PROCESS FOR OBTAINING CELLULOSE

• US 20160168790A1
• Filed: 07/25/2014
• Published: 06/16/2016
• Est. Priority Date: 07/25/2013
• Status: Active Grant

• Current Assignee: Rainer Fulling
• Original Assignee: Rainer Fulling
• Inventors: Flling, Rainer, Schlabach, Heiko
• Granted Patent: US 11,512,426 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C08B 1/00 Preparatory treatment of cellulose for making derivatives thereof , e.g. pre-treatment, pre-soaking, activation
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: D21C 1/00 Pretreatment of the finely-divided materials before digesting of waste paper D21C5/02
• CPC Class Codes: D21C 1/10 Physical methods for facilitating impregnation
• CPC Class Codes: D21C 11/00 Regeneration of pulp liquors or effluent waste waters
• CPC Class Codes: D21C 11/04 of alkali lye
• CPC Class Codes: D21C 3/02 with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
• CPC Class Codes: D21C 3/224 Use of means other than pressure and temperature
• CPC Class Codes: D21C 5/02 Working-up waste paper mechanical part D21B1/08, D21B1/32
• CPC Class Codes: D21C 7/00 Digesters
• CPC Class Codes: D21C 7/14 Means for circulating the lye
• CPC Class Codes: D21C 9/08 Removal of fats, resins, pitch or waxes; Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching fats, waxes C11B; natural resins C09F1/00; hemicellulose C08B37/14; purification by mechanical means D21D5/00
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02W 30/64 Paper recycling

Abstract

The present invention relates to a process for obtaining cellulose or a mixture containing at least cellulose and at least lignocellulose from at least one substrate that is at least to some extent amenable to fermentation comprising at least the steps of (1) to (3) and optionally (4), namely conversion of the substrate via addition of at least one inorganic base into an aqueous mixture with pH≧8.5 (step 1), ultrasound treatment of the aqueous mixture obtained after step (1) (step 2), separation of the aqueous mixture obtained after step (2) into a liquid aqueous phase and a disperse mixture containing, cellulose or a mixture containing at least cellulose and at least lignocellulose (step 3) and optionally purification of the disperse mixture obtained after step (3) containing cellulose or of the mixture containing at least cellulose and at least lignocellulose (step 4), where step (1) and step (2) of the process respectively are carried out at a temperature <100° C. and where the ultrasound treatment in step (2) takes place in one or more treatment phases, where tile duration of a treatment phase is in the range from 0.2 to 60 seconds and each treatment phase is carried out with a sonotrode frequency in the range from 14 to 22 kHz.

Claims

1. A process for obtaining cellulose or a mixture containing at least cellulose and at least lignocellulose from at least one substrate that is at least to some extent amenable to fermentation comprising at least the steps (1) to (3) and optionally (4), namely

(1) conversion of the substrate via addition of at least one inorganic base into an aqueous mixture having a p≧

8.5,

(2) ultrasound treatment of the aqueous mixture obtained after step (1),

(3) separation of the aqueous mixture obtained after step (2) into a liquid aqueous phase and a disperse mixture containing cellulose or a mixture containing at least cellulose and at least lignocellulose and

(4) optionally purification of the disperse mixture obtained after step (3) containing cellulose or a mixture containing at least cellulose and at least lignocellulose,

wherein step (1) and step (2) of the process are both carried out at a temperature of <

100°

C. and

wherein the ultrasound treatment in step (2) is effected in one or more treatment phases, where the duration of a treatment phase is in the range from 0.2 to 60 seconds and each treatment phase is carried out at a sonotrode frequency in a range from 14 to 22 kHz.

2. The process as claimed in claim 1, wherein the duration of a treatment phase in step (2) is in the range of 0.5 to 30 seconds.

3. The process as claimed in claim 1, wherein the treatment phase in step (2) is carried out at a sonotrode frequency in a range from 16 to 20 kHz.

4. The process as claimed in claim 1, wherein a power of at least 2 kW is supplied to the mixture to be treated in the treatment phase in step (2).

5. The process as claimed in claim 4, wherein the power corresponds to a power input in the range of 1 to 10 W/cm² of the entire circumference of the sonotrodes.

6. The process as claimed in claim 1, wherein the ultrasound treatment in step (2) of the process is carried out by means of at least one ultrasound unit, wherein each ultrasound unit comprises at least one ultrasound transducer and at least one ultrasound oscillator.

7. The process as claimed in claim 1, wherein step (1) and step (2) of the process are both carried out at a temperature in the range of 50°

C. to 70°

C.

8. The process as claimed in claim 1, wherein a pH in the range of 9 to 13 is set in step (1).

9. The process as claimed in claim 1, wherein the at least one inorganic base used in step (1) is a base selected from the group consisting of NaOH, KOH, Na₂CO₃, K₂CO₃, CaO, Ca(OH)₂ and MgO and also mixtures thereof.

10. The process as claimed in claim 1, wherein an aqueous solution or dispersion of an inorganic base is used in step (1) comprising a proportion of inorganic base in the range of 30 to 80% by weight, based on the total weight of the aqueous solution or dispersion containing the at least one inorganic base.

11. The process as claimed in claim 10, wherein the aqueous solution or dispersion of the inorganic base in step (1) is used in an amount in the range of 1 to 10 mL per L of the at least one substrate that is amenable to fermentation.

12. The process as claimed in claim 1, wherein the separation in step (3) is in the form of a mechanical separation.

13. The process as claimed in claim 1, wherein the separation in step (3) is effected by means of sieve filtration, centrifugation or a combined sieve filtration centrifugation.

14. The process as claimed in claim 1, wherein the purification in step (4) is effected by washing, decanting, sieving and/or sieve filtration by addition of water.

15. The process as claimed in claim 1, wherein that raw sludge originating from waste water is used as the at least one substrate that is at least to some extent amenable to fermentation.

16. The process as claimed in claim 2, wherein the treatment phase in step (2) is carried out at a sonotrode frequency in a range from 16 to 20 kHz.

17. The process as claimed in claim 3, wherein a power of at least 2 kW is supplied to the mixture to be treated in the treatment phase in step (2).

18. The process as claimed in claim 17 wherein the power corresponds to a power input in the range of 1 to 10 W/cm² of the entire circumference of the sonotrodes.