열수가압탄화에 의해 제조한 폐목재 바이오차 (Bio-char) 활성탄의 특성화에 관한 연구

원민희,조우리,장진만,박지수,이재영 한국폐기물자원순환학회 2022 한국폐기물자원순환학회지 Vol.39 No.3

The market for activated carbon is growing due to environmental awareness and strengthening of environmental regulations. Biochar is a solid carbide that is produced through a hydrothermal carbonization (HTC) process. Wood is an ideal raw material for activated carbon and biomass waste wood because it has low energy consumption rates and does not require pre-treatment to remove moisture. The activated carbon samples in this study were prepared by a chemical activation process using KOH, which is mainly used for activation. The study analyzed the specific surface area, pore volume, pore size, and pore distribution by selecting four samples with high iodine adsorption capacity among the prepared activated carbon samples. The specific surface area for all four samples was between 1192.2 and 1387.1 m2/g, all of which were over 1,000 m2/g, and the pore volume was between 0.6510 and 0.8030 cm3/g. During this process, micropores with an average pore size of 21 to 25 Å were formed. SEM photography revealed that these pores were uniform and that the number of pores increased according to activation levels of the carbon samples. When the iodine adsorptivity and specific surface area of commercial activated carbon was compared with that of activated carbon prepared by waste wood biochar with KOH, the specific surface area was higher in the activated carbon samples prepared by waste wood biochar with KOH. These results indicate that the adsorption of activated carbon by waste wood biochar with KOH is successful when applied to activated carbon samples.

Synthesis of Activated Carbon from Rice Husk Using Microwave Heating Induced KOH Activation

Nguyen, Tuan Dung,Moon, Jung-In,Song, Jeong-Hwan,Kim, Taik-Nam Materials Research Society of Korea 2012 한국재료학회지 Vol.22 No.6

The production of functional activated carbon materials starting from inexpensive natural precursors using environmentally friendly and economically effective processes has attracted much attention in the areas of material science and technology. In particular, the use of plant biomass to produce functional carbonaceous materials has attracted a great deal of attention in various aspects. In this study the preparation of activated carbon has been attempted from rice husks via a chemical activation-assisted microwave system. The rice husks were milled via attrition milling with aluminum balls, and then carbonized under purified $N_2$. The operational parameters including the activation agents, chemical impregnation weight ratio of the calcined rice husk to KOH (1:1, 1:2 and 1:4), microwave power heating within irradiation time (3-5 min), and the second activation process on the adsorption capability were investigated. Experimental results were investigated using XRD, FT-IR, and SEM. It was found that the BET surface area of activated carbons irrespective of the activation agent resulted in surface area. The activated carbons prepared by microwave heating with an activation process have higher surface area and larger average pore size than those prepared by activation without microwave heating when the ratio with KOH solution was the same. The activation time using microwave heating and the chemical impregnation ratio with KOH solution were varied to determine the optimal method for obtaining high surface area activated carbon (1505 $m^2$/g).

Quality Comparison of Activated Carbon Produced From Oil Palm Fronds by Chemical Activation Using Sodium Carbonate versus Sodium Chloride

( Seri Maulina ),( Gewa Handika ),( Irvan ),( Apri Heri Iswanto ) 한국목재공학회 2020 목재공학 Vol.48 No.4

Using Na₂CO₃ versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na₂CO₃ at an activator concentration of 10% and carbonization temperature of 400 °C. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na₂CO₃-activated carbon.

약품활성화와 가스활성화에 대한 왕겨로부터 활성탄의 제조

홍종철,김명수 명지대학교 대학원 1998 대학원논문집 Vol.2 No.-

A series of activated carbons was prepared from rice hulls by both chemical activation with KOH and physical activation with steam and carbon dioxide. The effect of process variables such as carbonization, activation temperature, and chemical ratio on the pore structure and activation yield of the carbons was studied. When the char produced by the carbonization of the rice hulls in a stream of nitrogen at 700 ℃ was well mixed with a concentrated solution of potassium hydroxide at a KOH:char ratio of 4:1 and then the mixture was activated for 3 hours in a stream of nitrogen, high-quality activated carbons with high surface area, high pore volume, and well-developed pore structure could be prepared. The surface area and micropore volume of the chemically activated carbon were 2∼3 times higher than those obtained by physical activation.

