CA2484832C - A catalyst system for combining hydrotreating and hydrocracking and a process for upgrading hydrocarbonaceous feedstocks - Google Patents
A catalyst system for combining hydrotreating and hydrocracking and a process for upgrading hydrocarbonaceous feedstocks Download PDFInfo
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Abstract
A physically intermixed catalyst system comprising two distinctly different catalytic particles, the first of which is a hydrodenitrification and/or hydrodesulfurization catalyst and the second of which is a relatively active hydrocracking catalyst wherein the catalyst particles of both catalytic components are substantially the same size, that is the effective diameter of each catalyst component is substantially the same. The catalyst system of the present invention can be layered with unmixed catalysts.
The novel systems of the present invention have been found to provide surprisingly good selectivity for liquid products and stability against catalyst fouling when used in combined hydrotreating and hydrocracking applications, and can therefore be used to provide a stable catalyst system which offers even heat distribution and reactor control in such applications.
The novel systems of the present invention have been found to provide surprisingly good selectivity for liquid products and stability against catalyst fouling when used in combined hydrotreating and hydrocracking applications, and can therefore be used to provide a stable catalyst system which offers even heat distribution and reactor control in such applications.
Description
0~ AND HYDROCRACRING AND A PROCESS
03 FOR UPGRADING IiYDROCARBONACEOUS FEEDSTOCKS v os to 11 9Af,~j~rROUND OF THE INVENTION
l~
13 Field of the Inve~p~ion is The present invention relates to a catalyst system and~.a ii process for combined hydrotreating and hydrocracking 17 operations in a single reactor bad by contacting a 18 hydrocarbonaceoue feedstock with hydrogen undar 19 hydrocracking conditions in the presence of an appropriate Z0 dual function catalyst system. In particular, the catalyst Zl system and process of this invention relate to a combined Z~ denitrif ication and/or desulfurization hydrotreating process Z3 and a hydrocracking process wherain the catalyst system Z1 exhibits surprising stability and high selectivity for ~s liquid products boiling in the transportation fuels range.
Z~ The catalyst system can be tailored to provide previously 27 unavailable flexibility with regard to the selection of the Z8 hydrocracking catalyst.
30 The dual function catalyst system of the present invention 31 comprises two randomly intermixed particulate catalysts 3Z having distinctly different catalytic functions. The first 33 catalyst is a conventional hydrodenitrification and/or 31 hydrodesulfurization catalyst having substantially no cracking activity. The second catalyst is a conventional zeolitic hydrocracking catalyst. Both catalysts are selected so that they are substantially the same size, that is, the effective diameter for each catalyst particle is substantially the same.
The novel catalyst systems of the present invention have been found to provide surprisingly good selectivity for liquid products and stability against catalyst fouling when used in combined hydrotreating and hydrocracking applications, and can therefore be used to provide a stable catalyst system which offers even heat distribution and reactor control in such applications.
Objects of Aspects of the Invention Of the many hydroconversion processes known to the petroleum refining industry, catalytic hydrotreating and catalytic hydrocracking are perhaps the two most widely applied and important. In conventional refining practice, hydrotreating is carried out using a catalysts) having as the principle function the removal of nitrogen and/or sulfur, that is catalytic hydrodenitrification and hydrodesulfurization. The product of hydrotreating is then fed to a hydrocracking process unit which uses catalysts having as the principle function hydroconversion to produce liquid products boiling in the transportation fuels range.
Hydrotreating the feedstock to a hydrocracking process unit is particularly important as nitrogen and sulfur are known to contaminate conventional hydrocracking process catalysts. Thus, hydrotreating is used to lower the nitrogen and sulfur content of the hydrocarbonaceous feedstock stream to an acceptable level before subjecting the hydrocarbons to the 0i complete hydrocracking process. In general, it is desirable 0Z to lower the nitrogen content of the hydrocarbon feedstock 03 stream to less than 5o parts per million by weight (ppm), 04 preferably less than about 10 ppm and in many cases.for 0s increased catalyst life to a level o! less than 2 ppm or os even as low as about 0.1 ppm. Similarly, it is generally desirable to lower the sulfur content of the hydrocarbon 08 feedstock stream to less than about 0.5= by weight percent, 09 preferably less than about 0.1~, and in many cases as,low as about 1 ppm.
iZ However, hydrotreating catalysts have various disadvantages.
13 Perhaps the most noted disadvantage is the tendency to foul 14 with coke or other contaminants at an excessive rats. This i5 results in shorter catalyst life than is desirable. ~ As the li catalyst fouls or deactivates, the denitrification process i7 temperature must be increased to maintain activity. When i8 the maximum temperature allowed by process and equipment 19 limitations is reached, the catalyst must be replaced or Z0 regenerated.
~i ZZ A variety of measures have been suggested to ovsrcom. the Z3 problems of catalyst deactivation in hydrotreating systems.
3~ For example, U.S. Patent 4,990,243 issued February 5, 1991 Z5 to Winslow describes a layered catalyst system for Z6 hydrodenitrification. The idea behind layered systems is to Z7 provide a catalyst system which permits the operator to Z8 control the process conditions such as temperature to allow Z9 more uniform operations while removing contaminants such as 30 nitrogen. In particular, the layered systems utilize 31 discrete catalyst layers with differing catalysts having 3Z differing activity for denitrif ication and cracking. The 33 first layer is a more active denitrification catalyst which 34 does not induce cracking reaetions. The second layer is 01 more acidic and has higher cracking activity which results oz in effective conversion of the refractory nitrogen compounds 03 not converted in the first layer.
05 U.S. Patent 4,534,852 issued on August 13, 1985 to 06 Washecheck et a1. describes a single stage hydrotreating 07 process for converting pitch to conversion process 0g feedstock. According to this process the pitch containing 09 feedstock is contacted with hydrogen and passed downwardly to through a hydrotreating zone over a stacked-bed catalyst.
ii The upper bed contains a high activity hydrotreating is catalyst, and a separate lower bed contains a high activity i3 desulfurization catalyst. The reaction product is a 11 suitable hydrocracking feedstock.
is 16 U.S. Patent 3,,923,638 issued on December 2, 1975 to 19 Hertolacini et al. describes a two-catalyst hydrocracking la process. In this process a nitrogen containing feedstock is 19 denitrified in a pretreatment zone using a 20 hydrodenitrification catalyst. The denitrified effluent is Zi passed to a hydrocracking zone. The process can be carried sZ out in a single stage.
Z~ As noted previously the product from hydrotreating can be Zs fed to a hydrocracking process unit. Modern hydrocracking 28 catalysts are generally based on zeolitic materials which Z7 may have been adapted by techniques like ammonia ion Zs exchange and various forms of calcination in order to improve the performance of the hydrocracking catalysts based 30 on such zeolites. In nearly all cases, hydrocracking 3l catalysts are formulated to provide varying degrees of 3= cracking activity depending upon the desired product slate.
33 Thus, hydrocracking catalysts which have high activity, and 0i therefore promote the exothermic cracking reactions, may not 0Z be suitable for all applications.
