scholarly journals Adsorption of Congo red Dye from Aqueous Solution onto Wheat Husk in a Fluidized Bed Reactor

2019 ◽  
Vol 20 (4) ◽  
pp. 55-60
Author(s):  
Israa Sabah ◽  
Abeer I. Alwared
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Congo Red ◽  
Mass Transfer Rate ◽  
Particle Diameter ◽  
Fluidized Bed Reactor ◽  
Breakthrough Curves ◽  
Operating Conditions ◽  
Wheat Husk

The purpose of this paper is to examine absorbance for the removal of the Red Congo using wheat husk as a biological pesticide. Several experiments have been conducted with the aim of configuring breakthrough data in a fluidized bed reactor. The minimum fluidized velocities of the bed were found to be 0.031 mm/s for mish sizes of (250) µm diameter with study the mass transfer be calculated KL values. The results showed a well-fitting with the experimental data. Different operating conditions were selected: bed height (2, 5 and 10) cm, flow rate (90, 100and 120) ml/sec and particle diameter (250, 600, 1000) µm. The breakthrough curves were plotted for Congo Red, Values showed that the lower the bed, the lower the number of adsorbents and the potential of the weak bed to condense the density of the solution, which also increases the flow rate and will increase the mass transfer rate.

scholarly journals Removal of Congo Red from Aqueous Solution by Circulating Fluidized Bed(CFB)

2021 ◽  
Vol 28 (2) ◽  
pp. 01-07
Author(s):  
Hamza Q. Ali ◽  
Ahmed A. Mohammed
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Congo Red ◽  
Circulating Fluidized Bed ◽  
Mass Transfer Rate ◽  
Breakthrough Curves ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Bed Height

In this study circulating fluidized bed was adopted to remove of Congo Red from wastewater using Eichhornia crassipes as a adsorbent. Solution flow rate(6,12 and 18)l/hr, bed height(2,4 and 6) cm and Congo Red initaial concentration (10,25 and 50)mg/l were examined in experiments to show their effects on breakthrough curves and time required to reach the adsorbent to fully saturated curve. The mass transfer coefficient "KL"decreased with decreasing the liquid flow rate. The minimum fluidization velocities of bed found equal to 1.6, 2, 2.5 mm/s for heights of 2, 4,6 cm respectively. The increasing of the bed height will increase the contact time of the solute in the bed, and these improve the solute removal efficiency. the increasing in flow rate and initial concentration will increase the mass transfer rate.

Theoretical Analysis of Fluidized-Bed Reactor for Dimethyl Ether Synthesis from Syngas

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Wen-Zhi Lu ◽  
Li-Hua Teng ◽  
Wen-De Xiao
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Dimethyl Ether ◽  
Fixed Bed ◽  
Fluidized Bed Reactor ◽  
Slurry Reactor ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Dme Synthesis ◽  
Co Conversion

Dimethyl ether (DME) is regarded as an environmentally benign fuel for vehicles. Two kinds of reactor technologies for DME synthesis have been proposed by previous researchers: the fixed-bed and the slurry reactor. As the reactions are highly exothermic and the temperature window of the catalyst is very narrow, the fixed-bed reactor provides a limited heat removal capability and a low conversion of the syngas. The slurry reactor can provide an effective temperature control but a very high inter-phase mass transfer resistance is added by the liquid medium. The Fluidized bed reactor can be an ideal reactor for DME synthesis as it possesses both high heat and mass transfer efficiencies. In this paper, a two-phase model is used to theoretically analyze the DME synthesis in a fluidized bed reactor, with both phases assumed to be in plug flow and taking into account the changes in bubble diameter resulting from the reaction. Three reactions take place simultaneously when DME is manufactured from the syngas (H2 + CO): a) CO+2H2 = CH3OH; b) 2CH3OH = DME+H2O; and c) CO+H2O = CO2+H2. The simulation shows that, at the reactor outlet, the equilibrium approaches of the three reactions are 0.32, 0.1, and 0.61, respectively. When H2/CO=1.0, the CO conversion and DME selectivity in a fluidized bed reactor are 62% and 95%, while those in a fixed-bed reactor are 9% and 86%. In a slurry reactor, the CO conversion and DME selectivity are 17% and 70%, respectively. Therefore, the fluidized-bed is the most promising candidate reactor for conducting the DME synthesis from syngas. Effects of the operating conditions on the performance of DME synthesis in the fluidized-bed reactor are discussed in details. The optimal H2/CO ratio is between 1.0-1.5, and increasing the pressure is shown to improve the reactor performance.

