Screw compression process for the conversion of lignocellulosic suspensions containing a high proportion of dry material

• US 8,940,131 B2
• Filed: 10/30/2013
• Issued: 01/27/2015
• 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:
  US14/067,448
• Publication Number:
  US 20140106412A1
• Time in Patent Office: 454 Days
• Field of Search: 162/42, 162/45, 435/105, 435/155
• 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 suspensions 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 suspension 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 homogenized by heat and/or chemical treatments and reinjected on to the compressed solid phase.

Claims

1. A process for the conversion of aqueous suspensions 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 suspensions so as to separate 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, said compression a comprising being conducted by a screw compression in a reactor comprising a screw, and wherein the compressed solid phase is also extracted in the extraction step b) and reinjected at the head of the reactor.

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 compressed solid phase is reinjected and dispersed at the head of the reactor.

4. A process according to claim 3 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.

5. A process according to claim 3 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.

6. A process according to claim 1, said compression comprising carrying out an enzymatic hydrolysis reaction.

7. A process according to claim 6 wherein an alcoholic fermentation reaction also takes place simultaneously with the enzymatic hydrolysis reaction.

8. A process according to claim 7 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.

9. A process according to claim 6 in which the liquid phase passes into a separate fermentation process, and effluent from the fermentation process then being reinjected at the head of the reactor.

10. A process according to claim 7 in which the liquid phase passes into a separate fermentation process, and effluent from the fermentation process then being reinjected at the head of the reactor.