Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil

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

separating a low-oxygen biomass-derived pyrolysis oil effluent comprising phenolic compounds into a low-oxygen-pyoil organic phase stream and an aqueous phase stream at first separation conditions in which phenolic compounds in the low-oxygen biomass-derived pyrolysis oil effluent are miscible in the aqueous phase stream;

removing the phenolic compounds from the aqueous phase stream at second separation conditions in which the phenolic compounds are immiscible in the aqueous phase stream to form a phenolic-rich diluent recycle stream;

diluting and heating a biomass-derived pyrolysis oil stream with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream; and

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

2. The method of claim 1 , wherein the first separation conditions include a temperature of from about 60 to about 150° C.

3. The method of claim 1 , wherein the second separation conditions include a temperature of from about 10 to about 50° C.

4. The method of claim 1 , wherein the step of diluting and heating comprises diluting the biomass-derived pyrolysis oil stream with the phenolic-rich diluent recycle stream at a recycle ratio of from about 3:1 to about 10:1, wherein the recycle ratio is defined by a recycle mass flow rate of the phenolic-rich diluent recycle stream to a pyoil mass flow rate of the biomass-derived pyrolysis oil stream.

5. The method of claim 1 , wherein the step of diluting and heating comprises:

heating the phenolic-rich diluent recycle stream to form a heated phenolic-rich diluent recycle stream; and

combining the biomass-derived pyrolysis oil stream with the heated phenolic-rich diluent recycle stream to form the heated diluted pyoil feed stream.

6. The method of claim 1 , wherein the step of diluting and heating comprises:

combining the biomass-derived pyrolysis oil stream with the phenolic-rich diluent recycle stream to form a combined stream; and

heating the combined stream to form the heated diluted pyoil feed stream.

7. The method of claim 1 , wherein the hydroprocessing conditions include a reaction temperature of from about 260 to about 375° C.

8. The method of claim 1 , wherein the hydroprocessing conditions include a reactor pressure of from about 2 to about 20 MPa gauge.

9. The method of claim 1 , wherein the phenolic compounds comprise phenol, alkylphenols, phenol substituted compounds, or combinations thereof.

10. The method of claim 1 , wherein the low-oxygen biomass-derived pyrolysis oil effluent has a hydroprocessed organic phase comprising a residual oxygen content of from about 10 to about 20 wt. % of the hydroprocessed organic phase.

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

cooling and separating a low-oxygen biomass-derived pyrolysis oil effluent comprising phenolic compounds to form a low-oxygen-pyoil organic phase stream and a phenolic-containing aqueous phase stream;

cooling and separating the phenolic-containing aqueous phase stream to form a phenolic-rich diluent recycle stream and a water-rich stream;

diluting and heating a biomass-derived pyrolysis oil stream with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream; and

contacting the heated diluted pyoil feed stream with a deoxygenating catalyst in the presence of hydrogen in a hydroprocessing reactor at hydroprocessing conditions effective to deoxygenate the heated diluted pyoil feed stream to produce the low-oxygen biomass-derived pyrolysis oil effluent.

12. The method of claim 11 , wherein the step of cooling and separating the low-oxygen biomass-derived pyrolysis oil effluent comprises:

cooling the low-oxygen biomass-derived pyrolysis oil effluent with a first cooler to form a partially-cooled low-oxygen biomass-derived pyrolysis oil effluent; and

introducing the partially-cooled low-oxygen biomass-derived pyrolysis oil effluent to a first separator to form the low-oxygen-pyoil organic phase stream and the phenolic-containing aqueous phase stream.

13. The method of claim 12 , wherein the partially-cooled low-oxygen biomass-derived pyrolysis oil effluent has a temperature of from about 60 to about 150° C.

14. The method of claim 12 , further comprising a step of adding at least a portion of the water-rich stream to the low-oxygen biomass-derived pyrolysis oil effluent or the partially-cooled low-oxygen biomass-derived pyrolysis oil effluent prior to the step of contacting.

15. The method of claim 11 , wherein the step of cooling and separating the phenolic-containing aqueous phase stream comprises:

cooling the phenolic-containing aqueous phase stream with a second cooler to form a partially-cooled phenolic-containing aqueous phase stream; and

introducing the partially-cooled phenolic-containing aqueous phase stream to a second separator to form the phenolic-rich diluent recycle stream and the water-rich stream.

16. The method of claim 15 , wherein the partially-cooled phenolic-containing aqueous phase stream has a temperature of from about 10 to about 50° C.

17. The method of claim 11 , wherein the step of diluting and heating comprises:

heating the phenolic-rich diluent recycle stream to form a heated phenolic-rich diluent recycle stream having a first temperature of from about 285 to about 425° C.; and

combining the biomass-derived pyrolysis oil stream with the heated phenolic-rich diluent recycle stream to form the heated diluted pyoil feed stream having a second temperature of from about 260 to about 375° C.

18. The method of claim 11 , wherein the step of diluting and heating comprises:

combining the biomass-derived pyrolysis oil stream with the phenolic-rich diluent recycle stream to form a combined stream; and

heating the combined stream to form the heated diluted pyoil feed stream, wherein the heated diluted pyoil feed stream has a temperature of from about 260 to about 375° C.

19. The method of claim 11 , wherein the step of cooling and separating the low-oxygen biomass-derived pyrolysis oil effluent further comprises forming a H 2 -rich gas stream, and wherein the method further comprises a step of:

combining at least a portion of the H 2 -rich gas stream with the phenolic-rich diluent recycle stream prior to the step of diluting and heating.