scholarly journals A New Approach for Controlling Mesoporosity in Activated Carbon by the Consecutive Process of Air Oxidation, Thermal Destruction of Surface Functional Groups and Carbon Activation (the OTA Method)

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2758
Author(s):  
Panuwat Lawtae ◽  
Chaiyot Tangsathitkulchai
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Functional Groups ◽  
Thermal Destruction ◽  
Total Pore Volume ◽  
Activation Method ◽  
Air Oxidation ◽  
Mesopore Volume ◽  
Activation Time ◽  
Activation Temperature

A new and simple method, based entirely on a physical approach, was proposed to produce activated carbon from longan fruit seed with controlled mesoporosity. This method, referred to as the OTA, consisted of three consecutive steps of (1) air oxidation of initial microporous activated carbon of about 30% char burn-off to introduce oxygen surface functional groups, (2) the thermal destruction of the functional groups by heating the oxidized carbon in a nitrogen atmosphere at a high temperature to increase the surface reactivity due to increased surface defects by bond disruption, and (3) the final reactivation of the resulting carbon in carbon dioxide. The formation of mesopores was achieved through the enlargement of the original micropores after heat treatment via the CO2 gasification, and at the same time new micropores were also produced, resulting in a larger increase in the percentage of mesopore volume and the total specific surface area, in comparison with the production of activated carbon by the conventional two-step activation method using the same activation time and temperature. For the activation temperatures of 850 and 900 °C and the activation time of up to 240 min, it was found that the porous properties of activated carbon increased with the increase in activation time and temperature for both preparation methods. A maximum volume of mesopores of 0.474 cm3/g, which accounts for 44.1% of the total pore volume, and a maximum BET surface area of 1773 m2/g was achieved using three cycles of the OTA method at the activation temperature of 850 °C and 60 min activation time for each preparation cycle. The two-step activation method yielded activated carbon with a maximum mesopore volume of 0.270 cm3/g (33.0% of total pore volume) and surface area of 1499 m2/g when the activation temperature of 900 °C and a comparable activation time of 240 min were employed. Production of activated carbon by the OTA method is superior to the two-step activation method for better and more precise control of mesopore development.

scholarly journals Effect of Air Oxidation on Texture, Surface Properties and Dye Adsorption of Wood-Derived Porous Carbon Materials

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1675 ◽  
Author(s):  
Suhong Ren ◽  
Liping Deng ◽  
Bo Zhang ◽  
Yafang Lei ◽  
Haiqing Ren ◽  
...  
Keyword(s):  
Surface Area ◽  
Functional Groups ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Dye Adsorption ◽  
Carbon Surface ◽  
Air Oxidation ◽  
Activation Temperature ◽  
Porous Carbon Materials ◽  
Hierarchical Porous

Hierarchical porous carbon materials made from cork were fabricated using a facile and green method combined with air activation, without any templates and chemical agents. The influence of air activation on the texture and other surface characteristics of the carbon materials were evaluated by various characterization techniques. Results indicate that air oxidation can effectively improve the surface area and the hierarchical porous structure of carbon materials, as well as increase the number of oxygen-containing functional groups on the carbon surface. The specific surface area and the pore volume of the carbon material activated by air at 450 °C (C800-M450) can reach 580 m2/g and 0.379 cm3/g, respectively. These values are considerably higher than those for the non-activated material (C800, 376 m2/g, 0.201 cm3/g). The contents of the functional groups (C–O, C=O and O–H) increased with rising activation temperature. After air activation, the adsorption capacity of the carbon materials for methylene blue (MB) and methyl orange (MO) was increased from 7.7 and 6.4 mg/g for C800 to 312.5 and 97.1 mg/g for C800-M450, respectively. The excellent dye removal of the materials suggests that the porous carbon obtained from biomass can be potentially used for wastewater treatment.

