• Title/Summary/Keyword: Waste Catalyst

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Investigating adsorption ion characteristics on cobalt oxides catalyst in electrolysis of waste alkaline solutions using ab-initio study (제일원리 전산모사법을 이용한 폐양액 수전해용 코발트 산화물 촉매의 흡착 이온 특성 연구)

  • Juwan Woo;Jong Min Lee;MinHo Seo
    • Journal of the Korean institute of surface engineering
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    • v.56 no.6
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    • pp.427-436
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    • 2023
  • In the industry, it is recognized that human activities significantly lead to a large amount of wastewater, mainly due to the increased use of water and energy. As a result, the growing field of wastewater resource technology is getting more attention. The common technology for hydrogen production, water electrolysis, requires purified water, leading to the need for desalination and reprocessing. However, producing hydrogen directly from wastewater could be a more cost-effective option compared to traditional methods. To achieve this, a series of first-principle computational simulations were conducted to assess how waste nutrient ions affect standard electrolysis catalysts. This study focused on understanding the adsorption mechanisms of byproducts related to the oxygen evolution reaction (OER) in anion exchange membrane (AEM) electrolysis, using Co3O4 as a typical non-precious metal catalyst. At the same time, efforts were made to develop a comprehensive free energy prediction model for more accurate predictions of OER results.

A Study on NOx Removal Efficiency using SNCR Process in the Industrial Waste Incineration Plant (산업폐기물 소각로에서 SNCR공정에 의한 NOx 제거효율에 관한 연구)

  • Ryu Hae-Yeol;Kim Min-Choul;Jung Jong-Hyeon;Lee Gang-Woo;Chung Jin-Do
    • Journal of Environmental Health Sciences
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    • v.31 no.4 s.85
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    • pp.332-339
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    • 2005
  • The environmental regulations in the world has been reinforced and many nations has devoted themselves to the development of cost-effective technology. Selective catalyst reduction(SCR) and selective non-catalyst reduction (SNCR) processes are mainly used to treat nitrogen oxidants generated from fossil-fuel combustion. One of these typical technologies for reduction of do-NOx is SNCR process has increased continuously because of the low cost for building and maintenance. Nevertheless the researches on the application to real scale plant by the reductant like Urea are rarely studied. In this paper, an experimental investigations were performed on the SNCR process in the industrial waste incineration plant. With no reducing agent, the concentration of NOx stayed in around 180 ppm $(O_2\;12\%)$ with the exhausting temperature of $950^{\circ}C$ and changed within the range of 20 ppm to remain relatively consistent. When $10\;wt\%)$ of a solution was added, the efficiency of denitrification reached above $61.4\%$ with the NSR of 2.0 and the exhausting temperature of $950^{\circ}C.$ When the concentration of the urea solution was set to $10\;wt\%$ and the sprinkling to four nozzles, the reaction temperature was reduced to about $50~100^{\circ}C$ with a mixture of $10\;wt\%\;CH_3OH\;and\;5wt\%\;Na_2CO_3$ in $40\;wt\%$ of the solution. The NOx removal efficiency increased to $78.4\%,$ achieving a broader and expansive range of reaction temperatures than the addition of an unmixed pure solution.

Removal of Impurities by Magnetic Separation from Waste Fluidized Cracking Catalyst for Its Reuse (폐FCC 촉매의 재활용 과정에서 자력 선별법에 의한 불순물 제거 연구)

  • Ban Bong-Chan;Lee Jin-Suk;Kim Dong-Su
    • Resources Recycling
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    • v.12 no.1
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    • pp.55-64
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    • 2003
  • Presently, the reuse of waste FCC catalysts, which generated from the refining process of crack oil, after the removal of con-taminated metallic impurities have not been attempted domestically yet because the separation technology f3r the impurities from waste catalysts has not been established. As a basic study far the reusable portion from the waste FCC catalysts and treatment of metallic impurities are assured, there will be invoked an significant contribution not only in the recycling of abandoned wastes up to date but also in the treatment efficiency of wastes and extraction of economical benefits from them. The magnetic separation of impurities such as Fe, Ni, and V, from waste FCC catalyst has been attempted with or without its pre-oxidation at high temperature for the purpose of its reuse. The results showed that the separability of impurities by magnetic force was high far non-preoxidized catalysts compared with preoxidized ones, and employment of screen-type matrix showed a higher separation efficiency than ball-type matrix. The separability increased with the strength of magnetic field, and the method of ball matrix has separation efficiency of maximum 51.10%. The amount of metallic impurities was in the decreasing order of V, Ni, and Fe depending upon ICP analysis.