0, Accordingly, the general approach of catalyst manufacturers 05 has been to offer a family of catalysts tailored in activity 06 for various applications. In other words, operating flexibility is achieved by selecting from a variety of os available catalysts the one catalyst which is most suitable 09 for the specific application at hand. however, this solution has created another difficulty. Refiners have ii found that on occasion the product slate changes which they is wish to make era not possible if the choice of available i3 hydrocracking catalysts in inventory does not include the i~ particular catalyst with the activity required to produce i5 the new product slate.
Thus, it would be desirable to provide a stable i$ hydrotreating catalyst system with high denitrification 19 and/or desulfurization activity which could be used to Z0 produce a low nitrogen low sulfur feedstock to a si hydrocracking process. It would also be desirable to ZZ provide a flexible hydrocracking catalyst system which had s3 high selectivity for liquid products.
25 It would be even more desirable to provide a stable catalyst system which could be used to simultaneously carry out Z~ combined hydro~.reating and hydrocracking to selectively Z$ produce liquid products in the transportation fuels boiling s9 range.
31 Several attempts have been made to provide dual function 3Z combined hyd.rotreating and hydrocracking processes and 33 catalyst systems.
03 FOR UPGRADING IiYDROCARBONACEOUS FEEDSTOCKS v os to 11 9Af,~j~rROUND OF THE INVENTION
l~
13 Field of the Inve~p~ion is The present invention relates to a catalyst system and~.a ii process for combined hydrotreating and hydrocracking 17 operations in a single reactor bad by contacting a 18 hydrocarbonaceoue feedstock with hydrogen undar 19 hydrocracking conditions in the presence of an appropriate Z0 dual function catalyst system. In particular, the catalyst Zl system and process of this invention relate to a combined Z~ denitrif ication and/or desulfurization hydrotreating process Z3 and a hydrocracking process wherain the catalyst system Z1 exhibits surprising stability and high selectivity for ~s liquid products boiling in the transportation fuels range.
Z~ The catalyst system can be tailored to provide previously 27 unavailable flexibility with regard to the selection of the Z8 hydrocracking catalyst.
30 The dual function catalyst system of the present invention 31 comprises two randomly intermixed particulate catalysts 3Z having distinctly different catalytic functions. The first 33 catalyst is a conventional hydrodenitrification and/or 31 hydrodesulfurization catalyst having substantially no cracking activity. The second catalyst is a conventional zeolitic hydrocracking catalyst. Both catalysts are selected so that they are substantially the same size, that is, the effective diameter for each catalyst particle is substantially the same.
The novel catalyst systems of the present invention have been found to provide surprisingly good selectivity for liquid products and stability against catalyst fouling when used in combined hydrotreating and hydrocracking applications, and can therefore be used to provide a stable catalyst system which offers even heat distribution and reactor control in such applications.
Objects of Aspects of the Invention Of the many hydroconversion processes known to the petroleum refining industry, catalytic hydrotreating and catalytic hydrocracking are perhaps the two most widely applied and important. In conventional refining practice, hydrotreating is carried out using a catalysts) having as the principle function the removal of nitrogen and/or sulfur, that is catalytic hydrodenitrification and hydrodesulfurization. The product of hydrotreating is then fed to a hydrocracking process unit which uses catalysts having as the principle function hydroconversion to produce liquid products boiling in the transportation fuels range.
Hydrotreating the feedstock to a hydrocracking process unit is particularly important as nitrogen and sulfur are known to contaminate conventional hydrocracking process catalysts. Thus, hydrotreating is used to lower the nitrogen and sulfur content of the hydrocarbonaceous feedstock stream to an acceptable level before subjecting the hydrocarbons to the 0i complete hydrocracking process. In general, it is desirable 0Z to lower the nitrogen content of the hydrocarbon feedstock 03 stream to less than 5o parts per million by weight (ppm), 04 preferably less than about 10 ppm and in many cases.for 0s increased catalyst life to a level o! less than 2 ppm or os even as low as about 0.1 ppm. Similarly, it is generally desirable to lower the sulfur content of the hydrocarbon 08 feedstock stream to less than about 0.5= by weight percent, 09 preferably less than about 0.1~, and in many cases as,low as about 1 ppm.
iZ However, hydrotreating catalysts have various disadvantages.
13 Perhaps the most noted disadvantage is the tendency to foul 14 with coke or other contaminants at an excessive rats. This i5 results in shorter catalyst life than is desirable. ~ As the li catalyst fouls or deactivates, the denitrification process i7 temperature must be increased to maintain activity. When i8 the maximum temperature allowed by process and equipment 19 limitations is reached, the catalyst must be replaced or Z0 regenerated.
~i ZZ A variety of measures have been suggested to ovsrcom. the Z3 problems of catalyst deactivation in hydrotreating systems.
3~ For example, U.S. Patent 4,990,243 issued February 5, 1991 Z5 to Winslow describes a layered catalyst system for Z6 hydrodenitrification. The idea behind layered systems is to Z7 provide a catalyst system which permits the operator to Z8 control the process conditions such as temperature to allow Z9 more uniform operations while removing contaminants such as 30 nitrogen. In particular, the layered systems utilize 31 discrete catalyst layers with differing catalysts having 3Z differing activity for denitrif ication and cracking. The 33 first layer is a more active denitrification catalyst which 34 does not induce cracking reaetions. The second layer is 01 more acidic and has higher cracking activity which results oz in effective conversion of the refractory nitrogen compounds 03 not converted in the first layer.
05 U.S. Patent 4,534,852 issued on August 13, 1985 to 06 Washecheck et a1. describes a single stage hydrotreating 07 process for converting pitch to conversion process 0g feedstock. According to this process the pitch containing 09 feedstock is contacted with hydrogen and passed downwardly to through a hydrotreating zone over a stacked-bed catalyst.
ii The upper bed contains a high activity hydrotreating is catalyst, and a separate lower bed contains a high activity i3 desulfurization catalyst. The reaction product is a 11 suitable hydrocracking feedstock.
is 16 U.S. Patent 3,,923,638 issued on December 2, 1975 to 19 Hertolacini et al. describes a two-catalyst hydrocracking la process. In this process a nitrogen containing feedstock is 19 denitrified in a pretreatment zone using a 20 hydrodenitrification catalyst. The denitrified effluent is Zi passed to a hydrocracking zone. The process can be carried sZ out in a single stage.
Z~ As noted previously the product from hydrotreating can be Zs fed to a hydrocracking process unit. Modern hydrocracking 28 catalysts are generally based on zeolitic materials which Z7 may have been adapted by techniques like ammonia ion Zs exchange and various forms of calcination in order to improve the performance of the hydrocracking catalysts based 30 on such zeolites. In nearly all cases, hydrocracking 3l catalysts are formulated to provide varying degrees of 3= cracking activity depending upon the desired product slate.
33 Thus, hydrocracking catalysts which have high activity, and 0i therefore promote the exothermic cracking reactions, may not 0Z be suitable for all applications.
