Abstract
In order to decrease anthropogenic CO2 emissions and to become independent from fossil resources, one alternative for energy generation and production of platform-chemicals is the usage of biomass. There are multiple process routes for the exploitation of biomass for energetic or material usage. For biomass with low water content, thermo-chemical conversion such as pyrolysis, gasification or combustion is the preferred treatment to gain energy or material products. The challenges in this field are to reduce unwanted emission of pollutants from the conversion process and to design devices that achieve high conversion efficiency. Simulations of the biomass conversion processes inside reactors are a valuable tool to overcome those challenges. Apart from the usage in industrial applications, there are models that have a high level of detail including complex reaction mechanisms for the decomposition of the biomass and advanced description of the physical changes of the biomass structure during thermo-chemical conversion. They help to deepen the understanding of the conversion process. However, for most commercial simulation software, biomass conversion remains a niche application, and models have to be implemented to simulate the process correctly.
In this study, the pyrolysis behaviour of beech wood particles was simulated with a three-dimensional modelling approach in the open source computational fluid dynamics (CFD) software OpenFOAM. The implementation of the model included the biomass as porous reacting medium that changed the chemical composition and the solid properties during pyrolysis due to decomposition reactions. This modelling approach can in the future be used for the simulation of devices for thermo-chemical conversion of biomass with a fixed bed such as wood burning stoves or gasifiers. On the other hand, the model will be further developed to investigate the thermo-chemical conversion on a very detailed level with complex chemical and physical models, also considering the anisotropic structure of the biomass.