scholarly journals Prediction of gas holdup in a combined loop air lift fluidized bed reactor using Newtonian and non-Newtonian liquids

2011 ◽  
Vol 17 (3) ◽  
pp. 375-383
Author(s):  
Sivakumar Venkatachalam ◽  
Akilamudhan Palaniappan ◽  
Senthilkumar Kandasamy ◽  
Kannan Kandasamy
Keyword(s):  
Fluidized Bed ◽  
Particle Diameter ◽  
Fluidized Bed Reactor ◽  
Gas Holdup ◽  
Operating Conditions ◽  
Experimental Results ◽  
Gas Velocity ◽  
Wide Range ◽  
Newtonian Liquids ◽  
Superficial Gas Velocity

Many experiments have been conducted to study the hydrodynamic characteristics of column reactors and loop reactors. In this present work a novel combined loop airlift fluidized bed reactor was developed to study, the effect of superficial gas and liquid velocities, particle diameter, fluid properties on gas holdup by using Newtonian and non-Newtonian liquids. Compressed air was used as gas phase. Water, 5% n-butanol, various concentrations of glycerol (60 % and 80 %) were used as Newtonian liquids, different concentrations of Carboxy Methyl Cellulose (0.25 %, 0.6 % and 1.0 %) aqueous solutions were used as non-Newtonian liquids. Different sizes of Spheres, Bearl saddles and Raschig rings were used as solid phases. From the experimental results it was found that the increase in superficial gas velocity increases the gas holdup, but it decreases with increase in superficial liquid velocity and viscosity of liquids. Based on the experimental results a correlation was developed to predict the gas holdup for Newtonian and non-Newtonian liquids for a wide range of operating conditions at a homogeneous flow regime where the superficial gas velocity is approximately less than 5 cm/s.

scholarly journals CFD Modelling of a Hollow Fibre Membrane for CO2 Removal by Aqueous Amine Solutions of MEA, DEA and MDEA

2016 ◽  
Vol 14 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Sina Gilassi ◽  
Nejat Rahmanian
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Mass Transfer Rate ◽  
Hollow Fibre ◽  
Operating Conditions ◽  
Transfer Model ◽  
Co2 Removal ◽  
Hollow Fibre Membrane ◽  
Fibre Membrane ◽  
Amine Solutions

AbstractA mass transfer model was developed to capture CO2 from a gas mixture in hollow fibre membrane contactors under laminar flow conditions. The axial and radial diffusions through membrane and convection in tube and shell sides with chemical reaction were investigated. COMSOL software was used to numerically solve a system of non-linear equations with boundary conditions by use of the finite element method. Three different amine solutions of monoethanolamine (MEA), diethanolamine (DEA) and n-methyldiethanolamine (MDEA) were chosen as absorbent in lumen to consider the mass transfer rate of CO2 and its removal efficiency. The modelling results were compared with experimental data available in the literature and a good agreement was observed. The CFD results revealed that MEA had the best performance for CO2 removal as compared to DEA and MDEA under various operating conditions due to the different CO2 loading factor of absorbents. Furthermore, efficiency of CO2 removal was highly dependent on the absorbent concentration and flow rate, increasing of the gas flow rate caused a reduction in gas residence time in the shell and consequently declined CO2 mass transfer. The modelling results showed the effect of absorbent concentration on the CO2 mass transfer was improved due to availability of absorbent reactants at the gas-liquid interface.

Breakthrough curves of oil adsorption on novel amorphous carbon thin film

2016 ◽  
Vol 73 (10) ◽  
pp. 2361-2369 ◽  
Author(s):  
M. El-Sayed ◽  
M. Ramzi ◽  
R. Hosny ◽  
M. Fathy ◽  
Th. Abdel Moghny
Keyword(s):  
Thin Film ◽  
Amorphous Carbon ◽  
Flow Rate ◽  
Produced Water ◽  
Breakthrough Curves ◽  
Operating Conditions ◽  
Bed Height ◽  
Carbon Thin Film ◽  
Oil Adsorption ◽  
Amorphous Carbon Thin Film

