opposed to gas oil feed- stocks. Residua feeds typically have greater than 10 ppm metalε, whereas gas oils nearly always have leεε than 10 ppm metalε, for example, usually only as high as 1 to 4 ppm metals even for heavy vacuum gas oils. Thus, typical feed- stockε for the preεent invention are crude oil atmoεpheric
distillation column bottoms (reduced crude oil or atmo- spheric column residuum), vacuum distillation column bottoms (vacuum residuum) and solvent deasphalted reεidua. Very heavy gaε oilε may have greater than 10 ppm metalε in which case the process of the present invention becomes applicable to gas oil feeds. However, a greater advantage is achieved in application of the present invention to feedstockε having greater than 20 ppm metalε. Thuε, I have found that the process of the present invention is moεt advantageouεly applied to reεiduum feedεtockε which contain moleculeε of very high molecular weight and also greater than about 20 ppm metals. References to metals herein are by weight as the pure or elemental metal. The metals are believed to be present as organometallic compoundε, but the concentration of metalε referred to herein iε calculated aε partε per million pure metal.
The contaminating metalε in the feed typically include nickel, vanadium and iron.
Preferred feedεtockε for the preεent invention preferably contain greater than 0.1% εulfur by weight. The sulfur is present aε organic εulfur compoundε and the wt.% sulfur iε calculated baεed on elemental sulfur.
The proceεε of the preεent invention is carried out at 600 to 1000βF, more preferably, 680 to 800°F. Preferred presεureε are 100 to 10,000 psig, more preferably, 1000 to 3000 psig. Hydrogen to hydrocarbon feed rates are prefer- ably 500 to 20,000, more preferably 2000 to 8000. Liquid hourly εpace velocity (LHSV) to the preferred fixed bed disposition of the catalyst particles is preferably from 0.01 to 10 hr , more preferably from 0.1 to 2 hr .
1 According to other embodiments of the present invention, a 2 catalyεt and catalyεt base are provided in accord with the 3 catalyst described above and having defined macroporosity, 4 defined peak pore diameters and defined mesopore charac- 5 teristics aε deεcribed above. The catalyεt baεe haε εub- 6 stantially the same macroporosity peak pore diameter and 7 mesoporoεity aε the catalyεt described above, but doeε not 8 have Group VI or Group VIII hydrogenation metals. 9 0 DETAILED DESCRIPTION 1 2 The pore size distribution and pore volume are aε εhown in 3 the exampleε. Example 6 provideε a deεcription of mercury 4 porosimetry and data obtained from it. 5 6 The term "macropores" is uεed herein to mean pores with pore 7 diameters >100θA as defined by mercury porosimetry (ASTM 8 D4284). 9 0 The term "mesoporeε" iε uεed herein to mean poreε with pore 1 diameters in the range 35-lOOθA, as defined by mercury 2 porosimetry. Mesopore Volume is determined by mercury 3 porosimetry. 24
25 Average mesopore diameter is calculated for purposeε of with
26 the present invention as follows: 27
■*-.• _. Mesopore Volume (cc/g) .
Λ ΛnΛ D«i__.a»m»e«te«r-. - s«.„u,rf£a.c,
»e
A ,ZreZa" i(Δm
2/
/«gV
) x 40'
000
30 Peak Meεopore Diameter -~ the maximum dV in the range dD
31 35-lOOθA diameter;
32
,, The peak meεopore diameter, aε calculated by mercury poros-
34 imetry depends on the aεεumed mercury contact angle. A contact angle of 140 degrees iε uεed in all calculations
whether for catalyεt baεe or finiεhed (metalε-loaded) catalyεt. Catalyεt baεe componentε εuch aε alumina, εilica, and εilica/alumina have a contact angle of approximately 140 degreeε. The addition of metalε to theεe catalyεt support materials changes the contact angle. Nonetheless, in our calculations for the finished catalystε we assume a contact angle of 140 degrees. In this manner, the peak mesopore diameter for the preferred catalyst supports of this inven- tion were found to be >145A, and the peak meεopore diameter for the preferred catalysts of this invention were found to be >165A, and, if anything, the mesopore diameter would become smaller. Thuε, the greater than 165A diameter may be referred to aε "apparent" diameter.
The term "surface area" is used herein to refer to surface area as measured by nitrogen adsorption using the BET method. Surface areas were determined using the well-known BET method using data from a Micrometricε Inεtrument Corp ASAP 2400, uεing nitrogen.
MCR iε used herein to connote Microcarbon Residue as measured by ASTM D4530-85 test method. According to ASTM D4530-85, MCR is equivalent to Conradεon Carbon.
