CA1246525A - Modified zsm-5 catalyst, and method of preparation and use thereof - Google Patents
Modified zsm-5 catalyst, and method of preparation and use thereofInfo
- Publication number
- CA1246525A CA1246525A CA000485132A CA485132A CA1246525A CA 1246525 A CA1246525 A CA 1246525A CA 000485132 A CA000485132 A CA 000485132A CA 485132 A CA485132 A CA 485132A CA 1246525 A CA1246525 A CA 1246525A
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- zsm
- crystalline material
- hydrocarbon
- olefins
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Catalysts (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
MODIFIED ZSM-5 CATALYST, AND
METHOD OF PREPARATION AND USE THEREOF
ABSTRACT
Modified ZSM-5 catalyst is prepared by controlled aging in a moving bed catalytic cracking unit. The modified catalyst exhibits significant olefin isomerization activity and reduced paraffin cracking activity.
METHOD OF PREPARATION AND USE THEREOF
ABSTRACT
Modified ZSM-5 catalyst is prepared by controlled aging in a moving bed catalytic cracking unit. The modified catalyst exhibits significant olefin isomerization activity and reduced paraffin cracking activity.
Description
~2~
F 2909 ' - 1 -_7 _ _ .
MEil~)D OF PREPARATION AMD USE TE~OF
The invention relates to an improved ZSM-5 zeolite, its method of preparation, and use of the zeoli~e in hydrocarbon conversion processes.
Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conv~rsions. Certain zeolites are ordered, porous crystalline aluminosilicat~s having a definite crystalline structure within which there are a large number of smaller cavities which may be interconnected by still smaller channels. These materials are known as molecular sieves.
Many methods have been developed for preparing a variety of synthetic aluminosilicates. These aluminosilicates have come to be designated by letter or other symbol, e.g., Zeolite A (U.S. Patent No.
F 2909 ' - 1 -_7 _ _ .
MEil~)D OF PREPARATION AMD USE TE~OF
The invention relates to an improved ZSM-5 zeolite, its method of preparation, and use of the zeoli~e in hydrocarbon conversion processes.
Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conv~rsions. Certain zeolites are ordered, porous crystalline aluminosilicat~s having a definite crystalline structure within which there are a large number of smaller cavities which may be interconnected by still smaller channels. These materials are known as molecular sieves.
Many methods have been developed for preparing a variety of synthetic aluminosilicates. These aluminosilicates have come to be designated by letter or other symbol, e.g., Zeolite A (U.S. Patent No.
2,882,243), Zeolite X (U.S. Patent No. 2,882,244), Zeolite Y (U.S~
Patent No. 3,130,007), and ZSM-5 (U.S. Patent No. 3,702,886).
ZSM-5 is a particularly interesting zeolite, and much work with ZSM-5 has been reported in the patent literature on adding an inter~ediate pore size zeolite, e.g., ZSM-5, to the conventional cracking catalyst. Use of large pore and small pore crystalline materials in catalytic cracking is known. Quite a lot of work has been done adding ZS~-5, and related intermediate pore size zeolites, to conventional large pore cracking catalyst.
In U.S. Patent No. 3,758,403, from 2.05 to lO~ ZSM-5 catalyst was added to a conven~ional cracking catalyst containing 10% REY, the remainder being Georgia clay. Examples were given showing use of 1.5, 2.5, 5 and lO w* ~ ZSM-5 added to the conventional cracking catalyst.
The ZSM-5 catalyst resulted in increased production of dry gas, some loss of gasoline yield, and an increase in octane number.
ZSM-5 catalyst, especially, virgin catalyst, has exceedingly high activity. Researchers have attempted to take advantage of the , :~2~S25 F-2909 : 2 -super activity of fresh ZSM-5 catalysts by adding only small amounts of it to FCC catalyst. Typical of such work is U.S. Patent No.
4,3091280 ~hich taught adding ve~y small amounts of powdered neat ZS~-5 catalyst, characterized by a particle si~e less than 5 microns.
s This patent taught that adding as little as 0.25 w* % ZSM-5 powder to the circulating catalyst inventory in an FCC unit would increase dry gas production by 50% (fro~ 3.9 wt % dry gas to 6.0 - see Example 6 in Table 2).
To summarize the state of the art regards addition of ~SM-5 to cracking catalyst, the following general statements can be made.
ZSM-5 is exceedingly active, and addition of even small amounts results in grea~ly augmented production of dry gas, at the expense of gasoline yield.
So far as is known to applicants, no use has been made on a commercial or long term scale of ZSM-5 in moving bed catalytic cracking processes.
Experimental work has shown that ZSM-5 catalyst, in FCC
; processes, loses activity relatively quickly. ZSM-5 is disproportionately active, compared to conventional PCC catalyst, from startup up to perhaps as much as a week of operation. After more than about a week of operation in an FCC unit, and after being subjected to repeated fluidized bed regenerations, in laboratory or in commercial units, the ZSM-5 activity becomes much harder to find.
~` These factors, high initial activity of ZSM-5, coupled with rapid deactivation of ZSM-5, discouraged researchers fro~ adding ZSM-5 to moving bed catalytic cracking units. The high startup activity of ZSM-5 results in voluminous production of light gases, which production is difficult to accommodate in downstream processing units designed to handle the product mix obtained from conventional catalyst. The rapid deactivation of ZSM 5 meant that its effect would soon be lost, requiring very expensive turnover of catalyst in the unit.
The problem of accommodating the initial high activity of ZSM-5 catalyst, has been solvedl and is discussed hereafter.
~2~5~5 P-2909 ` ~ 3 -The expected rapid catalyst deactivation~ based on projections of work using ZSM-5 catalyst in FCC units, did not occur in TCC units.
The properties of the ZSM-5 catalyst changed after repeated regenerations in a moving bed cracking unit.
It was expected that the catalys~ would lose activity. It did, but not nearly to the same extent as it did in conventional FCC
catalyst regenerations.
Surprisingly, the ZSM-5 catalyst changed during use, and behaved differently than it ever had before. It did not just get older, it got better.
As the feeds are substantially the same in FCC and TCC, it is postulated that the different reaction/regeneration me~hods used in these processes might be the cause of the change in the ZSM-5 catalyst.
~here is a difference in the severity and frequency of catalyst regeneration in TCC and FCC units.
FCC catalyst is frequently regenerated at temperatures of 650-732~C (1200-1350F) in a fluidized bed regenerator. Any hydrogen, or hydrocarbon, present on the catalyst burns to produce water. The water, or steam, deactivates the ZSM-5 catalyst fairly rapidly.
In contrast, in Thermofor catalytic cracking regeneration, the catalyst is regenerated in a moving bed. Hydrogen and hydrocarbon tend to be burned off the catalyst and swept away from it before coke on the catalyst is burned, and before very high tenperatures necessary to burn off coke are reached. In TCC regeneration the catalyst does not see water vapor for a very long time, and when it does see water vapor the catalyst is not very hot so the steaning deactivation effect is not so severe as in FCC.
