• Journal of Environmental Health Sciences
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• v.34 no.3
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• pp.240-246
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• 2008

The purpose of this study was to gain basic information on the characteristics of $CO_2$ adsorption in relation to $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon in a Fixed Bed Reactor. From the results of this study the following conclusions were made: $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon had a longer breakthrough time and more enhanced adsorption capacity than activated carbon alone. When tested with isothermal adsorption and tested for $CO_2$ adsorption the amount of $CO_2$ adsorbed varied with temperature, $CO_2$ inlet concentration, gas flow rate, aspect ratio, etc. Based on the results, when Langmuir, Freundlich and Dubinin-Polanyi adsorption isotherms were used for linear regression of isothermal adsorption data, Langmuir adsorption isotherm was the most suitable. And, the optimum condition for $Na_2CO_3$ and $K_2CO_3$ impregnated activated carbon make-up was 1N and $Li_2CO_3$ was 0.1N. It could be concluded that adsorption capacity was decreased with adsorption temperature and increased gas concentration. When the aspect ratio (L/D) was varied 0.5, 1.0 and 2.0, the significant drop of adsorption amount was observed below 1.0 and breakthrough time was shortened with gas flow rate.

• Carbon letters
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• v.25
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• pp.68-77
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• 2018

Soybean straw (SS)-based activated carbon was employed as a precursor to prepare carbon molecular sieves (CMSs) via chemical vapor deposition (CVD) technique using methane as carbon source. Prior to the CVD process, SS was activated by 0.5 wt% $ZnCl_2$, followed by a carbonization at $500^{\circ}C$ for 1 h in $N_2$ atmosphere. $N_2$ (77 K) adsorption-desorption and $CO_2$ (273 K) adsorption tests were carried out to analyze the pore structure of the prepared CMSs. The results show that increasing the deposition temperature, time or methane flow rate leads the decrease in $N_2$ adsorption capacity, micropore volume and average pore diameter of CMSs. The adsorption selectivity coefficient of $CO_2/CH_4$ achieves as high as 20.8 over CMSs obtained under the methane flow rate of $30mL\;min^{-1}$ at $800^{\circ}C$ for 70 min. The study demonstrates the prepared CMSs are a candidate adsorbent for $CO_2/CH_4$ separation.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1065-1068
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• 1998

On the study, The activated carbon assemblies(ACA) were prepared by activation of the coated glass mate(woven type) with phenolic resin at $700^{\circ}C$ under $N_2$ after drying and curing processes. Surface of the ACA was continuously modified with $N_2$, $CO_2$ or $NH_3$ at $700^{\circ}C$ for 2 hour for comparison of adsorptive characteristics between the ACA and commercial activated carbon cloth. The ACA showed high surface areas up to $2440\;m^2/g$ when converted into the coated carbon base, and the surface was investigated by FT-IR and XPS. The basic ACA modified with $NH_3$ displayed the efficient removal capability of $SO_2$, which is 75% of that in commercial activated carbon cloth. Therefore, it has proved the applicability of ACA as an inexpensive materials for Dry de-SOX system.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.717-720
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• 1998

On the study, The activated carbon assemblies(ACA) were prepared by activation of the coated glass mat(woven type) with phenolic resin at $700^{\circ}C$ under $N_2$ after drying and curing processes. Surface of the ACA was continuously modified with $N_2$, $CO_2$ or $NH_3$ at $700^{\circ}C$ for 2 hour for comparison of adsorptive characteristics between the ACA and commercial activated carbon cloth. The ACA showed high surface areas up to $2440\;m^2/g$ when converted into the coated carbon base, and the surface was investigated by FT-IR and XPS. The basic ACA modified with $NH_3$ displayed the efficient removal capability of $SO_2$, which is 75% of that in commercial activated carbon cloth. Therefore, it has proved the applicability of ACA as an inexpensive materials for Dry de-SOX system.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.397-400
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• 1998

On the study, The activated carbon assemblies(ACA) were prepared by activation of the coated glass mat(woven type) with phenolic resin at $700^{\circ}C$ under $N_2$ after drying and curing processes. Surface of the ACA was continuously modified with $N_2$, $CO_2$ or $NH_3$ at $700^{\circ}C$ for 2 hour for comparison of adsorptive characteristics between the ACA and commercial activated carbon cloth. The ACA showed high surface areas up to $2440\;m^2$/g when converted into the coated carbon base, and the surface was investigated by FT-IR and XPS. The basic ACA modified with $NH_3$ displayed the efficient removal capability of $SO_2$, which is 75% of that in commercial activated carbon cloth. Therefore, it has proved the applicability of ACA as an inexpensive materials for Dry de-SOX system.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.219.2-219.2
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• 2011

The oxyfluorination effects of electrospun carbon nanofibers (OFACFs) were investigated for $CO_2$ storage. Carbon nanofibers were prepared form poly acrylonitrile / N,N-dimethylformamide solution through electrospinning method and heat treatment. Chemical activation of carbon nanofibers were carried out in order to improve the pore structure. And the surface modification of activated carbon nanofibers was conducted by oxyfluorination to improve the $CO_2$ storage on effect of introduced functional groups. The samples were labeled CF (electrospun carbon nanofiber), ACF (activated carbon nanofibers), OFACF-1 ($F_2:O_2$ = 3:7), OFACF-2 ($F_2:O_2$ = 5:5) and OFACF-3 ($F_2:O_2$ = 7:3). The functional group of OFACFs was investigated by x-ray photoelectron spectroscopy analysis. The specific surface area, pore volume and pore size of OFACFs were calculated and pore shape was estimated by the BET equation. Through the adsorption isotherm, the specific surface area and pore volume significantly decreased by oxyfluorination.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2468-2473
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• 2018

Nitrogen-doped activated carbon fibers (ACFs) were prepared by chemical vapor deposition using melamine powder and acetonitrile for introducing quaternary nitrogen on the commercial ACFs, subsequently heated at $950^{\circ}C$ and activated by steam. Adsorption experiments of nitrate in aqueous solution were also conducted to evaluate adsorption capacity of the prepared ACFs using ion chromatography. The amount of introduced nitrogen content and nitrogen species on activated carbon fibers was examined by CHN elemental analyzer and X-ray photoelectron spectroscopy, respectively. As a result, adsorption capacity of quaternary nitrogen-doped ACF (ST-ML-AN-ST) was 0.75 mmol/g, indicating ca. two-times higher than that of untreated ACF (0.38 mmol/g). According to the adsorption data, the Langmuir isotherm model was the best fit. The prepared samples were also regenerated using hydrochloric acid. After regeneration, the adsorption capacity of the nitrogen-doped ACF (ST-ML-AN-ST) showed ca. 80% on average, implying that a portion of nitrates was adsorbed on the prepared ACFs irreversibly.

• Carbon letters
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• v.8 no.3
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• pp.199-206
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• 2007

The activated carbon produced from rubber wood sawdust by chemical activation using phosphoric acid have been utilized as an adsorbent for the removal of Cu(II) from aqueous solution in the concentration range 5-40 mg/l. Adsorption experiments were carried out in a batch process and various experimental parameters such as effect of contact time, initial copper ion concentration, carbon dosage, and pH on percentage removal have been studied. Adsorption results obtained for activated carbon from rubber wood sawdust were compared with the results of commercial activated carbon (CAC). The adsorption on activated carbon samples increased with contact time and attained maximum value at 3 h for CAC and 4 h for PAC. The adsorption results show that the copper uptake increased with increasing pH, the optimum efficiency being attained at pH 6. The precipitation of copper hydroxide occurred when pH of the adsorbate solution was greater than 6. The equilibrium data were fitted using Langmuir and Freundlich adsorption isotherm equation. The kinetics of sorption of the copper ion has been analyzed by two kinetic models, namely, the pseudo first order and pseudo second order kinetic model. The adsorption constants and rate constants for the models have been determined. The process follows pseudo second order kinetics and the results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. It was concluded that activated carbon produced using phosphoric acid has higher adsorption capacity when compared to CAC.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.103-110
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• 2014

Sisal fiber, an agricultural resource abundantly available in china, has been used as raw material to prepare activated carbon with high surface area and huge pore volume by chemical activation with zinc chloride. The orthogonal test was designed to investigate the influence of zinc chloride concentration, impregnation ratio, activation temperature and activation time on preparation of activated carbon. Scanning electron micrograph, Thermo-gravimetric, $N_2$-adsorption isotherm, mathematical models such as t-plot, H-K equation, D-R equation and BJH methods were used to characterize the properties of the prepared carbons and the activation mechanism was discussed. The results showed that $ZnCl_2$ changed the pyrolysis process of sisal fiber. Characteristics of activated carbon are: BET surface area was $1628m^2/g$, total pore volume was $1.316m^3/g$ and ratio of mesopore volume to total pore volume up to 94.3%. These results suggest that sisal fiber is an attractive source to prepare mesoporous high-capacity activated carbon by chemical activation with zinc chloride.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1097-1101
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• 2002

Activated carbon is amorphous and its intraparticle pores are well developed. Thus it has high adsorption capabilities and catalytic effect, and is utilized in many areas of industries such as food processing. In recent years, the demand of activated carbon has been increased to solve the environmental problems-waste treatment and removal of poisonous gas. Therefore, in this study an activated carbon was made using the waste and then the industrial characteristics of the produced activated carbon were investigated. The result showed that the carbonization yield was decreased when carbonization temperature was increased from 400 to $600^{\circ}C$ and that the optimal carbonization temperature was $500^{\circ}C$. The optimal concentration of NaOH for removing ash in the raw sample was 1~2N. The iodine adsorption of activated carbon using waste sample at $500^{\circ}C$ carbonization was 1204.28mg/g. The activation result of carbonization sample showed that the optimal activation condition was the carbonization at $500^{\circ}C$ and the activation at $800^{\circ}C$. So the production of activated carbon was thought to be possible, reused as resource, and decreased the environmental pollution.