scholarly journals Adsorption of CO2 on Activated Carbons Prepared by Chemical Activation with Cupric Nitrate

ACS Omega ◽  
2020 ◽  
Vol 5 (18) ◽  
pp. 10423-10432
Author(s):  
Sergio Acevedo ◽  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján
Author(s):  
Sergio Acevedo ◽  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján

Abstract Activated carbons are obtained by chemical activation of African Palm shells (Elaeis guineensis) with different impregnating agents, i. e. magnesium chloride (MgCl2) and calcium chloride (CaCl2) aqueous solutions at different concentrations (3, 5 and 7 % w/v) and temperatures (between 773 and 1073 K), in order to assess their influence on the development of the porosity. The activated carbons prepared are characterized in terms of both textural and chemical properties. The activated carbons have a surface area and a pore volume ranging between 19 and 501 m2.g−1 and 0.03–0.29 cm3.g−1, respectively. Based on the obtained results, the samples with higher surface area and pore volume (i. e. those impregnated with MgCl2 and CaCl2 solutions and thermally treated at 1073 K) are selected to evaluate the adsorption capacity and affinity for CO2. CO2 adsorption capacity varies between 1.78 and 2.95 mmolCO2.g−1 at 273 K and low pressure, and the activated carbon impregnated with the solution of MgCl2 3% and activated at 1073 K (i. e. ACMg3-1073) showed the best performances. Finally, the kinetic results show that adsorption rate for sample ACMg3-1073 is enhanced by its micro-mesoporous nature, being the access routes to the micropores larger.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7458
Author(s):  
Karolina Kiełbasa ◽  
Adrianna Kamińska ◽  
Oliwier Niedoba ◽  
Beata Michalkiewicz

Activated carbons with different textural characteristic were derived by the chemical activation of raw beet molasses with solid KOH, while the activation temperature was changed in the range 650 °C to 800 °C. The adsorption of CO2 on activated carbons was investigated. Langmuir, Freundlich, Sips, Toth, Unilan, Fritz-Schlunder, Radke-Prausnitz, Temkin-Pyzhev, Dubinin-Radushkevich, and Jovanovich equations were selected to fit the experimental data of CO2 adsorption. An error analysis (the sum of the squares of errors, the hybrid fractional error function, the average relative error, the Marquardt’s percent standard deviation, and the sum of the absolute errors) was conducted to examine the effect of using various error standards for the isotherm model parameter calculation. The best fit was observed to the Radke-Prausnitz model.


Author(s):  
Sergio Acevedo ◽  
Liliana Giraldo ◽  
Juan C. Moreno-Piraján

Abstract This article has been retracted due to honest error by the author. For further information, please see https://doi.org/10.1515/ijcre-2017-9198. Activated carbons are obtained by chemical activation of African Palm shells (Elaeis guineensis) with different impregnating agents, i. e. magnesium chloride (MgCl2) and calcium chloride (CaCl2) aqueous solutions at different concentrations (3, 5 and 7 % w/v) and temperatures (between 773 and 1073 K), in order to assess their influence on the development of the porosity. The activated carbons prepared are characterized in terms of both textural and chemical properties. The activated carbons have a surface area and a pore volume ranging between 19–501 m2.g−1 and 0.03–0.29 cm3.g−1, respectively. Based on the obtained results, the samples with higher surface area and pore volume (i. e. those impregnated with MgCl2 and CaCl2 solutions and thermally treated at 1073 K) are selected to evaluate the adsorption capacity and affinity for CO2. CO2 adsorption capacity varies between 1.78 and 2.95 mmolCO2.g−1 at 273 K and low pressure, and the activated carbon impregnated with the solution of MgCl2 3 % and activated at 1073 K (i. e. ACMg3-1073) showed the best performances. Finally, the kinetic results show that adsorption rate for sample ACMg3-1073 is enhanced by its micro-mesoporous nature, being the access routes to the micropores larger.


Author(s):  
Sergio Acevedo ◽  
Liliana Giraldo ◽  
Juan C. Moreno-Piraján

Abstract Retraction of https://doi.org/10.1515/ijcre-2017-0198.


Carbon ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 669-674 ◽  
Author(s):  
H Benaddi ◽  
T.J Bandosz ◽  
J Jagiello ◽  
J.A Schwarz ◽  
J.N Rouzaud ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4121
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek

In this study, the preparation of activated carbons from various materials of biomass origin by activation with potassium hydroxide and a comprehensive computer analysis of their porous structure and adsorption properties based on benzene (C6H6) adsorption isotherms were carried out. In particular, the influence of the mass ratio of the activator’s dry mass to the char mass on the formation of the microporous structure of the obtained activated carbons was analysed. The summary of the analyses carried out based on benzene adsorption isotherms begged the conclusion that activated carbon with a maximum adsorption volume in the first adsorbed layer and homogeneous surface can be obtained from ebony wood at a mass ratio of the activator to the char of R = 3. The obtained results confirmed the superiority of the new numerical-clustering-based adsorption analysis (LBET) method over simple methods of porous structure analysis, such as the Brunauer–Emmett–Teller (BET) and Dubinin–Raduskevich (DR) methods. The LBET method is particularly useful in the evaluation of the influence of the methods and conditions of production of activated carbons on the formation of their porous structure. This method, together with an appropriate economic analysis, can help in the precise selection of methods and conditions for the process of obtaining activated carbons at specific manufacturing costs, and thus makes it possible to obtain materials that can successfully compete with those of other technologies used in industrial practice and everyday life.


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