• Title, Summary, Keyword: Phosphoric acid impregnation

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Selective Adsorption Properties of Carbonyl Compounds in Cigarette Mainstream Smoke by Hydrazine Impregnated Adsorbent (Hydrazine 첨착 흡착제에 의한 담배 주류연 중 카보닐 화합물의 선택 흡착 특성)

  • Park Jin-Won;Rhee Moon-Soo;Lee John-Tae;Hwang Keon-Joong;Hwang Taek-Sung
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.2
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    • pp.178-188
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    • 2005
  • To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine and dansylhydraznie impregnated adsorbents were prepared with perchloric acid or phosphoric acid as a accelerator in hydrazone formation reaction. The change of morphology of adsorbents in various of impregnator were investigated by SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were investigated. Amounts of impregnation was increased as increasing reaction time. The removal amount for vapor phase carbonyl compounds by 2,4-DNPH impregnated adsorbent was higher than that of dansylhydrazine impregnated adsorbent. The selectivity of 2,4-DNPH impregnated polyacrylic type adsorbent was superior to those of other adsorbents. This results indicated that the 2,4-DNPH impregnated polyacrylic adsorbent was applicable to cigarette filter material because of its fast reactivity and porosity.

Moringa Oleifera, A Biosorbent for Resorcinol Adsorption-Isotherm and Kinetic Studies

  • Kalavathy, M. Helen;Swaroop, G.;Padmini, E.;Lima Rose, Miranda
    • Carbon letters
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    • v.10 no.1
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    • pp.23-32
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    • 2009
  • The adsorption of phenolic compound resorcinol on activated carbons prepared from Moringa oleifera (Drumstick bark) has been investigated. Activated carbon was prepared by impregnating Moringa oleifera with 50% phosphoric acid in the ratio of 1:1 and 1:2(w/w), designated as MOAC1 and MOAC2. Equilibrium and isotherm studies were carried out. The influences of variables such as contact time, initial concentration of resorcinol, carbon dosage in the solution on percentage adsorption and adsorption capacity of the bark have been analysed. The equilibration time was found to be 4 h. Kinetics of resorcinol onto activated carbons was checked for pseudo first order and pseudo second order model. It was found that the adsorption of resorcinol follows pseudo second order kinetics for both MOAC1 and MOAC2. The isotherm data were correlated with isotherm models, namely Langmuir and Freundlich. Adsorption isotherms were satisfactorily fitted by both the Langmuir and Freundlich model for MOAC1 and MOAC2.

Preparation of Hydrazine Impregnated Adsorbents and Selective Adsorption Properties for Carbonyl Compounds in Cigarette Mainstream Smoke (Hydrazine 첨착 흡착제의 제조 및 담배 주류연 중 카보닐 화합물의 선택 흡착 특성)

  • Lee, John-Tae;Park, Jin-Won;Lee, Jeong-Min;Rhee, Moon-Soo;Hwang, Keon-Joong;Hwang, Taek-Sung
    • Polymer(Korea)
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    • v.30 no.3
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    • pp.210-216
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    • 2006
  • To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine (2,4-DNPH) and dansylhydrazine (DAH) impregnated adsorbents were prepared with perchloric acid or phosphoric acid as an accelerator in hydrazone formation reaction. Changes of molecular structure and morphology of adsorbents in various of impregnator were investigated by FTIR/ATR and SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were studied. Amounts of impregnation increased with increasing reaction time. The removal amount for vapor phase carbonyl compounds by 2,4-DNPH impregnated adsorbent was higher than that of dansylhydrazine impregnated adsorbent. The selectivity of 2,4-DNPH impregnated polyacrylic type adsorbent was superior to those of other adsorbents. This result indicates that the 2,4-DNPH impregnated polyacrylic adsorbent is applicable to cigarette filter material because of its fast reactivity and porosity.

Effects of Electrode and Matrix in the PAFC Performance (전극 및 메트릭스가 인산형 연료전지의 성능에 미치는 영향)

  • Kim, Dong-Jin;Song, Rak-Hyun;Lee, Byung-Rok;Kim, Chang-Soo;Shin, Dong-Ryul
    • Proceedings of the KIEE Conference
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    • pp.1873-1875
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    • 1999
  • The effects of electrode and matrix in the PAFC were investigated using AC-impedance spectroscopy. The performance of PAFC was determined by changing external electronic load. AC impedance measurement was carried out as functions of phosphoric acid impregnation temperature. operating temperature and matrix coating method using various cathodes ; 20%Pt/C, 20%Pt-Ni/C, 20%Pt-Co-Ni/C, 10%Pt-Fe-Co/C, and 20%Pt-Fe-Co/C From the analysis of measured impedance data, the interfacial resistance decreased with increasing operating temperature. and with decreasing impregnation temperature. As compared with the alloy catalysts, Pt catalyst showed a lower interfacial resistance. This consist with the cell performance.

