Film-Pore Diffusion Control for the Batch Sorption of Cadmium Ions from Effluent onto Bone Char

This study presents experimental studies of charcoal gasification with CO2 at different heating rates (1, 5, 10, 20, and 50 K min−1). The kinetics of the reaction C + CO2 under pore-diffusion control is studied. We propose a new method for the proper determination of activation energy during the processing of thermogravimetric curves of porous carbon gasification under conditions of pore-diffusion resistance. The results of the inverse kinetic problem solution are compared with different hypotheses about the regime of the investigated heterogeneous reaction process (kinetic, diffusion, pore-diffusion). The change of reaction regimes from kinetic to diffusion is detected during charcoal gasification at different heating rates. At heating rates of 5–20 K min−1, the values of activation energy of carbon gasification reaction in the carbon dioxide atmosphere, obtained by the proposed method, closely match the data found in the previous studies. The use of diffusion models in the processing of thermogravimetric curves determines the conditions under which conventional kinetic models fail to provide adequate information about the temperature dependence of the heterogeneous reaction rate.

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Sorption kinetic analysis for the removal of cadmium ions from effluents using bone char

Water Research ◽

10.1016/s0043-1354(00)00306-7 ◽

2001 ◽

Vol 35 (3) ◽

pp. 605-612 ◽

Cited By ~ 405

Author(s):

C.W Cheung ◽

J.F Porter ◽

G Mckay

Keyword(s):

Kinetic Analysis ◽

Bone Char ◽

Sorption Kinetic ◽

Cadmium Ions

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Modeling of gas-carbon reaction in pore diffusion control regime

Korean Journal of Chemical Engineering ◽

10.1007/bf02697474 ◽

1988 ◽

Vol 5 (1) ◽

pp. 35-40

Author(s):

Kyun Young Park ◽

Chongyoup Kim ◽

Won-Hoon Park

Keyword(s):

Pore Diffusion ◽

Diffusion Control ◽

Control Regime

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Nonlinear Frequency Response Analysis as a Tool for Identification of Adsorption Kinetics: Case Study—Pore-Surface Diffusion Control

Mathematical Problems in Engineering ◽

10.1155/2019/7932967 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Danica V. Brzić ◽

Menka T. Petkovska

Keyword(s):

Frequency Response ◽

Surface Diffusion ◽

Diffusion Coefficients ◽

Pore Diffusion ◽

Diffusion Control ◽

Response Analysis ◽

Nonlinear Frequency ◽

Pore Surface ◽

Kinetics Of Adsorption ◽

Nonlinear Frequency Response

In the present paper, the Nonlinear Frequency Response (NFR) analysis is applied for theoretical study of kinetics of adsorption governed by pore-surface diffusion. The concept of higher-order frequency response functions (FRFs) is used. Based on a nonlinear mathematical model for adsorption of pure gas and spherical adsorbent particles, the theoretical first- and second-order FRFs, which relate the adsorbate concentration in the particle to the surrounding pressure (F1(ω) and F2(ω,ω)), have been derived. The obtained FRFs have been simulated for different steady-state pressures and different ratios (between zero and one) of surface to pore diffusion coefficients. The results show that, unlike F1(ω), F2(ω,ω) exhibits features which unambiguously distinguish the pore-surface diffusion model from pure pore diffusion and micropore diffusion. Based on the characteristic features of F1(ω) and F2(ω,ω), a new methodology for direct estimation of the separate values of the pore and surface diffusion coefficients has been established.

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