Even making adjustments for the severity and frequency of FCC
regenerations vs. TCC regenerations, the ZSM-5 catalyst after regeneration in a TCC unit behaved differently than ZSM-5 catalyst regenerated in an FCC unit.
After many days of operation in a TCC unit, the Z~M-5 catalyst became a better catalyst. Some activity was lost, but significant and unexpected amounts of catalytic activity remained. Most significant, the aged, TCC regenerated ZSM-5 catalyst retained most of the virtues ~ 2~
F-29~9 - 4 -expected of ZSM-5 catalyst ~increased product octans number), while shedding most of the defects of ZSM-5 catalyst (loss in gasoline yield, increased dry gas make).
Accordingly, the present invention provides a crystalline material having the crystal structure of ZSM-5 which, when in contact with long chain relatively low octane olefins, at hydrocarbon conversion conditions sufficient to convert at least a portion of the olefins, exhibits as a primary conversion mechanism the isomerization of the long chain olefins to higher octane number materials.
In another embodimen~, the present invention provides a catalytic cracking process operating in the absence of additional hydrogen, wherein hydrocarbon feedstock is contacted with a catalyst and the feedstock is cracked to lighter products, characterized by adding a crystalline material having the crystal structure of ZSM-5 and having a reduced paraffin cracking activity, and exhibiting substantial olefin isomerization activity, as compared to conventional ZSM-5 catalyst.
In yet another embodiment, the present invention provides modified ZSM-5 catalyst characterized by its method of preparation comprising contacting hydrocarbons with ZSM-5 catalyst initially having substantial initial paraffin cracking ac~ivity in a catalytic cracking zone to produce coked catalyst containing minor amounts of hydrocarbon and coke regenerating the coked catalyst in catalyst regeneration zone by the steps comprising burning a majority of the hydrocarbon from the catalyst, while leaving a majority of the coke on the catalyst removing most of the products of hydrocarbon combustion fron contact with the catalyst and subsequently burning coke from the catalyst to produce a regenerated catalyst repeating steps a) and b) until the initial paraffin cracking ability of the ZSM-5 catalyst has been reduced by at least 50%~
ZSM-5 is described in U.S. Patent Nos. 3,702,886 and Re 29,948.
.
.
~24~S~5 F-Z9~9 : 5 -Quite a lot of work has been done on making material with a ZSM-5 crystal structure, but with different materials, ranging from all silica to materials containing silica and some o~her tetravalent metal such as boron, iron, gallium, etc.
As used herein, the term ZSM-5 refers to a material which has substantially the same crystal struc~ure as shown in U.S. Patent No.
Patent No. 3,130,007), and ZSM-5 (U.S. Patent No. 3,702,886).
ZSM-5 is a particularly interesting zeolite, and much work with ZSM-5 has been reported in the patent literature on adding an inter~ediate pore size zeolite, e.g., ZSM-5, to the conventional cracking catalyst. Use of large pore and small pore crystalline materials in catalytic cracking is known. Quite a lot of work has been done adding ZS~-5, and related intermediate pore size zeolites, to conventional large pore cracking catalyst.
In U.S. Patent No. 3,758,403, from 2.05 to lO~ ZSM-5 catalyst was added to a conven~ional cracking catalyst containing 10% REY, the remainder being Georgia clay. Examples were given showing use of 1.5, 2.5, 5 and lO w* ~ ZSM-5 added to the conventional cracking catalyst.
The ZSM-5 catalyst resulted in increased production of dry gas, some loss of gasoline yield, and an increase in octane number.
ZSM-5 catalyst, especially, virgin catalyst, has exceedingly high activity. Researchers have attempted to take advantage of the , :~2~S25 F-2909 : 2 -super activity of fresh ZSM-5 catalysts by adding only small amounts of it to FCC catalyst. Typical of such work is U.S. Patent No.
4,3091280 ~hich taught adding ve~y small amounts of powdered neat ZS~-5 catalyst, characterized by a particle si~e less than 5 microns.
s This patent taught that adding as little as 0.25 w* % ZSM-5 powder to the circulating catalyst inventory in an FCC unit would increase dry gas production by 50% (fro~ 3.9 wt % dry gas to 6.0 - see Example 6 in Table 2).
To summarize the state of the art regards addition of ~SM-5 to cracking catalyst, the following general statements can be made.
ZSM-5 is exceedingly active, and addition of even small amounts results in grea~ly augmented production of dry gas, at the expense of gasoline yield.
So far as is known to applicants, no use has been made on a commercial or long term scale of ZSM-5 in moving bed catalytic cracking processes.
Experimental work has shown that ZSM-5 catalyst, in FCC
; processes, loses activity relatively quickly. ZSM-5 is disproportionately active, compared to conventional PCC catalyst, from startup up to perhaps as much as a week of operation. After more than about a week of operation in an FCC unit, and after being subjected to repeated fluidized bed regenerations, in laboratory or in commercial units, the ZSM-5 activity becomes much harder to find.
~` These factors, high initial activity of ZSM-5, coupled with rapid deactivation of ZSM-5, discouraged researchers fro~ adding ZSM-5 to moving bed catalytic cracking units. The high startup activity of ZSM-5 results in voluminous production of light gases, which production is difficult to accommodate in downstream processing units designed to handle the product mix obtained from conventional catalyst. The rapid deactivation of ZSM 5 meant that its effect would soon be lost, requiring very expensive turnover of catalyst in the unit.
The problem of accommodating the initial high activity of ZSM-5 catalyst, has been solvedl and is discussed hereafter.
~2~5~5 P-2909 ` ~ 3 -The expected rapid catalyst deactivation~ based on projections of work using ZSM-5 catalyst in FCC units, did not occur in TCC units.
The properties of the ZSM-5 catalyst changed after repeated regenerations in a moving bed cracking unit.
It was expected that the catalys~ would lose activity. It did, but not nearly to the same extent as it did in conventional FCC
catalyst regenerations.
Surprisingly, the ZSM-5 catalyst changed during use, and behaved differently than it ever had before. It did not just get older, it got better.
As the feeds are substantially the same in FCC and TCC, it is postulated that the different reaction/regeneration me~hods used in these processes might be the cause of the change in the ZSM-5 catalyst.
~here is a difference in the severity and frequency of catalyst regeneration in TCC and FCC units.
FCC catalyst is frequently regenerated at temperatures of 650-732~C (1200-1350F) in a fluidized bed regenerator. Any hydrogen, or hydrocarbon, present on the catalyst burns to produce water. The water, or steam, deactivates the ZSM-5 catalyst fairly rapidly.
In contrast, in Thermofor catalytic cracking regeneration, the catalyst is regenerated in a moving bed. Hydrogen and hydrocarbon tend to be burned off the catalyst and swept away from it before coke on the catalyst is burned, and before very high tenperatures necessary to burn off coke are reached. In TCC regeneration the catalyst does not see water vapor for a very long time, and when it does see water vapor the catalyst is not very hot so the steaning deactivation effect is not so severe as in FCC.
