• 제목/요약/키워드: catalytic reduction

검색결과 769건 처리시간 0.022초

HC-DeNOx 촉매용 인젝터의 분무 특성 연구 (Spray Characteristics of Injector Used for HC-DeNOx Catalyst System)

  • 이동훈;정해영;이기형;이진하;여권구
    • 대한기계학회논문집B
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    • 제31권2호
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    • pp.167-172
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    • 2007
  • A new method that optimizes a control of hydrocarbon (HC) addition to diesel exhaust gas for HC type DeNOx catalyst system has been developed. These catalysts are called the HC-DeHOx catalyst in this paper. The system using HC-DeNOx catalyst requires a resonable quantity of hydrocarbons addition in the inlet gas of the catalyst, because the HC concentration in a diesel engine is so low that the HC is not sufficient for NOx conversion. It is expected that this study offers a robust data developing HC injection system.

Selective Hydrogenation of 1,3-Butadiene over Supported Nickel Catalyst Obtained from Nickel-Zirconia Solid Solution

  • Chang, Jong-San;Ryu, Jae-Oak;Lee, Jong-Min;Park, Sang-Eon;Hong, Do-Young;Jhung, Sung-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제26권10호
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    • pp.1512-1514
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    • 2005
  • Catalytic properties of Ni-Zr$O_2$ catalysts prepared by coprecipitation have been studied for the gas-phase hydrogenation of 1,3-butadiene to butenes. The coprecipitation method led to the solid solution of Ni-Zr$O_2$, which contains highly resistant Ni species to thermal reduction with H2. Nickel species of the solid solution were highly dispersed in the ZrO2 lattice, so that the reduced catalysts were selective for hydrogenation of 1,3-butadiene to butenes (99.9%) even in the presence of 1-butene.

무전해도금(I) (Review on Electroless Plating(I))

  • 김만;권식철
    • 한국표면공학회지
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    • 제19권3호
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    • pp.121-127
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    • 1986
  • There are many plating methods already commercially employed in te surface technology. One of the plating methods is electroless (chemical) plating, which is deposited by auto-catalytic reduction of metallic ion with the reducing agent in the plating bath. And it has many advantages comparing with electrolytic plating in respect of properties of deposit, such as corrosion resistance, wear resistance, uniformity, hardness, adhesion and so on. So, electroless plating is the fatest growing process in metallization of plastic and electronic industry. The properties and numerous applications of electroless deposits are attracting more and more attention from finish specifies. Many metal finishers are considering set-up of new electroless line in their shops. This review will be beneficial to domestic metal finishers to understand the real status of present electroless plating technology. It will also provide some knowledge on the economic aspect of electroless plating for the commercial application of specific parts.

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페로브스카이트형 촉매계를 이용한 고정원 배가스로부터의 NOx 와 SOx의 동시제거 기술에 관한 연구 (The Studies on the Simultaneous Removals of NOx and SOx from Stationary Sources by using Perovskite type Catalysts)

  • 이병용;정석진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.475-479
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    • 1996
  • At present studies, we are going to suggest the new type of Perovskite derived catalysts which modify the defects of transition metals impregnated. Perovskite type catalyst is a typical mixed metal oxides, and there are "defect"s (from like that oxygen, cation, crystallic structure) were made by difference from composition, preparing method and so forth. And because this, its electro-magnetic character could be much changed. By using this phenomena, it could utilize the modification of adsorption/desorption characters as well as the catalytic activities in NOx reduction. Because perovskite type catalyst can exchange the metal of the each lattice site freely and it is possible to represent the peculiar.

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과산화수소 정량을 위한 장미조직 함유 바이오센서의 전기화학 속도론적 고찰 (Electrochemical Kinetic Assessment of Rose Tissue Immobilized Biosensor for the Determination of Hydrogen Peroxide)

  • 유근배
    • 공업화학
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    • 제25권1호
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    • pp.107-112
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    • 2014
  • 흑연가루의 결합재로 클로로술폰화 폴리에틸렌 고무용액을, 매개체로 ferrocene을 사용하여 장미조직을 고정한 과산화수소 정량 바이오센서를 제작하였다. 실험 전극전위 영역에서 보여준 Hanes-Woolf 도시의 선형성은 기질의 환원이 장미 과산화효소의 촉매력에 의한 것임을 보여 주었다. 또 얻어진 10개 이상의 전기화학 파라미터들은 전극이 정량적으로 성능을 발휘하고 있음을 입증하였다. 이런 사실들은 효소전극의 실용화를 위하여 장미조직이 상업용 과산화효소를 대치하여 사용될 수 있음을 확신시켜 주는 것이었다.

