Conversion of lignin to fuels and aromatics

Patent metadata

Field	Value
Publication number	US-10196571-B2
Application number	US-201514876940-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Nov 20, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Methods are provided for converting lignin-containing biomass into compounds that are more readily processed to form fuel and/or chemical products. The methods can allow for removal of at least a portion of the oxygen in lignin, either during or after depolymerization of lignin to single ring aromatic compounds, while optionally reducing or minimizing aromatic saturation performed on the aromatic compounds. The methods can include use of quench solvent to control reactions within the product stream from a pyrolysis process and/or use of a solvent to assist with hydroprocessing of lignin, lignin-containing biomass, or a pyrolysis oil.

First claim

What is claimed is:

1. A method of converting lignin to aromatic compounds, comprising:
processing a lignin-containing feed under effective depolymerization conditions to form a depolymerized effluent containing monolignols;
mixing the depolymerized effluent with a solvent, wherein the solvent is in a liquid phase, has a T5 boiling point of at least about 240° C. and comprises at least about 50 wt % aromatic compounds; and
exposing at least a portion of the depolymerized effluent and solvent to a deoxygenation catalyst under effective deoxygenation conditions to form at least a deoxygenated effluent,
wherein the solvent comprises a recycled portion of the deoxygenated effluent.

2. The method of claim 1 , wherein processing a lignin-containing feed under effective depolymerization conditions comprises processing the lignin-containing feed under effective pyrolysis conditions in a pyrolysis reaction zone to form a pyrolysis effluent, the pyrolysis effluent exiting the pyrolysis reaction zone at an exit temperature.

3. The method of claim 2 , wherein mixing the depolymerized effluent with the solvent comprises:
mixing the pyrolysis effluent with a quench solvent, the quench solvent being at a quench solvent temperature and the pyrolysis effluent being at a mixing temperature that is less than about 100° C. different than the exit temperature; and
forming a liquid product comprising at least a portion of the pyrolysis effluent and the quench solvent, the weight ratio of quench solvent to pyrolysis oil effluent in the liquid product being at least about 1:1.

4. The method of claim 3 , wherein the quench solvent temperature is different from the mixing temperature of the pyrolysis effluent by about 100° C. or less.

5. The method of claim 3 , wherein the quench solvent temperature is different from the mixing temperature of the pyrolysis effluent by more than about 100° C.

6. The method of claim 5 , wherein the quench solvent is a liquid at the quench solvent temperature.

7. The method of claim 3 , wherein the quench solvent comprises about 5 wt % or less of compounds containing vinyl or allylic functional groups.

8. The method of any one of claims 1 - 4 , 5 , 6 or 7 wherein the deoxygenated effluent has an oxygen content of about 1 wt % or less.

9. The method of claim 8 , wherein the effective deoxygenation conditions comprise a temperature of about 200° C. to about 450° C. and a hydrogen partial pressure of about400 psig to about 1500 psig.

10. The method of claim 1 , further comprising exposing at least a portion of the deoxygenated effluent to a dealkylation catalyst under effective dealkylation conditions to form benzene.

11. The method of claim 10 , further comprising exposing at least a portion of the benzene to an alkylation catalyst and methanol under effective alkylation conditions to form xylene.

12. A method of converting lignin to aromatic compounds, comprising:
processing a lignin-containing feed under effective depolymerization conditions to form a depolymerized effluent containing monolignols;
mixing the depolymerized effluent with a solvent, wherein each of the depolymerized effluent and the solvent are in the gas phase, the solvent has a T5 boiling point of at least about 240° C. and comprises at least about 50 wt % of aromatic compounds;
exposing at least a portion of the depolymerized effluent containing monolignols and the solvent to a deoxygenation catalyst under effective deoxygenation conditions to form a deoxygenated effluent containing alkylated benzene compounds;
exposing at least a portion of the alkylated benzene compounds to a dealkylation catalyst under effective dealkylation conditions to form benzene; and
exposing at least a portion of the benzene to an alkylation catalyst and methanol under effective alkylation conditions to form xylene,
wherein the solvent comprises a recycled portion of the deoxygenated effluent.

13. The method of claim 12 , wherein the effective depolymerization conditions comprise pyrolysis conditions, the depolymerized effluent containing monolignols comprising a pyrolysis effluent.

14. The method of claim 13 , wherein the mixing is performed with the solvent being at a solvent temperature and the pyrolysis effluent being at a temperature that is less than about 100° C. different than a temperature of the pyrolysis effluent when exiting a pyrolysis reaction zone.

15. A method of converting lignin to aromatic compounds, comprising:
processing a lignin-containing feed under effective pyrolysis conditions to form a pyrolysis effluent containing monolignols;
mixing the pyrolysis effluent with a quench solvent, wherein the quench solvent is in a liquid phase, has a T5 boiling point of at least about 240° C. and comprises at least about 50 wt % of aromatic compounds; and
exposing at least a portion of the depolymerized effluent and quench solvent to a deoxygenation catalyst under effective deoxygenation conditions to form at least a deoxygenated effluent,
wherein a quench solvent temperature is different from a mixing temperature of the pyrolysis effluent by about 100° C. or less.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Lattner James R
• Xu Teng
• Keusenkothen Paul F

Classifications

• C10G3/42

  Catalytic treatment · CPC title

• C10B53/02

  of cellulose-containing material (production of pyroligneous acid C10C5/00) · CPC title

• C10K1/18

  hydrocarbon oils {(C10K1/165 takes precedence)} · CPC title

• Y02P30/20

  using bio-feedstock · CPC title

• C07C4/14

  splitting taking place at an aromatic-aliphatic bond · CPC title