CA1257245A - Rejuvenation of a deactivated catalyst - Google Patents
Rejuvenation of a deactivated catalystInfo
- Publication number
- CA1257245A CA1257245A CA000494758A CA494758A CA1257245A CA 1257245 A CA1257245 A CA 1257245A CA 000494758 A CA000494758 A CA 000494758A CA 494758 A CA494758 A CA 494758A CA 1257245 A CA1257245 A CA 1257245A
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- metal
- aqueous solution
- rejuvenating
- solution
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/20—Regeneration or reactivation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/90—Regeneration or reactivation
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Saccharide Compounds (AREA)
Abstract
-?-ABSTRACT OF THE DISCLOSURE
In one embodiment of the present invention, a sulfur-contaminated catalyst is rejuvenated by the cyclic process of (1) exposing the catalyst to oxidizing condi-tions in the presence of oxygen at a temperature of from 200°C to 450°C; (2) contacting the oxidized catalyst with at least 10 cc of an aqueous media in the liquid phase per cc of catalyst; wherein the aqueous media is selected from the group consisting of water, an aqueous solution, and a saturated water vapor; and (3) exposing said wet catalyst to reducing conditions in the presence of hydrogen at a temperature of from 200°C to 700°C. In another embodi-ment, the catalyst is contacted with an aqueous solution of a salt of a metal selected from the group consisting of an alkali metal and an alkaline earth metal. In still another embodiment, the catalyst is washed with either a neutral solution or an acidic solution, contacted with an aqueous solution of a salt of a metal selected from the group consisting of an alkali metal and an alkaline earth metal, washed with a neutral solution, and dried.
In one embodiment of the present invention, a sulfur-contaminated catalyst is rejuvenated by the cyclic process of (1) exposing the catalyst to oxidizing condi-tions in the presence of oxygen at a temperature of from 200°C to 450°C; (2) contacting the oxidized catalyst with at least 10 cc of an aqueous media in the liquid phase per cc of catalyst; wherein the aqueous media is selected from the group consisting of water, an aqueous solution, and a saturated water vapor; and (3) exposing said wet catalyst to reducing conditions in the presence of hydrogen at a temperature of from 200°C to 700°C. In another embodi-ment, the catalyst is contacted with an aqueous solution of a salt of a metal selected from the group consisting of an alkali metal and an alkaline earth metal. In still another embodiment, the catalyst is washed with either a neutral solution or an acidic solution, contacted with an aqueous solution of a salt of a metal selected from the group consisting of an alkali metal and an alkaline earth metal, washed with a neutral solution, and dried.
Description
~257245 REJUVENATION OF A DEACTIVATED CATALYST
BACKGROUNV OF THE INVENTION
The present invention concerns a method for re~uvenating a zeolitic catalyst.
Catalytic refonming is a well known process that 10 is used to raise the octane rating of a naphtha for gasoline. The reactions that occur during refonmin~
include: dehydrocyclization of acyclic hydrocarbons, dehydrogenation of cyclohexanes~ dehydroisomerization of alkylcyclopentanes, isomerization of paraffins, dealky-15 lation of alkylbenzenes, and hydrocracking of paraffins.The hydrocracking reaction should be suppressed because that reaction lowers the yield of hydrogen and lowers the yield of liquid products.
Reforming catalysts must be selective for dehydrocyclization in order to produce high yields of liguid product and low yields of light gases. These cata-lysts should possess good activity, so that low tempera-tures can be used in the reformer. Also they should possess good stability, so that they can maintain a high 25 activity and a high selectivity for dehydrocyclization over a long period of time. Furthermore, they should be Ir-regenerable, so that they can be regenerated without loss of performance.
While most reforming catalysts contain platinum .
on an alumina support, other catalyst supports have heen proposed, such as lar~e-pore zeolites. These large-pore zeolites have pores large enough for hydrocarbons in the gasoline boiling range to pass through. Catalysts based on these zeolitic supports have been commercially unsuc-cessful.
~ ecently, a new catalyst was developed thatcomprises: a large-pore zeolite, a Group VIII metal, and an alkaline earth metal. This catalyst has a very high selectivity for dehydrocyclization, but it is hard to regenerate.
.~
,~
~257245 SUMMARY OF THE INVENTION
05 The present invention is based on the discovery that a catalyst can be rejuvenated by contacting the cata- `
lyst with an a~ueous media selected from the group con-sisting of water, an aqueous solution, and a saturated water vapor. This method of rejuvenation works for 10 large-pore zeolitic catalysts that contain at least one Group VIII metal~
In a first embodiment, at least lO cc of aqueous media must be used per cc of catalyst, and the aqueous media must be in the li~uid phase. Preferabl~, at least 15 500 cc of aqueous media is used per cc of catalyst. Prior to contacting the catalyst with an aqueous media, it should be exposed to oxidizing conditions, preferably at a temperature of from about 200C to about 450C. After the catalyst is contacted with an aqueous media, it should be 20 exposed to reducin~ conditions, preferably in the presence of hydrogen at a temperature of from about 200C to about 700C. The steps of oxidizing the catalyst, contactin~
the catalyst with an aqueous media, and reducing the cata-lyst can be repeated as necessary, until the catalyst is rejuvenated to the desired level.
A basic solution (i.e., pH greater than 7) can 1 be used instead of water or a saturated water vapor. In this embodiment, the catalyst is contacted with a basic solution at a temperature of from about 70C to about 80C. The basic solution can be an alkali metal hydroxide solution, such as potassium hydroxide solution having a pH
of at least lO.
In a second embodiment, a zeolitic catalyst can be rejuvenated, and the stability of that catalyst can be improved, by contacting the catalyst with an aqueous solu-tion of a metal salt or metal hydroxide, wherein the metal is either an alkali metal and an alkaline earth metal.
In a third embodiment, a zeolitic catalyst can .;
be reiuvenated by washing the catalyst with either a 4~ neutral or an acidic solution/ contacting the washed cata- ~
lyst with an aqueous solution of a metal salt or metal ~' ~2572~5 ol hydroxide (the metal is either an al~ali metal and an alkaline earth metal), washing the contacted catalyst with a neutral solution; and drying the twice washed catalyst.
This method is useful for both sulfur-contaminated cata-lysts and catalysts deactivated by other means~
Preferably, in the second and third embodiments, the concentration of the aqueous solution should be from 0.1% to 10~ by weight of metal. A more preferred concen-tration range is from 0.1% to 8~ by weight of metal.
Preferably, there is from 2 to 30 cc of aqueous solution per gram of catalyst in each washing step.
Preferably, in the second and third embodiments, the metal salt or hydroxide is either a metal halide, metal nitrate, metal carbonate, metal phosphate, or metal hydroxide. The preferred metal salt is a metal hydroxide, such as potassium hydroxide.
~O Preferably, in the second and third embodiments, the contacting occurs at a temperature of from 25C to 100C (more preferably, about 80C), then the catalyst that has been contacted with the aqueous solution is washed with from 10 to 200 cc of water per gram of cata-lyst to remove excess metal, and the washed catalyst is dried. Preferably, the catalyst is contacted with an oxidizing gas at conditions which favor oxidation before the first washing step.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In its broadest aspect, the present invention involves rejuvenating a catalyst by contacting the cata-lyst with a large quantity of an aqueous media in the liquid phase. This contacting step is an essential ele-ment of the present invention.
The aqueous media must he in the liquid phase.
If water in the li~uid phase is not present then the con-tacting step does not show the surprising re~eneration of the present invention.
Also, a large quantity of aqueous media is required. At least lO cc of aqueous media should be used ~:2572~5 per cc of catalyst. Rreferably, at least 500 cc of 05 aqueous media should be used per cc of catalyst.
This regeneration procedure is not only useful for sulfur-contaminated catalysts, but is also useful for catalysts deactivated by other means. ! ' A basic solution can be used to contact the 10 sulfur-contaminated catalyst at a temperature of from about 70C to about 80C. Preferably, the basic solution is an alkali metal hydroxide solution, such as a potassium hydroxide solution having a pH of at least 10. This embo-diment has the advantaqe o minimizing the formation of 15 acid sites on the catalyst.
A saturated water vapor in the liquid phase can be used to contact the sulfur-contaminated catalyst, pre-ferably at a temperature of from about 120C to about 180C. This embodiment has the advantage of allowing in situ treatment without having to remove or handle the catalyst.
The present invention rejuvenates the catalyst without removing all the sulfur from the catalyst. While it is not fully understood how the present invention achieves its surprising rejuvenation of sulfur-contami-nated catalysts, one theory is ~hat the washing might be converting the sulfur present in the catalyst to a state which is easier to be removed from the catalyst during the reduction and reforming process or a state which does not _`
interfere with the desired catalytic reaction~.
The catalyst can be exposed to oxidizing condi-tions prior to contactinq the catalyst with an agueous media. While the contacting step causes a sizable rejuve-nation of the catalyst, the combination of the oxidizing step and the contacting step causes a still more sizable rejuvenation. Preferably, the oxidation step occurs in ~-the presence of oxygen at a temperature of from about 200C to about 450C. The oxidation step alone does not rejuvenate the catalyst.
It is thought that the oxidation step changes the sulfur to a water-soluble form and/or weakens the ~2S7Z~S
01 _5_ association between platinum and sulfur. This could be effected with other oxidizing agents besides oxygen, such S as KMnO4, CrO3, etc. This could be applied to other metal-containing catalysts where sulfur is known to harm activity.
The catalyst can be exposed to reducin~ condi-tions after contacting the catalyst with an aqueous media.
10 Preferably, the reduction step occurs in the presence o hydrogen at a temperature of from 200C to 700C. Note that no rejuvenatlon occurs from the reduction step alone, or from reduction following oxidation without including the water step.
The ef~ectiveness oE this reducing step may depend on whether the solvent molecules shielding the platinum are removed faster than the sulfur is reduced.
In this context, we have discovered that if the water treatment employs wet hydrogen, a more stable rejuvenated catalyst is obtained. Other reducing agents, such as water-soluble hydrazine-hydrate, NaBH4, and KBH4, could also be used for this step.
The combination of the oxidizing step, the soak-ing step, and the reducing step causes a still more sizable reiuvenation than the combination of the soaking step with either only the oxidizing step or only the reducing step. These three steps can be repeated, as needed, until the catalyst is rejuvenated to the desired level.
