Physico-Chemical Properties of Silver Ion Exchanged Zeolites

徐聖奎 여수대학교 1991 論文集 Vol.5 No.-

Physico-chemical properties of silver exchanged zeolites such as A-type, L-type, Mordenite, X-type and Y-type were studied by TPR, stepwise hydrogen reduction, XRD and infrared spectroscopy of the adsorbed CO and pyridine. The different reduction behavior of zeolites may be explained in terms of the site preference and the migration behavior of silver cation in the zeolite structure. The structure of AgA-95 and AgX-99 were destroyed, but the structure of AgL-48, AgM-38 and AgY-98 zeolites were retained as a result of hydrogen reduction. With the repeated reduction and oxidation, the reversibility of the silver cations and the metallic silver species was observed in the infrared spectra of the adsorbed CO and the XRD. With the hydrogen or deuterium reduction, the formation of acidic protons over the silver exchanged zeolites was also observed in the infrared spectra of the adsorbed pyridine. Hydrogen was chemisorbed reversibly and dissociatively on reduced silver exchanged zeolites. The active site to chemisorb hydrogen must be cationic silver cluster, ??.

코발트 담지 카본블랙 촉매를 이용한 아세트알데히드 산화반응

서성규,윤형선 國立 麗水大學校 環境問題硏究所 2002 環境硏究論文集 Vol.5 No.-

This study was performed to investigate the possibility of acetaldehyde oxidation on Co/carbon black catalyst. The experiment was conducted at the reaction temperature of 200~440℃, the acetaldehyde concentration of 0.94mole% in air and the cobalt loading amounts of 2~60wt%. The characterization of the carbon black and Co/carbon black catalyst was carried out by TGA and XRD analysis. The thermal characteristics of the carbon black was stable to the high temperature(600℃). XRD result showed that Co/carbon black were destroyed and new metal oxide were formed such as Co_(3)O_(4). Co_(3)O_(4) crystallite addition on the catalysts surface provided the greatest enhancement of the catalytic activity. The order of activity on acetaldehyde oxidation was summarized as follow: SiO_(2)<TiO_(2)<carbon black<SiO_(2)-Al_(2)O_(3). It was found from the experimental results and the economic consideration that carbon black could effectively be utilized as a support for acetaldehyde oxidation. The activity of Co/carbon black catalyst were varied with the cobalt loading amount and the optimum loading content of cobalt was found 10wt%.

대학캠퍼스와 광양만 주변지역의 대기질에 관한 연구

서성규,이선원,문정선 國立 麗水大學校 環境問題硏究所 2000 環境硏究論文集 Vol.3 No.-

By the air quality standard of korea, the 7 major pollutants should be continuously monitored; that is SO_(2), NO_(2), O_(3), CO, PM10, TSP and Pb, At present, air monitoring system is furnished at 6 site around Kwangyang-bay which has been assigned to the air pollution special measure area as well as the air quality regulation area. According the measurement results of the university campus, the present levels of pollutants were not exceed the limit level of air quality standard, but the levels of some pollutants were high at special period of a day. It may be recommended to monitor continuously for the long-term. The monitoring results of SO_(2), NO_(2), O_(3) and CO showed that SO_(2), NO_(2) and CO level were well within the limit levels of air quality standard. The O_(3) levels were not exceed the limit levels of air quality standard, but high enough to concern based on one and eight hour average levels. Especially for monitoring data at Weollae-dong district The O_(3) levels were approaching the limit levels of air quality standard. The pattern of O_(3) and NO_(2) increase due to the photo-oxidation in the industrial district was not similar th that residential district

석유화학공단 지역의 대기중 황화합물에 관한 연구

서성규,김상채 國立 麗水大學校 環境問題硏究所 1998 環境硏究論文集 Vol.1 No.-

The odor of sulfur compounds which are of air pollutants in petroleum industrial complex was investigated. Concentration vs. peak areas resulted from analyzing four sulfur compounds within the ranges of very low concentration by GC method were correlated. Correlation coefficients of four sulfur compounds were found to be above 0.9941 and very good. No sulfur compounds exception hydrogen sulfide(H₂S) were detected at four measuring sites. Also, concentration of hydrogen sulfide was much lower than an emission standard(0.2ppm) within the industrial area. Concentration of hydrogen sulfide was insignificantly changed with times and sites of sampling. However, average concentration of hydrogen sulfide of #2 site was higher than other sites.

