Effects of Hydrothermal Processing on Miscanthus × giganteus Polysaccharides: A Kinetic Assessment

Polymers (Basel). 2022 Nov 4;14(21):4732. doi: 10.3390/polym14214732.

Abstract

Miscanthus × giganteus samples were characterized for composition and treated with hot compressed water (hydrothermal or autohydrolysis treatments) at temperatures in the range of 190-240 °C. The liquid phases from treatments were analyzed to assess the breakdown of susceptible polysaccharides into a scope of soluble intermediates and reaction products. The experimental concentration profiles determined for the target compounds (monosaccharides, higher saccharides, acetic acid and sugar-decomposition products) were interpreted using a pseudohomogeneous kinetic mechanism involving 27 reactions, which were governed by kinetic coefficients showing an Arrhenius-type temperature dependence. The corresponding activation energies were calculated and compared with data from the literature. The kinetic equations allowed a quantitative assessment of the experimental results, providing key information for process simulation and evaluation.

Keywords: Miscanthus; autohydrolysis; kinetic modeling; polysaccharides; value-added compounds.