A sulfur-contaminated catalyst can be exposed to oxidizing conditions in the presence of oxygen at a tem-perature of from about 200C to about 450C, the oxidized catalyst is contacted with at least 500 cc of a saturated water vapor in the liquid phase per cc of catalyst at a temperature of from about 120C to about 180C, then the catalyst is exposed to reducing conditions in the presence of hydrogen at a temperature of from 200C to about 700C.
These steps are repeated until the catalyst is rejuvenated to the desired level.
'10 ~572~5 In a second embodiment, a large-pore zeolitic catalyst that contains at least one Group VIII metal is rejuvenated by contactin~ the catalyst with an aqueous solution of a salt of a metal selected from the 0roup consisting of an alkali metal and an alkaline earth metal.
An essential step of this embodiment is that the 10 catalyst must be contacted with an aqueous solution of a salt or hydroxide of a metal selected from the group con-sisting of an alkali metal and an alkaline earth metal.
The metal salt or hydroxide may be either a metal halide, -metal nitrate, metal carbonate, metal phosphate, or metal 15 hydroxide. Preferably, the metal salt or hydroxide is potassium hydroxide. Preferably, the catalyst is con-tacted with from 2 to 30 cc of aqueous solution per gram of catalyst at a temperature of from 25C to 100C, more preferably at a temperature of about 80C. The aqueous solution should have a concentration of from 0.1~ to 10%
by weight of metal, preferably from 1% to 8% by weight of metal.
After the catalyst has been contacted with the aqueous solution, the catalyst is washed with ~rom 10 to 200 cc of water per gram of catalyst to remove excess metal, then the washed catalyst is dried. , r The sulfur-contaminated catalyst can comprise a type L zeolite containin~ from 8~ to 10% by weight barium and from Ool~ ~O 1.5~ by weight platinum: and an inorganic binder selected rom the group consistin~ of silica, alumina, aluminosilicates, and clays. This sulfur-con-taminated catalyst is contacted at a temperature of about 80C with from 2 to 30 cc of an a~ueous potassium hydroxide solution per gram of catalyst. The aqueous solu-tion has a concentration of ~rom 1~ to 8~ by wei~ht of metal. After the catalyst is contacted with a solution, ~-~
it is washed with from 10 to 200 cc of water per gram of ;~
catalyst to remove excess metal, and then it is dried. --The catalyst can be washed with a neutral or ~~
acidic solution, then contacted with an aqueous solution ~257~
of an alkali metal salt or alkaline earth metal salt, then 05 washed with a neutral solution, and dried.
In a third embodiment, the present invention involves rejuvenating a large-pore zeolitic catalyst tha~
contains at least one Group VIII metal by washing the catalyst with a non-basic solution, contacting the washed 10 catalyst with an aqueous solution of a salt o~ a metal selected from the group consisting of an alkali metal and an alkaline earth metal, washing the contacted catalyst with a neutral solution; and drying the washed catalyst.
This regeneration procedure is useful, not only for sul-15 fur-contaminated catalysts, but also for catalysts deac-tivated by other means.
In the rejuvenation of a sulfur-contaminated catalyst, the present invention rejuvenates the catalyst without removing all the sulfur from the catalyst.
BACKGROUNV OF THE INVENTION
The present invention concerns a method for re~uvenating a zeolitic catalyst.
Catalytic refonming is a well known process that 10 is used to raise the octane rating of a naphtha for gasoline. The reactions that occur during refonmin~
include: dehydrocyclization of acyclic hydrocarbons, dehydrogenation of cyclohexanes~ dehydroisomerization of alkylcyclopentanes, isomerization of paraffins, dealky-15 lation of alkylbenzenes, and hydrocracking of paraffins.The hydrocracking reaction should be suppressed because that reaction lowers the yield of hydrogen and lowers the yield of liquid products.
Reforming catalysts must be selective for dehydrocyclization in order to produce high yields of liguid product and low yields of light gases. These cata-lysts should possess good activity, so that low tempera-tures can be used in the reformer. Also they should possess good stability, so that they can maintain a high 25 activity and a high selectivity for dehydrocyclization over a long period of time. Furthermore, they should be Ir-regenerable, so that they can be regenerated without loss of performance.
While most reforming catalysts contain platinum .
on an alumina support, other catalyst supports have heen proposed, such as lar~e-pore zeolites. These large-pore zeolites have pores large enough for hydrocarbons in the gasoline boiling range to pass through. Catalysts based on these zeolitic supports have been commercially unsuc-cessful.
~ ecently, a new catalyst was developed thatcomprises: a large-pore zeolite, a Group VIII metal, and an alkaline earth metal. This catalyst has a very high selectivity for dehydrocyclization, but it is hard to regenerate.
.~
,~
~257245 SUMMARY OF THE INVENTION
05 The present invention is based on the discovery that a catalyst can be rejuvenated by contacting the cata- `
lyst with an a~ueous media selected from the group con-sisting of water, an aqueous solution, and a saturated water vapor. This method of rejuvenation works for 10 large-pore zeolitic catalysts that contain at least one Group VIII metal~
In a first embodiment, at least lO cc of aqueous media must be used per cc of catalyst, and the aqueous media must be in the li~uid phase. Preferabl~, at least 15 500 cc of aqueous media is used per cc of catalyst. Prior to contacting the catalyst with an aqueous media, it should be exposed to oxidizing conditions, preferably at a temperature of from about 200C to about 450C. After the catalyst is contacted with an aqueous media, it should be 20 exposed to reducin~ conditions, preferably in the presence of hydrogen at a temperature of from about 200C to about 700C. The steps of oxidizing the catalyst, contactin~
the catalyst with an aqueous media, and reducing the cata-lyst can be repeated as necessary, until the catalyst is rejuvenated to the desired level.
A basic solution (i.e., pH greater than 7) can 1 be used instead of water or a saturated water vapor. In this embodiment, the catalyst is contacted with a basic solution at a temperature of from about 70C to about 80C. The basic solution can be an alkali metal hydroxide solution, such as potassium hydroxide solution having a pH
of at least lO.
In a second embodiment, a zeolitic catalyst can be rejuvenated, and the stability of that catalyst can be improved, by contacting the catalyst with an aqueous solu-tion of a metal salt or metal hydroxide, wherein the metal is either an alkali metal and an alkaline earth metal.
In a third embodiment, a zeolitic catalyst can .;
be reiuvenated by washing the catalyst with either a 4~ neutral or an acidic solution/ contacting the washed cata- ~
lyst with an aqueous solution of a metal salt or metal ~' ~2572~5 ol hydroxide (the metal is either an al~ali metal and an alkaline earth metal), washing the contacted catalyst with a neutral solution; and drying the twice washed catalyst.
This method is useful for both sulfur-contaminated cata-lysts and catalysts deactivated by other means~
Preferably, in the second and third embodiments, the concentration of the aqueous solution should be from 0.1% to 10~ by weight of metal. A more preferred concen-tration range is from 0.1% to 8~ by weight of metal.
Preferably, there is from 2 to 30 cc of aqueous solution per gram of catalyst in each washing step.
Preferably, in the second and third embodiments, the metal salt or hydroxide is either a metal halide, metal nitrate, metal carbonate, metal phosphate, or metal hydroxide. The preferred metal salt is a metal hydroxide, such as potassium hydroxide.
~O Preferably, in the second and third embodiments, the contacting occurs at a temperature of from 25C to 100C (more preferably, about 80C), then the catalyst that has been contacted with the aqueous solution is washed with from 10 to 200 cc of water per gram of cata-lyst to remove excess metal, and the washed catalyst is dried. Preferably, the catalyst is contacted with an oxidizing gas at conditions which favor oxidation before the first washing step.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In its broadest aspect, the present invention involves rejuvenating a catalyst by contacting the cata-lyst with a large quantity of an aqueous media in the liquid phase. This contacting step is an essential ele-ment of the present invention.
The aqueous media must he in the liquid phase.
If water in the li~uid phase is not present then the con-tacting step does not show the surprising re~eneration of the present invention.
Also, a large quantity of aqueous media is required. At least lO cc of aqueous media should be used ~:2572~5 per cc of catalyst. Rreferably, at least 500 cc of 05 aqueous media should be used per cc of catalyst.
This regeneration procedure is not only useful for sulfur-contaminated catalysts, but is also useful for catalysts deactivated by other means. ! ' A basic solution can be used to contact the 10 sulfur-contaminated catalyst at a temperature of from about 70C to about 80C. Preferably, the basic solution is an alkali metal hydroxide solution, such as a potassium hydroxide solution having a pH of at least 10. This embo-diment has the advantaqe o minimizing the formation of 15 acid sites on the catalyst.
A saturated water vapor in the liquid phase can be used to contact the sulfur-contaminated catalyst, pre-ferably at a temperature of from about 120C to about 180C. This embodiment has the advantage of allowing in situ treatment without having to remove or handle the catalyst.
The present invention rejuvenates the catalyst without removing all the sulfur from the catalyst. While it is not fully understood how the present invention achieves its surprising rejuvenation of sulfur-contami-nated catalysts, one theory is ~hat the washing might be converting the sulfur present in the catalyst to a state which is easier to be removed from the catalyst during the reduction and reforming process or a state which does not _`
interfere with the desired catalytic reaction~.
The catalyst can be exposed to oxidizing condi-tions prior to contactinq the catalyst with an agueous media. While the contacting step causes a sizable rejuve-nation of the catalyst, the combination of the oxidizing step and the contacting step causes a still more sizable rejuvenation. Preferably, the oxidation step occurs in ~-the presence of oxygen at a temperature of from about 200C to about 450C. The oxidation step alone does not rejuvenate the catalyst.
It is thought that the oxidation step changes the sulfur to a water-soluble form and/or weakens the ~2S7Z~S
01 _5_ association between platinum and sulfur. This could be effected with other oxidizing agents besides oxygen, such S as KMnO4, CrO3, etc. This could be applied to other metal-containing catalysts where sulfur is known to harm activity.
The catalyst can be exposed to reducin~ condi-tions after contacting the catalyst with an aqueous media.
10 Preferably, the reduction step occurs in the presence o hydrogen at a temperature of from 200C to 700C. Note that no rejuvenatlon occurs from the reduction step alone, or from reduction following oxidation without including the water step.
