• Title/Summary/Keyword: Energy separation

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Effects of Operating Variables on Solid Separation Rate in Two-interconnected Fluidized Beds System for Selective Solid Circulation (선택적 고체순환을 위한 2탑 유동층 시스템에서 고체분리속도에 미치는 조업변수들의 영향)

  • Ryu, Ho-Jung;Jin, Gyoung-Tae;Bae, Dal-Hee;Kim, Hong-Ki
    • Korean Chemical Engineering Research
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    • v.47 no.3
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    • pp.355-361
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    • 2009
  • Effects of operating variables on solid separation rate in two-interconnected fluidized beds system for selective solid circulation have been investigated. Coarse(212~300 or $425{\sim}600{\mu}m$) and fine($63{\sim}106{\mu}m$) particles were separated using the solid separator and the solid separation rate was ranged from 66 to 987 g/min. The solid separation rate increased as the gas velocity through the solid injection nozzle, solid height, diameter of solid injection nozzle, particle size of coarse particles, aperture of the solid separator, and weight fraction of fines in the solid mixture increased. However, the effect of the fluidization velocity was negligible.

CO2 Capture & Separation in Microporous Materials: A Comparison Between Porous Carbon and Flexible MOFs (다공성 물질을 이용한 CO2 포집 및 분리: 다공성 탄소와 유연한 MOF 비교 연구)

  • Jung, Minji;Park, Seoha;Oh, Hyunchul;Park, Kwi-il
    • Korean Journal of Materials Research
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    • v.28 no.7
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    • pp.417-422
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    • 2018
  • The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for $CO_2$ reduction application. The textural properties of these microporous materials are investigated, and their $CO_2$ storage capacity and separation performance are evaluated. Owing to the combined effects of $CO_2-Amino$ interaction and its flexibility, a $CO_2$ uptake of $2.5mmol\;g^{-1}$ is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, $CH_4$ uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for $CO_2/CH_4$ separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher $CO_2$ uptake of $4.7mmol\;g^{-1}$ is also observed at 20 bar 298 K. Furthermore, the $CH_4$ storage capacity is $2.9mmol\;g^{-1}$ at 298 K and 20 bar. To evaluate the $CO_2$ separation performance, the selectivity based on ideal adsorption solution theory for $CO_2/CH_4$ binary mixtures on the presented porous materials is investigated.

Recovery of Valuable Minerals from Sea Water by Membrane Separation and Adsorption Process: A Review (막 분리와 흡착 과정을 통한 해수로부터의 주요 광물 회수: 리뷰)

  • Jeon, Sungsu;Patel, Rajkumar
    • Membrane Journal
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    • v.32 no.1
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    • pp.13-22
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    • 2022
  • Ever increasing global energy demand gives rise to uncontrollable environmental pollution. Demand on fossil fuel and consequent carbon emission leads to global warming and climate change. Nuclear energy is an alternative source to generate clean energy but mining of nuclear fuel is associated with harmful chemicals. Mining of valuable minerals from sea water by membrane separation process is a cost effective along with environmental friendly process. Separation and adsorption based mining of valuable minerals from sea water are another efficient process. Recovery of actinides from rare earth elements are very challenging and expensive process. Pressure driven membrane separation process is economically more viable along with environmental process. In this review membrane separation process are based on polyether sulfone, polyamide, polyimide, polyamidoxine and hybrid membranes. In case of adsorption process, mainly amidoxime kind of adsorbent are discussed.

A rapid separation of Cs, Sr and Ba using gas pressurized extraction chromatography with inductively coupled plasma-mass spectrometry