A Highly Efficient Activated Carbon by Chemical Activation Method for Adsorption of Paraquat (Toxin)

2013 ◽  
Vol 773-774 ◽  
pp. 471-477
Author(s):  
Md Mokhlesur Rahman ◽  
Mohamed Awang ◽  
Mohosina Bintey Shajahan ◽  
Tariq Abdul Razak ◽  
Kamaruzzaman Yunus
Keyword(s):  
Activated Carbon ◽  
Chemical Activation ◽  
Total Pore Volume ◽  
Activation Method ◽  
Nacl Solution ◽  
Adsorption Ability ◽  
Activation Temperature ◽  
Highly Efficient ◽  
Surface Areas

The optimum condition for preparing a highly efficient activated carbon has been investigated in this work. The effects of different activation temperatures on the pore structure and surface morphology of highly efficient activated carbon (AC) derived from waste palm shell by chemical activation method using phosphoric acid as activating agent were studied. For activation, different activation temperatures in the range of 550 °C-650 °C were carried out. Activated carbon with well developed pore size were produced at activation temperature of 600 °C for 2 hours. At this temperature the Brunauer , Emmett and Teller (BET) surface areas are 1287 m2g-1, the total pore volume for adsorption and desorption are 0.742 cm3 g-1. Scanning Electron Microscope also confirmed the porosity of the highly efficient activated carbon. Finally it was tested in vitro to determine its adsorbing capacity for paraquat as a toxin. For optimum adsorption ability of activated carbon for paraquat, 0.9% NaCl solution is the most suitable solvent. The paraquat preferentially adsorbed onto the activated carbon in NaCl solution. The adsorption ability of the activated carbon (the amount adsorbed) for paraquat observed to be 99.9 mg g-1.

scholarly journals Process Optimization of High Surface Area Activated Carbon Prepared from Cucumis Melo by H3PO4 Activation for the Removal of Cationic and Anionic Dyes Using Full Factorial Design

2021 ◽  
Vol 11 (5) ◽  
pp. 12662-12679
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Surface Area ◽  
Cucumis Melo ◽  
Contact Time ◽  
Chemical Activation ◽  
Activation Time ◽  
Anionic Dyes ◽  
Activation Temperature ◽  
Full Factorial

In this study, Chemical activation was used to prepare a low-cost activated carbon (AC) from agricultural waste material: Cucumis melo. It was used as a green biosorbent for the removal of cationic and anionic dyes from aqueous solutions (Methylene blue (MB) and Acid orange 7 (AO7)).A full factorial 24 experimental design was used to optimize the preparation conditions. The factors and levels included are activation temperature (300 and 500ºC), activation time (1 and 3 h), H3PO4 concentration (1.5 and 2.5 mol/L), and contact time (60 and 90 min). The surface area of the activated carbons and high removal efficiency of MB and AO7 was chosen as a measure of the optimization. The activated carbon prepared at 500 °C, for 3 hours with an H3PO4 concentration of 2.5 mol/L and a contact time of 90 min, have the largest specific surface area (475 m2/g) and the percentage of discoloration of methylene blue (99.4%). Furthermore, the greater value of AO7 removal (94.20%) was obtained at 3h - activation time, 500°C - activation temperature, 1.5 mol/L - H3PO4 concentration with a 90 min contact time.

scholarly journals Antibacterial properties of AgNO3-activated carbon composite on Escherichia coli: inhibition action

2018 ◽  
Vol 6 (1) ◽  
pp. 46
Author(s):  
Nkwaju Yanou Rachel ◽  
Baçaoui Abdelaziz ◽  
Ndi Julius Nsami ◽  
Kouotou Daouda ◽  
Yaacoubi Abdelrani ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Total Pore Volume ◽  
Carbon Composite ◽  
Micropore Volume ◽  
Bet Surface Area ◽  
Activation Temperature ◽  
X Ray ◽  
Impregnation Time ◽  
Methylene Blue Number

AgNO3- activated carbon composite based palm kernel shell was prepared by hydrothermal carbonization. The concentration of AgNO3, activation temperature and impregnation time were investigated on five responses (iodine number, methylene blue number, BET surface area, micropore volume and total pore volume). The most influential parameters of the preparation process were optimized using the Doehlert optimal design. From the ANOVA, the following optimal conditions of preparation were retained: 0.068 mol/L, 210°C and 3.7 h for AgNO3 concentration, activation temperature and impregnation time respectively. The activated carbon (AC) and the composite (AC-AgNO3) were characterized using Fourier Transform infrared spectroscopy, X-Ray diffraction, Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy and measurements of the surface area. The XRD pattern and SEM-EDX clearly confirmed the presence of silver in the composite. The experimental parameters of AC- AgNO3 composite were as followed: 708.44 mg/g; 293.09 mg/g; 713.0 m2/g; 0.49 cm3/g and 0.76 cm3/g, for iodine number, methylene blue number, BET surface area, micropore volume and total pore volume of AC- AgNO3 respectively. The antibacterial test carried on Escherichia Coli showed that AC-AgNO3 composite has a high-improved antibacterial property of 99.99% fixation with a dosage of 1500 ppm for 5 hours of contact time.

