Online experiments and modelling with a detailed reaction scheme of single particle biomass pyrolysis

•Online characterisation of the release of volatiles in single particle pyrolysis.•Good closure of elemental mass balances in experiments.•Presented an improved version of a detailed pyrolysis reaction scheme.•Good predictions for CO, CO2, H2O, CH4, total organic condensables and char.•Deviations are present in the groups in which condensable species are classified.

Detailed reaction schemes and experimental data for the online release of pyrolysis volatiles are required to gain a more fundamental understanding of biomass pyrolysis, which would in turn allow the process to be controlled in a more precise way and the development of more targeted applications. A detailed online characterisation of pyrolysis products has been conducted in single particle experiments with spruce pellets at different temperatures, obtaining a good closure of the elemental mass balances. The yields and online release of CO, CO2, H2O, CH4, other light hydrocarbons and total organic condensable species, as well as char yield and composition, can be predicted with a reasonable accuracy with the application of a single particle model, coupled with a detailed pyrolysis scheme, and a simple one-step scheme for tar cracking. In order to achieve it, improvements have been conducted in the pyrolysis scheme, mainly concerning the release of light hydrocarbons and char yield and composition. Deviations are still present in the different groups in which organic condensable species can be classified.