Espèces condensables issues de torréfaction de biomasses lignocellulosiques : caractérisation aux échelles laboratoire et pilote

摘要

Torrefaction is mild thermal treatment carried out between 200 and 300 °C, in an inert atmosphere, improving properties of biomass, in order to use it as a biocombustible. This study focuses on the characterisation of the condensable species released during torrefaction, at laboratory and pilot scale. In the laboratory, some samples of pine, ash wood, miscanthus and wheat straw were torrefied at 250, 280 and 300 °C in a fixed bed reactor. The condensable species were analysed by GC-MS, GC-GC and HPLC-MS. Around a hundred of species were identified, including around twenty were quantified and represented 77 % of the condensable species. At pilot scale, a continuous reactor was designed, improved and characterised to treat several kg.h-1 of biomass. A multi-step recovery system for the condensable species was developped. Torrefaction experiments showed that the condensed fractions had different chemical compositions.