scholarly journals Kinetic study of CO2 reaction with CaO by a modified random pore model

2016 ◽  
Vol 18 (1) ◽  
pp. 93-98 ◽  
Author(s):  
S.M.M. Nouri ◽  
H. Ale Ebrahim
Keyword(s):  
Mercury Porosimetry ◽  
Nitrogen Adsorption ◽  
Intrinsic Rate ◽  
Product Layer ◽  
Carbonation Reaction ◽  
Pore Model ◽  
Partial Pressures ◽  
Pore Size Distributions ◽  
Kinetics Of ◽  
Random Pore Model

Abstract In this work, a modified random pore model was developed to study the kinetics of the carbonation reaction of CaO. Pore size distributions of the CaO pellets were measured by nitrogen adsorption and mercury porosimetry methods. The experiments were carried out in a thermogravimeter at different isothermal temperatures and CO2 partial pressures. A fractional concentration dependency function showed the best accuracy for predicting the intrinsic rate of reaction. The activation energy was determined as 11 kcal/mole between 550–700°C. The effect of product layer formation was also taken into account by using the variable product layer diffusivity. Also, the model was successfully predicted the natural lime carbonation reaction data extracted from the literature.

scholarly journals A modified random pore model for carbonation reaction of calcium oxide with carbon dioxide

2015 ◽  
Vol 69 (2) ◽  
pp. 209-217 ◽  
Author(s):  
Seyed Nouri ◽  
Habib Ebrahim ◽  
Bahram Nejad
Keyword(s):  
Carbon Dioxide ◽  
Calcium Oxide ◽  
Product Layer ◽  
Carbonation Reaction ◽  
Pore Model ◽  
Time Profiles ◽  
Rate Functions ◽  
Conversion Time ◽  
Reaction Constants ◽  
Random Pore Model

In this work, the random pore model was modified for a general concentration dependency and also bulk flow effect, in order to predict the carbonation reaction of calcium oxide with carbon dioxide. This reaction is one of the main methods for carbon dioxide capture from industrial flue gases. Different kinetic rate concentration functions were tested with the various literature experimental data for finding the best reaction constants and rate functions. Moreover, an exponential function for the diffusion of carbon dioxide through the product layer was proposed from the whole experimental conversion-time profiles.

A Comprehensive Kinetic Study of the SO2 Removal Reaction by Pure CuO with the Random Pore Model

2016 ◽  
Vol 41 (4) ◽  
pp. 385-397 ◽  
Author(s):  
Reza Bahrami ◽  
Habib Ale Ebrahim ◽  
Rouein Halladj ◽  
Ali Afshar
Keyword(s):  
Experimental Investigation ◽  
Mathematical Modelling ◽  
Product Layer ◽  
Solid Reaction ◽  
Pore Model ◽  
Time Profiles ◽  
So2 Removal ◽  
Partial Pressures ◽  
Conversion Time ◽  
Random Pore Model

An experimental investigation of the SO2 removal reaction by pure CuO was performed by thermogravimetry. In addition, mathematical modelling of this non-catalytic gas-solid reaction was performed using the random pore model. Modelling predictions of CuO conversion-time profiles at various temperatures and SO2 partial pressures compared well with the experimental results. The inherent rate constants and the product layer diffusivities were estimated between 400 and 600 °C.

scholarly journals Morphological Characterization of Nanofibers: Methods and Application in Practice

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Jakub Širc ◽  
Radka Hobzová ◽  
Nina Kostina ◽  
Marcela Munzarová ◽  
Martina Juklíčková ◽  
...  
Keyword(s):  
Specific Surface ◽  
Mercury Porosimetry ◽  
Three Dimensional ◽  
Nitrogen Adsorption ◽  
Morphological Characterization ◽  
Biologically Active ◽  
Porous Scaffolds ◽  
Electrospinning Technique ◽  
Pore Size Distributions

Biomedical applications such as wound dressing for skin regeneration, stem cell transplantation, or drug delivery require special demands on the three-dimensional porous scaffolds. Besides the biocompatibility and mechanical properties, the morphology is the most important attribute of the scaffold. Specific surface area, volume, and size of the pores have considerable effect on cell adhesion, growth, and proliferation. In the case of incorporated biologically active substances, their release is also influenced by the internal structure of nanofibers. Although many scientific papers are focused on the preparation of nanofibers and evaluation of biological tests, the morphological characterization was described just briefly as service methods. The aim of this paper is to summarize the methods applicable for morphological characterization of nanofibers and supplement it by the results of our research. Needleless electrospinning technique was used to prepare nanofibers from polylactide, poly(ε-caprolactone), gelatin, and polyamide. Scanning electron microscopy was used to evaluate the fiber diameters and to reveal eventual artifacts in the nanofibrous structure. Nitrogen adsorption/desorption measurements were employed to measure the specific surface areas. Mercury porosimetry was used to determine total porosities and compare pore size distributions of the prepared samples.

