scholarly journals Properties of activated carbon regulated by rapid cooling treatment after pyrolysis

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 7935-7942
Author(s):  
Bing Wang ◽  
Huiyuan Chen ◽  
Yonggang Li ◽  
Hongyu Si ◽  
Haomin Wei ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Raw Materials ◽  
Average Pore Size ◽  
Process Conditions ◽  
Rapid Cooling

Effects of rapid cooling following pyrolysis were studied relative to the properties of activated carbon using different biomass as the raw materials. Coconut shell-based activated carbon (CSAC), bamboo-based activated carbon (BAC), and straw-based activated carbon (WSAC) were activated via high temperature and subsequently rapidly cooled to below minus 150 °C. The results showed that rapid cooling effectively increased the specific surface area, pore volume, and yield of activated carbons. Compared to natural cooling, rapid cooling increased the specific surface area of CSAC from 1076 m2/g to 1484 m2/g, increased the pore volume from 1.46 mL/g to 1.57 mL/g, decreased the average pore size from 2.25 nm to 2.13 nm, and increased the yield from 27.1% to 31.5%. The variation of the properties of activated carbon after rapid cooling using different raw materials and process conditions were studied using orthogonal experiments.

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.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

scholarly journals Activated Carbons from Thermoplastic Precursors and Their Energy Storage Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 896 ◽  
Author(s):  
Hye-Min Lee ◽  
Kwan-Woo Kim ◽  
Young-Kwon Park ◽  
Kay-Hyeok An ◽  
Soo-Jin Park ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Field Emission ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Cross Linking ◽  
Mesopore Volume

In this study, low-density polyethylene (LDPE)-derived activated carbons (PE-AC) were prepared as electrode materials for an electric double-layer capacitor (EDLC) by techniques of cross-linking, carbonization, and subsequent activation under various conditions. The surface morphologies and structural characteristics of the PE-AC were observed by field-emission scanning electron microscope, Cs-corrected field-emission transmission electron microscope, and X-ray diffraction analysis, respectively. The nitrogen adsorption isotherm-desorption characteristics were confirmed by Brunauer–Emmett–Teller, nonlocal density functional theory, and Barrett–Joyner–Halenda equations at 77 K. The results showed that the specific surface area and total pore volume of the activated samples increased with increasing the activation time. The specific surface area, the total pore volume, and mesopore volume of the PE-AC were found to be increased finally to 1600 m2/g, 0.86 cm3/g, and 0.3 cm3/g, respectively. The PE-AC also exhibited a high mesopore volume ratio of 35%. This mesopore-rich characteristic of the activated carbon from the LDPE is considered to be originated from the cross-linking density and crystallinity of precursor polymer. The high specific surface area and mesopore volume of the PE-AC led to their excellent performance as EDLC electrodes, including a specific capacitance of 112 F/g.

Preparation of Activated Carbons from Lignite for Electrochemical Capacitors by Microwave and Electrical Furnace Heating

2011 ◽  
Vol 194-196 ◽  
pp. 2472-2479 ◽  
Author(s):  
Bao Lin Xing ◽  
Chuan Xiang Zhang ◽  
Lun Jian Chen ◽  
Guang Xu Huang
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Electrochemical Capacitors ◽  
Weight Ratio ◽  
Total Pore Volume ◽  
Electrochemical Performances

Activated carbons (ACs) were prepared from lignite by microwave (MW) and electrical furnace (EF) heating with KOH as activation agent. In order to compare pore structures and electrochemical performances of ACs prepared by both heating methods, the ACs were characterized by N2 adsorption at 77K, X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical performances of Electrochemical capacitors (ECs) with ACs as electrodes in 3mol/L KOH electrolyte were evaluated by constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the pore structures of ACs prepared by MW and EF heating significantly enhance when the weight ratio of KOH to coal increases from 2 to 4. The BET specific surface area, total pore volume, the ratio of mesopore and average pore diameter of ACs prepared by MW heating (denoted as AC-MW4) reaches 2094m2/g, 1.193cm3/g, 53.6%, 2.28nm when the weight ratio of KOH to coal is 4, and ACs prepared by EF heating (denoted as AC-EF4) reaches 2580m2/g, 1.683cm3/g, 67.3%, 2.61nm. The ECs with AC-MW4 and AC-EF4 as electrodes present a high specific capacitance of 348F/g and 377F/g at a current density of 50mA/g, and still remain 325F/g and 350F/g after 500 cycles, respectively. Although the specific surface area, total pore volume and specific capacitance of ACs prepared by MW heating are slightly lower than EF heating, taking into account the heating time in the activation process, ACs prepared by EF heating needs approximate 140min, while MW heating only needs 10min, which have demonstrated that microwave heating technology is a promising and efficient technique to prepare ACs.