Preparation and Characterization of Microporous Activated Carbon from Raw Petroleum Cokes

2015 ◽  
Vol 814 ◽  
pp. 286-291
Author(s):  
Bo Tao Wang
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Activation Time ◽  
Activation Temperature

Adopting the chemical activation method, the high specific surface area activated carbon (AC) was prepared by the solid mixing method using Daqing petroleum cokes as raw materials and KOH as activator. The influence of the ratio of KOH to carbon, activation temperature and activation time on the iodine and methylene blue adsorption properties of the AC were studied. The micro-graphitic structure of the AC was studied by X-ray diffraction (XRD). The BET specific surface area, BJH pore size distribution and pore volume of the AC were determined by N2 adsorption (at 77K). The experimental results show that the high specific surface area AC can be prepared with the ratio of KOH to carbon of 4, activation temperature of 800°C and activation time of 1h. The specific surface area was as high as 2142 m2/g with the iodine adsorption value of 288mg/g and methylene blue adsorption value of 1266mg/g. The XRD and BJH results also show that amorphous carbon was the dominating form, and the pore size distribution represents micropore structure.

Sea Mango Activated Carbon Preparation and Characterization for Dye Removal

2015 ◽  
Vol 1113 ◽  
pp. 422-427
Author(s):  
Sethupathi Sumathi ◽  
Wei Liang Chong ◽  
Mohamed J.K. Bashir ◽  
Choon Aun Ng ◽  
Kanthasamy Ramesh
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Surface Area ◽  
Dye Removal ◽  
Value Added ◽  
Bet Surface Area ◽  
Blue Dye ◽  
Physical Activation ◽  
Activation Time ◽  
Activation Temperature

The conversion of sea mango oil into non-edible feedstock for biodiesel will lead to the production of abundant sea mango biomass as waste. Thus in this study, the potential of converting sea mango fiber waste into a value added product was analyzed. Sea mango fiber was utilized to produce activated carbon and was tested on dye removal. The sea mango activated carbon (SMAC) was prepared using physical activation by carbon dioxide. The preparation was carried out by varying the activation temperature (600-900 °C), gas flow rate (50–300 ml/min) and activation time (1.0-2.5 h). The parameters are manipulated using Design of Experiment. The prepared activated carbon was tested on methylene blue dye. SMAC was characterized by SEM, FTIR and BET surface area. Results showed that activation temperature and time have significant effect on the characteristic of SMAC and removal of dye. The optimum conditions for preparing the SMAC having the highest dye removal were found to be activation temperature of 810 °C, 178 ml/min of carbon dioxide flow and 1.9 h of activation time. The results showed that the BET surface area and dye removal efficiency of the SMAC are 540 m2/g and 95.6 % respectively.

scholarly journals Effect of Mesopore Development on Butane Working Capacity of Biomass-Derived Activated Carbon for Automobile Canister

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 673
Author(s):  
Byeong-Hoon Lee ◽  
Hye-Min Lee ◽  
Dong Chul Chung ◽  
Byung-Joo Kim
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Volume Fraction ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Working Capacity ◽  
Activation Time

Kenaf-derived activated carbons (AKC) were prepared by H3PO4 activation for automobile canisters. The microstructural properties of AKC were observed using Raman spectra and X-ray diffraction. The textural properties were studied using N2/77 K adsorption isotherms. Butane working capacity was determined according to the ASTM D5228. From the results, the specific surface area and total pore volume of the AKC was determined to be 1260–1810 m2/g and 0.68–2.77 cm3/g, respectively. As the activation time increased, the butane activity and retentivity of the AKC increased, and were observed to be from 32.34 to 58.81% and from 3.55 to 10.12%, respectively. The mesopore ratio of activated carbon increased with increasing activation time and was observed up to 78% at 973 K. This indicates that butane activity and retentivity could be a function not only of the specific surface area or total pore volume, but also of the mesopore volume fraction in the range of 2.8–3.8 nm and 5.5-6.5 nm of adsorbents, respectively. The AKC exhibit enhanced butane working capacity compared to commercial activated carbon with the high performance of butane working capacity due to its pore structure having a high mesopore ratio.

