Abstract
The aim of this work is to develop a gasification model based on the thermodynamic equilibrium approach, able to overcome the issues of the classical equilibrium strategy, that computes the gasification products using the Gibbs energy minimization method at fixed temperature and pressure. The model is applied to describe the gasification process of an open top pilot-scale gasifier placed at the Bioenergy and Biofuel Lab of the Free University of Bolzano. The data used for the tune up of the model have been collected over a period of three years of gasification experiments using several biomasses (wood chips, wood pellet, torrefied pellet and wood pellet mixed with char) at different gasification conditions (from 0.17 up to 0.35 of ER value). In fact, a correction factor has been introduced versus the entire set of experimental data to account for the differences between the theoretical hypothesis implemented in the equilibrium model and the real non-adiabatic system. The model outcomes show a good agreement with the experimental data in terms of parameters of interest for gasification such as producer gas LHV, producer gas yield, char yield and cold gas efficiency. Potential outcomes of this research are, firstly, the characterization of the plant behavior without the need of estimating/measuring the average gasification temperature and secondly, the development of a gasification model suitable for the plant control management and in general able to predict the behavior of fixed-bed gasifier systems.