• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.388-393
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• 1999

Polyurethane foams are polymeric material with repeating groups of urethane and urea. When these are heated with ethylene glycol and K acetate catalyst at $200^{\circ}C$, the transesterification of them leads to soluble products. The mechanisms of the reaction were investigated from the molecular weight and the component distributions of the products by GPC and IR analysis. The degradation of the urethane groups was faster than that of urea groups in transesterification reaction. K acetate catalyst accelerated the rate of the transesterification because it had a high ionization tendency. Each reaction, using K or Sr acetate as a catalyst, progressed in the same reaction path but yielded different compositions in products because of the difference of the reaction rate.

• Journal of Hydrogen and New Energy
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• v.18 no.3
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• pp.309-316
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• 2007

조합 및 고속탐색 실험 기법을 촉매 성분의 선정에 활용하였다. 소형 연료전지 작동을 위한 수소 생산에 가장 적합한 것으로 알려진 메탄을 산화 분해용 촉매의 특성을 적외선 화상 및 병렬형 반응 시스템으로 조사하였다. 반응의 모델을 먼저 제시하고 이를 근거로 Cu-Zn-Pd계 촉매를 선정하였다. 먼저 적외선 화상을 이용한 스크리닝을 위해서는 발열 효과라는 촉매 활성의 간접적인 현상을 보여줄 수 있는 적외선 민감 카메라를 이용하여 한 번에 50개의 시료 측정이 가능한 촉매 시료 배열을 설계하였다. 적외선 화상 결과로 높은 활성을 보이는 촉매 시료를 선정한 다음, 병렬형 반응 시스템과 단일 흐름 고정층 반응 시스템으로 선정된 촉매의 활성 특성을 조사 확인하였다. 본 연구에서 제시한 것과 같은 접근 방법으로 지속적으로 얻어진 결과를 반영하여 최적의 활성을 보이는 촉매 성분을 단기간에 찾아내고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.373-376
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• 2010

The characteristics of thermal-resistance catalyst for $N_2O$ propellant decomposition were studied in the present study. Si was added to the $Al_2O_3$ support to stabilize its surface area at high temperature (> $1000^{\circ}C$). Ru was used as a catalyst for $N_2O$ decomposition. The prepared catalysts were characterized using SEM, EDS and XRD analysis, and $N_2O$ conversion was measured as reaction temperatures. The Ru/$Al_2O_3$-Si catalyst showed better performance than Ru/$Al_2O_3$ catalyst.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.269-272
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• 2009

Catalytic decomposition of nitrous oxide was investigated experimentally. Two noble metal catalyst (Pt, Ir) were chosen to decompose nitrous oxide. Each catalyst was tested with different chamber pressure and preheating temperature. Ir decomposed $N_2O$ at lower temperature ($230^{\circ}C$) and suitable for $N_2O$ decomposition. In addition, the minimum required preheating temperature decreased as the chamber pressure increased. However, deactivation of Ir catalyst was observed during the experiments.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.303-309
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• 2009

The effects of zeolite type catalysts addition on the thermal decomposition of low density polyethylene(LDPE) and ethylene vinyl acetate(EVA) resin have been studied in a thermal analyzer(TGA, DSC) and a small batch reactor. The zeolite type catalysts tested were natural zeolite, FCC catalyst, used FCC catalyst, and catalyst A. As the results of TGA experiments, addition of antifogging-agent decreased the pyrolysis point to $250^{\circ}C$, but addition of longevity-agent and clay reduced the pyrolysis rate in EVA resin. Addition of the zeolite type catalysts in the LDPE resin increased the pyrolysis rate in the order of catalyst A > used FCC catalyst > natural zeolite > LDPE resin. Addition of the zeolite type catalysts in the EVA resin increased the pyrolysis rate in the order of used FCC catalyst > natural zeolite > catalyst A > EVA resin. In the DSC experiments for LDPE resin, addition of zeolite type catalysts decreased the melting point and the heat of pyrolysis reaction in the order of catalyst A > used FCC catalyst > natural zeolite> LDPE resin. In the batch system experiments, the mixing of natural zeolite enhanced the yield of liquid fuel oil.

