Characterization of mass transfer in a shallow fluidized bed for adsorption processes: Modeling and supporting experiments

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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INVESTIGATION ON HYDRODYNAMICS OF FLUIDIZED BED AS A COMPONENT DETERMINING HEAT AND MASS TRANSFER

10.1615/ihtc5.900 ◽

1974 ◽

Cited By ~ 1

Author(s):

N. B. Kondukov ◽

L.I. Frenkel ◽

M. B. Kliot ◽

B. V. Pankov ◽

V. S. Potapochkin ◽

...

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Fluidized Bed

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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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Global characterization of hydrodynamics and gas-liquid mass transfer in a thin-gap bubble column intended for microalgae cultivation

Chemical Engineering and Processing - Process Intensification ◽

10.1016/j.cep.2017.10.009 ◽

2017 ◽

Vol 122 ◽

pp. 76-89 ◽

Cited By ~ 7

Author(s):

Charlène Thobie ◽

Emilie Gadoin ◽

Walid Blel ◽

Jérémy Pruvost ◽

Caroline Gentric

Keyword(s):

Mass Transfer ◽

Bubble Column ◽

Microalgae Cultivation ◽

Liquid Mass ◽

Liquid Mass Transfer

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Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

Scientific Reports ◽

10.1038/s41598-021-84797-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sivarama Krishna Lakkaboyana ◽

Khantong Soontarapa ◽

Nabel Kalel Asmel ◽

Vinay Kumar ◽

Ravi Kumar Marella ◽

...

Keyword(s):

Methylene Blue ◽

Kinetic Models ◽

Batch Reactor ◽

Maximum Adsorption Capacity ◽

Nano Composite ◽

Adsorption Processes ◽

Intra Particle Diffusion ◽

Short Time ◽

Efficient Adsorbent

AbstractThe present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)2-NWs-PVA-AC). The obtained Cu(OH)2-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution pH, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir–Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94–98.5% with a span of 10 min. and decent adsorption of about 98.5% at a pH of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (− 44.11 to − 48.86 kJ/mol) and a low negative value of ΔH° (− 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.

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