Catalyst – solid sorbent – or support therefor: product or process – Regenerating or rehabilitating catalyst or sorbent – Gas or vapor treating
Reexamination Certificate
2002-06-20
2003-07-15
Langel, Wayne A. (Department: 1754)
Catalyst, solid sorbent, or support therefor: product or process
Regenerating or rehabilitating catalyst or sorbent
Gas or vapor treating
C208S139000, C208S140000, C208S137000, C208S134000
Reexamination Certificate
active
06593264
ABSTRACT:
This invention relates to the regeneration and activation of reforming catalysts and the use of such activated catalysts in the reforming of hydrocarbons.
BACKGROUND OF THE INVENTION
Catalytic reforming, or hydroforming, is a well established industrial process employed by the petroleum industry for improving the octane quality of naphthas or straight run gasolines. In reforming, a multi-functional catalyst is employed which typically contains a metal hydrogenation-dehydrogenation (hydrogen transfer) component or components, such as Group VIII or Group VIIB metals, substantially atomically dispersed upon the surface of a porous inorganic oxide support, notably alumina.
In a conventional reforming process, a series of reactors constitute the heart of the reforming unit. Each reforming reactor is generally provided with a fixed bed or beds of the catalyst which receive upflow or downflow feed. Each reactor is provided with a heater because the reactions which take place therein are endothermic. In a conventional reforming process, a naphtha feed with hydrogen or hydrogen recycle gas is passed through a preheat furnace, then downward through a reactor, and then in sequence through subsequent interstage heaters and reactors of the series. The product of the last reactor is separated into a liquid fraction and a vaporous effluent. The vaporous effluent, a gas rich in hydrogen, is often used as hydrogen recycle gas in the reforming process.
During operation, the activity of the reforming catalyst gradually declines due to the build-up of coke, and the temperature of the process is gradually raised to compensate for the activity loss caused by the coke deposits. Eventually, economics dictate the necessity of regenerating the catalyst.
The initial phase of catalyst regeneration is accomplished by burning the coke off the catalyst under controlled conditions. Catalyst regeneration is then completed through a sequence of activation steps wherein the agglomerated metal hydrogenation-dehydrogenation components are atomically redispersed. Such activation generally is achieved by treating the catalyst with hydrogen to effect reduction of the metal oxide(s) present in the catalyst system, followed by a halogen treatment of the reduced catalyst system prior to placing it back into use.
In addition to the activation process required when working with a catalyst which has been subjected to regeneration by burning off coke from the catalyst, there is generally carried out an activation treatment of the initially charged catalyst to the reactor prior to the introduction of hydrocarbon feed to the system.
In both the activation of fresh catalyst as well as the activation of a regenerated catalyst there have been numerous efforts to achieve a catalyst system whereby the catalyst will have increased activity and increased catalyst life.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for the regeneration and activation of a reforming catalyst.
Another object of the invention is to provide an improved process for the regeneration and activation of a reforming catalyst whereby the catalyst activity is increased.
A still further object of this invention is to provide an improved process for the regeneration and activation of a reforming catalyst whereby the catalyst life is increased.
In accordance with one aspect of the present invention, a process for activating a catalyst is provided and comprises the steps of:
a) continuously flowing a reducing gas over the catalyst for contact with the catalyst;
(b) during step a), flowing a halogen-containing compound over the catalyst for contact with the catalyst for a first time period, wherein the first time period is greater than about 1 minute, and wherein the first time period is less than about 60 minutes; and
(c) following step b), and during step a), substantially discontinuing the flow of the halogen-containing compound over the catalyst for a second time period, wherein the second time period is greater than about 1 minute.
In accordance with another aspect of the present invention, a process for activating a catalyst is provided and comprises the steps of:
a) providing an activation zone containing water, an iron oxide, and a catalyst comprising at least one metal oxide selected from the group consisting of a Group VIII metal oxide, a Group VIIB metal oxide, tin oxide, germanium oxide, copper oxide, selenium oxide and combinations thereof;
b) removing at least a portion of the water from the activation zone;
c) reducing the iron oxide in the presence of a first reducing gas thereby forming reduced iron and a first produced water;
d) removing at least a portion of the first produced water from the activation zone;
e) reducing the at least one metal oxide of the catalyst by continuously flowing a second reducing gas over the catalyst for contact with the catalyst; thereby forming at least one reduced metal and a second produced water;
f) removing at least a portion of the second produced water from the activation zone;
(g) during step e), flowing a halogen-containing compound over the catalyst for contact with the catalyst for a first time period, wherein the first time period is greater than about 1 minute, and wherein the first time period is less than about 60 minutes; and
(h) following step g), and during step e), substantially discontinuing the flow of the halogen-containing compound over the catalyst for a second time period, wherein the second time period is greater than about 1 minute.
In accordance with another aspect of the present invention, a process for activating a catalyst is provided and comprises the steps of:
a) heating a catalyst in an activation zone to a temperature in the range of from about 100 to about 600° F., wherein the catalyst comprises at least one metal oxide selected from the group consisting of a Group VIII metal oxide, a Group VIIB metal oxide, tin oxide, germanium oxide, copper oxide, selenium oxide and combinations thereof;
b) withdrawing water from the activation zone during the heating of step a);
c) heating the catalyst in the activation zone and in the presence of a first reducing gas to a temperature in the range of from about 650 to about 840° F., thus producing a first produced water, at a first point in time at which the rate of water withdrawal in step b) from the activation zone is below about 0.00004 gallon of water per pound of the catalyst in the activation zone;
d) withdrawing at least a portion of the first produced water from the activation zone during the heating of step c);
e) heating the catalyst in the activation zone to a temperature in the range of from about 850 to about 940° F. and continuously flowing a second reducing gas over the catalyst for contact with the catalyst, thus producing a second produced water, at a second point in time at which the rate of the first produced water withdrawal in step d) from the activation zone is below about 0.00004 gallon of water per pound of the catalyst in the activation zone;
f) withdrawing at least a portion of the second produced water from the activation zone during the heating of step e);
g) maintaining the temperature of the catalyst in the activation zone in the range of from about 850 to about 940° F. until a third point in time at which the rate of the second produced water withdrawal in step f) is below about 0.00004 gallon of water per pound of the catalyst in the activation zone;
h) during step e), flowing a halogen-containing compound over the catalyst for contact with the catalyst for a first time period, wherein the first time period is greater than about 1 minute, and wherein the first time period is less than about 60 minutes; and
i) following step h), and during step e), substantially discontinuing the flow of the halogen-containing compound over the catalyst for a second time period, wherein the second time period is greater than about 1 minute.
Other aspects, objects and the several advantages of the invention will be apparent from the following description and appended claims.
DETAILED DESCRIPTI
Limoges Brian H.
Lin Fan-Nan
Macahan Donald H.
Parsons John S.
Anderson Jeffrey R.
ConocoPhillips Company
Langel Wayne A.
Strickland Jonas N.
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