• Title/Summary/Keyword: Pyrolysis

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Theoretical Study on the Pyrolysis of Sulphonyl Oximes in the Gas Phase

  • Xue, Ying;Lee, Kyung-A;Kim, Chan-Kyung
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.853-858
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    • 2003
  • The reaction mechanism of the pyrolysis of sulphonyl oximes ($CH_3-C_6H_4-S(O)_2O-N=C(H)-C_6H_4Y$), in the gas phase is studied theoretically at HF/3-21G, ONIOM (B3LYP/6-31G**:HF/3-21G) and ONIOM (MP2/6- 31G**:HF/3-21G) levels. All the calculations show that the thermal decomposition of sulphonyl oximes is a concerted asynchronous process via a six-membered cyclic transition state. The activation energies (Ea) predicted by ONIOM (B3LYP/6-31G**: HF/3-21G) method are in good agreement with the experimental results for a series of tosyl arenecarboxaldoximes. Five para substituents, Y = $OCH_3$, $CH_3$, H, Cl, and $NO_2$, are employed to investigate the substituent effect on the elimination reaction. Linear Hammett correlations are obtained in all calculations in contrast to the experimental finding.

Preparation of Bi$_4$Ti$_3$O$_{12}$ Films by Dipping-Pyrolysis Process (도포 열분해법을 이용한 Bi$_4$Ti$_3$O$_{12}$제조에 관한 연구)

  • 황규석;이형민;김병훈
    • Journal of the Korean Ceramic Society
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    • v.35 no.9
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    • pp.1002-1005
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    • 1998
  • Bismuth titanate thin films were prepared on {{{{ { SrTiO}_{3 } }}(100) and Si(100) substrates by dipping-pyrolysis pro-cess using metal naphthenates as starting materials. crystallinity and in-phase alignment of the films were analyzed by X-ray diffraction $\theta$-2$\theta$ scans and $\beta$ scans (pole-figures) respectively. Highly c-axis-oriented {{{{ { { {Bi }_{4 }Ti }_{3 }O }_{12 } }} thin films with smooth surfaces were obtained after heat treatment at 75$0^{\circ}C$ on {{{{ { SrTiO}_{3 } }}(100) sub-strate while the films grown of Si(100) exhibited polycrstalline characteristics. C-axis oriented film show-ed an epitaxial relationship with the {{{{ { SrTiO}_{3 } }} substrate.

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Synthesis of TiO2 and BaTiO3 Powders by Ultrasonic Spray Pyrolysis Method (초음파 분무 열분해법에 의한 TiO2 및 BaTiO3 분말의 제조)

  • Kim, D.J.;Kim, H.
    • Journal of the Korean Ceramic Society
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    • v.26 no.5
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    • pp.691-697
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    • 1989
  • Fine TiO2 and BaTiO3 powders having spherical particles were synthesized by ultrasonic spray pyrolysis of alcoholic solution of metal alkoxide in an electric furnace heated at 400-90$0^{\circ}C$. Microstructure and composition of particles synthesized were observed by TEM and XRD respectively. Spectific surface area of powders synthesized was examined through BET specific surface area measurement. TEM observation revealed that the particle size did not change irrespective of pyrolysis temperature but decreased according to the increase of concentration and spherical particle was consisted of primary particles of about 0.02${\mu}{\textrm}{m}$. As for BaTiO3 powder, the ratio of Ti/Ba was 0.987 by EDX analysis.

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CdSe-sensitized Photoelectrochemical Solar Cell Prepared by Spray Pyrolysis Deposition Method

  • Im, Sang-Hyuk;Lee, Yong-Hui;Seok, Sang-Il
    • Journal of the Korean Electrochemical Society
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    • v.14 no.2
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    • pp.104-109
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    • 2011
  • We fabricated CdSe-sensitized photoelectrochemical solar cell by depositing CdSe nanoparticles on nanoporous $TiO_2$ (np-$TiO_2$) via spray pyrolysis deposition method. By adjusting the amount of CdSe-sensitizer deposited on np-$TiO_2$, we can fabricate an efficient CdSe-sensitized solar cell (${\eta}$ = 3.0% under 1 sun irradiation) in polysulfide liquid electrolyte.

Analysis of Cotton/Polyester Fabrics using Pyrolysis Gas Chromatograpy (열분해-GC에 의한 면/폴리에스터 혼방 직물의 분석)

  • 조미숙;김명덕;박성우;윤기준;남재도;이종훈;이영관
    • Polymer(Korea)
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    • v.27 no.3
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    • pp.271-274
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    • 2003
  • A pyrolysis gas-chromatographic method (Py-GC) was utilized for the identification as well as the content measurement of textile materials. Py-GC was applied to natural cotton fiber, synthetic polyester fiber, and their blended fabrics. The characteristic peaks originated from thermally decomposed products were observed, and the area of peak increased with the content of polyester. The products of pyrolized polyester were identified as benzoic acid terephthalic acid, and vinyl benzoic acid, which were characterized by mass spectrometry. This analytic method of offered a quantitative means to identify the content of cotton and polyester.