The ef~ectiveness oE this reducing step may depend on whether the solvent molecules shielding the platinum are removed faster than the sulfur is reduced.
In this context, we have discovered that if the water treatment employs wet hydrogen, a more stable rejuvenated catalyst is obtained. Other reducing agents, such as water-soluble hydrazine-hydrate, NaBH4, and KBH4, could also be used for this step.
The combination of the oxidizing step, the soak-ing step, and the reducing step causes a still more sizable reiuvenation than the combination of the soaking step with either only the oxidizing step or only the reducing step. These three steps can be repeated, as needed, until the catalyst is rejuvenated to the desired level.
A sulfur-contaminated catalyst can be exposed to oxidizing conditions in the presence of oxygen at a tem-perature of from about 200C to about 450C, the oxidized catalyst is contacted with at least 500 cc of a saturated water vapor in the liquid phase per cc of catalyst at a temperature of from about 120C to about 180C, then the catalyst is exposed to reducing conditions in the presence of hydrogen at a temperature of from 200C to about 700C.
These steps are repeated until the catalyst is rejuvenated to the desired level.
'10 ~572~5 In a second embodiment, a large-pore zeolitic catalyst that contains at least one Group VIII metal is rejuvenated by contactin~ the catalyst with an aqueous solution of a salt of a metal selected from the 0roup consisting of an alkali metal and an alkaline earth metal.
An essential step of this embodiment is that the 10 catalyst must be contacted with an aqueous solution of a salt or hydroxide of a metal selected from the group con-sisting of an alkali metal and an alkaline earth metal.
The metal salt or hydroxide may be either a metal halide, -metal nitrate, metal carbonate, metal phosphate, or metal 15 hydroxide. Preferably, the metal salt or hydroxide is potassium hydroxide. Preferably, the catalyst is con-tacted with from 2 to 30 cc of aqueous solution per gram of catalyst at a temperature of from 25C to 100C, more preferably at a temperature of about 80C. The aqueous solution should have a concentration of from 0.1~ to 10%
by weight of metal, preferably from 1% to 8% by weight of metal.
After the catalyst has been contacted with the aqueous solution, the catalyst is washed with ~rom 10 to 200 cc of water per gram of catalyst to remove excess metal, then the washed catalyst is dried. , r The sulfur-contaminated catalyst can comprise a type L zeolite containin~ from 8~ to 10% by weight barium and from Ool~ ~O 1.5~ by weight platinum: and an inorganic binder selected rom the group consistin~ of silica, alumina, aluminosilicates, and clays. This sulfur-con-taminated catalyst is contacted at a temperature of about 80C with from 2 to 30 cc of an a~ueous potassium hydroxide solution per gram of catalyst. The aqueous solu-tion has a concentration of ~rom 1~ to 8~ by wei~ht of metal. After the catalyst is contacted with a solution, ~-~
it is washed with from 10 to 200 cc of water per gram of ;~
catalyst to remove excess metal, and then it is dried. --The catalyst can be washed with a neutral or ~~
acidic solution, then contacted with an aqueous solution ~257~
of an alkali metal salt or alkaline earth metal salt, then 05 washed with a neutral solution, and dried.
In a third embodiment, the present invention involves rejuvenating a large-pore zeolitic catalyst tha~
contains at least one Group VIII metal by washing the catalyst with a non-basic solution, contacting the washed 10 catalyst with an aqueous solution of a salt o~ a metal selected from the group consisting of an alkali metal and an alkaline earth metal, washing the contacted catalyst with a neutral solution; and drying the washed catalyst.
This regeneration procedure is useful, not only for sul-15 fur-contaminated catalysts, but also for catalysts deac-tivated by other means.
In the rejuvenation of a sulfur-contaminated catalyst, the present invention rejuvenates the catalyst without removing all the sulfur from the catalyst.
2~Before the catalyst has been contacted with the aqueous solution, the catalyst is washed with from lO to 200 cc of either a neutral solution or an acidic solution per gram of catalyst.
An essential step of this embodiment is that the catalyst must be contacted with an a~ueous solution of a salt or hydroxide of a metal selected from the group con- 1~.
sisting of an alkali metal and an alkaline earth metal.
The metal salt or hydroxide may be either a metal halide, metal nitrate, metal carbonate, metal phosphate, or metal hydroxide. Preferably, the catalyst is contacted with from 2 to 30 cc of a~ueous solution per gram of catalyst at a temperature of from 2SC to lOOC, more preferably at a temperature of about 80C. The aqueous solution should ha~e a concentration o from 0.l% to 10% by weight of
An essential step of this embodiment is that the catalyst must be contacted with an a~ueous solution of a salt or hydroxide of a metal selected from the group con- 1~.
sisting of an alkali metal and an alkaline earth metal.
The metal salt or hydroxide may be either a metal halide, metal nitrate, metal carbonate, metal phosphate, or metal hydroxide. Preferably, the catalyst is contacted with from 2 to 30 cc of a~ueous solution per gram of catalyst at a temperature of from 2SC to lOOC, more preferably at a temperature of about 80C. The aqueous solution should ha~e a concentration o from 0.l% to 10% by weight of
3~ metal, preferably from 0.1% to 8~ by weight of metal.
After the catalyst has been contacted with the aqueous solution, the catalyst is washed with from lO to t' 200 cc of water per gram of catalyst to remove excess metal, then the washed catalyst is dried.
4n ^
~;~57Z~5 Preferably, the catalyst is contacted with an 05 oxidizing gas at conditions which favor oxidation before the ~irst washing step.
In one preferred method in this embodiment, the deactivated catalyst is a sulfur-contaminated catalyst that comprises a type L zeolite containinq from 8~ to 10~
10 by weight barium and from 0.1% to 1.5~ by weight platinum;
and an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays. This sulfur-contaminated catalyst is contacted with an oxidizing gas at conditions which favor oxidation, then the catalyst is washed with a neutral solution, then the catalyst is contacted at a temperature of about 80C with from 2 to 30 cc o~ an aqueous potassium hydroxide solution per gram of catalyst. The agueous solution has a concen-tration of from 0.1% to 8% by wei~ht of alkali or alkaline earth metal. After the catalyst is contacted with a solu-tion, it is washed with from 10 to 200 cc of water per gram of catalyst to remove excess metal, then it is dried.
One reforming catalyst that can be regenerated by the present invention is a large-pore zeolite charged 25 with one or more dehydrogenating constituents. The term "large-pore zeolite" is defined as a zeolite having an "
effective pore diameter of 6 to 15 Angstroms.
Type L zeolite, zeolite X, zeolite Y and faujasite are thought to be the best large-pore zeolites 30 for this operation and have apparent pore sizes on the order o~ from 7 to 9 Angstroms. The preferred catalyst is a type L zeolite charged with one or more dehydrogenatin~
constituents.
An alkaline earth metal can be present in the 35 catalyst. That alkaline earth metal can be either barium, strontium or calcium. The alkaline earth metal can be ~r,~
incorporated into the zeolite by synthesis, impregnation or ion exchange. Barium is preferred to the other alkaline earths because the resulting catalyst has high 40 activity, hiqh selecti~ity and hiqh stability. The barium should prefer~bly constitute from about 0.1~ to about 35%
r ~257245 01 _9_ of the weight of the zeolite, more preferably from about 1% to about 20% by weight.
The reforming catalysts according to the inven-tion are charged with one or more Group VIII metals, e.~., nickel, ruthenium, rhodium, palladium, iridium or platinum.
The preferred Group VIII metal is platinum, which is more selective with regard to dehydrocyclization and is also more stable under the reform;ng reaction con-ditions than other Group VIII metals. The preferred per-centage of platinum in the catalyst is between 0.1~ and 5%, more preerably from 0.1% to 1.5%.
An inorganic oxide can be used as a carrier to bind the large pore size zeolite. The carrier can be a natural or a synthetically produced inorganic oxide or combination of inorganic oxides. Preferred loadings of inorganic oxide are from 5% to 50g by weight of the cata-lyst. Typical inorganic oxide supports which can be used ~-- include silica, alumina, and aluminosilicates.
EXAMPLES
The first embodiment of the present invention will be further illustrated by the following examples which set forth a particularly advantageous method and composition embodiments. While the examples are provided to illustrate the present invention, they are not intended to limit it. ~
Example I
A catalyst was prepared by ~l) ion exchanging a potassium-type L æeolite with a sufficient volume of ~o17 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity of the zeolite; 12) drying the resulting barium-exchanged type L
zeolite catalyst; (3) calcining the catalyst at 590C; 3`
After the catalyst has been contacted with the aqueous solution, the catalyst is washed with from lO to t' 200 cc of water per gram of catalyst to remove excess metal, then the washed catalyst is dried.
4n ^
~;~57Z~5 Preferably, the catalyst is contacted with an 05 oxidizing gas at conditions which favor oxidation before the ~irst washing step.
In one preferred method in this embodiment, the deactivated catalyst is a sulfur-contaminated catalyst that comprises a type L zeolite containinq from 8~ to 10~
10 by weight barium and from 0.1% to 1.5~ by weight platinum;
and an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays. This sulfur-contaminated catalyst is contacted with an oxidizing gas at conditions which favor oxidation, then the catalyst is washed with a neutral solution, then the catalyst is contacted at a temperature of about 80C with from 2 to 30 cc o~ an aqueous potassium hydroxide solution per gram of catalyst. The agueous solution has a concen-tration of from 0.1% to 8% by wei~ht of alkali or alkaline earth metal. After the catalyst is contacted with a solu-tion, it is washed with from 10 to 200 cc of water per gram of catalyst to remove excess metal, then it is dried.
One reforming catalyst that can be regenerated by the present invention is a large-pore zeolite charged 25 with one or more dehydrogenating constituents. The term "large-pore zeolite" is defined as a zeolite having an "
effective pore diameter of 6 to 15 Angstroms.
Type L zeolite, zeolite X, zeolite Y and faujasite are thought to be the best large-pore zeolites 30 for this operation and have apparent pore sizes on the order o~ from 7 to 9 Angstroms. The preferred catalyst is a type L zeolite charged with one or more dehydrogenatin~
constituents.
