• Title/Summary/Keyword: high purity nitrogen #5

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Development of analysis method for high purity nitrogen using GC-FID/Methanizer (GC-FID/Methanizer를 이용한 고순도 질소의 순도분석법 개발)

  • Jei, You;Jin Bok, Lee;Jin Seog, Kim;Woonjung, Kim;Kiryong, Hong
    • Analytical Science and Technology
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    • v.35 no.6
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    • pp.249-255
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    • 2022
  • In this study, a new method for the analysis of high-purity nitrogen was developed. A gas chromatography-flame ionization detector (GC-FID) was used for purity analysis. Certified reference materials (CRMs) at a level of 3 µmol/mol of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4), which may exist in high-purity nitrogen, were prepared using the gravimetric method, and these CRMs were used for purity analysis. In this new method, ultra-high-purity and high-purity nitrogen were used as carrier gases. The impurities in high-purity nitrogen were quantitatively analyzed by comparing the differences in the area values of the GC chromatograms of the prepared CRMs. We purchased liquid nitrogen and three bottles of nitrogen gas, which were produced by three different manufacturers, using high-purity nitrogen. Furthermore, to validate the developed purity analysis method, the fraction of impurities in high-purity nitrogen was compared with the results of the typical purity analysis method. The comparison results were consistent within the expanded uncertainties (k = 2).

AlN preparation by Self-propagation High-temperature Synthesis (SHS) in Al-N2 and Al-N2-AIN system (Al-N2와 Al-N2-AlN계에서 고온자전연소법에 의한 AlN 합성)

  • 이재령;이익규;안종관;김동진;안양규;정헌생
    • Journal of Powder Materials
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    • v.11 no.4
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    • pp.294-300
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    • 2004
  • This study for preparation of aluminum nitride (AlN) with high purity was carried out by self-propagating high-temperature synthesis method in two different systems, $Al-N_{2}$ and $Al-N_{2}$-AlN, with the change of nitrogen gas pressure and dilution factor. On the occasion of $Al-N_{2}$ system, unreacted aluminum was detected in the product in spite of high nitrogen pressure, 10 MPa, This may be caused by obstructing nitrogen gas flow to inner part of molten and agglomerate of aluminum, formed in pre-heating zone. In $Al-N_{2}$-AlN system, AlN with a purity of 95% or ever can be prepared in the condition of $f_{Dil}\geq0.5$, $P_{N_{2}}\geq$ 1 MPa, and the purity can be elevated to 98% over in the condition of $f_{Dil}$ = 0.7 and $P_{N_{2}}$ = 10 MPa.

Effects of Sintering Temperature and Atmosphere on Densification of Hypereutectic Al-Si Alloy Powders (Al-20Si-5.5Fe-1.2Mg-0.5Mn 합금분말의 치밀화에 미치는 소결온도와 분위기의 영향)

  • Lee, Jae-Wook;Park, Sang-Bin;Yang, Sang-Sun;Kim, Yong-Jin
    • Journal of Powder Materials
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    • v.15 no.3
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    • pp.196-203
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    • 2008
  • The densification behavior of Al-20Si-5.5Fe-1.2Mg-0.5Mn powders was investigated through micro-structure analysis of sintered specimens. The specimens sintered in vacuum or in high purity (99.999%) nitrogen showed porous near-surface microstructures. The densification of near-surface part was enhanced by means of ultra-high purity (99.9999%) nitrogen atmosphere. The relationship between slow densification and oxide surfaces of Al alloy powders was discussed. And the effects of Mg addition, nitrogen gas, and humidity on densification were discussed. In addition, the rapid growth of primary Si crystals above the critical temperature was reported.

High-Purity Purification of Indole Contained in Coal Tar Absorption Oil by Extraction-Distillation-Crystallization Combination (추출-증류-결정의 조합에 의한 콜타르 흡수유 중에 함유된 인돌의 고순도 정제)

  • Kim, Su Jin
    • Applied Chemistry for Engineering
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    • v.25 no.3
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    • pp.330-336
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    • 2014
  • Purification of indole contained in model coal tar absorption oil was examined by extraction-distillation-crystallization combination. The absorption oil consists of nine components such as four kinds of nitrogen heterocyclic compounds (9.2% quinoline, 2.4% iso-quinoline, 4.7% indole, 2.4% quinaldine), three kinds of bicyclic aromatic compounds (14.2% 1-methylnaphthalene, 31.8% 2-methylnaphthalene, 23.5% dimethylnaphthalene), 5.5% biphenyl and 3.3% phenyl ether. 99.5% indole was recovered by combination of formamide extraction-distillation-solute crystallization using n-hexane. Furthermore, the recovery process of indole contained in coal tar absorption oil was studied by using the experimental results obtained by each operation of this work.

