• Carbon letters
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• 제9권2호
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• pp.137-144
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• 2008

The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

• 환경위생공학
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• 제14권2호
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• pp.18-24
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• 1999

The purpose of this study was carried out to estimate removal possibility of IBMP and IPMP causing odor in raw water. As a result of Freundlich isotherm. IBMP was superior to IPMP in adsorptive capacity. Adsorptive capacities of activated carbon were found to be in order of Lignite, Coconut shell, and Charcoal. These were well fitted with Freundlich isotherm. According to adsorption breakthrough tests for Lignite GAC, breakthrough time of IPMP and IBMP were 5.7hr and 5.5hr, respectively. Because adsorptive capacities of target material were very different with pore size distribution, it seemed that Lignite and Coconut shell based activated carbons were recommended in order to remove door compounds.

• 한국환경과학회지
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• 제2권1호
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• pp.73-81
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• 1993

Adsorption process using granular activated carbon(GAC) has been considered as one of the most effective water treatment technologies to remove humic acid which is recon- niEed as trihalomethane(THM) precursor in chlorination. To design the most effective GAC process, it is necessary to conduct the test of adsor- ption performance by means of isothem, batch rate and column studies and to select the most effective activated carbon according to raw materials of GAC - lignite and coconut shell. The objective of this study is to investigate the adsorption performance of humid acid on two activated carbons - lignite activated carbon(LAC) and coconut shell activated car- bon(CAC) made in Korea. It is available to represent UV-abs and trihalomethane formation potential(THMFP) as concentration of humic acid due to good relationship. The adsorption capacity of humid acid is not concerned with surface area of activated carbon but with pore size related to about $100{\AA}$, and then LAC forming at the extent of mesopore is found to be eight times more effective in adsorption capacity than CAC forming at micropore. The adsorption capacity of LAC and CAC is better at pH 5.5 than at pH 7. Pore and surface diffusion coefficients calculated from the diffusion model are $7.61\times10^{-13}m^2/sec$, $3.52\times10^{-15}m^2/sec$ for CAC, and $3.38\times10^{-12}m^2$/sec and $Ds=1.48{\times}10^{-15}m^2/sec$ for GAC respectively. From the results of column test it shows that the performance of LAC is also better than CAC and the optimal EBCT(Empty Bed Contact Time) is 4.52min. and activated carbon removes selectively the components of humic acid to be easily formed to THM.

• 한국축산시설환경학회지
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• 제13권3호
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• pp.211-218
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• 2007

본 시험은 축분을 이용한 활성탄소를 제조하는 기술을 개발하고 이의 활용방안을 연구하여 축분의 처리방법을 다변화하고 제조된 활성탄소의 토양개량재, 악취흡착재 등 농업적 이용을 모색하기 위하여 악취제거시험 등을 수행하였으며 그 결과는 다음과 같다. 1. 가축분을 건조, 펠렛화 과정을 거친 후 $400^{\circ}C$에서 1시간 탄화처리하고 $750^{\circ}C$에서 1시간 활성화처리시 활성탄소가 제조되었다. 2. 축분의 회분 함량은 돈분퇴비가 11.9%로 낮았으나 계분퇴비 29.8%, 젖소깔짚 40.7%로 높았다. 휘발성물질은 젖소깔짚 11.6%, 계분퇴비 18.8%, 계분 31.0%, 돈분퇴비 22.3% 이었으나 육계깔짚은 49.8%로 높았다. 3. 축분활성탄소의 비표면적은 계분퇴비 259.8, 계분 209.8, 돈분퇴비 442.3, 젖소깔짚 $812.9\;m^2/g$으로 야자각 활성탄소 $1,040\;m^2/g$ 보다 낮았으며 미세기공의 크기는 육계깔짚 $5.02\;{\AA}$으로서 큰 반면 젖소깔짚은 $0.39\;{\AA}$으로 야자각 활성탄소와 비슷하였다. 4. 축분활성탄소의 요오드 흡착능력은 $530{\sim}580mg/g$으로 야자각 활성탄소의 1,000 mg/g 보다 낮았다. 5. 암모니아가스의 흡착율은 계분이나 계분퇴비로 만든 활성탄소가 가장 낮았으며 젖소깔짚 활성탄소가 가장 높았으며 계분퇴비 활성탄소는 20분 경에 흡착 포화에 도달하는 반면 젖소깔짚 활성탄소는 40분이 되어서 흡착 포화에 도달하였다. 6. 황화수소의 경우 휘발성물질이 비교적 많은 육계깔짚, 계분퇴비, 산란계분 등으로 만든 활성탄소에서 흡착율이 낮았으며 젖소깔짚 활성탄소에서 높았다.

• Carbon letters
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• 제3권4호
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• pp.205-209
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• 2002

In the reaction of gas-solid phases, the microwave energy plays a role as a catalyst, because it causes friction between adjacent molecules and enables an unique characteristics of interior heating of the materials. When the dipole gases are adsorbed inside of the pore of carbon materials, the gases are decomposed by the microwave energy and reacted with the carbon atoms. Using this principle, we could make the activated carbon from coconut shell within 20 minute, and this residence time for activation is about 1/16 of rotary kiln. The BET surface area of activated carbon made by microwave is about $1,100m^2/g$ similar to conventional method of rotary kiln. In this study, the power of microwave generator was 400~1000W, and the gas for activation was steam mainly.

