Structural elucidation of hydro-products from hydrothermal carbonization of loblolly pine at different temperatures using NMR techniques

Solid products from HTC were condensed carbon materials consist of lignin/pseudo-lignin and furfural structures with low carbonyl and carboxyl content, protonated carbon percentage in aromatic structure is higher than un-protonated carbon in aromatic structures, methoxy content reduced at higher temperature while aliphatic side-chains content increased; Liquid chemicals were water-soluble products consist of condensed polyaromatic structure with an elevated content of carbonyl and carboxyl groups, un-protonated carbon in aromatic structures show higher percentage, methoxy content increased at higher temperature while aliphatic side-chains content decreased, free phenol hydroxyl are richer than C5 substituted condensed phenolic OH.