Integrated process for processing and utilising the guayule plant

Patent metadata

Field	Value
Publication number	US-9969818-B2
Application number	US-201515515299-A
Country	US
Kind code	B2
Filing date	Oct 21, 2015
Priority date	Oct 22, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention relates to an integrated process for processing and utilizing every part of the guayule plant ( Parthenium argnetatum ) which comprises the following steps in sequence: separating the stem and branches from the leaves of said plant with a mechanical treatment; treating the leaves to produce waxes and essential oils, and a fraction containing cellulose, hemicellulose (carbohydrates) and, to a minor extent, salts, organic compounds and lignin; extracting from the stem and branches a liquid phase, so forming a first solid woody residue, indicated with bagasse in the present text; treating said first solid woody residue to prepare sugars, resin, rubber and lignin.

First claim

The invention claimed is:

1. A process for processing and utilising every part of a guayule plant ( Parthenium argentatum ) comprising the following steps in sequence:
separating the stem and branches from the leaves of said guayule plant with a mechanical treatment;
treating the leaves to produce waxes and essential oils, and to form a solid fraction containing cellulose, hemicellulose, salts, lignin and other organic compounds;
extracting from the stem and branches a liquid phase and thereby forming a first solid woody residue;
treating said first solid woody residue to form sugars, resin, rubber and lignin.

2. The process according to claim 1 , wherein the stem and branches are treated by extraction conducted with basic water to form an aqueous emulsion comprising the first solid woody residue.

3. The process according to claim 2 , further comprising extracting a concentrated latex from said aqueous emulsion and coagulating and separating a natural rubber from the concentrated latex.

4. The process according to claim 1 , wherein the stem and branches are treated by extraction with a nonpolar organic solvent to form an organic solution and the first solid woody residue.

5. The process according to claim 4 , further including extracting a natural rubber from said organic solution, and dispersing the natural rubber subsequently in water to form latex.

6. The process according to claim 1 , wherein the first solid woody residue is treated according to the following steps in sequence:
extracting resin and rubber from said first solid woody residue and forming a fifth solid woody residue containing lignin, hemicellulose and cellulose;
hydrolysing said fifth solid woody residue to form sugars having 5 carbon atoms and a sixth solid woody residue containing lignin and cellulose;
hydrolysing said sixth solid residue to convert the cellulose into sugars having 6 carbon atoms, and forming a final solid residue containing lignin and an amount of residual cellulose of less than 20%.

7. The process according to claim 6 , wherein the first solid woody residue is treated by extraction with a nonpolar organic solvent.

8. The process according to claim 6 , wherein hydrolysing the fifth solid woody residue is conducted by acid hydrolysis.

9. The process according to claim 8 , wherein hydrolysing is carried out with a phosphonic acid of general formula RPO(OH) 2 (I), in which R is a linear or branched alkyl group, or an aromatic group, or a group containing a heteroatom.

10. The process according to claim 9 , in which R is an alkyl group containing from 1 to 6 carbon atoms, or R is selected from the compounds of formula R′—C 6 H 5 or R′—C 10 H 8 where R′ is a linear or branched alkyl group having from 1 to 3 carbon atoms, or R is a group containing a heteroatom selected from those containing oxygen (O) or containing nitrogen (N) or containing phosphorus (P).

11. The process according to claim 9 , wherein R is methyl, ethyl, or CH 3 OH—PO(OH) 2 .

12. The process according to claim 8 wherein the pH during acid hydrolysis is between 0.6 and 1.6.

13. The process according to claim 6 , wherein hydrolysing the sixth solid residue is conducted by enzymatic hydrolysis, chemical hydrolysis, or thermochemical hydrolysis.

14. The process according to claim 1 , in which the first solid residue is treated according to the following steps in sequence:
treating the first solid woody residue to form sugars having 5 carbon atoms and a second solid residue,
treating said second solid residue to form sugars having 6 carbon atoms and a third solid residue,
extracting resin and rubber from said third solid residue to form a fourth woody residue mainly comprising lignin.

