Method for producing microcrystalline cellulose from tobacco and related tobacco product
Methods for producing dissolving grade pulp and microcrystalline cellulose from tobacco are provided. The methods include chemical pulping a tobacco input to form a tobacco pulp. Chemical pulping the tobacco input includes combining the tobacco input with a strong base defining a weight from about 5% to about 50% of the tobacco input, and heating the tobacco input and the strong base with an H-factor from about 500 to about 3,300. Further, the methods include bleaching the tobacco pulp to produce a dissolving grade pulp. Bleaching the tobacco pulp may include chlorination of the tobacco pulp with a chlorine dioxide solution, and caustic extraction of the tobacco pulp with a second strong base. A related tobacco-derived microcrystalline cellulose product is also provided, which can be used as a binder, a filler, and/or a texturizer in a tobacco product, such as a smokeless tobacco product.
1. A method for processing tobacco, the method comprising:
i) chemical pulping a tobacco input to form a tobacco pulp, wherein chemical pulping the tobacco input comprises:
combining the tobacco input with a strong base having a weight from about 5% to about 50% of the weight of the tobacco input, and
heating the tobacco input and the strong base with an H-factor from about 500 to about 3,300; and
ii) bleaching the tobacco pulp to produce a dissolving grade pulp.
2. The method of claim 1 , wherein the tobacco input comprises tobacco stalk.
3. The method of claim 1 , wherein the tobacco input comprises reconstituted tobacco.
4. The method of claim 1 , further comprising drying the tobacco input prior to chemical pulping the tobacco input.
5. The method of claim 1 , further comprising depithing the tobacco input prior to chemical pulping the tobacco input.
6. The method of claim 1 , further comprising milling the tobacco input prior to chemical pulping the tobacco input.
7. The method of claim 1 , further comprising mixing water with the tobacco pulp to form a slurry;
filtering the slurry with a filter such that a portion of the tobacco pulp is removed.
8. The method of claim 7 , wherein the filter defines a plurality of apertures having a maximum dimension up to 0.01 inches.
9. The method of claim 7 , wherein filtering the slurry comprises receiving a first portion of the tobacco pulp through the filter and receiving a second portion of the tobacco pulp through the filter after receiving the first portion, wherein at least the second portion of the tobacco pulp is subjected to the bleaching.
10. The method of claim 9 , wherein the strong base employed in chemical pulping the tobacco input defines a weight from about 30% to about 40% of the tobacco input.
11. The method of claim 9 , wherein the H-factor is from about 900 to about 1,100.
12. The method of claim 7 , further comprising removing at least a portion of the water from the tobacco pulp received through the filter prior to the bleaching.
13. The method of claim 7 , wherein the portion of the tobacco pulp that is removed defines a weight that is greater than about 25% of the tobacco pulp prior to filtering.
14. The method of claim 7 , wherein the strong base employed in chemical pulping the tobacco input defines a weight that is less than about 30% of the tobacco input.
15. The method of claim 14 , wherein the H-factor is less than about 900.
16. The method of claim 1 , wherein the strong base employed in chemical pulping the tobacco input defines a weight that is greater than about 40% of the tobacco input.
17. The method of claim 16 , wherein the H-factor is greater than about 900.
18. The method of claim 1 , wherein bleaching the tobacco pulp comprises:
chlorination of the tobacco pulp with a chlorine dioxide solution, and
caustic extraction of the tobacco pulp with a second strong base.
19. The method of claim 18 , wherein chlorination of the tobacco pulp with a chlorine dioxide solution comprises in situ acidification of sodium chlorite.
20. The method of claim 18 , further comprising neutralizing a remaining portion of the chlorine dioxide solution with sodium sulfite.
21. The method of claim 18 , further comprising agitating the tobacco pulp during the chlorination of the tobacco pulp with the chlorine dioxide solution.
22. The method of claim 18 , wherein bleaching the tobacco pulp to produce the dissolving grade pulp is conducted in an ordered sequence comprising:
chlorination of the tobacco pulp with the chlorine dioxide solution,
caustic extraction of the tobacco pulp with the second strong base, and
chlorination of the tobacco pulp with a second chlorine dioxide solution.
23. The method of claim 18 , wherein bleaching the tobacco pulp to produce the dissolving grade pulp is conducted in an ordered sequence comprising:
chlorination of the tobacco pulp with the chlorine dioxide solution,
caustic extraction of the tobacco pulp with the second strong base,
chlorination of the tobacco pulp with a second chlorine dioxide solution, and
chlorination of the tobacco pulp with a third chlorine dioxide solution.
24. The method of claim 18 , wherein the chlorine dioxide solution comprises sulfuric acid.
25. The method of claim 1 , further comprising boiling the dissolving grade pulp in the presence of hydrochloric acid to produce a boiled dissolving grade pulp.
26. The method of claim 25 , further comprising filtering a microcrystalline cellulose residue from the boiled dissolving grade pulp.
27. The method of claim 26 , further comprising drying and milling the microcrystalline residue to produce a microcrystalline powder.
28. The method of claim 1 , wherein the tobacco input and the strong base are heated to a maximum temperature from about 150° C. to about 180° C.
29. The method of claim 1 , wherein chemical pulping the tobacco input is conducted in a pressurized vessel.
30. The method of claim 29 , further comprising agitating the tobacco input in the vessel.