A study on the properties of artificial aggregates containing bottom ash from the power plant and waste catalyst slag (화력발전소 바닥재와 폐촉매 슬래그로 제조된 인공골재의 특성 연구)

  • Jo, Si-Nae;Kang, Seung-Gu
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.22 no.4
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    • pp.200-206
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    • 2012
  • The artificial aggregate composing of coal bottom ash and waste catalyst slag (7 : 3, wt%) were fabricated using direct sintering method and, the bloating properties of aggregates were investigated as a function of raw material particle size and sintering temperature. Most of the artificial aggregates sintered at over $1150^{\circ}C$ showed the bloating phenomenon regardless of particle size of the raw materials. Consequently, the specific gravity of the aggregates was drastically decreased to below 1.4. The aggregates containing waste catalyst slag of $90{\mu}m$ under among the W-series specimens, however, did not show the noticeable bloating phenomenon. For the aggregates sintered at lower temperature as $1050{\sim}1150^{\circ}C$, the specific gravity increased with particle size of raw materials. Also, the water absorption of all aggregates decreased with the sintering temperature. The aggregates fabricated in this study met the lightweight aggregate standard showing the specific gravity 1.7~1.4 and water absorption 8~19 % and, therefore, can be applicable for the various fields.

Change in Engine Exhaust Characteristics Due to Automotive Waste Heat Recovery (엔진 배기 폐열회수로 인한 배기 특성 변화)

  • Kim, Kibum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4723-4728
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    • 2014
  • In this study, a thermoelectric module (TEM) and a diesel engine were modeled using 1-D commercial software AMESim, and the performance of the TEM was evaluated when the engine was operated under the NEDC driving cycle. The goal of TEM modeling was to investigate not only the waste heat recovery (WHR) rate and energy converting efficiency, but also the heat transfer rate by taking the materials characteristics into account. In addition, a diesel oxidation catalyst (DOC) was designed, and it was found that the waste heat recovery with TEM affects the activation of DOC and alters engine exhaust composition. The simulation indicated that the WHR using TEM is beneficial for decreasing the fuel consumption of vehicles, but the reduction in the exhaust temperature affects the activation of DOC, resulting in an approximately 14% increase in CO and HC emissions. Therefore, the effect of waste heat recovery on the automotive emission characteristics must be considered in the development of automotive engine WHR systems.

A Study on the Process Improvement of RJ-4 fuel Preparation using a Heteropoly Acid Catalyst (Heteropoly acid촉매를 이용한 RJ-4연료의 제조공정 개선연구)

  • Jeong Byung-Hun;Han Jeong-Sik;Choi Chang-Sun;Hong Myung-Pyo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.229-232
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    • 2005
  • The study on the improvement of manufacturing process of RJ-4 liquid fuel that have high flash point, was carried out. In preparing of RJ-4 using commercially available MCPD, 1st, 2nd hydrogenation and isomerization reaction were enabled 1 step continuous process by combined use of heteropoly phosphoroustungstic cesium salt catalyst and 2nd stage-heat-controllable reactor. Also when heteropolyacid cesium salt was used as a isomerization catalyst instead of aluminum chloride, formation rate of exe-THDMCPD was higher, the catalyst could be easily separable from product and there was no production of waste acid, so this new reaction condition was confirmed as the environment friendly process.