15. The process according to claim 14 , further comprising treating the third solid woody residue by solvent extraction with an organic nonpolar solvent to separate the resin and rubber and to form a fifth solid woody residue comprising lignin, hemicellulose and cellulose.

16. The process according to claim 14 , wherein treating the first solid woody residue is conducted by acid hydrolysis to convert the hemicellulose into sugars having 5 carbon atoms and thereby forming the second solid woody residue comprising lignin and cellulose.

17. The process according to claim 16 , wherein acid hydrolysis is carried out with a phosphonic acid of general formula R—PO(OH) 2 (I), in which R is a linear or branched alkyl group, or an aromatic group, or a group containing a heteroatom.

18. The process according to claim 17 , in which R is an alkyl group containing from 1 to 6 carbon atoms, or R is selected from the compounds of formula R′—C 6 H 5 or R′—C 10 H 8 where R′ is a linear or branched alkyl group having from 1 to 3 carbon atoms, or R is a group containing a heteroatom selected from oxygen (O), nitrogen (N) or phosphorus (P).

19. The process according to claim 18 , in which R is methyl, ethyl or CH 3 OH—PO(OH) 2 .

20. The process according to claim 16 , wherein the pH during acid hydrolysis is between 0.6 and 1.6.

21. The process according to claim 16 , wherein said second woody residue is treated by enzymatic hydrolysis, chemical hydrolysis, or thermochemical hydrolysis.

22. The process according to claim 1 , further comprising:
subjecting the solid fraction containing cellulose, hemicellulose, lignin, salts and other organic compounds
to acid hydrolysis to convert the hemicellulose into monomeric sugars having 5 carbon atoms, and to form an intermediate product containing cellulose,
subjecting said intermediate product to further hydrolysis to convert the cellulose into sugars having 6 carbon atoms.

23. The process according to claim 22 , wherein acid hydrolysis is carried out with an organic acid selected from the phosphonic acids of general formula R—PO(OH) 2 (I) or from alkylsulfonic acids of general formula R 1 —SO 3 H (II), in which R is selected from a linear or branched alkyl group, an aromatic group, or a group containing a heteroatom, and R 1 is selected from a linear or branched alkyl group having 1 to 6 carbon atoms.

24. The process according to claim 23 , wherein R is an alkyl group containing from 1 to 6 carbon atoms, or R is selected from the compounds of formula R′—C 6 H 5 or R′—C 10 H 8 where R′ is a linear or branched alkyl group having from 1 to 3 carbon atoms, or R is a group containing a heteroatom selected from oxygen (O), nitrogen (N) or phosphorus (P).

25. The process according to claim 24 , wherein R is selected from methyl, ethyl or CH 3 OH—PO(OH) 2 .

26. The process according to claim 23 , wherein R 1 is methyl.

27. The process according to claim 22 , further comprising producing with the C5 sugars and C6 sugars chemicals, microbial oils or biofuels by fermentation.

28. The process according to claim 27 , wherein the produced chemicals are butandiols or bio-butadiene.

29. The process according to claim 22 , wherein the pH during acid hydrolysis is between 0.6 and 1.6.

30. The process according to claim 22 , further comprising separating the waxes and essential oils by a method selected from solvent extraction or steam extraction or extraction with supercritical CO 2 .

31. The process according to claim 22 , wherein the further hydrolysis of the intermediate product is conducted by a method selected from enzymatic hydrolysis, c

Assignees

• Versalis Spa

Inventors

• Battistel Ezio
• Ramello Stefano
• Querci Cecilia

Classifications

• C08C1/00 Primary

  Treatment of rubber latex · CPC title

• C08C2/02

  Purification · CPC title

• C08C1/04

  Purifying; Deproteinising · CPC title

• C08C1/02

  Chemical or physical treatment of rubber latex before or during concentration · CPC title

• C08C2/06 Primary

  Winning of rubber from solutions · CPC title