• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.09a
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• pp.39-54
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• 2006

An experimental study on the hydro-cracking of recycling oil obtained from refused plastics was performed for up-grading of its fuel characteristics. Major experimental parameters were reaction temperature ($300^{\circ}C{\sim}700^{\circ}C$) and presence of catalysts (Al-Si, activated carbon, zeolite). The effect of the experimental parameters on the liquid product characteristics such as flash point, kinetic viscosity, and solid content was investigated. The hydro-cracking reactions of the recycling oil at $300^{\circ}C{\sim}400^{\circ}C$ improved the oil characteristics of the liquid products. Activated carbon was revealed as a stable and active catalyst in the hydro-cracking reaction at a temperature range investigated.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.323-327
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• 2011

A zeolite sheet (ceramic paper containing zeolite) made in a cylindrical configuration can be applied to a honeycomb rotor for the effective VOC removal. In this study, the zeolite sheet containing ZSM-5 was used as a support for Pt-loading, and its catalytic activity for the toluene combustion reaction was compared with those of the other Pt catalysts loaded on ${\gamma}-Al_2O_3$ and cordierite honeycomb. Pt/zeolite sheet catalyst showed a higher activity for toluene combustion reaction than that of $Pt/{\gamma}-Al_2O_3$ or Pt/cordierite honeycomb. On the other hand, the dispersion of Pt particles loaded on the zeolite sheet was improved by the pretreatment with $NH_3-H_2O$ vapor at room temperature. Consequently, the pretreatment of Pt/zeolite sheet by $NH_3-H_2O$ vapor significantly enhanced the catalytic activation for toluene combustion reaction.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.48-48
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• 2003

미세기공(microporous)을 가진 제올라이트는 다양한 유기질 분리의 촉매제 및 광학, 화학 센서, 기체 분리 등의 고기능 소재로서 크게 주목받고 있으며, 비표면적의 증가, 새로운 기능의 발현 둥으로 최근 들어 나노크기를 갖는 제올라이트 합성에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 기체 분리에 응용하기 위한 제올라이트 분리막 개발에 앞서 분리막 제조에 유리할 것으로 판단되어지는 적합한 크기와 형상을 갖춘 나노크기의 제올라이트를 합성하였으며 그 특성을 분석하였다. 출발물질로서 실리카 원으로는 TEOS, LUDOX AS-40, Cab-O-SIL 등을 사용하였으며, 템프레이트(TPAOH)와 함께 특정조성의 TPAOH/SiO$_2$,/$H_2O$ 겔을 만들었다. 합성시간을 단축할 수 있는 방법의 연구로서 저온하의 2단계 온도 변화법을 적용하였으며, 결정성장속도의 향상을 목적으로 NaH$_2$PO$_4$, H$_2$SO$_4$, NH$_4$OH 등의 결정화 촉진제로 사용하여 수열합성법으로 Silicalite-1를 합성하였다.

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.62-69
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• 1984

The reaction of toluene with ethanol was studied over various cation-exchanged pentasil zeolite catalysts. The toluene disproportionation reaction to produce xylenes increased with increasing reaction temperature and the activity of alkylation of toluene with ethanol showed maximum at around $400^{\circ}C$. Only Cs-ZSM-5 catalyst showed pronounced p-ethyltoluene selectivity increasing to 96% with increasing degree of Cs-exchange. The sorption rate of m-xylene was lower for Cs-exchanged ZSM-5 than H-ZSM-5 catalyst. These phenomena were interpreted in terms of shape selectivity arising from the partial blocking of channel intersections by large cesium ions.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.452-457
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• 2005

Foam-type MFI zeolite catalyst was prepared by dispersing fine ($-0.2{\mu}m$) particles of MFI zeolite on silicalite foam. Catalytic cracking of n-octane was investigated over the foam-type catalyst and Delplot method was employed to interpret product compositions for deducing reaction mechanism. The Si/Al molar ratio of dispersed MFI zeolite was estimated 25 and its dispersed amount of silicalite foam was 25 wt％. Since the apparent density of the foam type catalyst was very low $0.11g{\cdot}cm^{-3}$, the catalyst loading amount could be varied from 0.02 g to 0.5 g without concerning pressure drop, providing a wide variance in the residence time of the reactants and products. The conversion and olefin yield in the catalytic cracking of n-octane increased with the catalyst loading. The product composition was very simple and could be explained by applying the protolytic cracking mechanism when the catalyst loading was small. Higher loading of the catalyst brought about further reactions of cracked products, accumulating lower olefin and paraffin with low reactivity in product stream and resulting in complex product composition.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.712-718
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• 2016

Platinum catalysts supported on the mesoporous material synthesized from Y zeolite were applied to synthesis of jet-fuel through n-octadecane hydroupgrading. The mesoporous aluminosolicate, $MMZ_{HY}$ was synthesized using Y zeolite as its framework source. The effect of the addition of Mg to $Pt/MMZ_{HY}$ catalyst for n-octadecane hydroupgrading was investigated. Catalyst characterization was performed with X-ray diffraction, $N_2$ adsorption, temperature-programmed reduction in hydrogen flow, temperature-programmed desorption of ammonia, and infrared spectroscopy of adsorbed pyridine. The high yield of jet-fuel over the $PtMg(2.0)/MMZ_{HY}$ can be attributed not only to the higher dispersion of Pt metal and higher reducibility, but also the higher amount of acid sites and higher strength of acid sites. The selectivity to iso-paraffin in the jet-fuel fraction could be reached above 80% over the optimized $PtMg/MMZ_{HY}$ catalyst.

• 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.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.560-565
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• 2005

Catalytic performances of zeolite catalysts such as H-mordenite(HM), H-Beta$(H{\beta})$, H-USY(HUSY) for the transmethylation between 1-methylnaphthalene(1-MN) and 2-methylnaphthalene(2-MN) were investigated in a fixed-bed flow reactor. $H{\beta}$ showed higher and more stable conversion than others to exhibit a high and stable 2-MN/1-MN ratio of 2.3 and 2,6-DMN/2,7-DMN ratio of 1.3 at the $1^{st}$ hour of time on stream under the reaction conditions as follows: reaction temperature of $350^{\circ}C$, reaction pressure of 1.5 MPa, WHSV of $2.7g_{feed}/g_{cat}{\cdot}h$ and the molar ratio of 1-MN and 2-MN of 1:1. The catalytic behavior has been discussed in relation with the catalyst pore structure and acidity.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.125-128
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• 2001

• Applied Chemistry for Engineering
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• v.2 no.1
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• pp.1-11
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• 1991

Xenon-129 NMR technique has been developed since 1980 as a new method for the characterization of microporous materials such as zeolites, activated carbons and alumina by using chemical shift and linewidth variations in $^{129}Xe$ NMR of adsorbed xenon gas. This NMR technique has been known to be very effective to probe the locational and the chemical changes of the supported metallic species as well as the physicochemical change of the support material. Recently, this method has been successfully applied for the characterization of amorphous materials such as activated carbons, silica and alumina. Basic principles, experimental techniques and recent applications of the $^{129}Xe$ NMR method for the study of heterogeneous catalysts are introduced in this paper.