In this study, the heat transfer and drying process of arabica coffee beans in a batch fluidized bed roaster has been studied. Herein, the discrete element method (DEM) has been used and modified to account for resolved 1D temperature and moisture content profiles within each single coffee bean. This approach has the strength to provide much more information on the global (fluidization, mixing) and local (particle data) level compared to existing coffee roaster models. Therefore, the product quality can be evaluated on-line by many more specific criteria beyond the averaged global particle temperature and moisture content. Instead, information of every single particle is available which includes heat and mass transfer coefficients, its local position inside the bed, collision forces, etc. Furthermore, the overall roaster performance is based on e.g. fluidization stability, mixing efficiency or uniformity of quality properties among all particles. More data are presented to account for a broader coffee bean roasting evaluation. Modeling results are in good agreement with experimental data.

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