Even making adjustments for the severity and frequency of FCC
regenerations vs. TCC regenerations, the ZSM-5 catalyst after regeneration in a TCC unit behaved differently than ZSM-5 catalyst regenerated in an FCC unit.
After many days of operation in a TCC unit, the Z~M-5 catalyst became a better catalyst. Some activity was lost, but significant and unexpected amounts of catalytic activity remained. Most significant, the aged, TCC regenerated ZSM-5 catalyst retained most of the virtues ~ 2~
F-29~9 - 4 -expected of ZSM-5 catalyst ~increased product octans number), while shedding most of the defects of ZSM-5 catalyst (loss in gasoline yield, increased dry gas make).
Accordingly, the present invention provides a crystalline material having the crystal structure of ZSM-5 which, when in contact with long chain relatively low octane olefins, at hydrocarbon conversion conditions sufficient to convert at least a portion of the olefins, exhibits as a primary conversion mechanism the isomerization of the long chain olefins to higher octane number materials.
In another embodimen~, the present invention provides a catalytic cracking process operating in the absence of additional hydrogen, wherein hydrocarbon feedstock is contacted with a catalyst and the feedstock is cracked to lighter products, characterized by adding a crystalline material having the crystal structure of ZSM-5 and having a reduced paraffin cracking activity, and exhibiting substantial olefin isomerization activity, as compared to conventional ZSM-5 catalyst.
In yet another embodiment, the present invention provides modified ZSM-5 catalyst characterized by its method of preparation comprising contacting hydrocarbons with ZSM-5 catalyst initially having substantial initial paraffin cracking ac~ivity in a catalytic cracking zone to produce coked catalyst containing minor amounts of hydrocarbon and coke regenerating the coked catalyst in catalyst regeneration zone by the steps comprising burning a majority of the hydrocarbon from the catalyst, while leaving a majority of the coke on the catalyst removing most of the products of hydrocarbon combustion fron contact with the catalyst and subsequently burning coke from the catalyst to produce a regenerated catalyst repeating steps a) and b) until the initial paraffin cracking ability of the ZSM-5 catalyst has been reduced by at least 50%~
ZSM-5 is described in U.S. Patent Nos. 3,702,886 and Re 29,948.
.
.
~24~S~5 F-Z9~9 : 5 -Quite a lot of work has been done on making material with a ZSM-5 crystal structure, but with different materials, ranging from all silica to materials containing silica and some o~her tetravalent metal such as boron, iron, gallium, etc.
As used herein, the term ZSM-5 refers to a material which has substantially the same crystal struc~ure as shown in U.S. Patent No.
3,702,886. Substitution of different cations, or changing the silicajalumina, or silica/boron ratio, may result in minor modifications of the X-ray diffraction patterns of the crystalline material so produced, but it is still ZSM-5, and contemplated for use herein.
MOVING BED CATALYTIC CRACKING
This process was introduced in the early 1940's and a detailed description thereof is not believed necessary.
Brie1y, the prccess uses a moving bed of catalytic cracking catalyst. Catalyst moves from the catalytic cracking reactor to a moving bed regenerator, and from there back to the reactor.
The oil chargestock to the process, usually without added hydrogen, is passed over the moving bed of catalyst and is catalytically cracked tu lighter products. During catalytic cracking, the catalyst is deactivated by coke deposition. Coke deposition is removed from the catalyst in a moving bed regenerator associated with the moving bed cracking unit.
MOVING BED REGENERATI~N
_ Moving bed catalytic cracking units have moving bed catalyst regeneration units associated therewith. The catalyst is generally maintained as a downflowing moving bed of catalyst. The catalyst may be disposed as an annular bed, with radial in or out gas flow. The moving catalyst bed may have the cross-section of a circle or a rectangle with gas flow from the lower portion of the catalyst bed to the upper, or the reverse. Alternatively5 gas flow may be across the moving bed of catalyst, or some combination of cross-flow, downflow and upflow.
3L2~iS25 F-2909 : 6 -It is preferred to have a moving bed of catalyst going down,with gas flow generally in an upward direction.
Although the catalyst from the moving bed catalytic cracking unit is usually stripped before being sent to the regenerator, there S is usually a small amount of hydrocarbon, and hydrog~n containing coke, contained on the catalyst. m is material is relatively easy to burn, and is usually burned from the catalyst in the top 5-10% of the moving bed catalyst regeneration unit. Usually-more severe conditions are necessary to completely remove the more refractive, relatively hydrogen free coke that remains on the catalyst after hydrocarbons are burned off, so progressively more severe operating conditions are experienced in the lower portions of the moving bed. These conditions may be in the form of increased temperature, increased oxygen concentration~ or both.
Much, if not all, of the heat required for catalyst regeneration is obtained by burning coke, and to a lesser extent, the light hydrocarbons that happen to be present on the catalyst. For start-up, or to adjust temperatures in the regenerator, an air preheater may be used. It is also possible to provide various heat exchange arrangements, e.g., incoming cool gas against hot exhaust gases, using hot exhaust gases to preheat catalyst, using hot regenerated catalyst as a source of incoming cool regeneration gas, etc. The conditions used in the moving bed catalyst regeneration units are highly conventional -- whatever temperatures, pressures, oxygen partial pressures have been found satisfactory in the past are believed to be satisfactory for use in the present invention.
In very general terms~ regeneration conditions in the moving bed regeneration should be adjusted so that at least half of the H20 precursors are burned off and at least the top half of the bed, and preferably in the top 5-10% of the moving bed o catalyst in the catalyst regeneration zone. Conditions should not be severe enough to remove more than 50% of the coke from the catalyst in the top one half of the moving bed regeneration zone, and prefsrably 60 to 90% of the coke remains on the catalyst after the H20 precursors have been burned away.
~2~2S
F-29~9 ~ 7 ~
Suitable regeneration conditions inclu~e temperatures of about 204-760C (400-1400F), preferably 427-649C (800-1200~F).
Regeneration pressure may range from subatmospheric to 10 atmospheres or higher if desired. Usually regeneration is conducted at pressures slightly above atmospheric. Oxygen concentration may range from about 1/2 mole % oxygen to the oxygen content of air, or even higher if desired. Very high oxygen concentrations should be avoided as ~hey lead to high cataIyst regeneration temperatures which tend to deactivate the catalyst. Regeneration with 1 to 20 mole %
oxygen is preferred~
No way is known today to duplicate this regeneration procedure in existing FCC units, although it may be possible to modify FCC
regeneration procedures to achieve this, i.e., staged regeneration where most of the water precursors are burned off at low temperatures, before coke combustion.
It is believed that other methods will be developed to quickly produce ZSM-5 with the properties obtainable now only after weeks and months of aging and regeneration in a moving bed catalytic cracking unit.
GATALYST PREPARATION ~Y REGæNeRA~IOn Modified ZSM-5 cataIyst can be obtained by periodically replacing some of the circulating inventory of ~oving bed catalytic cracking catalyst, and processing the catalyst to recover the ZSM-5 catalyst, or simply using the extrudate catalyst (with or without additional modifiers, hydrogenation/ dehydrogenation co~ponents) for the desired catalytic use.
