CA1159402A - Segregating used catalyst fractions by liquid fluidization - Google Patents
Segregating used catalyst fractions by liquid fluidizationInfo
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- CA1159402A CA1159402A CA000338243A CA338243A CA1159402A CA 1159402 A CA1159402 A CA 1159402A CA 000338243 A CA000338243 A CA 000338243A CA 338243 A CA338243 A CA 338243A CA 1159402 A CA1159402 A CA 1159402A
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Abstract
SEGREGATING USED CATALYST FRACTIONS
BY LIQUID FLUIDIZATION
ABSTRACT OF THE DISCLOSURE
Used catalysts contaminated with various metals contents during processing of hydrocarbon feedstocks can be effectively segregated by density difference using fluidization with a light liquid having selected specific gravity range. The lighter weight less contaminated catalyst portion which rises is returned to the reaction zone for further use, while the heavier more contaminated catalyst portion which drops is usually discarded. Such segregation recovery and reuse of still active catalyst particles from a reaction process significantly reduces the overall catalyst consumption and costs for various catalytic reaction processes. This catalyst segregation and reclaiming procedure is particularly useful for recovering used catalyst from fluidized catalyst be systems, e.g. H-Oil? and H-Coal? hydrogenation processes using ?bullated bed reactors, from fluid catalytic cracking (FCC) processes, and also from fixed catalytic bed reaction systems.
BY LIQUID FLUIDIZATION
ABSTRACT OF THE DISCLOSURE
Used catalysts contaminated with various metals contents during processing of hydrocarbon feedstocks can be effectively segregated by density difference using fluidization with a light liquid having selected specific gravity range. The lighter weight less contaminated catalyst portion which rises is returned to the reaction zone for further use, while the heavier more contaminated catalyst portion which drops is usually discarded. Such segregation recovery and reuse of still active catalyst particles from a reaction process significantly reduces the overall catalyst consumption and costs for various catalytic reaction processes. This catalyst segregation and reclaiming procedure is particularly useful for recovering used catalyst from fluidized catalyst be systems, e.g. H-Oil? and H-Coal? hydrogenation processes using ?bullated bed reactors, from fluid catalytic cracking (FCC) processes, and also from fixed catalytic bed reaction systems.
Description
1 159~U2 ACKGROUND OF THE INVENTION
This invention ~ertains to the recovery of used contamin-ated catalyst according to particle density differences, and particularly to segregating and recovering such catalysts by fluidization in light liquids.
Catalytic reaction processes usually involve deactivation of the catalyst by various metallic elements being deposited thereon from the feedstock and develop a situation in which different particles of the catalyst contain widely different amounts of the deactivating element or elements. This situa-tion develops in two basically different kinds of catalytic reaction systems, namely, fluidized catalyst bed systems and fixed catalyst bed systems. In fluidized catalyst bed systems, such as for H-Oil ~, H-Coal ~ and fluid catalytic cracking processes which involve continuous or periodic withdrawal of portions of used catalyst and their replacement with fresh catalyst, the catalyst bed in the reactor contains particles that have been in the reactor for widely different periods of time. Those particles that have been in the reactor for only a short time have a relatively low metals content and still possess relatively high catalytic activity, but all are dis-carded proportionately in the catalyst withdrawals. This re-sults in substantial and undesirable catalyst replacement quan-tities and expense.
In fixed bed catalyst systems, such as some petroleum de-metallization systems, where the metallic agent tends to deposit towards the inlet end of the bed, the outlet end catalyst par-ticles are relatively free of contaminants. During catalyst replacement at unit turnarounds, it is possible to segregate the catalyst from the various sections of the fixed bed and l 159~2 reuse the less contaminated portions. But this is an involved task, and it is difficult to clearly identify the less contam-inated reusable portions of the catalyst in a practical manner.
Thexe has been a lack of a practical method for segregat-ing reusable catalyst. The development of a catalyst segrega-tion method which would result in reduced catalyst usage and costs for partic~llar reaction processes which cause catalyst contamination is clearly needed. The present invention pro-vides an advantageous method for segregating and reclaiming more active used catalyst particles by density difference utilizing liquid fluidization.