scholarly journals Activated carbon production from peat using ZnCl2: Characterization and applications

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8078-8092
Author(s):  
Toni Varila ◽  
Davide Bergna ◽  
Riikka Lahti ◽  
Henrik Romar ◽  
Tao Hu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Total Pore Volume ◽  
Total Carbon ◽  
Activation Temperature ◽  
Total Carbon Content ◽  
Different Temperatures ◽  
High Degree

The process for producing activated carbon from peat was optimized. The peat was impregnated with different ratios of ZnCl2, and the impregnated biomass was activated at different temperatures. The specific surface area, pore size distribution, total carbon content, and yield of the activated carbon were investigated. The best results for the specific surface area and mesoporosity of the activated peat were obtained by using a high impregnation ratio (2) and high activation temperature (1073 K). Highly porous activated carbon was produced that had a specific surface area of approximately 1000 m2/g and total pore volume that was higher than 0.5 cm3/g for most samples. The activated carbon had a high degree of mesoporosity. The adsorptive properties of the activated carbon were determined with methylene blue and orange II dyes.

scholarly journals Preparation and characterization of bio-based activated carbon from fish scales

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 614-621
Author(s):  
Qingsong Ji ◽  
Haichao Li ◽  
Jingjing Zhang
Keyword(s):  
Activated Carbon ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Activated Carbons ◽  
Structural Characteristics ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Fish Scales ◽  
Average Pore ◽  
Activation Temperature

The object of this study was to prepare activated carbons containing nitrogenous functional groups by a chemical method from nitrogen-containing raw materials. Fish (Ctenopharyngodon idellus) scales were impregnated with phosphoric acid (H3PO4) and activated at varied temperatures. The adsorption ability, structural characteristics, surface chemistry, and morphology of the activated carbons were characterized by methylene blue and iodine values, nitrogen adsorption, the Boehm method, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The total alkaline groups content of the activated carbon produced from fish scales was 0.4330 mmol/g, the total acidic groups was 1.68 mmol/g, the Brunauer–Emmett–Teller (BET) surface area was 501 cm2/g, and the total pore volume was 0.284 cm3/g. The average pore diameter was 1.94 nm under an activation temperature of 550 °C, an activation time of 1 h, and an impregnation ratio of 2. As a result of this study, nitrogenous functional groups that contained acid-base amphoteric adsorbent were produced.

scholarly journals Superheated water pretreatment combined with CO2 activation/regeneration of the exhausted activated carbon used in the treatment of industrial wastewater

2017 ◽  
Vol 76 (7) ◽  
pp. 1687-1696 ◽  
Author(s):  
Jin Xiao ◽  
Bailie Yu ◽  
Qifan Zhong ◽  
Jie Yuan ◽  
Zhen Yao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Co2 Activation ◽  
Superheated Water ◽  
Adsorption Model ◽  
Experimental Conditions ◽  
Activation Temperature ◽  
Water Pretreatment

This paper examines a novel method of regenerating saturated activated carbon after adsorption of complex phenolic, polycyclic aromatic hydrocarbons with low energy consumption by using superheated water pretreatment combined with CO2 activation. The effects of the temperature of the superheated water, liquid–solid ratio, soaking time, activation temperature, activation time, and CO2 flow rate of regeneration and adsorption of coal-powdered activated carbon (CPAC) were studied. The results show that the adsorption capacity of iodine values on CPAC recovers to 102.25% of the fresh activated carbon, and the recovery rate is 79.8% under optimal experimental conditions. The adsorption model and adsorption kinetics of methylene blue on regenerated activated carbon (RAC) showed that the adsorption process was in accordance with the Langmuir model and the pseudo-second-order kinetics model. Furthermore, the internal diffusion process was the main controlling step. The surface properties, Brunauer–Emmett–Teller (BET) surface area, and pore size distribution were characterized by Fourier transform infrared spectroscopy (FT-IR) and BET, which show that the RAC possesses more oxygen-containing functional groups with a specific surface area of 763.39 m2 g−1 and a total pore volume of 0.3039 cm3 g−1. Micropores account for 79.8% and mesopores account for 20.2%.

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