• Title/Summary/Keyword: 화학반응식

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Gas and Temperature Distribution during MCFC Stack Operation (용융탄산염 연료전지 스택내에서의 온도/농도 분포 및 운전 특성)

  • 고준호;안교상;강병삼;김동형;임희천
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1998.05a
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    • pp.253-258
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    • 1998
  • 연료 전지 시스템에서의 스택은 화학 공장의 반응기에 해당한다. 화학 공장에서 반응 생성물의 생산성을 최적화하기 위해 반응기 해석이 매우 중요한 것과 마찬가지로, 연료 전지 스택의 특성을 해석하고 최적 조건으로 설계 및 운전하는 것은 필수적이다. 스택에서 전기를 생산하는 과정에서 중요한 두 가지 운전 변수는 기체의 조성과 온도이며, 이론적인 해석을 위해서는 유체의 이동시에 열전달 및 각 성분별 물질 수지식과 전기 화학 반응식이 사용될 수 있다.(중략)

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UV light transmittance in modified two-dimensional fluidized bed photocatalytic reactor (변형된 이차원 유동층 광촉매 반응기에서의 자외선 투과도 측정)

  • 임탁형;김상돈
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1999.11a
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    • pp.67-70
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    • 1999
  • 최근에 들어서 태양에너지의 화학적 에너지로의 변환에 대한 연구는 에너지 부족에 대한 대안으로서 각광을 받고 있는 분야이다. 이런 관심을 바탕으로 한 다양한 연구는 연속식 또는 회분식 반응기를 이용한 불균일계 촉매를 이용함으로써 진행되고 있고, 특히 기-액, 기-고 그리고 기-액-고상 반응기를 응용하는 광촉매 반응에 관심이 증폭되고 있다. 그리고 광촉매 반응이 실제 산업계에서 활용되기 전에 먼저 불균일계 광촉매 반응기의 설계기준에 대한 연구가 선행되어야 하며 실제 산업적인 응용측면에서도 광촉매 반응의 충분한 이용가능성에 관심이 이루어져야 한다.(중략)

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Application of Pseudo Molecular Complexes (II). A New Mechanism for Aromatic Substitution (유사분자 착물의 응용 (제 2 보). 새로운 방향족 치환반응 기구)

  • Park Byung-Kak
    • Journal of the Korean Chemical Society
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    • v.19 no.3
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    • pp.179-185
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    • 1975
  • A new mechanism is proposed for aromatic substitution, involving the formation of pseudo molecular complexes at the transition state. It accounts for the addition reactions of aromatic compounds with double bond reagents such as ozone, somium tetraoxide and carbene as well as all of the features of electrophilic substitution reactions. The pseudo molecular complex has been proved to be formed by quantum-chemical considerations using the simple Huckel method.

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Application of the Pervaporation for Separation of $H_2O$/HI/$I_2$-Component System in IS Process for Thermochemical Hydrogen Production (열화학적 수소제조 IS 프로세스에서 $H_2O$/HI/$I_2$ 3성분계 분리를 위한 투과증발 응용)

  • 최호상;황갑진;소관훈
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05b
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    • pp.106-109
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    • 2004
  • 원자력의 고온가스로(HTGR)의 열원에서 약 1,00$0^{\circ}C$의 열을 이용하여 물을 분해하는 열화학적 수소제조 IS 프로세스는 다음과 같은 3단계 화학반응식에 의해 수소를 제조한다. 이들 화학반응의 수행과정을 반응온도와 공정에 따라 도식화하면 Fig. 1과 같은 3가지 공정으로 구성된다.(중략)

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Electrosynthesis of n-PFOSF with Potential Operation (정전위법에 의한 n-PFOSF 합성)

  • Lee, Jongil;Tae, Beomseok
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.473-480
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    • 1996
  • Synthesis of n-perfluorooctanesulfonyl fluoride(n-PFOSF), which is valuable precursor perfluoro-chemicals, was studied by electrochemical fluorination(ECF). Of prime concern was to investigate the cyclic voltamograms of Ni electrode in anhydrous hydrogen fluoride(AHF) with and without the reactants and to measure fluorine evolution potential. In a batch cell, chronoampherometric electrolysis and various chemical analysis such as GC, GC/MS and IR were used to understand the amphere change of electrode and the reaction paths. Fluorine equilibrium potential was found to be about 2.8V(vs. $Cu/CuF_2$) from the cyclic voltammograms and decay curves of anode potential in AHF. In batch processes, the ECF proceeded in two distinguished steps. The first step proceeded electrochemically and the second one chemically. Under 7V(vs. $Cu/CuF_2$), amount of crude products was proportional to the applied anode potential. Above 7V(vs. $Cu/CuF_2$), it had a hundred percentage with weight ratio of reactants and productivity of PFOSF was almost constant.

