Hydrocracker activity management

Abstract

In a hydrocracking process, the hydrocarbon feed is processed by a guard reactor operating at maximum severity temperatures. The processing in the guard reactor maximizes the removal of metals and performs hydrodenitrogenation steps and hydrodesulfurization steps. The demetallized and partially desulfurized and denitrogenized hydrocarbon feed is then sent to a treating reactor for further hydrodenitrogenation and hydrodesulfurization before being sent further downstream for further hydrocracking processing.

Claims

1. A process to increase demetallization, hydrodenitrogenation, and hydrodesulfurization of a hydrocarbon feedstock prior to hydrocracking, the process comprising: heating a guard reactor containing catalyst positioned therein to an elevated temperature exceeding about 700 degrees Fahrenheit; introducing a hydrocarbon feed containing a hydrocarbon feedstock into the guard reactor, wherein the elevated temperature of the guard reactor increases hydrocarbon feedstock metal penetration into pores of the guard reactor catalyst to increase demetallization of the hydrocarbon feedstock; operating the guard reactor to create at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock, wherein the elevated temperature of the guard reactor initially increases rates of hydrodenitrogenation and hydrodesulfurization of the hydrocarbon feedstock, such rates of hydrodenitrogenation and hydrodesulfurization gradually decreasing as the guard reactor catalyst is increasingly poisoned by hydrocarbon feedstock metals; passing the at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock to a treating reactor having catalyst positioned therein; operating the treating reactor to further denitrogenate and desulfurize the at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock to create a treated hydrocarbon feedstock, wherein life expectancy of the catalyst of the guard reactor is decreased to increase life expectancy of the catalyst of the treating reactor, thereby providing the treating reactor with an increased life span; and sending the treated hydrocarbon feedstock downstream for processing.

2. The process of claim 1 wherein the guard reactor provides hydrodenitrogenation and hydrodesulfurization at up to approximately 60% of treating reactor capacity, thereby providing longer operational cycles for the treating reactor.

3. The process of claim 1 wherein the sending the treated hydrocarbon feedstock downstream for process includes sending the treated hydrocarbon feedstock to a hydrocracking reactor.

4. The process of claim 1 wherein the hydrocarbon feedstock is gas oil.

5. The process of claim 1 wherein the hydrocarbon feedstock is a topped crude oil having a boiling range in excess of 400 degrees Fahrenheit.

6. The process of claim 1 wherein the hydrocarbon feedstock contains vanadium and nickel metals.

7. The process of claim 6 wherein the vanadium is present at between 10 to 1,000 parts per million by weight of feed.

8. The process of claim 6 wherein the nickel is present at between 5 to 500 parts by weight per million of feed.

9. The process of claim 1 wherein the hydrocarbon feedstock includes coke precursors.

10. A process to increase demetallization, hydrodenitrogenation, and hydrodesulfurization of a hydrocarbon feedstock prior to hydrocracking, the process comprising: heating a guard reactor containing catalyst positioned therein to an elevated temperature exceeding about 700 degrees Fahrenheit; introducing a hydrocarbon feedstock into the guard reactor, wherein the elevated temperature of the guard reactor increases hydrocarbon feedstock metal penetration into pores of the guard reactor catalyst to increase demetallization of the hydrocarbon feedstock; operating the guard reactor to create at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock, wherein the elevated temperature of the guard reactor initially increases rates of hydrodenitrogenation and hydrodesulfurization of the hydrocarbon feedstock, such rates of hydrodenitrogenation and hydrodesulfurization gradually decreasing as the guard reactor catalyst is increasingly poisoned by hydrocarbon feedstock metals; passing the at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock to a treating reactor having catalyst positioned therein; operating the treating reactor to further denitrogenate and desulfurize the at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock to create a treated hydrocarbon feedstock, wherein life expectancy of the catalyst of the guard reactor is decreased to increase life expectancy of the catalyst of the treating reactor, thereby providing the treating reactor with an increased life span; sending the treated hydrocarbon feedstock to a hydrocracking reactor; and hydrocracking the treated hydrocarbon feedstock.