SUMMARY OF THE INVENTION
-This invention provides a method for segregating used con-taminated catalyst particles having variable metals contaminant contents and density, so that the portion of used catalyst material having relatively low contaminant content can be readily recovered for further use at a satisfactory level of activity. Specifically, it has been found that the variation in the particle density of used catalyst can be used to separ-ate a less contaminated more active catalyst portion from amore contaminated less active catalyst portion according to density by using fluidization in a light liquid. By placing the used catalyst in a column of the upflowing light liquid, such as a hydrocarbon process fraction, for example, naphtha, kerosene or fuel oil, or water, under conditions producing gentle agitation of the catalyst, substantial vertical segre-gation of the catalyst particles is produced. The column length/diameter ratio should be at least about 4/1 and usually need not exceed about 50/1. Under conditions of gentle to moderate agitation the less contaminated lower density catalyst ~ 1~9~32 particles will gradually migrate upward, while the heavier more contaminated catalyst will gradually settle downward towards the bottom of the column as a result of the fluidizing force of the upflowing liquid and gravity force. The catalyst bed should be expanded by at least about 20~ of its settled height and suf-ficient to achieve adequate segregation of the catalyst. The fluidizing time should be at least 5 minutes to accomplish a significant degree of catalyst segregation. The catalyst par-ticle size may range from about 2 to about 200 mesh US Sieve Series.
After substantially all catalyst particle migration has occurred, the upper less contaminated portion of the segregated catalyst is removed for reuse in the reaction process, prefer-ably after regeneration by carbon burnoff, thus reducing the amount of fresh make-up catalyst required. The lower more con-taminated and denser portion of catalyst is removed and is either processed for metals recovery using known procedures or is discarded.
The specific gravity and upward velocity of the flota-tion liquid used to separate the catalyst particles should beselected so as to provide the catalyst bed expansion and segre-gation desired. The distribution of catalyst particles within the expanded bed will depend upon several factors, such as catalyst density, the liquid density or specific gravity, and the percent bed expansion used.
The present invention will now be described in more detail, with-reference to the accompanying drawings, which illustrate by way of example only the invention, and in which:
FIGURE 1 is a process flow diagram showing catalyst re-moval from a reaction process, followed by catalyst segregationand regeneration steps; and i 1594~
FIGURE 2 is a graph showing the results of a catalyst ac-tivity test for various samples of used catalyst compared to fresh catalyst.
DESCRIPTIONS OF PREFERRE~ EMBODIMENTS
-As shown in Figure 1, used catalyst particles, partially contaiminated with deposited metal impurities such as nickel and vanadium, are removed from a fluidized or fixed bed reac-tion process 10 and introduced into fluidization unit 12. This unit is supplied through conduit 14 with a liquid having speci-fic gravity within a range of 0.65-1.2. The liquid is circu-lated uniformly upwardly through a generally vertical tube or column 16 by pump 18 and distributor 15 at a velocity sufficient to expand the catalyst bed by at least about 20% of its set-tled height, so as to produce a fluidization and segregation of the catalyst particles according to their density. The catalyst will be segregated into light weight less contamin-ated particles 16a in the upper portion of column 16 and heavier more contaminated particles 16b in the lower portion of the column. The preferred catalyst bed expansion is 30-200%
of settled height. After such catalyst segregation has occur-red, usually within 0.1 to 20 hours depending upon the catalyst density range, the degree of catalyst bed expansion, etc., the particles 16a in the upper portion of the column 16 are removed at 20 and can be regenerated at 22 to remove carbon deposits, and then returned via line 23 to reaction process 10 for reuse.
The particles 16b in the lower portion are removed at 24, and can be processed at 26 ~o recover the deposited metals, or dis-carded as desired. Make-up fluidizing liquid is added at 17 as needed, and contaminated liquid is removed at 19, preferably for return to the reaction process 10.
~594~
Suitable fluidizing liquids are ]ight hydrocarbon frac-tions having a boiling range of 200 to 450F, such as light naphtha, kerosene or fuel oil, or water, with a light process naphtha fraction being the preferred fluidizing liquid. The upward liquid superficial velocity used will depend upon the density and size of the catalyst particles and the viscosity and density of the liquid, but Should usually be at least .04 ft/sec and preferably within the range of .06 to 0.20 ft/sec.
Static pressure in column 16 is usually 0-50 psig and tempera-ture is 50F to 300F. The length to diameter ratio of the column 16 should be at least about 4 and usually need not ex-ceed about 50, with the ratio preferably being between 5 and 40.
It has been found that the catalyst fines contain an in-creased concentration of metals as compared to the larger cat-alyst particles~ It has thus been found advantageous to screen the used catalyst to remove the fine portion before reusing the remaining portion of catalyst. Also as another embodiment of the invention, the column of fluidized catalyst in liquid can be made to have variable cross-sectional area.
