Process for the conversion of lignocellulosic solutions containing a high proportion of dry material

• US 8,623,175 B2
• Filed: 10/29/2008
• Issued: 01/07/2014
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: Rolland, Matthieu
• Primary Examiner(s): CALANDRA, ANTHONY J
• Application Number:
  US12/809,483
• Publication Number:
  US 20110008850A1
• Time in Patent Office: 1,896 Days
• Field of Search: 162/41, 162/42
• US Class Current: 162/42
• CPC Class Codes: B30B 9/06 co-operating with permeable casings or strainers
• CPC Class Codes: B30B 9/12 using pressing worms or screws co-operating with a permeable casing
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 7/02 containing a hydroxy group
• CPC Class Codes: D21C 3/22 Other features of pulping processes
• CPC Class Codes: D21C 3/224 Use of means other than pressure and temperature
• CPC Class Codes: D21C 9/18 De-watering de-watering in general F26B; Elimination of cooking or pulp-treating liquors from the pulpD21C9/002, D21C9/02 take precedence; paper-making machines D21F; strainers in digesters D21C7/00; presses in general B30B

Abstract

The invention describes a process for the conversion of aqueous solutions of lignocellulosic solids comprising a solids content of between 1 and 20% of dry material, said process comprising a step a) for compression of said solution so as to separate the liquid phase present in and between the solids from the compressed solid phase and a step b) for extraction of at least the liquid phase, said liquid phase then being homogenised by heat and/or chemical treatments and reinjected on to the compressed solid phase.

Claims

1. A process for the conversion of an aqueous suspension of lignocellulosic solids comprising a solids content of between 1 and 20% of dry material, said process comprising:

mechanical compression of said aqueous suspension so as to separate a liquid phase present in and between the solids from a compressed solid phase; and

extraction of at least said liquid phase, said liquid phase then being homogenized by heat and/or chemical treatments and directly re-mixed with said solid phase, said mechanical compression comprising subjecting the aqueous suspension to a perforated compression piston operated with a vertical or rotary motion.

2. The process according to claim 1, wherein said compression is carried out in accordance with a vertical compression axis.

4. The process according to claim 1, wherein said compression is performed with agitation, and wherein said agitation is effected by means of an agitator axis having a drive shaft internal and coaxial with said compression shaft of said perforated compression piston.

5. The process according to claim 4, wherein said compression piston is a rotary compression piston equipped with protuberances projecting over at least a part of the height of the aqueous suspension of lignocellulosic solids.

6. The process according to claim 5, wherein the shaft of said rotary compression piston is equipped with blades above the perforated grill in the liquid phase.

7. The process according to claim 1, wherein said compression is conducted in a reactor and an enzymatic hydrolysis reaction is performed in said reactor.

8. The process according to claim 7, wherein an alcoholic fermentation reaction also takes place simultaneously with said enzymatic hydrolysis reaction in said reactor.

9. The process according to claim 8, wherein said liquid phase passes into a process for conversion of the cellobiose into glucose wherein additional enzymatic hydrolysis is performed external to said reactor.

10. The process according to claim 7, wherein said liquid phase passes into a separate fermentation process, and the effluent from said fermentation process is reinjected at the head of said reactor.

11. The process according to claim 1, wherein said aqueous suspension has a solids content of between 1 and 15% of dry material.

12. The process according to claim 1, wherein said aqueous suspension has a solids content of between 8 and 15% of dry material.

18. The process according to claim 1, wherein the compressed solid phase is also extracted in said extraction and reinjected at the head of the reactor.

20. The process according to claim 1, wherein the compressed solid phase is reinjected and dispersed at the head of the reactor.

22. The process according to claim 20, wherein the compressed solid phase is reinjected by means of a static or rotary dispersion cone, with a half-angle at the top of between 30 and 60°

C. and of a diameter between ⅓ and

¼

of the diameter of the reactor.

24. The process according to claim 4, wherein the compressed solid phase is reinjected by means of a rotary dispersion plate of a diameter of between ⅓

and ¼

of the diameter of the reactor, said plate being driven by the drive shaft of the agitator.

3. A process for the conversion of an aqueous suspension of lignocellulosic solids comprising a solids content of between 1 and 20% of dry material, said processing comprising:

compression of said aqueous suspension so as to separate a liquid phase present in and between the solids from a compressed solid phase; and

extraction of at least said liquid phase, said liquid phase then being homogenized by heat and/or chemical treatments and re-mixed with said solid phase, wherein said compression is carried out in a reactor comprising a perforated compression piston, said perforated compression piston comprising three distinct components;

a perforated grill,

a grill support, and

a compression shaft which is perpendicular to said grill.

13. The process according to claim 3, wherein the volume of said reactor is pumped at least 3 times before the piston is raised.

14. The process according to claim 3, wherein said compression is performed with agitation.

15. The process according to claim 14, wherein said agitation is effected by means of an agitator axis having a drive shaft internal and coaxial with said compression shaft of said perforated compression piston.

16. The process according to claim 3, wherein said compression piston is a rotary compression piston equipped with protuberances projecting over at least a part of the height of the aqueous suspension of lignocellulosic solids.

17. The process according to claim 16, wherein the shaft of said rotary compression piston is equipped with blades above the perforated grill in the liquid phase.

19. The process according to claim 3, wherein the compressed solid phase is also extracted in said extraction and reinjected at the head of the reactor.

21. The process according to claim 3, wherein the compressed solid phase is reinjected and dispersed at the head of the reactor.

23. The process according to claim 21, wherein the compressed solid phase is reinjected by means of a static or rotary dispersion cone, with a half-angle at the top of between 30 and 60°

C. and of a diameter between ⅓ and

¼

of the diameter of the reactor.