An alkaline earth metal can be present in the 35 catalyst. That alkaline earth metal can be either barium, strontium or calcium. The alkaline earth metal can be ~r,~
incorporated into the zeolite by synthesis, impregnation or ion exchange. Barium is preferred to the other alkaline earths because the resulting catalyst has high 40 activity, hiqh selecti~ity and hiqh stability. The barium should prefer~bly constitute from about 0.1~ to about 35%
r ~257245 01 _9_ of the weight of the zeolite, more preferably from about 1% to about 20% by weight.
The reforming catalysts according to the inven-tion are charged with one or more Group VIII metals, e.~., nickel, ruthenium, rhodium, palladium, iridium or platinum.
The preferred Group VIII metal is platinum, which is more selective with regard to dehydrocyclization and is also more stable under the reform;ng reaction con-ditions than other Group VIII metals. The preferred per-centage of platinum in the catalyst is between 0.1~ and 5%, more preerably from 0.1% to 1.5%.
An inorganic oxide can be used as a carrier to bind the large pore size zeolite. The carrier can be a natural or a synthetically produced inorganic oxide or combination of inorganic oxides. Preferred loadings of inorganic oxide are from 5% to 50g by weight of the cata-lyst. Typical inorganic oxide supports which can be used ~-- include silica, alumina, and aluminosilicates.
EXAMPLES
The first embodiment of the present invention will be further illustrated by the following examples which set forth a particularly advantageous method and composition embodiments. While the examples are provided to illustrate the present invention, they are not intended to limit it. ~
Example I
A catalyst was prepared by ~l) ion exchanging a potassium-type L æeolite with a sufficient volume of ~o17 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity of the zeolite; 12) drying the resulting barium-exchanged type L
zeolite catalyst; (3) calcining the catalyst at 590C; 3`
(4) impregnating the catalyst with 0.8% platinum using tetrammineplatinum tII) nitrate; (5) drying the catalyst;
(6~ calcining the catalyst at 260C; and 17~ reducing the catalyst in hydrogen at 480C to 500C.
~Z572~5 --l o--Example II
05 The catalyst of Example I was used in a pilot plant to reform n-hexane that had been hydrofined to remove sulfur, oxygen and nitrogen. The refonming occurred at 860F, lO0 psig, 17 LHSV, and 5 H2/HC. The results after ten and twenty hours are listed in Table I.
Example III
~0 The catalyst of Example I was used in a pilot plant to reform naphtha that had been hydrofined to remove sulfur, oxygen and nitrogen and then to which sulfur com-pounds were deliberately added in or~er to generate a 15 sulfur-contaminated catalyst. The reforming occurred at 860F, lO0 psig. 1.5 LHSV, and 6 H2/HC for 3 weeks to produce a sulfided catalyst, then the sulfided catalyst was tested by the procedures of Example II. The results of that test after ten and twenty hours are listed in Table I.
Exam~le IV
The sulfided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then the catalyst was tested by the procedures of Example II. The results of that test after ten and twenty hours are listed in Table I.
Example V
The sulfided catalyst of Example III was washed with 80C water at 2cc/min for one hour, then the catalyst was tested by the procedures of Example II. T~e results of that test after ten and twenty hours are listed in Table I.
Example VI
The sulfided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then washed with lO0~ steam at 212F for 3 hours, then the catalyst was tested by the procedures of Example II. The results o that test after ten and twenty hours are listed in Table I.
t -~2~7:~S
Example VII
05 The sulfided catalyst of Example III was oxidized at one atmosphere with 1~ oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F: then washed with 100~ steam at 212F for 3 hours;
then reduced in H2 for 1-1/2 hours at 900F, then oxidized 1O at one atmosphere with 1% oxygen in nitrogen for one half hour at 400~F, one hour at 500F, and 5 hours at 750F;
then washed with 100% steam at 212F for 3 hours; then the catalyst was tested by the procedures o~ Example II. The results of that test after ten and twenty hours are listed 15 in Table I.
Example VIII
The sulided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then washed with 100% steam at 212F for 3 hours;
then reduced at 900F in H2 for 1-1/2 hours, then oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F: ;
then washed with 100% steam at 212F for 3 hours; then reduced at 900F in H2 for 1-1/2 hours, then oxidized at one atmosphere with 1% oxygen in nitrogen for one half l-hour at 400F, one hour at 500F and 5 hours at 750F;
then washed with 100~ steam at 212F for 3 hours; then the catalyst was tested by the procedures of Example II. The results of that test ater ten and twenty hours are listed in Table I.
3 5 ~ r r . ~
- ~257~ S
Table I
Relative Rate Constants for C6 saturates Benzene % Selectivity conversion formation at to Benzene at at time on time on time on Stream Stream Stream lOh 2Oh lOh 2Oh lOh 2Oh Example II 1 1 1 1 86 85 Example III 0.08 0.09 0.01 0.01 11 12 Example IV 0.21 0.18 0.10 0.09 40 45 Example V 0.19 0.19 0.10 0.10 45 45 Example VI 0.71 0.74 0.53 0.56 75 7 Example VII 0.81 0.80 0.80 0.76 84 81 Example VIII 0.81 0.80 0.80 0.76 84 81 ; Examples V, VI, VII, and VIII are examples of the . 10 present invention. They show that washing, either alone or in ~-~ conjunction with oxidation, rejuvenated deactivated catalysts.
Example IX
; The second embodiment of the present invention will be further illustrated by the following examples which set forth particularly advantageous method and composition embodi-ments. While the examples are provided to illustrate the present invention, they are not intended to limit it.
Fresh reforming catalyst was prepared by (1) ion exchanging a potassium-type L with a sufficient volume of 0.17 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity o~ the zeolite; (2) dry-ing the resulting barium-exchanged type L zeolite catalyst;
(3) calcining the catalyst at 590C, (4) impregnating the ~2S~4S
catalyst by pore fill impregnation with 0.8% platinum using tetrammineplatinum (II) nitra-te; (5) drying the catalyst; (6) calcining the catalyst at 260C; and (7) reducing the catalyst in hydrogen at 480C to 500C.
A second portion of the fresh reforming catalyst was deactivated by contacting the catalyst with a sulfur-containing light straight run until about 200 ppm sulfur was deposited on the catalyst. The deactivated catalyst was rejuvenated by contacting the catalyst for two hours a-t a temperature of about 80##?C with an aqueous solution of potassium hydroxide having a concentration of 5% by weight of metal, wherein there was 30 cc of aqueous solution per gram of catalyst; washing the catalyst that had been contacted with the aqueous solution ten times with 20 cc of water per gram of catalyst (200 cc total wash) to remove excess metal; and drying the washed catalyst.
A feed of n-hexane, which had been hydrofined to remove sulfur, oxygen and nitrogen, was contacted at 920F, lO0 psig, 10 LHSV, and 5 H2/HC with the rejuvenated reforming catalyst.
Examples X through XXIII
The third embodiment of the present invention will be further illustrated by the following examples which set -forth particularly advantageous method and composition embodiments.
While the examples are provided to illustrate the present invention, they are not intended to limit it.
A type L zeolite reforming catalyst was treated with a sulfur-containing hydrocarbon feed until the catalyst was substantially deactivated. The catalyst had been prepared by (l) extruding the catalyst with 20 wt. ~ of an alumina inor-ganic oxide binder in the shape of l/16th inch extrudate; (2) ~25724LS
- 13a - 61936-1687 ion exchanging a potassium-type L 7eolite with a suficient volume of 0.3 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity of the zeolite; (3) drying the resulting barium-exchanged type L
zeolite; (4) calcining the catalyst at 530C; (5) impregnating the catalyst with 0.8%
~,~
~:~S7245 -lA-platinum based on the weight of L zeolite using 05 tetrammineplatinum (II) nitrate; (6) drying the catalyst;
(7) calcining the catalyst at 260C in air or 50% steam;
(~) extruding the catalyst with 20 wt. ~ of an alumina inorganic oxide binder in the shape of l/l6th inch extru-date; and (9) reducing the catalyst in hydrogen at 480C
- 10 to 500C. The catalyst had been deactivated by the proce-dure of running it onstream at mild reforming conditions (l00 psig, 870F, 2 H2/HC, 1.5 LHSV) with a sul~ur-con-taining naphtha feedstoc~ (l.5 ppm dimethyl disulfide).
That catalyst was then subjected to a variety of regener-ation procedures, and then was tested by the following test.
REGENERATION TEST
0.356 Grams of catalyst screened to 24 to 80 mesh was placed in a tubular reactor. A low surface area alpha alumina was placed above and below the catalyst. The catalyst was treated at 400F in hydrogen flowing at 500 cc/min. for one-half hour, then at 880F in hydrogen for 10 minutes, then at 920F in hydrogen for one hour.
After one hour at 920F the flow of hydrogen was cut back to 60 cc/min. and the pressure was built up from atmos-pheric pressure to l00 psi~. At this point, n-hexane was introduced at 3 cc/hr. Initial and final data was taken at approximately two hours and 18 ho~rs after introducinq the n-hexane feed. The conversion (Conv.), selectivity -for dehydrocyclization ~Sel.), and yield of aromatics in product as mole % of the feed (Mole ~) were calculated at those times.
Example X
The catalyst in this example was not treated to any regeneration procedures.
Example XI
The catalyst in this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five ~257245 hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500~F
for two hours 1~
Example XII
The catalyst in this example was placed into a quartz reactor tube in a furnace, then 1~ oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram 15 catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F ~or five hours~ The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst ! , was, for three times: (1) treated for 30 minutes at 165F
2~ with a ten-fold excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) cooled, and (3) filtered.
Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Example XIII
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro- t;~
gen was passed over the catalyst at a rate of 2 cc/gram ca~alyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was heated to 176F for two hours, and occasionally stirred, in the presence of a twenty-fold excess of an aqueous solution of 4 wt. % ~OH, then cooled and filtered.
Then the catalyst was for nine times: ~1) mixed with a ten-fold excess of water at room temperature for one ,-minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for ^.
20 hours and treated in flowing air at 500F Eor two hours.
.
~:Z S724~
Table II shows the effect of the reqeneration procedures of Examples X through XIII. From this table, It is apparent that regeneration with a preliminary oxida-tion, followed by contact with water or an aqueous solution, followed by drying and calcinin~, qives a sub-stantial regeneration of the deactivated catalyst. Of these four examples, Example XIII (KOH wash) ~ave the best results.
