Controlling hydrothermal liquefaction

Patent metadata

Field	Value
Publication number	US-11634645-B2
Application number	US-202117350487-A
Country	US
Kind code	B2
Filing date	Jun 17, 2021
Priority date	Jun 26, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

The present disclosure relates to a method for controlling product slate of hydrothermal liquefaction by adjusting pH of hydrothermal liquefaction product aqueous phase. The pH of the hydrothermal liquefaction product aqueous phase can be adjusted by heating during hydrothermal liquefaction (110) a mix (30) comprising lignocellulosic feedstock (10) together with acids, alkalis and/or buffers (20) added under aqueous conditions. The method typically comprises separating (120) aqueous phase (53) and oil phase (50), and optionally gas (51) and/or char (52), of the obtained hydrothermal liquefaction product (40). Preferably the separated aqueous phase (53) is recirculated to be mixed 100 with lignocellulosic feedstock (10).

First claim

The invention claimed is:

1. A method for controlling product slate of hydrothermal liquefaction characterized in that the method comprises
separating ( 120 ) an aqueous phase ( 53 ) and an oil phase ( 50 ) of a hydrothermal liquefaction product,
adjusting pH of the hydrothermal liquefaction product aqueous phase,
measuring pH of the hydrothermal liquefaction product aqueous phase, and
thermally converting the oil phase ( 50 ).

2. The method according to claim 1 , characterized in that the method comprises adjusting acidity of a mix comprising lignocellulosic feedstock by adding acids, alkalis and/or buffers under aqueous conditions; and subjecting the mix comprising lignocellulosic feedstock to hydrothermal liquefaction.

3. The method according to claim 2 , characterized in that adding acids, alkalis or buffers comprises adding black liquor; black liquor and water; acid salts; alkaline salts; acidic solution; alkaline solution; alkaline aqueous solution; buffers; buffer solution; CO 2 ; recirculated hydrothermal liquefaction product aqueous phase; or a mixture of any of these.

4. The method according to claim 3 , characterized in that the recirculated hydrothermal liquefaction product aqueous phase comprises recycled salts originating from black liquor; and/or from recycled acid salts or alkaline salts; and/or from recycled alkaline salts.

5. The method according to claim 3 , characterized in that the alkaline aqueous solution is black liquor; black liquor and water; recirculated hydrothermal liquefaction product aqueous phase comprising recycled salts originating from black liquor; or a mixture of any of these.

6. The method according to claim 1 , characterized in that a dry biomass to dry black liquor ratio is between 0.5 and 7.

7. The method according to claim 1 , characterized in that the pH of the hydrothermal liquefaction product aqueous phase is at least pH 3.5.

8. The method according to claim 1 , characterized in that controlling product slate comprises controlling formation of oil phase (wt. %), char (wt. %) or a combination thereof versus 100 wt. % hydrothermal liquefaction product.

9. The method according to claim 1 , characterized in that the method comprises a process comprising the following steps
(a) heating during hydrothermal liquefaction ( 110 ) a mix ( 30 ) comprising lignocellulosic feedstock ( 10 ) at a temperature between 290° C. and 450° C., under a pressure from 90 to 350 bar, to obtain the hydrothermal liquefaction product ( 40 ); and
(b) optionally separating gas ( 51 ) and/or char ( 52 ) of the hydrothermal liquefaction product ( 40 ) of step (a).

10. The method according to claim 9 , characterized in that the process further comprises a pretreatment comprising treating the mix ( 30 ) comprising lignocellulosic feedstock ( 10 ) at a temperature between 180° C. and 245° C., under a pressure from 10 to 55 bar, for 10-180 min before heating the mixture according to step (a).

11. The method according to claim 9 , characterized in that the one or more of acid, alkali and buffer ( 20 ) is added to the mix comprising lignocellulosic feedstock before heating the mix according to step (a) or before the pretreatment.

12. The method according to claim 9 , characterized in that the process further comprises recirculating at least part of the hydrothermal liquefaction product aqueous phase to the mix comprising lignocellulosic feedstock ( 10 ); to the pretreatment step; and/or to a hydrothermal treatment step according to step (a).

13. The method according to claim 9 , characterized in that lignocellulosic feedstock ( 10 ) is energy crops, waste or residues of wood-processing, residues of the pulp- and papermaking, and/or residues of timber processes.

14. The method according to according to claim 2 , characterized in that adding acids, alkalis or buffers comprises adding black liquor; alkaline salts chosen from one or more of NaOH, K 2 CO 3 , KOH and Na 2 CO 3 ; recirculated hydrothermal liquefaction product aqueous phase; or a mixture of any of these.

15. The method according to claim 4 , characterized in that the recirculated hydrothermal liquefaction product aqueous phase comprises recycled acid salts or alkaline salts originating from black liquor.

16. The method according to claim 15 , wherein the recycled alkaline salts are chosen from one or more of NaOH, K 2 CO 3 , KOH and Na 2 CO 3 .

17. The method according to claim 1 , characterized in that a dry biomass to dry black liquor ratio is between 0.5 and 6.

18. The method according to claim 1 , characterized in that a dry biomass to dry black liquor ratio is between 0.5 and 2.5.

19. The method according to claim 1 , characterized in that the pH of the hydrothermal liquefaction product aqueous phase is between pH 4 and pH 10.

20. The method according to claim 1 , characterized in that the pH of the hydrothermal liquefaction product aqueous phase is between pH 4.5 and pH 6.

21. The method according to claim 1 , characterized in that the thermal conversion step is a thermal upgrading comprising heating the oil phase of step (b) and solvent at a temperature between 360° C. and 450° C. under a pressure from 50 to 120 bar.

22. The method according to claim 21 , characterized in that the solvent is crude tall oil, acid oil, vegetable oil, renewable hydrocarbons, or mixtures thereof.

23. The method according to claim 9 , characterized in that the lignocellulosic feedstock is seeds, residues of wood processing, or a combination thereof.

24. The method according to claim 9 , characterized in that the lignocellulosic feedstock is seed crop, slash, urban wood waste, lumber waste, wood chips, wood branches, bark, wood sawdust, straw, firewood, plywood residual, or a combination thereof.

25. The method according to claim 9 , characterized in that the lignocellulosic feedstock is Brassica carinata seed, wood chips, bark, sawdust, or a combination thereof.

Assignees

• Upm Kymmene Corp

Inventors

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

Classifications

• C10G2300/4006

  Temperature · CPC title

• Y02P30/20

  using bio-feedstock · CPC title

• C10G1/00 Primary

  Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal (mechanical winning of oil from oil-shales, oil-sand, or the like B03B) · CPC title

• C10G1/06

  by destructive hydrogenation · CPC title

• C10G2300/1014

  of vegetal origin · CPC title