Solvolysis process

Patent metadata

Field	Value
Publication number	US-11987759-B2
Application number	US-202218083698-A
Country	US
Kind code	B2
Filing date	Dec 19, 2022
Priority date	Dec 23, 2021
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

The present disclosure relates to the thermal liquefaction of lignin, and more particularly to lignin solvolysis of a lignin feedstock chosen based on its molecular weight. The process comprises subjecting a feed mixture ( 30 ) of lignin feedstock ( 10 ) and solvent ( 20 ) to a thermal liquefaction step by heating ( 110 ) the feed mixture ( 30 ) at a temperature between 360 and 420° C., separating ( 120 ) a liquid product mix ( 50 ) from a product mix ( 40 ); and recirculating at least part of said liquid product mix ( 50 ) as an oil fraction of said solvent ( 20 ).

First claim

The invention claimed is:

1. A process for converting lignin to renewable liquid product(s), characterized in that the process comprises the following steps,
(a) treating a feed mixture ( 30 ) of lignin feedstock ( 10 ) and solvent ( 20 ) in a thermal liquefaction step by heating ( 110 ) the feed mixture ( 30 ) at a temperature between 360 and 420° C., under a pressure from 40 to 155 bar and maintaining said temperature and pressure for 2-60 minutes to obtain a product mix ( 40 ), wherein the lignin feedstock has an average molecular weight below 6500 g/mol and comprises less than 10 wt % of impurities; and
(b) separating ( 120 ) a liquid product mix ( 50 ) from said product mix ( 40 ); and
(c) recirculating at least part of said liquid product mix ( 50 ) as an oil fraction of said solvent ( 20 ).

2. The process according to claim 1 , characterized in that the process further comprises providing lignin feedstock by filtration, nanofiltration, acid precipitation process or membrane fractionation of a lignin source.

3. The process according to claim 1 , characterized in that the process further comprises preparing the feed mixture ( 30 ) by mixing ( 100 ) lignin feedstock ( 10 ) with a solvent ( 20 ) comprising the oil fraction, at least partly produced by the process, at a temperature between 100 and 130° C., under at a pressure from 1 bar to 10 bar, for 5-30 min.

4. The process according to claim 3 , characterized in that preparing the feed mixture ( 30 ) is performed at a temperature from 110° C. and 125° C., at a pressure from 1 bar to 3 bar and/or for 5-15 minutes.

5. The process according to claim 1 , characterized in that the process further comprises preparing the feed mixture ( 30 ) by mixing ( 100 ) lignin ( 10 ) with a solvent ( 20 ) comprising the oil fraction, at least partly produced by the process, at a temperature between 100 and 130° C., under at a pressure from 1 bar to 10 bar, for 5-30 min, followed by filtration and obtaining the feed mixture of lignin fraction(s) and solvent as the filtrate.

6. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) has a molecular weight below 4500 g/mol.

7. The process according to claim 1 , characterized in that an aqueous phase is separated in step (b) before at least part of said liquid product mix ( 50 ) is recirculated as the oil fraction of said solvent ( 20 ).

8. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) comprises 15-98 wt % organics, 0.1-15 wt % ash and/or 1.5-80 wt % water.

9. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) comprises below 40 wt % oxygen daf (dry-ash-free).

10. The process according to claim 1 , characterized in that the process is a continuous, batch or semi-batch process.

11. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) is kraft lignin separated from black liquor.

12. The process according to claim 1 , characterized in that step (b) separation ( 120 ) is followed by fractionation ( 200 ) to obtain one or more oil fraction(s) ( 60 , 61 ) and a heavy fraction ( 62 ) and optionally a bottom residue fraction ( 63 ) and/or a gaseous fraction and optionally recirculating one oil fraction ( 60 ) as the oil fraction of the solvent.

13. The process according to claim 1 , characterized in that the oil fraction is a fraction obtained by fractionation ( 200 ) of the product mix ( 40 ) from the thermal liquefaction step ( 110 ) or of the liquid product mix ( 50 ) obtained after separation ( 120 ).

14. The process according to claim 13 , characterized in that at least part of the oil fraction from said fractionation ( 200 ) is directed to a hydroprocessing step.

15. The process according to claim 1 , characterized in that the solvent further comprises renewable hydrocarbons, oxygen containing hydrocarbons or mixtures thereof.

16. The process according to claim 1 , characterized in that the amount of lignin feedstock is 5 wt % to 35 wt % of the feed mixture.

17. The process according to claim 1 , characterized in that the thermal liquefaction of step (a) ( 110 ) is performed at a temperature from 360° C. to 420° C. at a pressure from 50 to 150 bar and/or for 3-60 minutes.

18. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) has a molecular weight below 3500 g/mol.

19. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) has a molecular weight below 2000 g/mol.

20. The process according to claim 1 , characterized in that the lignin feedstock ( 10 ) has a molecular weight below 1500 g/mol.

21. The process according to claim 1 , characterized in that the amount of lignin feedstock is 8 wt % to 25 wt % of the feed mixture.

22. The process according to claim 1 , characterized in that the amount of lignin feedstock is 10 to 20 wt % of the feed mixture.

23. The process according to claim 1 , wherein the feed mixture does not comprise an alcohol.

Assignees

• Upm Kymmene Corp

Inventors

• Gutierrez Andrea
• Westerhof Roel
• Kersten Sascha
• Heesink Bert
• Jokela Pekka

Classifications

• C10G3/52 Primary

  Hydrogen in a special composition or from a special source · CPC title

• C10G3/60

  Controlling or regulating the processes · CPC title

• C10G49/26

  Controlling or regulating · CPC title

• C10G2300/1014

  of vegetal origin · CPC title

• C10G2300/4006

  Temperature · CPC title