• Title/Summary/Keyword: iodine adsorption

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Changes of Adsorption Properties of Woody Charcoals Prepared by Different Carbonizing Temperature (탄화온도 차이에 의한 목질탄화물의 흡착성 변화)

  • Jo, Tae-Su;Ahn, Byoung-Jun;Choi, Don-Ha
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.3 s.131
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    • pp.45-52
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    • 2005
  • This research was performed to evaluate adsorption behavior of woody charcoals obtained from wood powder, fiber and bark of spruce (Abies sibirica Ledeb). The wood materials were carbonized at various temperatures for 1 hour using experimental rotary kiln without any inert gas. The adsorption capacity of iodine and toluene, specific surface area and removal efficiency of acetic acid and ammonia gas of those charcoals were measured. The higher was the temperature for carbonization, the lower yields of charcoals were. Ash content of bark charcoal was higher than that of wood powder charcoal or fiber charcoal. Elemental analysis of woody charcoal revealed that the content of carbon was gradually lincreased as carbonization temperature was higher. When carbonization temperature was higher, adsorption capacity of woody charcoals for iodine was much improved. Wood powder charcoal and fiber charcoal were more effective for iodine adsorption rather than bark charcoal. Capacity of toluene adsorption was the highest in the charcoal of $600^{\circ}C$. Charcoals produced at high temperature efficiently removed acetic acid gas, while charcoals carbonized at low temperature such as $400^{\circ}C$ were proper to remove ammonia gas. This difference may be explained that the acidity of charcoals depends on the carbonization temperature: charcoals of low temperature indicate acidic property, while those of high temperature turned to alkaline.

Production of Activated Carbon from Bamboo by Gas Activation Method (기상 활성화법에 의한 대나무 활성탄 제조)

  • 조광주;박영철
    • 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.

Preparation of Spherical Activated Carbon and Their Physicochemical Properties

  • Oh, Won-Chun;Kim, Jong-Gyu;Kim, Hyuk;Chen, Ming-Liang;Zhang, Feng-Jun;Zhang, Kan;Meng, Ze-Da
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.568-573
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    • 2009
  • In this study, we used coal based activated carbons as starting material and phenolic resin (PR) as a bonding agent to prepare spherical shaped activated carbons. The textural properties of SAC were characterized by BET surface area, XRD, SEM, iodine adsorption, strength intensity and pressure drop. According to the results, the spherical activated carbon prepared with activated carbon and PR at a ratio of 60:40 was found to have the best formation of spherical shape, which was found in sample SAC40. After activation, SAC40 has high BET surface area, iodine adsorption capability and strength value, and lowest pressure drop.

Adsorptivities and Particle Surface Properties of the Activated Carbon Made from Rice-chaff (왕겨로부터 제조한 활성탄의 입자표면특성과 흡착력)

  • Lee, Dong-Sun;Lee, Myung-Hwan;Lee, Yoon-Joong;Ahn, Moon-Gyu
    • YAKHAK HOEJI
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    • v.32 no.3
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    • pp.187-193
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    • 1988
  • An activated carbon which showed big adsorption capacities of iodine, potassium permanganate and phenol was prepared from the Korean ricechaff. By scanning electron micrographs and IR spectra, it was observed that the organic components in the rice-chaff were decomposed to carbon dioxide and vapor by the pyrolysis and the activation, that activated carbon particles had carbon-carbon structures with a lot of microporosity. The adsorption capacities of iodine, potassium permanganate and phenol were determined. The adsorption isotherm of phenol was well fitted in Freundlich's equation.

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Adsorption Characteristics of Activated Carbon Prepared From Waste Citrus Peels by NaOH Activation (NaOH 활성화법으로 제조한 폐감귤박 활성탄의 흡착특성)

  • Kang, Kyung-Ho;Kam, Sang-Kyu;Lee, Song-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.16 no.11
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    • pp.1279-1285
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    • 2007
  • The activated carbon was prepared from waste citrus peels using NaOH. With the increase of NaOH ratio, iodine adsorptivity and specific surface area of the activated carbon prepared were increased, but activation yield was decreased. The optimal condition of activation was at 300% NaOH and $700^{\circ}C$ for 1.5 hr. For the activated carbon produced under optimal condition, iodine adsorptivity was 1,006 mg/g, specific surface area was $1,356 m^2/g$, and average pore diameter was $20{\sim}25{\AA}$. From the adsorption experiment for benzene vapor in fixed bed reactor, it was found that the adsorption capacity of activated carbon prepared from waste citrus peel was higher than that of activated carbon purchased from Calgon company. This result implied that the activated carbon prepared from waste citrus peel could be used for gas phase adsorption.

Additional Effect of Zeolite Based on Bactericidal Activated Carbon Spheres with Enhanced Adsorption Effect and Higher Ignition Temperature

  • Zhu, Lei;Ye, Shu;Asghar, Ali;Bang, Seong-Ho;Oh, Won-Chun
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.68-74
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    • 2016
  • In this study, the fabrication of zeolite combined activated carbon spherical samples was carried out as follows. Briefly, ZSM-5 zeolite and activated carbon were composed as main absorbent materials; by controlling the weight percentage of zeolite and binder materials, a series of spherical samples (AZP 4, 6, 8) were prepared. These spherical samples were characterized by BET, XRD, SEM, EDX, and pressure drop; benzene and iodine adsorption tests, bactericidal effect test, and ignition temperature test were also performed. The adsorption capability was found to depend on the BET surface area; the spherical samples AZP6 with high BET surface area of $1011m^2/g$ not only exhibited excellent removal effects for benzene (24.9%) and iodine (920mg/g) but also a good bactericidal effect. The enhanced ignition temperature may be attributed to the homogeneous dispersion conditions and the proper weight percentage ratio between zeolite and activated carbon.