scholarly journals A Modified Random Pore Model for the Kinetics of Char Gasification

BioResources ◽  
2014 ◽  
Vol 9 (2) ◽  
Author(s):  
Jian-Liang Zhang ◽  
Guang-Wei Wang ◽  
Jiu-Gang Shao ◽  
Hai-Bin Zuo
Keyword(s):  
Pore Model ◽  
Char Gasification ◽  
Kinetics Of ◽  
Random Pore Model

scholarly journals Kinetics of stibnite (Sb2S3) oxidation at roasting temperatures

2014 ◽  
Vol 50 (2) ◽  
pp. 127-132 ◽  
Author(s):  
R. Padilla ◽  
A. Aracena ◽  
M.C. Ruiz
Keyword(s):  
Partial Pressure ◽  
Intrinsic Rate ◽  
Analysis Method ◽  
Surface Chemical Reaction ◽  
Partial Pressures ◽  
Rate Of Reaction ◽  
Detectable Rate ◽  
Shrinking Core ◽  
One Step ◽  
Kinetics Of

Experimental work on the oxidation of stibnite (Sb2S3) was carried out at temperatures between 350 and 500?C and oxygen partial pressures between 1.01 and 21.28 kPa by using a thermogravimetric analysis method. The oxidation rate of stibnite was significantly influenced by both temperature and partial pressure of oxygen. Stibnite oxidized in one step to valentinite (Sb2O3) and neither stibnite nor valentinite showed a detectable rate of volatilization at these low temperatures. The oxidation reaction of stibnite was analyzed by using the shrinking core model and it was found that the rate of reaction was controlled by the surface chemical reaction and it was of 3/5 order with respect to the oxygen partial pressure. The intrinsic rate constants were determined and an activation energy value of 90.3 kJ/mol was obtained for the range of temperature studied.

Unification of Gasification Kinetics of Char in CO2at Elevated Temperatures with a Modified Random Pore Model

2003 ◽  
Vol 17 (4) ◽  
pp. 961-970 ◽  
Author(s):  
Hao Liu ◽  
Chunhua Luo ◽  
Masahiro Kaneko ◽  
Shigeru Kato ◽  
Toshinori Kojima
Keyword(s):  
Elevated Temperatures ◽  
Pore Model ◽  
Kinetics Of ◽  
Random Pore Model

MERCURY POROSIMETRY HYSTERESIS AND ENTRAPMENT PREDICTIONS BASED ON A CORRUGATED RANDOM PORE MODEL

1991 ◽  
Vol 110 (1) ◽  
pp. 1-29 ◽  
Author(s):  
ATHENA TSETSEKOU ◽  
GEORGE ANDROUTSOPOULOS ◽  
REGINALD MANN
Keyword(s):  
Mercury Porosimetry ◽  
Pore Model ◽  
Random Pore Model

Study on Kinetics of Straw Stalk Gasification in CO2 with Random Pore Model

2014 ◽  
Vol 618 ◽  
pp. 316-320
Author(s):  
Hua Fei ◽  
Jin Ming Shi ◽  
Yuan Lin Li ◽  
Kai Luo
Keyword(s):  
Experimental Data ◽  
Reaction Model ◽  
Carbon Conversion ◽  
Pore Model ◽  
Different Temperatures ◽  
Shrinking Core ◽  
The Relationship ◽  
Kinetics Of ◽  
Core Reaction ◽  
Random Pore Model

The gasification of straw stalk in CO2 environment was studied by isothermal thermogravimetric analysis. The characteristics of rice straw and maize stalk gasification at different temperatures were examined under CO2 atmosphere. The relationship between reaction time and carbon conversion of two biomass chars was analyzed by the random pore model (RPM), and compared with the simulation of the shrinking core reaction model (SCRM). The results show that the random pore model is better to predict the experimental data at different temperatures. This means that the characteristics of pore structure for the influence of biomass chars gasification is well reflected by parameter ψ used in RPM. It indicates that the RPM can be applied to the comprehensive simulation of biomass chars gasification in CO2 environment.

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