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선택적 촉매 산화 반응에 의한 황화 수소의 제거 Ⅱ . TiO2 / SiO2 촉매 상에서 황화 수소의 선택적 산화 반응
천승우,박대원,우희철,홍성수,정종식 ( S . W . Chun,D . W . Park,H . C . Woo,S . S . Hong,J . S . Chung ) 한국공업화학회 1996 공업화학 Vol.7 No.4
본 연구는 H₂S를 TiO₂/SiO₂촉매상에서 산소와의 직접 산화 반응을 통해 원소 황의 형태로 제거하는 반응에 관한 것이다. 순수한 TiS₂Ti(SO₄)_2를 사용한 반응 실험과 순수한 TiO₂에 대한 주기적 온도 조작 실험 결과로부터 TiO₂는 황 회수 공정에서 사용되는 촉매의 비활성화의 주원인으로 알려진 sulfation이나 salfidation에 대해 매우 안정한 것으로 나타났다. TiO₂/SiO₂촉매에서 TiO₂의 담지량이 증가함에 따라 H₂S 전화율이 증가하였고, 원소 황의 선택도는 아주 소폭으로 감소하였다. 반응 실험결과 O₂/H₂S의 비가 증가할수록 원소 황의 선택도는 크게 감소하였다. 10 wt.% TiO₂/SiO₂ 촉매는 화학 양론비의 조성(H₂S=5 vol.% O₂=2.5 vol.%)의 반응물에 10 vol.%의 수증기를 첨가한 경우 활성과 선택도가 감소하였으나 여전히 80% 이상의 원소 황 수율을 유지하고 있었다. Selective catalytic oxidation of H₂S to elemental sulfur using TiO₂/SiO₂ catalysts was investigated in this study. The reaction test with pure TiS₂and Ti(SO₄)₂and cyclic temperature operation revealed that TiO₂had a good resistance to sulfation and sulfidation, which are known as the main cause of catalytic deactivation in sulfur recovery process. With the increase of TiO₂loading amount in Tio₂/SiO₂catalysts, the conversion of H₂S increased and the selectivity of elemental sulfur was very slightly decreased. As the ratio of O₂/H₂S increased, the selectivity to elemental sulfur was drastically decreased. In the presence of 10 vol.% water vapor to a stoichiometric mixture of H₂S and O₂(H₂S =5 vol.% O=2.5 vol.%), both activity and selectivity of 10 wt.% TiO₂/SiO₂catalyst are decreased, but it still showed more than 80% of sulfur yield.
선택적 촉매 산화 반응에 의한 황화수소의 제거 1 . 촉매의 개발
천승우,박대원,우희철,홍성수,정종식 ( S . W . Chun,D . W . Park,H . C . Woo,S . S . Hong,J . S . Chung ) 한국공업화학회 1995 공업화학 Vol.6 No.5
본 연구는 H₂S를 산소와의 직접 산화 반응을 통해 원소 황의 형태로 제거하는 반응에서 고농도의 H₂S를 처리할 수 있는 촉매의 개발에 관한 것이다. 최적의 촉매를 개발하기 위해 각 담체와 금속 산화물에 대한 반응성 실험을 실시하였다. 실험 결과 담체로는 Al₂O₃, TiO₂, ZrO₂ 등이 금속 산화물로서는 Fe₂O₃, V₂O_5, SnO₂, Cr₂O₃ 등이 좋은 활성을 보였다. 반응물 중의 산소의 분압 영향과 반응물에 포함되어질 수 있는 물의 영향에 대해서 관찰한 결과 산소의 분압이 높을수록 전화율은 증가하나 황 선택도는 급격히 감소하는 경향을 보였고, 10vol.%의 물을 반응물에 첨가한 경우 전화율과 황 선택도가 동시에 감소하는 경향을 보였다. In this study, development of catalysts far the direct oxidation of hydrogen sulfide to elemental sulfur, specially for the treatment of high concentrantion of H₂S, was investigated. To find out optimum catalysts, a screenig test for various supports and metal oxides was carried out. Among the supports tested, Al₂O₃, TiO₂ and ZrO₂ showed good catalytic activity. Fe₂O₃, V₂O_5, SnO₂ and Cr₂O₃ have been considered to be active metal oxides. The study on the effects of oxygen partial pressure revealed that the conversion of H₂S increased with increasing the ratio of O₂/H₂S, but the selectivity to sulfur was drasctically decreased. Bath of the conversion of H₂S and the selectivity to sulfur were decreased when 10 vol.% of water was added to the mixture of H₂S and oxygen.
박대식,윤석훈,김명환,이영호,오철,Park, D.S.,Yoon, S.H.,Kim, M.H.,Lee, Y.H.,Oh, C. Korean Society of Marine Engineers 2001 한국마린엔지니어링학회지 Vol.25 No.4
This study was experimentally performed to investigate freezing behavior of sea water along horizontal cooled a circular tube with bubbly flow. The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-tube temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. And the flow patterns around cooled tube were visualized using the PIV to analyze the relationship between the flow structure and the freezing characteristics. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.
충돌면 형상 및 위치 변화가 디젤분무에 미치는 영향에 관한 연구
박대순(D. S. Park),김문헌(M. H. Kim),박권하(K. Park),이장희(J. H. Lee),정용일(Y. l. Jeong) 한국자동차공학회 1996 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1996 No.6_2
Most of the research of small engines to date focused on developing spark ignition engines occupied much parts. Recently the number of small D.I. diesel engines applied in small cars has been increased and considered as a next generation power source for passenger cars because of its high efficiency. Therefore the combustion chamber becomes smaller and the fuel injection pressure goes higher, which makes fuel sprays impinged easily on the combustion chamber walls. In result without strong swirls the fuel may not mix with air because of fuel deposition on the wall.<br/> As a positive way, the combustion chamber systems which is using spray impaction on a wall has been introduced and assessed by an experimental or a simulative manner. In these systems the raised lands are positioned in the chamber for spray impaction in order to break up the fuel drops into much smaller and direct them into desired direction.<br/> This study addresses to the position and size of the raised land to help the chamber design using spray wall impaction. The characteristics of the spray impinged on various lands are investigated and compared with each other. Then the chamber shapes are discussed with the spray characteristics and the proper position and size is proposed in any chamber volume.