scholarly journals Mass transfer characteristics in a three-phase fluidized bed containing low-density and/or small-size particles.

1990 ◽  
Vol 16 (6) ◽  
pp. 1217-1223 ◽  
Author(s):  
Toshiro Miyahara ◽  
Myung-Sup Lee ◽  
Teruo Takahashi
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Low Density ◽  
Transfer Characteristics ◽  
Three Phase

Determining the Effective Mass Transfer Area in Three-Phase Fluidized Bed with Low Density Inert Solids

2018 ◽  
Vol 70 (11) ◽  
pp. 4040-4046
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Effective Mass ◽  
Fluidized Bed ◽  
Internal Diameter ◽  
Low Density ◽  
Gas Velocity ◽  
Liquid Load ◽  
Three Phase ◽  
Solid Liquid

The absorption process is strongly influenced by the effective mass transfer area. In this study the effective mass transfer area in gas-solid-liquid three-phase fluidized bed was determined, in a fluidizing column having an internal diameter of 0.14 m and a height of 1.10 m. The solid packing is made of plastic hollow spheres of 0.01 m diameter, with 415 m2/m3 geometric area and a density of 170 Kg/m3. The absorption of carbon dioxide from the air-carbon dioxide mixture with molar concentration of 0.05M, 0.08M and 0.1M CO2 into sodium hydroxide aqueous solutions of 0.5N and 1.0 N has been employed as test reaction. The experiments were conducted with liquid load changing from 6.49 to 16.24 m³/(m² h) and gas velocity of 1.1 m/s and 2.1 m/s. It was found that the effective mass transfer area increased both with the increase of the gas velocity and the increase of the liquid spray density. It has been observed that the effective mass transfer area in gas-solid-liquid three-phase fluidized bed absorber is from three to eight times higher than the geometric area of the solid packing. A mathematical correlation has been established in order to predict the effective mass transfer area,under the specified conditions, with a deviation of less than 5%. Keywords: Effective mass transfer area, three-phase fluidized bed with low density inert solid packing, mass transfer model, chemical method, reaction regime

scholarly journals Diffusion models and scale-up

2005 ◽  
Vol 9 (1) ◽  
pp. 43-72 ◽  
Author(s):  
Christo Boyadjiev
Keyword(s):  
Mass Transfer ◽  
Parameter Identification ◽  
Fluidized Bed ◽  
Scale Up ◽  
Catalytic Reactions ◽  
Fluidized Bed Reactors ◽  
Hierarchical Approach ◽  
Model Parameter ◽  
Transfer Processes ◽  
Three Phase

A model for transfer processes in column apparatuses has been done. The model may be modified for different apparatuses as columns with (or without) packet bed, two (or three) phase airlift reactors and fluidized bed reactors. The mass transfer is result of different volume reactions as a chemical, photochemical, biochemical or catalytic, reactions, or interphase. mass transfer. The using of the average velocities and concentration permit to solve the scale-up problems. A hierarchical approach for model parameter identification has been proposed.

Mass transfer characteristics of three-phase monolith reactors

2001 ◽  
Vol 56 (21-22) ◽  
pp. 6015-6023 ◽  
Author(s):  
Michiel T. Kreutzer ◽  
Peng Du ◽  
Johan J. Heiszwolf ◽  
Freek Kapteijn ◽  
Jacob A. Moulijn
Keyword(s):  
Mass Transfer ◽  
Transfer Characteristics ◽  
Three Phase ◽  
Monolith Reactors

Mass transfer between solid particles and liquid in a three phase fluidized bed

1987 ◽  
Vol 65 (2) ◽  
pp. 228-236 ◽  
Author(s):  
A. Prakash ◽  
C. L. Briens ◽  
M. A. Bergougnou
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Solid Particles ◽  
Three Phase

scholarly journals Increasing Gas–Solids Mass Transfer in Fluidized Beds by Application of Confined Fluidization—A Feasibility Study

2019 ◽  
Vol 9 (4) ◽  
pp. 634 ◽  
Author(s):  
Jesper Aronsson ◽  
David Pallarès ◽  
Magnus Rydén ◽  
Anders Lyngfelt
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Cross Flow ◽  
Active Role ◽  
High Density ◽  
Low Density ◽  
Olivine Sand ◽  
Bed Material ◽  
Utility Scale

Fluidized bed applications where the bed material plays an active role in chemical reactions, e.g. chemical looping combustion, have seen an increase in interest over the past decade. When these processes are to be scaled up to industrial or utility scale mass transfer between the gas and solids phases can become a limitation for conversion. Confined fluidized beds were conceptualized for other purposes in the 1960’s but are yet to be applied to these recent technologies. Here it is investigated if they can prove useful to increase mass transfer but also if they are feasible from other perspectives such as pressure drop increase and solids throughflow. Four spherical packing solids, 6.35–25.4 mm in diameter at two different densities, were tested. For mass transfer experiments the fluidizing air was humidified and the water adsorption rate onto silica gel particles acting as fluidizing solids was measured. Olivine sand was used in further experiments measuring segregation of solids and packing, and maximum vertical crossflow of solids. It was found that mass transfer increased by a factor of 1.9–3.8 with packing solids as compared to a non-packed reference. With high-density packing, fluidizing solids voidage inside the packing was found to be up to 58% higher than in a conventional fluidized bed. Low density packing material favoured its flotsam segregation and with it higher fluidization velocities yield better mixing between packing and fluidizing solids. Maximum vertical cross-flow was found to be significantly higher with low density packing that fluidized, than with stationary high-density packing. Conclusively, the prospect of using confined fluidized beds for improving mass transfer looks promising from both performance and practical standpoints.

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