Advances in the Characterization Methods of Biomass Pyrolysis Products

Biomass is a renewable resource that currently accounts for 10% of the total global energy load. Thermochemical technologies, particularly pyrolysis, are widely used in biomass conversion due to their high reaction and conversion rates compared with biochemical transformation. Understanding the pyrolysis process and the properties of pyrolytic products is essential to obtain further valorized pyrolytic products, such as bio-oil-based chemicals and biochar-based carbonaceous materials. Thus, fully characterizing pyrolysis and its products is imperative. This review focuses on recent advances in pyrolysis-characterization methods, particularly on the online characterization of biomass pyrolytic intermediates and spectroscopic and microscopic imaging methods for biochar and bio-oil. We further discuss how these characterizations help elucidate the pyrolysis mechanism and extend the utilization of pyrolytic products. The drawbacks and improvement prospects of current methods are also discussed.