• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.956-960
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• 1998

Cu-Zn and Cu-Zn-Ti catalysts for the steam reforming of methanol were prepared. This reaction was carried out at atmospheric pressure, $250^{\circ}C$, steam/methanol molar ratio 1.5, and contact time 0.1 g-cat.hr/mL-feed. In case of the catalyst with 3 mol% of $TiO_2$, the activity was superior to that of catalysts without $TiO_2$. The reaction products were mainly hydrogen and carbon dioxide. It was found that catalytic activity was not related to specific surface area but affected by metallic copper area which was measured by $N_2O$ decomposition and increased with the addition of $TiO_2$ content. XPS and XRD showed that the oxidation state of zinc was not changed during reaction, but oxidation states of copper existed in Cu(0) or Cu(I).

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.311-316
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• 2014

Effects of operating parameters such as activated carbon dose and pH on the phenol oxidation in ozone-activated carbon hybrid process were investigated through a kinetic study. Activated carbon enhanced the self-decomposition of ozone, generating $OH{\cdot}$, thus promoting phenol degradation. The pseudo-first order rate constants of phenol degradation increased and half-life of phenol decreased with activated carbon dose. The increase of pH enhanced $OH{\cdot}$ generation through chain reactions initiated by $OH^-$, therefore increasing the phenol degradation rate. TOC removal efficiency increased about 3.2 times by adding activated carbon in ozonation process.

• Advances in Energy Research
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• v.1 no.1
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• pp.1-12
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• 2013

In this work, we present the catalytic dehydrogenation of hydrazine borane $N_2H_4BH_3$ (HB) using supported nickel catalysts at $50^{\circ}C$. In the presence of monometallic nickel catalysts, the dehydrogenation of HB is a one-step reaction consisting of the hydrolysis of the $BH_3$ group only. The challenge is to activate nickel to make it reactive towards the $N_2H_4$ moiety of HB. A set of 52 catalysts were prepared by using 2 supports ($Al_2O_3$ and $TiO_2$), 5 nickel precursors and 3 preparation methods. For the first time, we show that the supported nickel catalysts are able to dehydrogenate the $NH_3$ moiety of HB. In our experimental conditions, the best results were obtained with 20 wt% Ni-$Al_2O_3$ and 20 wt% Ni-$TiO_2$, with ca. 190 mL $H_2+N_2$ generated over a total theoretical volume of 283 mL, suggesting $H_2$ selectivity of 37 and 32%, respectively. Both catalysts were then characterized by EDX, XPS, and XRD. Our achievement is the first step forward and opens new perspectives for developing catalysts for the total dehydrogenation of HB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.922-926
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• 2002

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks as heating temperature for NOx removal, we measure NO, $NO_2$ concentration as increasing temperature of sludge pellets and applying high voltage to sludge pellets in a quartz-glass reactor at the same time. NO initial concentration is 100ppm balanced with air gas in a mixing chamber. The gas flow is 5[l/min] and the heating temperature of sludge pellets in a quartz-glass reactor is adjusted from $200[^{\circ}C]$ $400[^{\circ}C]$ to investigate the effect of sludge pellets for removal NOx$(NO+NO_2)$ as increasing temperature. $BaTiO_3$ pellets is filled in a packed-bed reactor for corona discharge to measure how much NOx$(NO+NO_2)$ is removed after generating $NO_2$ from the packed-bed reactor. AC[60Hz] voltage is supplied to the reactor for discharge. In the result, $NO_2$ concentration is decreased by sludge pellets without heating temperature for sludge pellets in case of sludge pellets done heat treatment, however NO concentration is almost the same to be compared NO initial concentration. As increasing heating temperature for sludge pellets, $NO_2$ adsorbed on the sludge surface done heat treatment is converted to NO by the thermal energy, so NO concentration is extremely increased by reduction decomposition of $NO_2$. Finally, We think the sludge is possible to use for reduction catalysts, however we need to study more about the possibility and endurance of sludge as catalysts for NOx removal.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.685-693
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• 1997

We have studied the reforming of carbon dioxide with methane over various supported nickel catalysts. The nickel supported on natural zeolite showed the highest activity and the nickel on acidic support showed higher activity and slow deactivation compared to nickel on basic support. The activity of nickel on natural zeolite increased with increasing loading ratio and showed almost constant activity above 10wt.% loading of nickel. The conversion and yield of products were affected by the mole ratio of reactants and the highest yields of CO and $H_2$ were obtained at $CH_4/CO_2=1$. The deactivation of catalyst was caused by deposition of coke which was formed by the decomposition of methane. The shape of coke was shown to be whisker tripe carbon, and it brought out the slow deactivation of catalyst.

