scholarly journals Review on Activated Carbons by Chemical Activation with FeCl3

2020 ◽  
Vol 6 (2) ◽  
pp. 21 ◽  
Author(s):  
Jorge Bedia ◽  
Manuel Peñas-Garzón ◽  
Almudena Gómez-Avilés ◽  
Juan J. Rodriguez ◽  
Carolina Belver
Keyword(s):  
Activated Carbons ◽  
Surface Acidity ◽  
Chemical Activation ◽  
Activation Mechanism ◽  
Carbon Precursor ◽  
Iron Species ◽  
Activation Temperature ◽  
Synthesis Conditions ◽  
Porous Texture ◽  
Graphitization Degree

This study reviews the most relevant results on the synthesis, characterization, and applications of activated carbons obtained by novel chemical activation with FeCl3. The text includes a description of the activation mechanism, which compromises three different stages: (1) intense de-polymerization of the carbon precursor (up to 300 °C), (2) devolatilization and formation of the inner porosity (between 300 and 700 °C), and (3) dehydrogenation of the fixed carbon structure (>700 °C). Among the different synthesis conditions, the activation temperature, and, to a lesser extent, the impregnation ratio (i.e., mass ratio of FeCl3 to carbon precursor), are the most relevant parameters controlling the final properties of the resulting activated carbons. The characteristics of the carbons in terms of porosity, surface chemistry, and magnetic properties are analyzed in detail. These carbons showed a well-developed porous texture mainly in the micropore size range, an acidic surface with an abundance of oxygen surface groups, and a superparamagnetic character due to the presence of well-distributed iron species. These properties convert these carbons into promising candidates for different applications. They are widely analyzed as adsorbents in aqueous phase applications due to their porosity, surface acidity, and ease of separation. The presence of stable and well-distributed iron species on the carbons’ surface makes them promising catalysts for different applications. Finally, the presence of iron compounds has been shown to improve the graphitization degree and conductivity of the carbons; these are consequently being analyzed in energy storage applications.

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.

Wood-based activated carbons for supercapacitors with organic electrolyte

Holzforschung ◽  
2015 ◽  
Vol 69 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Galina Dobele ◽  
Aleksandrs Volperts ◽  
Galina Telysheva ◽  
Aivars Zhurinsh ◽  
Daria Vervikishko ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Specific Capacity ◽  
Total Pore Volume ◽  
Synthesis Temperature ◽  
Raw Material ◽  
Organic Electrolyte ◽  
Electrochemical Characteristics ◽  
Activation Temperature ◽  
Synthesis Conditions ◽  
Ohmic Losses

Abstract The thermocatalytical synthesis conditions required for the activation of wood charcoal with NaOH in terms of the formation of pores in its structure were investigated. The present study was conducted to explore the potential application of activated carbons as electrodes in supercapacitors with organic electrolyte. The total pore volume and micro- and mesopore ratio were controlled by the activation temperature and alkali addition rate. The working characteristics of carbon electrodes (e.g., specific capacity and ohmic losses) in supercapacitors are strongly influenced by the properties of the pores in their structures. Herein, the optimal ratio of raw material to activator and activation temperature are established: an increase in the ratio of NaOH to carbonizate rate by a factor of 2 and setting the synthesis temperature at 700°C positively influence the electrochemical characteristics of supercapacitors and provide them with specific capacities of up to 160 F g-1.

Preparation of activated carbons from wet activated sludge by direct chemical activation

2009 ◽  
Vol 59 (12) ◽  
pp. 2387-2394 ◽  
Author(s):  
X. Wang ◽  
N. Zhu ◽  
J. Xu ◽  
B. Yin
Keyword(s):  
Activated Carbon ◽  
Activated Sludge ◽  
Water Content ◽  
Iodine Value ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Total Pore Volume ◽  
Processing Parameters ◽  
Experimental Conditions ◽  
Activation Temperature

An improved method for preparing activated carbons from wet waste activated sludge (WAS) by direct chemical activation was studied in this paper. The effects of processing parameters on iodine adsorption capacity of the product were investigated. Results show that sludge-based activated carbon prepared with KOH had a larger iodine value than those activated with ZnCl2 and KCl. The maximum iodine value was observed at the KOH concentration of 0.50 M. Increasing the impregnation time from 10 to 20 h resulted in a 20% increase in the iodine value. The highest iodine value was obtained at the activation temperature of 600°C and holding time of 1 h. Sludge water content had insignificant effects on the iodine value of products. Raw WAS with a water content of 93.2% can be converted into an activated carbon with a high specific surface area of 737.6 m2 g−1 and iodine value of 864.8 mgg−1 under optimum experimental conditions. Other physical properties such as total pore volume, micropore volume and mean pore diameter of the product were also reported and compared with those of commercial activated carbon.