Preferably the aged ZSM-5 catalyst is obtained downstream of the moving bed catalyst regeneration process, where it is essentially coke free. It is also acceptable to obtain the ZSM-5 containing catalyst downstream of the reactor and upstream of the moving bed regeneration zone. If this is done, because of the presence of relatively large amounts of coke on the catalyst in such circumstance, it will usually be necessary to subject the catalyst to conventional regeneration techniques prior to use.
~ 2~ 5 If TGC units are run to produce improved ZSM-5 catalyst, rather than improve TCC operati~n, some modifications to T~C operation may be perrnitted. Reiatively high concentrations of ZSM-5 may be added, e.g., 10 to 100%, preferably 20 to 80, wt ~ ZSM-5 catalyst content may be used. The 7SM-5 catalyst added ~ay have a smaller or larger particle size than the conventional catalyst, or a dlfferent L/D. The binder, or amorphous material used to give the catalyst strength and attrition resistance may be modified to optimize end use of the catalyst in some process other than TCC. Thus the binder may be inert, or all alumina, or some o~her material compatible with future catalytic use of the modified Z5M-5.
HYDROGARBON OONVERSION PROCESS~S
The ZSM-5 catalyst produced by the method of the present invention may continue to be used in moving bed catalytic cracking units with very good results.
The catalyst may also be used in any other hydrocarbon conversion process using catalyst. The ZSM-5 catalyst should be especially useful in-catalytic dewaxing processes designed to r~duce the pour point of fuel oils, or reduce the ~ax content of lubricating oil base stock.
The ZSM-5 catalyst of the present invention will also be very useful in hydrocracking, though in such service it is usually preferred to add a conventional hydrogenation/ dehydrogenation component.
HYDROGENATION/DEHYDROGENATION QOMPONENTS
Any of the conventional hydrogenation/dehydrogenation ; components heretofore added to zeolite or amorphous catalyst can be ~added to the ZSM-5 catalyst produced by the method of the present invention.
Suitable hydrogenation/dehydrogenation components include noble and base metals. Especially preferred among the noble metals are the Group VIII noble metals, especially platinum, palladium, and irridium. The noble metals may be present in an amount equal to 0.01 2~;i .. , . ~
to lO wt %, preferably O.l to 2 wt %, of the finished catalyst, on an elemental metal basis.
Base metal promoters may be used instead of noble metal promoters, or in conjunction with noble metal promoters. Base metal promoters consist of one or more elements selected from the metals of Group rVA and the base metals of Group VIII. Especially preferred are nickel, molybdenum, tungsten, nickel-moly, cobalt, and cobalt-moly.
Base metal promoters may be present in an amount e~ual to l to 25 wt ~, and preferably 4 to 20 wt %, of the finished catalyst, calculated on an elemental metal basis.
ZSM-5 catalyst which has been modified by the process of the present invention is indistinguishable by any known X-ray or elemental analysis from conventional ZSM-5 catalyst.
Using the guidelines discussed hereafter, it is possible to take a ZSM-5 catalyst, and determine if it has been modified as disclosed in the present invention.
Conventional ZSM-S catalyst, when added to conventional FCC
catalyst, usually gives about 2 octane no. gain/l LV ~ yield loss. In contrast, modified ZSM-5 catalyst of the present invention can give an octane no. gain with little or no yield loss. Conventional ZSM-5 catalyst results in significantly increased dry gas productionJ while this is not seen with the modified ZSM-5 catalyst of the present invention.
The modified ZSM-5 catalyst behaves differently from conventional ZSM-5 catalyst. Much of the ZSM-5's cracking activity is diminished, leading to reduced gas make and increased yield, at least in FCC units. It is believed that some paraffin cracking activity is lost.
Olefin isomerization activity is believed to be present. It is not exactly understood why ZSM-5 begins to exhibit olefin isomerization activity as it ages.
.
~2~iS;~5 EX~PLE 1 , This process was tested in a commercial size TCC unit.
Operating conditions are shown below:
Fresh Feed Rate,m3/S 2.45 x 10-2 Fresh Peed Rate, BPD 13,400 Recycle O
Catalyst Circulation, tons/hr 397 Catalyst Circulation, metric tons/hr 360 Catalyst/Oil 4.44 wt/wt Reactor Vapor Outlet Temp. 903F/484C
Catalyst Activity (CAT-~) 53.8 This unit had a 315 metric ton (347 ton) catalyst inventory.
The conventional catalyst in the unit had the following specifications.
.
::
, ' ;
Durabead lOA
.
Wt ~ REY ~ 12.~%
Bead Diameter 0.36-0.70 cm - The changeover catalyst had the following properties:
Wt % ZSN-5 5%
Wt % REY 7 5%
Bead Diameter 0.36-0.70 cm ~lring normal operation, this unit required makeup catalyst rates of 1.13 metric tons (1.25 tons) per day. The makeup catalyst rate is set to satisfy those catalys~ losses due to attrition, and also to maintain catalyst activity.
Catalyst addition was usually maintained at 1.8 metric tons (2 tons) per day, although there were short pericds of addition rates as high as 3.6 metric tons ~4 tons) per day.
Results of the test are reported hereafter in Table 1.
Feed properties are reported hereafter. The numbers reported are approximate because the feed was a blend of different crudes, and the blend varied somewhat.
!.
i lZ~S~i : Feed Properties Test Results Test Test MethodResults ..
Pour Point, C/F D 97 29/85 Carbon Residue Conradson D 189 0.31 Kinematic Viscosity 40C D 445-3 40.55 Kinematic Viscosity 100C D 445-5 5.922 : AniIine Point D 611 164.5 Bromine No. D1159 6.8 ~ 10 Refractive Index Liquids D1218-9 1.49000 : API Gravity D129B-3 23.0 Density, g/cc 0.916 Molecular Weig~t 353 Sulfur by XRFJ 0.002-5% 1.65 : 15 Hydrogen-Micro Pregl. 12.37 Nickel by AA 0.25 ppm Vanadium by AA 0.70 ppm Iron by AA ~.15 ppm Copper by AA 0.10 ppm Sodium by AA 2.95 ppm Nitrogen-Microdumas .16%
; REDU~ED PRESSURE DISTILLATION, D1160 ~ % (~ol) Over -C/CF @ 760 mm , ~25 5 324/615 ~:~ 30 399/75 446/8~5 : 35 95 528/983 :
` NOTE: IBP = Initial Boiling Point EP = End Point , . .
s~s _~ ~ O ~ C~
~ +++++I+~
~o n~
~o ~ ~ o ~ U~
a) ~3 ,i o ,i ~ ~ o ~ ~ + + ~ + ~ ~ + +
r~ r~ --i ,_, ~
,, ~ ~ ,, ~ C' Co"
I ~ ~ o o ,~ oo ~ CO
~1 ~ t~
~ ~ ~ o ~ J u~O cr~
o ~ '`
o, ~ ~ o ~ ~ ,S
O o o ~ ~ ~ ~ r~ ~ ~ o~ ~ r~
: ::: :: :: : :
: ~ ~ U) : 0 ~ ~ .,1 ~
~ tA ~ O
~ ~ ~ ~ ~ & ~ ~ ~
~ ~ ~ U ~ d~ o ~ ~ ~
U) ~ ::5 : ~ O o ~ g ~ ~ ~ Q) O
o ~ o ~ ^b .~ ~ $ ~ ~ o .
