On the development of a wood gasification modelling approach with special emphasis on primary devolatilization and tar formation and destruction phenomena

•A wood air/steam gasification model for fluid bed reactors has been developed.•Novel contributions on the definition of homogeneous reactions and tar evolution are proposed.•Validation of the model was performed against data collected from two experimental publications.•The model is able to reproduce key gasification variables with an acceptable error.•The model provides a satisfactory prediction of tar generation.

Tar generation in biomass gasification still poses a considerable challenge regarding its access to commercial stage. Along with experimental research, it is essential to develop comprehensive models of the process that allow accurate prediction of the resulting syngas composition, as well as tar generation. Traditionally, models have focused on defining heterogeneous reactions of char conversion, devoting limited attention to gas interactions. The present research offers a new wood gasification model for fluidized beds, characterized by a detailed definition of homogeneous reactions, considering both generation and evolution of created tar through oxidation, reforming and thermal cracking. The model succeeds in predicting gas generation, composition and heating value with a relative error similar or lower than analogue existing gasification models, as well as the order of magnitude of tar generation.