0, Accordingly, the general approach of catalyst manufacturers 05 has been to offer a family of catalysts tailored in activity 06 for various applications. In other words, operating flexibility is achieved by selecting from a variety of os available catalysts the one catalyst which is most suitable 09 for the specific application at hand. however, this solution has created another difficulty. Refiners have ii found that on occasion the product slate changes which they is wish to make era not possible if the choice of available i3 hydrocracking catalysts in inventory does not include the i~ particular catalyst with the activity required to produce i5 the new product slate.
Thus, it would be desirable to provide a stable i$ hydrotreating catalyst system with high denitrification 19 and/or desulfurization activity which could be used to Z0 produce a low nitrogen low sulfur feedstock to a si hydrocracking process. It would also be desirable to ZZ provide a flexible hydrocracking catalyst system which had s3 high selectivity for liquid products.
25 It would be even more desirable to provide a stable catalyst system which could be used to simultaneously carry out Z~ combined hydro~.reating and hydrocracking to selectively Z$ produce liquid products in the transportation fuels boiling s9 range.
31 Several attempts have been made to provide dual function 3Z combined hyd.rotreating and hydrocracking processes and 33 catalyst systems.
U.S. Patent 4,797,196 issued on January 10, 1989 to Kukes et al. describes a hydrocracking process having intermixed catalysts. In this process, each of the intermixed catalysts has hydrodenitrification and/or hydrodesulfurization activity as well as cracking activity, that is they both have zeolitic components and function to crack the feedstock. Thus, although one of the catalysts is predominantly a hydrotreating catalyst, each catalytic particle is dual functional.
U.S. Patent 4,210,521 issued on July 1, 1980 to Gorring et al. also describes a dual bed catalytic upgrading process for refractory hydrocarbon stocks. In this process, the refractory feedstock is first catalytically hydrotreated and the hydrotreated product is subsequently cascaded through a hydrocracking zone. The initial hydrotreating step serves to convert sulfur and nitrogen derivatives of hydrocarbons to hydrogen sulfide and ammonia while depositing metal contaminants.
U.S. Patent 4,363,719 issued on December 14, 1982 to Bousquet et al.
describes a process to improve the stability of a catalyst to be used for lowering the cloud or turbidity point and the filterability, limit temperature of gas-oils. The catalyst is a composite of a non-acidic hydrodesulfurization catalyst and a non-zeolitic silica-alumina based hydroconversion catalyst.
It is the principal object of an aspect of the present invention to provide a stable catalyst system for combined hydrotreating and hydrocracking process operations with high selectivity for liquid products in the transportation fuels boiling range. This and other objectives of aspects are accomplished by the catalyst system and process summarized below.
_7_ SUMMARY OF THE INVENTION
In accordance with an aspect of the invention, there is provided a combined hydrotreating and hydrocracking process which comprises contacting a hydrocarbonaceous feedstock with hydrogen under hydrocracking conditions in the presence of a dual function catalyst system for combined hydrotreating and hydrocracking process operations comprising two randomly intermixed distinctly different particulate catalysts, the first of which is selected from the group consisting of a hydrodenitrification, hydrodesulfurization catalyst, and a combination thereof, having substantially no cracking activity and the second of which is a hydrocracking catalyst, wherein the catalyst particles of both particulate catalysts are substantially the same size, having an effective diameter within a factor of about 4 of each other.
The foregoing catalyst system can be used to carry out combined hydrotreating and hydrocracking processes under typical hydrocracking process conditions.
DETAILED DESCRIPTION OF THE INVENTION
Those familiar with the art related to the present invention will appreciate the full scope of the catalyst system and the process summarized above and be able to practice the present invention over its full scope from a detailed description of the principal features of the catalyst system and process which follows.
The Catalyst System The dual function catalyst system of the present invention comprises a randomly intermixed combination of at least two discrete particulate catalysts.
The first catalyst is a conventional hydrotreating catalyst of the type used to carry out hydrodenitrification and/or hydrodesulfurization -s-01 reactions~having substantially no cracking activity. Those 0Z familiar with the art recognize that such catalysts 03 generally are constituted by a metal from Group VI and~~a 04 metal from Group VIII placed on a non-acidic oxide such as 05 pure alumina. The commercial catalysts generally fall into 06 one or more of the numerous nickel-molybdenum or cobalt-07 molybdenum, or nickel-tungsten, or cobalt-tungsten families.
oe Tha catalytic metals era supported by alumina or other low 09 acidic support material. Such catalysts to be useful in the l0 present invention do not have cracking activity, that.is li they are non-zeolitic non-acidic catalysts which function to is promote hydrodenitrification and/or hydrodesulfurization 13 reactions. Such catalysts are well known in the art.
i5 The second catalyst particle is a conventional zeolitic is hydrocracking catalyst of the type used to carry out i7 hydroconversion reactions to produce transportation fuels.
18 Those familiar with the art recognize that such catalysts i9 are generally based on zeolitic materials which may have Z0 been adapted by techniques like ammonia ion exchange acrd Z~ various forms of calcination. In general, suitable Zeolitic ZZ hydrocracking catalysts comprise a hydrogenation component Z3 such as a metal from Group VIB and a metal from Group VIII, Z4 their oxides, their sulf ides, and mixtures thereof and an 25 acidic support of large pore crystalline zeolitic Z6 aluminosilicate.
orie of the zeolites which is considered to be a good Z9 starting material for the manufacture of hydrocracking 30 catalysts is the well-known synthetic zeolite Y as described 31 in U.S. Patent 3,130,007 issued April 21, 1964. A number of 3Z modifications to this material have been reported one~of 33 which is ultrastable Y zeolite as described in U.S:
31 Patent 3,536,605 issued October 27, 1970. To further _g_ 0i enhance the utility of synthetic Y zeolite additional 0Z components can be added. For example, U.S. Patent 3,835,027 03 issued on September 10, 1974 to Ward et al, describes 01 hydrocracking catalysts containing at least one amorphous 05 refractory oxide, a crystalline zeolitic aluminosilicate and 06 a hydrogenation component selected from tha Group VI and 07 Group VIII metals and their sulfides and their oxides.
09 It has~been found that if the two particulate catalysts are i0 selected so that the effective diameter is substantially the il same for both the hydrotreating and the hydrocracking is catalyst particles it is possible to intermix the two 13 catalysts to provide a system which surprisingly ha: the 14 beneficial attributes of both hydrotreating and i5 hydrocracking. This is particularly surprising since it is 16 known that conventional hydrotreating catalysts are rapidly 17 fouled by coke buildup, and that conventional zeolitic 18 catalysts catalyze cracking reactions which may cause a heat 19 increase leading to coke formation at the edges of .the Z0 zeolite particle.
Zi ZZ As used herein, the term "intermixed" means that no effort Z3 is made to layer or otherwise segregate the individual Z4 hydrotreating catalyst particles from the individual Z5 hydrocracking catalyst particles. Thus, the hydrotreating Z6 catalyst particles and the hydrocracking catalyst particles Z~ are allowed to physically associate with each other in a Ze relatively random manner to form a heterogeneous physical 19 mixture. This can be accomplished prior to or during 30 catalyst loading.