~ .
. .
.
s~ .
The circulating catalyst had, on average, slightly less than 2.5 wt % ZSM-5. Although roughly half the catalyst inventory had been dumped~ incrementally, and replaced with changeover catalyst which was rich in ZSM-5, so~e of the catalyst that was dumped had ZSM-5 in it from previous additions.
Conventional catalyst addition continued after a 2.5 wt ~ ZSM-5 level had been obtained. This was primarily to make up for normal attrition losses. This catalyst addition averaged roughly about 0.5 per day of catalyst inventory. This make-up catalyst added had no ZSM-5 added. The reason for this was that no more ZSM-5 containing catalyst happened to be available at that site.
Example 2 - Laboratory E aluation A laboratory test was conducted using a ZSM-5 catalyst in a standard laboratory test apparatus designed to simulate a moving bed cracking operation.
Feedstock Properties The feedstock was a gas oil fraction having the approximate properties reported earlier.
~hangeover Catalyst The changeover catalyst used in the laboratory test was essentially the same as the changeover catalyst used in the commercial test.
The catalyst addition scheme used was designed to rapidly bring the ZSM-5 content of the circulating or equilibrium catalyst to the desired level well before 72 days of operation~
` ~Z~S2~;
.. , , ~
C~
,~ ~ OD 1` ~ .~
~1 I O C: O ~ ~ O
~ . ' + + + + +
U~ o o~ ~ o _I
o _i ~ ~ ~ ~ ~i ~1 [` d 1` ~I r~ O
,~ I I o ~ ol +
~ ~ o ,1 U~
o o ; : ' : ~ :
o ~ ~ ~ ~ ~ U~
U~ ~
o ~ o Ct~ 7 ~1 ~ O u~
~ ~
o ~ ,~ o ~ o I ~ o : :
o ~ ~ ~+
X
:
~ ~l .r ~:: ~ ~ ~
h ~ --I 3 i "
~: :: : :
" i `. . ~Z~2S
A POSSIBLE EXPLANATION - OLEFIN ISOMERIZATION
It is believed that this modified ZSM-5 catalyst has acquired - the ability to isomerize olefins. The theory can be stated as follows:
In order to fully explain these test results the chemistry of octane enhancement being promoted by the ZSM-5 catalyst must first be understood. ZSM-5 increàses gasoline octane in catalytic cracking by cracking linear low octane components in the heavy end of the gasoline to lighter and more branched components. Such a mechanism is adequate to explain the performance during the addition of fresh ZSM-5 catalyst.
Nevertheless we must also consider the residual octane enhancement observed after fresh catalyst addition has been ended. Based upon gasoline compositional data obtained independent of this commercial test ZSM-5 is now known to isomerize low octane linear olefins to more highly branched and higher octane olefins.
We believe the activity enhancement catalyzed by fresh ZSM-5 catalyst addition is dominated by the first reaction, paraffin cracking. As the catalyst a~es in the unit and equilibrates the latter reaction mechanism, olefin isomerization, dominates as the cracking activity decreases, hence the residual octane enhancement activity observed.
Our test on a commercially sized unit of ZSM-5 addition gave initial octane gains (3.5-4.5 RON+O and 2.0-2.5 MONfO) with corresponding gasoline losses of 2.0-2.5% vol and C3 I C4 increases of 3.0-4.0% vol. Thère were no substantial increases in coke make observed. The increase in C3 I C4 together with additional outside i-C4 can be translated into increases in alkylate yield of 3.0-3.5% vol. The octane enhancement decayed at a relatively slow rate after ZSM-S addition has been terminated indicating that ZSM-5 octane enhancement shifted from paraffin cracking to olefin isomerization. The cracking of low octane components in the heavy gasoline end is dominant with fresh catalyst while olefin isomerization dominates as the catalyst ages in the TCC units.
~ 3~2~652~ii If we wanted to improve the operation of a moving bed catalyticcracking unit by the addition of ZSM-5 to it, we would replace 1-2%
per day of the circulating catalyst inventory with a ZSM-5 rich catalyst containing 1-10 wt ~ ZSM-5. ZSM-5 catalyst addition would continue until the circulating catalyst inventory contained the desired ZSM-5 content.
To obtain modified ZSM-5 catalyst for use in other units, we would add a ZSM-5 makeup catalyst that had much higher levels of ZSM-5, typically 10 to 100 wt ~, preferably 20-50 wt ~ ZSM-5. This may not be the optimal addition scheme as far as the moving bed catalytic cracking unit is concerned, but it would be the best way of making modified ZSM-5 catalyst in a moving bed cracking unit that had to keep running.
The ZSM-5 rich catalyst added to a TCC may be made with a slightly different particle size, or L/D, or geometry, permitting eventual separation and recovery of modified ZSM-5 catalyst from circulating catalyst inventory.
,, , ~:
:
~ :
, ,
MOVING BED CATALYTIC CRACKING
This process was introduced in the early 1940's and a detailed description thereof is not believed necessary.
Brie1y, the prccess uses a moving bed of catalytic cracking catalyst. Catalyst moves from the catalytic cracking reactor to a moving bed regenerator, and from there back to the reactor.
The oil chargestock to the process, usually without added hydrogen, is passed over the moving bed of catalyst and is catalytically cracked tu lighter products. During catalytic cracking, the catalyst is deactivated by coke deposition. Coke deposition is removed from the catalyst in a moving bed regenerator associated with the moving bed cracking unit.
MOVING BED REGENERATI~N
_ Moving bed catalytic cracking units have moving bed catalyst regeneration units associated therewith. The catalyst is generally maintained as a downflowing moving bed of catalyst. The catalyst may be disposed as an annular bed, with radial in or out gas flow. The moving catalyst bed may have the cross-section of a circle or a rectangle with gas flow from the lower portion of the catalyst bed to the upper, or the reverse. Alternatively5 gas flow may be across the moving bed of catalyst, or some combination of cross-flow, downflow and upflow.
3L2~iS25 F-2909 : 6 -It is preferred to have a moving bed of catalyst going down,with gas flow generally in an upward direction.
Although the catalyst from the moving bed catalytic cracking unit is usually stripped before being sent to the regenerator, there S is usually a small amount of hydrocarbon, and hydrog~n containing coke, contained on the catalyst. m is material is relatively easy to burn, and is usually burned from the catalyst in the top 5-10% of the moving bed catalyst regeneration unit. Usually-more severe conditions are necessary to completely remove the more refractive, relatively hydrogen free coke that remains on the catalyst after hydrocarbons are burned off, so progressively more severe operating conditions are experienced in the lower portions of the moving bed. These conditions may be in the form of increased temperature, increased oxygen concentration~ or both.
