Desulfurization and novel compositions for same
View Patent ↗A composition comprising a metal oxide, a silica-containing material, a gallium-containing material, an aluminum-containing material, and a promoter, wherein at least a portion of the promoter is present as a reduced-valence promoter and methods of preparing such composition are disclosed. The thus-obtained composition is employed in a desulfurization zone to remove sulfur from a hydrocarbon stream.
1. A process for the removal of sulfur from a hydrocarbon stream comprising:
(a) contacting said hydrocarbon stream with a composition consisting of a metal oxide, a silica-containing material, an aluminum-containing material selected from the group consisting of alumina, aluminate, and combinations thereof, a gallium-containing material, and a promoter metal wherein at least a portion of said promoter metal is present as a reduced valence promoter and in an amount which will effect the removal of sulfur from said hydrocarbon stream in a desulfurization zone under conditions such that there is formed a desulfurized hydrocarbon stream and a sulfurized composition;
(b) separating said desulfurized hydrocarbon stream from said sulfurized composition thereby forming a separated desulfurized hydrocarbon stream and a separated sulfurized composition;
(c) regenerating at least a portion of said separated sulfurized composition in a regeneration zone so as to remove at least a portion of the sulfur contained therein and/or thereon thereby forming a regenerated composition;
(d) reducing said regenerated composition in an activation zone so as to provide a reduced composition having a reduced valence promoter metal content therein which will effect the removal of sulfur from a hydrocarbon stream when contacted with same; and thereafter
(e) returning at least a portion of said reduced composition to said desulfurization zone.
2. A process in accordance with claim 1 wherein said hydrocarbon stream comprises a fuel selected from the group consisting of cracked-gasoline, diesel fuel, and combinations thereof.
3. A process in accordance with claim 1 wherein said desulfurization in step (a) is carried out at a temperature in the range of from about 37.8° C. to about 537.8° C. and a pressure in the range of from about 15 to about 1500 psia for a time sufficient to effect the removal of sulfur from said stream.
4. A process in accordance with claim 1 wherein said regeneration in step (c) is carried out at a temperature in the range of from about 37.8° C. to about 815.5° C. and a pressure in the range of from about 10 to about 1500 psia for a time sufficient to effect the removal of at least a portion of the sulfur from said separated sulfurized composition.
5. A process in accordance with claim 1 wherein air is employed in step (c) as a regeneration agent in said regeneration zone.
6. A process in accordance with claim 1 wherein said regenerated composition from step (c) is subjected to reduction with hydrogen in step (d) in said reduction zone which is maintained at a temperature in the range of from about 37.8° C. to about 815.5° C. and at a pressure in the range of from about 15 to about 1500 psia and for a period of time sufficient to effect a reduction of the valence of the promoter content of said regenerated composition.
7. A process in accordance with claim 1 wherein said separated sulfurized composition from step (b) is stripped prior to introduction into said regeneration zone in step (c).
8. A process in accordance with claim 1 wherein said regenerated composition from step (c) is stripped prior to introduction to said reduction zone in step (d).