Abstract There is disclosed a method for reactivating a fixed bed of used platinum group metal-alumina catalyst of the type in which the alumina is derived from hydrous alumina predominating in alumina trihydrate. Such catalysts are employed in, for instance, the catalytic reforming of gasoline boiling range hydrocarbons to obtain fuels of high-octane ratings or aromatics. The method for reactivating the catalyst which has declined in activity during use and contains carbonaceous deposits, involves treating the deactivated catalyst at elevated temperatures with an oxygencontaining gas to burn the carbonaceous deposits therefrom. The relatively carbon-free catalyst is contacted under controlled conditions with a gaseous stream containing small amounts of chlorine, in combined or elemental form, oxygen and often water vapor to deposit chloride in a first portion of the catalyst bed. After the chlorine component is added to the catalyst, preferably in a relatively short period of time, the catalyst is then contacted with a gaseous stream containing oxygen and water vapor. This treatment may continue for a longer time than the chlorine treating period and until the chloride deposited on the catalyst is distributed through a major portion of the catalyst bed. Distribution of the chloride is a function of the time, temperature and water vapor partial pressure observed during the treatment and thus the distribution is controlled essentially by kinetics. The extent of water contact with the catalyst is limited by controlling the amount of water in the gaseous streams and the length of the overall treatment.
Inventors
👤 Marvin F L Johnson
👤 Stuart L Graff
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-01 10:27
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/90; B01J23/96
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
54 words
The method of claim 1 wherein the catalyst is deactivated by use in reforming gasoline boiling range hydrocarbons at a reactor inlet temperature of about 875* to 975* F. and a total pressure of about 200 to 500 pounds and the product has an octane rating of at least about 90 research octane numbers.
Claim 2
Dependent Claim
17 words
The method of claim 2 wherein the temperatures of said contactings are about 800* to 950* F.
Claim 3
Dependent Claim
43 words
The method of claim 1 in which the gaseous stream containing the chlorine-containing agent has a water to chlorine mole ratio of at least about 1:1 and the water vapor content of the gaseous stream is at least about 500 p.p.m. by volume.
Claim 4
Dependent Claim
44 words
The method of claim 4 on which the gaseous streams have an oxygen partial pressure of about 0.5 to 5 p.s.i.a., and the length of the contact with the gaseous stream to which no chlorine-containing material is added is at least about 4 hours.
Claim 5
Dependent Claim
53 words
The method of claim 5 wherein the catalyst is deactivated by use in reforming gasoline boiling range hydrocarbons at a reactor inlet temperature of about 875* to 975* and a total pressure of about 200 to 500 pounds and the product has an octane rating of at least about 90 research octane numbers.
Claim 6
Dependent Claim
21 words
The method of claim 5 wherein the temperatures of said chloride addition and distribution steps are about 800 to 950* F.
Claim 7
Dependent Claim
27 words
The method of claim 6 in which the catalyst contacted with the chlorine-containing agent has a surface area of about 150 to 250 square meters per gram.
Claim 8
Dependent Claim
13 words
The method of claim 8 in which the chlorine-containing agent is carbon tetrachloride.
Claim 9
Dependent Claim
21 words
The method of claim 9 wherein the temperatures of said chloride addition and distribution steps are about 800* to 950* F.