scholarly journals The Enhanced and Tunable Sustained Release of Pesticides Using Activated Carbon as a Carrier

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4019 ◽  
Author(s):  
Jun Yang ◽  
Wanyu Zang ◽  
Zheng Zhang ◽  
Peng Wang ◽  
Qing Yang
Keyword(s):  
Activated Carbon ◽  
Drug Release ◽  
Sustained Release ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Drug Loading ◽  
Utilization Efficiency ◽  
Physical Analysis

The sustained release of pesticides improves drug utilization efficiency and reduces their adverse effects. Activated carbon (AC) is an excellent adsorbent and promising soil conditioner. It has a rich, porous structure and thus can store and gradually release drugs. In this study, three AC materials with surface areas ranging from 800–2000 m2/g were used and two types of modified activated carbons were prepared, and their capacity as drug carriers was evaluated by using 2,4-Dichlorophenoxyacetic acid sodium (2,4-D sodium) as the model pesticide. The preparations were characterized by scanning electron microscopy, nitrogen physical analysis, and zeta potential. The five preparations showed an enhanced and tunable sustained release of drugs. AC1, with the highest specific surface area, possesses the best drug-loading capacity, reaching 679.18 mg/g, but the lowest drug release rate of 32.31% in 96 h. PDA-AC3 has the lowest specific surface area, showing limited drug-loading ability, 82.94 mg/g, but 100% drug release within 72 h. This study suggests that activated carbon has potent applications in agricultural pest control as an inexpensive, effective, controllable, and safe pesticide carrier.

RSM Optimization for the Production of Activated Carbons from Para-Wood Residue

2016 ◽  
Vol 718 ◽  
pp. 100-104 ◽  
Author(s):  
Pichaya Nitnithiphrut ◽  
Rangsinee Pimsri ◽  
Varinrumpai Seithtanabutara
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Operating Conditions ◽  
Optimal Conditions ◽  
Wood Residue ◽  
Impregnation Ratio ◽  
Rsm Optimization

Para-wood residue was impregnated in 40% wt. of H3PO4 solution for 24 h before carbonization under different temperatures and times. The response surface methodology (RSM) based on Box-Behnken was applied to optimize the operating conditions in producing activated carbon with high specific surface area. The effects of three variables; impregnation ratio, carbonising temperature and time on the specific surface of activated carbons were investigated. The proposed model was almost in accordance with the experimental case with correlation efficient and of 0.9653 and 0.9029, respectively. The optimal conditions were found to be 6%wt. of impregnation ratio and carbonization at 400°C for 67.27 min. The predicted surface area of produced activated carbon under these optimal conditions determined by RSM was 1069.30 m2/g. Experimental validation at these conditions was observed of 978.95 m2/g which closely agreed with the predicted value. This obtained activated carbon structure composed of mesopores and micropores with the average pore diameter of 21.71°A. This study indicated the RSM based on Box-Behnken design was the effectively method to optimize the operating condition and maximize the specific surface area of produced activated carbons.

Optimization of Experimental Conditions for the Preparation of High Specific Surface Area Bamboo-Based Activated Carbon

2015 ◽  
Vol 1090 ◽  
pp. 154-159
Author(s):  
Sheng Zhou Zhang ◽  
Hong Ying Xia ◽  
Li Bo Zhang ◽  
Jin Hui Peng ◽  
Jian Wu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Total Pore Volume ◽  
High Specific Surface Area ◽  
Raw Material ◽  
Experimental Conditions ◽  
Average Pore

Bamboo as the raw material is carbonized to prepare high specific surface area activated carbon by microwave heating under nitrogen atmosphere in our present work. Influences of activation agents on the preparation of activated carbon are studied. The results show that activation agents have a significant influence on the preparation of activated carbon. Under the heating time of 15 min, the adsorption capacity of the activated carbon prepared utilizing KOH as activation agent is the best. When the KOH/C ratio is 4, the iodine number and yield of activated carbon are 2298 mg/g and 39.82%, respectively. The BET specific surface area, total pore volume and average pore diameter of activated carbon are 3441 m2/g, 2.093 ml/g and 2.434 nm, respectively. The micropore volume of 1.304 ml/g is 62.30% of total pore volume, indicating that the activated carbon is microporous activated carbon.

