Experimental validation of a multiphase flow model of a lab-scale fluidized-bed gasification unit

摘要

This paper presents the results of a combined experimental and computational characterization of a biomass gasification process as a carbon neutral technology for power generation and/or green hydrogen production. With the aim to set and validate a computational fluid dynamic (CFD) multiphase flow simulation model based on the MFiX suite - as a support for the design and optimization of advanced reactors for energy purposes - a wide experimental campaign has been carried out with cypress (Cupressus sempervirens) wood chips in a lab-scale bubbling fluidized-bed gasification unit in different operation modes: pyrolysis, air-blown gasification as well as steam gasification of char. In addition, pyrolysis kinetics have been experimentally assessed by thermogravimetric analysis (TGA). This study shows that biomass pyrolysis is characterized by a syngas yield of 0.65-0.66, whereas its gasification allows the production of a syngas (1.73-1.77 Nm(3) per kilogram of fuel) characterized by a lower heating value of about 5 MJ/Nm(3), with a hydrogen concentration between 11.4 and 14.3% by volume (depending on the equivalence ratio). In addition, model used is a good predictive tool that can successfully simulate the process and predict syngas composition with good accuracy, in particular for CO, H-2 and CH4.