Much, if not all, of the heat required for catalyst regeneration is obtained by burning coke, and to a lesser extent, the light hydrocarbons that happen to be present on the catalyst. For start-up, or to adjust temperatures in the regenerator, an air preheater may be used. It is also possible to provide various heat exchange arrangements, e.g., incoming cool gas against hot exhaust gases, using hot exhaust gases to preheat catalyst, using hot regenerated catalyst as a source of incoming cool regeneration gas, etc. The conditions used in the moving bed catalyst regeneration units are highly conventional -- whatever temperatures, pressures, oxygen partial pressures have been found satisfactory in the past are believed to be satisfactory for use in the present invention.
In very general terms~ regeneration conditions in the moving bed regeneration should be adjusted so that at least half of the H20 precursors are burned off and at least the top half of the bed, and preferably in the top 5-10% of the moving bed o catalyst in the catalyst regeneration zone. Conditions should not be severe enough to remove more than 50% of the coke from the catalyst in the top one half of the moving bed regeneration zone, and prefsrably 60 to 90% of the coke remains on the catalyst after the H20 precursors have been burned away.
~2~2S
F-29~9 ~ 7 ~
Suitable regeneration conditions inclu~e temperatures of about 204-760C (400-1400F), preferably 427-649C (800-1200~F).
Regeneration pressure may range from subatmospheric to 10 atmospheres or higher if desired. Usually regeneration is conducted at pressures slightly above atmospheric. Oxygen concentration may range from about 1/2 mole % oxygen to the oxygen content of air, or even higher if desired. Very high oxygen concentrations should be avoided as ~hey lead to high cataIyst regeneration temperatures which tend to deactivate the catalyst. Regeneration with 1 to 20 mole %
oxygen is preferred~
No way is known today to duplicate this regeneration procedure in existing FCC units, although it may be possible to modify FCC
regeneration procedures to achieve this, i.e., staged regeneration where most of the water precursors are burned off at low temperatures, before coke combustion.
It is believed that other methods will be developed to quickly produce ZSM-5 with the properties obtainable now only after weeks and months of aging and regeneration in a moving bed catalytic cracking unit.
GATALYST PREPARATION ~Y REGæNeRA~IOn Modified ZSM-5 cataIyst can be obtained by periodically replacing some of the circulating inventory of ~oving bed catalytic cracking catalyst, and processing the catalyst to recover the ZSM-5 catalyst, or simply using the extrudate catalyst (with or without additional modifiers, hydrogenation/ dehydrogenation co~ponents) for the desired catalytic use.
Preferably the aged ZSM-5 catalyst is obtained downstream of the moving bed catalyst regeneration process, where it is essentially coke free. It is also acceptable to obtain the ZSM-5 containing catalyst downstream of the reactor and upstream of the moving bed regeneration zone. If this is done, because of the presence of relatively large amounts of coke on the catalyst in such circumstance, it will usually be necessary to subject the catalyst to conventional regeneration techniques prior to use.
~ 2~ 5 If TGC units are run to produce improved ZSM-5 catalyst, rather than improve TCC operati~n, some modifications to T~C operation may be perrnitted. Reiatively high concentrations of ZSM-5 may be added, e.g., 10 to 100%, preferably 20 to 80, wt ~ ZSM-5 catalyst content may be used. The 7SM-5 catalyst added ~ay have a smaller or larger particle size than the conventional catalyst, or a dlfferent L/D. The binder, or amorphous material used to give the catalyst strength and attrition resistance may be modified to optimize end use of the catalyst in some process other than TCC. Thus the binder may be inert, or all alumina, or some o~her material compatible with future catalytic use of the modified Z5M-5.
HYDROGARBON OONVERSION PROCESS~S
The ZSM-5 catalyst produced by the method of the present invention may continue to be used in moving bed catalytic cracking units with very good results.
The catalyst may also be used in any other hydrocarbon conversion process using catalyst. The ZSM-5 catalyst should be especially useful in-catalytic dewaxing processes designed to r~duce the pour point of fuel oils, or reduce the ~ax content of lubricating oil base stock.
The ZSM-5 catalyst of the present invention will also be very useful in hydrocracking, though in such service it is usually preferred to add a conventional hydrogenation/ dehydrogenation component.
HYDROGENATION/DEHYDROGENATION QOMPONENTS
Any of the conventional hydrogenation/dehydrogenation ; components heretofore added to zeolite or amorphous catalyst can be ~added to the ZSM-5 catalyst produced by the method of the present invention.
Suitable hydrogenation/dehydrogenation components include noble and base metals. Especially preferred among the noble metals are the Group VIII noble metals, especially platinum, palladium, and irridium. The noble metals may be present in an amount equal to 0.01 2~;i .. , . ~
to lO wt %, preferably O.l to 2 wt %, of the finished catalyst, on an elemental metal basis.
Base metal promoters may be used instead of noble metal promoters, or in conjunction with noble metal promoters. Base metal promoters consist of one or more elements selected from the metals of Group rVA and the base metals of Group VIII. Especially preferred are nickel, molybdenum, tungsten, nickel-moly, cobalt, and cobalt-moly.
Base metal promoters may be present in an amount e~ual to l to 25 wt ~, and preferably 4 to 20 wt %, of the finished catalyst, calculated on an elemental metal basis.
ZSM-5 catalyst which has been modified by the process of the present invention is indistinguishable by any known X-ray or elemental analysis from conventional ZSM-5 catalyst.
Using the guidelines discussed hereafter, it is possible to take a ZSM-5 catalyst, and determine if it has been modified as disclosed in the present invention.
Conventional ZSM-S catalyst, when added to conventional FCC
catalyst, usually gives about 2 octane no. gain/l LV ~ yield loss. In contrast, modified ZSM-5 catalyst of the present invention can give an octane no. gain with little or no yield loss. Conventional ZSM-5 catalyst results in significantly increased dry gas productionJ while this is not seen with the modified ZSM-5 catalyst of the present invention.
The modified ZSM-5 catalyst behaves differently from conventional ZSM-5 catalyst. Much of the ZSM-5's cracking activity is diminished, leading to reduced gas make and increased yield, at least in FCC units. It is believed that some paraffin cracking activity is lost.
Olefin isomerization activity is believed to be present. It is not exactly understood why ZSM-5 begins to exhibit olefin isomerization activity as it ages.
.
~2~iS;~5 EX~PLE 1 , This process was tested in a commercial size TCC unit.
Operating conditions are shown below:
Fresh Feed Rate,m3/S 2.45 x 10-2 Fresh Peed Rate, BPD 13,400 Recycle O
Catalyst Circulation, tons/hr 397 Catalyst Circulation, metric tons/hr 360 Catalyst/Oil 4.44 wt/wt Reactor Vapor Outlet Temp. 903F/484C
Catalyst Activity (CAT-~) 53.8 This unit had a 315 metric ton (347 ton) catalyst inventory.