The invention will be further illustrated by reference to the following examples of catalyst segregation by fluidization using a light liquid.
Example l A quantity of l/32" diameter extrudate catalyst removed from an ebullated bed reactor hydroprocessing a Middle East crude oil was washed in solvent to remove the oil-coating. The oil-free catalyst was placed in an 0.76 dia. x 30-inch long glass tube to height of twelve (12) inches of catalyst and fluidized in water to lO0 percent bed expansion, which required a linear velocity of 0.11 ft/sec. Fluidization continued for l 1~9~02 16 hours. The catalyst was then allowed to settle and was dried in situ at 450F with nitrogen gas flowing downward.
The tube was then positioned horizontally and, by means of a ladle, 10 approximately equal volume fractions were removed.
Each fraction was then analyzed for vanadium and nickel which are contaminants laid down during the hydroprocessing, and ~or molybdenum which is contained in the origlnal catalyst. The results are presented in Table 1. The fines portions (minus 20 mesh) from fractions 1, 5 and 10 were screened out and analyzed separately; these results are also presented in Table 1.
Table 1 ANALYSIS OF USED H-OIL CATALYST SEGREGATED BY
FLUIDIZATION WITH WATER
W %
Fraction _ V Ni Mo 1 Top 6.4 5.120.37 5.17 1(-20 mesh) 10.5 1.24 4.75
This invention ~ertains to the recovery of used contamin-ated catalyst according to particle density differences, and particularly to segregating and recovering such catalysts by fluidization in light liquids.
Catalytic reaction processes usually involve deactivation of the catalyst by various metallic elements being deposited thereon from the feedstock and develop a situation in which different particles of the catalyst contain widely different amounts of the deactivating element or elements. This situa-tion develops in two basically different kinds of catalytic reaction systems, namely, fluidized catalyst bed systems and fixed catalyst bed systems. In fluidized catalyst bed systems, such as for H-Oil ~, H-Coal ~ and fluid catalytic cracking processes which involve continuous or periodic withdrawal of portions of used catalyst and their replacement with fresh catalyst, the catalyst bed in the reactor contains particles that have been in the reactor for widely different periods of time. Those particles that have been in the reactor for only a short time have a relatively low metals content and still possess relatively high catalytic activity, but all are dis-carded proportionately in the catalyst withdrawals. This re-sults in substantial and undesirable catalyst replacement quan-tities and expense.
In fixed bed catalyst systems, such as some petroleum de-metallization systems, where the metallic agent tends to deposit towards the inlet end of the bed, the outlet end catalyst par-ticles are relatively free of contaminants. During catalyst replacement at unit turnarounds, it is possible to segregate the catalyst from the various sections of the fixed bed and l 159~2 reuse the less contaminated portions. But this is an involved task, and it is difficult to clearly identify the less contam-inated reusable portions of the catalyst in a practical manner.
Thexe has been a lack of a practical method for segregat-ing reusable catalyst. The development of a catalyst segrega-tion method which would result in reduced catalyst usage and costs for partic~llar reaction processes which cause catalyst contamination is clearly needed. The present invention pro-vides an advantageous method for segregating and reclaiming more active used catalyst particles by density difference utilizing liquid fluidization.
SUMMARY OF THE INVENTION
-This invention provides a method for segregating used con-taminated catalyst particles having variable metals contaminant contents and density, so that the portion of used catalyst material having relatively low contaminant content can be readily recovered for further use at a satisfactory level of activity. Specifically, it has been found that the variation in the particle density of used catalyst can be used to separ-ate a less contaminated more active catalyst portion from amore contaminated less active catalyst portion according to density by using fluidization in a light liquid. By placing the used catalyst in a column of the upflowing light liquid, such as a hydrocarbon process fraction, for example, naphtha, kerosene or fuel oil, or water, under conditions producing gentle agitation of the catalyst, substantial vertical segre-gation of the catalyst particles is produced. The column length/diameter ratio should be at least about 4/1 and usually need not exceed about 50/1. Under conditions of gentle to moderate agitation the less contaminated lower density catalyst ~ 1~9~32 particles will gradually migrate upward, while the heavier more contaminated catalyst will gradually settle downward towards the bottom of the column as a result of the fluidizing force of the upflowing liquid and gravity force. The catalyst bed should be expanded by at least about 20~ of its settled height and suf-ficient to achieve adequate segregation of the catalyst. The fluidizing time should be at least 5 minutes to accomplish a significant degree of catalyst segregation. The catalyst par-ticle size may range from about 2 to about 200 mesh US Sieve Series.