TABLE II
The Effect of Re~eneration with Water Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
__ X4.96 43.272.15 3.93 62.292.45 XI42.07 85.7936.09 28.78 87.2525.11 XII14.58 68. 9.85 10.58 73.7.67 ~ XIII40.72 87.4935.63 36.29 90.6432.90 Example XIV
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gramcatalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxy~en was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, and (3) filtered. Then, the catalyst was, for three times: (1) heated to 135F or one hour in the presence of a ten-fold excess of an aqueous solution of 0.lN KOH, ~2) cooled, and (3) filtered. The catalyst was then washed with a ten-fold excess of deionized water at 140F
for one hour, then was cooled and filtered. Then the catalyst was dried in air at 250F or two hours and -treated in flowin~ air at 500F for two hours.
.~
~2S72~5 Table III shows the improvement obtainable when the catalyst is treated with a neutral solution prior to a 05 KOH wash. From the table, it can be clearly seen that washing the catalyst with a neutral wash prior to the KOH
wash gives better results than when there is no neutral wash.
TABLE III
The Effect of Neutral Wash Prior to KOH Wash Initial Final Example _onv. Sel. Mole ~ Conv. Sel. Mole %
XIII 40.72 87.49 35.63 36.29 90.64 32.90 XIV 56.73 93.13 52.83 54.15 95.10 51.49 Example XV
The catalyst of this example was heated to 176F
for two hours, and occasionally stirred, in the presence - of a twenty-fold excess of an aqueous solution of 4 wt. ~
KOH, then cooled and filtered. Then the catalyst was, for nine times: (1) mixed with a ten-fold excess of water at room temperature for one minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours and treated in fLowing air at 500F for two hours. i~
Example XVI
The catalyst of this example was, for three times: (1) treated for 30 minute at 165F in a ten-fold excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) then cooled and filtered. Then the cata-lyst was, ~or three times: (1) mixed with a ten-fold excess of a solution of 0.lN KOH, (2) treated with the KOH
solution for one hour at 135F, (3) cooled, and (4) fil-tered. Then the catalyst was treated with a ten-fold excess of deionized water at 135F, cooled, and filtered.
Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
'. , '`' , ,, '. '' J
~2572~5 Example XVII
The catalyst o this exa~ple was placed into a S quartz reactor tube in a ~urnace, then 1% oxygen in nitro-~en was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow o~ oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F. (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F in a ten-fold excess of a solution of O.lN sodium carbonate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F in a ten-fold excess of :-deionized water, (2), and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in ~~
flowing air at 500F for two hours.
Example XVIII
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1~ oxy~en in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at ~00F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated for 30 minutes at 165F
with a ten-fold excess of an Aqueous solution of hydrogen chloride havin~ a pH of 3, (2) cooledr and (3) filtered.
Then the catalyst was, for three times: (1) treated for one hour at 135F with a seven-fold excess of a solution of O.lN sodium carbonate, (2) cooled, and (3) filtered.
Then the catalyst was, for three times: (1) treated at 135F for one hour with a seven-fold excess o~ deionized water, (2) cooled~ and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F or two hours.
. . , . ;. ........... . - .
. . .
~257~4s Table IV shows the further improvement obtain-able with preliminary treatment with an acidic solution.
Two pairs of data are shown, the first in each case treated with a neutral solution or no solution at all prior to treatment with the salt solution, the second in each case treated with an acidic solution first. In the di~ferences between the first pair of data and the second, note also the advantages of using pre-oxidation prior to the aqueous treatments, particularly if the acidic treat-ment step has been omitted.
TABLE III
-- :
The Effect of Acidic Wash Prior to Salt Wash Without Pre-Oxidation Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XV 27.53 82.13 22.61 8.42 65.~5 5.51 XVI 56.84 93.48 53.13 58.52 96.08 56.23 With Pre-Oxidation Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XVII 47.96 89. 29 42.82 41.77 91.84 38.36 ~`
XVIII 61.92 88.01 54.49 55.66 91.12 50.72 Example XI~
The catalyst of this example was heated to 176F
for two hours, and occasionally stirred, in the presence F
35 of a twenty-fold excess of an aqueous solution of 4 wt. %
KOH, then cooled and filtered. Then the catalyst was r for nine times: (1) mixed with a ten-fold excess of water at room temperature for one minute, (2~ allowed to settle for three minutes, and (3) filtered. At this point, the pE~ of ~2S7Z~5 the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours.
05 Example XX
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1~ oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one 10 hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was heated to 176F for two hours, and occasionally stirred, in the presence of a twenty-fold excess o~ an lS aqueous solution of 4 wt. % KOH, then cooled and filtered.
Then the catalyst was, for nine times: (1) mixed with a ten-fold excess of water at room temperature for one ! ' minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours.
Example XXI
The catalyst of this example was, for three times: (1) treated for 30 minutes at 165F with a ten-fold excess of an aqueous solution of hydrogen chloridehavin~ a pH of 3, (2) cooled, and (3) filtered. Then, the catalyst was, for three times (1) treated for one hour at 135F with an aqueous solution of 0.lN sodium carbonate, ~2) cooled, and ~3) filtered. Then the catalyst wasr for three times: (1) treated for one hour at 140F with a ten-fold excess of deionized water, (2) cooled and (3) fil-tered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Table V shows the importance of using a pre- -oxidation step. It sets forth pairs of data obtained with `~-and without this step. ~~
~57245 01 ~21-TABLE V
The Effect o Pre-Oxidation 1)5 Initial Final Example Conv. Sel. Mole 96 Conv. Sel~ Mole %
XIX 24.73 83.68 20069 18.86 82.67 15.59 XX 39.86 8~.53 35.29 31.31 89.29 27~95 - XXI 55.26 88.85 49. 3~ 49.88 92.90 46. 34 XVII 61.92 88.01 54.49 55.66 91.12 50.72 Example XXIIThe catalyst of this example was placed into a quartz reactor tube in a furnace, then 196 oxygen in nitrogen was ~assed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F
for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the catalyst was cooled to room temperature. Then the cata-lyst was, for three times: (1) treated for 30 minutes at 165F with a ten-fol(l excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F with a seven-fold excess of a solution of O.lN ma~nesium nitrate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated at 135F for one hour with a seven-fold excess of deionized water, ~2) cooled, and (3) filtered. Then 30 the catalyst was dried in air at 250F for two hours and treated in flowin~ air at 500F for two hours.
~ ` ;
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro- ~@
35 gen was passed over the catalyst at a rate of 2 cc/grams catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst r~
40 was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, ~}`-tb~ r~
.
' ~
~2S7245:
-and filtered. Then the catalyst was, for three times:
tl) treated for one hour at 135F with a ten-fold excess of a solution of O.lN magnesium nitrate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated ~or one hour at 140F with a ten-fold excess of deionized water, (2~ cooled, and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Finally, Table VI shows two unsuccessful treat-ments, one with a preliminary acidic treatment, and the other without.
TABLE VI
Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XXII 6.10 27.41 1~67 3.05 30.00 1~19 XXIII 5.78 21.82 1.26 Too low to calculate ~-While the present invention has been described with reference to specific embodiments, this application is intended to cover those changes which may be made by those skilled in the art without departing from the spirit and scope o~ the appended claims.
~0 .
(6~ calcining the catalyst at 260C; and 17~ reducing the catalyst in hydrogen at 480C to 500C.
~Z572~5 --l o--Example II
05 The catalyst of Example I was used in a pilot plant to reform n-hexane that had been hydrofined to remove sulfur, oxygen and nitrogen. The refonming occurred at 860F, lO0 psig, 17 LHSV, and 5 H2/HC. The results after ten and twenty hours are listed in Table I.
Example III
~0 The catalyst of Example I was used in a pilot plant to reform naphtha that had been hydrofined to remove sulfur, oxygen and nitrogen and then to which sulfur com-pounds were deliberately added in or~er to generate a 15 sulfur-contaminated catalyst. The reforming occurred at 860F, lO0 psig. 1.5 LHSV, and 6 H2/HC for 3 weeks to produce a sulfided catalyst, then the sulfided catalyst was tested by the procedures of Example II. The results of that test after ten and twenty hours are listed in Table I.
Exam~le IV
The sulfided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then the catalyst was tested by the procedures of Example II. The results of that test after ten and twenty hours are listed in Table I.
Example V
The sulfided catalyst of Example III was washed with 80C water at 2cc/min for one hour, then the catalyst was tested by the procedures of Example II. T~e results of that test after ten and twenty hours are listed in Table I.
Example VI
The sulfided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then washed with lO0~ steam at 212F for 3 hours, then the catalyst was tested by the procedures of Example II. The results o that test after ten and twenty hours are listed in Table I.
t -~2~7:~S
Example VII
05 The sulfided catalyst of Example III was oxidized at one atmosphere with 1~ oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F: then washed with 100~ steam at 212F for 3 hours;
then reduced in H2 for 1-1/2 hours at 900F, then oxidized 1O at one atmosphere with 1% oxygen in nitrogen for one half hour at 400~F, one hour at 500F, and 5 hours at 750F;
then washed with 100% steam at 212F for 3 hours; then the catalyst was tested by the procedures o~ Example II. The results of that test after ten and twenty hours are listed 15 in Table I.
Example VIII
The sulided catalyst of Example III was oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F; then washed with 100% steam at 212F for 3 hours;
then reduced at 900F in H2 for 1-1/2 hours, then oxidized at one atmosphere with 1% oxygen in nitrogen for one half hour at 400F, one hour at 500F, and 5 hours at 750F: ;
then washed with 100% steam at 212F for 3 hours; then reduced at 900F in H2 for 1-1/2 hours, then oxidized at one atmosphere with 1% oxygen in nitrogen for one half l-hour at 400F, one hour at 500F and 5 hours at 750F;
then washed with 100~ steam at 212F for 3 hours; then the catalyst was tested by the procedures of Example II. The results of that test ater ten and twenty hours are listed in Table I.
3 5 ~ r r . ~
- ~257~ S
Table I
Relative Rate Constants for C6 saturates Benzene % Selectivity conversion formation at to Benzene at at time on time on time on Stream Stream Stream lOh 2Oh lOh 2Oh lOh 2Oh Example II 1 1 1 1 86 85 Example III 0.08 0.09 0.01 0.01 11 12 Example IV 0.21 0.18 0.10 0.09 40 45 Example V 0.19 0.19 0.10 0.10 45 45 Example VI 0.71 0.74 0.53 0.56 75 7 Example VII 0.81 0.80 0.80 0.76 84 81 Example VIII 0.81 0.80 0.80 0.76 84 81 ; Examples V, VI, VII, and VIII are examples of the . 10 present invention. They show that washing, either alone or in ~-~ conjunction with oxidation, rejuvenated deactivated catalysts.
