Applications of Analytical Pyrolysis to the Development of Fuels and Chemicals from Biomass

In setting up analytical procedures, sample preparation is a common step which may require the use of toxic or corrosive substances with potential environmental and health hazard. Analytical pyrolysis (Py) coupled with GC-MS is a solventless technique requiring minimal sample preparation and reagent use. Methods based on Py/GC-MS have been developed with a higher degree of “greenness” in comparison to wet analysis (1). Py/GC-MS has been largely applied to the characterisation of complex and heterogeneous macromolecules deriving from the thermal and environmental degradation of biopolymers. Therefore, it represents a valid approach to study the liquid deriving from the thermochemical conversion of biomass (bio-oil) finalised to the production of biofuels and new chemicals (2). However, conventional Py/GC-MS is flawed by several factors (e.g. mass transfer, aerosol formation, memory effects) limiting its ability to provide an overall picture of the molecular composition of bio-oil without the aid of laborious solvent fractionation procedures. To the end of improving Py/GCMS, we have developed a new approach based on SPME sampling of pyrolysis products evolved from the sample heated at sequentially increasing temperatures (stepwise). Stepwise Py/SPME/GC-MS has been applied to the characterisation of complex bio-oils obtained from the thermochemical treatment of microalgae (3). We have now demonstrated that the method can be combined with on-fiber derivatisation expanding its potential to the analysis of polar constituents, such as thermal degradation products of polysaccharide and proteins.