The conventional catalyst in the unit had the following specifications.
.
::
, ' ;
Durabead lOA
.
Wt ~ REY ~ 12.~%
Bead Diameter 0.36-0.70 cm - The changeover catalyst had the following properties:
Wt % ZSN-5 5%
Wt % REY 7 5%
Bead Diameter 0.36-0.70 cm ~lring normal operation, this unit required makeup catalyst rates of 1.13 metric tons (1.25 tons) per day. The makeup catalyst rate is set to satisfy those catalys~ losses due to attrition, and also to maintain catalyst activity.
Catalyst addition was usually maintained at 1.8 metric tons (2 tons) per day, although there were short pericds of addition rates as high as 3.6 metric tons ~4 tons) per day.
Results of the test are reported hereafter in Table 1.
Feed properties are reported hereafter. The numbers reported are approximate because the feed was a blend of different crudes, and the blend varied somewhat.
!.
i lZ~S~i : Feed Properties Test Results Test Test MethodResults ..
Pour Point, C/F D 97 29/85 Carbon Residue Conradson D 189 0.31 Kinematic Viscosity 40C D 445-3 40.55 Kinematic Viscosity 100C D 445-5 5.922 : AniIine Point D 611 164.5 Bromine No. D1159 6.8 ~ 10 Refractive Index Liquids D1218-9 1.49000 : API Gravity D129B-3 23.0 Density, g/cc 0.916 Molecular Weig~t 353 Sulfur by XRFJ 0.002-5% 1.65 : 15 Hydrogen-Micro Pregl. 12.37 Nickel by AA 0.25 ppm Vanadium by AA 0.70 ppm Iron by AA ~.15 ppm Copper by AA 0.10 ppm Sodium by AA 2.95 ppm Nitrogen-Microdumas .16%
; REDU~ED PRESSURE DISTILLATION, D1160 ~ % (~ol) Over -C/CF @ 760 mm , ~25 5 324/615 ~:~ 30 399/75 446/8~5 : 35 95 528/983 :
` NOTE: IBP = Initial Boiling Point EP = End Point , . .
s~s _~ ~ O ~ C~
~ +++++I+~
~o n~
~o ~ ~ o ~ U~
a) ~3 ,i o ,i ~ ~ o ~ ~ + + ~ + ~ ~ + +
r~ r~ --i ,_, ~
,, ~ ~ ,, ~ C' Co"
I ~ ~ o o ,~ oo ~ CO
~1 ~ t~
~ ~ ~ o ~ J u~O cr~
o ~ '`
o, ~ ~ o ~ ~ ,S
O o o ~ ~ ~ ~ r~ ~ ~ o~ ~ r~
: ::: :: :: : :
: ~ ~ U) : 0 ~ ~ .,1 ~
~ tA ~ O
~ ~ ~ ~ ~ & ~ ~ ~
~ ~ ~ U ~ d~ o ~ ~ ~
U) ~ ::5 : ~ O o ~ g ~ ~ ~ Q) O
o ~ o ~ ^b .~ ~ $ ~ ~ o .
~ .
. .
.
s~ .
The circulating catalyst had, on average, slightly less than 2.5 wt % ZSM-5. Although roughly half the catalyst inventory had been dumped~ incrementally, and replaced with changeover catalyst which was rich in ZSM-5, so~e of the catalyst that was dumped had ZSM-5 in it from previous additions.
Conventional catalyst addition continued after a 2.5 wt ~ ZSM-5 level had been obtained. This was primarily to make up for normal attrition losses. This catalyst addition averaged roughly about 0.5 per day of catalyst inventory. This make-up catalyst added had no ZSM-5 added. The reason for this was that no more ZSM-5 containing catalyst happened to be available at that site.
Example 2 - Laboratory E aluation A laboratory test was conducted using a ZSM-5 catalyst in a standard laboratory test apparatus designed to simulate a moving bed cracking operation.
Feedstock Properties The feedstock was a gas oil fraction having the approximate properties reported earlier.
~hangeover Catalyst The changeover catalyst used in the laboratory test was essentially the same as the changeover catalyst used in the commercial test.
The catalyst addition scheme used was designed to rapidly bring the ZSM-5 content of the circulating or equilibrium catalyst to the desired level well before 72 days of operation~
` ~Z~S2~;
.. , , ~
C~
,~ ~ OD 1` ~ .~
~1 I O C: O ~ ~ O
~ . ' + + + + +
U~ o o~ ~ o _I
o _i ~ ~ ~ ~ ~i ~1 [` d 1` ~I r~ O
,~ I I o ~ ol +
~ ~ o ,1 U~
o o ; : ' : ~ :
o ~ ~ ~ ~ ~ U~
U~ ~
o ~ o Ct~ 7 ~1 ~ O u~
~ ~
o ~ ,~ o ~ o I ~ o : :
o ~ ~ ~+
X
:
~ ~l .r ~:: ~ ~ ~
h ~ --I 3 i "
~: :: : :
" i `. . ~Z~2S
A POSSIBLE EXPLANATION - OLEFIN ISOMERIZATION
It is believed that this modified ZSM-5 catalyst has acquired - the ability to isomerize olefins. The theory can be stated as follows:
In order to fully explain these test results the chemistry of octane enhancement being promoted by the ZSM-5 catalyst must first be understood. ZSM-5 increàses gasoline octane in catalytic cracking by cracking linear low octane components in the heavy end of the gasoline to lighter and more branched components. Such a mechanism is adequate to explain the performance during the addition of fresh ZSM-5 catalyst.
Nevertheless we must also consider the residual octane enhancement observed after fresh catalyst addition has been ended. Based upon gasoline compositional data obtained independent of this commercial test ZSM-5 is now known to isomerize low octane linear olefins to more highly branched and higher octane olefins.
We believe the activity enhancement catalyzed by fresh ZSM-5 catalyst addition is dominated by the first reaction, paraffin cracking. As the catalyst a~es in the unit and equilibrates the latter reaction mechanism, olefin isomerization, dominates as the cracking activity decreases, hence the residual octane enhancement activity observed.
Our test on a commercially sized unit of ZSM-5 addition gave initial octane gains (3.5-4.5 RON+O and 2.0-2.5 MONfO) with corresponding gasoline losses of 2.0-2.5% vol and C3 I C4 increases of 3.0-4.0% vol. Thère were no substantial increases in coke make observed. The increase in C3 I C4 together with additional outside i-C4 can be translated into increases in alkylate yield of 3.0-3.5% vol. The octane enhancement decayed at a relatively slow rate after ZSM-S addition has been terminated indicating that ZSM-5 octane enhancement shifted from paraffin cracking to olefin isomerization. The cracking of low octane components in the heavy gasoline end is dominant with fresh catalyst while olefin isomerization dominates as the catalyst ages in the TCC units.
~ 3~2~652~ii If we wanted to improve the operation of a moving bed catalyticcracking unit by the addition of ZSM-5 to it, we would replace 1-2%
per day of the circulating catalyst inventory with a ZSM-5 rich catalyst containing 1-10 wt ~ ZSM-5. ZSM-5 catalyst addition would continue until the circulating catalyst inventory contained the desired ZSM-5 content.