Electrochemical behavior of pitch-based activated carbon fibers for electrochemical capacitors

Lee, H.M.,Kwac, L.K.,An, K.H.,Park, S.J.,Kim, B.J. Pergamon ; Elsevier Science Ltd 2016 Energy Conversion and Management Vol.125 No.-

In the present study, electrode materials for electrochemical capacitors were developed using pitch-based activated carbon fibers with steam activation. The surface and structural characteristics of activated carbon fibers were observed using scanning electron microscopy and X-ray diffraction, respectively. Pore characteristics were investigated using N<SUB>2</SUB>/77K adsorption isotherms. The activated carbon fibers were applied as electrodes for electrical double-layer capacitors and analyzed in relation to the activation time. The specific surface area and total pore volume of the activated carbon fibers were determined to be 1520-3230m<SUP>2</SUP>/g and 0.61-1.87cm<SUP>3</SUP>/g, respectively. In addition, when the electrochemical characteristics were analyzed, the specific capacitance was confirmed to have increased from 1.1F/g to 22.5F/g. From these results, it is clear that the pore characteristics of pitch-based activated carbon fibers changed considerably in relation to steam activation and charge/discharge cycle; therefore, it was possible to improve the electrochemical characteristics of the activated carbon fibers.

금속(Ag, Cu, Co)함유 활성탄소섬유의 미세공도와 금속입자의 거동

임광순,엄상용,유승곤,Edie, Dan D. 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

개질된 석유 피치에 금속(Ag, Cu, Co)염들을 혼합하여 전구체 피치를 만들고 용융방사하여 금속함유 탄소섬유를 만든 후, 이를 수증기로 활성화하여 활성탄소섬유를 만들고 미세공도와 금속 입자의 거동을 관찰하였다. 전구체 피치의 용융방사온도는 금속함량이 증가함에 따라 선형적으로 증가했다. Co와 Cu가 함유된 탄소섬유는 공기분위기에서 400℃에서부터, Ag이 함유된 탄소섬유는 금속이 함유되지 않은 탄소섬유와 같이 480℃에서부터 급격히 분해되었다. 금속을 함유하지 않은 활성탄소섬유의 평균 기공과 비표면적은 20 Å, 1,100㎡/g이었다. 금속함유 활성탄소섬유는 금속의 촉매적 가속 때문에 활성화 속도가 크고 평균기공직경과 중기공 비율은 커졌으나, 비표면적은 감소하였다. 금속 함유 활성탄소섬유는 1 wt%가 함유되어도 각각의 금속에 대응하는 피크가 나타났다. 활성탄소섬유내에서 은 입자들은 비교적 균일하게 분포되었으나, 구리와 코발트 입자들은 일부가 합체하여 큰 입자를 형성하는 경향을 보였으며, 합체된 구리입자들은 수증기 활성화동안 일부가 섬유로부터 빠져나와 표면에 거대 기공을 남겼다. Metal (Ag, Cu, Co)salts were mixed to reformed petroleum pitches for production of metal-containing carbon fibers. The carbon fiber was steam activated to investigate the microporosity and the behaviour of metal particles in activated carbon fiber. The melt spinning temperature of precursor pitch linearly increased as the metal content increased. Cobalt and copper-containing carbon fibers were decomposed after 400℃, silver-containing and non-metal containing carbon fibers were decomposed after 480℃ in air. The average pore diameter and specific surface area of non-metal containing activated carbon fibers were 20 Å and 1,100 ㎡/g. The activation rates of metal-containing carbon fibers increased by catalytic acceleration of metals. Average pore diameter and mesopore fraction of metal-containing activated carbon fiber increased as the metal content increased, however, specific surface area decreased. The metal-containing activated carbon fibers showed peaks corresponding to their own metal. Silver particles were uniformly distributed in activated carbon fibers, while copper and cobalt particles tended to coalesence and some of coalesced copper exited from activated carbon fibers resulting in macropores on the surface of activated carbon fibers during the steam activation.

