Estudo da pirólise do bagaço da cana-de-açucar em leito de jorro: modelagem, simulação e otimização CFD.

Abstract

Brazil is the world’s largest sugarcane producer, and its bagasse is a significant source of biomass that can be converted into renewable energy through processes like pyrolysis. Developing mathematical models to represent this process is crucial for optimization. In this context, this study assessed how the injection location of biomass particles and operational parameters affect the conversion rates of pyrolysis reactions in a fluidized bed. To achieve this, a Computational Fluid Dynamics (CFD) model with an Eulerian-Lagrangian approach was proposed and simulated using OpenFOAM. Initially, single-particle pyrolysis was simulated with a two-stage semi-global kinetic mechanism. Subsequently, the kinetic mechanism was modified to account for biomass composition. In the third phase, the behavior of the inert particle bed was simulated, validating the proposed model through these three steps. With this model in hand, different biomass injection locations were explored. Based on the optimal geometric configuration, a numerical factorial 2k design of experiments (DoE) was conducted to investigate the influence of gas temperature, gas velocity, and biomass particle diameter on pyrolysis reactions. Numerical results were compared and validated against experimental data reported in the literature. Regarding the reactor’s geometric configuration, the entry point near the base of the equipment yielded the best results. In terms of the DoE, it was observed that temperature and particle diameter significantly influence reaction behavior. Ultimately, the highest biomass conversion scenario was achieved at a temperature of 600°C, gas velocity of 142 m/s, and biomass particle diameter of 1.0x10−3 m, resulting in a conversion rate of 84.35%.