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An Optimization of Synthesis Method for High-temperature Water-gas Shift Reaction over Cu-CeO2-MgO Catalyst (고온수성가스전이반응 적용을 위한 Cu-CeO2-MgO 촉매의 제조방법 최적화)

  • I-Jeong Jeon;Chang-Hyeon Kim;Jae-Oh Shim
    • Clean Technology
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    • v.29 no.4
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    • pp.321-326
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    • 2023
  • Recently, there has been a growing interest in clean hydrogen energy that does not emit carbon dioxide during combustion due to the increasing focus on carbon neutral. Research related to hydrogen production continues, and in this study, we applied waste-derived synthesis gas to the water-gas shift reaction to simultaneously treat waste and produce high-purity hydrogen. To enhance catalytic activity in the high-temperature water-gas shift (HT-WGS) reaction, magnesium was used as a support material alongside cerium. Cu-CeO2-MgO catalysts were synthesized, with copper acting as the active component for the HT-WGS reaction. A study on the catalytic activity based on the preparation method was conducted, and the Cu-CeO2-MgO catalyst prepared by impregnation method exhibited the highest activity in the HT-WGS reaction. The observed superior performance of the Cu-CeO2-MgO catalyst prepared through the impregnation method can be attributed to its significantly higher oxygen storage capacity and amount of active Cu species.

Chemical Active Liquid Membranes in Inorganic Supports for Metal Ion Separations

  • Yi, Jongheop
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.10a
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    • pp.8-11
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    • 1994
  • Disposal of hazardous ions in the aqueous streams is a significant industrial waste problem.. Waste streams from electronics, electroplating, and photographic industries contain metal ions such as copper, nickel, zinc, chromium(IV), cadmium, aluminum, silver, and gold, amongst others in various aqueous solutions such as sulfates, chlorides, fluorocarbons, and cyanides. Typical plating solutions having similar compositions are listed in Table 1. Spent process streams in catalyst manufacturing facilities also contain precious metals such as Ag, Pt, and Pd. Developing an effective recovery process of these metal ions for reuse is important.

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Kinetics of Hydrogen Rich Ethanol as Reductant for HC-SCR over $Al_2O_3$ Supported Ag Catalyst (Ag/$Al_2O_3$ 촉매하의 HC-SCR에서 수소 풍부 에탄올의 반응 특성)

  • Lee, Ju-Heon;Park, Jeong-Whan;Kim, Seong-Soo;Yoo, Seung-Joon;Kim, Jin-Gul
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.6
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    • pp.519-525
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    • 2010
  • Ethanol was used as reductant to remove $NO_x$ over Ag/$Al_2O_3$ catalyst via SCR from stationary emission source. Among the tested hydrocarbon reductants, ethanol showed highest de-$NO_x$ performance over the Ag/$Al_2O_3$ catalyst. De-$NO_x$ efficiency of about 83% was obtained in the condition of GHSV 20,000 $hr^{-1}$, $NO_x$ 200 ppm, CO 200 ppm, $O_2$ 13%, $H_2O$ 5% and mole ratio of ethanol/$NO_x$ = 2 between temperature of $300^{\circ}C$ and $400^{\circ}C$. While $SO_2$ presence in the $NO_x$ exhaust suppressed the catalytic activity, catalyst with acid (0.7% $H_2SO_4$) treatment of catalyst showed higher catalytic activity, where In-Situ DRIFT showed S presence over catalyst surface was increased after acid treatment of catalyst. From in-situ DRIFT and SCR results, it was concluded that sulfur presence over the surface of Ag/$Al_2O_3$ catalyst was the dominant factor to control the de-$NO_x$ reaction yield via HC-SCR from the exhausted gas including $SO_2$.

A Study on DMT Synthesis Using Crude TPA Sludge Generated from PET Alkaline Waste Water as Raw Materials (PET 감량폐약으로부터 발생되는 crude TPA sludge를 원료로 한 DMT 합성에 관한 연구)

  • Cho, Hwan;Kim, Jong Bo;Jeong, Hee Cheon;Jeon, Byung Dae
    • Textile Coloration and Finishing
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    • v.7 no.2
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    • pp.9-16
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    • 1995
  • When alkaline waste water of PET fabric is treated with sulfuric acid, undegradable material, crude TPA sludge is generated, so that treatment has a serious problem. The result of DMT synthesis using crude TPA sludge generated from PET alkaline waste water were as follows: 1. When crude TPA generated from alkaline waste water is reactioned with methanol under catalyst of sulfuric acid, pure DMT can be obtained. 2. In DMT synthesis from crude TPA, addition of copper sulfate can increase yield, and increasing the amount of sulfuric acid can shorten reaction time.

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