Fungi-derived hierarchically porous carbons for high-performance supercapacitors

RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4396-4403 ◽  
Author(s):  
Jiacheng Wang ◽  
Qian Liu
Keyword(s):  
High Performance ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Organic Electrolyte ◽  
Carbon Precursor ◽  
Porous Carbons ◽  
Hierarchically Porous ◽  
Renewable Biomass ◽  
Supercapacitor Performance

Chemical activation of sustainable, renewable biomass fungi as the carbon precursor resulted in hierarchically porous activated carbons, demonstrating superior supercapacitor performance in organic electrolyte to commercially available carbons.

Preparation and Characterization of Activated Carbon from Reedy Grass Leaves by Chemical Activation with KOH

2014 ◽  
Vol 881-883 ◽  
pp. 579-583 ◽  
Author(s):  
Ling Zhi Chen ◽  
Dong Xu Miao ◽  
Xiao Jie Feng ◽  
Jian Zhong Xu
Keyword(s):  
Iodine Number ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Weight Ratio ◽  
Raw Material ◽  
Bet Surface Area ◽  
Activation Temperature ◽  
Impregnation Ratio ◽  
Dta Analysis

Activated carbons (AC) were produced by chemical activation with potassium hydroxide (KOH) at 800°C from chars that were carbonized from reedy grass leaves at 450°C in N2atmosphere. The effects of the weight ratio of KOH/char ( impregnation ratio), activation temperature and duration time were examined. Adsorption capacity was demonstrated with iodine number. BET surface area, pore volume and pore size of activated carbons were characterized by N2adsorption isotherms. The maximum surface area and iodine number of the AC was 1100 m2/g and 1080 mg/g produced at 800°C for2h and impregnation ratio is 4:1.The characteristics of activated carbons were determined by Infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Thermal gravimetry (TG/DTA) analysis of raw material was carried out.

scholarly journals Activated Carbons (AC) Prepared by Direct CO2 Activation of Parsea Americana seeds Biomass for Supercapacitor Electrodes

2021 ◽  
Vol 2049 (1) ◽  
pp. 012067
Author(s):  
Rakhmawati Farma ◽  
Ramadani Putri Anakis ◽  
Irma Apriyani
Keyword(s):  
Activated Carbons ◽  
Chemical Activation ◽  
Physical Activation ◽  
Co2 Activation ◽  
X Ray Diffraction ◽  
Activation Temperature ◽  
X Ray ◽  
Cyclic Voltametry ◽  
Scanning Electron

Abstract Biomass converted into activated carbon (AC) by using physical activation method can form micro-meso pore structure and maintain the interconnected natural pore network of biomass. AC is prepared from the biomass of Parsea Americana seeds (PAS) through a process of pre-carbonization, chemical activation, carbonization and physical activation which is activated at temperatures of 700°C, 800°C, and 900°C. Characterization of physical properties of AC electrodes consisted of X-ray diffraction, Scanning Electron Microscope-Energy Dispersive X-ray and characterization of electrochemical properties of supercapacitor cells using Cyclic Voltametry. The results showed that the microstructure of the AC electrode has a semicrystalline structure characterized by the presence of two sloping peaks at an angle of 2θ around 24° and 44° which corresponded to the hkl (002) and (100) planes, where the lowest Lc value was produced by the PAS-900 sample. The PAS-900 sample had aggregates or lumps with smaller size in small amounts in the presence of micro-mesopores and had the highest carbon content of 94.50% with the highest capacitance value of 203.12 F/g. The temperature of 900°C is the best activation temperature in the process of manufacture AC electrodes from Parsea Americana seeds biomass for supercapacitor cell applications.

scholarly journals CO2 Adsorption on Activated Carbons Prepared from Molasses: A Comparison of Two and Three Parametric Models

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7458
Author(s):  
Karolina Kiełbasa ◽  
Adrianna Kamińska ◽  
Oliwier Niedoba ◽  
Beata Michalkiewicz
Keyword(s):  
Co2 Adsorption ◽  
Activated Carbons ◽  
Error Function ◽  
Chemical Activation ◽  
Parametric Models ◽  
Activation Temperature ◽  
Textural Characteristic ◽  
Fractional Error ◽  
Adsorption Of Co2 ◽  
Best Fit

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.

scholarly journals Effect of Activating Agent on the Properties of TiO2/Activated Carbon Heterostructures for Solar Photocatalytic Degradation of Acetaminophen

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 378 ◽  
Author(s):  
Manuel Peñas-Garzón ◽  
Almudena Gómez-Avilés ◽  
Jorge Bedia ◽  
Juan Rodriguez ◽  
Carolina Belver
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Anatase Phase ◽  
Chemical Activation ◽  
Reaction Medium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Texture ◽  
Adsorption Desorption ◽  
Synthesized Materials

