Network model for thermal conversion of heterogeneous biomass granules

Abstract

The focus of this research is on the development of a network model for efficient simulation of the thermal conversion of heterogeneous biomass granules during gasification or combustion processes. The network model for heat and mass transport in a porous medium is constructed, which treats heterogeneous constituents of granules (such as wood and straw) as nodes and common surfaces as edges connect them and allow heat and mass to be transported. Reactions with Arrhenius kinetics are used to model the thermal decomposition of biomass. The gas is assumed to be an incompressible ideal gas flowing through a porous medium. A pressure correction scheme is used to model the mass transfer. Conductive and convective heat transfer equations with source terms are used for temperature modeling. Examples in 2D and 3D are presented. This network model can be used as a module in more complex biomass conversion models, such as the Lagrangian particle model in combination with the Eulerian model for fluid dynamics. Improved understanding of these complex processes contributes to enhancing the use of renewable resources, such as wood, straw, peat, for a variety of industry and household applications, leading to more carbon -neutral economy, as well as greater use of local resources.

Study of biomass pellet network model for heat and mass transport in porous media through gas channels

“…In this experiment, our developed model was compared with the ordinary differential equation on the graph from the previous [12], based on the equation: The same initial conditions were given to both solutions -zero values and non-zero boundary conditions at two external nodes, that is, at the 12th vertex with the value -1 and at the 14th vertex with the value 1, at the 14th and 15th vertices there are zeros. Since the parameter τ is vital because it represents the relaxation time, we have chosen it with a value of 0.3, allowing the fluctuations to decay quite quickly for both pressure and flow.…”