11. The process of claim 10 wherein the guard reactor provides hydrodenitrogenation and hydrodesulfurization at up to approximately 60% of treating reactor capacity, thereby providing longer operational cycles for the treating reactor.

12. The process of claim 10 wherein the hydrocarbon feedstock contains vanadium metal and nickel metal.

13. The process of claim 12 wherein the vanadium metal is present at between 10 to 1,000 parts per million by weight of feed.

14. The process of claim 12 wherein the nickel metal is present at between 5 to 500 parts by weight per million of feed.

15. The process of claim 10 wherein the hydrocarbon feedstock is gas oil.

16. The process of claim 10 wherein the hydrocarbon feedstock is a topped crude oil having a boiling range in excess of 400 degrees Fahrenheit.

17. The process of claim 10 wherein the hydrocarbon feedstock includes coke precursors.

18. A process to increase demetallization, hydrodenitrogenation, and hydrodesulfurization of a hydrocarbon feedstock prior to hydrocracking, the process comprising: heating a guard reactor containing catalyst positioned therein to an elevated temperature that exceeds about 700 degrees Fahrenheit; introducing a hydrocarbon feedstock containing one or more metals into the guard reactor; operating the guard reactor at the elevated temperature to increase rates of hydrodenitrogenation and hydrodesulfurization of the hydrocarbon feedstock and to increase penetration of at least a portion of the one or more metals from the hydrocarbon feedstock into pores of the guard reactor catalyst, the rates of hydrodenitrogenation and hydrodesulfurization of the hydrocarbon feedstock decreasing as the at least a portion of the one or more metals collects in the pores of the guard reactor catalyst; passing at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock to a treating reactor having catalyst positioned therein; operating the treating reactor at a treating reactor temperature that is reduced from the elevated temperature to further denitrogenate and desulfurize the at least partially demetallized, denitrogenated, and desulfurized hydrocarbon feedstock and create a treated hydrocarbon feedstock, the elevated temperature of the guard reactor reducing life expectancy of the guard reactor catalyst as compared to life expectancy of the treating reactor catalyst; and sending the treated hydrocarbon feedstock downstream to a hydrocracker.

19. The process of claim 18, wherein the elevated temperature is near a maximum operating temperature of the guard reactor.

20. The process of claim 18, further comprising: operating the guard reactor at a pressure between about 100 psig and about 2,500 psig.

Description

IN THE DRAWINGS

(1) FIG. 1 is a schematic of the guard, treating and hydrocracking reactors containing multiple beds.

DETAILED DESCRIPTION OF THE DRAWING

(2) Hydrocarbon feedstock is transferred to a guard reactor 3 via supply lines 1 and 11. In the present application gas oil is the preferred feedstock. The guard reactor 3 is preheated to a temperature in excess of 700° F. Within the guard reactor, the feedstock is reacted with guard catalyst to remove metals. The elevated temperature of the guard reactor increases HDS and HDN activity within the guard reactor 3. HDN and HDS activity in the guard reactor results in less sulfur and nitrogen passing to the treating reactor 5. The HDS and HDN rate is highest within the guard reactor 3 during the start of a run, because there is little to no metal poisoning of the guard catalyst. As metal collects within the guard catalyst, the HDN and HDS rates in the guard reactor will decrease and more sulfur and nitrogen will pass to the treating reactor 5.

(3) The reduced sulfur and nitrogen feedstock is transferred from the guard reactor 3 to the treating reactors where the remaining HDS and HDN occurs. The treating reactor catalyst is used to remove the remaining sulfur and nitrogen. The HDN and HDS activity in the guard reactor 3 reduces the burden on the treating reactor 5 by performing some HDN and HSN prior to the feed entering the treating reactor 5. This increased HDN and HDS activity in the guard reactor 3 allows the treating reactor 5 to operate at less severe conditions and lengthens the life of the treating reactor catalyst, and therefore the treating reactor.

(4) The treated feedstock having reduced or eliminated metal, sulfur and nitrogen content is transferred from the treating reactor 5 to a hydrocracking reactor 7 for further processing.

(5) The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.