Prediction of cluster diameter for a wide range of particles for gas-solid dispersed phase in a fast fluidized-bed reactor

A method for the experimental investigation of gas–solid reactions in a small-scale fluidized bed reactor (FBR) is presented. This methodology enables high heating rates (≈104 K/s), long timescale observation (up to several hours), operation with small fuel particles (≈100 μm), and accurate control of reaction conditions. In this study, the gasification reaction of biomass-based char particles with carbon dioxide–nitrogen gas mixtures is investigated under atmospheric pressure. On varying process temperature and feed-gas composition over a wide range, consistent results are realized (temperature is varied between 1173 and 1373 K, while the CO2 concentration is adjusted in an interval of 20% up to 80%). Carbon conversion curves and reaction rates are established from real-time gas product analysis by FTIR spectrometry through a detailed data analysis procedure. This procedure employs a particle surface-evolution model and accounts for sampling system signal attenuation. The obtained reaction rates are used to demonstrate the determination of kinetic parameters for different kinetic approaches concerning the heterogeneous CO2 gasification (Boudouard reaction). Throughout this study, a comparison of both different surface-evolution models as well as kinetic approaches with experimental results is performed for the inspection of best consistency.

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

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq110401024v ◽

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.

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INVESTIGATION OF THE PROCESS OF OBTAINING PYROCARBON IN AN ELECTROTHERMAL FLUIDIZED BED

Energy Technologies & Resource Saving ◽

10.33070/etars.3.2021.03 ◽

2021 ◽

pp. 32-43

Author(s):

K.V. Simeyko ◽

A.I. Malinouski ◽

S.O. Karsim ◽

M.A. Sydorenko ◽

A.D. Kustovska ◽

...

Keyword(s):

Fluidized Bed ◽

Nuclear Power ◽

Experimental Studies ◽

Pyrolytic Carbon ◽

Fluidized Bed Reactor ◽

Artificial Graphite ◽

Wide Range ◽

Fluidizing Agent ◽

Pyrocarbon Coating ◽

The Heat Balance

Carbon materials with a wide range of performance properties are used in various science, technology, and industry fields. For example, Pyrocarbon has the prospect of being used in nuclear power engineering, special metallurgy, aerospace technologies, heat exchange equipment, medicine, mechanical engineering, reactor building and other industries. The research described in the article aims to study the process of obtaining pyrocarbon in an electrothermal fluidized bed. The research is based on experimental methods of studying the process of obtaining pyrolytic carbon. Pyrocarbon is precipitated during pyrolysis (thermal destruction) of hydrocarbons in an electrothermal fluidized bed reactor. Natural gas was used as a fluidizing agent, and crushed fine electrode graphite of the GE model was used as a fluidized bed. When producing batches of pyrocarbon material, taking into account that the particle size will increase, these particles were crushed and subsequently used as a fluidized bed, thereby replacing graphite with pyrocarbon. As a result of the experimental studies carried out in the reactor with the electrothermal fluidized bed reactor, the batches of pyrocarbon material that were produced based on artificial graphite were produced. Studies using electron microscopy showed a change in the color and structure of the pyrocarbon coating depending on the processing cycle in the electrothermal fluidized bed reactor at temperatures of 900–1200 °C. Diffractometric analysis showed that pyrocarbon was identified in the treated material. Therefore, the adequacy of the method for calculating the heat balance has been confirmed. Bibl. 36, Fig. 7, Table 1.

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HETEROGENEOUS PHOTO-FENTON DEGRADATION OF QUINOLINE WITH A NOVEL INTERNAL CIRCULATING FLUIDIZED-BED REACTOR

Environmental Engineering and Management Journal ◽

10.30638/eemj.2016.228 ◽

2016 ◽

Vol 15 (9) ◽

pp. 2119-2126

Author(s):

Hong You ◽

Ran Zhang ◽

Ting Liu ◽

Donghai Wu ◽

Weiming Wang

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Fluidized Bed Reactor

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Removal of microcystin-LR from drinking water with TiO2-coated activated carbon

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0088 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 21-28

Author(s):

S.-C. Kim ◽

D.-K. Lee

Keyword(s):

