Processes for recovering rubber from aged briquettes

Patent metadata

Field	Value
Publication number	US-10316110-B2
Application number	US-201715498983-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Mar 6, 2012
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

Provided herein are organic solvent-based processes for the removal of rubber from aged briquettes made from compressed plant matter (briquettes) of non- Hevea plants.

First claim

What is claimed is:

1. A method of recovering rubber from rubber-containing briquettes comprising:
a. utilizing aged briquettes comprising at least one antioxidant and chopped plant matter that contains bagasse, rubber, resin and less than 5 weight % leaves of a non- Hevea plant, wherein the briquettes have been aged for about 21-200 days after formation;
b. mixing the briquettes with (i) at least one non-polar organic solvent and (ii) at least one polar organic solvent to produce a slurry where the total amount of (i) and (ii) is 50-90% by weight of the slurry, the briquettes comprise 10-50% by weight of the slurry, and the slurry contains 0.5-10 weight % water;
c. removing a majority of the bagasse from the slurry to produce a miscella and a first bagasse portion;
d. optionally adding additional polar organic solvent, non-polar solvent or a combination thereof to the miscella to form a reduced viscosity miscella, wherein any additional polar organic solvent and non-polar organic solvent that is added is the same or different than those utilized in (a) and the amount of any additional polar organic solvent added is less than the amount that causes the rubber contained with the reduced viscosity miscella to coagulate;
e. removing 80-95 weight % bagasse (based upon the total weight of bagasse present in the reduced viscosity miscella) from the miscella produced in (c) or (d) thereby forming a purified miscella and a second bagasse fraction, wherein a majority of the bagasse that is removed has a particle size of less than 105 microns;
f. optionally treating the purified miscella to remove additional bagasse thereby producing a clarified rubber solution that contains 0.01-1% by weight bagasse (based on the total weight of bagasse present in the slurry) thereby producing a clarified rubber solution;
g. increasing the relative amount of polar solvent as compared to non-polar solvent within the purified miscella or clarified rubber solution so as to coagulate the rubber; and
h. producing solid purified rubber from the coagulated rubber where when said solid purified rubber contains 0.8% volatile matter it also contains 0.05-0.5 weight % dirt, 0.2-1.5 weight % ash and 0.1-4 weight % resin,

wherein at least (b)-(f) are conducted at a temperature or temperatures of 10-80° C. and a pressure of 35 to 1000 kPa.

2. The method of claim 1 , wherein the briquettes have been aged for 90-200 days after formation and prior to (b) and the rubber within the briquettes has a molecular weight of at 900,000-1,300,000.

3. The method of claim 1 , wherein the briquettes have been aged for 21-24 days after formation and prior to (b) and the rubber within the briquettes has a molecular weight of 1,200,000-1,500,000.

4. The method of claim 1 , wherein the briquettes contain 80-100% by weight bark, less than 20% by weight woody material and less than 1% by weight leaves.

5. The method of any of claim 1 , wherein the briquettes contain 5 weight % or less woody material.

6. A method of recovering rubber from rubber-containing briquettes comprising:
a. utilizing aged briquettes comprising at least one antioxidant and chopped plant matter that contains bagasse, rubber, resin and less than 5 weight % leaves of guayule plant, wherein the briquettes have been aged for about 21-200 days after formation;
b. mixing the briquettes with (i) at least one non-polar organic solvent and (ii) at least one polar organic solvent to produce a slurry where the total amount of (i) and (ii) is 50-90% by weight of the slurry, the briquettes comprise 10-50% by weight of the slurry, and the slurry contains 0.5-10 weight % water;
c. removing a majority of the bagasse from the slurry to produce a miscella and a first bagasse portion;
d. optionally adding additional polar organic solvent, non-polar solvent or a combination thereof to the miscella to form a reduced viscosity miscella, wherein any additional polar organic solvent and non-polar organic solvent that is added is the same or different than those utilized in (a) and the amount of any additional polar organic solvent added is less than the amount that causes the rubber contained with the reduced viscosity miscella to coagulate;
e. removing 80-95 weight % bagasse (based upon the total weight of bagasse present in the reduced viscosity miscella) from the miscella produced in (c) or (d) thereby forming a purified miscella and a second bagasse fraction, wherein a majority of the bagasse that is removed has a particle size of less than 105 microns;
f. optionally treating the purified miscella to remove additional bagasse thereby producing a clarified rubber solution that contains 0.01-1% by weight bagasse (based on the total weight of bagasse present in the slurry) thereby producing a clarified rubber solution;
g. increasing the relative amount of polar solvent as compared to non-polar solvent within the purified miscella or clarified rubber solution so as to coagulate the rubber; and
h. producing solid purified rubber from the coagulated rubber where when said solid purified rubber contains 0.8% volatile matter it also contains 0.05-0.5 weight % dirt, 0.2-1.5 weight % ash and 0.1-4 weight % resin,

wherein at least (b)-(f) are conducted at a temperature or temperatures of 10-80° C. and a pressure of 35 to 1000 kPa.

7. The method of claim 1 , wherein the chopped plant matter has an average size of 0.062-0.5″ prior to being compressed into the briquette.

8. The method of claim 1 , wherein the chopped plant matter of the briquettes is guayule plant matter.

9. The method of claim 1 , wherein at least one of (b) or (d) comprises the use of a centrifuge.

10. The method of claim 1 , wherein (b) comprises the use of a counter-current extractor.

11. The method of claim 1 , wherein:
the at least one polar organic solvent and additional polar organic solvent are selected from the group consisting of alcohols having 1 to 8 carbon atoms; ethers and esters having from 2 to 8 carbon atoms; cyclic ethers having from 4 to 8 carbon atoms; ketones having from 3 to 8 carbon atoms; and combinations thereof; and
the at least one non-polar organic solvent is selected from the group consisting of alkanes having from 4 to 9 carbon atoms; cycloalkanes and alkyl cycloalkanes having from 5 to 10 carbon atoms; aromatics and alkyl substituted aromatics having from 6 to 12 carbon atoms; and combinations thereof.

12. The method of claim 1 , wherein additional organic solvent is added in (d) in an amount sufficient to produce a reduced viscosity miscella with a viscosity of 10-300 centipoise prior to removing of the bagasse in (e).

13. The method of claim 1 , wherein the slurry in step (a) contains 25-50% by weight of material from the briquettes and 50-75% by weight non-polar organic solvent and polar organic solvent.

14. The method of claim 1 , wherein the (i) at least one non-polar organic solvent of (b); and the (ii) at least one polar organic solvent of (b) are present in relative weight amounts of 50-90% and 10-50%, respectively.

15. The method of claim 6 , wherein the chopped plant matter is subjected to roll/flake milling prior to being compacted into the briquettes.

16. The method of claim 6 , wherein at least one of (b) or (d) comprises the use of a centrifuge.

17. The method of claim 6 , wherein:
the at least one polar organic solvent and additional polar organic solvent are selected from the group consisting of alcohols having 1 to 8 carbon atoms; ethers and esters having from 2 to 8 carbon atoms; cyclic ethers having from 4 to 8 carbon atoms; ketones having from 3 to 8 carb

Assignees

• Bridgestone Corp

Inventors

• Huang Yingyi
• Smale Mark W
• White Robert
• Mouri Hiroshi
• Cole William M

Classifications

• C08C2/02 Primary

  Purification · CPC title

• C08C1/04 Primary

  Purifying; Deproteinising · CPC title

• C08G83/00

  Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00 · CPC title

• C08C4/00

  Treatment of rubber before vulcanisation, not provided for in groups C08C1/00 - C08C3/02 · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title