• Title/Summary/Keyword: Removal process

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A Study on Wet Process of $H_2S$ removal with MDEA (MDEA를 이용한 $H_2S$의 습식탈황 고찰)

  • Han, Keun-Hee;Jo, A-Ra;Lee, Jong-Seup;Min, Byoung-Moo
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.238-241
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    • 2008
  • In this study, absorption behaviors of absorbents and additives were measured for removing of $H_2S$ and COS from syn-gas in IGCC process, such as MDEA and HMDA. The experimental variables were concentration of absorbents and reaction temperature. From these experiments, the loading ratios of $H_2S$ were decreased with increasing of concentration of absorbents and absorption temperatures. These results will be applied to basic data for designing of $H_2S$ removal process in IGCC.

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인공심장판막의 현황

  • 김형묵
    • Journal of Biomedical Engineering Research
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    • v.10 no.2
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    • pp.94-96
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    • 1989
  • Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained.

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Petroleum Refinery Effluents Treatment by Advanced Oxidation Process with Methanol

  • Shoucheng, Wen
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.76-79
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    • 2014
  • Petroleum refinery effluents are waste originating from industries primarily engaged in refining crude oil. It is a very complex compound of various oily wastes, water, heavy metals and so on. Conventional processes are unable to effectively remove the chemical oxygen demand (COD) of petroleum refinery effluents. Supercritical water oxidation (SCWO) was proposed to treat petroleum refinery effluents. In this paper, methanol was used to investigate co-oxidative effect of methanol on petroleum refinery effluents treatment. The results indicated that supercritical water oxidation is an effective process for petroleum refinery effluents treatment. Adding methanol caused an increase in COD removal. When reaction temperature is $440^{\circ}C$, residence time is 20 min, OE is 0.5 and initial COD is 40000 mg/L, and COD removal increases 8.5%.

An Analysis on the Material Removal Mechanism of Chemical-Mechanical Polishing Process Part I: Coupled Integrated Material Removal Modeling (화학-기계적 연마 공정의 물질제거 메커니즘 해석 Part I: 연성 통합 모델링)

  • Seok, Jong-Won;Oh, Seung-Hee;Seok, Jong-Hyuk
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.2 s.19
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    • pp.35-40
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    • 2007
  • An integrated material removal model considering thermal, chemical and contact mechanical effects in CMP process is proposed. These effects are highly coupled together in the current modeling effort. The contact mechanics is employed in the model incorporated with the heat transfer and chemical reaction mechanisms. The mechanical abrasion actions happening due to the mechanical contacts between the wafer and abrasive particles in the slurry and between the wafer and pad asperities cause friction and consequently generate heats, which mainly acts as the heat source accelerating chemical reaction(s) between the wafer and slurry chemical(s). The proposed model may be a help in understanding multi-physical interactions in CMP process occurring among the wafer, pad and various consumables such as slurry.

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A Study on Repairing Retired Underground Buried Pipes Using RTM (RTM을 이용한 노후 지하 매설관의 보수-보강에 관한 연구)

  • 진우석;권재욱;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.249-252
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    • 2000
  • To overcome problems of excavation technology far repairing or replacing underground buried pipes which are worn out or damaged, various trenchless repair-reinforcement technologies have been invented. But these trenchless technologies also have many problems in the aspect of economy and convenience of operation. In this research, the repair-reinforcement process using RTM (Resin Transfer Molding) which can solve problems of present trenchless technologies was developed. The resin wetting and void removal during RTM process to form large composite structures inside of buried pipes were experimentally investigated. From the experiment, it was found that the new technology had advantage over conventional methods by employing appropriate process parameters and void removal vents.

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Frameworks for NHPP Software Reliability Growth Models

  • Park, J.Y.;Park, J.H.;Fujiwara, T.
    • International Journal of Reliability and Applications
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    • v.7 no.2
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    • pp.155-166
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    • 2006
  • Many software reliability growth models (SRGMs) based on nonhomogeneous Poisson process (NHPP) have been developed and applied in practice. NHPP SRGMs are characterized by their mean value functions. Mean value functions are usually derived from differential equations representing the fault detection/removal process during testing. In this paper such differential equations are regarded as frameworks for generating mean value functions. Currently available frameworks are theoretically discussed with respect to capability of representing the fault detection/removal process. Then two general frameworks are proposed.