3Z In order to provide a catalyst system with intermixed 33 hydrotreating and hydrocracking particles which is stable 34 and acceptable for use under conventional hydrocracking ~1~~
01 conditions, it has been found that the particle size of each 0z of the catalytic particles must be substantially the same.
03 Although there are a number of catalyst sizing conventions, 04 such as surface to volume ratio, length over diameter ratio, 05 diameter of the circumscribed circle, etc.; when comparing 06 catalysts which may have nonuniform shape we have chosen to 07 use tho effective diameter of a particle as representative 08 of its size. As used herein the term "effective diameter"
09 for a catalyst particle with a circular cross section means i0 the diameter of that cross section, and for a catalyst ii particle with;a non-circular cross section means the average iZ of the major and minor axes. The important aspect of this 13 parameter is not so much the absolute size of the particles, i~ but rather the relative size of the hydrotreating catalyst i5 particles to the size of the hydrocracking catalyst , 16 particles. ht is the central feature of the present 17 invention that for the two intermixed catalysts to form the i8 catalyst system of this invention the effective diameter of 19 each must be substantially the same. Hy "substantially the Z0 same" is meant within a factor of about 4 of each other, Zi preferably within a factor of about 2 of each other, and ZZ even more preferably within a factor of about 1.5 of each Z3 other.
ZS Therefore, it is not intended that the present invention.
Z6 should be limited by the specific size of the catalysts in Z7 question, but rather that the present invention is defined ~8 by the relative size of the particles of the two catalysts.
30 It is a principal advantage of the present invention that 31 since two conventional catalysts are randomly intermixed to 3Z form the catalyst system, it is possible to select a 33 hydrocracking catalyst which under typical conditions would 3~ be too active, that is, its heat release would be too great 1 for the equipment available, and to reduce that heat release to within 2 acceptable limitations by combining it with a select hydrotreating catalyst in 3 proportions which give the desired activity. Those familiar with the art will 4 recognize that there are an endless variety of such combinations. !n general, the ratio of hydrotreating to hydrocracking catalyst will be within the range of 6 from about 1:20 to about 20:1, preferably within the range of from about 1:10 7 to about 10:1, more preferably within the range of from about 1:5 to about 5:1.
U.S. Patent 4,210,521 issued on July 1, 1980 to Gorring et al. also describes a dual bed catalytic upgrading process for refractory hydrocarbon stocks. In this process, the refractory feedstock is first catalytically hydrotreated and the hydrotreated product is subsequently cascaded through a hydrocracking zone. The initial hydrotreating step serves to convert sulfur and nitrogen derivatives of hydrocarbons to hydrogen sulfide and ammonia while depositing metal contaminants.
U.S. Patent 4,363,719 issued on December 14, 1982 to Bousquet et al.
describes a process to improve the stability of a catalyst to be used for lowering the cloud or turbidity point and the filterability, limit temperature of gas-oils. The catalyst is a composite of a non-acidic hydrodesulfurization catalyst and a non-zeolitic silica-alumina based hydroconversion catalyst.
It is the principal object of an aspect of the present invention to provide a stable catalyst system for combined hydrotreating and hydrocracking process operations with high selectivity for liquid products in the transportation fuels boiling range. This and other objectives of aspects are accomplished by the catalyst system and process summarized below.
_7_ SUMMARY OF THE INVENTION
In accordance with an aspect of the invention, there is provided a combined hydrotreating and hydrocracking process which comprises contacting a hydrocarbonaceous feedstock with hydrogen under hydrocracking conditions in the presence of a dual function catalyst system for combined hydrotreating and hydrocracking process operations comprising two randomly intermixed distinctly different particulate catalysts, the first of which is selected from the group consisting of a hydrodenitrification, hydrodesulfurization catalyst, and a combination thereof, having substantially no cracking activity and the second of which is a hydrocracking catalyst, wherein the catalyst particles of both particulate catalysts are substantially the same size, having an effective diameter within a factor of about 4 of each other.
The foregoing catalyst system can be used to carry out combined hydrotreating and hydrocracking processes under typical hydrocracking process conditions.
DETAILED DESCRIPTION OF THE INVENTION
Those familiar with the art related to the present invention will appreciate the full scope of the catalyst system and the process summarized above and be able to practice the present invention over its full scope from a detailed description of the principal features of the catalyst system and process which follows.
The Catalyst System The dual function catalyst system of the present invention comprises a randomly intermixed combination of at least two discrete particulate catalysts.
The first catalyst is a conventional hydrotreating catalyst of the type used to carry out hydrodenitrification and/or hydrodesulfurization -s-01 reactions~having substantially no cracking activity. Those 0Z familiar with the art recognize that such catalysts 03 generally are constituted by a metal from Group VI and~~a 04 metal from Group VIII placed on a non-acidic oxide such as 05 pure alumina. The commercial catalysts generally fall into 06 one or more of the numerous nickel-molybdenum or cobalt-07 molybdenum, or nickel-tungsten, or cobalt-tungsten families.
oe Tha catalytic metals era supported by alumina or other low 09 acidic support material. Such catalysts to be useful in the l0 present invention do not have cracking activity, that.is li they are non-zeolitic non-acidic catalysts which function to is promote hydrodenitrification and/or hydrodesulfurization 13 reactions. Such catalysts are well known in the art.
i5 The second catalyst particle is a conventional zeolitic is hydrocracking catalyst of the type used to carry out i7 hydroconversion reactions to produce transportation fuels.
18 Those familiar with the art recognize that such catalysts i9 are generally based on zeolitic materials which may have Z0 been adapted by techniques like ammonia ion exchange acrd Z~ various forms of calcination. In general, suitable Zeolitic ZZ hydrocracking catalysts comprise a hydrogenation component Z3 such as a metal from Group VIB and a metal from Group VIII, Z4 their oxides, their sulf ides, and mixtures thereof and an 25 acidic support of large pore crystalline zeolitic Z6 aluminosilicate.
orie of the zeolites which is considered to be a good Z9 starting material for the manufacture of hydrocracking 30 catalysts is the well-known synthetic zeolite Y as described 31 in U.S. Patent 3,130,007 issued April 21, 1964. A number of 3Z modifications to this material have been reported one~of 33 which is ultrastable Y zeolite as described in U.S:
31 Patent 3,536,605 issued October 27, 1970. To further _g_ 0i enhance the utility of synthetic Y zeolite additional 0Z components can be added. For example, U.S. Patent 3,835,027 03 issued on September 10, 1974 to Ward et al, describes 01 hydrocracking catalysts containing at least one amorphous 05 refractory oxide, a crystalline zeolitic aluminosilicate and 06 a hydrogenation component selected from tha Group VI and 07 Group VIII metals and their sulfides and their oxides.
09 It has~been found that if the two particulate catalysts are i0 selected so that the effective diameter is substantially the il same for both the hydrotreating and the hydrocracking is catalyst particles it is possible to intermix the two 13 catalysts to provide a system which surprisingly ha: the 14 beneficial attributes of both hydrotreating and i5 hydrocracking. This is particularly surprising since it is 16 known that conventional hydrotreating catalysts are rapidly 17 fouled by coke buildup, and that conventional zeolitic 18 catalysts catalyze cracking reactions which may cause a heat 19 increase leading to coke formation at the edges of .the Z0 zeolite particle.
