Levin, PatrickPatrickLevinBuchholz, MoritzMoritzBuchholzMeunier, VincentVincentMeunierKessler, UlrichUlrichKesslerPalzer, StefanStefanPalzerHeinrich, StefanStefanHeinrich2022-03-282022-03-282022-03-11Processes 10 (3): 548 (2022)http://hdl.handle.net/11420/12120Freeze-drying is generally used to achieve high quality products and preserve thermal sensitive components; however, it is also considered as a high energy and costly process. Modeling of the process can help to optimize the process to reduce these drawbacks. In this work, a mathematical model is presented to predict the heat and mass transfer behavior for freeze-drying of porous frozen food particles during freeze-drying to optimize the process. For the mass transfer, a comparison between Knudsen diffusion and the more complex dusty-gas approach is performed. Simulation results of a single particle are validated by experiments of single-layer drying to extend the usage of this model from a single particle to a particle bed. For the moisture transfer, adaption parameters are introduced and evaluated. A comparison shows a good agreement of the model with experimental results. The results furthermore suggest a strong correlation of the drying kinetics with pore size and particle porosity. An increase in the pore diameter strongly improves the overall mass transfer rates and hence is a suitable parameter for an effective increase of the drying rates in freeze-drying.Freeze-drying is generally used to achieve high quality products and preserve thermal sensitive components; however, it is also considered as a high energy and costly process. Modeling of the process can help to optimize the process to reduce these drawbacks. In this work, a mathematical model is presented to predict the heat and mass transfer behavior for freeze-drying of porous frozen food particles during freeze-drying to optimize the process. For the mass transfer, a comparison between Knudsen diffusion and the more complex dusty-gas approach is performed. Simulation results of a single particle are validated by experiments of single-layer drying to extend the usage of this model from a single particle to a particle bed. For the moisture transfer, adaption parameters are introduced and evaluated. A comparison shows a good agreement of the model with experimental results. The results furthermore suggest a strong correlation of the drying kinetics with pore size and particle porosity. An increase in the pore diameter strongly improves the overall mass transfer rates and hence is a suitable parameter for an effective increase of the drying rates in freeze-drying.en2227-971720223Multidisciplinary Digital Publishing Institutehttps://creativecommons.org/licenses/by/4.0/freeze-dryingdrying of frozen particlesmodelingdusty gas modelimprovement of mass transferinternal porous structureTechnikIngenieurwissenschaftenIndustrielle FertigungJournal Article2022-03-2410.15480/882.426110.3390/pr1003054810.15480/882.4261Other