scholarly journals INFLUENCE OF SYNTHESIS TECHNO-CHEMICAL PARAMETERS ON PHYSICOCHEMICAL CHARACTERISTICS OF BIOMIMETIC CALCIUM-PHOSPHATE NANOCOMPOSITE DOPED BY SILICATE AND CARBONATE ANIONS

2020 ◽  
Vol 5 (10) ◽  
pp. 47-56
Author(s):  
M. Troubitsin ◽  
Viet Hung Hoang ◽  
L. Furda
Keyword(s):  
Calcium Phosphate ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Average Pore Size ◽  
Average Crystallite Size ◽  
Average Pore ◽  
The Impact

The object of our investigation is a biomimetic calcium-phosphate nanocomposite doped by silicate and carbonate anions (BMHAP) synthesized by chemical deposition from aqueous solutions. The obtained samples are investigated using X-ray phase analysis (XRD), FTIR spectroscopy, and low-temperature nitrogen adsorption (BET method). The influence of the techno chemical synthesis parameters on the products characteristics (including phase composition, crystal lattice parameters, average crystallite size, specific surface area) is evaluated. The study on the effect of the synthesis temperature shows that with increasing in temperature from 22°C to 80°C, reveals a slight increase in the parameters of unit cells a and c, which leads to an increase in its volume. There is also a tendency towards a decrease in the average size of coherent scattering regions of crystallites (from 7,52 to 4,65 nm) and specific surface area (from 192,51 to 74,72 m2/g), but the pore volume and average pore diameter of the synthesized powders increases. The effect of the aging time of the sediment in the mother liquor is studied from 0,5 to 24 hours. It is found that with an increase in the maturation time of the sediment, the percent crystallinity of the powders improves by 1,7 times, an increase in the specific surface area from 163,43 to 192,51 m2/g and a slight decrease in the pore volume and average pore size of the samples are observed. The impact of the stirring rate of the reagents is investigated. An increase in speed from 300 to 1300 rpm has been shown to decrease the average crystallite size from 8,80 to 6,41 nm, and as a result, to increase the specific surface area of the synthesized samples from 178,58 to 192,51 m2/g, respectively.

scholarly journals STUDY OF SORPTION OF Ni AND Cd IONS ON NEW CARBON SORBENTS FROM KAZAKHSTAN RAW MATERIALS

2021 ◽  
Vol 57 (2) ◽  
pp. 106-113
Author(s):  
A.Zh. Yerman ◽  
◽  
A.A. Atchabarovа ◽  
K.K. Kishibaev ◽  
◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Raw Materials ◽  
Hot Water ◽  
Static Mode ◽  
Cadmium Ions ◽  
Pine Sawdust ◽  
Plant Waste

This article presents the optimal results of new sorbents for the sorption separation of nickel and cadmium ions based on waste of plant raw materials of the Republic of Kazakhstan - pine sawdust. To obtain activated carbon, pine sawdust based on plant waste was subjected to thermal treatment by carbonization methods at a temperature of 600-800 ° C and hydrothermal 220-260 ° C. Further, to increase the specific surface area, the samples after heat treatment were activated with hot water vapor at a temperature of 800-850 ° C for 1 hour. As a result of steam-gas activation, combustion of unstructured carbon and an increase in pores on the surface of activated carbon occur. In addition, the main physicochemical characteristics, sorption properties of the obtained activated carbon (specific surface area, m2 /g, fraction of pore volume, cm3 /g, average pore size, nm, sorption capacity by the amount of iodine,%) are considered. Also, the obtained sorption materials were studied in the process of sorption of nickel and cadmium ions from model solutions in a static mode. The optimal parameters of the sorption process were determined, at which the highest degree of extraction of nickel and cadmium ions is achieved: pH, phase contact time, ratio of solid and liquid phases. The recovery rate of cadmium and nickel ions in the static regime was more than 95% for cadmium and nickel. Keywords: activated carbon, sorbent, sorption, plant waste, nickel ion, cadmium ion

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