Research on the Methane Recovery from Landfill Gas by Applying Nitrogen Gas Separator Membrane (질소 분리용 막을 이용한 매립가스내 메탄 회수 연구)

  • Chun, Seung-Kyu
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.8
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    • pp.586-591
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    • 2013
  • This experiment was performed to enhance $CH_4$ purity of landfill gas by applying gas separator membrane for purified nitrogen gas production. 1:6 area ratios of $1^{st}$ to $2^{nd}$ membrane module was suitable for $CH_4$ recovery. After separation membrane system was installed, 249 tries were performed. Average permeability for $CH_4$ was 28.4% and for $CO_2$ was 94.3%. This can explain nitrogen gas separator membrane can be applied to collect $CH_4$ from LFG. However, nitrogen permeability only reached up to 16.5%. Therefore, the final purified landfill gas concentration was rounded up to 69.7% for $CH_4$, 4.3% for $CO_2$ and 26.0% for $N_2$. For the high degree of $CH_4$ purity, $N_2$ should be kept at least under 2.0% by controlling air inflow to landfill.

A Study on the Characteristics of Electro Polishing and Utility Materials for Transit High Purity Gas (청정도 가스 이송용 재료의 특성과 전해연마에 관한 연구)

  • Lee, Jong-Hyung;Park, Shin-Kyu;Yang, Seong-Hyeon
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.3
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    • pp.259-263
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    • 2004
  • In the manufacture progress of LCD or semiconductor, there are used many kinds of gas like erosion gas, dilution gas, toxic gas as a progress which used these gas there are required high puritize to increase accumulation rate of semiconductor or LCD materials work progress of semiconductor or LCD it demand many things like the material which could minimize metallic dust that could be occured by reaction between gas and transfer pipe laying material, illumination of the surface, emition of the gas, metal liquation, welding etc also demand quality geting stricted. Material-Low-sulfur-contend (0.007-0010), vacuum-arc-remelt(VAR), seamless, high-purity tubing material is recommend for enhance welding lower surface defect density All wetted stainless steel surface must be 316LSS elecrto polishinged with ${\leq}0.254{\mu}m$($10.0{\mu}in$) Ra average surface finish, $Cr/Fe{\geq}1.1$ and $Cr_2O_3$ thickness ${\geq}25{\AA}$ From the AES analytical the oxide layer thickness (23.5~36 angstroms silicon dioxide equivalent) and chromum to iron ratios is similar to those generally found on electropolished stainless steel., molybdenum and silicon contaminants ; elements characteristic of stainless steel (iron, nickel and chromium); and oxygen were found on the surface Phosphorus and nitrogen are common contaminants from the electropolish and passivation steps.

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A Scale-Up Test for Preparation of AlN by Carbon Reduction and Subsequent Nitridation Method (탄소환원질화법에 의한 AlN 제조 규모확대 시험결과)

  • Park, Hyung-Kyu;Kim, Sung-Don;Nam, Chul-Woo;Kim, Dae-Woong;Kang, Moon-Soo;Shin, Gwang-Hee
    • Resources Recycling
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    • v.25 no.5
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    • pp.75-83
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    • 2016
  • AlN powder was prepared by carbon reduction and subsequent nitridation method through the scale-up experiments of 0.7 ~ 1.5 kg per batch. AlN powder was synthesized using the mixture of $Al_2O_3$ powder and carbon black at $1,550{\sim}1,750^{\circ}C$ for 0.5 ~ 4 hours under nitrogen atmosphere (flow rate of nitrogen gas: $10{\sim}40{\ell}/min$) at $2.0{\times}10^{-1}Torr$. Experimental results showed that $1,700{\sim}1,750^{\circ}C$ for the reaction temperature, 3 hr for reaction time, and $40{\ell}/min$ for the flow rate of nitrogen gas were the optimal conditions. Also, in order to remove carbon in the synthesized AlN, the remained carbon was removed at $650{\sim}750^{\circ}C$ for 1 ~ 2 hr using horizontal tube furnace. The results showed that 1 : 3.2 mol ratio of $Al_2O_3$ to carbon black, reaction temperature of $750^{\circ}C$, reaction time of 2 hours, rotating speed of 1.5 rpm under atmosphere condition were the optimal conditions. Under these conditions, high-purity AlN powder over 99% could be prepared: carbon and oxygen contents of the AlN powder were 835 ppm and 0.77%, respectively.

