US 11,952,548 B2
Systems, methods and techniques for torrefaction
Ezra Bar-Ziv, Atlantic Mine, MI (US); Stas Zinchik, Hancock, MI (US); and Shreyas Sunil Kolapkar, Houghton, MI (US)
Assigned to MICHIGAN TECHNOLOGICAL UNIVERSITY, Houghton, MI (US)
Filed by MICHIGAN TECHNOLOGICAL UNIVERSITY, Houghton, MI (US)
Filed on Mar. 14, 2022, as Appl. No. 17/693,825.
Claims priority of provisional application 63/225,619, filed on Jul. 26, 2021.
Prior Publication US 2023/0032047 A1, Feb. 2, 2023
Int. Cl. C10L 9/08 (2006.01); C10L 5/40 (2006.01); C10L 5/36 (2006.01)
CPC C10L 9/083 (2013.01) [C10L 5/406 (2013.01); C10L 5/363 (2013.01); C10L 2200/0461 (2013.01); C10L 2200/0469 (2013.01); C10L 2290/28 (2013.01); C10L 2290/30 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method for operating a system for torrefaction of waste material comprising biogenic and plastic material, the method comprising:
processing the waste material to generate a coarse size waste material, the coarse size waste material having a size no greater than 310 mm;
processing the coarse size waste material to generate a fine size waste material, the fine size waste material having a size no greater than 60 mm;
processing the fine size waste material to generate pre-processed waste material, comprising: operating a shredding unit at a speed less than 500 rpm
the pre-processed waste material having an aspect ratio between 0.8:1 and 1.2:1 and a largest dimension of less than 4 millimeters (mm);
wherein a density of the pre-processed waste material is between 105 kg/m3 and 120 kg/m3;
receiving the pre-processed waste material in an airlock;
providing the pre-processed waste material from the airlock to a heating and compaction unit;
compressing and heating the pre-processed waste material in the heating and compaction unit, including heating the heating and compaction unit to a temperature between 180° C. and 220° C.;
providing the compacted waste material to a reactor system such that a residence time in the reactor system is between 2 minutes and 30 minutes;
heating the compacted waste material in the reactor system to a temperature of 280° C.-500° C.;
extruding material from the reactor system; and
cutting the extruded material into pellets.