Water-resistant and durable biocarbon pellets, and methods for making and using the same

Abstract

Water-resistant, high-durability, and high-density biocarbon pellets are described. In some variations, a process for producing biocarbon pellets comprises: pyrolyzing a biomass-containing feedstock in a pyrolysis reactor, thereby generating a solid biocarbon-containing material and a pyrolysis vapor; introducing the pyrolysis vapor to a separation system configured to recover a pyrolysis condensate in liquid form separated from non-condensable gases; capturing pyrolysis condensate as a polyphenolic material; contacting the solid biocarbon-containing material with the polyphenolic material, thereby generating an intermediate mixture; introducing the intermediate mixture to a densification unit, thereby generating a biocarbon pellet precursor; and at least partially drying the biocarbon pellet precursor, thereby generating biocarbon pellets characterized by a 24-hour water uptake of about 20 wt % or less, measured at 25° C. and 1 bar. The biocarbon pellets can be stockpiled outside, which is logistically convenient at manufacturing sites, such as industrial metal-making plants that feed the biocarbon pellets into the process.