Autor(es): Torrado, Ivone ; Neves, Beatriz Guapo ; Fernandes, Maria da Conceição ; Carvalheiro, Florbela ; Pereira, Helena ; Duarte, Luís C.
Data: 2024
Identificador Persistente: http://hdl.handle.net/10400.5/96357
Origem: Repositório da Universidade de Lisboa
Assunto(s): biorefineries; fractionation; hemicelluloses; microwave heating; Pinus pinae; severity factor
Pine nut shells, a biomass residue from the Mediterranean Pinus pinea pine nut industrial processing, were treated by microwave- assisted autohydrolysis to produce xylo-oligosaccharides. Microwave-assisted processes provide alternative heating that may reduce energy input and increase overall process efficiency. The autohydrolysis treatments were performed under isothermal and non-isothermal operations within a wide range of operational conditions (temperature/reaction times) covering several severity regimes (as measured by the log R0 severity factor). The composition of the autohydrolysis liquors was determined in terms of oligo- and monosaccharides, aliphatic acids and degradation compounds. The process was highly selective towards hemicelluloses hydrolysis and liquid streams containing a mixture of oligomeric compounds (mainly xylooligosaccharides) could be obtained under relatively mild operation conditions (190 °C, 30 min) with a maximal oligosaccharides’ concentration of 18.48 g/L. The average polymerization degree of the obtained oligosaccharides was characterised by HPLC, showing that for the optimal conditions a mixture of oligomers with DPs from 2 to 6.