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The Kinetics and Mechanism of Nucleophilic Addition of n-Butylmercaptan to Ethylacrylate (Ethylacrylate에 대한 n-Butylmercaptan의 친핵성 첨가반응에 관한 연구)

  • Kwon Dong-Sook;Kim Tae-Rin
    • Journal of the Korean Chemical Society
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    • v.16 no.4
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    • pp.232-240
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    • 1972
  • The rate constants for the addition reaction of n-butylmercaptan to ethylacrylate have been measured by iodometry and for the proposed reaction mechanism a rate equation which can be applied over wide pH range was derived. From this rate equation, one may conclude that the reaction is started by addition of n-butylmercaptan molecule below pH 4. However, above pH 7, this addition reaction is proceeded by the n-butylmercaptide ions. At pH 4-7, the complex addition reaction mechanism can also be revealed by this rate equation.

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Computational Study of Intermetallic Reaction Propagation in Nanoscale Boron/Titanium Metallic Multilayers (보론/티타늄 나노박막다층 내 이종금속간 화학반응 전파특성 해석연구)

  • Kim, Kyoungjin;Park, Joong-Youn
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.3
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    • pp.10-17
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    • 2017
  • The analytical modeling has been established on the self-propagation of intermetallic reaction in the spanwise direction of highly reactive boron and titanium nanoscale multilayers. Assuming that the reaction obeys Arrhenius kinetics, two-dimensional computations are carried out for heat and atomic species diffusion with exothermic reaction model in order to simulate the self-propagation of intermetallic reaction. The effects of bimetallic layer thickness and thickness ratio on the reaction propagation speed are tested and discussed in addition to the assessment of pre-mixing zone effects.

Solvolysis of 3-Chloro-1,2-benzisothiazole-1,1-dioxide (pseudosaccharin chloride (3-Chloro-1,2-benzisothiazole-1,1-dioxide (pseudosaccharin chloride)의 가용매 분해반응)

  • In-Sun Koo;Jeong-Ja Kim;Yong-Jin Yoon;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.30 no.3
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    • pp.296-300
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    • 1986
  • The pseudo-first order rate constants have been obtained for the solvolysis of pseudo-saccharinechloride in MeOH-$H_2O$, EtOH-$H_2O$, MeOH-MeCN and MeOH-$(Me)_2$CO solvents mixtures at various temperatures. Values of n and m in the Kivinen and Grunwald-Winstein plots, respectively, have been determined and the Taft's solvatochromic parameters were obtained; based on these solvent effect parameters as well as on the activation parameters it was concluded that reaction proceeds via an $S_N2$ mechanism.

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The Kinetics Study of Ozone with Sulfur Dioxide in the Gas Phase (기체 상태에서의 오존과 아황산가스의 반응연구)

  • Young Sik Kwon
    • Journal of the Korean Chemical Society
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    • v.35 no.2
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    • pp.111-118
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    • 1991
  • The kinetic of the gas phase reactions of ozone(0.5 torr) with sulfur dioxide was studied. The SO2 reaction was conducted in the 7∼22 torr range at 90∼155$^{\circ}$C. The reaction rate was faster than the reaction rate of O$_3$ in the presence of CO$_2$ alone. The reaction of O$_3$ with SO$_2$ follows the rate law: -d(O$_3)/dt=k_0(SO_2)(M)(O_3)+2k _1(SO_2)(O_3$). The first term of this rate law arises from a third order molecular reaction predominating in the lower temperature range and gave a rate constant k$_0$ = (9.35 $\pm$ 8.6) ${\times}$ 10$^9$e$^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The second term of the above rate law derived from a second order thermal decomposition reaction which was the major part of the reaction and gave a rate constant k$_0 =(9.35{\pm}8.6){\times}10^9e^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The overall reaction proceeds with kinetics of complex order composed mainly of second order and third order components.

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Kinetics and Mechanism of the Hydrolysis of N-(p-Nitrophenyl)-benzohydrazonyl Azide Derivatives (N-(p-니트로페닐)-벤조히드라조닐아지드 유도체의 가수분해 반응메카니즘과 그의 반응속도론적 연구)

  • Nack-Do Sung;Ki-Sung Kwon;Tae-Rin Kim
    • Journal of the Korean Chemical Society
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    • v.22 no.3
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    • pp.150-157
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    • 1978
  • The rate constants for the hydrolysis of the derivatives of N-(p-nitrophenyl)-benzohydrazonyl azide (p-$CH_3,\;p-CH_3O,\;p-NO_2$, p-Cl, p-Br) have been determined by UV spectrophotometry in 50% dioxane-water at $25^{\cicr}C$ and a rate equation which can be applied over wide pH range was obtained. Below pH 5, the rate of hydrolysis of hydrazonyl azides is accelerated by electron-donating group ($\rho$ = -0.47), whereas at the pH values greater than 7, the $\rho$-value is 0.68. The effect of salt, solvent, substituent and azide ion on the rate of hydrolysis are rationalized in terms of $S_N1$ and $S_N2$ mechanism; below pH 5, the hydrolysis proceed through $S_N1$, however, above pH 7, the hydrolysis is started by the attack of hydroxide ion and in the range of pH 5∼7, these two reactions occur competitively.

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