scholarly journals Tailored activated carbons for supercapacitors derived from hydrothermally carbonized sugars by chemical activation

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 110629-110641 ◽  
Author(s):  
Kian Keat Lee ◽  
Wenming Hao ◽  
Mikaela Gustafsson ◽  
Cheuk-Wai Tai ◽  
Daniel Morin ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties

“Sugar”-supercapacitors: analyses of textural properties revealed that the specific capacitances for glucose derived-activated carbons correlated most strongly with ultramicropores.

scholarly journals Pinecone-Derived Activated Carbons as an Effective Medium for Hydrogen Storage

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2237
Author(s):  
Sara Stelitano ◽  
Giuseppe Conte ◽  
Alfonso Policicchio ◽  
Alfredo Aloise ◽  
Giovanni Desiderio ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Hydrogen Storage ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Hydrogen Adsorption ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Biomass Waste ◽  
Wavelength Dispersive Spectrometry

Pinecones, a common biomass waste, has an interesting composition in terms of cellulose and lignine content that makes them excellent precursors in various activated carbon production processes. The synthesized, nanostructured, activated carbon materials show textural properties, a high specific surface area, and a large volume of micropores, which are all features that make them suitable for various applications ranging from the purification of water to energy storage. Amongst them, a very interesting application is hydrogen storage. For this purpose, activated carbon from pinecones were prepared using chemical activation with different KOH/precursor ratios, and their hydrogen adsorption capacity was evaluated at liquid nitrogen temperatures (77 K) at pressures of up to 80 bar using a Sievert’s type volumetric apparatus. Regarding the comprehensive characterization of the samples’ textural properties, the measurement of the surface area was carried out using the Brunauer–Emmett–Teller method, the chemical composition was investigated using wavelength-dispersive spectrometry, and the topography and long-range order was estimated using scanning electron microscopy and X-ray diffraction, respectively. The hydrogen adsorption properties of the activated carbon samples were measured and then fitted using the Langmuir/ Töth isotherm model to estimate the adsorption capacity at higher pressures. The results showed that chemical activation induced the formation of an optimal pore size distribution for hydrogen adsorption centered at about 0.5 nm and the proportion of micropore volume was higher than 50%, which resulted in an adsorption capacity of 5.5 wt% at 77 K and 80 bar; this was an increase of as much as 150% relative to the one predicted by the Chahine rule.

scholarly journals CO2 and CH4 Adsorption Behavior of Biomass-Based Activated Carbons

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3136 ◽  
Author(s):  
Deneb Peredo-Mancilla ◽  
Imen Ghouma ◽  
Cecile Hort ◽  
Camelia Matei Ghimbeu ◽  
Mejdi Jeguirim ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Gas Adsorption ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Micropore Volume ◽  
Activation Method ◽  
Physical Activation

The aim of the present work is to study the effect of different activation methods for the production of a biomass-based activated carbon on the CO 2 and CH 4 adsorption. The influence of the activation method on the adsorption uptake was studied using three activated carbons obtained by different activation methods (H 3 PO 4 chemical activation and H 2 O and CO 2 physical activation) of olive stones. Methane and carbon dioxide pure gas adsorption experiments were carried out at two working temperatures (303.15 and 323.15 K). The influence of the activation method on the adsorption uptake was studied in terms of both textural properties and surface chemistry. For the three adsorbents, the CO 2 adsorption was more important than that of CH 4 . The chemically-activated carbon presented a higher specific surface area and micropore volume, which led to a higher adsorption capacity of both CO 2 and CH 4 . For methane adsorption, the presence of mesopores facilitated the diffusion of the gas molecules into the micropores. In the case of carbon dioxide adsorption, the presence of more oxygen groups on the water vapor-activated carbon enhanced its adsorption capacity.

Adsorption properties of cationic rhodamine B dye onto metals chloride-activated castor bean residue carbons

2016 ◽  
Vol 75 (4) ◽  
pp. 864-880 ◽  
Author(s):  
Lee Lin Zhi ◽  
Muhammad Abbas Ahmad Zaini
Keyword(s):  
Rhodamine B ◽  
Castor Bean ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Rate Limiting Step ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Enthalpy And Entropy ◽  
Rate Limiting

This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m2/g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.

scholarly journals Fitting Biochars and Activated Carbons from Residues of the Olive Oil Industry as Supports of Fe- Catalysts for the Heterogeneous Fenton-Like Treatment of Simulated Olive Mill Wastewater

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 876 ◽  
Author(s):  
Bruno M. Esteves ◽  
Sergio Morales-Torres ◽  
Francisco J. Maldonado-Hódar ◽  
Luis M. Madeira
Keyword(s):  
Olive Oil ◽  
Catalyst Deactivation ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Activation ◽  
Textural Properties ◽  
Oil Industry ◽  
Olive Mill Wastewater ◽  
Heterogeneous Fenton ◽  
Olive Mill