After substantially all catalyst particle migration has occurred, the upper less contaminated portion of the segregated catalyst is removed for reuse in the reaction process, prefer-ably after regeneration by carbon burnoff, thus reducing the amount of fresh make-up catalyst required. The lower more con-taminated and denser portion of catalyst is removed and is either processed for metals recovery using known procedures or is discarded.
The specific gravity and upward velocity of the flota-tion liquid used to separate the catalyst particles should beselected so as to provide the catalyst bed expansion and segre-gation desired. The distribution of catalyst particles within the expanded bed will depend upon several factors, such as catalyst density, the liquid density or specific gravity, and the percent bed expansion used.
The present invention will now be described in more detail, with-reference to the accompanying drawings, which illustrate by way of example only the invention, and in which:
FIGURE 1 is a process flow diagram showing catalyst re-moval from a reaction process, followed by catalyst segregationand regeneration steps; and i 1594~
FIGURE 2 is a graph showing the results of a catalyst ac-tivity test for various samples of used catalyst compared to fresh catalyst.
DESCRIPTIONS OF PREFERRE~ EMBODIMENTS
-As shown in Figure 1, used catalyst particles, partially contaiminated with deposited metal impurities such as nickel and vanadium, are removed from a fluidized or fixed bed reac-tion process 10 and introduced into fluidization unit 12. This unit is supplied through conduit 14 with a liquid having speci-fic gravity within a range of 0.65-1.2. The liquid is circu-lated uniformly upwardly through a generally vertical tube or column 16 by pump 18 and distributor 15 at a velocity sufficient to expand the catalyst bed by at least about 20% of its set-tled height, so as to produce a fluidization and segregation of the catalyst particles according to their density. The catalyst will be segregated into light weight less contamin-ated particles 16a in the upper portion of column 16 and heavier more contaminated particles 16b in the lower portion of the column. The preferred catalyst bed expansion is 30-200%
of settled height. After such catalyst segregation has occur-red, usually within 0.1 to 20 hours depending upon the catalyst density range, the degree of catalyst bed expansion, etc., the particles 16a in the upper portion of the column 16 are removed at 20 and can be regenerated at 22 to remove carbon deposits, and then returned via line 23 to reaction process 10 for reuse.
The particles 16b in the lower portion are removed at 24, and can be processed at 26 ~o recover the deposited metals, or dis-carded as desired. Make-up fluidizing liquid is added at 17 as needed, and contaminated liquid is removed at 19, preferably for return to the reaction process 10.
~594~
Suitable fluidizing liquids are ]ight hydrocarbon frac-tions having a boiling range of 200 to 450F, such as light naphtha, kerosene or fuel oil, or water, with a light process naphtha fraction being the preferred fluidizing liquid. The upward liquid superficial velocity used will depend upon the density and size of the catalyst particles and the viscosity and density of the liquid, but Should usually be at least .04 ft/sec and preferably within the range of .06 to 0.20 ft/sec.
Static pressure in column 16 is usually 0-50 psig and tempera-ture is 50F to 300F. The length to diameter ratio of the column 16 should be at least about 4 and usually need not ex-ceed about 50, with the ratio preferably being between 5 and 40.
It has been found that the catalyst fines contain an in-creased concentration of metals as compared to the larger cat-alyst particles~ It has thus been found advantageous to screen the used catalyst to remove the fine portion before reusing the remaining portion of catalyst. Also as another embodiment of the invention, the column of fluidized catalyst in liquid can be made to have variable cross-sectional area.
The invention will be further illustrated by reference to the following examples of catalyst segregation by fluidization using a light liquid.
Example l A quantity of l/32" diameter extrudate catalyst removed from an ebullated bed reactor hydroprocessing a Middle East crude oil was washed in solvent to remove the oil-coating. The oil-free catalyst was placed in an 0.76 dia. x 30-inch long glass tube to height of twelve (12) inches of catalyst and fluidized in water to lO0 percent bed expansion, which required a linear velocity of 0.11 ft/sec. Fluidization continued for l 1~9~02 16 hours. The catalyst was then allowed to settle and was dried in situ at 450F with nitrogen gas flowing downward.
The tube was then positioned horizontally and, by means of a ladle, 10 approximately equal volume fractions were removed.
Each fraction was then analyzed for vanadium and nickel which are contaminants laid down during the hydroprocessing, and ~or molybdenum which is contained in the origlnal catalyst. The results are presented in Table 1. The fines portions (minus 20 mesh) from fractions 1, 5 and 10 were screened out and analyzed separately; these results are also presented in Table 1.
