• Carbon letters
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• v.16 no.1
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• pp.11-18
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• 2015

The process of oxidizing polyacrylonitrile (PAN)-based carbon fibers converts them into an infusible and non-flammable state prior to carbonization. This represents one of the most important stages in determining the mechanical properties of the final carbon fibers, but the most commonly used methods, such as thermal treatment ($200^{\circ}C$ to $300^{\circ}C$), tend to waste a great deal of process time, money, and energy. There is therefore a need to develop more advanced oxidation methods for PAN precursor fibers. In this review, we assess the viability of electron beam, gamma-ray, ultra-violet, and plasma treatments with a view to advancing these areas of research and their industrial application.

• Textile Coloration and Finishing
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• v.4 no.4
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• pp.90-96
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• 1992

In the PAN-based ACF manufacturing system stabilization step was improved with chemical treatment (preoxidation) in order to yield higher carbon content and to avoid excessive fragmentation during carbonization and activation process. The optimal condition of preoxidation was at 18$0^{\circ}C$ for 4 minutes in sodium glyceroxide in glycerine (concentration of NaOH was 0.02 meq/g). To investigate low temperature stabilization effect, preoxidized PAN fiber heated 22$0^{\circ}C$ to 26$0^{\circ}C$ as a function of treatment time and oxidative gas atmosphere, and analysed by infrared spectrum and TGA. As a results of IR and TGA, it was clear that impregnated[preoxidative] PAN had 14% higher residual than untreated PAN at 100$0^{\circ}C$ and the optimal condition of stabilization was at 26$0^{\circ}C$ for 3.5 hours within $N_2$ atmosphere.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.841-846
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• 2014

It found that the maximum temperature of the arc discharge occurred on the Silicone rubber sample significantly decreased with increasing the reinforcing agent. It was confirmed that the current value decreased with increasing the aluminium trihydrate($Al(OH)_3$) and the current value increased with reducing the primary resistance over time. Regarding these results, may be it is because the degradation due to the electro-conductive carbonization was improved and the properties of dielectric breakdown was reduced by the flame retardant reinforcing agent. It found that the electro-conductive carbonized road has not happened by increasing the flame retardant reinforcing agent. Regarding to the arc discharge, this study show that the arc arising near the lower electrode of sample has disappeared.

• Journal of Integrative Natural Science
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• v.4 no.1
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• pp.15-22
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• 2011

In this study, liquid with carbonized artemisia was developed for the first time that can be used as food additives and outside medicinal agents by burning artemisia species such as Artemisia dubia wall, Artemisia capillaris Thunb, Artemisia montana (Nakai) Pamp), Artemisia keiskeana Miq, Leonurus Japonicus Houtt. etc. In addition, edibility of recovered liquid with carbonized artemisia was verified by comparing the contents according to each ingredient with common refined pyroligneous liquid through the analysis of 9 kinds of organic acid by the species of artemisia, methanol and ethanol. Besides, the result of antimicrobial activities on six kinds of food spoilage and food poisoning bacteria observed by paper disc method for liquid with carbonized artemisia indicated that those two liquids showed strong antimicrobial. At the concentration of 1.5 mg/disc, clear zone for S. sonnei and S. aureus, L. monocytogenes was 13~16 mm, and they showed stronger antimicrobial activities than other strain.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.166-172
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• 2004

The activated carbon was produced from Sancheong bamboo by steam and carbon dioxide gas activation methods. The carbonization of raw material was conducted at 90$0^{\circ}C$ and gas activation reactions were conducted with respect to various conditions. -activation temperature 750-90$0^{\circ}C$, the flow rate of steam 0.5-2g-$H_2O$/g-char$.$hr, the flow rate of carbon dioxide 5-30$m\ell$-$CO_2$/g-char-min and activation time 1-5 hr. The prepared activated carbons were measured yield, the adsorption capacity of iodine and methylene blue, BET specific surface area and pore size distribution. The adsorption capacity of iodine (680.5-1526.1 mg/g) and methylene blue (18.3-221.5 mg/g) increased with creasing activation temperature and activation time. The adsorption capacity of iodine and methylene blue increased with the activation gas quantity in the range of 0.5-1.5g-$H_2O$/g-charㆍhr, 5-18.9$m\ell$-Co$_2$/g-charㆍmin. But those decreased over those range due to the pore shrinkage. The steam activation method was superior in efficiency to carbon dioxide activation method.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.151-158
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• 2020

ACF preparation from different materials has been attached with great attention during these years. This study was conducted to prepare activated carbon fiber (ACF) from luffa through the processes i.e pre-treatment, pre-oxidation and carbonization activation. Besides, this study also characterizes the ACF and its effect, i.e effect of pre-oxidation time and temperature also activation time and temperature on the compressive strength of ACF were investigated. The results from SEM, BET, FTIR and XRD show that the ACF is very efficient. The products under the optimum conditions had a specific surface area of 478.441 m2 /g with an average pore diameter of 3.783nm, and a pore volume of 0.193 cm3 /g. The surface of the luffa fiber is degummed and exposed, which is beneficial to the subsequent process and the increase of product properties. The compressive strength of HP-ACF was prepared under the optimum conditions, which can reach 0.2461 MPa. ACF is rich in micro-pores and has a good application prospect in the field of environmental protection.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1175-1186
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• 2020

In this study, the problem is analyzed, and methods of improvement are presented. For evaluating the performance of the proposed EGT sensor, a complex environment test equipment has been developed to test both high temperature and vibration conditions at the same time. This equipment evaluates the accuracy and response time of the EGT sensor. In the results of the comparison test of the complex environment test equipment of heat and vibration, the existing sensor showed a carbonization problem, and the proposed sensor showed no problem. Therefore, it is expected that the improved EGT sensor will be able to be applied to various industrial fields, including gas turbines for power generation.

• Analytical Science and Technology
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• v.28 no.1
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• pp.40-46
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• 2015

Hydrochar has been generated from food waste via hydrothermal carbonization (HTC) reaction. As a solid product of HTC reaction, hydrochar has a great potential as an adsorbent of pollutants from the various media. The surface area and pore volumes are very important parameters to be served as an adsorbent. It requires an expensive equipment and consumes time to measure those parameter. Therefore, titration methods including iodine and methylene blue adsorption were evaluated to be correlated with that of BET analysis. Even though the absolute values of the computed surface area and pore volumes were not able to be matched directly, the patterns of change were successfully correlated. Among the reaction conditions, the reaction time and temperature at $230^{\circ}C$ for 4 h was determined as an optimization condition, which confirmed by titration method and BET analysis. Titration method for surface area and pore volumes computed by combination of iodine and methylene blue adsorbing values would be a simple and fast way of determining the optimization condition for hydrochar as an adsorbent produced by HTC reaction.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.302-314
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• 2015

There is an adsorption method using activated carbon as a typical method for removing elemental mercury. Physical characteristics of activated carbon such as specific surface area and volume of pore (micro and meso) have positive effect for mercury adsorption. Activated carbon is carbon-based material with a high specific surface area. This activated carbon can be manufactured through carbonization and activation process. In this process, physical characteristics of specific surface area and pore distribution are changed by controlling operating parameters like temperature, time and reagent of activation. In this study, we evaluated characteristics of activated carbons manufactured from pinewood and coal with the operating parameters. We evaluated mercury adsorption capacities of the activated carbons having excellent physical characteristics and compared those to the commercial activated carbon.

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1091-1098
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• 2007

Activated carbon was prepared from waste citrus peels by chemical activation with $ZnCl_2$. The optimal condition of carbonization was at $300^{\circ}C$ for 1.5 hr. Activation experiments with carbonized samples prepared at optimal carboniztion condition were carried out under various conditions such as activation temperature of 400 to $900^{\circ}C$, activation time of 0.5 to 2.0 hr, and $ZnCl_2$ ratio of 100 to 300%. In order to investigate the physical properties of the activated carbons prepared, iodine adsorptivities and specific surface areas were measured and their morphologies were observed from scanning electron microscopy. As $ZnCl_2$ ratio increased, activation yield decreased, while iodine adsorptivity and specific surface area increased. The optimal condition of activation was at 300% $ZnCl_2$ ratio and $300^{\circ}C$ for 1.5 hr, and then iodine adsorptivity and specific surface area was measured as about 862 mg/g and $756m^2/g$, respectively. SEM photography showed that the surface morphology was changed and many active pore were produced by chemical activation.