Vanadium distribution factor iε uεed herein to mean the ratio of the average metal concentration to the concentra- tion at the maximum, typically at the edge of the catalyst particle. Since the distribution factor iε obtained from electron microprobe analyεeε of catalyεt εampleε removed after teεtε are completed, it repreεentε a run average metal
distribution. For εimple firεt-order kineticε, the diεtrib- ution factor is equal to the run average effectiveness fac- tor. For other kinetic orders, the diεtribution factor iε proportional to the run average effectiveness factor, if the maximum concentration occurs at the edge of the catalyst particle.
For most practical applications, the maximum concentration occurs at or near the particle edge. Therefore, a high distribution factor (approaching 1.0) means that the metal- containing species penetrate further into the catalyst and deposit more uniformly in the pores. A low diεtribution factor (approaching 0) meanε the metalε depoεit preferen- tially near the edge of the catalyεt pellet.
EXAMPLES
Example 1 ACID PEPTIZATION OF ALUMINA TO MAKE THE MACROPOROUS CATALYST BASE
865 g of Kaiεer Verεal 250 alumina, an alumina having an acid diεpersibility (DI value) between 20 and 28, was charged to a Baker-Perkins mixer and heated to 130-140°F with good mixing. After five minutes, 873 ml distilled H_0 was added to the mixer slowly over 15 minutes. Then 13.9 g of cone. HN03 (70%) and 42 ml of distilled H20 was added. After eight minutes, 9.9 g of cone. NH4OH (58%) and 30 mL distilled H-O were added over three minutes, while main¬ taining the temperature at about 140°F. After 25 minutes, 859 g of Kaiεer Verεal 150 alumina, an alumina having a DI value between 10-20, waε added into the mixer. Then 704 mL distilled H-O waε added. After about 20 minutes, the mix- ture was cooled to about room temperature. After storing
overnight, the material was extruded in a 2-inch Bonnott extruder using a 0.039-inch die with cooling water on the barrel. The catalyst was extruded and dried immediately at 250°F for two hours and at 400°F for two more hours. Finally, the catalyst base was calcined at 1700°F for one hour with 1 CFH dry air.
The resulting catalyst base had the following properties:
Particle Denεity 0.94 g/cc Skeletal Denεity 3.4 g/cc BET Surface Area 146.8 m2/g
Mercury Poroεimeter Total Pore Volume 0.802 cc/g Macropore Volume 0.0612 cc/g Macroporeε 7.6% Peak Mesopore Diameter 192A Calc. Avg. Mesopore Diameter 202A
Example 2 IMPREGNATION OF THE MACROPOROUS CATALYST BASE
The catalyst base prepared in Example 1 was allowed to rehydrate in air overnight. 150 g of rehydrated base had a total pore volume of 129 cc. The impregnation solution waε prepared by mixing and heating 88.9 g phosphomolybdic acid εolution containing 15.6% Mo and 2.0% P to 40°C. Then, 30% hydrogen peroxide was added a drop at a time until the solution turned a clear, straw yellow color. Distilled water waε added to increaεe the total volume to 97 cc. 7.44 g NiC03 (EM Science, 48.4% Ni) waε added with εtirring at 40°C. After foaming εtopped, the εolution was cooled to 30°C and diluted to 129 cc with distilled water. The base
waε spray porefilled with the εolution. The wet material was allowed to stand overnight, and the resulting catalyst was dried at 250°F for one hour. The dry catalyst waε calcined in a muffle furnace with 20 CFH dry air for εix hours at 200°F, four hours at 450°F, four hours at 750°F, and five hours at 950°F.
The resulting catalyεt has the following properties:
Particle Density 1.11 g/cc Skeletal Density 3.6 g/cc BET Surface Area 130.7 m2/g Mercury TPV 0.6167 Mercury Macro PV 0.0479
Mercury Porosimeter Total Pore Volume 0.802 cc/g Macropore Volume 0.0612 cc/g Macroporeε 7.8% Peak Mesopore Diameter 219A Calc. Avg. Mesopore Diameter 174A
This catalyst is shown on Table II aε Catalyst No. 3.
Example 3 NH4OH PEPTIZATION OF ALUMINA TO MAKE THE MACROPOROUS BASE
785 Grams of Davison SRA alumina waε charged to a large Baker-Perkins mixer. 1800 ml distilled H-O was mixed (146 cc) NH4OH (58%) so that the resulting solution pH was 10.5. 1500 g of this solution waε added into the mixer at 200 ml/min while mixing. After all the εolution waε added, the mixture waε mixed for 10 more minuteε. Then 785 g of Kaiεer
Verεal 250 alumina was added into the mixture and mixed for another 50 minutes. Half the product was extruded in a 2-inch Bonnott extruder using a 0.039-inch die, with cooling. The extrudateε were dried and broken into pieceε of L/D of 2-3 and then put into a preheated Freaε oven at 250°F for 2 hours. Then the temperature waε raiεed to 400°F for 2 more hours. Finally, the catalyst baεe was calcined at 1700°F for 1 hour in 1 CFH dry air. The properties of the resulting catalyst base are shown below.
