Reducing pressure drop buildup in bio-oil hydroprocessing reactors
A method is provided involving reducing a pressure drop across a hydroprocessing reactor having a reactor feed and producing a hydroprocessing product, where the reactor feed includes a bio-oil feed and a hydrocarbon diluent; and the step of reducing the pressure drop comprises stopping or substantially reducing the bio-oil feed supplied to the reactor and supplying the hydrocarbon diluent to the reactor with a mass flux of at least about 1,000 lb/hr/ft 2 .
1. A method comprising reducing a pressure drop across a hydroprocessing reactor having a reactor feed and producing a hydroprocessing product, wherein:
the reactor feed comprises a bio-oil feed and a hydrocarbon diluent at a volumetric ratio of hydrocarbon diluent to bio-oil feed from about 1:1 to about 3:1;
reducing the pressure drop is performed after a rate of pressure drop increase in the hydroprocessing reactor is about 0.1 psi/hr;
reducing the pressure drop comprises
supplying a volumetric ratio of hydrocarbon diluent to bio-oil feed of at least about 10:1 to the reactor to generate a mass flux of at least about 1,000 lb/hr/ft 2 ; and
re-establishing the volumetric ratio of hydrocarbon diluent to bio-oil feed from about 1:1 to about 3:1 once a rate of pressure drop decrease is below about 0.1 psi/hr.
2. The method of claim 1 , wherein the mass flux is from about 1,000 lb/hr/ft 2 to about 10,000 lb/hr/ft 2 .
3. The method of claim 1 , wherein the mass flux is at least about 2,000 lb/hr/ft 2 .
4. The method of claim 1 , wherein the hydrocarbon diluent comprises the hydroprocessing product of the hydroprocessing reactor.
5. The method of claim 1 , wherein reducing the pressure drop comprises supplying the hydrocarbon diluent to the hydroprocessing reactor at a volumetric ratio of at least 15:1 hydrocarbon diluent to bio-oil.
6. The method of claim 1 , wherein the hydrocarbon diluent is supplied at a temperature of about 400° F. to about 800° F.
7. The method of claim 1 , wherein the hydrocarbon diluent has a boiling point of about 300° F. to about 650° F.
8. The method of claim 1 , wherein the bio-oil comprises a lipid, a carboxylic acid, a plant oil, animal fat, algal oil, a distillate from the fermentation of sugars, or a liquid fraction derived from the fast pyrolysis of biomass.
9. The method of claim 8 , wherein the plant oil, animal fat, or both, contains nitrogen, sulfur, or phosphorus from about 0.1 wppm to about 30,000 wppm.
10. The method of claim 1 , wherein the bio-oil comprises a liquid fraction from the fast pyrolysis of biomass.
11. The method of claim 10 , wherein the liquid fraction is derived from ground wood, ground switch grass, or combinations thereof.
12. The method of claim 1 , wherein the hydroprocessing reactor comprises a graded bed.
13. The method of claim 12 , wherein the graded bed comprises high void and high macro-porosity media.
14. The method of claim 13 , wherein the graded bed comprises a catalyst comprising Co, Mo, Ni, Pt, Pd, Ru, W, NiMo, NiW, or CoMo.
15. The method of claim 1 , wherein the reactor feed further comprises hydrogen gas.
16. The method of claim 1 , wherein the hydroprocessing reactor performs at least some hydrodeoxygenation.
17. A method comprising reducing a pressure drop across a hydroprocessing reactor having a reactor feed, wherein:
the hydroprocessing reactor produces a hydroprocessing product;
the reactor feed is at a temperature from about 550° F. to about 750° F. and is produced by at least combining
a bio-oil feed at a temperature of about 100° F. to about 350° F.; and
a recycled hydroprocessing product of the hydroprocessing reactor at a temperature of about 550° F. to about 800° F.;
wherein the volumetric ratio of recycled hydroprocessing product to bio-oil feed is from about 1:1 to about 3:1;
reducing the pressure drop is performed after the theoretical void fraction drops below 26% and comprises
supplying a volumetric ratio of recycled hydroprocessing product to bio-oil feed of at least about 10:1 to the reactor to generate a mass flux of at least about 2,000 lb/hr/ft 2 ; and
re-establishing the volumetric ratio of hydrocarbon diluent to bio-oil feed from about 1:1 to about 3:1 once a decrease in pressure drop is in the range from about 10% to about 99%.
18. A method comprising reducing a pressure drop across a hydroprocessing reactor having a reactor feed and producing a hydroprocessing product, wherein:
the reactor feed comprises
a bio-oil feed and a hydrocarbon diluent at a volumetric ratio of hydrocarbon diluent to bio-oil feed from about 1:1 to about 3:1; and
the bio-oil comprises a plant oil, animal fat, or both;
reducing the pressure drop is performed after a rate of pressure drop increase in the hydroprocessing reactor is about 0.1 psi/hr;
reducing the pressure drop comprises
stopping the reactor feed to the hydroprocessing reactor and supplying the hydrocarbon diluent to the hydroprocessing reactor to generate a mass flux of about 1,000 lb/hr/ft 2 to about 10,000 lb/hr/ft 2 ; and
re-establishing the supply of reactor feed once a decrease in pressure drop is in the range from about 10% to about 99%.
19. The method of claim 18 , wherein the hydrocarbon diluent comprises the hydroprocessing product of the hydroprocessing reactor.
20. The method of claim 18 , wherein the hydrocarbon diluent is supplied at a temperature of about 400° F. to about 800° F. and has a boiling point of about 300° F. to about 650° F.
21. The method of claim 18 , wherein the hydroprocessing reactor comprises a graded bed; and the graded bed comprises a comprises a NiMo catalyst, a CoMo catalyst, or a combination thereof.
22. The method of claim 18 , wherein reducing the pressure drop comprises re-establishing the supply of reactor feed once the decrease in pressure drop is in the range from about 25% to about 80%.
23. The method of claim 18 , wherein the mass flux is from about 2,000 lb/hr/ft 2 to about 10,000 lb/hr/ft 2 .