The Chemistry of Rhodium in Polysulfone: Reactions with Various Small Gas Molecules

  • Il-Wun Shim;Jin-Si Kim;Seok-Jong Oh;Yong-Sik Yang;Hwan-Kyu Suh;Sang-Kyu Lee
    • Bulletin of the Korean Chemical Society
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    • 제15권2호
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    • pp.126-132
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    • 1994
  • RhCl [P($C_6H_5)_3]_3$ complexes have been incorporated in polysulfone (PS) as a dispersion medium using cosolvent (THF). The interactions between Rh(Ⅰ) complexes and polysulfone polymer molecules are examined by infrared spectroscopy and thermal analysis. The chemical reactivity of Rh in PS films has been investigated by reacting Rh sites with CO, $H_2,\;D_2,\;O_2\;NO,\;C_2H_2\;and\;C_2H_4$ in the temperature range $25-200^{\circ}C$. Various Rh-carbonyl, -hydride and -nitrosyl species formed in PS films are characterized by their infrared spectra. Rh complexes in PS film show interesting catalytic reactivities in the reactions such as hydrogenation of $C_2H_2\;and\;C_2H_4$, oxidation of CO, and reduction of NO by CO or $H_2$ gas under relatively mild conditions.

황산바나듐 모의용액으로부터 Alamine336에 의한 바나듐 용매추출의 최적조건 연구 (The Optimum Condition Analysis of Vanadium Solvent Extraction by Alamine336 from the Synthetic Vanadium Sulfate Solution.)

  • 안종관;안재우
    • 대한금속재료학회지
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    • 제46권12호
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    • pp.823-829
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    • 2008
  • The solvent extraction process for the recovery of vanadium from leaching solution of SCR(selective catalytic reduction) spent catalyst was investigated by using Alamine336 as an extractant. The effects of experimental conditions, such as initial pH and concentration of sulfate ion, and ammonia concentration of stripping solution were studied. The extraction percentage of vanadium were increased with the increase of initial pH of leaching solution and decreased with the increase of sulfate ion. More than 99% of vanadium in leaching solution were extracted and stripped at the A/O ratio of 1.0 in 2 stages. On the basis of these results, an optimum solvent extraction process which vanadium was effectively recovered from SCR spent catalyst was proposed.

정유 산업에서의 온실가스 포집 (CO2 Capture from the Petroleum Refining Industry)

  • 홍연기
    • 융복합기술연구소 논문집
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    • 제11권1호
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    • pp.13-18
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    • 2021
  • It is widely accepted that the prevention of global warming requires significant reductions in greenhouse gases, particularly CO2 emissions. Although fossil fuel-based power plants account for the majority of CO2 emissions, it is urgent to reduce CO2 emissions in industries that emit large amounts of CO2 such as steel, petrochemical, and oil refining. This paper examines the current status of CO2 emission in the domestic oil refining industry and CO2 emission sources in each unit process in the oil refining industry. Focusing on the previously developed CO2 capture process, cases and applicability of greenhouse gas reduction in FCC and hydrogen manufacturing processes, which are major processes constituting the oil refining industry, are reviewed.

Site-directed Mutagenesis of Five Conserved Residues of Subunit I of the Cytochrome cbb3 Oxidase in Rhodobacter capsulatus

  • Ozturk, Mehmet;Gurel, Ekrem;Watmough, Nicholas J.;Mandaci, Sevnur
    • BMB Reports
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    • 제40권5호
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    • pp.697-707
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    • 2007
  • Cytochrome $cbb_3$ oxidase is a member of the heme-copper oxidase superfamily that catalyses the reduction of molecular oxygen to the water and conserves the liberated energy in the form of a proton gradient. Comparison of the amino acid sequences of subunit I from different classes of heme-copper oxidases showed that transmembrane helix VIII and the loop between transmembrane helices IX and X contain five highly conserved polar residues; Ser333, Ser340, Thr350, Asn390 and Thr394. To determine the relationship between these conserved amino acids and the activity and assembly of the $cbb_3$ oxidase in Rhodobacter capsulatus, each of these five conserved amino acids was substituted for alanine by site-directed mutagenesis. The effects of these mutations on catalytic activity were determined using a NADI plate assay and by measurements of the rate of oxygen consumption. The consequence of these mutations for the structural integrity of the $cbb_3$ oxidase was determined by SDS-PAGE analysis of chromatophore membranes followed by TMBZ staining. The results indicate that the Asn390Ala mutation led to a complete loss of enzyme activity and that the Ser333Ala mutation decreased the activity significantly. The remaining mutants cause a partial loss of catalytic activity. All of the mutant enzymes, except Asn390Ala, were apparently correctly assembled and stable in the membrane of the R. capsulatus.

New Unsymmetric Dinuclear Copper(II) Complexes of Trans-disubstituted Cyclam Derivatives: Spectral, Electrochemical, Magnetic, Catalytic, Antimicrobial, DNA Binding and Cleavage Studies

  • Prabu, R.;Vijayaraj, A.;Suresh, R.;Jagadish, L.;Kaviyarasan, V.;Narayanan, V.
    • Bulletin of the Korean Chemical Society
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    • 제32권5호
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    • pp.1669-1678
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    • 2011
  • Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.