A series of biochars and activated carbons (ACs) was prepared combining carbonization and physical or chemical activation of cheap and abundant residues of the olive oil industry. These materials were used as Fe-support to develop low-cost catalysts for the heterogeneous Fenton-like oxidation of simulated olive mill wastewater (OMW), the highly pollutant effluent generated by this agroindustry. Commercial ACs were also used as reference. All catalysts prepared were extensively characterized and results related with their performances in the catalytic wet peroxide oxidation (CWPO). Results showed a linear relationship of the textural properties of the catalysts with the adsorptive and catalytic performance, as well as the preferential adsorption and degradation of some phenolic compounds (caffeic and gallic acids) by specific interactions with the catalysts’ surface. Despite the best performance of catalysts developed using commercial supports, those prepared from agro-industrial residues present some advantages, including a smaller catalyst deactivation by iron leaching. CWPO results show that catalysts from physically activated olive stones are the most promising materials, reaching total organic carbon and toxicity reductions of 35% and 60%, respectively, as well an efficient use of H2O2, comparable with those obtained using commercial supports. This approach showed that the optimized treatment of this type of residues will allow their integration in the circular economic process of the olive oil production.

scholarly journals Preparation of Pore-Size Controllable Activated Carbon from Rice Husk Using Dual Activating Agent and Its Application in Supercapacitor

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Khu Le Van ◽  
Thuy Luong Thi Thu
Keyword(s):  
Surface Area ◽  
Rice Husk ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Micropore Volume ◽  
Scan Rate ◽  
Activating Agent ◽  
Dual Activation ◽  
A Current

Activated carbons prepared from rice husk by chemical activation with dual activation agents, KOH and NaOH, have been studied and characterized by BET, SEM, EDX, FTIR, Boehm titration, Raman, and TGA. It was found that the KOH/NaOH impregnation ratio plays an important role on textural properties of AC. At the same amount of total alkali hydroxide, the KOH/NaOH ratio higher than 1.33 resulted in larger specific surface area (2990∼3043 m2·g−1), microporous surface area (2747∼2831 m2·g−1), and higher micropore volume (1.4250∼1.4316 cm3·g−1). The as-prepared samples exist in the form of spherical-shaped particles with the size ranging from 20 to 60 nm and contain numerous surface functional groups. The as-prepared activated carbons were then assessed as an electrode material of supercapacitor operating in the 0.5 M K2SO4 electrolyte in potential windows of −1.0∼0.0 V. The highest capacitance obtained was 205 F·g−1 at the scan rate of 2 mV·s−1 and 225 F·g−1 at a current density of 0.2 A·g−1. At the scan rate as high as 50 mV·s−1, all the as-prepared activated carbons in this study have the specific capacitance greater than 100 F·g−1.

scholarly journals CO2 and CH4 Adsorption Behavior of Biomass Based Activated Carbons

2018 ◽  
Author(s):  
Deneb Peredo-Mancilla ◽  
Imen Ghouma ◽  
Cecile Hort ◽  
Camelia Matei Ghimbeu ◽  
Mejdi Jeguirim ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Micropore Volume ◽  
Adsorption Behavior ◽  
Bet Surface Area ◽  
Ch4 Adsorption ◽  
Oxygen Groups ◽  
Physical And Chemical

The aim of the present study is to provide new insights into the CO2 and CH4 adsorption using a set of biomass-based activated carbons obtained by physical and chemical activation of olive-stones. The adsorption behavior is analyzed by means of pure gas adsorption isotherms up to 3.2 MPa at two temperatures (303.15 and 323.15 K).The influence of the activation method on the adsorption uptake is studied in terms of both textural properties and surface chemistry. For three activated carbons the CO2 adsorption was more important than that of CH4. The chemically activation resulted in higher BET surface area and micropore volume that lead to higher adsorption for both CO2 and CH4. For methane the presence of mesopores seems to facilitate the access of the gas molecules into the micropores while for carbon dioxide, the presence of oxygen groups enhanced the adsorption capacity.

Surface functionality and porosity of activated carbons obtained from chemical activation of wood

Carbon ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 669-674 ◽  
Author(s):  
H Benaddi ◽  
T.J Bandosz ◽  
J Jagiello ◽  
J.A Schwarz ◽  
J.N Rouzaud ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Chemical Activation ◽  
Surface Functionality

scholarly journals Computer Analysis of the Effect of Activation Temperature on the Microporous Structure Development of Activated Carbon Derived from Common Polypody

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz
Keyword(s):  
Activated Carbon ◽  
Porous Structure ◽  
Computer Analysis ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Geometrical Parameters ◽  
Activation Process ◽  
Microporous Structure ◽  
Activation Temperature

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.

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

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.

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