 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Bioreactor Performance and Design of Large Scale Packed-Bed Solid-State Fermentation) ผู้เขียน: ดร.เพ็ญจิตร ศรีนพคุณ, ศาสตราจารย์ ,  Thongchai Srinophakhun สื่อสิ่งพิมพ์:pdf AbstractBioreactor performance and design was investigated by simulating a transient two-dimensional heat transfer model. The model was able to describe the microbial growth and death kinetics and the energy balance in both axial and radial directions at any location in packed-bed solid-state fermentation. The emphasis of heat conduction, convection and the effect of evaporation made the model particularly useful and practical for large-scale investigation in which the overheating is critical. The system was simplified by assuming pseudo-homogeneous and constant values of bed physical and thermal properties. Orthogonal collocation technique was applied to solve the equations. The characteristic of temporal temperature and biomass concentration profiles in two dimensions were predicted. The effects of various design and operating variables on the performance of the 10 m3 were explored, with the aim of identifying strategies to minimize overheating at the top of the bed. Superficial velocity and inlet air temperature were found to have significant effects on the bioreactor performance. Superficial velocities of 0.08 to 0.1 m/s are required for effective convective heat removal. A low inlet air temperature (308 to 312 K) leads to overheating after 10-20 h which cause all organisms to die. The geometric ratios of 1.0 and below minimized overheating problems and lead to high growth rates. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Mathematical Modelling Development of Packed Bed Bioreactors in Solid-State Fermentation) ผู้เขียน:Penjit Sangsurasak, Thongchai Srinophakhun, David A. Mitchell สื่อสิ่งพิมพ์:pdf Abstract A two-dimensional heat transfer model was developed on the microbial growth on starchy materials in packed bed bioreactors. The model comprised of two sets of equations : (i) the growth and death kinetics and (ii) the energy balance. The system is assumed to be pseudo-homogeneous and microbial growth and death are influenced by the system temperature. The model predicts the temporal temperature and biomass concentration profiles at any location of the bed in two dimensions. The model was verified by comparing with experimental data and also with simulating results of a one-dimensional model. The model fitted reasonably well with the experimental data and the comparison of these two models were discussed. From the basis of heat transfer, the model was flexible to various sizes of bioreactors and other microorganisms of packed bed solid-state fermentation. The model was proven to be useful and could be used as an investigated tool on either the bioreactor performance and in control optimization and scale-up. |