Example IX
; The second embodiment of the present invention will be further illustrated by the following examples which set forth particularly advantageous method and composition embodi-ments. While the examples are provided to illustrate the present invention, they are not intended to limit it.
Fresh reforming catalyst was prepared by (1) ion exchanging a potassium-type L with a sufficient volume of 0.17 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity o~ the zeolite; (2) dry-ing the resulting barium-exchanged type L zeolite catalyst;
(3) calcining the catalyst at 590C, (4) impregnating the ~2S~4S
catalyst by pore fill impregnation with 0.8% platinum using tetrammineplatinum (II) nitra-te; (5) drying the catalyst; (6) calcining the catalyst at 260C; and (7) reducing the catalyst in hydrogen at 480C to 500C.
A second portion of the fresh reforming catalyst was deactivated by contacting the catalyst with a sulfur-containing light straight run until about 200 ppm sulfur was deposited on the catalyst. The deactivated catalyst was rejuvenated by contacting the catalyst for two hours a-t a temperature of about 80##?C with an aqueous solution of potassium hydroxide having a concentration of 5% by weight of metal, wherein there was 30 cc of aqueous solution per gram of catalyst; washing the catalyst that had been contacted with the aqueous solution ten times with 20 cc of water per gram of catalyst (200 cc total wash) to remove excess metal; and drying the washed catalyst.
A feed of n-hexane, which had been hydrofined to remove sulfur, oxygen and nitrogen, was contacted at 920F, lO0 psig, 10 LHSV, and 5 H2/HC with the rejuvenated reforming catalyst.
Examples X through XXIII
The third embodiment of the present invention will be further illustrated by the following examples which set -forth particularly advantageous method and composition embodiments.
While the examples are provided to illustrate the present invention, they are not intended to limit it.
A type L zeolite reforming catalyst was treated with a sulfur-containing hydrocarbon feed until the catalyst was substantially deactivated. The catalyst had been prepared by (l) extruding the catalyst with 20 wt. ~ of an alumina inor-ganic oxide binder in the shape of l/16th inch extrudate; (2) ~25724LS
- 13a - 61936-1687 ion exchanging a potassium-type L 7eolite with a suficient volume of 0.3 molar barium nitrate solution to contain an excess of barium compared to the ion exchange capacity of the zeolite; (3) drying the resulting barium-exchanged type L
zeolite; (4) calcining the catalyst at 530C; (5) impregnating the catalyst with 0.8%
~,~
~:~S7245 -lA-platinum based on the weight of L zeolite using 05 tetrammineplatinum (II) nitrate; (6) drying the catalyst;
(7) calcining the catalyst at 260C in air or 50% steam;
(~) extruding the catalyst with 20 wt. ~ of an alumina inorganic oxide binder in the shape of l/l6th inch extru-date; and (9) reducing the catalyst in hydrogen at 480C
- 10 to 500C. The catalyst had been deactivated by the proce-dure of running it onstream at mild reforming conditions (l00 psig, 870F, 2 H2/HC, 1.5 LHSV) with a sul~ur-con-taining naphtha feedstoc~ (l.5 ppm dimethyl disulfide).
That catalyst was then subjected to a variety of regener-ation procedures, and then was tested by the following test.
REGENERATION TEST
0.356 Grams of catalyst screened to 24 to 80 mesh was placed in a tubular reactor. A low surface area alpha alumina was placed above and below the catalyst. The catalyst was treated at 400F in hydrogen flowing at 500 cc/min. for one-half hour, then at 880F in hydrogen for 10 minutes, then at 920F in hydrogen for one hour.
After one hour at 920F the flow of hydrogen was cut back to 60 cc/min. and the pressure was built up from atmos-pheric pressure to l00 psi~. At this point, n-hexane was introduced at 3 cc/hr. Initial and final data was taken at approximately two hours and 18 ho~rs after introducinq the n-hexane feed. The conversion (Conv.), selectivity -for dehydrocyclization ~Sel.), and yield of aromatics in product as mole % of the feed (Mole ~) were calculated at those times.
Example X
The catalyst in this example was not treated to any regeneration procedures.
Example XI
The catalyst in this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five ~257245 hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500~F
for two hours 1~
Example XII
The catalyst in this example was placed into a quartz reactor tube in a furnace, then 1~ oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram 15 catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F ~or five hours~ The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst ! , was, for three times: (1) treated for 30 minutes at 165F
2~ with a ten-fold excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) cooled, and (3) filtered.
Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Example XIII
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro- t;~
gen was passed over the catalyst at a rate of 2 cc/gram ca~alyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was heated to 176F for two hours, and occasionally stirred, in the presence of a twenty-fold excess of an aqueous solution of 4 wt. % ~OH, then cooled and filtered.
Then the catalyst was for nine times: ~1) mixed with a ten-fold excess of water at room temperature for one ,-minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for ^.
20 hours and treated in flowing air at 500F Eor two hours.
.
~:Z S724~
Table II shows the effect of the reqeneration procedures of Examples X through XIII. From this table, It is apparent that regeneration with a preliminary oxida-tion, followed by contact with water or an aqueous solution, followed by drying and calcinin~, qives a sub-stantial regeneration of the deactivated catalyst. Of these four examples, Example XIII (KOH wash) ~ave the best results.
TABLE II
The Effect of Re~eneration with Water Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
__ X4.96 43.272.15 3.93 62.292.45 XI42.07 85.7936.09 28.78 87.2525.11 XII14.58 68. 9.85 10.58 73.7.67 ~ XIII40.72 87.4935.63 36.29 90.6432.90 Example XIV
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gramcatalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxy~en was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, and (3) filtered. Then, the catalyst was, for three times: (1) heated to 135F or one hour in the presence of a ten-fold excess of an aqueous solution of 0.lN KOH, ~2) cooled, and (3) filtered. The catalyst was then washed with a ten-fold excess of deionized water at 140F
for one hour, then was cooled and filtered. Then the catalyst was dried in air at 250F or two hours and -treated in flowin~ air at 500F for two hours.
.~
~2S72~5 Table III shows the improvement obtainable when the catalyst is treated with a neutral solution prior to a 05 KOH wash. From the table, it can be clearly seen that washing the catalyst with a neutral wash prior to the KOH
wash gives better results than when there is no neutral wash.
TABLE III
The Effect of Neutral Wash Prior to KOH Wash Initial Final Example _onv. Sel. Mole ~ Conv. Sel. Mole %
XIII 40.72 87.49 35.63 36.29 90.64 32.90 XIV 56.73 93.13 52.83 54.15 95.10 51.49 Example XV
The catalyst of this example was heated to 176F
for two hours, and occasionally stirred, in the presence - of a twenty-fold excess of an aqueous solution of 4 wt. ~
KOH, then cooled and filtered. Then the catalyst was, for nine times: (1) mixed with a ten-fold excess of water at room temperature for one minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours and treated in fLowing air at 500F for two hours. i~
Example XVI
The catalyst of this example was, for three times: (1) treated for 30 minute at 165F in a ten-fold excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) then cooled and filtered. Then the cata-lyst was, ~or three times: (1) mixed with a ten-fold excess of a solution of 0.lN KOH, (2) treated with the KOH
solution for one hour at 135F, (3) cooled, and (4) fil-tered. Then the catalyst was treated with a ten-fold excess of deionized water at 135F, cooled, and filtered.
Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
'. , '`' , ,, '. '' J
~2572~5 Example XVII
The catalyst o this exa~ple was placed into a S quartz reactor tube in a ~urnace, then 1% oxygen in nitro-~en was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow o~ oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F. (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F in a ten-fold excess of a solution of O.lN sodium carbonate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F in a ten-fold excess of :-deionized water, (2), and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in ~~
flowing air at 500F for two hours.
Example XVIII
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1~ oxy~en in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at ~00F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst was, for three times: (1) treated for 30 minutes at 165F
with a ten-fold excess of an Aqueous solution of hydrogen chloride havin~ a pH of 3, (2) cooledr and (3) filtered.
Then the catalyst was, for three times: (1) treated for one hour at 135F with a seven-fold excess of a solution of O.lN sodium carbonate, (2) cooled, and (3) filtered.
Then the catalyst was, for three times: (1) treated at 135F for one hour with a seven-fold excess o~ deionized water, (2) cooled~ and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F or two hours.
. . , . ;. ........... . - .
. . .
~257~4s Table IV shows the further improvement obtain-able with preliminary treatment with an acidic solution.
Two pairs of data are shown, the first in each case treated with a neutral solution or no solution at all prior to treatment with the salt solution, the second in each case treated with an acidic solution first. In the di~ferences between the first pair of data and the second, note also the advantages of using pre-oxidation prior to the aqueous treatments, particularly if the acidic treat-ment step has been omitted.
TABLE III
-- :
The Effect of Acidic Wash Prior to Salt Wash Without Pre-Oxidation Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XV 27.53 82.13 22.61 8.42 65.~5 5.51 XVI 56.84 93.48 53.13 58.52 96.08 56.23 With Pre-Oxidation Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XVII 47.96 89. 29 42.82 41.77 91.84 38.36 ~`
XVIII 61.92 88.01 54.49 55.66 91.12 50.72 Example XI~
The catalyst of this example was heated to 176F
for two hours, and occasionally stirred, in the presence F
35 of a twenty-fold excess of an aqueous solution of 4 wt. %
KOH, then cooled and filtered. Then the catalyst was r for nine times: (1) mixed with a ten-fold excess of water at room temperature for one minute, (2~ allowed to settle for three minutes, and (3) filtered. At this point, the pE~ of ~2S7Z~5 the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours.
05 Example XX
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1~ oxygen in nitro-gen was passed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F for one 10 hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then, the catalyst was heated to 176F for two hours, and occasionally stirred, in the presence of a twenty-fold excess o~ an lS aqueous solution of 4 wt. % KOH, then cooled and filtered.