Zi ZZ As used herein, the term "intermixed" means that no effort Z3 is made to layer or otherwise segregate the individual Z4 hydrotreating catalyst particles from the individual Z5 hydrocracking catalyst particles. Thus, the hydrotreating Z6 catalyst particles and the hydrocracking catalyst particles Z~ are allowed to physically associate with each other in a Ze relatively random manner to form a heterogeneous physical 19 mixture. This can be accomplished prior to or during 30 catalyst loading.
3Z In order to provide a catalyst system with intermixed 33 hydrotreating and hydrocracking particles which is stable 34 and acceptable for use under conventional hydrocracking ~1~~
01 conditions, it has been found that the particle size of each 0z of the catalytic particles must be substantially the same.
03 Although there are a number of catalyst sizing conventions, 04 such as surface to volume ratio, length over diameter ratio, 05 diameter of the circumscribed circle, etc.; when comparing 06 catalysts which may have nonuniform shape we have chosen to 07 use tho effective diameter of a particle as representative 08 of its size. As used herein the term "effective diameter"
09 for a catalyst particle with a circular cross section means i0 the diameter of that cross section, and for a catalyst ii particle with;a non-circular cross section means the average iZ of the major and minor axes. The important aspect of this 13 parameter is not so much the absolute size of the particles, i~ but rather the relative size of the hydrotreating catalyst i5 particles to the size of the hydrocracking catalyst , 16 particles. ht is the central feature of the present 17 invention that for the two intermixed catalysts to form the i8 catalyst system of this invention the effective diameter of 19 each must be substantially the same. Hy "substantially the Z0 same" is meant within a factor of about 4 of each other, Zi preferably within a factor of about 2 of each other, and ZZ even more preferably within a factor of about 1.5 of each Z3 other.
ZS Therefore, it is not intended that the present invention.
Z6 should be limited by the specific size of the catalysts in Z7 question, but rather that the present invention is defined ~8 by the relative size of the particles of the two catalysts.
30 It is a principal advantage of the present invention that 31 since two conventional catalysts are randomly intermixed to 3Z form the catalyst system, it is possible to select a 33 hydrocracking catalyst which under typical conditions would 3~ be too active, that is, its heat release would be too great 1 for the equipment available, and to reduce that heat release to within 2 acceptable limitations by combining it with a select hydrotreating catalyst in 3 proportions which give the desired activity. Those familiar with the art will 4 recognize that there are an endless variety of such combinations. !n general, the ratio of hydrotreating to hydrocracking catalyst will be within the range of 6 from about 1:20 to about 20:1, preferably within the range of from about 1:10 7 to about 10:1, more preferably within the range of from about 1:5 to about 5:1.
9 One such combination which has been found to be particularly effective uses a conventional commercially available nickel-molybdenum hydrotreating 11 catalyst comprising about 3.1 weight percent nickel and about 16 weight 12 percent molybdenum with the balance being phosphorous and alumina; and a 13 Hydrocracking catalyst which is a comulled zeolitic catalyst comprising about 14 17 weight percent aiumina binder, about 12 weight percent molybdenum, about 4 weight percent nickel, about 30 weight percent y-zeolite, and about 30 16 weight percent amorphous silica/alumina. This more general hydrocracking 17 catalyst comprises a Y zeoiite having a unit cell size greater than about 24.55 18 Angstroms and a crystal size less than about 2.8 microns together with an 19 amorphous cracking component, a binder, and at least one hydrogenation component selected from the group consisting of a Group VI metal and/or 21 Group viii metal and mixtures thereof.
23 In preparing a Y zeolite for use in accordance with the invention herein, the 24 process as disclosed in U.S, patent 0i Ho. 3,808,'26 should be followed to produce a Y zeolite 0Z having a crystal size less than about 2.8 microns.
More specifically, the hydrocracking catalyst suitably 05 comprises from about 308-908 by weight of Y zaolite~,and os amorphous cracking component, and from about 7O~t-108 by 09 weight of binder. Preferably, the catalyst comprises rather oe high amounts of Y zeolite and amorphous cracking component, 09 that is, from about 608-908 by weight of Y zeolite and i0 amorphous cracking component, and from about 408-108 by ii weight of binder, and being particularly preferred from is about 808-8~58~by weight of Y zeolita and amorphous cracking i3 component, and from about 208-158 by weight of binder.
14 preference is given to the use of silica-alumina as the is amorphous cracking component.
is i7 The amount of Y zeolite in the catalyst ranges from about 16 5-708 by weight of the combined amount of zeolite and 19 cracking component. Preferably, the amount of Y zeolite in 20 the catalyst compositions ranges from about 108-60~~by Zi weight of the combined amount of zeolite and cracking ZZ component, and most preferably the amount of Y zeolite in Z3 the catalyst compositions ranges from about 15-40~ by.weight Z4 of the combined amount of zeolite and cracking component.
zs Zs Depending on the desired unit cell size, the S102/A1z03 Z~ molar ratio of the Y zeolite may have to be adjusted. There Z8 are many techniques described in the art which can be Z9 applied to adjust the unit cell size accordingly. It has 30 been found that Y zeolites having a S102/A1203 molar ratio 31 from about 3 to about 30 can be suitably applied as the 3Z zeolite component of the catalyst compositions according to 33 the present invention. Preference is given to Y zeolites 0i having a molar S102/A1203 ratio from about 4 to about i2, 0Z and most preferably having a molar SiOZ/A1203 ratio from S
03 about 5 to about s.
0s The amount of cracking component such as silica-alumina in 06 the hydrocracking catalyst ranges from about lOt-50t by weight, preferably from about 25~-35~ by weight. The amount of silica in the silica-alumina ranges from about 10~-70~ by 09 weight. Preferably, the amount of silica in the i0 silica-alumina ranges from about 20~-60~ by weight, and most ii preferably the amount of silica in the silica-alumina ranges i? from about 25~-50~ by weight. Also, so-called X-ray i3 amorphous zeolites (i.e., zeolitas having crystallite sizes i~ too small to be detected by standard X-ray techniques) can is be suitably applied as cracking components according to the i6 process embodiment of the present invention.
i7 i8 The binders) present in the hydrocracking catalyst suitably i9 comprise inorganic oxides. Both amorphous and crystalline binders cnn be applied. Examples of suitable binders ~i comprise silica, alumina, clays and zirconia. Preference is ZZ given to the use of alumina as binder.
Z4 The amounts) of hydrogenation components) in the catalyst Zs suitably range from about 0.5~ to about 10t by weight of Group VIII metal components) and from about 5t to about 25=
by weight o! Group VI metal component(s), calculated as Z8 metals) per 100 parts by weight of total catalyst. The Z9 hydrogenation components in the catalyst may be in the 30 oxidic and/or the sulphidic fona. If a combination of at 31 least a Group VI and a Group VIII metal component is present 3Z as (mixed) oxides, it will be subjected to a sulphiding 33 treatment prior to proper use in hydrocracking.
of Suitably, the catalyst comprises one or more components o!
os nickel and/or cobalt and one or more components of 03 molybdenum and/or tungsten or one or more components of 01 platinum and/or palladium.
os 06 The hydrocracking catalyst comprises from about 3~-lOt by 07 weight of nickel and from about 5~-20t by weight molybdenum.