Several activated carbons (ACs) were prepared by chemical activation of lignin with different activating agents (FeCl3, ZnCl2, H3PO4 and KOH) and used for synthesizing TiO2/activated carbon heterostructures. These heterostructures were obtained by the combination of the activated carbons with a titania precursor using a solvothermal treatment. The synthesized materials were fully characterized (Wavelength-dispersive X-ray fluorescence (WDXRF), X-ray diffraction (XRD), Scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier transform infrared (FTIR) and UV-visible diffuse reflectance spectra (UV-Vis DRS) and further used in the photodegradation of a target pharmaceutical compound (acetaminophen). All heterostructures were composed of anatase phase regardless of the activated carbon used, while the porous texture and surface chemistry depended on the chemical compound used to activate the lignin. Among all heterostructures studied, that obtained by FeCl3-activation yielded complete conversion of acetaminophen after 6 h of reaction under solar-simulated irradiation, also showing high conversion after successive cycles. Although the reaction rate was lower than the observed with bare TiO2, the heterostructure showed higher settling velocity, thus being considerably easier to recover from the reaction medium.

scholarly journals The interaction of metallic ions onto activated carbon surface using computational chemistry software

2020 ◽  
Vol 38 (5-6) ◽  
pp. 191-204
Author(s):  
AL Paredes-Doig ◽  
A Pinedo-Flores ◽  
J Aylas-Orejón ◽  
D Obregón-Valencia ◽  
MR Sun Kou
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Electron Density ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Chemical Activation ◽  
Carbon Surface ◽  
Maximum Adsorption Capacity ◽  
Metallic Ions ◽  
Oxidized Activated Carbon

Activated carbon was prepared from the seeds of aguaje palm ( Mauritia flexuosa L.f.) by a chemical activation with phosphoric acid. This activated carbon was used for adsorbing metal ions: Pb(II), Cd(II), and Cr(III). To understand the mechanism of adsorption of these heavy metals (Cr, Cd, and Pb), the activated carbon surface was oxidized with nitric acid (1 M) increasing the oxygenated surface groups showing an increasing in their adsorption capacities of these metals. The oxidized activated carbon slightly increased the maximum adsorption capacity to 5–7%. The order of adsorption for unoxidized and oxidized activated carbons was Pb> Cd> Cr. This experimental information was corroborated by molecular modeling program Hyperchem 8 based adsorption mainly on two factors: the electron density and orbitals—highest occupied molecular orbital and lowest unoccupied molecular orbital.Activated carbons were characterized by adsorption/desorption of N2, obtaining an increase of microporous surface area for oxidized activated carbon. An increase of surface acidity and a reduction of isoelectric points were observed in oxidized activated carbon. According to these results, the adsorption of metal ions is favored in contact with an oxidized activated carbon, which has more amount of phenolic and carboxylic functional groups. Similarly, decreasing the isoelectric point indicates that the surface has a higher negative charge. The surface information was corroborated by Hyperchem, which indicates that the surface of the oxidized activated carbon has a higher electron density, indicating a larger amount of electrons on its surface, which means the surface of oxidized activated carbon charges negatively and thereby attracts metal ions.

scholarly journals Effect of Activator Type on Activated Carbon Characters from Teak Wood and The Bleaching Test for Waste Cooking Oil

2020 ◽  
Vol 15 (2) ◽  
pp. 79-89
Author(s):  
Sriatun Sriatun ◽  
Shabrina Herawati ◽  
Icha Aisyah
Keyword(s):  
Activated Carbon ◽  
Iodine Number ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Waste Cooking Oil ◽  
Physical Activation ◽  
Activation Process ◽  
Activation Temperature ◽  
Cooking Oil

The starting material for activated carbon was biomass from teak woodcutting, which consists of 47.5% cellulose, 14.4% hemicellulose, and 29.9% lignin. The surface area and iodine number of activated carbons are the factors determining the adsorption ability. This study aims to determine the effect of the activator type on activated carbon characters and test the absorption ability for waste cooking oil. The synthesis stages include carbonization, chemical activation, and then physics activation. The activation process consists of two steps. Firstly, the chemical activation via adding H2SO4, and H3PO4 at room temperature for 24 hours, the second, physical activation by heating at various temperatures of 300, 400, and 500 °C for two hours. The characterizations of activated carbon include water content, ash content, iodine number, functional groups, and surface area. Furthermore, the activated carbon was used as an adsorbent for waste cooking oil for 60 minutes at 100 °C with a stirring of 500 rpm. The results were analyzed using UV-Vis spectrophotometry at a maximum wavelength of 403 nm. The iodine numbers of activated carbon ranged 481.1-1211.4 mg/g and 494.8-1204 mg/g for H3PO4 and H2SO4, respectively.Activated carbon with H3PO4 of 15% and an activation temperature of 400 °C has the highest surface area of 445.30 m2/g.  The H2SO4 dan H3PO4 activators can be used to improve the quality of activated carbon in absorbing dyes in waste cooking oil, where the optimum concentration is 10-15% (v/v). The H3PO4 activator tends to produce a higher bleaching percentage than H2SO4. 

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