Drinking Water ◽

Activated Carbon ◽

Synergistic Effect ◽

Fluidized Bed ◽

Continuous Flow ◽

High Surface ◽

High Surface Area ◽

Fluidized Bed Reactor ◽

Exterior Surface ◽

Tio2 Particles

TiO2-coated granular activated carbon was employed for the removal of toxic microcystin-LR from water. High surface area of the activated carbon provided sites for the adsorption of microcystin-LR, and the adsorbed microcystin-LR migrated continuously onto the surface of TiO2 particles which located mainly at the exterior surface in the vicinity of the entrances of the macropores of the activated carbon. The migrated microcystin-LR was finally degraded into nontoxic products and CO2 very quickly. These combined roles of the activated carbon and TiO2 showed a synergistic effect on the efficient degradation of toxic microcystin-LR. A continuous flow fluidized bed reactor with the TiO2-coated activated carbon could successfully be employed for the efficient photocatalytic of microcystin-LR.

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Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

Water Science & Technology ◽

10.2166/wst.1989.0219 ◽

1989 ◽

Vol 21 (4-5) ◽

pp. 157-165 ◽

Cited By ~ 2

Author(s):

F. Ehlinger ◽

J. M. Audic ◽

G. M. Faup

Keyword(s):

Fluidized Bed ◽

Future Development ◽

Protein Concentration ◽

Specific Activity ◽

Fluidized Bed Reactor ◽

Fluidized Bed Reactors ◽

Support Material ◽

Biofilm Development ◽

Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

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The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

Water Science & Technology ◽

10.2166/wst.1993.0092 ◽

1993 ◽

Vol 28 (2) ◽

pp. 135-144 ◽

Cited By ~ 3

Author(s):

S. Matsui ◽

R. Ikemoto Yamamoto ◽

Y. Tsuchiya ◽

B. Inanc

Keyword(s):

Sulfate Reduction ◽

Fluidized Bed ◽

Kinetic Equations ◽

Fluidized Bed Reactor ◽

Order Reaction ◽

First Order Reaction ◽

First Order ◽

Glucose Decomposition ◽

Reaction Equations ◽

Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

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Experimental Study of Hydrodynamic Characteristics and CO2 Absorption in Producer Gas Using CaO-sand Mixture in a Bubbling Fluidized Bed Reactor

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.2445 ◽

2011 ◽

Vol 9 (1) ◽

Author(s):

M.M. Mahadzir ◽

Z.A. Zainal

Keyword(s):

Experimental Study ◽

Fluidized Bed ◽

Fluidized Bed Reactor ◽

Hydrodynamic Characteristics ◽

Producer Gas ◽

Sand Mixture ◽

Bubbling Fluidized Bed

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Biological granulated activated carbon fluidized bed reactor for atrazine remediation

Water Science & Technology ◽

10.2166/wst.2004.0845 ◽

2004 ◽

Vol 49 (11-12) ◽

pp. 215-222 ◽

Cited By ~ 11

Author(s):

M. Herzberg ◽

C.G. Dosoretz ◽

S. Tarre ◽

M. Beliavski ◽

M. Green

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactor ◽

Batch Adsorption ◽

Pseudomonas Sp ◽

Partial Penetration ◽

Biofilm Carrier ◽

Degradation Rates ◽

Degrading Bacteria ◽

Atrazine Degradation ◽

Granulated Activated Carbon

To show that an adsorbing biofilm carrier (GAC) can be advantageous for atrazine bioremediation over a non-adsorbing carrier, fluidized bed (FB) reactors were operated under atrazine limiting concentrations using Pseudomonas sp. strain ADP as the atrazine degrading bacteria. The following interrelated subjects were investigated: 1) atrazine adsorption to GAC under conditions of atrazine partial penetration in the biofilm, 2) differences in atrazine degradation rates and 3) stability of atrazine biodegradation under non-sterile anoxic conditions in the GAC reactor versus a reactor with a non-adsorbing biofilm carrier. Results from batch adsorption tests together with modeling best described the biofilm as patchy in nature with covered and non-biofilm covered areas. Under conditions of atrazine partial penetration in the biofilm, atrazine adsorption occurs in the non-covered areas and is consequently desorbed at the base of the biofilm substantially increasing the active biofilm surface area. The double flux of atrazine to the biofilm in the GAC reactor results in lower effluent atrazine concentrations as compared to a FB reactor with a non-adsorbing carrier. Moreover, under non-sterile denitrification conditions, atrazine degradation stability was found to be much higher (several months) using GAC as a biofilm carrier while non-adsorbing carrier reactors showed sharp deterioration within 30 days due to contamination of non-atrazine degrading bacteria.

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