scholarly journals Thermal analysis as a method for evaluating the quality of regeneration of activated carbon used for purification of glycerin

Surface ◽  
2020 ◽  
Vol 12(27) ◽  
pp. 137-145
Author(s):  
M. V. Borysenko ◽  
◽  
Ya. M. Chubenko ◽  
I. I. Voitko ◽  
T. S. Chorna ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Methylene Blue ◽  
Activated Carbon ◽  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Thermal Regeneration

In this work, we investigated granular and powder activated carbons (AC) – initial and waste with adsorbed impurities after purification of technical glycerin and subsequent washing with water. The aim of this work was to quantify the adsorbed impurities in the spent AC using thermal analysis (TA) and to work out the conditions for thermal regeneration of AC. TA of AC samples was carried out in an atmosphere of helium and air; the specific surface area of AC was measured by the method of low-temperature desorption of argon (SAr). It was established by the TA method that water is released in the temperature range of 20 – 170 °C, and glycerin – 170 – 400 °C. Spent AC contains up to 22.8 wt. % H2O and up to 44.6 wt. % C3H5(OH)3. Based on these data, it was proposed to regenerate spent coal by heating at 400 °C in air. In the case of a granular AC sample, the regeneration proceeds completely, while for a powder AC sample, the specific surface area with respect to argon is restored only by 22 %, from the initial 2170 m2/g. The adsorption isotherms of methylene blue (MB) of the initial samples are located higher than for the spent ones, since in the spent ones part of the surface is occupied by adsorbed glycerin. The SMB values calculated from the adsorption of methylene blue in the spent AC samples are strongly overestimated in comparison with SAr. Probably, MB displaces glycerin from the surface or interacts with it to form complexes.

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.

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.

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 Effect of Chemical Activating Agents on Surface Area and Methylene Blue Uptake Capacity of Activated Carbons

2021 ◽  
Vol 64 (3) ◽  
pp. 254-264
Author(s):  
Muhammad Saleem
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
Ph Value ◽  
Volatile Matter ◽  
Uptake Capacity ◽  
Production Parameters ◽  
Activating Agent

Activated carbon from Acacia asak (Fabaceae) tree branches was prepared utilizing three-steps- process and H3P04, ZnCl2, H2S04, K2C03, Na0H and K0H as chemical activating agents. In addition to the elemental analysis of precursor materials, produced activated carbon (ATB-AC) was also analyzed for moisture content, ash content, pH value, bulk density, volatile matter, hardness, specific surface area (SBET), iodine number and pore volume. Results revealed that the quality of ATB-AC is well comparable to the available commercial activated carbon (CAC). The SBET was found to be in the order of ATB-AC1> ATB- AC2> ATB-AC4> ATB-AC6> ATB-AC3> ATB-AC5. All the produced ATB-AC demonstrated good MB (methylene blue) removal efficiency, whereas ATB-AC1 and ATB-AC2 (produced from H3P04, and ZnCl2) showed higher efficiency. It is concluded that the chemical activating agent has significant effect on produced AC keeping all other production parameters constant. Among the six studied chemicals, H3P04 and ZnCl2 produced AC exhibited high SBET surface area and MB uptake capacity.  

scholarly journals Determination of the Adsorption Activity of the Specific Surface of Artificial Graphite by the Indicator of Methylene Blue

2020 ◽  
Vol 6 (4) ◽  
pp. 252-256
Author(s):  
N. Aldasheva
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Adsorption Activity ◽  
Indicator Solution ◽  
Artificial Graphite ◽  
Blue Solution

This article investigated and determined the specific surface area of artificial graphite for adsorption through a methylene blue solution. The study showed that the specific surface area of graphite adsorption obtained from coal from the Uzgen deposit in Kyrgyzstan for methylene blue is 599.4 m2/g and this is very close to the performance of activated carbons. The specific surface area of artificial graphite obtained from coal from the Uzgen deposit for adsorption activity was determined by titration of a suspension with a methylene blue indicator solution.

Adsorption of methylene blue dye onto activated carbons based on agricultural by-products: equilibrium and kinetic studies

2013 ◽  
Vol 67 (8) ◽  
pp. 1688-1694 ◽  
Author(s):  
Z. Ioannou ◽  
J. Simitzis
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Kinetic Studies ◽  
Blue Dye ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Mb Adsorption

Mixtures of novolac resin and olive stone biomass (20/80 and 40/60 w/w) were cured, pyrolyzed up to 1,000 °C and activated with CO2 under a continuous flow operation (named N20B-cCa and N40B-cCa respectively). Commercial activated charcoal was similarly re-activated with CO2 and used for comparison reasons (AC-a). The characterization of these materials was performed by Fourier transform Infrared (FTIR) analysis and their specific surface area was determined according to DIN 66132. The materials were tested for their adsorption abilities at different temperatures (298, 333 K) and initial dye concentrations (0.01–0.35 g/L) using 1 L of methylene blue (MB) solution in 10 g of activated carbon. MB adsorption kinetic was also studied. The FTIR spectra of all activated carbons show absorption peaks which correspond to –OH, –CH, –C–O–C– groups and to aromatic ring. The presence of the absorption peak at about 1,400 cm−1 for N20B-cCa, N40B-cCa indicates more acidic groups on them compared to the commercial AC-a. The specific surface area of N20B-cCa, N40B-cCa and AC-a has values equal to 352, 342 and 760 m2/g respectively. From the applied kinetic models, pseudo-second-order equation could best describe MB adsorption. Consequently, such adsorbents can be used as filters to adsorb dyes from wastewaters.

scholarly journals Characterization of Activated Carbon Fibers

1990 ◽  
Vol 209 ◽  
Author(s):  
A. W. P. Fung ◽  
A. M. Rao ◽  
K. Kuriyama ◽  
M. S. Dresselhaus ◽  
G. Dresseliiaus ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Disordered Systems ◽  
Activated Carbon Fibers ◽  
Characterization Of Activated Carbon

AbstractLow-temperature electrical conductivity and Raman scattering are studied as characterization tools for activated carbon fibers, which have a high density of defects and a huge specific surface area. The transport mechanism at low temperature is governed by variablerange hopping, as in other strongly disordered systems. From the Raman spectra obtained, we deduce that the long phenolic fibers are more disordered than the acrylic fibers and that increased specific surface area corresponds to increased disorder. The average in-plane microcrystallite size is about 20–30 Å.

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