Comprehensive CFD modelling of solar fast pyrolysis of beech wood pellets

GAUTHIER DANIEL; SORIA JOSE MIGUEL; GAUTHIER DANIEL; SORIA JOSE MIGUEL; MAZZA GERMAN; FLAMANT GILLES; ASENSIO DANIELA; ZENG KUO; MAZZA GERMAN; ASENSIO DANIELA; FLAMANT GILLES; ZENG KUO

FUEL PROCESSING TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 158 p. 226 - 237

0378-3820

Thepresentwork focuses onthe study of the solar pyrolysis of beechwoodpellets. The biomassdegradationprocess wasmodelled in the CFD (Computational Fluid Dynamics) platformANSYS FLUENT 14.0. The results of simulations were compared to experimental tests conducted in a lab-scale solar reactor in order to validate the CFDmodel. The biomass pyrolysis was carried out at temperatures ranging from 600 to 2000 °C, at two heating rates: 10 and 50 °C/s. This new 2D single particlemodel represents a significant improvement of previous simpler version, not only be- cause it allowsmonitoring the evolution of gas speciation but also because its formulation enables to dealwith dif- ferent types of biomass feedstock. Themodel structure comprises amulti-step complex kinetic framework that involves competitive reactions ?including secondary tar reaction- along with rigorous heat and mass (species) transport inside the particle. On this basis, char, tar and gas predicted yields are compared with experimental data. In addition, the gas com- position (CH4,CO, CO2,H2 and CxHy) is also compared. CFDresults are in good agreementwith the experimental values, validating this approach as a useful tool to predict the products yields and their compositionwhen pyro- lyzing biomass particles. Furthermore, the model can be used when modelling any process where pyrolysis oc- curs and it can even be easily coupled to any reactor scale model.