• Journal of the Korean Institute of Gas
• /
• v.20 no.4
• /
• pp.65-77
• /
• 2016

Modeling for complex reacting flow in Fischer-Tropsch reactor is one of the challenges in the field of Computational Fluid Dynamics (CFD). It is hard to derive each and every reaction rate for all chemical species because Fisher-Tropsch reaction produces many kinds of hydrocarbons which include lots of isomers. To overcome this problem, after analyzing the existing methodologies for reaction rate modeling, non-Anderson-Schulz-Flory methodology is selected to model the detailed reaction rates. In addition, the inside flow has feature of multi-phase flow, and the methodologies for modeling multi-phase flow depend on the interference between the phases, distribution of the dispersed phase, flow pattern, etc. However, existing studies have used a variety of inside flow modeling methodologies with no basis or rationale for the feasibility. Modeling inside flow based on the experimental observation of the flow would be the best way, however, with limited resources we infer the probable regime of inside flow based on conventional fluid dynamics theory; select the appropriate methodology of Mixture model; and perform systematic CFD modeling. The model presented in this study is validated through comparisons between experimental data and simulation results for 10 experimental conditions.

• Applied Chemistry for Engineering
• /
• v.5 no.5
• /
• pp.904-909
• /
• 1994

Cure kinetics of DGEBA(diglycidyl ether of bisphenol A)/MDA(4,4'-methylene dianiline)/GN(glutaronitrile) system with and without HQ(hydroquinone) as a catalyst was studied by Kissinger equation and Fractional life method. The activation energy of the system with HQ was somewhat lower and the pre-exponential factor of that was higher by about 30% than those of the system without HQ. As 1.25phr of HQ was added, reaction rates increased about 1.8 times.

• Journal of the Korean Chemical Society
• /
• v.16 no.2
• /
• pp.64-69
• /
• 1972

Nucleophilic reactivities of 1-and 2-phenethyl chlorides have been investigated MO-theoretically using the EHT method. It has been shown that results of population analysis are consistent with the experimental order of relative nucleophilic reactivities and furthermore the reversal of the reactivity order for the less reactive nucleophile, $I^-$, could also be explained satisfactorily.

• Journal of the Korean Chemical Society
• /
• v.34 no.1
• /
• pp.19-28
• /
• 1990

The rate of chlorine-exchange reaction of antimony trichloride with benzyl, $\alpha$-phenyl ethyl and diphenyl methyl chlorides in nitrobenzene have been determined. The results indicate that the chlorine-exchange reaction follows second-order kinetics with respect to antimony trichloride and first-order kinetics with respect to organic chlorides. Rate = $k_3[SbCl_3]^2$ [Org-Cl] The rate constants of chlorine-exchange of antimony trichloride with organic chloride increase in the following order of the organic chlorides. Benzyl chloride < $\alpha$-phenyl ethyl chloride < diphenyl methyl chloride The mechanism of the chlorine-exchange reactions has been proposed.

• Journal of the Korean Chemical Society
• /
• v.54 no.1
• /
• pp.125-130
• /
• 2010

In the present work, we have investigated the adsorption efficiency of carbon/iron oxide nanocomposite towards removal of hazardous brilliant green (BG) from aqueous solutions. Carbon/iron oxide nanocomposite was prepared by chemical precipitation and thermal treatment of carbon with ferric nitrate at $750^{\circ}C$. The resulting material was thoroughly characterized by TEM, XRD and TGA. The adsorption studies of BG onto nanocomposite were performed using kinetic and thermodynamic parameters. The adsorption kinetics shows that pseudo-second-order rate equation was fitted better than pseudo-first-order rate equation. The experimental data were analyzed by the Langmuir and Freundlich adsorption isotherms. Equilibrium data was fitted well to the Langmuir model with maximum monolayer adsorption capacity of 64.1 mg/g. The thermodynamic parameters were also deduced for the adsorption of BG onto nanocomposite and the adsorption was found to be spontaneous and endothermic.

• Journal of the Korean Chemical Society
• /
• v.32 no.3
• /
• pp.227-232
• /
• 1988

A kinetic study was made to determine the mechanism of the aquation of $cis-[Co(en)_2(NH_3)Cl]^{2+}\;in\;Hg^{2+}$ aqueous solution. The progress of reaction was followed UV/vis-spectrophotometrically by a measurement of the absorbance at a specific wave length (530nm) of $cis-[Co(en)_2(NH_3)Cl]^{2+}$ as a function of time. The experimental results have shown that the reaction rate is dependent upon the concentration of $Hg^{2+}$ that act as a catalyst. And it was found that the overall reaction proceed with second order, first order with respect to Co(III) complex and $Hg^{2+}$. Activation parameters, ${\Delta}H^{\neq}\;and\;{\Delta}S^{\neq}$, were obtained as 12.9 kcal/mol and -19.3 e.u., respectively. We have proposed a plausible reaction mechanism which is consistent with the observed rate equation.

• Korean Chemical Engineering Research
• /
• v.47 no.4
• /
• pp.410-417
• /
• 2009

Carbon dioxide was absorbed into GMA solution in a stirred flat cell using mesoporous catalyst Imidazole-CP-MS41, which was synthesized by CP-MCM41 with imidazole. Experiments were carried out at a batch-type absorber with different conditions, varying reaction temperature, concentration of GMA, solvent but maintaining 50 rpm of agitation speed and 2 g of catalyst. Absorption rate of $CO_2$ was used to obtain the kinetics based on the film theory using zwitterion mechanism with 2 elementary reaction and the kinetics were correlated with the solubility parameter of the solvents.

• Journal of the Korean Chemical Society
• /
• v.26 no.6
• /
• pp.407-413
• /
• 1982

The rate constants of the nucleophilic addition of cysteine to 3,4-methylenedioxyphenylmethylene malononitrile were determined by UV Spectrophotometry and a rate equation which can be applied over wide pH range was obtained. On the basis of rate equation, it may be concluded that the rate constants were dependent upon only the concentration of hydroxide ion above pH 9.0, however, below pH 6.0, the reaction were initiated by the addition of neutral cysteine molecule to carbon-carbon double bond and at pH 7.0~9.0, the addition of a neutral cysteine molecule and it's anion occurred competitively.

• Journal of the Korean Chemical Society
• /
• v.38 no.12
• /
• pp.921-923
• /
• 1994

• Journal of the Korean Chemical Society
• /
• v.41 no.5
• /
• pp.266-270
• /
• 1997