Process for increased olefin yields from heavy feedstocks
AssigneeExxon Chemical Patents Inc.
InventorsLarry Lee Iaccino, Nicolas P. Coute
Life of this patent
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Abstract
A process for upgrading petroleum feedstocks boiling in the distillate plus range, which feedstocks, when cracked, result in unexpected high yields of olefins. The feedstock is hydroprocessed in at least one reaction zone countercurrent to the flow of a hydrogen-containing treat gas. The hydroprocessed feedstock is then subjected to thermal cracking in a steam cracker or to catalytic cracking in a fluid catalytic cracking process. The resulting product slate will contain an increase in olefins compared with the same feedstock, but processed in by a conventional co-current hydroprocessing process.
Claims25
A process for increasing the yield of olefins from a gas oil boiling range feed stream during cracking which process comprises:
- (a) passing said feed stream to an initial countercurrent reaction zone wherein the feed stream flows countercurrent to upflowing hydrogen-containing treat gas, in the presence of one or more catalysts selected from the group consisting of hydrotreating catalysts, hydrogenation catalysts, hydrocracking catalysts, and ring-opening catalysts, wherein said initial countercurrent reaction zone has a non-reaction zone immediately upstream and immediately downstream therefrom;
- (b) recovering a vapor phase effluent from said reaction zone in the immediate upstream non-reaction zone, which vapor phase effluent contains hydrogen-containing treat gas, gaseous reaction products, and a vaporized liquid reaction product;
- (c) recovering downstream from said reaction zone a heavy liquid product;
- (d) passing the heavy liquid product to a cracking process unit which is selected from the group consisting of thermal cracking process units, and catalytic cracking process units wherein a vapor phase product stream is recovered comprising olefins;
- wherein there is provided at least a first co-current reaction zone, upstream of said initial countercurrent reaction zone, wherein said feed stream flows co-current to the flow of a hydrogen containing treat gas, wherein said first co-current reaction zone comprises a bed of hydrotreating catalyst and is operated under hydrotreating conditions.
A process for increasing the yield of olefins from a gas oil boiling range feed stream during cracking which process comprises:
- (a) passing said feed stream to an initial countercurrent reaction zone wherein the feed stream flows countercurrent to upflowing hydrogen-containing treat gas, in the presence of one or more catalysts selected from the group consisting of hydrotreating catalysts, hydrogenation catalysts, hydrocracking catalysts, and ring-opening catalysts, wherein said initial countercurrent reaction zone has a non-reaction zone immediately upstream and immediately downstream therefrom;
- (b) recovering a vapor phase effluent from said reaction zone in the immediate upstream non-reaction zone, which vapor phase effluent contains hydrogen-containing treat gas, gaseous reaction products, and a vaporized liquid reaction product;
- (c) recovering downstream from said reaction zone a heavy liquid product;
- (d) passing the heavy liquid product to a cracking process unit which is selected from the group consisting of thermal cracking process units, and catalytic cracking process units wherein a vapor phase product stream is recovered comprising olefins
- wherein said liquid phase reaction product is passed to one or more downstream cocurrent reaction zones comprising hydroprocessing catalysts operated at hydroprocessing conditions.
A process for increasing the yield of olefins from a gas oil boiling range feed stream during cracking which process comprises:
- (a) passing said feed stream to an initial countercurrent reaction zone wherein the feed stream flows countercurrent to upflowing hydrogen-containing treat gas, in the presence of one or more hydrocracking catalysts, wherein said initial countercurrent reaction zone has a non-reaction zone immediately upstream and immediately downstream therefrom;
- (b) recovering a vapor phase effluent from said reaction zone in the immediate upstream non-reaction zone, which vapor phase effluent contains hydrogen-containing treat gas, gaseous reaction products, and a vaporized liquid reaction product;
- (c) recovering downstream from said reaction zone a heavy liquid product;
- (d) passing the heavy liquid product to a cracking process unit which is selected from the group consisting of thermal cracking process units, and catalytic cracking process units wherein a vapor phase product stream is recovered comprising olefins;
- wherein there is provided at least a first co-current reaction zone, upstream of said initial countercurrent reaction zone, wherein said feed stream flows co-current to the flow of a hydrogen containing treat gas, wherein said first co-current reaction zone comprising a bed of hydrotreating catalyst and is operated under hydrotreating conditions;
- and
- wherein downstream of all reaction zones, said vaporized liquid reaction product is condensed and combined with said heavy liquid phase reaction product and sent to a cracking process unit.
Dependencies are inferred from the claim text.