Mass Transfer in Oil Sand Fluidized Beds—A Simplified Model

1988 ◽  
Vol 110 (4) ◽  
pp. 279-283
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Closed Form ◽  
Fluidized Bed ◽  
Oil Sands ◽  
Fluidized Beds ◽  
Spherical Particles ◽  
Simplified Model ◽  
Oil Sand ◽  
Uniform Velocity

Experimental data obtained previously relating to the behavior of single spherical particles of oil sands in hot uniform velocity oxidizing gaseous streams were employed and extended to estimate in a preliminary fashion the extent of mass transfer from oil sand fragments in a fluidized bed. This has been done through employing experimental correlations published in the literature on fluidization. A simple closed-form analytical expression was derived for estimating the transient rates of mass transfer in fluidized beds of oil sands in terms of the main controlling parameters.

A Study of Mass Transfer Around Oil Sand Fragments in High Temperature Atmospheres

1989 ◽  
Vol 111 (2) ◽  
pp. 97-99
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Reynolds Number ◽  
High Temperature ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oil Sands ◽  
Simple Expression ◽  
Convective Mass Transfer ◽  
Oil Sand

An approximate approach was formulated to estimate the coefficient of convective mass transfer from small preshaped rectangular fragments of oil sands when subjected to hot streams of products of combustion of lean mixtures to hydrogen in air at low Reynolds number and at temperatures up to 1000 K. A simple expression which was derived to correlate the mass transfer coefficient in terms of the connective stream temperature was shown to fit the experimental data well.

Volatilization of Packed Beds of Oil Sand Particles

1987 ◽  
Vol 109 (2) ◽  
pp. 71-74
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Packed Beds ◽  
Oil Sand ◽  
Transfer Coefficients ◽  
Simple Analytical Expression ◽  
Low Reynolds Numbers ◽  
Fixed Beds

Based on a quasi-steady system, published experimental data on mass transfer in packed beds of spherical particles at relatively low Reynolds numbers, were employed to estimate the convective mass-transfer coefficients in the bed in terms of the corresponding values for single particles. The average transient fluid concentrations within the bed of particles were also obtained in terms of the corresponding single-particle concentrations using the lumped-heat-capacity system. Thus, experimental data published on volatilization of single oil sand spheres could then be extended to estimate the rates of volatilization of packed beds of oil sand spheres. A simple analytical expression could, therefore, be derived for estimating the transient mass loss from fixed beds of oil sand spheres in terms of the parameters involved.

scholarly journals Mass transfer between a fluid and an immersed object in liquid-solid packed and fluidized beds

2005 ◽  
Vol 70 (11) ◽  
pp. 1373-1379 ◽  
Author(s):  
Nevenka Boskovic-Vragolovic ◽  
Danica Brzic ◽  
Zeljko Grbavcic
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Benzoic Acid ◽  
Fluidized Beds ◽  
Liquid Velocity ◽  
Spherical Particles ◽  
Flowing Water ◽  
Transfer Rates ◽  
Transfer Data ◽  
Dissolution Method

The mass transfer coefficient between fluid and an immersed sphere in liquid packed and fluidized beds of inert spherical particles have been studied experimentally using a column 40 mm in diameter. The mass transfer data were obtained by studying the transfer of benzoic acid from the immersed sphere to flowing water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of inert glass particles 0.50-2.98 mm in diameter. The influence of different parameters, such as: liquid velocity, particles size and bed void age, on the mass transfer in packed and fluidized beds is presented. The obtained experimental data for mass transfer in the packed and particulate fluidized bed were correlated by a single correlation, thus confirming the similarity between the two systems.

Unsteady Mass Transfer From Oil Sand Spheres in Convective Streams at Low Reynolds Number

1990 ◽  
Vol 112 (4) ◽  
pp. 260-263
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Atmospheric Pressure ◽  
Oil Sands ◽  
Spherical Particles ◽  
Stream Velocity ◽  
Oil Sand ◽  
Experimental Conditions ◽  
Hot Air ◽  
Air Streams

The process of transient mass transfer in and around oil sand spheres was investigated experimentally. Preshaped molded spherical particles of Athabasca oil sands were subjected to hot air streams at atmospheric pressure and constant temperature ranging from 150°C up to 475°C with a uniform stream velocity covering the range 0.15 m/s up to 1.7 m/s and Reynolds number over the range 33–1650. The rate of mass loss due to fluid volatilization for each set of experimental conditions was established and correlated with the residence time in terms of dimensionless groupings.

scholarly journals Mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles

2004 ◽  
Vol 58 (2) ◽  
pp. 69-72
Author(s):  
Danica Brzic ◽  
Nevenka Boskovic-Vragolovic ◽  
Zeljko Grbavcic
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Benzoic Acid ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Single Phase ◽  
Spherical Particles ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Transfer Coefficients

Mass transfer in fluidized beds is an important operation for separation processes. Two effects can be achieved by using fluidized beds in mass transfer processes increasing interface area and relative movement between the phases. These effects are both desirable because they lead to greater process rates. This paper presents an experimental investigation regarding mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles. The experiments were conducted in column 40 mm in diameter with spherical particles 0,8-3 mm in diameter and water as one fluidizing fluid. The method of dissolution of benzoic acid was used to provide very low mass flux. The average wall-to-fluid mass transfer coefficients were determined for two systems: single-phase fluid flow and a fluidized bed of inert particles The measurements encompassed a Reynolds number range from 100-4000 for single-phase flow and 600-4000 in fluidized beds. The mass transfer coefficients for both systems were calculated from weight loss of benzoic acid. The effects of superficial liquid velocity and particle diameter on the mass transfer coefficient were investigated. It was found that mass transfer was more intensive in the fluidized bed in comparison with single phase flow. The best conditions for mass transfer were reached at a minimum fluidization velocity, when the mass transfer coefficient had the greatest value. The experimental data were correlated in the form: jd = f(Re), where jd is the dimensionless mass transfer factor and Re the Reynolds number.

