PROCESS FOR THE CONVERSION OF LIGNOCELLULOSIC SOLUTIONS CONTAINING A HIGH PROPORTION OF DRY MATERIAL

• US 20110008850A1
• Filed: 10/29/2008
• Published: 01/13/2011
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: Rolland, Matthieu
• Granted Patent: US 8,623,175 B2
• Time in Patent Office: Days
• US Class Current: 435/105
• 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 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 re-mixed with the solid phase.

2. A process according to claim 1 wherein the compression step a) is carried out in accordance with a vertical compression axis.

3. A process according to claim 1 wherein the compression step a) is carried out in a reactor comprising a perforated compression piston, said compression piston comprising three distinct components:

a perforated grill,

a grill support, and

a compression shaft which is perpendicular to said grill.

4. A process according to claim 1 wherein the compression step a) is performed with agitation.

5. A process according to claim 4 wherein agitation is effected by means of an agitator axis whose drive shaft is internal and coaxial with the compression shaft of the piston.

6. A process according to claim 4 wherein said compression piston is a rotary compression piston equipped with protuberances projecting over a part at least of the height of the aqueous solution of lignocellulosic solids.

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

8. A process according to claim 1 wherein the compression step a) is carried out in a screw.

9. A process according to claim 8 wherein the compression step a) is carried out in a reactor comprising a screw.

10. A process according to claim 9 wherein the compressed solid phase is also extracted in the extraction step b) and reinjected at the head of the reactor.

11. A process according to claim 10 wherein the compressed solid phase is reinjected and dispersed at the head of the reactor.

12. A process according to claim 11 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°

and of a diameter between ⅓ and

¼

of the diameter of the reactor.

13. A process according to claim 11 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.

14. A process according to claim 1 carrying out the enzymatic hydrolysis reaction.

15. A process according to claim 14 wherein an alcoholic fermentation reaction also takes place simultaneously with the enzymatic hydrolysis reaction.

16. A process according to claim 15 wherein the liquid phase passes into a process for conversion of the cellobiose into glucose so as to effect additional enzymatic hydrolysis at the outside of said reactor.

17. A process according to claim 14 in which the liquid phase passes into a separate fermentation process, the effluent from the fermentation operation then being reinjected at the head of the reactor.