0o Preferably, the catalyst comprises from about 4~-8~ by 09 weight'of nickel and from about 8~-15~ by weight molybdenum, to calculated as metals per 100 parts by weight of total ii catalyst.
is 13 The effective diameter of the hydrotreating catalyst 11 particles was about 0.1 inch, and the effective diameter of 15 the hydrocracking catalyst particles was also about 0.1 li inch. The two catalysts are intermixed in a weight ratio of i7 about 1.5:1 hydrotreating to hydrocracking catalyst.
li 19 The catalyst system of the present invention can be used in Z0 a variety of configurations. For example, the dual~function Zi system of this invention can be layered with unmixed Z3 hydrotreating and/or hydrocracking catalysts. In a Z3 preferred configuration a single reactor may contain up to Z~ four beds, up to about 60~ by volume of the first bed being ZS unmixed hydrotreating catalyst, from about 10~ by volume of Z6 the second bed being the catalyst system of the present Z7 invention, up to about 50~ by volume of the third bed being Ze unmixed hydrocracking catalyst, and up to about 40t by Z9 volume of the fourth bed being unmixed hydrotreating 30 catalyst.
3Z Having described in detail the catalyst system which is used 33 in the process of the present invention, it is appropriate 31 to consider the second aspect of the present process.
0i ' Process Conditions 03 The process of the present invention is a combined hydrotreating and hydrocracking process which comprises 05 contacting a hydrocarbonaceous feedstock with hydrogen under 0' typical hydrocracking conditions in the presence of the dual 09 function catalyst system detailed above.
os 09 Representative feedstocks include petroleum crude oils, topped or reduced crude oils, solvent deasphalted oils, ii distillates, etc. Preferred feedstocks include crude i? petroleum and atmospheric and vacuum towered bottoms. These 13 feedstocks generally have boiling range above about 200~F
14 and generally have a boiling range between 350~F and about 1050°F. More specifically these feedstocke include heavy is distillates, heavy straight run gas oils and heavy cracked i9 cycle oils, as well as fluidized catalytic cracking unit ie feedstocks.
19 . _ Zo The hydrocarbonaceous feedstock is contacted with hydrogen Zi in the presence of the catalyst system under upgrading 3Z conditions which generally include a temperature in the Z3 range of from about 500~F to about 900~F, preferably between Z4 about 650~F and about 850°F.; a pressure of from about 500 ZS pounds per square inch absolute (psia) to about 3,500 psia, 36 preferably from about 1,000 psia to about 3,000 psia; and a Z~ liquid hourly space velocity (LIiSV) of from about 0.1 to Z8 about 6.0, preferably from about 0.5 to about 4; and an oil Z9 to gas ratio of from about 2,000 standard cubic feet per 3o barrel (scf/bbl) to about 10,000 scf/bbi, preferably from 3i about 3,000 scf/bbl to about 6,000 scf/bbl.
33 With the preferred catalyst system described above it has 3~ been found that preferred process conditions include 1 contacting a hydrocarbonaceous feedstock with hydrogen in the presence of 2 the physically intermixed catalyst system under hydrocracking conditions 3 comprising a pressure of about 2,300 psia, a gas to oil ratio at from about 4 4,000 scflbbl to about 5,000 scf/bbl, a LHSV of about 1.0, and a temperature in the range of from about 680°F to about 800°F.
7 These and other specific applications of the catalyst system and process of 8 the present invention are illustrated in the following example.
EXAMPLE
12 The following example illustrates the efficacy of the present invention.
14 A dual catalyst system was prepared by physically intermixing a commercially available nickel-molybdenum hydrotreating catalyst comprising about 3.1 16 weight percent nickel and about 16 weight percent molybdenum with the 17 balance being phosphorous and alumina; and a zeolitic hydrocracking catalyst 18 which is a comulled zeolitic catalyst comprising about 17 weight percent 19 alumina binder, about 12 weight percent molybdenum, about 4 weight percent nickel, about 30 weight percent Y-zeolite, and about 30 weight percent 21 amorphous silica/alumina. This hydrocracking catalyst was prepared by the 22 mufti-step process wherein Solution "A" was prepared by dissolving 160.6 g 23 nickel nitrate hexa hydrate (Ni(N0~ )2 6H20] in 70 cc deionized of water and then adding about 25 g concentrated nitric acid os ~70~ xNO3) .
04 Solution "H" was a molybdenum solution prepared by stirring 05 and filtering a mixture composed of 26.5 weight percent 06 concentrated aqueous NH408, 28.9 weight percent Mo03, balance deionized water.
09 A solid mixture was prepared by mixing 174.7 grams alumina io powder, 293.8 grams Si02/A1Z03 powder, and 303.8 grams ultra ii stable Y zeolite powder in a sigma-blade mixer for 5 minutes 13 at about 150~F mixer jacket temperature. To the solid 13 mixture was then added about 150 cc of deionized water, and the mixture mixed an additional 5 minutes. Solution »A" was 15 then added to the wet solid mixture, and the mixing was i6 continued for an additional 35 minutes.
i7 18 qg3.1 grams o! Solution "H" were then dripped into the wet i9 Solid mixture over a 5-minute period. 70 cc deionized water 3o were added, and the wet solid mixture was mixed for an additional 15 minutes.
ZZ
Z3 The wet mixture was extruded in a 2-inch Bonnot extruder.
34 The extrudates were dried in a preheated oven at 320~F for 35 1 hour. They were then heated to 950~F at 288~F/hr in com dry air,~held for 1 hour at 950°F, and then cooled to room temperature.
ss Z9 The effective diameter of the hydrotreating catalyst 30 particles was about 0.1 inch, and the effective diameter of 3i the hydrocracking catalyst particles was also about 0.1 inch. The two catalysts are intermixed in a weight ratio of 33 abput 1.5:1 hydrotreating to hydrocracking catalyst.
0i A feedstock of heavy gas oil having the following 0Z characteristics was contacted with above dual catalyst 03 system in the presence of hydrogen:
os API Gravity - 21.0 06 Nitrogen - 2520 ppm 07 Sulfur - 0.8 weight percent 08 D2887 Simulated Distillation 09 St - 380°F
i0 50~ - 742~F
il EP - 952°F
i2 13 The process conditions were maintained as follows:
is i.o Lxsv 16 2,300 prig total pressure 17 5,500 scf/bbl gas rate 18 680°F-800°F temperature range i!
Z0 At a target product composition of 1.0 ppm nitrogen and 10 Zi ppm sulfur, the dual catalyst system resulted in a 17°F
ZZ higher activity and 80~ improvement in catalyst life Z3 relative to a conventional layered catalyst system Z~ comprising 60 volume percent of a commercial zeolitic Zs catalyst and 40 volume percent of a commercial nonzeolitic Z6 silica/alumina catalyst.
