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US4295997A Expired / Lapsed US ⏱️ 0.0 years remaining

SO2 Activation of supported chromium oxide catalysts

Assignee: Phillips Petroleum Co
•
Filing: 1980-02-28
•
Granted: 1981-10-20
•
Expires: 2000-02-28
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Abstract

Abstract A method for producing activated catalysts in which a catalyst containing chromium on a silica-containing support is (1) contacted with a gaseous environment consisting essentially of sulfur dioxde and oxygen at a temperature in a range of about 450° C. to about 1100° C. for a time ranging from about one to about five hours and (2) subsequently maintaining a temperature within the contact temperature range while contacting the catalyst with a gaseous environment consisting essentially of oxygen and gases inert to reaction with the catalyst. In another embodiment of the invention the temperature for a succeeding step is not raised above that attained in the previous step. In an embodiment of the invention the catalyst is contacted with a gaseous environment consisting essentially of oxygen and gases inert to reaction with the catalyst while the temperature is being increased prior to contact with sulfur dioxide.

Inventors

  • 👤 Max P. McDaniel
  • 👤 Melvin B. Welch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 02:34
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/24; B01J23/26; C; C08; C08F; C08F10/00

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 81 words
A method for producing an activated catalyst said method comprising: (1) contacting a catalyst comprising chromium on a silica-containing support with a gaseous environment consisting essentially of sulfur dioxide and oxygen at a temperature within a temperature range and for a time sufficient to activate the catalyst and subsequently (2) maintaining a temperature within the contact temperature range of step (1) while contacting said catalyst with a gaseous environment consisting essentially of oxygen and gases inert to reaction with the catalyst.
Claim 2
Independent Claim 81 words
A method for producing an activated catalyst said method comprising: (1) contacting a catalyst comprising chromium on a silica-containing support with a gaseous environment consisting essentially of sulfur dioxide and oxygen at a temperature within a temperature range and for a time sufficient to activate the catalyst and subsequently (2) maintaining a temperature within the contact temperature range of step (1) while contacting said catalyst with a gaseous environment consisting essentially of oxygen and gases inert to reaction with the catalyst.
Claim 3
Dependent Claim 38 words
A method of claim 1 wherein the catalyst is contacted with a gaseous environment consisting essentially of oxygen and gases inert to reaction with the catalyst while the temperature is being increased prior to contact with sulfur dioxide.
Claim 4
Dependent Claim 31 words
A method of claim 1 wherein the catalyst is contacted with a gaseous environment consisting essentially of sulfur dioxide and oxygen while the temperature is being increased to the activation range.
Claim 5
Dependent Claim 23 words
A method of claim 1, 2 or 3 wherein the temperature for step (b) is not raised above that attained in step (a).
Claim 6
Dependent Claim 25 words
A method of claim 1, 2 or 3 wherein the mole ratio of sulfur dioxide:oxygen is in the range of about 1:0.55 to about 1:10.
Claim 7
Dependent Claim 79 words
A method of claim 1, 2 or 3 wherein said gaseous environment consisting essentially of sulfur dioxide and oxygen is within a temperature range of about 450° to about 1100° C. (840° to 2000° F.), the contact time between the gaseous environment of sulfur dioxide and oxygen is in the range of about 1 to about 5 hours, and the total contact time between catalyst and gaseous environment is in the range of about 2 to about 20 hours.
Claim 8
Dependent Claim 34 words
A method of claim 6 wherein the contact between the catalyst and the gaseous environment of sulfur dioxide and oxygen is within a temperature range of about 540° to about 900° C. (1000°-1650° F.).
Claim 9
Dependent Claim 14 words
An activated catalyst produced by the method of claims 1, 2, 3 or 6.

References Cited (Backward Citations)

US3091605A Cited
US3037008A Cited
US3362946A Cited
US3780001A Cited
US4177162A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-10-19 1985-04-20 1985-10-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-10-19 1989-04-20 1989-10-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-10-19 1993-04-20 1993-10-20 $7700.00 Window Closed / Lapsed

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