A Dynamic Model of the Hydrodynamics of a Liquid Fluidized Bed

• Published in: Industrial & engineering chemistry research Vol. 33; no. 9; pp. 2151 - 2156
• Main Authors: Asif, Mohammad, Petersen, James N, Kaufman, Eric N, Cosgrove, John M, Scott, Timothy C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.09.1994
• Subjects: 01 COAL, LIGNITE, AND PEAT; Applied sciences; BIODEGRADATION; BIOREACTORS; CARBONACEOUS MATERIALS; Chemical engineering; CHEMICAL REACTIONS; COAL; COAL LIQUEFACTION; DECOMPOSITION; DESIGN; DISSOLUTION; ENERGY SOURCES; Exact sciences and technology; FLUID MECHANICS; Fluidization; FLUIDIZED BEDS; FOSSIL FUELS; FUELS; HYDRODYNAMICS; LIQUEFACTION; MATERIALS; MATHEMATICAL MODELS; MECHANICS; THERMOCHEMICAL PROCESSES 010405 > Coal, Lignite, & Peat > Hydrogenation & Liquefaction; Liquid fluidization; Theoretical study; Hydrodynamics; Experimental study; Dynamic model; Mathematical model; Liquid solid; Modeling
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie00033a018

The efficient design, operation, and scale up of novel fluidized bed bioreactors for direct coal liquefaction require detailed knowledge of reactor axial pressure drop, dispersion of the solid and liquid phases, and the particle size distribution as a function of axial position. In this paper, a fully predictive mathematical description of the hydrodynamics of a liquid fluidized bed, containing no adjustable parameters, is developed. This model is compared with experimental data obtained from a liquid fluidized bed containing finely divided coal particles. The emphasis of this study is the development of a predictive mathematical model to appropriately describe the transient behavior of such systems subject to changes in the liquid superficial velocity. The underlying mathematical treatment of this problem is based on particle mass transport mechanisms of dispersion and convection. The particle velocity responsible for convection and the particle dispersion coefficients were evaluated using correlations developed previously. The comparison of the model predictions with the experimental data for coal fluidized beds shows excellent agreement.