• Korean Chemical Engineering Research
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• 제44권4호
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• pp.345-349
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• 2006

SAPO-34 촉매상에서 DME(dimethyl ether) 또는 메탄올로부터 경질 올레핀(에틸렌, 프로필렌, 부텐)을 제조하는 반응을 수행하여, 각각의 올레핀들과 CO, $CO_2$와 같은 부 생성물의 수율을 반응온도와 시간의 흐름에 따라 비교해서 관찰하였다. DME 전환반응은 메탄올 전환반응과 비교하여 볼 때 촉매의 비활성화가 급격히 진행되었다. 물을 첨가할 경우, 올레핀의 수율을 증가와 함께 코크 생성에 의한 촉매의 비활성화가 감소하여 촉매의 수명이 길어짐을 확인하였다.

• 공업화학
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• 제34권5호
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• pp.548-555
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• 2023

SAPO-34 catalysts were modified with polyethylene glycol (PEG) and Pb to improve their catalytic lifetime and selectivity for light olefins in the conversion of dimethyl ether to olefins (DTO). Hierarchical SAPO-34 catalysts and PbAPSO-34 catalysts were synthesized according to changes in the molecular weight of PEG (M.W. = 1000, 2000, 4000) and the molar ratio of Pb/Al (Pb/Al = 0.0015, 0.0025, 0.0035), respectively. By introducing PEG into the SAPO-34 catalyst crystals, an enhanced volume of mesopores and reduced acidity were observed, resulting in improved catalytic performance. Pb was successfully substituted into the SAPO-34 catalyst frameworks, and an increased BET surface area and concentration of acid sites in the PbAPSO-34 catalysts were observed. In particular, the concentrations of the weak acid sites, which induce a mild reaction, were increased compared with the concentrations of strong acid sites. Then, the P2000-Pb(25)APSO-34 catalyst was prepared by simultaneously utilizing the synthesis conditions for the P2000 SAPO-34 and Pb(25)APSO-34 catalysts. The P2000-Pb(25)APSO-34 catalyst showed the best catalytic lifetime (183 min based on DME conversion > 90%), with an approximately 62% improvement compared to that of the unmodified catalyst (113 min).

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.69-83
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• 2020

경질 올레핀은 중요한 석유화학제품일 뿐 아니라 다양한 화학 중간체들을 위한 기본 구성체이다. 최근 에틸렌이 생산 제품의 대부분을 차지하는 Ethane Cracking Center (ECC) 공정이 크게 늘어남에 따라 프로필렌 공급이 매년 꾸준히 증가하는 프로필렌 수요를 따라잡지 못하고 있다. 이에 따라 프로필렌의 수요를 따라잡기 위하여 메탄올로부터 올레핀으로 전환하는 기술이 보다 중요하게 되었다. Methanol to olefins (MTO) 공정은 합성가스를 통해 메탄올을 생산하고 메탄올로부터 프로필렌 등 올레핀을 생산한다. 메탄올을 올레핀으로 전환하는 반응은 사용되는 촉매에 따라 다른 반응생성물 조성을 갖기 때문에 생성물에 따른 적절한 분리 방법이 고려되어야 한다. 따라서 네 가지의 대표적인 반응 생성물 조성들에 대하여 네 가지의 분리공정 대안들을 Aspen plus를 이용하여 모사하였다. 또한 모사 결과를 바탕으로 기술적 경제적 분석을 통하여 MTO 공정의 반응 생성물 조성에 대한 각 분리공정의 성능을 평가하였으며, 이를 통해 MTO 공정의 반응기에서 생산되는 생성물 조성에 따라 적합한 분리공정 선정을 위한 지침을 제시하였다.

• 공업화학
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• 제25권1호
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• pp.34-40
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• 2014

메조 세공을 갖는 SAPO-34 촉매를 2차 주형 물질로서 탄소 나노튜브(CNT)를 이용한 수열 합성 방법에 의해 성공적으로 합성했으며, CNT 첨가량(0.5, 1.5, 2.5 및 4.5 mol%)이 촉매 성능에 미치는 영향을 조사하였다. 합성된 촉매들은 X-선 회절 분석(XRD), 주사 전자 현미경(SEM), 질소 흡탈착 등온선 및 암모니아 승온 탈착($NH_3$-TPD)을 통해 특성분석을 수행하였다. 합성된 촉매 중에서 1.5 mol% CNT를 첨가하여 제조된 SAPO-34 (1.5C-SAPO-34)가 가장 큰 메조 세공부피를 나타냈을 뿐만 아니라 총 산점의 양도 가장 높은 것으로 관찰되었다. 그러나 CNT의 함량을 그 이상 첨가하여 제조한 촉매들의 경우 결정의 크기가 너무 작아 오히려 메조 세공의 부피가 감소하는 것으로 나타났다. 제조된 촉매들의 dimethyl ether to olefins 반응에서 CNT 함량에 따른 촉매 수명과 경질 올레핀($C_2{\sim}C_4$)의 선택성을 연구하였다. 그 결과 1.5C-SAPO-34 촉매는 기존의 SAPO-34 촉매와 비교하여 더 우수한 경질 올레핀 선택도와 약 36%의 향상된 촉매수명을 나타났다.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1832-1834
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• 2009

