Fast-growing Paulownia wood fractionation by microwave-assisted hydrothermal treatment: a kinetic assessment

Abstract

Microwave hydrothermal treatment (MHT), a novel advanced technology, was proposed for the fractionation of Paulownia wood (PW) at temperatures ranging 200–230 °C and residence times of 0–50 min, corresponding to severities of 2.93–4.70. This procedure allowed 80% of xylan recovery as xylooligosaccharides and an average of 95% cellulose recovery in the pretreated PW biomass, showing the selectivity of the treatment, that was also compared to conduction–convection heating autohydrolysis. Finally, a kinetic model was proposed for the prediction of PW fractionation using MHT, with the ultimate goal of being applied to a wide range of feedstocks and minimizing the number of parameters used. For that, two strategies were approached, allowing the reduction of 80 to 34 parameters, without significant influence in the kinetic fitting. To the best of our knowledge, this is the first kinetic modelization of MHT of PW, taking into account all the lignocellulosic fractions.