Table 1 ANALYSIS OF USED H-OIL CATALYST SEGREGATED BY
FLUIDIZATION WITH WATER
W %
Fraction _ V Ni Mo 1 Top 6.4 5.120.37 5.17 1(-20 mesh) 10.5 1.24 4.75
2 8.7 7.330.64 5.20
3 8.9 8.440.85 4.97
4 9.4 8.870.93 5.17 9.4 9.901.06 5.00
5(-20 mesh) 16.0 2.03 4.34
6 11.0 11.31.36 4.93
7 10.7 11.61.41 4.90
8 9.8 12.41.52 4.70
9 12.4 14.61.78 4.62 13.3 14.21.86 4.38
10(-20 mesh) 18.1 2.70 3.72 ~ 1 5 ~ 2 The minus 20 mesh fines portion conta:ined much higher contamin-ating metals loading than the plus 20 mesh particles, and were not evenly distributed throughout the segregated catalyst bed.
Top fraction 1 contained 16 W % fines, middle fraction 5 had 8 W % and bottom fraction 10 had 4 W % fines. Screening out -the minus 20 mesh fraction from used catalyst removes the least active portion of used catalyst removed from a hydrogenation reactor.
Example 2 A quantity of lt32" extrudate catalyst contaminated with metals deposited thereon from a petroleum hydrogenation pro-cess was placed as received in a vertical galss tube 0.76 inch diameter by 30 inches long to a height of 12 inches. The used catalyst was fluidized using upflowing No. 2 fuel oil for 6 hours. The liquid upward flow rate was 0.08 ft/sec., which resulted in 50-70% expansion of the catalyst bed. Fluidiza-tion was then stopped and the catalyst bed allowed to settle, the oil was drained and the catalyst washed in situ by passing toluene downward through it. After drying the catalyst using N2 gas at about 450F, four approximately equal volume frac-tions of catalyst were removed from the tube and analyzed.
Results of the analyses are given in Table 2. It is seen that catalyst segregation was achieved, in that the topmost fraction of catalyst contained about half as much meatl con-taminants (nickel plus vanadium) per unit of catalyst (moly-bdenum) as the bottom fraction, indicating that substantial segregation of the catalyst particles had occurred according to the metals loading on the catalyst.
~ ~ 5~4~
ANALYSIS OF USED CATALYST SEGREGATED BY
FLUIDIZATION WITH NO. 2 FUEL OIL
W %
Fraction W ~ V _ Ni Mo 1 T~p 25.9 7.40 1.28 5.50 2 22.5 8.93 1.59 5.46 3 26.1 10.07 1.82 4.94 4 ~ottom25.5 11.97 2.18 4.45 Example 3 Standard activity tests were run on an untreated catalyst removed from a hydroprocessing operation, and a segregated light catalyst fraction, both with and without regeneration, for comparison with fresh catalyst. Oil-free catalyst samples were prepared by extracting as received used catalyst with toluene to remove process oil and drying for 16 hours in air at 220F. A segregated catalyst sample was prepared by fluid-izing for 6 hours in No. 2 fuel oil as for Example 2. The fluidizing oil was washed off using toluene percolated down-ward through the glass tube, and dried in situ at 450F withdownward flowing nitrogen. The top 42 W ~ of plus 20 mesh catalyst was used for an activity test evaluating the rate of desulfurization of a petroleum residuum.
A regenerated catalyst sample was prepared by heating used oil-free catalyst in a 1 inch diameter by 30-inch "Vycor"* heat resistant glass tube positioned vertically in an electrically heated tube furnace held at 850F. A gas containing 2 volume %
oxygen and 98 volume ~ nitrogen was introduced from the top *Trademark for a glass comprising approximately 96% silica.
It has exceptional chemical stability, high softening point, and a very low expansion coefficient. For a further descrip-tion, see "The Condensed Chemical Dictionary", 6th Edition (1961), Reinhold Publishing Corp.
_g_ ~ ~ 5g~2 flowing at 5.8 SCFH. Heating continued for 12 hours.
A segregated plus regenerated catalyst sample was pre-pared by fluidizing in No. 2 fuel oil as previously described, taking approximately the top 45 W ~ fraction, screening out the ~inus 20 mesh fines portion and regenerating it in a "Vycor"TM heat resistant glass as previously described.
The fresh catalyst was the same cobalt-molybdenum 1/32"
diameter extrudates used in a H-Oil ~ ebullated bed reactor processing a Middle East crude oil. Table 3 presents the analyses obtained on the above catalysts samples prepared for the activity tests.