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DEVELOPMENT OF MEMBRANE AND COLD-CONDENSATION PROCESS FOR REMOVAL AND RECOVERY OF VOLATILE ORGANIC COMPOUNDS

  • Kim, Sung-Soo;Lee, Jong-Hwa;Kim, Hyunki;Kim, Sang-Yong
    • Proceedings of the Membrane Society of Korea Conference
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    • 2003.07a
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    • pp.69-72
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    • 2003
  • Volatile organic compounds (VOC) cause air pollution problem and deterioration of atmosphere of petrochemical and fine chemical plants. Hybrid process of membrane and cold-condensation were developed and it effectively removed and recycled the VOC. Operation parameters of the process were optimized to attain hish removal and recycle of VOC. Composite membranes for organic vapor separation were developed in this work by PDMS coating and plasma polymerization on polypropylene and polysulfone support membranes. PDMS and various silicone monomers were tested for several organic vapors such as benzene, toluene, TCE, and HCFC, which are produced in petrochemical and fine chemical industry and causes air pollution problems if are released to atmosphere. Composite membranes prepared in this work showed appreciable performance in terms of organic vapor removal and reuse. Performance variation of the membranes was correlated with their surface characteristics.

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Automatic Addition Control of the External Carbon Source by the Measurement of ORP in Biological Nitrogen Removal Process (생물학적 질소 제거공정에서 ORP 측정을 통한 외부탄소원의 자동 주입 제어)

  • Shin, Choon-Hwan
    • Journal of Environmental Science International
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    • v.21 no.3
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    • pp.383-390
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    • 2012
  • For the cost-effective biological nitrogen removal (BNR) process whose characteristics of influent have low COD/N ratios, the automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in an anoxic reactor has been developed. In this study, it was carried out with a pilot-scale Bardenpho process which was consisted of anoxic 1, aerobic 1, aerobic 2, anoxic 2, aerobic 3 tank and clarifier. Firstly, the correlation coefficient ($R^2$) of the dosage of external carbon source and ORP value was about 0.97. Consequently, the automatic control system using ORP showed that the dosage of external carbon source was decreased by about 20% compared with a stable dosage of 75 mg/L based on the COD/N ratio of the anoxic influent.

CMP properties of $SnO_2$ thin film by different slurry (슬러리 종류에 따른 $SnO_2$ 박막의 광역평탄화 특성)

  • Lee, Woo-Sun;Choi, Gwon-Woo;Ko, Pil-Ju;Kim, Wan-Tae;Seo, Yong-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.389-392
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    • 2004
  • As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) layer with free-defect. The effect of alternative commerical slurries pads, and post-CMP cleaning alternatives are discuess, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. we investigated the performance of $SnO_2$-CMP process using commonly used silica slurry, ceria slurry, tungsten slurry. This study shows removal rate and non-uniformity of $SnO_2$ thin film used to gas sensor by using Ceria, Silica, W-Slurry after CMP process. This study also shows the relation between particle size and CMP with particle size analysis of used slurry.

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CMP properties of $SnO_2$ thin film ($SnO_2$ 박막의 CMP 특성)

  • Lee, Woo-Sun;Choi, Gwon-Woo;Ko, Pil-Ju;Hong, Kwang-Jun;Seo, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.184-187
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    • 2003
  • As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) lyaer with free-defect. The effect of alternative commerical slurries pads, and post-CMP cleaning alternatives are discuess, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. we investigated the performance of $SnO_2-CMP$ process using commonly used silica slurry, ceria slurry, tungsten slurry. This study shows removal rate and nonuniformity of $SnO_2$ thin film used to gas sensor by using Ceria, Silica, W-Slurry after CMP process. This study also shows the relation between partical size and CMP with partical size analysis or used slurry.

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