Researchers Riccardo Caraccio, Edoardo Cipriano, Alessio Frassoldati, and Tiziano Faravelli from Politecnico di Milano have developed a new numerical model to better understand and optimize biomass pyrolysis, a process crucial for converting organic materials into energy. Their work, published in the journal Fuel, addresses a significant gap in current modeling approaches.
Biomass pyrolysis involves heating organic materials in the absence of oxygen, breaking them down into solid, liquid, and gaseous products. This process is essential for producing bio-oil, syngas, and biochar, which can be used for energy generation and other industrial applications. However, current numerical models often focus on either the solid particle evolution or the surrounding gas-phase dynamics, overlooking the intricate interactions between the two phases.
The researchers proposed a single-grid model that fully resolves both the solid and gas phases without relying on sub-grid-scale correlations. This model uses an Eulerian representation of the two-phase system and employs a Volume-Of-Fluid (VOF) method to track the interface between the biomass and the surrounding gas phase. The model also includes solid-phase pyrolysis reactions and introduces a novel approach to capture the coupling between the evolution of biomass porosity and particle shrinkage. Additionally, it accounts for the anisotropic nature of biomass particles within a multidimensional framework.
The model demonstrates mass conservation and numerical convergence, and extensive validation with experimental data shows excellent agreement in terms of mass and temperature profiles and correct volatiles trends. While the shrinking profiles reveal correct trends, they also highlight the need for a better fundamental understanding of the evolution of the biomass structure.
This advanced modeling approach can aid in the development of more sustainable and efficient pyrolysis processes, which are critical for the energy sector’s transition towards renewable and low-carbon technologies. The researchers have made the code and simulation setups, developed within the open-source Basilisk framework, publicly available to facilitate further research and applications in this field.
Source: Caraccio, R., Cipriano, E., Frassoldati, A., & Faravelli, T. (2023). A volume-of-fluid model for biomass particle pyrolysis. Fuel, 346, 128051.
This article is based on research available at arXiv.