Particle Density 0.87 g/cc Skeletal Denεity 3.4 g/cc BET Surface Area 142 m /g
Mercury Poroεimeter Total Pore Volume 0.855 cc/g Macropore Volume 0.077 cc/g Macroporeε 9.0% Peak Mesopore Diameter 184A Calc. Avg. Mesopore Diameter 219A
Example 4 IMPREGNATION OF THE MACROPOROUS CATALYST BASE
The base of Example 3 was impregnated in a manner similar to the method of Example 2. The properties of the resulting catalyεt are εhown below:
Particle Denεity 1.053 g/cc Skeletal Density 3.706 g/cc BET Surface Area 130 m2/g
Mercury Poroεimeter Total Pore Volume 0.680 cc/g Macropore Volume 0.0621 cc/g Macroporeε 9.1% Peak Meεopore Diameter 215A Calc. Avg. Meεopore Diameter 190A
This catalyst is εhown on Table II as Catalyst
Example 5 CATALYST SUPPORT PREPARATION
865 Pounds Versal 250 alumina (DI « 24) and 96 lbε micronized calcined alumina fineε were mixed in a Littleford mixer with 17.5 lbε nitric acid in 650 lbε water over about 20 minutes. Mixing was continued for 15 minutes after all the liquid was added. Then 6 lbs of aqueouε ammonia and 174 lbε water and then mixed for 5 minuteε. Thiε material waε extruded in a 6-inch Bonnot extruder. Extruεion required about 1 hour. The extrudate waε dried on a Proctor-Schwarz belt dryer at 200°C for about 15 minuteε and then calcined in εtationary air at 900°C for 1 hour.
The resulting catalyst baεe had the following propertieε:
Particle Density 0.89 g/cc Skeletal Density 3.44 g/cc BET Surface Area 137 m2/g
Mercury Porosimeter Total Pore Volume 0.788 cc/g Macropore Volume 0.0544 cc/g Macroporeε 6.9%
Peak Mesopore Diameter 184A Calc. Avg. Mesopore Diameter 214A
Example 6 PORE SIZE DISTRIBUTION BY MERCURY POROSIMETRY
The method used to determine the pore size diεtribution of catalysts, over the range of 35A to 20,OOθA microns is pore size diεtribution by mercury poroεimetry.
The method iε outlined below. It iε related to ASTM D4284, "Pore Volume Diεtribution of Catalysts by Mercury Intrusion Porosimetry". A catalyst iε heated at 450°C in a vacuum for 30 minuteε to remove water vapor and other volatileε. A weighed portion of sample (0.3-0.5 g, depending on the total pore volume estimate) is placed in the volume-calibrated sample tube. The tube is filled with mercury and inserted into the pressurization chamber of a Quantachrome Auto-Scan Porosimeter. The preεεure in the chamber is increased from o to 60,000 psig. As the pressure increaseε, the volume of mercury in the sample tube appears to decrease as the mercury intrudes into the pores of the sample. Apparent mercury volume iε obtained aε a function of the applied preεεure. Apparent mercury volume and applied pressure are then related to pore volume (V) and pore diameter (D), respectively. Resultε are reported as plots of pore volume (cc) and cumulative pore volume (cc) as functions of diameter (A). Numeric pore size distribution information is also reported. Data obtained from analysis includes:
Total Pore Volume; Mesopore Volume (volume in pores with 35-lOOθA diameter); Macropore Volume (volume in pores with >100θA diameter);
1 „% M„acropore „Vol. ~- Macropore V—olu Tot.al Por—e Vo -,me ,««» 2 ume _ lume x 100%;' 3 Peak Meεopore Diameter ~~ the maximum dV in the range dD 4 35-lOOθA diameter; and 5 the differential pore volume verεuε diameter (dV vε. D). 6 dD 7 8 9 A contact angle of 140° is asεumed for all calculationε. 0 The χ (diameter) axis of the plot will be offset from the 2 true values if the εample haε any other contact angle 2 with Hg. A contact angle of 140° iε good for aluminum, 3 silica or silica/alumina* materials. However, when metalε are added (εuch aε by impregnation and calcination), the 5 apparent mesopore peak diameter increaseε by approximately g 20A because the actual contact angle deviates from 140°. 7 8 Example 7 9 CATALYST SCREENING TEST 0 i Catalyεtε were teεted using 120 cc of catalyst in a 1-inch 2 ID upflow packed bed reactor in a hydroproceεεing pilot 3 plant. 4 5 The teεt conditions were: 6 7 2000 psig Total Pressure 8 0.75 LHSV g 5000 SCF/Bbl Hydrogen Once-Through Gaε 0 713°F Catalyεt Temperature (0-250 Hours) 2 755°F Catalyst Temperature (250-700 Hours) 2 3 The feed was a residuum obtained from a blend of 23% Arabian 4 Heavy crude and 77% Maya crude.
