Hydroprocessing process using uneven catalyst volume distribution among catalyst beds in liquid-full reactors
View Patent ↗The present invention provides a process for hydroprocessing hydrocarbons with uneven catalyst volume distribution among two or more catalyst beds. The process operates as a liquid-full process, wherein all of the hydrogen dissolves in the liquid phase. Hydrocarbons can be converted in the process to provide a liquid product including clean fuels with multiple desired properties such as low density and high cetane number.
1. A process for hydroprocessing a hydrocarbon feed, which comprises
(a) providing two or more catalyst beds disposed in sequence and in liquid communication, wherein each catalyst bed is a fixed bed and contains a catalyst having a catalyst volume, the catalyst volume increasing in each subsequent catalyst bed;
(b) contacting the feed with (i) a diluent and (ii) hydrogen, to produce a feed/diluent/hydrogen mixture, wherein the hydrogen is dissolved in the mixture to provide a liquid feed;
(c) contacting the feed/diluent/hydrogen mixture with a first catalyst in a first catalyst bed, to produce a product effluent;
(d) contacting a product effluent with a final catalyst in a final catalyst bed, to produce a final product effluent, wherein the product effluent contacted with the final catalyst is the product effluent from the catalyst bed immediately prior to the final catalyst bed;
wherein each contacting step of step (c) and step (d) is performed under liquid-full reaction conditions;
wherein the process is characterized by higher sulfur and nitrogen conversion as compared to an even catalyst volume distribution with the same catalyst and the same volume catalyst;
and wherein a ratio of the volume of the first catalyst to the volume of the final catalyst is in the range of about 1:1.1 to about 1:10.
2. The process of claim 1 wherein a distribution of the catalyst volumes among the catalyst beds is determined in a way so that the hydrogen consumption for each catalyst bed is essentially equal.
3. The process of claim 1 further comprises (e) recycling a portion of the final product effluent as a recycle product stream for use in the diluent in step (b)(i) at a recycle ratio of from about 0.1 to about 10.
4. The process of claim 3 wherein the recycle ratio is from about 0.1 to about 6.
5. The process of claim 4 wherein the recycle ratio is from about 0.1 to about 1.
6. The process of claim 1 wherein the hydrocarbon feed is mineral oil, synthetic oil, petroleum fractions, or combinations of two or more thereof.
7. The process of claim 6 wherein the hydrocarbon feed is selected from the group consisting of jet fuel, kerosene, straight run diesel, light cycle oil, light coker gas oil, gas oil, heavy cycle oil, heavy coker gas oil, heavy gas oil, resid, deasphalted oil, and combinations of two or more thereof.
8. The process of claim 1 wherein each catalyst bed has a temperature from about 204° C. to about 450° C., and a pressure from about 3.45 MPa (34.5 bar) to 17.3 MPa (173 bar), and a hydrocarbon feed rate to provide a liquid hourly space velocity (LHSV) of from about 0.1 to about 10 hr −1 .
9. The process of claim 1 wherein each catalyst bed has a temperature from about 300° C. to about 450° C., and a pressure from about 3.45 MPa (34.5 bar) to 17.3 MPa (173 bar), and a hydrocarbon feed rate to provide a liquid hourly space velocity (LHSV) of from about 0.4 to about 8 hr −1 .
10. The process of claim 1 wherein the diluent is selected from the group consisting of recycle product stream, light hydrocarbons, light distillates, naphtha, diesel, propane, butane, pentane, hexane and combinations thereof.
11. The process of claim 1 wherein at least one catalyst is a hydrotreating catalyst.
12. The process of claim 1 wherein at least one catalyst is a hydrocracking catalyst.
13. The process of claim 1 wherein each catalyst is a hydrotreating catalyst.
14. The process of claim 1 wherein each catalyst is a hydrocracking catalyst.
15. The process of claim 1 wherein one or more catalyst beds which contain a hydrotreating catalyst are followed by one or more catalyst beds which contain a hydrocracking catalyst.
16. The process of claim 1 wherein each catalyst comprises a metal which is a combination of metals selected from the group consisting of nickel-molybdenum (NiMo), cobalt-molybdenum (CoMo), nickel-tungsten (NiW) and cobalt-tungsten (CoW).
17. The process of claim 16 wherein each catalyst is sulfided.
18. The process of claim 1 wherein each catalyst is a hydrotreating catalyst or a hydrocracking catalyst and each catalyst comprises a metal and an oxide support wherein the metal is a non-precious metal.
19. The process of claim 1 wherein fresh hydrogen is added at the inlet of each catalyst bed.
20. The process of claim 1 wherein there is no separation of ammonia, hydrogen sulfide and remaining hydrogen from the product effluent from the first catalyst bed or the product effluent from a preceding catalyst bed prior to feeding the product effluent to a subsequent catalyst bed.
21. The process of claim 4 wherein the portion of the final product effluent is recycled without separating ammonia and hydrogen sulfide and remaining hydrogen from the final product effluent.
22. The process of claim 1 wherein ammonia and hydrogen sulfide are removed from at least a portion of a product effluent before the product effluent is contacted with a subsequent catalyst.
23. The process of claim 3 wherein hydrogen is recycled with the recycle product stream.