Methods for deoxygenating biomass-derived pyrolysis oil

1. A method for deoxygenating a biomass-derived pyrolysis oil, the method comprising the steps of:

diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed; and

contacting the diluted pyoil-phenolic feed with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

2. The method of claim 1 , wherein the step of diluting comprises diluting the biomass-derived pyrolysis oil with the phenolic-containing diluent that comprises phenolic compounds present in an amount of about 25 wt. % or greater of the phenolic-containing diluent.

3. The method of claim 1 , wherein the step of diluting comprises diluting the biomass-derived pyrolysis oil with the phenolic-containing diluent that comprises phenolic compounds present in an amount of from about 50 to about 100 wt. % of the phenolic-containing diluent.

4. The method of claim 1 , wherein the step of diluting comprises forming the diluted pyoil-phenolic feed comprising the biomass-derived pyrolysis oil that is present in an amount of from about 10 to about 90 wt. % of the diluted pyoil-phenolic feed.

5. The method of claim 1 , wherein the step of diluting comprises diluting the biomass-derived pyrolysis oil with the phenolic-containing diluent that comprises a phenolic mixture derived from a biorenewable source including wood creosote.

6. The method of claim 1 , wherein the step of diluting comprises diluting the biomass-derived pyrolysis oil with the phenolic-containing diluent that comprises phenol, methylphenol, tert-butylphenol, trimethylphenol, dimethylphenol, dimethoxyphenol, cyclopentylphenol, ethylphenol, ethyl-methylphenol, methoxyphenol, methoxy-propylphenol, methyl-isopropylphenol, propylphenol, methyl-propylphenol, ethyl-methoxyphenol, methoxy-propenylphenol, dimethoxy-propenylphenol, or combinations thereof.

7. The method of claim 1 , wherein the step of diluting comprises diluting the biomass-derived pyrolysis oil with the phenolic-containing diluent that comprises phenol, methylphenol, trimethylphenol, dimethylphenol, ethylphenol, ethyl-methylphenol, or combinations thereof.

8. The method of claim 1 , wherein the step of contacting comprises contacting the diluted pyoil-phenolic feed at the hydroprocessing conditions that include a reactor temperature of from about 150 to about 500° C.

9. The method of claim 1 , wherein the step of contacting comprises contacting the diluted pyoil-phenolic feed at the hydroprocessing conditions that include a reactor pressure of from about 2.76 to about 20.7 MPa gauge.

10. The method of claim 1 , further comprising the step of:

separating and recycling a phenolic-containing portion from the low-oxygen biomass-derived pyrolysis oil effluent to form at least a portion of the phenolic-containing diluent.

11. A method for deoxygenating a biomass-derived pyrolysis oil, the method comprising the steps of:

combining a pyoil-containing stream that comprises the biomass-derived pyrolysis oil with a phenolic-containing diluent at a predetermined diluent ratio to form a diluted pyoil-phenolic feed stream, wherein the predetermined diluent ratio is defined by a diluent mass flow rate of the phenolic-containing diluent to a pyoil mass flow rate of the pyoil-containing stream; and

introducing the diluted pyoil-phenolic feed stream and a hydrogen-containing gas stream to a reactor that contains a deoxygenating catalyst and that is operating at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

12. The method of claim 11 , wherein the step of combining comprises combining the pyoil-containing stream with the phenolic-containing diluent at the predetermined diluent ratio of from about 1:10 to about 10:1.

13. The method of claim 11 , wherein the step of combining comprises combining the pyoil-containing stream with the phenolic-containing diluent that comprises a phenolic-containing diluent fresh feed stream.

14. The method of claim 11 , wherein the step of introducing comprises introducing the hydrogen-containing gas stream to the reactor such that the hydroprocessing conditions include a hydrogen-containing gas treat rate of from about 175 to about 2,700 SL H 2 /L feed.

15. The method of claim 11 , wherein the step of introducing comprises introducing the diluted pyoil-phenolic feed stream to the reactor such that the hydroprocessing conditions include a liquid hourly space velocity on a basis of volume of the biomass-derived pyrolysis oil per volume of catalyst of from about 0.1 to about 1 hr −1 .

16. The method of claim 11 , wherein the step of combining comprises introducing the pyoil-containing stream that has a temperature of from about 15 to about 50° C. to the phenolic-containing diluent.

17. The method of claim 11 , wherein the step of combining comprises introducing the pyoil-containing stream to the phenolic-containing diluent that has a temperature of from about 50 to about 150° C.

18. The method of claim 11 , further comprising the steps of:

introducing the low-oxygen biomass-derived pyrolysis oil effluent to a separation zone to separate a phenolic-containing portion from the low-oxygen biomass-derived pyrolysis oil effluent; and

recycling the phenolic-containing portion to form at least a portion of the phenolic-containing diluent.

19. The method of claim 18 , wherein the step of introducing the low-oxygen biomass-derived pyrolysis oil effluent comprises removing water.

20. A method for deoxygenating a biomass-derived pyrolysis oil, the method comprising the steps of:

separating a phenolic-containing diluent recycle stream from a low-oxygen biomass-derived pyrolysis oil effluent that was formed in a reactor that contains a deoxygenating catalyst and that is operating at hydroprocessing conditions effective for hydroprocessing the biomass-derived pyrolysis oil in the presence of hydrogen;

combining the phenolic-containing diluent recycle stream with a pyoil-containing stream that comprises the biomass-derived pyrolysis oil at a predetermined recycle ratio to form a diluted pyoil-phenolic feed stream, wherein the predetermined recycle ratio is defined by a recycle diluent mass flow rate of the phenolic-containing diluent recycle stream to a pyoil mass flow rate of the pyoil-containing stream, wherein the predetermined recycle ratio is from about 1:10 to about 10:1; and

introducing a hydrogen-containing gas stream and the diluted pyoil-phenolic feed stream to the reactor.