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.

Heat Transfer in the Flow of Gases Around Oil Sand Spheres

1988 ◽  
Vol 110 (4) ◽  
pp. 276-278
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Heat Transfer ◽  
Oil Sands ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Dimensionless Temperature ◽  
Convective System ◽  
Oil Sand ◽  
Low Reynolds Numbers ◽  
Convection Heating ◽  
Free And Forced Convection

An experimental study was conducted for the combined free and forced convection heating of preshaped molded spherical particles of Athabasca oil sands in hot gaseous streams of air at low Reynolds numbers. Based on a quasi-steady system, the lumped-heat-capacity approximation was employed to estimate the heat transfer coefficient of the transient convective system for each prescribed set of experimental stream conditions. Correlation of the results was made in terms of the dimensionless Nusselt number as a function of the particle Reynolds number and a dimensionless temperature difference. The simple closed-form analytical expression of the correlation was shown to fit the experimental data well.

Prediction of the Flotsam Component in a Gas-Fluidized Bed of Two Dissimilar Solids

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Alberto Di Renzo ◽  
Francesco P. Di Maio ◽  
Vincenzino Vivacqua
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Simple Model ◽  
Discrete Element Method ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Computational Simulations ◽  
The Difference ◽  
Gas Fluidized Beds

In the present paper the segregating behaviour of solids of different size and density in gas-fluidized beds is studied. In particular, the attention is focussed on pairs composed of a bigger/less dense species and a smaller/denser species. Typical industrial examples of such combinations are encountered in fluidized beds of biomass/sand mixtures. Their behaviour is not easily predictable, as the segregation tendency promoted by the difference in density is counteracted by the difference in size. While typically the denser component is expected to appear predominantly at the bottom of the fluidized bed, experiments on mixtures exhibiting the reverse behaviour have been reported (e.g. Chiba et al., 1980).A simple model to predict the segregation direction of the components, i.e. which species will segregate to the top of the bed (the flotsam), depending upon their difference in properties (size, density) and the mixture composition, is discussed. The predicted behaviour is compared with experimental data available in the literature and agreement is found for the majority of them. For one mixture, experiments are conducted as well as computational simulations based on the combined Discrete Element Method and Computational Fluid Dynamics (DEM-CFD) approach. This allows investigating how an initially mixed bed upon suspension evolves as a result of the segregation prevalence in the bed.

scholarly journals A novel two-phase model for bubbling fluidized-bed CO-methanation reactor

2020 ◽  
Author(s):  
Quancong Zhang ◽  
Zhikai Cao ◽  
Songshou Ye ◽  
Yong Sha ◽  
Bing Hui Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Gas Flow ◽  
Flow Distribution ◽  
Co Methanation ◽  
Interphase Mass Transfer ◽  
Proposed Model

Fluidized bed reactor is promising for CO methanation owing to its excellent heat transfer performance. The gas flow distribution between the bubble and emulsion phases and mass transfer are important for such a solid-catalyzed fast reaction in fluidized bed but these are described simplistically in most conventional models. In this work, a novel model contemplating the gas flow distribution influenced by circulation flow and the interphase mass transfer coefficient influenced by bubble size variation is proposed. The simulation results of the proposed model and the classic Kunii–Levenspiel model were compared with experimental data of fluidized bed CO methanation. It was shown that the results of the proposed model have better agreement with experimental data. To evaluate the roles of gas flow distribution and interphase mass transfer coefficient, sensitivity analysis was carried out. The results indicated that in the proposed model, the effect of gas flow distribution is more important.

scholarly journals Mass Transfer Enhancement in GLS Fluidized Beds using Nanomaterials

2019 ◽  
Vol 8 (3) ◽  
pp. 5763-5766
Keyword(s):  
Mass Transfer ◽  
Benzoic Acid ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Physical Property ◽  
Gas Velocity ◽  
Three Phase ◽  
Unique Physical Property

Nanomaterial has unique physical property which made it important for many applications and that is why the use of nanomaterials rapidly increasing in the field of science and engineering.1 . This work focuses on mass transfer of solids into liquid in three phase fluidized beds in presence of nanomaterial. This include the study of effect of gas velocity, time and different concentration of nanomaterials on mass transfer coefficient in stagnant liquid column in three phase fluidized bed system. To measure coefficient of the mass transfer, known quantity of solid pellets ie benzoic acid and known amount of nanomaterial fraction ie Arachitol nano were charged in the test column of three phase fluidized bed system. At the beginning of each run, test section was partially filled with water which prevent breakage of particles. The experiments were conducted by sequentially varying gas velocity for different volumes of nanomaterial and measuring the rate of mass transfer by collecting samples directly from the outlet ports at the top subsequently analysed by volumetric titration method. The results show enhancement in mass transfer coefficient by addition of nanomaterials. Arachitol nano has been taken in different volumes ie 3ml, 7ml, 10ml and 20ml in (GLS) gas ,liquid and solid fluidized bed with air, water and benzoic acid pellets as three phases respectively in the system. The presence of nanomaterial increases the solid liquid mass transfer coefficient value with increasing fraction of nanomaterial, increasing gas velocity and increasing time although experimental run has been taken only for one hour.

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