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Removal of Pesticide (Endosulphan) from Water via Adsorption onto Activated Carbons Developed from Date Pits

  • Ashour, Sheikha.S.
    • Carbon letters
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    • v.8 no.2
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    • pp.101-107
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    • 2007
  • Activated carbons were prepared by impregnation of crushed clean date pits in concentrated solutions of phosphoric acid or zinc chloride followed by carbonization in absence of air at $600^{\circ}C$. Steam-activated carbon was prepared by gasifying $600^{\circ}C$-carbonization product at $950^{\circ}C$ to a burn-off = 50%. KOH- activated carbon was prepared by impregnating date pitscarbonization product obtained at $450^{\circ}C$ in concentrated KOH solution followed by carbonization at $840^{\circ}C$. Textural properties of these carbons were determined from nitrogen adsorption at $-196^{\circ}C$ and the chemistry of the carbon surface was investigated by determination and of the surface carbon-oxygen (C-O) groups using bases of variable strength and dilute HCl. The adsorption of endosulphan at $27^{\circ}C$ on all the carbons prepared was undertaken. Adsorption of this pesticide at 32 and $37^{\circ}C$ was also undertaken for steam-activated and KOH-activated carbons. Phosphoric acid-activated carbons and steamactivated carbons are mainly microporous and have high surface concentration of C-O groups of acidic nature. Steamactivated and KOH-activated carbons exhibited surface areas > 1000 $m^2/g$ and contain micro and non-micrpores. The adsorption of endosulphan was related to the surface area of non-micropores and was retarded by the high concentration of surface C-O groups. The thermodynamic properties indicated the feasibility of the adsorption process and the possible regeneration of the carbon for further use.

Electrochemical Characteristics of Pt/PEM/Pt-Ru MEA for Water Electrolysis (수전해용 Pt/PEM/Pt-Ru MEA의 전기화학적 특성)

  • Kweon, Oh-Hwan;Kim, Kyung-Eon;Jang, In-Young;Hwang, Yong-Koo;Chung, Jang-Hoon;Moon, Sang-Bong;Kang, An-Soo
    • Transactions of the Korean hydrogen and new energy society
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    • v.19 no.1
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    • pp.18-25
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    • 2008
  • The membrane electrode assembly(MEA) was prepared by a nonequilibrium impregnation- reduction (I-R) method. Nafion 117 and covalently cross-linked sulfonated polyetherether with tungsto- phosphoric acid (CL-SPEEK/TPA30) prepared by our laboratory, were chosen as polymer electrolyte membrane(PEM). $Pt(NH_3)_4Cl_2$, $RuCl_3$ and reducing agent $(NaBH_4)$ were used as electrocatalytic materials. Electrochemical activity surface area(ESA) and specific surface area(SSA) of Pt cathodic electrode with Nafion 117 were $22.48m^2/g$ and $23.50m^2/g$ respectively under the condition of 0.8 M $NaBH_4$. But Pt electrode prepared by CL-SPEEK/TPA30 membrane exhibited higher ESA $23.46m^2/g$ than that of Nafion 117. In case of Pt-Ru anodic electrode, the higher concentration of Ru was, the lower potential of oxygen reduction and region of hydrogen desorption was, and Pt-Ru electrode using 10 mM $RuCl_3$ showed best properties of SSA $34.09m^2/g$ with Nafion 117. In water electrolysis performance, the cell voltage of Pt/PEM/Pt-Ru MEA with Nafion 117 showed cell property of 1.75 V at $1A/cm^2$ and $80{\circ}C$. On the same condition, the cell voltage with CL-SPEEK/TPA30 was the best of 1.73 V at $1A/cm^2$.

Potential of Activated Carbon Derived from Local Common Reed in the Refining of Raw Cane Sugar

  • D-Abdullah, Ibrahim;Girgis, Badie S.;Tmerek, Yassin M.;Badawy, Elsaid H.
    • Carbon letters
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    • v.11 no.3
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    • pp.192-200
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    • 2010
  • Common reed (Fragmites australis), a local invasive grass, was investigated as a possible feedstock for the production of activated carbon. Dried crushed stems were subjected to impregnation with phosphoric acid (30, 40 and 50%) followed by pyrolysis at $400{\sim}500^{\circ}C$ with final washing and drying. Obtained carbons were characterized by determining: carbon yield, ash content, slurry pH, textural properties and capacity to remove color bodies from factory-grade sugar liquor. Produced carbons possessed surface area up to 700 $m^2/g$, total pore volumes up to 0.37 $cm^3/g$, and proved to be microporous in nature. Decolorization of hot sugar liquor at $80^{\circ}C$ showed degrees of color removal of 60 up to 77% from initial color of 1100~1300 ICU, at a carbon dose of 1.0 g/100 ml liquor. No correlation seems to hold between synthesis conditions and % R but depends on the degree of microporosity. A commercial activated carbon N showed a comparative better color removal capacity of 91%. Common reed proved to be a viable carbon precursor for production of good adsorbing carbon suitable for decolorization in the sugar industry, as well as in other environmental remediation processes.

Improvement of Platinum Particle Dispersion on Porous Electrode for Phosphoric Acid Fuel Cell (연료전지용 다공성전극에 있어서 백금촉매의 분산성개선)

  • Park, Jung-Il;Kim, Jo-Woong;Lee, Ju-Seong
    • Applied Chemistry for Engineering
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    • v.1 no.2
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    • pp.224-231
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    • 1990
  • To improve the dispersion of platinum catalyst, the effects of carbon black surface treatment, solvents, surfactants, and ultrasonic homogenizing were examined. Upon introducing the hydrophilic groups acting as an anchorage center of the catalyst on the surface of carbon black by oxidation, the migrating and growing of platinum particles(or ions) during reduction could be restricted. When mixed solvents, surfactants, or ultrasonic homogenizer were used to disperse catalysts on the carbon black, the dispersion of catalyst could be improved, due to the good permeation of chloroplatinic acid through the pore of carbon black. Among the impregnation methods, the method using ultrasonic homogenizer with mixed solvent was the most excellent. Using this method the particle sized could be minimized in less than $30A^{\circ}$ and distributed homogeneously.

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