Detailed structural elucidation of different lignocellulosic biomass types using optimized temperature and time profiles in fractionated Py-GC/MS

Fractionated pyrolysis coupled to gas chromatography and mass spectrometry experiments (Py-GC/MS) were carried out on eight woody and agricultural biomasses, including beech, poplar, pine forest residues, Scot Pine bark, reed canary grass, corn cob, grape seed cake and wheat straw. The selected temperature and duration for each fractionated pyrolysis step allowed separating the volatile pyrolysis products in function of their origin from biomass. As a result, carbohydrate derivatives from hemicelluloses were released at earlier fractionated pyrolysis steps, compared to those produced from cellulose degradation. Phenolic derivatives, mainly produced by lignin, were stepwise produced in function of the length and the nature of their side-chain substituents. Protein derivatives were also released in the whole Py-GC/MS temperature range. Macromolecular composition and biomass family were shown to play a crucial role in the thermal degradation of the biomasses of study. Production profiles exhibited resemblances per chemical species between deciduous and coniferous woods, while they appear to be more heterogeneous for agricultural biomasses. Herbaceous crops showed an intermediate behaviour between woods and agricultural biomasses.