• Journal of the Korean Chemical Society
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• v.34 no.4
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• pp.360-369
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• 1990

Borosilicate, HZSM-5 zeolite and iron-substituted borosilicate and HZSM-5 zeolite were prepared and their catalytic properties in methanol conversion were studied. The effects of strength and amount of acid site determined from TPD spectra of ammonia on the product distribution was examined. Selectivity to propylene was high over borosilicate with small amount of strong acid site, but selectivity to aromatic compound was high over HZSM-5 zeolite with large amount of the strong acid site. The participation of weak acid site on the conversion did not confirmed, and the product distribution could be explained in terms of the amount of the strong acid site. Although the amount of the weak acid site was increased by substitution of iron, there was no meaningful change in the product distribution.

• Clean Technology
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• v.14 no.4
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• pp.271-274
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• 2008

In this work, the feasibility of spent zeolite catalyst for reusing as a support was investigated in catalytic odor removal reaction. As a model reaction for odor removal, toluene was selected as a reactant. 10wt% Cu was impregnated on spent HZSM-5 catalyst and spent FCC catalyst. The catalytic activity of the spent HZSM-S was higher than that of spent FCC catalyst in toluene oxidation. This was due to the fact that the surface area of spent HZSM-S was higher than that of spent FCC catalyst. These results may suggest that spent HZSM-S can be reused as a cheap catalyst for toluene removal.

• Journal of the Korean Chemical Society
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• v.37 no.3
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• pp.317-326
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• 1993

The acid catalytic reactions of toluene with n-propylalcohol were investigated and the adsorption experiments of dialkylbenzene isomers were carried out at 100$^{\circ}C$ over modified HZSM-5 zeolites. ZSM-5 zeolite was synthesized by the hydrothermal reaction using 4-propylammonium ion, sodium aluminate and colloidal silica etc., and several zeolite catalysts, including H-, K-, Sr-, P-Mg-HZSM-5, H-Y and H-mordenite, were prepared by conventional methods. The main reaction products of toluene with n-propylalcohol over HZSM-5 catalyst include not only xylenes, propyltoluenes, but also ethyltoluenes and high para-selectivity among dialkylbenzene isomers was observed on P-Mg-HZSM-5 zeolite. The diffusion coefficients of various p-dialkylbenzenes are nearly the same, about 1 ${times}$ 10$^{-10}$ cm$^2$/sec and that of m-xylene was about one tenth of o-xylene. These reaction and adsorption characteristics were interpreted in the light of the shape-selectivity related to related to the zeolite pore structure and the zeolitic acidity.

• Journal of the Korean Institute of Gas
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• v.9 no.4 s.29
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• pp.17-25
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• 2005

The dealuminated and alkali/alkaline-earth metal exchanged Y-zeolites were prepared as a catalyst. Elemental compositions and structures of the prepared catalysts were analyzed by the various spectroscopic techniques such as inductively coupled plasma-atomic emission spectroscopy(ICP-AES), X-ray fluorescence(XRF) and X-ray diffraction(XRD), and the desorption behaviors of adsorbed species on the catalyst surfaces were investigated via NO-TPD experiment. Comparing with the composition of the starting material of NaY zeolite, the magnitudes of Si/Al ratio in catalytic materials were increased after dealumination. The Si/Al ratio of catalytic materials after dealumination followed by Cs and Ba cation exchange were additionally decreased. Dealumination to catalysts induced a destruction of basic frame due to a detachment of aluminum, which results in reducing framework structure, while increasing non-framework structure. This phenomenon becomes more serious with increasing time of steam treatment and even more significant for the cation exchanged catalysts. In NO-TPD experiments, the desorption peaks of NO which indicates an activity point of catalysts shifted to the low temperature region after dealumination and cation exchange. The desorption peaks of the NO-TPD profiles taken after steam treatment also shifted to the low temperature region as the steam treatment time increased. In dealuminated and cation exchanged Y-zeolites, the catalytic activities were more influenced by exchanged cation and the formation of non-framework structure.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.11a
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• pp.8.2-8.2
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• 2006

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.98-99
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• 2002

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.209-213
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• 2002

최근 들어 메탄올 환원제로 사용하는 이산화탄소의 촉매 개질 반응이 많은 주목을 받고 있다. 메탄에 의한 이산화탄소의 개질 반응 시 생성되는 합성 가스는 기존의 수증기 개질 반응에서 생성되는 합성 가스에 비하여 $H_2$/CO의 비가 낮으며 직접 메탄올 및 DME와 같은 유용한 물질로의 전환이 유리하므로 이에 대한 연구가 활발히 진행 중에 있다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.57-60
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• 2002

국내에서 사용되고 있는 대부분의 화재대피용 방독마스크 정화통은 외국에서 고가에 수입되고 있거나, 국내 제조시는 많은 기술을 외국에 의존하고 있다. 이들 정화통의 충진재는 일산화탄소(CO)를 제거하기 위해 망간(Mn), 구리(Cu)등을 활성탄에 담지시켜 제조한 촉매층과 $SO_2$, HCI 등의 유독가스를 제거하기 위한 제올라이트 등의 흡착층으로 구성되어있다. 그러나 이들 충진재중 CO 제거용 촉매는 상온에서 CO의 제거효율이 낮아 많은 양을 충진해야 하는 어려움이 있다.(중략)

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.407-414
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• 2016

Ex-situ catalytic pyrolysis of a Korean native oak tree over microporous zeolites (HZSM-5, HBeta, and HY) was performed by using a fixed bed reactor. The effect of sample to catalyst ratio and reaction temperature was also investigated to optimize production conditions of high quality bio-oil. Among three catalysts, HZSM-5 showed the highest aromatic formation due to its proper pore size and strong acidity. Although HY and HBeta also showed the catalytic activity, they produced larger amounts of coke due to their larger pore size. The smaller ratio of the sample to the catalyst and higher reaction temperature were also required to maximize the yields of aromatic hydrocarbons via the catalytic pyrolysis of oak tree over HZSM-5.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.902-912
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• 1996

In the skeletal isomerization of 1-pentene over various solid acid catalysts, we have studied catalytic reactivity, selectivity, reaction mechanism and the relation between acid strength of catalysts and catalytic activity. Natural zeolite shows highest activity among the all catalysts and the modified ${\eta}$-alumina with fluorine and sulfuric acid shows higher activity than unmodified ${\eta}$-alumina. The yield of isopentene increases with increasing temperature and increasing contact time. However the cracking products increase at the high temperature and very high contact time. In addition, the activity of natural zeolite exchanged with metal cation decreases and shows good relation with the polarizing power of metal cation. According to the result of ammonia TPD, the acid strength of catalysts has an effect on catalytic activity.