High temperature bio-char carbonization and micron grinding and classification for inclusion into master batch polymerization

• US 10,619,102 B2
• Filed: 04/26/2019
• Issued: 04/14/2020
• Est. Priority Date: 04/27/2018
• Status: Active Grant

• Current Assignee: Thomas Jefferson University (Main Line Health System)
• Original Assignee: Thomas Jefferson University (Main Line Health System)
• Inventors: Sunderland, Mark
• Primary Examiner(s): Pilcher, Jonathan Luke
• Application Number:
  US16/395,515
• Publication Number:
  US 20190330532A1
• Time in Patent Office: 354 Days
• CPC Class Codes: B02C 17/186 Adding fluid, other than for crushing by fluid energy
• CPC Class Codes: B02C 23/12 with return of oversize material to crushing or disintegrating zone
• CPC Class Codes: C08J 2300/12 Polymers characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
• CPC Class Codes: C08J 3/22 using masterbatch techniques
• CPC Class Codes: C08J 3/226 using a polymer as a carrier
• CPC Class Codes: C08K 2201/001 Conductive additives
• CPC Class Codes: C08K 2201/005 Additives being defined by their particle size in general
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C10B 53/02 of cellulose-containing material production of pyroligneous acid C10C5/00
• CPC Class Codes: C10B 57/16 Features of high-temperature carbonising processes
• CPC Class Codes: D01C 1/00 Treatment of vegetable material
• CPC Class Codes: D01F 9/16 from products of vegetable origin or derivatives thereof, e.g. from cellulose acetate D01F9/18 takes precedence
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

A thermal process for carbonizing hemp and reducing particle size, mechanically, by grinding or milling said carbonized hemp materials to generate a precise particle size hemp char and combining the hemp char particles with a polymer into a master batch.

Claims

1. A process for creating a mixture of micron-sized charred hemp comprising:

rough cutting a portion of hemp stalk, said portion of hemp stalk comprising fiber and hurd materials;

charring the portion of hemp stalk at a temperature of greater than 1100°

Celsius to create a char material;

milling the char material to create a milled char;

classifying the milled char with a classification system of less than 10 micron size to create a fraction of hemp char particles;

collecting a desired fraction from the classification system of hemp char particles of less than 10 microns in size.

2. The process of claim 1, comprising a first step of drying the hemp stalk before the rough cutting step.

3. The process of claim 1, wherein the temperature of greater than 1100°

C. is held for at least one hour, and wherein the charring process is performed by addition of a non-oxygen gas to a heating chamber.

4. The process of claim 1, wherein the milling is performed in a high energy ball mill.

5. The process of claim 1, wherein the classification system includes a classification of 2 microns or less.

6. The process of claim 1, where the desired fraction from the classification system are admixed with a polymer.

7. The process of claim 6, wherein a material comprising the desired fraction and the polymer transmits an electrical charge with a resistance of less than 100Ω

.

8. The process of claim 1, wherein the desired fraction from the classification system comprises a 95% specific classification size of less than 2 microns and a 95% bell curve of 1.5 microns.

9. A process for creating a masterbatch comprising a plurality of hemp char particles and a polymer comprising:

carbonizing a portion of a hemp material in a furnace, said portion of hemp material comprising hemp fiber and hurd, said furnace being flushed with nitrogen and then heated to greater than 1100°

C.;

wherein the temperature greater than 1100°

C. is held for at least 60 minutes;

nitrogen flow is maintained over the at least 60 minutes to maintain a low oxygen environment to create a char;

removing the char from the furnace and allowing it to cool;

milling the char by a milling process for a period sufficient to reduce the char into a plurality of particles having average particle size of less than 2 microns to create char particles of less than 2 microns;

combining the char particles having an average particle size of less than 2 microns with the polymer, wherein the ratio of char particles to polymer is between 10;

90 and 50;

50; and

mixing the polymer and the char particles to form the masterbatch.

10. The method of claim 9, wherein at least 90% of char particles are less than 2 microns in size.

11. The method of claim 9, wherein the average particle size of the char particles is between 1 and 2 microns, and wherein at least 95% of the char particles are less than 2 microns in size.

12. The method of claim 9, wherein the milling process is carried out using a ball mill.

13. The method of claim 9, wherein the milling process is a wet milling process.

14. The method of claim 13, wherein the wet milling process comprises use of a non-aqueous solvent.

15. The method of claim 9, wherein the char particles having an average size of less than 2 microns are classified to remove particles of more than 2 microns in size.

16. A process of forming charred hemp particles of less than 2 micron in size, comprising:

drying cut hemp stalk on a field for a period of less than 7 days, said hemp stalk comprising fiber and hurd;

pyrolyzing the dried hemp stalk at 1100°

-1500°

Celsius to create a char;

adding the char to a grinding vessel and grinding the char for a period of 1 to 16 hours;

screening the ground char with a 2 micron screen to create a screened char of less than 2 microns; and

capturing the screened char of less than 2 microns.

17. The process of claim 16, wherein the grinding vessel is a steel vessel with steel grinding balls.

18. The process of claim 16, wherein the grinding is dry grinding.

19. The process of claim 16, wherein the grinding is wet grinding.

20. The process of claim 19, wherein the wet grinding is performed for a first duration of between 1 and 16 hours and followed by a step of drying to create an agglomerated ground char and re-grinding the agglomerated ground char in a dry grinding process.

21. The process of claim 18 further comprising separating the material resulting from the 2-micron screen to particles smaller than 2 micron and particles larger than 2 microns and re-grinding the particles having a particle size greater than 2 microns.