• Analytical Science and Technology
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• v.23 no.4
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• pp.383-388
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• 2010

Catalytic dissociation reaction was studied in order to transform waste plastics to oil by using noble metal supported catalysts. XRD, SEM, and GC/MSD analysis were performed to find the crystalline structure and shape, and product distribution. Generally, dissociation reaction occurs at low temperature compared to pyrolysis. Dissociation reaction has advantage of gasoline yield with respect to pyrolysis which products mainly $C_1\simC_4$. The result of dissociation reaction, gasoline was obtained much as a product. $C_5\simC_{11}$ compounds were produced as a gasoline product on Pt-zeolite among noble metal catalysts at $340^{\circ}C$. The conversion of dissociation reaction of waste plastics on the prepared catalyst was above 70% over $340^{\circ}C$.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.442-448
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• 2012

The effects of zeolite-type catalysts addition on the thermal decomposition of the PP resin have been studied in a thermal analyzer, a Pyrolyser GC-mass, and a small batch reactor. The zeolite type catalysts tested were natural zeolite, used FCC catalyst, and ZSM-5. As the results of TGA experiments, the pyrolysis starting temperature for PP varied in the range of $330{\sim}360^{\circ}C$ according to the heating rate. Addition of the zeolite type catalysts in the PP resin increased the pyrolysis rate in the order of used FCC catalyst> natural zeolite> ZSM-5 > PP resin. Adding the used FCC catalyst in the PP reduced most effectively the pyrolysis finishing temperature. In the PY-G.C. mass experiments, addition of zeolite type catalysts decreased the molecular weight of pyrolyzed product. In the batch system experiments, the mixing of used FCC catalyst enhanced best the initial yield of fuel oil, but the final yield of fuel oil was 2% higher in the case of mixing of natural zeolite. Also in the carbon number analysis, used FCC catalyst was the most useful one in this experiments for fuel oil.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.66-72
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• 2008

The photocatalytic degradation of a textile diazo dye in aqueous solution has been investigated under Solar and UV-A light. The effect of various parameters such as concentration of dye, amount of catalyst and pH on the degradation of dye has been studied. Addition of hydrogen peroxide, ammonium persulphate and isopropanol strongly influences the degradation rate. Kinetic analysis of photodegradation reveals that the degradation follows approximately pseudo first order kinetics according to the Langmuir-Hinshelwood model. Carbon dioxide, nitrate and sulphate ions have been identified as mineralisation products. The photocatalyst ZnO was found to be more efficient in UV-A light than in Solar light.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.281-289
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• 2015

This study investigated the conversion of oil products from polypropylene by using dispersed Co and Mo catalyst on reaction time and concentration change for knowledging liquefation characteristics at low-temperature (425, 450 and $475^{\circ}C$) pyrolysis in a batch reactor. The reaction time was set in 20~80 minutes and the oil products formed during pyrolysis were classfied into gas, gasoline, kero, diesel and heavy oil according to the domestic specification of petroleum products. The pyrolysis conversion rate was showed as Mo catalyst > Co catalyst > Thermal in all reaction time at reaction temperature $450^{\circ}C$. The conversion rate and yields of the pyrolysis products were the most height when Co and Mo Catalyst ratio was 50:50.

• Journal of the Korean Chemical Society
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• v.40 no.4
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• pp.254-263
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• 1996

Five cobalt(Ⅲ) complexes were synthesized from bi- or tridentate nitrogen ligands. Catalytic actions of these complexes for hydrolyses of p-nitrophenyl picolinate, p-nitrophenyl nicotinate, and p-nitrophenyl isonicotinate were investigated by a spectrophotometric method. p-Nitrophenyl picolinate showed the most senstive reaction among three substrates by these catalysts. Aquohydroxo Co(Ⅲ) complexes raised as much as 21∼40 times the rate of hydrolysis of p-nitrophenyl picolinate at pH 6.5. Activities of complexes were in the order: Co(ibpn)(OH)2(OH2) > Co(aepn)(OH)2(OH2) > Co(tn)2(OH)(OH2) > Co (bpy)2(OH)(OH2) > Co(dien)(OH)2(OH2). Catalytic hydrolysis was postulated to proceed through a intramolecular general base catalysis path which is mixed by a partial intramolecular nucleophilic catalysis.