  • Sojin Jeong;Jihye Kim;Hanul Cho;Hwakyeung Jeong;Byungman Kang;Sang Ho Lim
    • Analytical Science and Technology
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    • v.37 no.2
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    • pp.123-129
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    • 2024
  • We present a rapid method for the determination of Cs, Sr, and Ba, heat generators found in highly active liquid wastes, by gas-pressurized extraction chromatography (GPEC) using a column containing a cation-exchange resin. GPEC is a microscale column chromatographic technique that uses a constant flow rate of solvent (0.07 mL/min) with pressurized nitrogen gas supplied through a valve. In particular, because this method uses a small sample volume (a few hundred microliters), it produces less chemical waste and allows for faster separation compared to traditional column chromatography. In this study, we evaluated the separation of Cs, Sr, and Ba using GPEC. The eluate from the column (GPEC or conventional column chromatography) was quantitatively analyzed using inductively coupled plasma-mass spectrometry to measure the column recovery and precision. The column reproducibility of the proposed GPEC system (RSDs of recoveries) ranged from 2.7 to 4.1 %, and the column recoveries for the three elements ranged from 72 to 98% when aqueous HCl was used as the eluent. The GPEC results are slightly different in efficiency and separation resolution compared to those of conventional column chromatography because of the differences in the eluent flow rate as well as the internal diameter and length of the column. However, the two methods had similar recoveries for Cs and Sr, and the precision of GPEC was improved by two-fold. Remarkably, the solvent volume required for GPEC analysis was five times lower than that of the conventional method, and the total analysis time was 11 times shorter.

An Experimental Study on the Energy Separation in the Ratio of Nozzle Area of a tow Pressure Vortex Tube (저압용 보텍스튜브의 노즐면적비에 따른 에너지 분리특성에 관한 실험적 연구)

  • 오동진;최정원
    • Journal of Energy Engineering
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    • v.13 no.1
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    • pp.34-39
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    • 2004
  • The process of energy separation in a low pressure vortex tube with compressed air as a working medium is studied in detail. Experimental data of the temperature of the cold and hot air leaving the vortex tube are presented. The variation of the maximum wall temperature along the inner surface of a vortex tube and the temperature distribution in a vortex tube provide useful information about the location of the stagnation point of the flow field at the axis of the vortex tube Analysis of the results enabled to find the optimum ratio of nozzle area and the optimum shape of an orifice. From this optimum geometric setup of a low pressure and big vortex tube the effectiveness of energy separation was better than a high pressure and small vortex tube.

A Study on Thermodynamics for Compositional Separation in Co-Cr magnetic Alloy Films (Co-Cr 자성합금 박막의 조성적 상분리 현상의 열역학적 고찰)

  • Song, O-Seong;Jeon, Jeon-An
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.341-344
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    • 1999
  • We reported compositional separation(CS) into Co-enriched and Cri-enriched components inside the grains of Co-Cr based thin films prepared by rf sputtering. CS strongly depends on the sputtering conditions of substrate temperature and target composition. Tuning the microstructure of the Co-Cr films is important in order to employ the CS for high-density magnetic recording. We investigated the origin of CS from thermodynamic viewpoint. We employ a spinodal decomposition-like model to describe the origin of the CS in Co-Cr films. We consider the total free energy of the Co-Cr films as the sum of several free energies of; 1) thermodynamic mixing entropy of a binary solid solution, 2) magnetic ordering interaction(MOI) energy below the Curie temperature, and 3) excess interaction energy(XS) caused by the sputtering process as a function of temperature and composition. Those energies distorted the total free energy like the spinodal decomposition and caused the compositionally separated fine microstructure inside the grains. If the second derivative of the total free energy with respect to Cr composition becomes negative at a given substrate temperature, we may observe a metastable compositional separation inside the Co-Cr alloy films. We expect to exploit the microstructure of CS for ultra-high density magnetic recording.

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Preliminary Study on Separation of Germanium and Gallium for Development of a 68Ge/68Ga Generator

  • Lee, Heung Nae;Kim, Sang Wook;Park, Jeong Hoon;Kim, Injong;Yang, Seung Dae;Hur, Min Goo
    • Journal of Radiation Industry
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    • v.5 no.2
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    • pp.101-106
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    • 2011
  • The separation of germanium and gallium ion with metal oxide was introduced into the development of $^{68}Ge/^{68}Ga$ generator. Germanium and gallium within mixed solution were respectively separated by using a liquid-liquid extraction and a column chromatographic method. The separation of Ge within high concentrated hydrochloric and sulfuric acid was conducted by the extraction to $CCl_4$ and the back-extraction to 0.05 M HCl. An optimum condition of the extraction by $CCl_4$ was in 5~7 M HCl and efficiency was around 80%. The gallium was selectively separated by using $Al_2O_3$ among metal oxides as sorbents from the mixed solution in 0.04~0.10 M HCl condition.

