Processing paper feedstocks
Methods of processing paper feedstocks are provided, as well as intermediates and products made using such methods. Certain types of paper feedstocks, in particular highly pigmented papers, and/or highly loaded papers such as paper that has been color printed, e.g., magazines, and high basis weight coated papers, e.g., magazine stock, are utilized to produce useful intermediates and products, such as energy, fuels, foods or materials.
1. A method of saccharifying paper feedstock, the method comprising:
providing in a vessel, a slurry comprising a paper feedstock consisting essentially of polycoated paper, water, and an enzyme, the slurry having greater than 20 weight percent solids of the paper feedstock;
drawing slurry material from the vessel and jetting the slurry material into the vessel, while saccharifying at least a portion of the paper feedstock, producing a sugar; and
after saccharification, removing from the slurry material a polymer residue from the polycoated paper.
2. The method of claim 1 , wherein jetting the slurry material comprises providing a jet mixer having a nozzle, and directing the slurry material through the nozzle under pressure.
3. The method of claim 2 , wherein a pump generates the pressure, the nozzle being in fluid communication with the pump.
4. The method of claim 2 , wherein the nozzle comprises a shroud surrounding an impeller, the impeller configured to provide jet flow through the nozzle.
5. The method of claim 1 , wherein jetting the slurry material comprises directing the slurry material through a plurality of nozzles under pressure, the pressure generated by one or more pumps, each of the plurality of nozzles being in fluid communication with at least one of the one or more pumps.
6. The method of claim 1 , wherein jetting the slurry material comprises drawing slurry material through an inlet to a pump, the inlet being in fluid communication with the vessel; and
pumping the slurry material through a nozzle under pressure, the nozzle being in fluid communication with the pump.
7. The method of claim 6 , wherein the pump is located outside of the vessel.
8. The method of claim 6 , wherein the inlet draws slurry material from near the surface of the slurry in the vessel.
9. The method of claim 6 , wherein the inlet draws slurry material from near the bottom surface of the vessel.
10. The method of claim 1 , wherein the slurry material jets into the vessel through a nozzle at a velocity between 5 to 150 meters per second.
11. The method of claim 1 , wherein jetting the slurry material into the vessel, causes a secondary entrained flow of aqueous slurry material in the vessel.
12. The method of claim 1 , wherein jetting the slurry material into the vessel provides effective mixing in the vessel while minimizing damage to the enzyme.
13. The method of claim 1 , wherein the vessel has a flat bottom surface.
14. The method of claim 1 , wherein the vessel has an arcuate bottom surface.
15. The method of claim 1 , wherein the vessel has a volume of at least 4,000 L.
16. The method of claim 1 , wherein the vessel has a volume of at least 40,000 L.
17. The method of claim 1 , wherein the initial solids concentration of the paper feedstock in the slurry is at least 20 weight percent.
18. The method of claim 1 , wherein the paper feedstock comprises paper having a pigment, filler, and/or coating content of at least 20 weight percent.
19. The method of claim 1 , wherein the paper feedstock comprises paper having an ash content of at least 8 weight percent.
20. The method of claim 1 , wherein the paper feedstock has been exposed to irradiation, the irradiation provided by one or more of: an ion beam and an electron beam.
21. The method of claim 20 , wherein the paper feedstock has received at least at least 10 Mrad of irradiation.
22. The method of claim 20 , wherein the paper feedstock has received irradiation at a dose rate of at least 1 Mrad per second.
23. The method of claim 1 , wherein the paper feedstock has been subjected to a physical treatment, the physical treatment effective to reduce the bulk density of the paper feedstock and/or increase the BET surface area of the paper feedstock.
24. The method of claim 1 , wherein the paper feedstock has a bulk density of less than about 0.5 grams per cubic centimeter.
25. The method of claim 1 , wherein the enzyme comprises a cellulase.
26. The method of claim 1 , further comprising fermenting at least a portion of the sugar with a microorganism.
27. The method of claim 26 , wherein the paper feedstock comprises a toxic material and/or a solid inorganic material.
28. The method of claim 27 , wherein the toxic material comprises a pigment and/or an ink.
29. The method of claim 27 , wherein the solid inorganic material comprises a filler, a coating, and/or a pigment.