Then the catalyst was, for nine times: (1) mixed with a ten-fold excess of water at room temperature for one ! ' minute, (2) allowed to settle for three minutes, and (3) filtered. At this point, the pH of the effluent water was 7.5. Then the catalyst was dried in air at 250F for 20 hours.
Example XXI
The catalyst of this example was, for three times: (1) treated for 30 minutes at 165F with a ten-fold excess of an aqueous solution of hydrogen chloridehavin~ a pH of 3, (2) cooled, and (3) filtered. Then, the catalyst was, for three times (1) treated for one hour at 135F with an aqueous solution of 0.lN sodium carbonate, ~2) cooled, and ~3) filtered. Then the catalyst wasr for three times: (1) treated for one hour at 140F with a ten-fold excess of deionized water, (2) cooled and (3) fil-tered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Table V shows the importance of using a pre- -oxidation step. It sets forth pairs of data obtained with `~-and without this step. ~~
~57245 01 ~21-TABLE V
The Effect o Pre-Oxidation 1)5 Initial Final Example Conv. Sel. Mole 96 Conv. Sel~ Mole %
XIX 24.73 83.68 20069 18.86 82.67 15.59 XX 39.86 8~.53 35.29 31.31 89.29 27~95 - XXI 55.26 88.85 49. 3~ 49.88 92.90 46. 34 XVII 61.92 88.01 54.49 55.66 91.12 50.72 Example XXIIThe catalyst of this example was placed into a quartz reactor tube in a furnace, then 196 oxygen in nitrogen was ~assed over the catalyst at a rate of 2 cc/gram catalyst/min. The catalyst was treated at 600F
for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the catalyst was cooled to room temperature. Then the cata-lyst was, for three times: (1) treated for 30 minutes at 165F with a ten-fol(l excess of an aqueous solution of hydrogen chloride having a pH of 3, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated for one hour at 135F with a seven-fold excess of a solution of O.lN ma~nesium nitrate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated at 135F for one hour with a seven-fold excess of deionized water, ~2) cooled, and (3) filtered. Then 30 the catalyst was dried in air at 250F for two hours and treated in flowin~ air at 500F for two hours.
~ ` ;
The catalyst of this example was placed into a quartz reactor tube in a furnace, then 1% oxygen in nitro- ~@
35 gen was passed over the catalyst at a rate of 2 cc/grams catalyst/min. The catalyst was treated at 600F for one hour, then the catalyst was treated at 780F for five hours. The flow of oxygen was then stopped and the cata-lyst was cooled to room temperature. Then the catalyst r~
40 was, for three times: (1) treated with a ten-fold excess of deionized water for 30 minutes at 165F, (2) cooled, ~}`-tb~ r~
.
' ~
~2S7245:
-and filtered. Then the catalyst was, for three times:
tl) treated for one hour at 135F with a ten-fold excess of a solution of O.lN magnesium nitrate, (2) cooled, and (3) filtered. Then the catalyst was, for three times:
(1) treated ~or one hour at 140F with a ten-fold excess of deionized water, (2~ cooled, and (3) filtered. Then the catalyst was dried in air at 250F for two hours and treated in flowing air at 500F for two hours.
Finally, Table VI shows two unsuccessful treat-ments, one with a preliminary acidic treatment, and the other without.
TABLE VI
Initial Final Example Conv. Sel. Mole % Conv. Sel. Mole %
XXII 6.10 27.41 1~67 3.05 30.00 1~19 XXIII 5.78 21.82 1.26 Too low to calculate ~-While the present invention has been described with reference to specific embodiments, this application is intended to cover those changes which may be made by those skilled in the art without departing from the spirit and scope o~ the appended claims.
~0 .
Claims (15)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of rejuvenating a catalyst comprising contacting said catalyst with at least 10 cc of an aqueous media in the liquid phase per cc of catalyst: wherein said aqueous media is selected from the group consisting of water, an aqueous solution, and a saturated water vapor;
and wherein said catalyst comprises a large-pore zeolite containing at least one Group VIII metal.
and wherein said catalyst comprises a large-pore zeolite containing at least one Group VIII metal.
2. A method of rejuvenating a sulfur-contaminated catalyst that comprises a large-pore zeolite containing at least one Group VIII metal comprising:
(a) exposing said catalyst to oxidizing conditions in the presence of oxygen at a temperature of from about 200°C to about 450°C:
(b) contacting said oxidized catalyst with at least 500 cc of an aqueous media in the liquid phase per cc of catalyst; wherein said aqueous media is selected from the group consisting of water, an aqueous solution, and a saturated water vapor; to form a wet catalyst;
(c) exposing said wet catalyst to reducing condi-tions in the presence of hydrogen at a temperature of from about 200°C to about 700°C; and (d) repeating steps (a) through (c) until the cata-lyst is rejuvenated to the desired level.
(a) exposing said catalyst to oxidizing conditions in the presence of oxygen at a temperature of from about 200°C to about 450°C:
(b) contacting said oxidized catalyst with at least 500 cc of an aqueous media in the liquid phase per cc of catalyst; wherein said aqueous media is selected from the group consisting of water, an aqueous solution, and a saturated water vapor; to form a wet catalyst;
(c) exposing said wet catalyst to reducing condi-tions in the presence of hydrogen at a temperature of from about 200°C to about 700°C; and (d) repeating steps (a) through (c) until the cata-lyst is rejuvenated to the desired level.
3. A method of rejuvenating a sulfur-contaminated catalyst according to Claim 2 wherein said large-pore zeolite is a type L zeolite.
4. A method of rejuvenating a sulfur-contaminated catalyst according to Claim 2 wherein said aqueous media is a basic solution, and said catalyst is contacted with said basic solution at a temperature of from about 70°C to about 80°C.
5. A method of rejuvenating a catalyst and improving the stability of said catalyst, wherein said method comprises contacting said catalyst with an aqueous solution of a salt or hydroxide of a metal selected from the group consisting of an alkali metal and an alkaline earth metal, wherein said catalyst comprises a large-pore zeolite containing at least one Group VIII metal.
6. A method of rejuvenating a catalyst and improving the stability of said catalyst according to Claim 5 wherein said aqueous solution has a concentration of from 1% to 8% by weight of metal, and wherein there is from 2 to 30 cc of aqueous solution per gram of catalyst.
7. A method of rejuvenating a catalyst and improving the stability of said catalyst according to Claim 5 wherein said metal salt or hydroxide is potassium hydroxide.
8. A method of rejuvenating a catalyst and improving the stability of said catalyst according to Claim 5 wherein said contacting occurs at a temperature of from 25°C to 100°C.
9. A method of rejuvenating a catalyst and improving the stability of said catalyst according to Claim 5 wherein said catalyst that has been contacted with said aqueous solution is then washed with from 10 to 200 cc of water per gram of catalyst to remove excess metal.
10. A method of rejuvenating a catalyst and improving the stability of said catalyst according to Claim 5 wherein said large-pore zeolite is a type L
zeolite.
zeolite.
11. A method of rejuvenating a sulfur-contaminated catalyst and improving the stability of said catalyst, wherein said method comprises:
(a) contacting said catalyst at a temperature of about 80°C with an aqueous solution of potassium hydroxide, wherein said aqueous solution has a concentra-tion of from 1% to 8% by weight of metal, and wherein there is from 2 to 30 cc of aqueous solution per gram of catalyst;
(b) washing said catalyst with from 10 to 200 cc of water per gram of catalyst to remove excess metal;
(c) drying said washed catalyst; and wherein said catalyst comprises:
(A) a type L zeolite containing from 0.1% to 1.5% by weight platinum: and (B) an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays.
(a) contacting said catalyst at a temperature of about 80°C with an aqueous solution of potassium hydroxide, wherein said aqueous solution has a concentra-tion of from 1% to 8% by weight of metal, and wherein there is from 2 to 30 cc of aqueous solution per gram of catalyst;
(b) washing said catalyst with from 10 to 200 cc of water per gram of catalyst to remove excess metal;
(c) drying said washed catalyst; and wherein said catalyst comprises:
(A) a type L zeolite containing from 0.1% to 1.5% by weight platinum: and (B) an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays.
12. A method of rejuvenating a catalyst, wherein said method comprises:
(a) washing said catalyst with a solution selected from the group consisting of a neutral solution and an acidic solution:
(b) contacting said washed catalyst with an aqueous solution of a salt or hydroxide of a metal selected from the group consisting of an alkali metal and an alkaline earth metal;
(c) washing said contacted catalyst with a neutral solution; and (d) drying said twice washed catalyst: wherein said catalyst comprises a large pore zeolite containing at least one Group VIII metal.
(a) washing said catalyst with a solution selected from the group consisting of a neutral solution and an acidic solution:
(b) contacting said washed catalyst with an aqueous solution of a salt or hydroxide of a metal selected from the group consisting of an alkali metal and an alkaline earth metal;
(c) washing said contacted catalyst with a neutral solution; and (d) drying said twice washed catalyst: wherein said catalyst comprises a large pore zeolite containing at least one Group VIII metal.
13. A method of rejuvenating a catalyst according to Claim 12 wherein said metal salt or hydroxide is a potassium hydroxide.
14. A method of rejuvenating a catalyst according to Claim 12 wherein said large-pore zeolite is a type L
zeolite.
zeolite.
15. A method of rejuvenating a sulfur-contaminated catalyst, wherein said method comprises:
(a) contacting said catalyst with an oxidizing gas at conditions which favor oxidation;
(b) washing said catalyst with a solution selected from the group consisting of a neutral solution and an acidic solution:
(c) contacting said washed catalyst at a temperature of about 80°C with an aqueous solution of potassium hydroxide, wherein said aqueous solution of potassium hydroxide has a concentration of from 0.1% to 8% by weight of metal, and wherein there is from 2 to 30 cc of aqueous solution per gram of catalyst.
(d) washing said contacted catalyst of step (c) with from 10 to 200 cc of water per gram of catalyst to remove excess metal;
(e) drying said washed catalyst of step (d): and (f) contacting said dried catalyst with an oxidizing gas at conditions which favor oxidation; wherein said catalyst comprises:
(A) a type L zeolite containing from 0.1% to 1.5% by weight platinum; and (B) an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays.