Ze There are numerous variations on the present invention which Z9 are possible in light of the teachings and example 30 supporting the present invention. It is therefore 3i understood that within the scope of the following claims, 3Z the invention may be practiced otherwise than as 33 specifically described or exemplified herein.
23 In preparing a Y zeolite for use in accordance with the invention herein, the 24 process as disclosed in U.S, patent 0i Ho. 3,808,'26 should be followed to produce a Y zeolite 0Z having a crystal size less than about 2.8 microns.
More specifically, the hydrocracking catalyst suitably 05 comprises from about 308-908 by weight of Y zaolite~,and os amorphous cracking component, and from about 7O~t-108 by 09 weight of binder. Preferably, the catalyst comprises rather oe high amounts of Y zeolite and amorphous cracking component, 09 that is, from about 608-908 by weight of Y zeolite and i0 amorphous cracking component, and from about 408-108 by ii weight of binder, and being particularly preferred from is about 808-8~58~by weight of Y zeolita and amorphous cracking i3 component, and from about 208-158 by weight of binder.
14 preference is given to the use of silica-alumina as the is amorphous cracking component.
is i7 The amount of Y zeolite in the catalyst ranges from about 16 5-708 by weight of the combined amount of zeolite and 19 cracking component. Preferably, the amount of Y zeolite in 20 the catalyst compositions ranges from about 108-60~~by Zi weight of the combined amount of zeolite and cracking ZZ component, and most preferably the amount of Y zeolite in Z3 the catalyst compositions ranges from about 15-40~ by.weight Z4 of the combined amount of zeolite and cracking component.
zs Zs Depending on the desired unit cell size, the S102/A1z03 Z~ molar ratio of the Y zeolite may have to be adjusted. There Z8 are many techniques described in the art which can be Z9 applied to adjust the unit cell size accordingly. It has 30 been found that Y zeolites having a S102/A1203 molar ratio 31 from about 3 to about 30 can be suitably applied as the 3Z zeolite component of the catalyst compositions according to 33 the present invention. Preference is given to Y zeolites 0i having a molar S102/A1203 ratio from about 4 to about i2, 0Z and most preferably having a molar SiOZ/A1203 ratio from S
03 about 5 to about s.
0s The amount of cracking component such as silica-alumina in 06 the hydrocracking catalyst ranges from about lOt-50t by weight, preferably from about 25~-35~ by weight. The amount of silica in the silica-alumina ranges from about 10~-70~ by 09 weight. Preferably, the amount of silica in the i0 silica-alumina ranges from about 20~-60~ by weight, and most ii preferably the amount of silica in the silica-alumina ranges i? from about 25~-50~ by weight. Also, so-called X-ray i3 amorphous zeolites (i.e., zeolitas having crystallite sizes i~ too small to be detected by standard X-ray techniques) can is be suitably applied as cracking components according to the i6 process embodiment of the present invention.
i7 i8 The binders) present in the hydrocracking catalyst suitably i9 comprise inorganic oxides. Both amorphous and crystalline binders cnn be applied. Examples of suitable binders ~i comprise silica, alumina, clays and zirconia. Preference is ZZ given to the use of alumina as binder.
Z4 The amounts) of hydrogenation components) in the catalyst Zs suitably range from about 0.5~ to about 10t by weight of Group VIII metal components) and from about 5t to about 25=
by weight o! Group VI metal component(s), calculated as Z8 metals) per 100 parts by weight of total catalyst. The Z9 hydrogenation components in the catalyst may be in the 30 oxidic and/or the sulphidic fona. If a combination of at 31 least a Group VI and a Group VIII metal component is present 3Z as (mixed) oxides, it will be subjected to a sulphiding 33 treatment prior to proper use in hydrocracking.
of Suitably, the catalyst comprises one or more components o!
os nickel and/or cobalt and one or more components of 03 molybdenum and/or tungsten or one or more components of 01 platinum and/or palladium.
os 06 The hydrocracking catalyst comprises from about 3~-lOt by 07 weight of nickel and from about 5~-20t by weight molybdenum.
0o Preferably, the catalyst comprises from about 4~-8~ by 09 weight'of nickel and from about 8~-15~ by weight molybdenum, to calculated as metals per 100 parts by weight of total ii catalyst.
is 13 The effective diameter of the hydrotreating catalyst 11 particles was about 0.1 inch, and the effective diameter of 15 the hydrocracking catalyst particles was also about 0.1 li inch. The two catalysts are intermixed in a weight ratio of i7 about 1.5:1 hydrotreating to hydrocracking catalyst.
li 19 The catalyst system of the present invention can be used in Z0 a variety of configurations. For example, the dual~function Zi system of this invention can be layered with unmixed Z3 hydrotreating and/or hydrocracking catalysts. In a Z3 preferred configuration a single reactor may contain up to Z~ four beds, up to about 60~ by volume of the first bed being ZS unmixed hydrotreating catalyst, from about 10~ by volume of Z6 the second bed being the catalyst system of the present Z7 invention, up to about 50~ by volume of the third bed being Ze unmixed hydrocracking catalyst, and up to about 40t by Z9 volume of the fourth bed being unmixed hydrotreating 30 catalyst.
3Z Having described in detail the catalyst system which is used 33 in the process of the present invention, it is appropriate 31 to consider the second aspect of the present process.
0i ' Process Conditions 03 The process of the present invention is a combined hydrotreating and hydrocracking process which comprises 05 contacting a hydrocarbonaceous feedstock with hydrogen under 0' typical hydrocracking conditions in the presence of the dual 09 function catalyst system detailed above.
os 09 Representative feedstocks include petroleum crude oils, topped or reduced crude oils, solvent deasphalted oils, ii distillates, etc. Preferred feedstocks include crude i? petroleum and atmospheric and vacuum towered bottoms. These 13 feedstocks generally have boiling range above about 200~F
14 and generally have a boiling range between 350~F and about 1050°F. More specifically these feedstocke include heavy is distillates, heavy straight run gas oils and heavy cracked i9 cycle oils, as well as fluidized catalytic cracking unit ie feedstocks.
19 . _ Zo The hydrocarbonaceous feedstock is contacted with hydrogen Zi in the presence of the catalyst system under upgrading 3Z conditions which generally include a temperature in the Z3 range of from about 500~F to about 900~F, preferably between Z4 about 650~F and about 850°F.; a pressure of from about 500 ZS pounds per square inch absolute (psia) to about 3,500 psia, 36 preferably from about 1,000 psia to about 3,000 psia; and a Z~ liquid hourly space velocity (LIiSV) of from about 0.1 to Z8 about 6.0, preferably from about 0.5 to about 4; and an oil Z9 to gas ratio of from about 2,000 standard cubic feet per 3o barrel (scf/bbl) to about 10,000 scf/bbi, preferably from 3i about 3,000 scf/bbl to about 6,000 scf/bbl.
33 With the preferred catalyst system described above it has 3~ been found that preferred process conditions include 1 contacting a hydrocarbonaceous feedstock with hydrogen in the presence of 2 the physically intermixed catalyst system under hydrocracking conditions 3 comprising a pressure of about 2,300 psia, a gas to oil ratio at from about 4 4,000 scflbbl to about 5,000 scf/bbl, a LHSV of about 1.0, and a temperature in the range of from about 680°F to about 800°F.
7 These and other specific applications of the catalyst system and process of 8 the present invention are illustrated in the following example.
EXAMPLE
12 The following example illustrates the efficacy of the present invention.
14 A dual catalyst system was prepared by physically intermixing a commercially available nickel-molybdenum hydrotreating catalyst comprising about 3.1 16 weight percent nickel and about 16 weight percent molybdenum with the 17 balance being phosphorous and alumina; and a zeolitic hydrocracking catalyst 18 which is a comulled zeolitic catalyst comprising about 17 weight percent 19 alumina binder, about 12 weight percent molybdenum, about 4 weight percent nickel, about 30 weight percent Y-zeolite, and about 30 weight percent 21 amorphous silica/alumina. This hydrocracking catalyst was prepared by the 22 mufti-step process wherein Solution "A" was prepared by dissolving 160.6 g 23 nickel nitrate hexa hydrate (Ni(N0~ )2 6H20] in 70 cc deionized of water and then adding about 25 g concentrated nitric acid os ~70~ xNO3) .
04 Solution "H" was a molybdenum solution prepared by stirring 05 and filtering a mixture composed of 26.5 weight percent 06 concentrated aqueous NH408, 28.9 weight percent Mo03, balance deionized water.
09 A solid mixture was prepared by mixing 174.7 grams alumina io powder, 293.8 grams Si02/A1Z03 powder, and 303.8 grams ultra ii stable Y zeolite powder in a sigma-blade mixer for 5 minutes 13 at about 150~F mixer jacket temperature. To the solid 13 mixture was then added about 150 cc of deionized water, and the mixture mixed an additional 5 minutes. Solution »A" was 15 then added to the wet solid mixture, and the mixing was i6 continued for an additional 35 minutes.
i7 18 qg3.1 grams o! Solution "H" were then dripped into the wet i9 Solid mixture over a 5-minute period. 70 cc deionized water 3o were added, and the wet solid mixture was mixed for an additional 15 minutes.
ZZ
Z3 The wet mixture was extruded in a 2-inch Bonnot extruder.
34 The extrudates were dried in a preheated oven at 320~F for 35 1 hour. They were then heated to 950~F at 288~F/hr in com dry air,~held for 1 hour at 950°F, and then cooled to room temperature.
ss Z9 The effective diameter of the hydrotreating catalyst 30 particles was about 0.1 inch, and the effective diameter of 3i the hydrocracking catalyst particles was also about 0.1 inch. The two catalysts are intermixed in a weight ratio of 33 abput 1.5:1 hydrotreating to hydrocracking catalyst.
0i A feedstock of heavy gas oil having the following 0Z characteristics was contacted with above dual catalyst 03 system in the presence of hydrogen:
os API Gravity - 21.0 06 Nitrogen - 2520 ppm 07 Sulfur - 0.8 weight percent 08 D2887 Simulated Distillation 09 St - 380°F
i0 50~ - 742~F
il EP - 952°F
i2 13 The process conditions were maintained as follows:
is i.o Lxsv 16 2,300 prig total pressure 17 5,500 scf/bbl gas rate 18 680°F-800°F temperature range i!
Z0 At a target product composition of 1.0 ppm nitrogen and 10 Zi ppm sulfur, the dual catalyst system resulted in a 17°F
ZZ higher activity and 80~ improvement in catalyst life Z3 relative to a conventional layered catalyst system Z~ comprising 60 volume percent of a commercial zeolitic Zs catalyst and 40 volume percent of a commercial nonzeolitic Z6 silica/alumina catalyst.
Ze There are numerous variations on the present invention which Z9 are possible in light of the teachings and example 30 supporting the present invention. It is therefore 3i understood that within the scope of the following claims, 3Z the invention may be practiced otherwise than as 33 specifically described or exemplified herein.
Claims (5)
1. A combined hydrotreating and hydrocracking process which comprises contacting a hydrocarbonaceous feedstock with hydrogen under hydrocracking conditions in the presence of a dual function catalyst system for combined hydrotreating and hydrocracking process operations comprising two randomly intermixed distinctly different particulate catalysts, the first of which is selected from the group consisting of a hydrodenitrification, hydrodesulfurization catalyst, and a combination thereof, having substantially no cracking activity and the second of which is a hydrocracking catalyst, wherein the catalyst particles of both particulate catalysts are substantially the same size, having an effective diameter within a factor of about 4 of each other.
2. A process according to claim 1, wherein the hydrocarbonaceous feedstock is contacted with hydrogen in the presence of the catalyst system under upgrading conditions comprising a temperature in the range of from about 500°F to about 900°F; a pressure of from about 500 psia to about 3,500 psia; a LHSV of from about 0.1 to about 6.0;
and an oil to gas ratio of from about 2,000 scf/bbl to about 10, 000 scf/bbl.
and an oil to gas ratio of from about 2,000 scf/bbl to about 10, 000 scf/bbl.
3. A process according to claim 1, wherein the hydrocarbonaceous feedstock is contacted with hydrogen in the presence of the catalyst system under upgrading conditions comprising a temperature in the range of from about 650°F and about 850°F; a pressure of from about 1,000 psia to about 3,000 psia; a LHSV from about 0.5 to about 4; and oil to gas ratio of from about 3,000 scf/bbl to about 6,000 scf/bbl.
4. A process according to claim 1, wherein said hydrocracking conditions comprise a pressure of about 2,300 psia, a gas to oil ratio at about 4,000 scf/bbl to about 5,000 scf/bbl, a LHSV of about 1.0, and a temperature in the range of from about 680°F to about 800°F.
5. A process according to claim 3, wherein the hydrocracking catalyst of the catalyst system comprises a .UPSILON. zeolite having a unit cell size greater than about 24.55 Angstroms and a crystal size less than about 2.8 microns together with an amorphous cracking component, a binder, and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal, and mixtures thereof.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86966692A | 1992-04-16 | 1992-04-16 | |
| US07/869,666 | 1992-04-16 | ||
| CA002119446A CA2119446C (en) | 1992-04-16 | 1993-04-09 | A catalyst system for combining hydrotreating and hydrocracking and a process for upgrading hydrocarbonaceous feedstocks |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002119446A Division CA2119446C (en) | 1992-04-16 | 1993-04-09 | A catalyst system for combining hydrotreating and hydrocracking and a process for upgrading hydrocarbonaceous feedstocks |
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| Publication Number | Publication Date |
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| CA2484832A1 CA2484832A1 (en) | 1993-10-28 |
| CA2484832C true CA2484832C (en) | 2006-10-31 |
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| CA002484832A Expired - Fee Related CA2484832C (en) | 1992-04-16 | 1993-04-09 | A catalyst system for combining hydrotreating and hydrocracking and a process for upgrading hydrocarbonaceous feedstocks |
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| Country | Link |
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| CA (1) | CA2484832C (en) |
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