Preparation of moso bamboo columnar activated carbon with high adsorption property via polyacrylamide@asphalt adhesives and steam activation

Liu Huan,Miao Yu,Tian Huayu,Chen Yishan,Wang Enfu,Huang Jingda,Zhang Wenbiao 한국탄소학회 2024 Carbon Letters Vol.34 No.3

Moso bamboo, as a kind of renewable functional material, exhibits outstanding development potential. It is promising to prepare activated carbon with good mechanical strength and high specific surface area using moso bamboo as raw material. In this work, we employed a hydraulic extruder to extrude the bamboo charcoal and the adhesive to obtain the moso bamboo activated carbon, and improved the specific surface area of the columnar activated carbon through high-temperature water vapor activation. Through the catalytic role of the water vapor activation process, the formation and expansion of the pores were promoted and the internal pores were greatly increased. The obtained columnar activated carbon shows excellent mechanical strength (93%) and high specific surface area (791.54 m2/g). Polyacrylamide@asphalt is one of the most effective adhesives in the high-temperature water vapor activation. The average pore size (22.99 nm) and pore volume (0.36 cm3/g) of the prepared columnar activated carbon showed a high mesoporous ratio (83%). Based on the excellent pore structure brought by the activation process, the adsorption capacity of iodine (1135.75 mg/g), methylene blue (230 mg/g) and carbon tetrachloride (64.03 mg/g) were greatly improved. The resultant moso bamboo columnar activated carbon with high specific surface area, excellent mechanical properties, and outstanding adsorption capacity possesses a wide range of industrial applications and environmental protection potential.

Surface structural characterization of highly porous activated carbon prepared from corn grain

Balathanigaimani, M. S.,Shim, Wang-Geun,Kim, Chan,Lee, Jae-Wook,Moon, Hee John Wiley Sons, Ltd. 2009 Surface and interface analysis Vol.41 No.6

<P>A novel corn grain precursor was used for the preparation of activated carbon by chemical activation. The detailed investigation of the porosity development in the prepared activated carbon was done by altering the various activation conditions such as the activation temperature, activation time and ratio between the powdered form of carbonized corn grain char and KOH. The surface characteristics including the surface roughness of all the activated carbon samples were evaluated from the analysis of nitrogen (N<SUB>2</SUB>) adsorption isotherm data. At the maximum of 2978 m<SUP>2</SUP>/g, a super surface area having the corn grain-based activated carbon (CG-AC) was synthesized by using the following conditions: 1/4 ratio of powdered form of carbonized corn grain char/KOH; 800 °C; and 4 h. The possibility of preparing highly porous activated carbons with controlled porosity by varying different activation conditions was found from the pore size distribution results. In particular, the domination of the ratio between the powdered form of carbonized corn grain char and KOH on the porosity development was high compared to the activation temperature and activation time. In addition, the surface roughness calculated from the surface fractal dimension indicates the decrease of surface roughness with increasing activation conditions. Copyright © 2009 John Wiley & Sons, Ltd.</P>

은나노 활성탄에 의한 하수 2차 처리수 중의 오염물질 제거 특성에 관 한 연구

선용호(Yong-Ho Seon) 한국생물공학회 2014 KSBB Journal Vol.29 No.5

This study targets the pollutant removal of secondary effluent from final clarifiers in wastewater treatment plant using silver nanoparticles on activated carbon. The removal efficiency and treatment characteristics of pollutant are anlayzed by perfoming experiments using granular activated carbon with silver nanoparticles and ordinary granular activated carbon. The specific surface area of granular activated carbon with silver nanoparticles is smaller than that of ordinary granular activated carbon. However, the removal efficiency of CODMn, T-N and T-P in experiments using activated carbon with silver nanoparticles are higher than that in experiment using ordinary granular activated carbon. That means the case of activated carbon with silver nanoparticles is much better at treatment activity. In addition, activated carbon with silver nanoparticles has antimicrobial activity because there is no microbe on the surface of it after experiments.

Kinetic Studies on Physical and Chemical Activation of Phenolic Resin Chars

Damyanti Agarwal,Darshan Lal,V.S. Tripathi,G.N. Mathur 한국탄소학회 2003 Carbon Letters Vol.4 No.3

Granular Activated Carbon (GAC) has been proven to be an excellent material for many industrial applications. A systematic study has been carried out of the kinetics of physical as well as chemical activation of phenolic resin chars. Physical activation was carried out using CO2 and chemical activation using KOH as activating agent. There are number of factors which influence the rate of activation. The activation temperature and residence time at HTT varied in the range 550~1000℃ and ½~8 hrs respectively. Kinetic studies show that the rate of chemical activation is 10 times faster than physical activation even at much lower temperature. Above study show that the chemical activation process is suitable to prepare granular activated carbon with very high surface area i.e. 2895 m2/g in short duration of time i.e. 1 to 2 hrs at lower temperature i.e. 750℃ from phenolic resins.