Parametric study on synthesis of carbon nanotubes by the vertical spray pyrolysis method

  • Park, Young-Soo;Huh, Mong-Young;Kang, Sin-Jae;Lee, Seung-Hee;An, Kay-Hyeok
    • Carbon letters
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    • v.12 no.2
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    • pp.102-106
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    • 2011
  • Carbon nanotubes (CNTs) have been synthesized by ferrocene-catalyzed pyrolysis of toluene. The influences of the experimental conditions on the morphology and microstructure of the product have been analyzed. To find the proper temperature for synthesis of CNTs, the experiment was performed in a temperature range from 800 to $1100^{\circ}C$. From content variation of ferrocene and thiophene as the catalyst, morphological change of carbon nanotubes has been observed. Also, the influence of the gas ratio of hydrogen and argon on the nanotube samples was analyzed by scanning electron microscopy and transmission electron microscopy.

Effects of Reaction Conditions on the Performance of Catalytic Pyrolysis of LDPE in a Semi-Batch Reactor (LDPE 반회분식 촉매열분해에서 조업조건이 반응 특성에 미치는 영향)

  • Na, Jeong-Geol;Leem, Chel-Hyen;Choi, Hwi-Kyoung;Chung, Soo-Hyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.79-82
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    • 2006
  • Fueled by ballooning oil prices, waste plastics are now regarded as being cheap and abundant renewable sources, removing their stigma of dirty wastes Catalytic pryolysis of plastics in liquid phase allows recovery of light fuel oil as well as green treatment of polymerics wastes, and therefore significant efforts have been devoted to this research field. In this study, catalytic Pyrolysis of LDPE was carl ied out in semi-batch reactor which equipped a unit of separation and recirculation. The effect of react ion conditions were examined by analyzing liquid oil yield and carbon number distribution of products

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The properties of ZnO/MgO films prepared by ultrasonic spray pyrolysis (초음파분무법으로 제조한 ZnO/MgO막의 특성)

  • Choi, Mu-Hee;Ma, Tae-Young
    • Journal of Sensor Science and Technology
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    • v.14 no.5
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    • pp.362-367
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    • 2005
  • ZnO films were deposited on MgO substrates (ZnO/MgO) by ultrasonic spray pyrolysis. Substrate temperature varied from $250^{\circ}C$ to $350^{\circ}C$. The crystallographic properties and surface morphologies of the ZnO/MgO films were studied by X-ray diffraction and scanning electron microscopy. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the substrate temperature and the annealing temperature. The ZnO/MgO films prepared at $350^{\circ}C$ showed the strongest Ultraviolet light emission peak at 18 K and 300 K among the films in this study. The annealing process increases the visible light emission, which is due to the increased oxygen vacancies.

Preparation of Porous Layered Carbon Using Magadiite Template (Magadiite 주형을 이용한 층상 카본의 합성)

  • Choe, Seok-Hyon;Jeong, Soon-Yong;Oh, Seong-Geun;Kwon, Oh-Yun
    • Applied Chemistry for Engineering
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    • v.16 no.3
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    • pp.408-412
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    • 2005
  • Porous layered carbon was prepared by interlayer pyrolysis of pyrolysis fuel oil (PFO) using magadiite template and successive dissolution of template. Particle morphology was plate type with d-spacing of approximately 0.7 nm and it had constant interlayer space. Specific surface area was $147{\sim}385m^2/g$ depending upon template type, mixing ratios and pyrolysis time.

An Equilibrium Analysis to Generate Syngas in the Pyrolysis and Gasification of Refuse Plastic Fuel (RPF 열분해 가스화시 합성가스 조성에 대한 화학평형 계산)

  • Kang, Pil-Sun;Bae, Su-Woo;Song, Soon-Ho;Hwang, Jung-Ho
    • Journal of the Korean Society of Combustion
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    • v.12 no.4
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    • pp.57-61
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    • 2007
  • The aim of this study is to find out the condition that generates maximum $H_2$ through the calculation of equilibrium model with conditions of pyrolysis gases of Refuse Plastic Fuel(RPF). This study deals with the computational simulation of a RPF gasification using an equilibrium model based on minimization of the Gibbs free energy. An equilibrium analysis was carried out to determine species composition of Syngas in RPF gasification and reactions to variation of temperature, $O_2/Fuel$ ratio and Steam/Fuel ratio. Calculated results shows that hydrocarbons in pyrolyzed gas are converted to synthesis gas which is formed on hydrogen and carbon monoxide.

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