Catalyst evaluation was made using short term desulfuri-zation activity tests performed for four days duration on the four prepared catalyst samples in a standard upflow fixed bed hydrogenation unit. The runs were made on Kuwait vacuum bot-toms feed at 825F temperature, space velocity of 2 volumes of oil per volume of catalyst, 1100 psig hydrogen pressure, and 6000 SCF hydrogen per barrel throughput. In order to~compare the results, the experimental data were converted to a desul-furization rate constant. The calculated data on fresh and used catalysts are presented in Figure 2 as a function of time on stream. It is seen that the segregated plus regenerated catalyst (line 2) showed the most improvement in desulfuriza-tion activity over the untreated catalyst (line 5). Comparing the slopes of the deactivation curves, this catalyst also showed a lower rate of catalyst deactivation as compared to the regenerated only catalyst (line 3) or the fresh catalyst (line 1). The segregated only catalyst sample was better than the used as received washed catalyst.
Although we have disclosed certain preferred embodiments of our invention, it is recognized that modifications may be 1 ~ ~9llO2 made thereto within the spirt and scope of the disclosure and as defined solely by the following claims.
ANALYSIS OF CATALYSTS BY
RESIDUUM DESULFURIZATION ACTIVITY TESTS
Used Fresh Used Used Used Segregated &
Catalvst As Received Segregated Regenerated Regenerated Vanadium, W % 10.40 7.67 13.25 10.05 Nickel, W % 1.70 1.29 1.94 1.52 Molybdenum, W % 4.97 5.55 5.59 6.90 rarbon~ W % 19.03 24.24 0.10 0.14 Sulfur, W % 12.0 9.42 5.69 5.76 C.B.D.**, g/cm3 0.590 1.169 1.127 0.902 0.850 Pore Volume cm jg0.690 0.293* 0.255* 0.447* 0.589*
Surface Area, m2/g 288 57* 30* 106* 164*
Particle Dens., g/cm3 3.202 2.561 2.561 3.068 3.254 *Corrected to Fresh Catalyst Basis **Ccmpared Bulk Density
Top fraction 1 contained 16 W % fines, middle fraction 5 had 8 W % and bottom fraction 10 had 4 W % fines. Screening out -the minus 20 mesh fraction from used catalyst removes the least active portion of used catalyst removed from a hydrogenation reactor.
Example 2 A quantity of lt32" extrudate catalyst contaminated with metals deposited thereon from a petroleum hydrogenation pro-cess was placed as received in a vertical galss tube 0.76 inch diameter by 30 inches long to a height of 12 inches. The used catalyst was fluidized using upflowing No. 2 fuel oil for 6 hours. The liquid upward flow rate was 0.08 ft/sec., which resulted in 50-70% expansion of the catalyst bed. Fluidiza-tion was then stopped and the catalyst bed allowed to settle, the oil was drained and the catalyst washed in situ by passing toluene downward through it. After drying the catalyst using N2 gas at about 450F, four approximately equal volume frac-tions of catalyst were removed from the tube and analyzed.
Results of the analyses are given in Table 2. It is seen that catalyst segregation was achieved, in that the topmost fraction of catalyst contained about half as much meatl con-taminants (nickel plus vanadium) per unit of catalyst (moly-bdenum) as the bottom fraction, indicating that substantial segregation of the catalyst particles had occurred according to the metals loading on the catalyst.
~ ~ 5~4~
ANALYSIS OF USED CATALYST SEGREGATED BY
FLUIDIZATION WITH NO. 2 FUEL OIL
W %
Fraction W ~ V _ Ni Mo 1 T~p 25.9 7.40 1.28 5.50 2 22.5 8.93 1.59 5.46 3 26.1 10.07 1.82 4.94 4 ~ottom25.5 11.97 2.18 4.45 Example 3 Standard activity tests were run on an untreated catalyst removed from a hydroprocessing operation, and a segregated light catalyst fraction, both with and without regeneration, for comparison with fresh catalyst. Oil-free catalyst samples were prepared by extracting as received used catalyst with toluene to remove process oil and drying for 16 hours in air at 220F. A segregated catalyst sample was prepared by fluid-izing for 6 hours in No. 2 fuel oil as for Example 2. The fluidizing oil was washed off using toluene percolated down-ward through the glass tube, and dried in situ at 450F withdownward flowing nitrogen. The top 42 W ~ of plus 20 mesh catalyst was used for an activity test evaluating the rate of desulfurization of a petroleum residuum.