Hydrogen Isotope Separation by using Zeolitic lmidazolate Frameworks (ZIF-11) (ZIF-11을 이용한 수소 동위원소 분리)

  • Lee, Seulji;Oh, Hyunchul
    • Korean Journal of Materials Research
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    • v.30 no.12
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    • pp.655-659
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    • 2020
  • Hydrogen isotopes (i.e. deuterium and tritium) are supplied to the tokamak in the International Thermonuclear Experimental Reactor (ITER) fuel cycle. One important part of the ITER fuel cycle is the recycling of unused fuel back to the tokamak, as almost 99 % of fuel is unburned during fusion reaction. For this, cryogenic distillation has been used in the isotope separation system (ISS) of ITER, but this technique tends to be energy-intensive and to have low selectivity (typically below 1.5 at 24 K). Recently, efficient isotope separation by porous materials has been reported in the so-called quantum sieving process. Hence, in this study, hydrogen isotope adsorption behavior is studied using chemically stable ZIF-11. At low temperature (40 K ~ 70 K), the adsorption increases and the sorption hysteresis becomes stronger as the temperature increases to 70K. Molar ratio of deuterium to hydrogen based on the isotherms shows the highest (max. 14) ratio at 50 K, confirming the possibility of use as a potential isotope separation material.

Selective adsorption of Ba2+ using chemically modified alginate beads with enhanced Ba2+ affinity and its application to 131Cs production

  • Kim, Jin-Hee;Lee, Seung-Kon
    • Nuclear Engineering and Technology
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    • v.54 no.8
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    • pp.3017-3026
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    • 2022
  • The 131Cs radioisotope with a short half-life time and high average radiation energy can treat the cancer effectively in prostate brachytherapy. The typical 131Cs production processes have a separation step of the cesium from 131Ba to obtain a high specific radioactivity. Herein, we suggested a novel 131Cs separation method based on the Ba2+ adsorption of alginate beads. It is necessary to reduce the affinity of alginate beads to cesium ions for a high production yield. The carboxyl group of the alginate beads was replaced by a sulfonate group to reduce the cesium affinity while reinforcing their affinity to barium ions. The modified beads exhibited superior Ba2+ adsorption performances to native beads. In the fixed-bed column tests, the saturation time and adsorption capacity could be estimated with the Yoon-Nelson model in various injection flow rates and initial concentrations. In terms of the Cs elution, the modified alginate showed better performance (i.e., an elution over 88%) than the native alginate (i.e., an elution below 10%), indicating that the functional group modification was effective in reducing the affinity to cesium ions. Therefore, the separation of cesium from the barium using the modified alginate is expected to be an additional option to produce 131Cs.

Separation of Plutonium Oxidation States by Ion Chromatography (이온크로마토그래피를 이용한 산화수별 플루토늄의 분리)

  • Kim, Seung Soo;Jun, Kwan Sik;Kang, Chul Hyung
    • Analytical Science and Technology
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    • v.14 no.1
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    • pp.28-33
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    • 2001
  • The ion chromatography for the separation of plutonium species which are suggested to be $Pu^{3+}$, $Pu^{4+}$, $PuO_2{^+}$ and $PuO_2{^{2+}}$ in natural water was studied. Two separation methods were performed; 1) two-column method containing each of $SiO^-$ and SiO-$SO_3{^-}$ cation exchanger, 2) IC with AG11 column and the eluent of oxalate/nitric acid. Separation conditions for $Eu^{3+}$, $Th^{4+}$, $NpO_2{^+}$, $UO_2{^{2+}}$ in place of plutonium species were acquired from preliminary tests. When these conditions were applied to separate the plutonium species, two-column method was separated them successfully. However, the IC method with oxalate eluent was difficult in the separation of plutonium species due to the change of $Pu^{3+}$ and $PuO_2{^{2+}}$ to $Pu^{4+}$ and $PuO_2{^+}$ respectively.

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