• Journal of the Korean Chemical Society
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• v.16 no.5
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• pp.271-283
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• 1972

The rate Constants and energies of activation for the Combustion reaction of Korean anthracites have obtained by DTA method using the following rate equation derived by authors. $K=\frac{C_3{\cdot}W_0}{{\Delta}H{\cdot}{\Delta}C{\cdot}M{\cdot}S_A}(\frac{dy}{dt}+A(y-y_3))$ The anthracites of various ranks were treated at the different temperatures in the furnace. The probable combustion reaction mechanisms have discussed with the results obtained by the X-ray diffraction method, IR spectroscophic analysis, and gas chromatography. By the intensity of d(002) Values, it was confirmed that a parts of the amorphous carbon was converted to graphite form by heat treatment. The appreciable amounts of CO gas were expelled in the combustion process and it appeared that a little amount of the gas came from the catalytic decomposition of anthracites, The functional groups such as -OH, -SH, -NH, $-CH_2-CH_3,$ -CO, -COC-. and polycondensed aromatic rings in anthracites have observed by IR spectrophotometric analysis.

• Polymer(Korea)
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• v.29 no.4
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• pp.338-343
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• 2005

The thermal degradation of ABS/PC/triphenyl phosphate compounds in the presence of transition metal chloride catalysts has been studied by thermogravimetric analysis (TGA). The reaction of transition metal chloride catalysts (cobalt chloride, ferric chloride, nickel chloride and zinc chloride) and ABS/PC/triphenyl phosphate compounds has been found to occur during the thermal degradation of the compounds. In a nitrogen atmosphere, char formation is observed, and $3\~13\%$of the reaction product is non-volatile at $600^{circ}$. The resulting enhancement of char formation in a nitrogen atmosphere has been explained as a catalytic crosslinking effect of transition metal chloride catalysts. On the other hand, transition metal chloride catalyzed char formation of ABS/PC/triphenyl phosphate compounds in air was unsuccessful due to the oxidative degradation of the char at a higher temperature.

• Macromolecular Research
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• v.10 no.5
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• pp.253-258
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• 2002

The multi-wall carbon nanotubes (MWNTs) with graphite crystal structure were synthesized by the catalytic decomposition of a ferrocene-xylene mixture in a quartz tube reactor to use as the conductive filler in the binary polymer matrix composed of poly(vinylidene fluoride) (PVdF) and poly(vinyl pyrrolidone) (PVP) for the EMI (electromagnetic interference) shielding applications. The yield of MWNTS was significantly dependent on the reaction temperature and the mole ratio of ferrocene to xylene, approaching to the maximum at 800 $^{\circ}C$ and 0.065 mole ratio. The electrical conductivity of the MWNTs-filled PVdF/PVP composite proportionally depended on the mass ratio of MWNTs to the binary polymer matrix, enhancing significantly from 0.56 to 26.7 S/cm with the raise of the mass ratio of MWNTs from 0.1 to 0.4. Based on the higher electrical conductivity and better EMI shielding effectiveness than the carbon nanofibers (CNFs)-filled coating materials, the MWNTs-filled binary polymer matrix showed a prospective possibility to apply to the EMI shielding materials. Moreover, the good adhesive strength confirmed that the binary polymer matrix could be used for improving the plastic properties of the EMI shielding materials.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.68-78
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• 2006

In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.496-501
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• 2005

The thermal degradation of ABS in the presence of iron-based metal catalysts has been studied by thermogravimetric analysis (TGA). The reaction of iron-based metal catalysts (ferric nitrate nonahydrate, ammonium ferric sulfate dodecahydrate, iron sulfate hydrate, ammonium ferric oxalate, iron(II) acetate, iron(II) acetylacetonate and ferric chloride) with ABS has been found to occur during the thermal degradation of ABS. In a nitrogen atmosphere, char formation was observed, and at $600^{\circ}C$ approximately 3~23 wt% of the reaction product was non-volatile char. The resulting enhancement of char formation in a nitrogen atmosphere has been primarily due to the catalytic crosslinking effect of iron-based metal catalysts. On the other hand, char formation of ABS in air at high temperature by iron-based metal catalyst was unsuccessful due to the oxidative degradation of the char.