A regenerated catalyst sample was prepared by heating used oil-free catalyst in a 1 inch diameter by 30-inch "Vycor"* heat resistant glass tube positioned vertically in an electrically heated tube furnace held at 850F. A gas containing 2 volume %
oxygen and 98 volume ~ nitrogen was introduced from the top *Trademark for a glass comprising approximately 96% silica.
It has exceptional chemical stability, high softening point, and a very low expansion coefficient. For a further descrip-tion, see "The Condensed Chemical Dictionary", 6th Edition (1961), Reinhold Publishing Corp.
_g_ ~ ~ 5g~2 flowing at 5.8 SCFH. Heating continued for 12 hours.
A segregated plus regenerated catalyst sample was pre-pared by fluidizing in No. 2 fuel oil as previously described, taking approximately the top 45 W ~ fraction, screening out the ~inus 20 mesh fines portion and regenerating it in a "Vycor"TM heat resistant glass as previously described.
The fresh catalyst was the same cobalt-molybdenum 1/32"
diameter extrudates used in a H-Oil ~ ebullated bed reactor processing a Middle East crude oil. Table 3 presents the analyses obtained on the above catalysts samples prepared for the activity tests.
Catalyst evaluation was made using short term desulfuri-zation activity tests performed for four days duration on the four prepared catalyst samples in a standard upflow fixed bed hydrogenation unit. The runs were made on Kuwait vacuum bot-toms feed at 825F temperature, space velocity of 2 volumes of oil per volume of catalyst, 1100 psig hydrogen pressure, and 6000 SCF hydrogen per barrel throughput. In order to~compare the results, the experimental data were converted to a desul-furization rate constant. The calculated data on fresh and used catalysts are presented in Figure 2 as a function of time on stream. It is seen that the segregated plus regenerated catalyst (line 2) showed the most improvement in desulfuriza-tion activity over the untreated catalyst (line 5). Comparing the slopes of the deactivation curves, this catalyst also showed a lower rate of catalyst deactivation as compared to the regenerated only catalyst (line 3) or the fresh catalyst (line 1). The segregated only catalyst sample was better than the used as received washed catalyst.
Although we have disclosed certain preferred embodiments of our invention, it is recognized that modifications may be 1 ~ ~9llO2 made thereto within the spirt and scope of the disclosure and as defined solely by the following claims.
ANALYSIS OF CATALYSTS BY
RESIDUUM DESULFURIZATION ACTIVITY TESTS
Used Fresh Used Used Used Segregated &
Catalvst As Received Segregated Regenerated Regenerated Vanadium, W % 10.40 7.67 13.25 10.05 Nickel, W % 1.70 1.29 1.94 1.52 Molybdenum, W % 4.97 5.55 5.59 6.90 rarbon~ W % 19.03 24.24 0.10 0.14 Sulfur, W % 12.0 9.42 5.69 5.76 C.B.D.**, g/cm3 0.590 1.169 1.127 0.902 0.850 Pore Volume cm jg0.690 0.293* 0.255* 0.447* 0.589*
Surface Area, m2/g 288 57* 30* 106* 164*
Particle Dens., g/cm3 3.202 2.561 2.561 3.068 3.254 *Corrected to Fresh Catalyst Basis **Ccmpared Bulk Density
Claims (12)
1. A method of separating used catalyst particles into a lighter less contaminated fraction and a heavier more contam-inated fraction by density difference, comprising:
(a) removing used catalyst from a reaction zone;
(b) placing the catalyst in a single generally vertical column containing a liquid, said vertical column having a length to diameter ratio (L/D) of at least about 4/1, and said liquid having a specific gravity of between about 0.65 and about 1.2;
(c) fluidizing the catalyst bed by flowing the liquid upwardly through the catalyst at non-reaction conditions and at a superficial velocity of at least about 0.04 ft./sec., sufficient to expand the bed by at least about 20% over its settled height, and for sufficient time to accomplish substan-tial segregation of catalyst particles into upper less contam-inated fractions and lower more contaminated fractions accord-ing to their particle density;
(d) removing the upper fraction of catalyst and returning it to the reaction zone for reuse; and (e) removing the lower fraction of catalyst.
