It has been discovered that waste cross-linked polymer materials both synthetic (scrap tire rubber, used polyurethane, and epoxy and phenol resins in discarded printed circuit boards) and natural (wood biomass, keratin, and chitin) can be conveniently depolymerized at slightly elevated temperatures and moderate pressures by the action of a liquid chemical reagent. The proposed inexpensive process results in a substantial to total depolymerization of synthetic polymers and thereby recovers valuable liquid and solid materials. When applied to lignocellulosic biomass, the proposed process, depending on the reaction conditions, either unlocks the lignin-hemicellulose matrix making cellulose more available for fermenting microorganisms or results in carbonization, or coalification of the biomass that may be desirable in terms of sequestering excessive carbon from the Earth's biosphere.