Preparation of PAN-based Activated Carbon Fibers by Physical Activation (물리적 활성화에 의한 PAN계 활성탄소섬유의 제조)

  • 임연수;김기원;정승훈;김기덕;정윤중
    • Journal of the Korean Ceramic Society
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    • v.36 no.10
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    • pp.1016-1021
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    • 1999
  • In this study activated carbon fibers were prepared from PAN-based carbon fibers by physical activation with steam or carbon dioxide. The variations in specific surface area amount of iodine adsorption and pore size distribution of the activated carbon fibers after the activation process were discussed. in steam activation BET surface area of about 1019 m2/g was obtained after 77% burn-off while carbn dioxide activation produced ACF with 694m2/g of BET surface area after 52% burn-off. However carbon dioxide activation produced at a similar degree of activation higher micropore volume(0.37 cc/g) and amount of iodine adsorption (1589mg/g) than steam activation. Nitrogen adsorption isotherms for (PAN based activated carbon fibers that prepared by physical activation were of type I in the Brunauer-Deming-Deming-Teller classification

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Adsorption Characteristics of H2S on Adsorbent Made by Sewage Sludge in Fixed Bed Adsorption Column (하수슬러지를 활용하여 제조한 흡착제의 고정흡착층에서의 H2S 흡착특성)

  • Park, Chun-Dong;Youn, Ju-Young;Park, Yeong-Seong
    • Korean Chemical Engineering Research
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    • v.50 no.4
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    • pp.718-722
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    • 2012
  • $H_2S$ adsorption characteristics of adsorbent made by sewage sludge were investigated. For analyses of the manufactured adsorbent, various methods such as Iodine adsorptivity, scanning electron microscope (SEM), and measurements of BET surface area and pore volume were adopted. As the major adsorption characteristic, breakthrough curve was measured by using a continuous fixed bed adsorption column for operating variables such as adsorption temperature ($25{\sim}45^{\circ}C$), aspect ratio (L/D)(3~9), gas flow rate (0.1~2.0 liter/min) and $H_2S$ gas concentration (50~200 ppm). The experimental result showed that the carbonization and activation of sewage sludge are very important for the improvement in $H_2S$ adsorption capacity.

Studies on the Syndiotactic Poly(vinyl alcohol) Polarizing Film -Preparation of Low Molecular Weight Syndiotactic Poly(vinyl alcohol)/Iodine Complex Film and Its Characterization- (교대배열 폴리비닐알코올 편광필름에 관한 연구 -저분자량 교대배열 폴리비닐알코올/요오드 복합체 필름의 제조와 특성 해석-)

  • 류원석;염정현;최진현;지병철;노태환
    • Polymer(Korea)
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    • v.24 no.5
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    • pp.713-720
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    • 2000
  • A polymer/iodine complex film was prepared using syndiotactic poly(vinyl alcohol) (s-PVA) with number-average degree of polymerization of 900 and syndiotactic diad content of 63.1%. In comparison with atactic-PVA/iodine films, degree of polarization of the s-PVA/iodine film was improved up to over 99% although a lower transmittance was obtained. By soaking in iodine/potassium iodide aqueous solution of a lower iodine concentration and subsequent drawing by 4 times, s-PVA/iodine film of a higher transmittance and degree of polarization was produced. The degree of iodine desorption of the s-PVA/iodine film in water were very low. The crystallinity and the d-spacing and crystal size of (100) plane increased at the early stage of soaking time, however, remained constant or decreased slightly with increasing soaking time. In consequence, s-PVA/iodine complex formation took place mainly inside crystal region at the initial stage of soaking time, whereas it occurred outside crystal region or physical adsorption of iodine dominated after sufficient soaking.

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Capture of Volatile Organic Iodine Species Using Mordenites

  • Tejaswini Vaidya;John P. Stanford;Nicolene van Rooyen;Krishnan Raja;Vivek Utgikar;Piyush Sabharwall
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.2
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    • pp.205-224
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    • 2023
  • The emission of off-gas streams from used fuel recycling is a concern in nuclear energy usage as they contain radioactive compounds, such as, 3H, 14C, 85Kr, 131I, and 129I that can be harmful to human health and environment. Radioactive iodine, 129I, is particularly troublesome as it has a half-life of more than 15 million years and is prone to accumulate in human thyroid glands. Organic iodides are hazardous even at very low concentrations, and hence the capture of 129I is extremely important. Dynamic adsorption experiments were conducted to determine the efficiency of sodium mordenite, partially exchanged silver mordenite, and fully exchanged silver mordenite for the removal of methyl iodide present at parts per billion concentrations in a simulated off-gas stream. Kinetic analysis of the system was conducted incorporating the effects of diffusion and mass transfer. The possible reaction mechanism is postulated and the order of the reaction and the values of the rate constants were determined from the experimental data. Adsorbent characterization is performed to investigate the nature of the adsorbent before and after iodine loading. This paper will offer a comprehensive understanding of the methyl iodide behavior when in contact with the mordenites.