Abstract
Biomass gasification is a complex process, influenced by various parameters. Numerous models have been developed in order to describe the process of biomass gasification, a respectable amount of which concern the specific case of downdraft gasifiers. A traditional “blackbox” modeling approach cannot reflect the wide range of operational conditions and the four major different process zones (i.e. drying, pyrolysis, oxidation, reduction) in a downdraft gasifier. Intermediate reactions, as the char –gas reactions act as nested ‘niches’, the equilibrium of which defines drastically the composition of the final products. This procedure could be named as a “multibox” approach, where every box contains a thermodynamic intermediate equilibrium. The current model is developed in Matlab Cantera environment and applies the method of element potential minimization and the Villars–Cruise–Smith (VCS) algorithm. The aim of the present work is to assess the performance of the “multibox”, by inserting real operating data (i.e. biomass composition, equivalent ratio, operation temperatures), collected during a monitoring activity that have been performed by the authors on a downdraft gasifier (design: JoosGasifier), in North Italy. The values that are returned from the model are compared with the actual measurements.