A novel amorphous carbon thin film (ACTF) was prepared by hydrolyzing wood sawdust and delignificating the residue to obtain cellulose mass that was subjected to react with cobalt silicate nanoparticle as a catalyst under the influence of sudden concentrated sulfuric acid addition at 23 °C. The novel ACTF was obtained in the form of thin films like graphene sheets having winding surface. The prepared ACTF was characterized by Fourier-transform infrared spectrometer, transmission electron microscope (TEM), and Brunauer–Emmett–Teller (BET). The adsorption capacity of ACTF to remove oil from synthetic produced water was evaluated using the incorporation of Thomas and Yoon–Nelson models. The performance study is described through the breakthrough curves concept under relevant operating conditions such as column bed heights (3.8, 5 and 11 mm) and flow rate (0.5, 1 and 1.5 mL.min−1). It was found that the oil uptake mechanism is favoring higher bed height. Also, the highest bed capacity of 700 mg oil/g ACTF was achieved at 5 mm bed height, and 0.5 mL.min−1 flow rate. The results of breakthrough curve for oil adsorption was best described using the Yoon–Nelson model. Finally, the results illustrate that ACTF could be utilized effectively for oil removal from synthetic produced water in a fixed-bed column system.

Characterization of a limestone in a batch fluidized bed reactor for sulfur retention under oxy-fuel operating conditions

2011 ◽  
Vol 5 (5) ◽  
pp. 1190-1198 ◽  
Author(s):  
Luis F. de Diego ◽  
Margarita de las Obras-Loscertales ◽  
Francisco García-Labiano ◽  
Aránzazu Rufas ◽  
Alberto Abad ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Operating Conditions

scholarly journals Effect of Fines Content on Fluidity of FCC Catalysts for Stable Operation of Fluid Catalytic Cracking Unit

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 293 ◽  
Author(s):  
Sung Kim ◽  
Chae Yeo ◽  
Do Lee
Keyword(s):  
Fluidized Bed ◽  
Catalytic Cracking ◽  
Particle Diameter ◽  
Fluidized Bed Reactor ◽  
Fluid Catalytic Cracking ◽  
Stable Operation ◽  
Minimum Fluidization Velocity ◽  
Fines Content ◽  
Fluidization Velocity ◽  
Fcc Catalysts

Effect of fines content (weight % of particles with diameter less than 45 μm) on bed fluidity was determined to get a base for good fluidization quality in the fluid catalytic cracking (FCC) unit. The fines content in equilibrium FCC catalysts (Ecat) from commercial units were controlled by adding or removing the fines to simulate commercial situation. To get the fluidity values (Umb/Umf) of seven different FCC catalysts (2 Ecats and 5 fresh catalysts) and their mixture, minimum fluidization velocity (Umf) and minimum bubbling velocity (Umb) were measured in a fluidized bed reactor (0.05 m ID). The fluidity decreased with loss of fines content and increased with increments of makeup of fresh catalysts or additive with the controlled fines content. The fluidities of catalysts increase with increases of normalized particle diameter variation by the fines addition. The obtained fluidities have been correlated with the fines contents and the catalyst and gas properties. The proposed correlation could guide to keep good catalyst fluidity in the FCC unit.

The Efficiency of Phosphorus Removal of Synthetic Wastewater through Struvite Crystallization in an Aerated Fluidized Bed Reactor

2018 ◽  
Vol 789 ◽  
pp. 59-63
Author(s):  
Susmardi Masti Casoni ◽  
Chandra Wahyu Purnomo ◽  
Muslikhin Hidayat
Keyword(s):  
Fluidized Bed ◽  
Flow Rate ◽  
Phosphorus Removal ◽  
Crystallization Process ◽  
Fluidized Bed Reactor ◽  
Aeration Rate ◽  
Synthetic Wastewater ◽  
Influent Flow ◽  
Mgcl2 Solution ◽  
P Removal

The high organic material contained in wastewater released into the environment asresults of various sources of human activities, such as phosphorus, can cause eutrophication. Thestruvite crystallization in an aerated fluidized bed reactor is one of the methods which able toimprove the efficiency of phosphorus removal. In this study, a mixture of synthetic wastewaters andthe MgCl2 solution was treated in a fluidized bed reactor equipped with aeration to produce thestruvite which can be utilized as a slow release fertilizer. Subsequently, the effect of aeration atdifference influent flow rate was investigated to correlate with the changing of phosphorusconcentration in the reactor effluent. The experiments were conducted for 240 minutes with thevariation of aeration are 0.5 L/min to 1.5 L/min; variation of influent flow rate of syntheticwastewater is 150 ml/min to 350 ml/min, with a constant influent flow rate of MgCl2 solution is 50ml/min. These solutions were maintained at the condition of pH 9. The results showed that theoptimal efficiency of phosphor removal which accounted for 82.5% occurred when the aeration rateof 1.5 L/min in the influent flow rate of 150 ml/min. From these findings, it is revealed that theefficiency of P removal in wastewater is obtained by a crystallization process which utilizing anaerated fluidized bed reactor and by increasing the aeration rate and the reactants contact time.

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