자동차 폐촉매를 이용한 VOCs 연소 활성 ( VOCs Combustion Activity of Waste Automotive Catalyst )

서성규,문정선 한국대기환경학회 2000 한국대기환경학회 학술대회논문집 Vol.- No.-

TiO₂ 광촉매의 Acetaldehyde 광분해 특성

서성규,이선원,정상철,정채훈 한국공업화학회 2001 한국공업화학회 연구논문 초록집 Vol.2001 No.-

최근 대기오염물질 중 휘발성 유기화합물(VOCs: volitale organic compounds)에 대한 관심의 집중과 처리기술에 대한 연구가 활발히 진행되고 있다. 이들 처리기술은 촉매소각, 열소각, 흡착, 흡수 및 응축 등 여러 가지 원리가 이용되고 있다. 최근 다방면에서 관심의 대상이 되는 TiO₂를 이용한 광촉매 산화는 저온연소, 내화학성, 폭발위험이 적고, 수분에 대한 활성저하가 없는 장점을 가지고 있다. TiO₂ 광촉매는 대부분 졸겔법에 의해 제조되어 왔으나, 불순물의 잔존과 결정의 결함이 많아 촉매의 활성을 저하시키는 전자와 정공의 재결합 현상이 많이 발생하는 문제점을 가지고 있다. 따라서, 본 연 구에서는 CVD(chemical vapour deposition)법으로 anatase 결정구조의 TiO₂막을 Alumina ball에 코팅 하여 제조한 광촉매를 이용하여 acetaldehyde 분해특성에 관하여 연구하였으며, hybrid system 구성기술로서의 가능성을 파악하였다. 반응물인 acetaldehyde는 일정온도로 유지되는 항온조를 이용하여 head space 방식을 이용하여 TiO₂ 광촉매가 충진된 반응기에 연속적으로 공급한 후, UV-C(λmax=253.7nm, 10w)를 조사하여 acetaldehyde 분해특성을 GC(SHIMADZU, GC-8A)로 분석하였다. 실험시 유량은 60cc/min, acetaldehyde 농도는 1 mol%미만의 농도로 공급하였다. Acetaldehyde의 광촉매 분해 생성물로는 CO₂, H₂O, HCHO, HCOOCH₃, CH₄, CO 등이 관찰되었다. 광촉매의 경시변화를 측정한 결과 48시간 동안 전화율은 일정하게 유지되었으며, 반응 시간의 경과에 따른 활성변화는 관찰되지 않아 경제적이고 안정성이 높은 VOCs 처리 기술로서의 가능성을 보았다.

Al-doped Uvarovite 안료의 합성과 특성

서성규,이병하,Seo, Sung-Gyu,Lee, Byung-Ha 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.6

Uvarovite Garnet is green pigment prepared by using $Cr_2O_3$, CaO and $SiO_2$ which are widely used in ceramic industry. The synthesis of above pigment was carried out by mixing $K_2Cr_2O_7$, $SiO_2$ and $CaCO_3$ as formulated and then firing at $1000{\sim}1200^{\circ}C$. To investigate the optimum synthesis condition of the Uvarovite Garnet. it was prepared by using CaO to replace $CaCO_3$, $CaF_2$ and $CaCl_2$. To get green brighter color, $Al^{3+}$ was substituted for $Cr^{3+}$. They were characterized by X-ray diffraction, UV-Vis spectroscopy, Raman spectroscopy and SEM analysis. When the pigments were applied to lime glazes (6 wt%), color parameters of Uvarovite Garnet showed the $L^*$=40.99, $a^*$=-16.23 and $b^*$=17.04.