A simple and safe method has been presented for conversion of olefins into bromohydrins using hydrogen bromide and hydrogen peroxide as bromide source by visible light induced within a very short time to get high yield bromohydrins along with a little mount dibromo-product. In this paper, cyclohexene is firstly carried out as the model substrate and investigated the bromination under HBr/$H_2O_2$ system using 150 W incandescent light irradiated in C$Cl_4$ within short time to get good yield of 2-bromocyclohexanol along with a little mount of 1,2-dibromocyclohexane; then, a series of alkenes are brominated to corresponding bromohydrins using the same protocol.

• Rapid Communication in Photoscience
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• 제4권1호
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• pp.19-21
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• 2015

Zeolite is an ideal host material for encapsulating nano-size metal catalyst species because of its defined microporous structure, prominent adsorption/condensation properties, high surface area, chemical/thermal stability, and transparency to light. In this study, $TiO_2$ photocatalyst was incorporated in highly hydrophobic Y zeolite and its photocatalytic activity was examined in the photocatalytic oxidation of olefins under UV-light irradiation using molecular oxygen as an oxygen source. $TiO_2$ nanoparticles incorporated in hydrophobic Y zeolite exhibited a markedly enhanced photocatalytic activity compared with bare $TiO_2$ owing to its excellent affinity toward organic moieties, which facilitates the mass transfer of organic substrates and allows them to efficiently access to the neighboring active $TiO_2$ surface.

• 자연과학논문집
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• 제5권2호
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.563-566
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• 2002

Copper complexes have been directly incorporated into cellulose acetate (CA) and the resulting light blue colored homogeneous films of 5-20 wt.% copper acetate complex concentrations are found to be thermally stable up to 200 $^{\circ}C$. The reaction chem istry of Cu in CA has been investigated by reacting them with small gas molecules such as CO, H2, D2, O2, NO, and olefins in the temperature range of 25-160 $^{\circ}C$, and various Cu-hydride, -carbonyl, -nitrosyl, and olefin species coordinated to Cu sites in CA are characterized by IR and UV/Vis spectroscopic study. The reduction of Cu(II) complexes by reacting with H2 gas at the described conditions results in the formation of Cu2O and copper metal nanoparticles in CA, and their sizes in 30-120 nm range are found to be controlled by adjusting metal complex concentration in CA and/or the reduction reaction conditions. These small copper metal particles show various catalytic reactivity in hydrogenation of olefins and CH3CN; CO oxidation; and NO reduction reactions under relatively mild conditions.

• 한국수소및신에너지학회논문집
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• 제22권2호
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• pp.232-239
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• 2011

DME has received much attention because of its possible use as a fuel and a chemical feedstock. Chemical conversion of DME to olefin (DTO) over various SAPO-34 catalysts was carried out using a fixed bed reactor. Main products of the reaction were light olefins such as ethylene, propylene and butenes. The best reaction conditions for high life time of the catalyst and high selectivity of light olefins were a reaction temperature of $400^{\circ}C$ and a WHSV of $3.54h^{-1}$. In addition, it was found that the deactivation of a SAPO-34 catalyst can be significantly suppressed by the addition of $ZrO_2$ as a supporter.

• 한국대기환경학회지
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• 제24권3호
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• pp.275-283
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• 2008

Since mobile source is a major source of VOCs, quantifying emissions from motor vehicles is an important factor to control VOCs in atmosphere. In this study, in order to evaluate tailpipe VOCs emissions from motor vehicles, mass emissions of non-methane volatile organic compounds from 45 vehicles were determined. Measurements were made on a chassis dynamometer using CVS-75 mode and speed specific drive modes. Target VOCs are 53 compounds determined as the volatile ozone precursors. The individual VOCs composition of vehicle emission and emission rates were also determined. In case of gasoline vehicles, VOCs emission from over 80,000 km vehicles were about 46% larger than less 80,000 km vehicles. The difference in benzene and toluene according to driving mileage was 44% and 26% respectively. The composition of VOCs were different by fuel type. The order of VOCs composition was paraffins>aromatics>olefins in gasoline vehicle emissions, paraffins>olefins>aromatics in light duty diesel vehicle emissions. The VOCs emissions were decreased as vehicle speed increasing. These results will be used to calculate total VOCs emissions from automobiles in the future.