• Carbon letters
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• 제11권1호
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• pp.13-21
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• 2010

Coconut shell activated carbon (CSAC) was investigated for its ability in the removal of two neutral chlorinated organic compounds, namely trichloroethylene (TCE) and dichloromethane (DCM) from aqueous solution using a packed bed column. The efficiency of the prepared activated carbon was also compared with a commercial activated carbon (CAC). The important design parameters such as flow rate and bed height were studied. In all the cases the lowest flow rate (5 mL/min) and the highest bed height (25 cm) resulted in maximum uptake and per cent removal. The experimental data were analysed using bed depth service time model (BDST) and Thomas model. The regeneration experiments including about five adsorption-desorption cycles were conducted. The suitable elutant selected from batch regeneration experiments (25% isopropyl alcohol) was used to desorb the loaded activated carbon in each cycle.

• 한국산업보건학회지
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• 제8권1호
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• pp.115-123
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• 1998

Vinyl chloride monomer exists as gas phase at normal temperature and reacts with oxygen and strong oxidant in the air to form oxidized materials. Because of being easily synthesized, it is used as a main source at the synthetic reaction process of PVC synthesis factories. Ministry of Labor regulates its usage as a carcinogen and its exposure level as 1 ppm. But the amount of VCM production in PVC and VCM production process hasn't been exactly estimated. In addition, facilities of this factory are located in outdoor. Therefore, this study was designed to investigate effects of temperature on breakthrough of charcoal tube at a fixed concentration and temperature during VCM sampling based on NIOSH and OSHA methods which were used as methods of occupational environment measuring and analysis. During the sampling of VCM, methods of OSHA and NIOSH require flow rate of 0.05 lpm and sampling volume of $3{\ell}$, $5{\ell}$ respectively, at this time carbon molecular sieve tube and coconut shell charcoal tube are used to observe the breakthrough along with concentration and temperature. As a result, significant difference between average adsorbed amounts of OSHA methods but that of NIOSH methods cannot be found. NIOSH method is likely to be effected by high temperature and normal temperature in high concentration. Breakthrough is not found in the method of OSHA at different conditions of temperature and concentration. As the result of this study we could verify that breakthrough occurred in the process of sampling VCM with NIOSH methods. Therefor in summer time, breakthrough should be considered and research on the breakthrough volume should be done. It is considered the research about the specificity of the coconut shell charcoal and carbon molecular sieve sorbent should be done when sampling VCM in comming days.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2003년도 추계정기총회 및 국제심포지엄
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• pp.170-173
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• 2003

Activated Rice-Hull carbon was developed to remove ammonia compounds in water matrix. Isotherm adsorption tests of ammonia were conducted using a bottle-point technique and column test. Residual ammonia after Jar-Test or passing through the column was determined by Indophenol method, and assessed the removal efficiency for ammonia of the adsorbent. As a result, the adsorption capacity for ammonia of activated racehull carbon was very larger than that of coconut shell carbon, because the rice hull carbon had the higher BET surface area of silicate. The activated racehull carbon is under the development as adsorbent to remove ammonia in drinking water and waste water.

• 공업화학
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• 제27권6호
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• pp.590-598
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• 2016

본 연구는 흡착제로 야자각계 수증기 활성화 입상 활성탄을 사용하여 Acid Black 1 수용액에서의 흡착 거동과 동역학적, 열역학적 파라미터에 대해 회분식 반응을 통해 조사하였다. 흡착변수로는 pH, 초기농도, 접촉시간, 온도를 사용하였다. pH에 대한 영향을 조사하기 위해 pHpzc 값을 분석한 뒤 pH 3-11 범위에서 제거율을 조사하였다. 흡착평형자료로부터 Langmuir, Freundlich, Temkin, Dubinin-Radushkevich 등온 흡착식에 대한 적합성을 평가하였다. 흡착공정에 대한 동역학적 해석을 통해 유사 1차반응식과 유사 2차반응식에 대한 흡착반응의 일치도를 평가하였다. 열역학적 해석을 통해 엔탈피 변화 값과 활성화에너지 값을 조사하여 이를 통해 흡착공정이 흡열반응인지를 확인하였으며, 엔트로피 변화 값과 자유에너지 값을 통해 흡착공정의 자발성을 확인하였다.

• Korean Chemical Engineering Research
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• 제53권3호
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• pp.309-314
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• 2015

야자계 활성탄을 사용하여 수용액으로부터 brilliant blue FCF 염료의 흡착에 대해 조사하였다. 회분식 실험은 흡착제의 양, 초기농도와 접촉시간과 온도를 흡착변수로 사용하여 수행하였다. 흡착평형자료는 Langmuir와 Freundlich 식을 사용하여 해석하였으며, Freundlich 식이 더 좋은 일치도를 나타냈다. 평가된 Freundlich 상수(1/n=0.129~0.212)로부터 활성탄에 의한 brilliant blue FCF의 흡착조작이 적절한 처리방법이 될 수 있음을 알았다. 흡착속도실험자료를 유사일차반응속도식과 유사이차반응속도식에 적용해 본 결과, 흡착동력학은 유사이차반응속도식에 잘 맞는 것으로 나타났다. 음수값의 Gibbs 자유에너지(-4.81~-10.33 kJ/mol)와 양수값의 엔탈피(+78.59 kJ/mol)는 흡착이 자발적이고 흡열공정으로 진행된다는 것을 나타낸다.