(a) contacting said catalyst with an oxidizing gas at conditions which favor oxidation;
(b) washing said catalyst with a solution selected from the group consisting of a neutral solution and an acidic solution:
(c) contacting said washed catalyst at a temperature of about 80°C with an aqueous solution of potassium hydroxide, wherein said aqueous solution of potassium hydroxide has a concentration of from 0.1% to 8% by weight of metal, and wherein there is from 2 to 30 cc of aqueous solution per gram of catalyst.
(d) washing said contacted catalyst of step (c) with from 10 to 200 cc of water per gram of catalyst to remove excess metal;
(e) drying said washed catalyst of step (d): and (f) contacting said dried catalyst with an oxidizing gas at conditions which favor oxidation; wherein said catalyst comprises:
(A) a type L zeolite containing from 0.1% to 1.5% by weight platinum; and (B) an inorganic binder selected from the group consisting of silica, alumina, aluminosilicates, and clays.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US66948484A | 1984-11-08 | 1984-11-08 | |
| US66948784A | 1984-11-08 | 1984-11-08 | |
| US66948684A | 1984-11-08 | 1984-11-08 | |
| US669,486 | 1984-11-08 | ||
| US669,484 | 1984-11-08 | ||
| US669,487 | 1984-11-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1257245A true CA1257245A (en) | 1989-07-11 |
Family
ID=27418191
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000494758A Expired CA1257245A (en) | 1984-11-08 | 1985-11-07 | Rejuvenation of a deactivated catalyst |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0204750A4 (en) |
| KR (1) | KR870700404A (en) |
| AU (1) | AU5201686A (en) |
| CA (1) | CA1257245A (en) |
| DE (1) | DE3590575T1 (en) |
| GB (1) | GB2176716A (en) |
| NL (1) | NL8520394A (en) |
| WO (1) | WO1986002861A1 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4851380A (en) * | 1986-12-19 | 1989-07-25 | Chevron Research Company | Process for regenerating sulfur contaminated reforming catalysts |
| USRE34250E (en) * | 1986-12-19 | 1993-05-11 | Chevron Research And Technology Company | Process for regenerating sulfur contaminated reforming catalysts |
| GB2211756A (en) * | 1987-10-30 | 1989-07-12 | Shell Int Research | Process for the preparation of paraffinic hydrocarbons and of a catalyst for said process |
| US4994423A (en) * | 1990-05-25 | 1991-02-19 | Amoco Corporation | Process for regenerating spent heavy hydrocarbon hydroprocessing catalyst |
| US5270272A (en) * | 1992-05-26 | 1993-12-14 | Uop | Sulfur removal from molecular-sieve catalyst |
| US6521791B1 (en) * | 2001-11-09 | 2003-02-18 | Air Products And Chemicals, Inc. | Process for regenerating a monolith hydrogenation catalytic reactor |
| US8912108B2 (en) | 2012-03-05 | 2014-12-16 | Chevron Phillips Chemical Company Lp | Methods of regenerating aromatization catalysts |
| US8716161B2 (en) | 2012-03-05 | 2014-05-06 | Chevron Phillips Chemical Company | Methods of regenerating aromatization catalysts |
| US9387467B2 (en) | 2012-09-26 | 2016-07-12 | Chevron Phillips Chemical Company Lp | Aromatization catalysts with high surface area and pore volume |
| KR101369021B1 (en) * | 2012-10-25 | 2014-02-28 | 한국화학연구원 | Low temperature oxidation catalyst improved water-stability for removal of toxic gases |
| US10118167B2 (en) * | 2016-12-20 | 2018-11-06 | Chevron Phillips Chemical Company Lp | Methods for regenerating sulfur-contaminated aromatization catalysts |
| US10226761B2 (en) | 2016-12-20 | 2019-03-12 | Chevron Phillips Chemical Company, Lp | Aromatization catalyst preparation with alkali metal present during a washing step |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2225811A (en) * | 1938-10-31 | 1940-12-24 | Universal Oil Prod Co | Treatment of catalysts |
| US3450644A (en) * | 1966-11-15 | 1969-06-17 | Union Carbide Corp | Treatment of oxidatively regenerated molecular sieve catalysts |
| US3524822A (en) * | 1967-09-11 | 1970-08-18 | Sinclair Research Inc | Process for washing and removing catalyst fines from a bed of solid catalyst particles in a reactor |
| US3625865A (en) * | 1968-10-21 | 1971-12-07 | Chevron Res | Method of increasing hydrocracking activity and/or reducing hydrocracking activity decline rate of catalyst comprising layered crystalline clay-type aluminosilicate component |
| BE764917A (en) * | 1970-03-27 | 1971-09-27 | Mobil Oil Corp | Regeneration of zeolite hydrocarbon con-version catalysts |
| US3692692A (en) * | 1970-10-29 | 1972-09-19 | Union Oil Co | Rejuvenation of damaged zeolitesupported metal catalysts |
| CA1003392A (en) * | 1971-01-18 | 1977-01-11 | Harry E. Robson | Preparation of improved hydrocarbon conversion catalysts |
| US3849293A (en) * | 1971-03-05 | 1974-11-19 | Union Oil Co | Hydrocracking process utilizing rejuvenated catalyst |
| US4139433A (en) * | 1973-02-22 | 1979-02-13 | Union Oil Company Of California | Hydrocracking process with aqueous ammonia rejuvenated zeolite catalyst comprising non-zeolitic noble metal |
| US3943051A (en) * | 1974-05-17 | 1976-03-09 | Union Oil Company Of California | Hydrocarbon conversion processes utilizing rejuvenated zeolite catalysts |
| FR2323664A1 (en) * | 1975-09-10 | 1977-04-08 | Erap | PROCESS FOR DEHYDROCYCLIZATION OF ALIPHATIC HYDROCARBONS |
| US4107031A (en) * | 1976-09-16 | 1978-08-15 | Union Oil Company Of California | Hydrocracking process with reactivated catalyst |
| US4147660A (en) * | 1976-12-22 | 1979-04-03 | Osaka Gas Company, Ltd. | Method for reactivation of platinum group metal catalyst with aqueous alkaline and/or reducing solutions |
| FR2498477B1 (en) * | 1981-01-26 | 1986-06-27 | Inst Francais Du Petrole | NOVEL REGENERATION-REJUVENATION PROCESS FOR A ZEOLITHIC CATALYST CONTAINING A HYDROGENANT METAL |
| FR2512356B1 (en) * | 1981-09-09 | 1986-08-08 | Elf Aquitaine | PROCESS FOR REGENERATING AN AROMATIZATION CATALYST |
| US4447316A (en) * | 1982-02-01 | 1984-05-08 | Chevron Research Company | Composition and a method for its use in dehydrocyclization of alkanes |
| US4550090A (en) * | 1983-08-26 | 1985-10-29 | Mobil Oil Corporation | Regeneration of ZSM-5 type catalyst with a source of alkali or alkaline earth metal cations or ammonia |
-
1985
- 1985-11-07 GB GB08612723A patent/GB2176716A/en not_active Withdrawn
- 1985-11-07 AU AU52016/86A patent/AU5201686A/en not_active Abandoned
- 1985-11-07 NL NL8520394A patent/NL8520394A/nl unknown
- 1985-11-07 EP EP19850905984 patent/EP0204750A4/en not_active Withdrawn
- 1985-11-07 WO PCT/US1985/002218 patent/WO1986002861A1/en not_active Application Discontinuation
- 1985-11-07 CA CA000494758A patent/CA1257245A/en not_active Expired
- 1985-11-07 DE DE19853590575 patent/DE3590575T1/en not_active Withdrawn
-
1986
- 1986-06-11 KR KR1019860700348A patent/KR870700404A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0204750A1 (en) | 1986-12-17 |
| WO1986002861A1 (en) | 1986-05-22 |
| NL8520394A (en) | 1986-10-01 |
| DE3590575T1 (en) | 1986-11-20 |
| KR870700404A (en) | 1987-12-29 |
| EP0204750A4 (en) | 1987-12-02 |
| AU5201686A (en) | 1986-06-03 |
| GB2176716A (en) | 1987-01-07 |
| GB8612723D0 (en) | 1986-07-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1257245A (en) | Rejuvenation of a deactivated catalyst | |
| CA1310947C (en) | Process for regenerating a monofunctional large-pore zeolite catalyst having high selectivity for paraffin dehydrocyclization | |
| US4435283A (en) | Method of dehydrocyclizing alkanes | |
| US3945943A (en) | Zeolite containing compositions, catalysts and methods of making | |
| US4547472A (en) | Method of adding an alkaline earth metal to a zeolitic catalyst | |
| CA1332233C (en) | Reforming using a bound zeolite catalyst | |
| CA2104975A1 (en) | Low temperature regeneration of coke deactivated reforming catalysts | |
| US3692692A (en) | Rejuvenation of damaged zeolitesupported metal catalysts | |
| JPS60225646A (en) | New hydrogenating cracking or cracking catalyst of hydrocarbon charge | |
| JPS5857408B2 (en) | Method for producing aromatic hydrocarbons from aliphatic hydrocarbons | |
| US4539305A (en) | Pretreatment method for enhancing the selectivity and increasing the stability of a reforming catalyst | |
| US3943051A (en) | Hydrocarbon conversion processes utilizing rejuvenated zeolite catalysts | |
| US3326797A (en) | Hydrocarbon conversion process and catalyst comprising a crystalline alumino-silicate leached with sodium hydroxide | |
| US5106803A (en) | Reforming using a bound zeolite catalyst | |
| US4539304A (en) | Pretreatment method for increasing conversion of reforming catalyst | |
| US4002575A (en) | Rejuvenation of supported group VIII metal catalysts | |
| US4766099A (en) | Catalyst for oil hydrorefining or mild hydrocracking of heavy oil charges to produce middle distillates | |
| US4190553A (en) | Rejuvenation of damaged zeolite-supported metal catalysts | |
| US3835028A (en) | Hydrocracking process with rejuvenated catalyst | |
| US3899441A (en) | Rejuvenation of damaged zeolite-supported metal catalysts | |
| NZ207186A (en) | Process for activating an aluminosilicate zeolite | |
| US3496096A (en) | Regenerating a platinium-rhenium reforming catalyst | |
| US4645752A (en) | Hydrocracking catalyst and process for manufacturing the same | |
| US3259588A (en) | Reactivation of thermactivated catalyst | |
| US4405503A (en) | Production of zeolite agglomerates |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |