Stripping of regenerated catalyst during start-up and shutdown
AssigneeUop LLC
InventorsJohn J. Senetar, Richard A. Johnson, II
Life of this patent
Estimating the term…
Abstract
A process for preventing hazardous conditions at startup and shutdown of a reactor by sending an inert gas such as nitrogen to strip entrained oxygen from the catalyst when reactor temperatures are below about 240° C. During normal operation the entrained oxygen reacts with hydrocarbons to produce oxides but at the lower temperatures that are present at startup or shutdown these reactions do not occur sufficiently leaving oxygen that can cause hazardous conditions as temperatures increase upon startup. When the temperature is in the safe operating zone above 240° C., the nitrogen gas is stripped by air or other oxygen containing gas.
Claims20
A process for regenerating a catalyst comprising gallium comprising:
- combusting fuel gas with oxygen in the presence of the catalyst to provide a regenerated catalyst, and then stripping entrained oxygen from the catalyst by exposure of said catalyst to a stripping gas comprising an inert gas during startup or shutdown operations when the catalyst is at a temperature below about 400° C.
A process for regenerating a catalyst comprising noble metal and gallium comprising:
- feeding a stream of coked catalyst to a regenerator vessel;
- feeding a stream of oxygen supply gas to said regenerator vessel;
- feeding a stream of fuel gas to said regenerator vessel;
- combusting coke from said coked catalyst and combusting said fuel gas with said oxygen supply gas to provide a regenerated catalyst and flue gas;
- separating said regenerated catalyst from said flue gas
- and during periods of startup or shutdown stripping entrained oxygen on said regenerated catalyst by contacting said regenerated catalyst with an inert gas.
A process for operation of a of a paraffin dehydrogenation reactor containing a regenerated dehydrogenation catalyst comprising sending nitrogen gas into said paraffin dehydrogenation reactor when temperatures within said reactor are below about 400° C. and then purging said nitrogen gas when temperatures within said reactor exceed 400° C.
Dependencies are inferred from the claim text.