(a) removing used catalyst from a reaction zone;
(b) placing the catalyst in a single generally vertical column containing a liquid, said vertical column having a length to diameter ratio (L/D) of at least about 4/1, and said liquid having a specific gravity of between about 0.65 and about 1.2;
(c) fluidizing the catalyst bed by flowing the liquid upwardly through the catalyst at non-reaction conditions and at a superficial velocity of at least about 0.04 ft./sec., sufficient to expand the bed by at least about 20% over its settled height, and for sufficient time to accomplish substan-tial segregation of catalyst particles into upper less contam-inated fractions and lower more contaminated fractions accord-ing to their particle density;
(d) removing the upper fraction of catalyst and returning it to the reaction zone for reuse; and (e) removing the lower fraction of catalyst.
2. The method of claim 1 wherein the catalyst bed expan-sion is 30-200% of its settled height.
3. The method of claim 1 wherein the fluidizing liquid is a light process derived liquid.
4. The method of claim 1 wherein the fluidizing liquid is a light hydrocarbon liquid.
5. The method of claim 1 wherein a used oil-free catalyst is fluidized using water.
6. The method of claim 1 wherein the catalyst particle size is 2 to 200 mesh U.S. Sieve Series.
7. The method of claim 1 wherein the used catalyst is re-generated by carbon burnoff between steps (a) and (b).
8. The method of claim 1 wherein the upper portion of segregated catalyst removed at (d) is regenerated by carbon burn off before being returned to the reaction zone.
9. The method of claim 1 wherein the lower portion of segregated catalyst removed at (e) is processed for recovery of deposited metals.
10. The method of claim 1 wherein the fluidized column of catalyst has variable cross-sectional area.
11. The method of claim 1 wherein the catalyst is screened to remove the fines portion before return of the coarse portion to the reaction zone.
12. The method of claim 1 wherein the upward liquid super-ficial velocity in step (c) is within the range of 0.06 to 0.20 ft./sec.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US95401678A | 1978-10-23 | 1978-10-23 | |
| US954,016 | 1978-10-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1159402A true CA1159402A (en) | 1983-12-27 |
Family
ID=25494829
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000338243A Expired CA1159402A (en) | 1978-10-23 | 1979-10-23 | Segregating used catalyst fractions by liquid fluidization |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1159402A (en) |
| MX (1) | MX7373E (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0535886A2 (en) * | 1991-10-02 | 1993-04-07 | Texaco Development Corporation | Separation of active catalyst particles from spent catalyst particles by air elutriation |
| US5230791A (en) * | 1991-07-03 | 1993-07-27 | Texaco Inc. | Process for the reactivation of spent alumina-supported hydrotreating catalysts |
| US5254513A (en) * | 1991-05-20 | 1993-10-19 | Texaco, Inc. | Method for the reactivation of spent alumina-supported hydrotreating catalysts |
| FR3045649A1 (en) * | 2015-12-21 | 2017-06-23 | Ifp Energies Now | METHOD FOR CONVERTING PETROLEUM LOADS COMPRISING A BOILING BED HYDROCRACKING STEP INTEGRATING A CATALYST SORTING SYSTEM |
-
1979
- 1979-10-23 MX MX845279U patent/MX7373E/en unknown
- 1979-10-23 CA CA000338243A patent/CA1159402A/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5254513A (en) * | 1991-05-20 | 1993-10-19 | Texaco, Inc. | Method for the reactivation of spent alumina-supported hydrotreating catalysts |
| US5230791A (en) * | 1991-07-03 | 1993-07-27 | Texaco Inc. | Process for the reactivation of spent alumina-supported hydrotreating catalysts |
| EP0535886A2 (en) * | 1991-10-02 | 1993-04-07 | Texaco Development Corporation | Separation of active catalyst particles from spent catalyst particles by air elutriation |
| US5209840A (en) * | 1991-10-02 | 1993-05-11 | Texaco Inc. | Separation of active catalyst particles from spent catalyst particles by air elutriation |
| EP0535886A3 (en) * | 1991-10-02 | 1993-06-02 | Texaco Development Corporation | Separation of active catalyst particles from spent catalyst particles by air elutriation |
| FR3045649A1 (en) * | 2015-12-21 | 2017-06-23 | Ifp Energies Now | METHOD FOR CONVERTING PETROLEUM LOADS COMPRISING A BOILING BED HYDROCRACKING STEP INTEGRATING A CATALYST SORTING SYSTEM |
| WO2017108378A1 (en) * | 2015-12-21 | 2017-06-29 | IFP Energies Nouvelles | Method for converting petroleum feedstocks comprising a step of ebullated-bed hydrocracking incorporating a catalyst sorting system |
Also Published As
| Publication number | Publication date |
|---|---|
| MX7373E (en) | 1988-08-19 |
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