A Study on Nitridation and Oxidation Reaction of Titanium Powder (금속티타늄분말의 질화반응과 산화반응에 관한 연구)

  • Lee, Young-Ki;Sohn, Yong-Un;Cho, Young-Soo;Kim, Yong Seog;Kim, Suk-Yoon
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.2
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    • pp.137-148
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    • 1995
  • The nitridation kinetics of titanium powder were studied by isothermal and non-isothermal (dynamic) methods in high purity nitrogen under I atm pressure. For the comparison with nitridation, the oxidation kinetics of titanium powder were also studied in dry oxygen at I atm pressure. An automatic recording electrobalance was used to measure the weight gain as a function of time and temperature. For the reaction with nitrogen, the nitride was formed at over $700^{\circ}C$. The reaction with nitrogen followed the parabolic rate law, and the activation energy was calculated to be 31 kcal/mol in the isothermal method (above $900^{\circ}C$). The non-stoichiometric TiNx has been synthesized by the nitridation at a proper temperature and time, followed by the homogenizing treatment above $1100^{\circ}C$. In comparison with the stoichiometric $TiN_{1.0}$ and the non-stoichiometric TiNx ($TiN_{0.5}$ and $TiN_{0.65}$), the hot oxidation characteristics of the former is superior to that of the latter. However, both non-stoichiometric nitrides make little difference in the hot oxidation characteristics.

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ANALYSIS OF RADIOACTIVE IMPURITIES IN ALUMINA AND SILICA USED FOR ELECTRONIC MATERIALS

  • Lee Kil-Yong;Yoon Yoon-Yeol;Cho Soo-Young;Kim Yong-Je;Chung Yong-Sam
    • Nuclear Engineering and Technology
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    • v.38 no.5
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    • pp.423-426
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    • 2006
  • A developed neutron activation analysis(NAA) and gamma-spectrometry were applied to improve the analytical sensitivity and precision of impurities in electronic-circuit raw materials. It is well known that soft errors in high precision electronic circuits can be induced by alpha particles emitted from naturally occurring radioactive impurities such as U and Th. As electronic circuits have recently become smaller in dimension and higher in density, these alpha-particle emitting radioactive impurities must be strictly controlled. Therefore, new NAA methods have been established using a HTS(Hydraulic Transfer System) irradiation facility and a background reduction method. For eliminating or stabilizing fluctuated background caused by Rn-222 and its progeny nuclides in air, a nitrogen purging system is used. Using the developed NAA and gamma-spectrometry, ultra trace amounts of U(0.1ng/g) and Th(0.01ng/g) in an alumina ball and high purity silica used for an epoxy molding compound (EMC) could be determined.

Analysis of biomarkers with tunable infrared gas sensors (가변 파장형 적외선 가스 센서에 의한 생체표지자 분석)

  • Yi, Seung Hwan
    • Journal of Sensor Science and Technology
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    • v.30 no.5
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    • pp.314-319
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    • 2021
  • In this study, biomarkers were analyzed and segmented using tunable infrared gas sensors after performing the principal component analysis. The free spectral range of the device under test (DUT) was around 30 nm and DUT-5580 yielded the highest output voltage property among the others. The biomarkers (isoprophyl alcohol, ethanol, methanol, and acetone solutions) were sequentially mixed with deionized water and their mists were carried into the gas chamber using high-purity nitrogen gas. A total of 17 different mixed gases were tested with three tunable infrared gas sensors, namely DUT-3144, DUT-5580, and DUT-8010. DUT-8010 resolved the infrared absorption spectra of whole mixed gases. Based on the principal component analysis with each DUT and their combinations, each mixed gas and the trends in increasing gas concentration could be well analyzed when the contributions of the eigenvalues of the first and second were higher than 70% and 10%, respectively, and their sum was greater than 90%.