Manufacture of renewable distillate from bio-oils
View Patent ↗Systems and methods are provided for hydroprocessing of bio-derived feeds, such as bio-oils and/or other types of feeds including triglycerides, fatty acids, and/or fatty acid derivatives. The systems and methods can assist with maintaining a desired temperature profile within a reactor while performing hydroprocessing on a feed with substantial oxygen content. In various aspects, the initial bed of the reactor can be exposed to 30 vol % or less of the total fresh feed. The remaining portions of the fresh feed can be introduced below one or more of the catalyst beds in the reactor. By reducing or minimizing the amount of fresh feed introduced upstream from the initial catalyst bed that contains a catalyst with hydrodeoxygenation activity, the net amount of product recycle can be reduced or minimized while still maintaining a target temperature profile across individual catalyst beds and/or across the reactor.
1. A method for performing hydrodeoxygenation, comprising:
exposing an undiluted first portion of a feedstock comprising 1.0 wt % or more of oxygen to a first hydroprocessing catalyst in a first catalyst bed in the presence of a hydrogen-containing treat gas under first hydroprocessing conditions to form a first liquid product effluent comprising 0.5 wt % or less of oxygen and a first gas product effluent, the undiluted first portion of the feedstock comprising 5.0 wt % to 30 wt % of the feedstock, wherein substantially no recycled liquid product stream is exposed to the first catalyst bed during a steady state operation;
cooling at least a portion of the first liquid product effluent;
exposing the cooled at least a portion of the first liquid product effluent, at least a portion of the first gas product effluent, and a second portion of the feedstock to a second hydroprocessing catalyst in a second catalyst bed under second hydroprocessing conditions to form a second liquid product effluent comprising 0.5 wt % or less of oxygen and a second gas product effluent;
cooling at least a portion of the second liquid product effluent; and
exposing the cooled at least a portion of the second liquid product effluent, at least a portion of the second gas product effluent, and a remaining portion of the feedstock to at least one additional hydroprocessing catalyst in at least one additional catalyst bed under at least one additional hydroprocessing condition to form a final liquid product effluent comprising 0.5 wt % or less of oxygen and a final gas product effluent.
2. The method of claim 1 , wherein a weighted average bed temperature of the first catalyst bed differs from a weighted average bed temperature of the second catalyst bed by 20° C. or less.
3. The method of claim 1 , wherein a temperature difference across the first catalyst bed is 60° C. or less, or wherein a temperature difference across the second catalyst bed is 60° C. or less, or a combination thereof.
4. The method of claim 1 , wherein the second portion of the feedstock comprises a higher weight percentage of the feedstock than the undiluted first portion of the feedstock.
5. The method of claim 1 , wherein exposing the remaining portion of the feedstock to hydroprocessing catalyst in at least one additional catalyst bed under at least one additional hydroprocessing condition comprises exposing a third portion of the feedstock to a third hydroprocessing catalyst in a third catalyst bed under third hydroprocessing conditions to form a third liquid product effluent and a third gas product effluent.
6. The method of claim 5 , wherein the third portion of the feedstock comprises a higher weight percentage of the feedstock than the undiluted first portion of the feedstock.
7. The method of claim 5 , wherein the weight percentage of the feedstock exposed to a catalyst bed is increased for three or more consecutive catalyst beds.
8. The method of claim 5 , the method further comprising:
cooling at least a portion of the third liquid product effluent;
exposing the cooled at least a portion of the third liquid product effluent, at least a portion of the third gas product effluent, and a fourth portion of the feedstock to a fourth hydroprocessing catalyst in a fourth catalyst bed under fourth hydroprocessing conditions to form a fourth liquid product effluent comprising 0.5 wt % or less of oxygen and a fourth gas product effluent.
9. The method of claim 5 , the method further comprising:
exposing an intermediate effluent comprising:
at least a portion of the third liquid product effluent and
at least a portion of the third gas product effluent
to a supplemental hydroprocessing catalyst in a supplemental catalyst bed under supplemental hydroprocessing conditions to form a fourth liquid product effluent comprising 0.5 wt % or less of oxygen and a fourth gas product effluent, the intermediate effluent comprising 0.0 wt % to 3.0 wt % of the feedstock relative to a weight of the feedstock.
10. The method of claim 9 , wherein the at least a portion of the third liquid product effluent comprises a cooled portion of the third liquid product effluent.
11. The method of claim 1 , wherein the cooled at least a portion of the first liquid product effluent comprises substantially all of the first liquid product effluent, or wherein the at least a portion of the first gas product effluent comprises substantially all of the first gas product effluent, or a combination thereof.
12. The method of claim 1 , wherein the first liquid product effluent is cascaded into a region above the second catalyst bed, or wherein the first gas product effluent is cascaded into a region above the second catalyst bed, or a combination thereof.
13. The method of claim 1 , wherein cooling at least a portion of the first liquid product effluent comprises quenching the at least a portion of the first liquid product with a hydrogen-containing quench gas, or wherein cooling at least a portion of the first liquid product effluent comprises passing the at least a portion of the first liquid product effluent through a heat exchanger, or a combination thereof.
14. The method of claim 1 , wherein cooling at least a portion of the first liquid product effluent comprises mixing the at least a portion of the first liquid product effluent with a recycle portion of the final liquid product effluent.
15. The method of claim 1 , wherein cooling at least a portion of the second liquid product effluent comprises quenching the at least a portion of the second liquid product with a hydrogen-containing quench gas, or wherein cooling at least a portion of the second liquid product effluent comprises passing the at least a portion of the second liquid product effluent through a heat exchanger, or a combination thereof.
16. The method of claim 1 , wherein cooling at least a portion of the second liquid product effluent comprises mixing the at least a portion of the second liquid product effluent with a recycle portion of the final liquid product effluent.
17. The method of claim 1 , wherein the first hydroprocessing conditions are different from the second hydroprocessing conditions, or wherein the first hydroprocessing catalyst is different from the second hydroprocessing catalyst, or a combination thereof.
18. The method of claim 1 , wherein the first hydroprocessing conditions comprise hydrodeoxygenation conditions, or wherein the first hydroprocessing catalyst comprises a hydrodeoxygenation catalyst, or a combination thereof.
19. The method of claim 1 , a) wherein the first hydroprocessing conditions comprises hydrotreating conditions, catalytic dewaxing conditions, aromatic saturation conditions, hydrodeoxygenation conditions, hydrocracking conditions, or a combination thereof; b) wherein the first hydroprocessing catalyst comprises a hydrotreating catalyst, a dewaxing catalyst, an aromatic saturation catalyst, a hydrodeoxygenation catalyst, a hydrocracking catalyst, or a combination thereof; or c) a combination of a) and b).
20. The method of claim 1 , wherein the feedstock comprises 50 wt % or more of a bio-derive fraction.