Fluidization XVI
Plenary Talk: A Multistage fluidized bed reactor: Stability analysis, Suppression of back-mixing and its application in heterogeneous catalysis
Author
Wei, F. - Presenter, Tsinghua University
Fluidized bed reactors have been widely applied in physical and chemical industries due to its easy fluidity and considerable heat and mass transfer capability. For its fluidity, since solids bed has highly inelastic energy dissipation, mal-distribution always occurs in dilute and dense fluidization [1,2]. A criterion, based on direct Lyapunov method, for predicting instability of uniform gas solids distribution is obtained to design a robust fluidized bed reactor [3]. Additionally, fluidized bed reactors with considerable transfer capability also have some inherent drawbacks like a high degree of gas solids back-mixing. It becomes a barrier to the application of fluidized beds to heterogeneous catalytic process, especially with the intermediates as the desired products. Therefore, the strategy, in the advantage of phase separation through a nozzle, to suppress gas solids backing to obtain plug-flow performance with narrow residence time distribution is a requirement for advanced gas solids reactors [4]. A review of the fundamental research as well as industrial applications on the stability analysis in uniform fluidization and multi-stage fluidized beds to inhibit gas solids back-mixing in the Fluidization Laboratory of Tsinghua University (FLOTU) will be provided.
[1] Chenxi Zhang, Weizhong Qian, Fei Wei, et al. AIChE J. 2016, 62: 4251.
[2] Chenxi Zhang, Weizhong Qian, Fei Wei. Chem Eng Sci. 2017, 173: 187.
[3] Chenxi Zhang, Weizhong Qian, Fei Wei, et al. Chem Eng Sci. 2018, 176: 515.
[4] Chenxi Zhang, Yao Wang, Fei Wei, et al. Can J Chem Eng. 2019. (Issue highlights).