To obtain modified ZSM-5 catalyst for use in other units, we would add a ZSM-5 makeup catalyst that had much higher levels of ZSM-5, typically 10 to 100 wt ~, preferably 20-50 wt ~ ZSM-5. This may not be the optimal addition scheme as far as the moving bed catalytic cracking unit is concerned, but it would be the best way of making modified ZSM-5 catalyst in a moving bed cracking unit that had to keep running.
The ZSM-5 rich catalyst added to a TCC may be made with a slightly different particle size, or L/D, or geometry, permitting eventual separation and recovery of modified ZSM-5 catalyst from circulating catalyst inventory.
,, , ~:
:
~ :
, ,
Claims (7)
1. A crystalline material having the crystal structure of ZSM-5 which, when in contact with long chain relatively low octane olefins, at hydrocarbon conversion conditions sufficient to convert at least a portion of the olefins, exhibits as a primary conversion mechanism the isomerization of the long chain olefins to higher octane number materials, said crystalline material being obtained by the steps comprising:
a) contacting hydrocarbons with ZSM-5 catalyst initially having substantial initial paraffin cracking activity in the catalytic cracking zone to produce coked catalyst containing minor amounts of hydrocarbon and coke;
b) regenerating the coked catalyst in catalyst regeneration zone by the steps comprising:
(i) burning a majority of the hydrocarbon from the catalyst, while leaving a majority of the coke on the catalyst;
(ii) removing most of the products of hydrocarbon combustion from contact with the catalyst and subsequently;
(iii) burning coke from the catalyst to produce a regenerated catalyst.
c) repeating steps a) and b) until the initial paraffin cracking ability of the ZSM-5 catalyst has been reduced by at least 50%.
a) contacting hydrocarbons with ZSM-5 catalyst initially having substantial initial paraffin cracking activity in the catalytic cracking zone to produce coked catalyst containing minor amounts of hydrocarbon and coke;
b) regenerating the coked catalyst in catalyst regeneration zone by the steps comprising:
(i) burning a majority of the hydrocarbon from the catalyst, while leaving a majority of the coke on the catalyst;
(ii) removing most of the products of hydrocarbon combustion from contact with the catalyst and subsequently;
(iii) burning coke from the catalyst to produce a regenerated catalyst.
c) repeating steps a) and b) until the initial paraffin cracking ability of the ZSM-5 catalyst has been reduced by at least 50%.
2. Crystalline material of claim 1 characterized in that the ZSM-5 has been repeatedly regenerated in a moving bed catalyst regeneration zone.
3. Crystalline material of claim 1, in an amorphous support which also contains 1 to 30 wt% large pore zeolite.
4. Crystalline material of claim 1, in an amorphous support wherein the ZSM-5 comprises 1 to 10 wt% of the total weight thereof.
5. Crystalline material of claim 1, wherein the ZSM-5 comprises 10 to 100 wt% ZSM-5 in an amorphous binder.
6. Crystalline material of claim 1, wherein the ZSM-5 comprises about 20 to 50 wt% ZSM-5 and 80 to 50 wt%
amorphous binder.
amorphous binder.
7. In a catalytic cracking process operating in the absence of additional hydrogen, wherein hydrocarbon feedstock is contacted with a catalyst and the feedstock is cracked to lighter products, the improvement comprising contacting a hydrocarbon feedstock containing long chain relatively low octane olefins with the crystalline material as claimed in claim 1 to isomerize the low chain olefins to higher octane number materials.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US627,991 | 1984-07-05 | ||
| US62799184A | 1984-07-07 | 1984-07-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1246525A true CA1246525A (en) | 1988-12-13 |
Family
ID=24516967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000485132A Expired CA1246525A (en) | 1984-07-05 | 1985-06-25 | Modified zsm-5 catalyst, and method of preparation and use thereof |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS6182845A (en) |
| CA (1) | CA1246525A (en) |
| ZA (1) | ZA855105B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4798816A (en) * | 1986-12-19 | 1989-01-17 | Union Oil Company Of California | Process for increasing the selectivity of an alkylation catalyst for monoalkylation |
| EP0920911A1 (en) * | 1997-12-05 | 1999-06-09 | Fina Research S.A. | Production of catalysts for olefin conversion |
| JP4948863B2 (en) * | 2006-03-22 | 2012-06-06 | 一般財団法人石油エネルギー技術センター | Catalytic cracking catalyst, production method thereof, and catalytic cracking method of hydrocarbon oil |
-
1985
- 1985-06-25 CA CA000485132A patent/CA1246525A/en not_active Expired
- 1985-07-05 ZA ZA855105A patent/ZA855105B/en unknown
- 1985-07-05 JP JP14689585A patent/JPS6182845A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6182845A (en) | 1986-04-26 |
| ZA855105B (en) | 1987-02-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0081774B1 (en) | Rare earth containing y zeolite compositions | |
| US6835863B2 (en) | Catalytic production of light olefins from naphtha feed | |
| US6652737B2 (en) | Production of naphtha and light olefins | |
| US4565621A (en) | Hydrocracking with rare earth-containing Y zeolite compositions | |
| MXPA02000372A (en) | Catalytic production of light olefins rich in propylene. | |
| US4584287A (en) | Rare earth-containing Y zeolite compositions | |
| AU2001276996A1 (en) | Production of naphtha and light olefins | |
| JP3688476B2 (en) | Hydrocracking catalyst for medium distillate oil production | |
| EP0541994A1 (en) | A process for regenerating hydrocarbon oil hydrogenation catalysts | |
| US4382023A (en) | Catalyzed combustion in cracking catalyst | |
| US4604187A (en) | Hydrocracking with rare earth-containing Y zeolite compositions | |
| CA1246525A (en) | Modified zsm-5 catalyst, and method of preparation and use thereof | |
| JPH01213240A (en) | Production of hydrocarbon | |
| EP0167393A2 (en) | Modified zsm-5 catalyst, and method of preparation and use thereof | |
| US4316795A (en) | Hydrocarbon conversion process with reduced sulfur oxide emissions | |
| GB2075358A (en) | Stabilizing hydrofining catalysts | |
| EP0416010B1 (en) | Process for hydrotreating olefinic distillate | |
| US3216922A (en) | Hydrocarbon conversion catalysts and process for use of the same | |
| EP0167325A2 (en) | Method of adding ZSM-5 containing catalyst to moving bed catalytic cracking units | |
| US5151393A (en) | Staged process for reactivation of spent zeolite catalyst particles | |
| US4265787A (en) | Cracking catalyst | |
| US4252686A (en) | Catalyst and process for conversion of hydrocarbons | |
| CA1091638A (en) | Catalyst and process for conversion of hydrocarbons | |
| US4263172A (en) | Cracking catalysts | |
| US4325814A (en) | Catalytic cracking process utilizing a copper chromite oxidation catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |