• 한국농공학회논문집
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• 제51권4호
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• pp.21-27
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• 2009

This study was performed to evaluate the physical and mechanical properties of porous concrete using waste activated carbon. Material used were ordinary portland cement, recycled coarse aggregate, waste activated carbon and superplasticizer. The replacement ratios of waste activated carbon were 0,1,2,3,4,5,6,7,8,9, and 10 %. The void ratio was decreased and ultrasonic pulse velocity was increased with increasing the waste activated carbon powder, respectively. The compressive strength and flexural strength of porous concrete using waste activated carbon powder were in the range of 8.21${\sim1}$6.58 MPa and 1.69${\sim1}$3.68 MPa, respectively. The pH degree of porous concrete in 1day and 77days were shown in 12.50${\sim1}$12.63 and 10.21${\sim1}$10.70, respectively. Accordingly, waste activated carbon can be used for porous concrete material.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2010-2012
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• 2005

Activated carbon was activated with chemical treatment to attain high surface area with porous structure. We have been considered activated carbon is the ideal material for high voltage electric double layer capacitor due to their high specific surface area, good conductivity and chemical stability. In this study we found that increase in electrochemical capacitance due to activated carbon. Also chemically activated carbon and water treatment have resulted larger capacitance and also exhibits better electrochemical behavior, and is about 15% more than in untreated state. The structural change in activated carbon through chemical treatment activation was investigated by using SEM and XRD. In this study, the dependence of the activation behavior with KOH in the micro structure of host materials will be discussed. Furthermore, the relation to the electric double layer capacitance, especially the specific capacitance per unit area, is also discussed.

• 한국재료학회지
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• 제29권10호
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• pp.623-630
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• 2019

Because of their excellent stability and highly specific surface area, carbon based materials have received attention as electrode materials of electrical double-layer capacitors(EDLCs). Biomass based carbon materials have been studied for electrode materials of EDLCs; these materials have low capacitance and high-rate performance. We fabricated tofu based porous activated carbon by polymer dissolution reaction and KOH activation. The activated porous carbon(APC-15), which has an optimum condition of 15 wt%, has a high specific surface area($1,296.1m^2\;g^{-1}$), an increased average pore diameter(2.3194 nm), and a high mesopore distribution(32.4 %), as well as increased surface functional groups. In addition, APC has a high specific capacitance($195F\;g^{-1}$) at low current density of $0.1A\;g^{-1}$ and excellent specific capacitance($164F\;g^{-1}$) at high current density of $2.0A\;g^{-1}$. Due to the increased specific surface area, volume ratio of mesopores, and surface functional groups, the specific capacitance and high-rate performance increased. Consequently, the tofu based activated porous carbon can be proposed as an electrode material for high-performance EDLCs.

• 공업화학
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• 제20권5호
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• pp.465-472
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• 2009

본 총설에서는 최근 주로 연구되고 있는 활성탄, 탄소나노튜브, 팽창 흑연 및 활성 탄소 섬유 등 다공성 탄소재료를 중심으로 수소 저장량을 증대시키기 위한 기술 및 기 발표된 수소저장량과 그 장 단점에 대하여 고찰하였다. 수소저장능을 향상시키기 위한 탄소 내 기공의 최적의 크기는 0.6~0.7 nm로 조사되었다. 촉매의 경우 전이금속 및 그 금속산화물이 많이 이용되었으며, 주로 다공성 탄소재료에 도핑을 통해 수소저장능을 향상시켰다. 수소저장 매체인 다공성 탄소재료 중에서 활성탄은 대량생산이 가능하여 가격이 비교적 저렴한 장점이 있고 탄소나노튜브는 튜브의 튜브간 공간 외에도 내부공간에 수소를 저장할 수 있는 공간이 수소저장에 활용될 수 있다는 장점이 있다. 팽창 흑연은 흑연의 층 사이에 알칼리 금속의 삽입 시 층간 거리가 팽창하여 수소저장에 용이하고, 활성탄소섬유는 높은 비표면적과 발달된 미세기공이 수소흡착에 크게 기여한다는 점이 있다. 이러한 기존의 연구로 고려해 볼 때 다공성 탄소재료는 아직 달성되지 못한 DOE의 수소저장 목표치에 도달하기 위한 주요 유망한 후보재료 중의 하나이다.

• 한국응용과학기술학회지
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• 제37권5호
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• pp.1200-1207
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• 2020

본 연구에서는 다공성 활성탄소와 금속유기골격체 복합재료 기반의 전극 재료와 "이온젤" 이라고 불리는 고분자 고체 전해질을 이용하여 슈퍼커패시터를 제작 하였으며, 금속유기골격체의 함량에 따른 전기화학적 거동을 관찰하여 보았다. 슈퍼커패시터의 전기화학적 특성은 순환전압전류법(CV), 전기화학적 임피던스 분광법(EIS) 및 전정류 충·방전법(GCD)으로 분석하였으며, 그 결과로, 다공성 활성탄소 대비 금속유기골격체를 0.5 wt% 첨가 하였을 때 가장 높은 전기용량값을 확인 할 수 있었으며, 0.5 wt% 이상의 금속유기골격체의 함유량은 전기화학적 특성 감소에 영향을 주는 것으로 사료되며, 이러한 결과를 바탕으로 제조된 다공성 활성탄소/금속유기골격체 복합재료 기반의 슈퍼커패시터는 다양한 분야에 활용이 가능할 것으로 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.31-37
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• 2002

This paper was investigated to clarify the possibility of a biodegradation of materials adsorbed on different porous granular-activated carbons (GACs) such as coal-& coconut-based GAC. Total organic carbon, humic substance and ammonia were used to compare their removal efficiencies. The objective of this study is to determine the adsorption capacity of bioregenerated GAC. When raw water reacted with chloride, the yield of THMs increased as a function of the input amount of chloride. The formation of trihalomethanes (THMs) was investigated in water treated with chlorine when humic acid was used as THM precursor. As the input amount of chloride in raw water increased by two or five-fold to remove the $NH_3$, the chloroform of the THMs significantly increased also five or ten-fold. It was found that the chloroform was significantly removed by the treatment of biological activated carbon (BAG) in comparison with the ozone treatment, and the removal efficiency of THMs in coal-typed GAC was $10-30\%$ better than coconut-typed GAC due to the biological degradation on the surface of the activated carbons.

• Carbon letters
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• 제24권
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• pp.73-81
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• 2017

Interconnected meso/microporous activated carbons were prepared from pumpkin seeds using a simple chemical activation method. The porous carbon materials were prepared at different temperatures (PS-600, PS-700, PS-800, and PS-900) and demonstrated huge surface areas ($645-2029m^2g^{-1}$) with excellent pore volumes ($0.27-1.30cm^3g^{-1}$). The well-condensed graphitic structure of the prepared activated carbon materials was confirmed by Raman and X-ray diffraction analyses. The presence of heteroatoms (O and N) in the carbon materials was confirmed by X-ray photoemission spectroscopy. High resolution transmission electron microscopic images and selected area diffraction patters further revealed the porous structure and amorphous nature of the prepared electrode materials. The resultant porous carbons (PS-600, PS-700, PS-800, and PS-900) were utilized as electrode material for supercapacitors. To our delight, the PS-900 demonstrated a maximum specific capacitance (Cs) of $303F\;g^{-1}$ in 1.0 M $H_2SO_4 $ at a scan rate of 5 mV. The electrochemical impedance spectra confirmed the poor electrical resistance of the electrode materials. Moreover, the stability of the PS-900 was found to be excellent (no significant change in the Cs even after 6000 cycles).

• 한국산업융합학회 논문집
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• 제9권1호
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• pp.87-91
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• 2006

This research exposes the process of carbonization of solid waste from the city and the method of activated, as well as the process of meso-porous under several test conditions. In addition, it is expected that the active carbon obtained through this process can be used as filter for air and sewage treatment, and can absorb dioxin(as almost 60-80% of meso-porous and porous properties area) unlike the existing active carbon.

• Carbon letters
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• 제25권
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• pp.103-112
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• 2018

Hierarchically porous, chemically activated carbon materials are readily derived from biomass using hydrothermal carbonization (HTC) and chemical activation processes. In this study, empty fruit bunches (EFB) were chosen as the carbon source due to their sustainability, high lignin-content, abundance, and low cost. The lignin content in the EFB was condensed and carbonized into a bulk non-porous solid via the HTC process, and then transformed into a hierarchical porous structure consisting of macro- and micropores by chemical activation. As confirmed by various characterization results, the optimum activation temperature for supercapacitor applications was determined to be $700^{\circ}C$. The enhanced capacitive performance is attributed to the textural property of the extremely high specific surface area of $2861.4m^2\;g^{-1}$. The prepared material exhibited hierarchical porosity and surface features with oxygen functionalities, such as carboxyl and hydroxyl groups, suitable for pseudocapacitance. Finally, the as-optimized nanoporous carbons exhibited remarkable capacitive performance, with a specific capacitance of $402.3F\;g^{-1}$ at $0.5A\;g^{-1}$, a good rate capability of 79.8% at current densities from $0.5A\;g^{-1}$ to $10A\;g^{-1}$, and excellent life cycle behavior of 10,000 cycles with 96.5% capacitance retention at $20A\;g^{-1}$.

• 한국세라믹학회지
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• 제42권7호
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• pp.469-474
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• 2005

Activated Carbon Fibers (ACFs) are widely used as adsorbents in technologies related to pollution abatement due to their highly porous structure and large adsorption capacity. The porous structure and surface area of ACFs depends strongly on both the activation processes arid the nature .of the precursors. The chemical activation with hydroxides has recently been, of great interest as it permits the preparation of activated carbon fibers with highly developed porosity. In this work, OXI-PAN fiber used as precursor for the preparation of activated carbon fibers by chemical activation with KOH and NaOH. The affects of several activation conditions on the surface properties, pore size distribution and adsorption capacity of Ag ion and Iodine ion on ACFs studied.