The feed properties (650°F+ Reεid) were aε followε:
API Gravity 9.8 Sulfur, wt% 4.4 Nitrogen, wt% 0.5 Nickel, ppm 66 Vanadium, ppm 350 MCR, wt% 16.8 Viscosity at 100°C, cSt 280 D1160 650°F-, 2.2 650-850°F 23.9 850-1000°F 19.4 1000βF+ 54.4 D1160 50 LV% 1035βF VTGA 1000°F+, wt% 58.5
At 700 hours, the demetalated and deεulfurized product was analyzed to determine percent vanadium, εulfur and MCR conversion. The catalyst waε examined to determine vanadium distribution factor.
Catalysts in accord with the preεent invention have been found to give the following results under the above test conditions: V diεtribution factor >0.45 V conversion >75% S conversion >65% MCR conversion >38%
Example 8 t COMPARISON CATALYST
This example compares a catalyst in accordance with Taiwanese Patent No. NI-23,976 to a catalyst in accordance
-19-
with the preεent invention uεed in a hydrodemetalation/hy- drodesulfurization application. Key properties of the catalyst and the resulting εulfur removal, MCR removal and vanadium removal, after 700 hours onstream, are given in Table I below.
TABLE I
% Macropore Volume
Average Meεopore Dia. , A 110 190
% Converεion at 700 Hours
Sulfur 74 68
MCR 41 40
Vanadium 67 76
Vanadium Distribution Factor 0.39 0.55
The high vanadium removal and the high vanadium distribution factor show the improved demetalation achieved with the catalystε prepared according to the preεent invention compared with other catalyεtε. Thiε catalyst is shown on Table II aε Catalyεt No. 10.
Example 9 PREPARATION OF CATALYSTS NO. 1, 2, 5, 6, 1 , 8, 9
other catalystε were prepared in a manner εimilar to Exampleε 1 and 2, or 3 and 4. The percent of macroporeε waε adjuεted by varying the typeε of aluminas, their DI values and the reaction conditions as described earlier. In this manner catalystε No. 2 and 5 of the invention were prepared. Alεo in this manner, comparative Catalystε No. 1, 6, 7, 8 and 9 were prepared.
Table II, below, summarizes the catalyst properties and test resultε. As can be seen in the Table, the catalysts of the present invention, Catalyεtε 2-5, have good vanadium converεionε (>74% after 700 hourε), and good vanadium diεtributions; these catalystε alεo have good εulfur converεionε, >65% after 700 hours.
in general, catalysts with fewer macropores (Catalyεt 1) give low vanadium converεion and low vanadium diεtribution factorε, while catalystε with a greater percentage of macroporeε (catalyεtε 6-10) than the catalyεtε of thiε invention generally have lower εulfur converεions.
TABLE II
CATALYST PROPERTIES AND TEST RESULTS (1)
BET
Catalyst
1 Low Macropore Cat.
2 Cat. in accord with invention,
HNO Peptization
3 Cat. in accord with invention, 7.8 219 174 130 69.3 41.0 75.6 0.47 HNO Peptization, EX. 2
4 Cat. in accord with invention, 9.1 215 190 130 68.4 39.6 76.3 0.55 NH.OH Peptization, Ex. 4
5 Cat. in accord with invention, 10.6 208 209 124 65.7 39.1 79.8 (2) t*o HNO, Peptization
13% Macropore Cat. 12.7 189 170 36.7 78.3 0.52 14% Macropore Cat. 13.7 165 170 38.3 73.8 0.39 14% Macropore cat. 13.8 185 189 36.7 76.7 0.52 High Macropore Cat. 25.4 161 148
32.9 76.6 0.53
10 Taiwanese Patent NI 23-976, Ex. 8 25.3 107 110 186 73.7 41.3 66.9 0.39
(1) Catalysts 2-5 are catalysts of the invention.
(2) Noncylindrical catalyst - V distribution factor could not be measured; very high V conversion shows that catalyst had good V distribution. top TGD:ivb-c_n/PAT76