망간 산화물 촉매의 VOCs 연소 특성 ( Characteristics of VOCs Combustion over Mn Oxides Catalyst )

서성규,윤형선,김상채 한국대기환경학회 2000 한국대기환경학회 학술대회논문집 Vol.- No.-

암모니아 공정에서 CO₂ 고정의 최적화

서성규,이정섭,송준석 國立麗水大學校 環境問題硏究所 2004 環境硏究論文集 Vol.6 No.-

This study was investigated the effects of various system parameters on the absorption of carbon dioxide into absorption solution. An aqueous potassium carbonate solution was used as a chemical absorbent in order to figure out the effect of chemical reaction. For this purpose, the chemical analysis of potassium carbonate solution was performed. The changes of pressure, temperature, K₂CO₃solution flow/feed gas ratio and solution concentration in the absorber and the changes of pressure and temperature in the stripper were also analyzed. The analysis result shows that K₂CO₃ concentration in potassium carbonate solution was 99.6%. The optimum pressure was found to be 27.0㎏/㎠ and the optimum temperature was to be 68℃, the optimum concentration of potassium carbonate solution was to be 26.0wt% in the absorber. The CO₂ leakage decreased with the increment of the K₂CO₃ solution flow/feed gas ratio. But the H₂ leakage in the CO₂ product increased at or above the K₂CO₃ solution flow/feed gas ratio of 1.10. This H₂ leakage induced by the loss of ammonia production. The effects of the changes of the operation condition of the CO₂ stripper to the K₂CO₃ conversion are as follows. The K₂CO₃ conversion decreased as the pressure decreased. The K₂CO₃ conversion increased as the temperature increased. However, increasing the temperature without decreasing the pressure did not bring positive effect. The optimum pressure was found to be 0.45㎏/㎠.

코발트 담지 촉매상에서 아세트알데히드의 연소

서성규,유형선,김상채 한국공업화학회 2001 한국공업화학회 연구논문 초록집 Vol.2001 No.-

VOCs 처리에 촉매연소를 이용하는 경우, 사용되는 촉매는 귀금속(Pt, Pd 등)계 및 금속산화물 촉매로 크게 분류할 수 있다. 귀금속 촉매의 경우,높은 활성과 열적 내구성이 뛰어나지만, 경제적 부담이 크다는 문제점이 있다. 비용이 저렴한 금속산화물 촉매의 경우, 부분연소생성물로 인한 완전연소의 어려움이 있어, 금속산화물 촉매의 활성 증가를 위해 조촉매 및 우수한 지지체(카본블랙, SiO₂, Al₂O₃, TiO₂ 등)를 이용하여, 새로운 담지 촉매를 개발하는 많은 연구들이 보고되고 있다. 다양한 지지체중 비교적 경제적이고, 비표면적이 큰 카본물질(카본블랙, 활성탄, 흑연)의 경우, VOCs를 흡착하는 기본 적인 특성을 갖고 있어 지지체로서 유리한 측면이 있다. 이러한 특성 때문에 금속산화물(Co₃O₄, CoO, CrO₃)을 카본물질에 담지시켜 제조한 촉매상에서 VOCs 촉매산화에 관한 연구가 보고되고 있다. 따라서, 본 연구에서는 methand과 acetaldehyde의 연소 활성이 우수한 Co-PC를 카본블랙에 담지한 촉매의 연소 특성에 관하여 연구하였다. 담지량 및 반응온도 등의 영향을 검토하였으며,Co-PC/C 촉매의 상대적 활성을 평가하기 위하여 상용의 RCO 촉매 활성과도 비교하였다. 물리화학적 특성조사로는 지지체에 대한 열적 안정성을 TGA(Thermogravimetric analyzer), 결정구조 분석은 XRD(X-ray Diffractometer)를 이용하여 조사하였다. 지지체인 카본블랙은 600t까지 안정하였으며, 유기용매에 대한 영향은 관찰되지 않았다. 공기로 전처리한 Co-PC/C 촉매중 Co는 Co₃O₄ 산화물형태로 존재하였으며, acetaldehyde 연소시 활성점으로 작용하는 것으로 판단된다.